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Sample records for sustained delivery device

  1. Transscleral sustained vasohibin-1 delivery by a novel device suppressed experimentally-induced choroidal neovascularization.

    Directory of Open Access Journals (Sweden)

    Hideyuki Onami

    Full Text Available We established a sustained vasohibin-1 (a 42-kDa protein, delivery device by a novel method using photopolymerization of a mixture of polyethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and collagen microparticles. We evaluated its effects in a model of rat laser-induced choroidal neovascularization (CNV using a transscleral approach. We used variable concentrations of vasohibin-1 in the devices, and used an enzyme-linked immunosorbent assay and Western blotting to measure the released vasohibin-1 (0.31 nM/day when using the 10 μM vasohibin-1 delivery device [10VDD]. The released vasohibin-1 showed suppression activity comparable to native effects when evaluated using endothelial tube formation. We also used pelletized vasohibin-1 and fluorescein isothiocyanate-labeled 40 kDa dextran as controls. Strong fluorescein staining was observed on the sclera when the device was used for drug delivery, whereas pellet use produced strong staining in the conjunctiva and surrounding tissue, but not on the sclera. Vasohibin-1 was found in the sclera, choroid, retinal pigment epithelium (RPE, and neural retina after device implantation. Stronger immunoreactivity at the RPE and ganglion cell layers was observed than in other retinal regions. Significantly lower fluorescein angiography (FA scores and smaller CNV areas in the flat mounts of RPE-choroid-sclera were observed for the 10VDD, VDD (1 μM vasohibin-1 delivery device, and vasohibin-1 intravitreal direct injection (0.24 μM groups when compared to the pellet, non-vasohibin-1 delivery device, and intravitreal vehicle injection groups. Choroidal neovascularization can be treated with transscleral sustained protein delivery using our novel device. We offer a safer sustained protein release for treatment of retinal disease using the transscleral approach.

  2. Sustained zero-order delivery of GC-1 from a nanochannel membrane device alleviates metabolic syndrome.

    Science.gov (United States)

    Filgueira, C S; Nicolov, E; Hood, R L; Ballerini, A; Garcia-Huidobro, J; Lin, J Z; Fraga, D; Webb, P; Sabek, O M; Gaber, A O; Phillips, K J; Grattoni, A

    2016-11-01

    Our objective was to assess the sustained, low-dose and constant administration of the thyroid receptor-β (TRβ)-selective agonist GC-1 (sobetirome) from a novel nanochannel membrane device (NMD) for drug delivery. As it known to speed up metabolism, accomplish weight loss, improve cholesterol levels and possess anti-diabetic effects, GC-1 was steadily administered by our NMD, consisting of an implantable nanochannel membrane, as an alternative to conventional daily administration, which is subject to compliance issues in clinical settings. Diet-induced obese C57BL/J6 male mice were fed a very high-fat diet (VHFD) and received NMD implants subcutaneously. Ten mice per group received capsules containing GC-1 or phosphate-buffered saline (control). Weight, lean and fat mass, as well as cholesterol, triglycerides, insulin and glucose, were monitored for 24 days. After treatment, plasma levels of thyroid-stimulating hormone (TSH) and thyroxine were compared. mRNA levels of a panel of thermogenic markers were examined using real-time PCR in white adipose tissue (WAT) and brown adipose tissue (BAT). Adipose tissue, liver and local inflammatory response to the implant were examined histologically. Pancreatic islet number and β-cell area were assessed. GC-1 released from the NMD reversed VHFD-induced obesity and normalized serum cholesterol and glycemia. Significant reductions in body weight and fat mass were observed within 10 days, whereas reductions in serum cholesterol and glucose levels were seen within 7 days. The significant decrease in TSH was consistent with TRβ selectivity for GC-1. Levels of transcript for Ucp1 and thermogenic genes PGC1a, Cidea, Dio2 and Cox5a showed significant upregulation in WAT in NMD-GC-1-treated mice, but decreased in BAT. Although mice treated by NMD-GC-1 showed a similar number of pancreatic islets, they exhibited significant increase in β-cell area. Our data demonstrate that the NMD implant achieves steady administration of GC-1

  3. A Medical Delivery Device

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a medical delivery device comprising at least two membrane electrode assembly units each of which comprises three layers: an upper and a lower electrode and a selective ionic conductive membrane provided there-between. At least one of the three layers are shared...

  4. Drug delivery device including electrolytic pump

    KAUST Repository

    Foulds, Ian G.

    2016-03-31

    Systems and methods are provided for a drug delivery device and use of the device for drug delivery. In various aspects, the drug delivery device combines a “solid drug in reservoir” (SDR) system with an electrolytic pump. In various aspects an improved electrolytic pump is provided including, in particular, an improved electrolytic pump for use with a drug delivery device, for example an implantable drug delivery device. A catalytic reformer can be incorporated in a periodically pulsed electrolytic pump to provide stable pumping performance and reduced actuation cycle.

  5. MEMS devices for drug delivery.

    Science.gov (United States)

    Lee, Hyunjoo J; Choi, Nakwon; Yoon, Eui-Sung; Cho, Il-Joo

    2017-11-05

    Novel drug delivery systems based on microtechnology have advanced tremendously, but yet face some technological and societal hurdles to fully achieve their potential. The novel drug delivery systems aim to deliver drugs in a spatiotemporal- and dosage-controlled manner with a goal to address the unmet medical needs from oral delivery and hypodermic injection. The unmet needs include effective delivery of new types of drug candidates that are otherwise insoluble and unstable, targeted delivery to areas protected by barriers (e.g. brain and posterior eye segment), localized delivery of potent drugs, and improved patient compliance. After scrutinizing the design considerations and challenges associated with delivery to areas that cannot be efficiently targeted through standard drug delivery (e.g. brain, posterior eye segment, and gastrointestinal tract), this review provides a summary of recent advances that addressed these challenges and summarizes yet unresolved problems in each target area. The opportunities for innovation in devising the novel drug delivery systems are still high; with integration of advanced microtechnology, advanced fabrication of biomaterials, and biotechnology, the novel drug delivery is poised to be a promising alternative to the oral administration and hypodermic injection for a large spectrum of drug candidates. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Sustained delivery of commensal bacteria from pod-intravaginal rings.

    Science.gov (United States)

    Gunawardana, Manjula; Mullen, Madeline; Yoo, Jennifer; Webster, Paul; Moss, John A; Baum, Marc M

    2014-01-01

    Topical administration of live commensal bacteria to the vaginal tract holds significant potential as a cost-effective strategy for the treatment of sexually transmitted infections and the delivery of mucosal vaccines. Probiotic-releasing intravaginal rings (IVRs) embody significant theoretical advantages over traditional daily-dosage forms, such as sustained and controlled delivery leading to improved adherence to therapy compared to that of frequent dosing. The conventional IVR designs, however, are not amenable to the delivery of live bacteria. We have developed a novel pod-IVR technology where polymer-coated tablets ("pods") of Lactobacillus gasseri strain ATCC 33323, a commensal microorganism of human origin, are embedded in silicone IVRs. The release rate of bacterial cells is controlled by the diameter of a delivery channel that exposes a portion of the pod to external fluids. In vitro studies demonstrated that the prototype devices released between 1.1×10(7) and 14×10(7) cells per day for up to 21 days in a controlled sustained fashion with stable burst-free release kinetics. The daily release rates were correlated with the cross-sectional area of the delivery channel. Bacteria in the IVR pods remained viable throughout the in vitro studies and formed biofilms on the surfaces of the devices. This proof-of-principle study represents the first demonstration of a prolonged, sustained release of bacteria from an intravaginal device and warrants further investigation of this device as a nonchemotherapeutic agent for the restoration and maintenance of normal urogenital flora.

  7. Device-assisted transdermal drug delivery.

    Science.gov (United States)

    Lee, Hyunjae; Song, Changyeong; Baik, Seungmin; Kim, Dokyoon; Hyeon, Taeghwan; Kim, Dae-Hyeong

    2017-09-01

    Transdermal drug delivery is a prospective drug delivery strategy to complement the limitations of conventional drug delivery systems including oral and injectable methods. This delivery route allows both convenient and painless drug delivery and a sustained release profile with reduced side effects. However, physiological barriers in the skin undermine the delivery efficiency of conventional patches, limiting drug candidates to small-molecules and lipophilic drugs. Recently, transdermal drug delivery technology has advanced from unsophisticated methods simply relying on natural diffusion to drug releasing systems that dynamically respond to external stimuli. Furthermore, physical barriers in the skin have been overcome using microneedles, and controlled delivery by wearable biosensors has been enabled ultimately. In this review, we classify the evolution of advanced drug delivery strategies based on generations and provide a comprehensive overview. Finally, the recent progress in advanced diagnosis and therapy through customized drug delivery systems based on real-time analysis of physiological cues is highlighted. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A pulsed mode electrolytic drug delivery device

    KAUST Repository

    Yi, Ying

    2015-09-14

    This paper reports the design of a proof-of-concept drug delivery device that is actuated using the bubbles formed during electrolysis. The device uses a platinum (Pt) coated nickel (Ni) metal foam and a solid drug in reservoir (SDR) approach to improve the device\\'s performance. This electrochemically-driven pump has many features that are unlike conventional drug delivery devices: it is capable of pumping periodically and being refilled automatically; it features drug release control; and it enables targeted delivery. Pt-coated metal foam is used as a catalytic reforming element, which reduces the period of each delivery cycle. Two methods were used for fabricating the Pt-coated metal: sputtering and electroplating. Of these two methods, the sputtered Pt-coated metal foam has a higher pumping rate; it also has a comparable recombination rate when compared to the electroplated Pt-coated metal foam. The only drawback of this catalytic reformer is that it consumes nickel scaffold. Considering long-term applications, the electroplated Pt metal foam was selected for drug delivery, where a controlled drug release rate of 2.2 μg ± 0.3 μg per actuation pulse was achieved using 4 mW of power.

  9. Chitosan microneedle patches for sustained transdermal delivery of macromolecules.

    Science.gov (United States)

    Chen, Mei-Chin; Ling, Ming-Hung; Lai, Kuan-Ying; Pramudityo, Esar

    2012-12-10

    This paper introduces a chitosan microneedle patch for efficient and sustained transdermal delivery of hydrophilic macromolecules. Chitosan microneedles have sufficient mechanical strength to be inserted in vitro into porcine skin at approximately 250 μm in depth and in vivo into rat skin at approximately 200 μm in depth. Bovine serum albumin (BSA, MW=66.5 kDa) was used as a model protein to explore the potential use of chitosan microneedles as a transdermal delivery device for protein drugs. In vitro drug release showed that chitosan microneedles can provide a sustained release of BSA for at least 8 days (approximately 95% of drugs released in 8 days). When the Alexa Fluor 488-labeled BSA (Alexa 488-BSA)-loaded microneedles were applied to the rat skin in vivo, confocal microscopic images showed that BSA can gradually diffuse from the puncture sites to the dermal layer and the fluorescence of Alexa 488-BSA can be observed at the depth of 300 μm. In addition, encapsulation of BSA within the microneedle matrix did not alter the secondary structure of BSA, indicating that the gentle nature of the fabrication process allowed for encapsulation of fragile biomolecules. These results suggested that the developed chitosan microneedles may serve as a promising device for transdermal delivery of macromolecules in a sustained manner.

  10. Inhalation drug delivery devices: technology update

    Directory of Open Access Journals (Sweden)

    Ibrahim M

    2015-02-01

    Full Text Available Mariam Ibrahim, Rahul Verma, Lucila Garcia-ContrerasDepartment of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USAAbstract: The pulmonary route of administration has proven to be effective in local and systemic delivery of miscellaneous drugs and biopharmaceuticals to treat pulmonary and non-pulmonary diseases. A successful pulmonary administration requires a harmonic interaction between the drug formulation, the inhaler device, and the patient. However, the biggest single problem that accounts for the lack of desired effect or adverse outcomes is the incorrect use of the device due to lack of training in how to use the device or how to coordinate actuation and aerosol inhalation. This review summarizes the structural and mechanical features of aerosol delivery devices with respect to mechanisms of aerosol generation, their use with different formulations, and their advantages and limitations. A technological update of the current state-of-the-art designs proposed to overcome current challenges of existing devices is also provided.Keywords: pulmonary delivery, asthma, nebulizers, metered dose inhaler, dry powder inhaler

  11. A cyclically actuated electrolytic drug delivery device

    KAUST Repository

    Yi, Ying

    2015-01-01

    This work, focusing on an implantable drug delivery system, presents the first prototype electrolytic pump that combines a catalytic reformer and a cyclically actuated mode. These features improve the release performance and extend the lifetime of the device. Using our platinum (Pt)-coated carbon fiber mesh that acts as a catalytic reforming element, the cyclical mode is improved because the faster recombination rate allows for a shorter cycling time for drug delivery. Another feature of our device is that it uses a solid-drug-in-reservoir (SDR) approach, which allows small amounts of a solid drug to be dissolved in human fluid, forming a reproducible drug solution for long-term therapies. We have conducted proof-of-principle drug delivery studies using such an electrolytic pump and solvent blue 38 as the drug substitute. These tests demonstrate power-controlled and pulsatile release profiles of the chemical substance, as well as the feasibility of this device. A drug delivery rate of 11.44 ± 0.56 μg min-1 was achieved by using an input power of 4 mW for multiple pulses, which indicates the stability of our system. © The Royal Society of Chemistry 2015.

  12. Micromechanical devices for intravascular drug delivery.

    Science.gov (United States)

    Reed, M L; Wu, C; Kneller, J; Watkins, S; Vorp, D A; Nadeem, A; Weiss, L E; Rebello, K; Mescher, M; Smith, A J; Rosenblum, W; Feldman, M D

    1998-11-01

    Microfabrication technology, more commonly applied to the manufacture of integrated circuits, can be used to build devices useful for mechanical delivery of drugs and genes. Microprobes fabricated using silicon micromachining have been used to deliver DNA into cells as an alternative to bombardment and microinjection. This idea can be extended to intravascular stents with integrated microprobes capable of piercing compressed plaque and delivering anti-restenosis therapies into coronary arteries. Preliminary experiments using filleted rabbit arteries have demonstrated transection of the internal elastic lamina. New nonplanar microfabrication technologies are necessary for creating practical devices with cylindrical symmetry; a promising possibility is to use microfabricated structures of anodic metal oxides.

  13. Critical Assessment of Implantable Drug Delivery Devices in Glaucoma Management

    Directory of Open Access Journals (Sweden)

    Dharani Manickavasagam

    2013-01-01

    Full Text Available Glaucoma is a group of heterogeneous disorders involving progressive optic neuropathy that can culminate into visual impairment and irreversible blindness. Effective therapeutic interventions must address underlying vulnerability of retinal ganglion cells (RGCs to degeneration in conjunction with correcting other associated risk factors (such as elevated intraocular pressure. However, realization of therapeutic outcomes is heavily dependent on suitable delivery system that can overcome myriads of anatomical and physiological barriers to intraocular drug delivery. Development of clinically viable sustained release systems in glaucoma is a widely recognized unmet need. In this regard, implantable delivery systems may relieve the burden of chronic drug administration while potentially ensuring high intraocular drug bioavailability. Presently there are no FDA-approved implantable drug delivery devices for glaucoma even though there are several ongoing clinical studies. The paper critically assessed the prospects of polymeric implantable delivery systems in glaucoma while identifying factors that can dictate (a patient tolerability and acceptance, (b drug stability and drug release profiles, (c therapeutic efficacy, and (d toxicity and biocompatibility. The information gathered could be useful in future research and development efforts on implantable delivery systems in glaucoma.

  14. The impact of wireless device access on content delivery networks

    OpenAIRE

    Denney, Justin; Race, Nicholas

    2003-01-01

    Content delivery network architectures are initiatives designed to support the effective delivery of continuous and discrete media to end-users. Mobile devices are now capable of exploiting services such as content delivery, but with the protocols governing the content delivery networks designed for wired networked topologies; an assessment of the impact of mobile devices on the network has never been undertaken. Wireless devices access causes significant issues in the ability of the media tr...

  15. Sustained inflations: comparing three neonatal resuscitation devices.

    Science.gov (United States)

    Klingenberg, Claus; Dawson, Jennifer A; Gerber, Angela; Kamlin, C Omar F; Davis, Peter G; Morley, Colin J

    2011-01-01

    Some national resuscitation guidelines advocate using sustained initial inflations (2-3 s) for babies requiring resuscitation. Inflation times ≥10 s have been used for preterm infants. This study examines the ability of operators of varying experience to provide a sustained inflation using three different manual ventilation devices. We compared a self-inflating bag, a flow-inflating bag and a pressure-limited T-piece device. Fifty clinical staff members from five professional groups gave a sustained inflation with a target peak pressure of 30 cm H2O and target duration of 10 s to an internal leak-free manikin. We measured peak inflating pressure (PIP) and mean inflating pressure (MIP) during the sustained inflation, and the duration of inflating pressure (IP) >20 and 25 cm H2O. Median (IQR) duration of IP >25 cm H2O was: self-inflating bag 2.5 s (0.8-5.7), flow-inflating bag 10.6 s (8.4-12.9) and the T-piece 10.7 s (8.9-11.9). There was a weak correlation between experience using a self-inflating bag and longer inflation times (R = 0.290, p = 0.041). When compared with the T-piece, the flow-inflating bag had lower mean MIP (27.0 ± 1.8 vs. 28.8 ± 2.0 cm H2O) and higher mean PIP (32.3 ± 3.7 vs. 29.8 ± 1.8 cm H2O). There were no differences in performance between operator groups. The T-piece provided consistent PIP during a single 10 s sustained inflation with less variation in pressure compared with the flow-inflating bag. Sustained inflations >3 s were difficult to achieve with a self-inflating bag. Copyright © 2011 S. Karger AG, Basel.

  16. Patient experience with a new teriparatide delivery device.

    Science.gov (United States)

    Dore, Robin K; Feldman, Robert G; Taylor, Kathleen A; See, Kyoungah; Dalsky, Gail P; Warner, Margaret R

    2009-10-01

    To determine functionality and acceptability of a new teriparatide (Forteo, Eli Lilly and Company, Indianapolis, IN, USA) delivery device by patients with osteoporosis. This was an eight week, single-arm, multicenter, open-label clinical trial. Patients received teriparatide 20 microg/day by subcutaneous injection using a new delivery device. Men and postmenopausal women with osteoporosis at high risk for fracture were stratified to Current User (n = 92) or Not Current User (n = 107) groups. Current Users had used the original delivery device for > or =8 weeks, including uninterrupted use for four weeks before enrollment. ClinicalTrials.gov, NCT00577863. The primary objective was to detect common complaints (> or =3% for all patients) regarding the functionality and acceptability of the new device. Complaints were categorized as functional (e.g., malfunction), nonfunctional (e.g., size), or user manual. Secondary objectives included questionnaire assessment of preference of the new versus original device, features of the new delivery device, and analysis of adverse events. A total of 31 patients (16%) reported 47 complaints (four functional, 27 nonfunctional, and 16 user manual). There were two common complaints: device size (4.0%) and lack of information on alcohol swabs (3.5%). Overall, patients agreed that the new device was easy to use (99.5%), easy to learn to use (99%), easy to attach a needle (97%), easy to hold while injecting (95%), and that it reduced their reluctance to take injections (90%). Most Current Users (92%) preferred the new delivery device over the original device. Adverse events reported by > or =2% of patients were upper respiratory infection (3.5%), urinary tract infection (2%), influenza (2%), and headache (2%). Limitations include the one-arm study design and the short (eight week) duration of the study. Patients found the new teriparatide delivery device easy to use and Current Users preferred the new delivery device over the original

  17. On the sustainability area as a simplifying didactic device

    DEFF Research Database (Denmark)

    Harck, Søren H.

    2000-01-01

    Recently, the sustainability area of public finance has been launched as a simplifying screening device for the analysis of fiscal sustainability. In this paper it is argued that the novel notion of the sustainability area (reflecting, in turn, a simple notion of public debt sustainability) does ...

  18. Benchmarking Sustainability Practices Use throughout Industrial Construction Project Delivery

    Directory of Open Access Journals (Sweden)

    Sungmin Yun

    2017-06-01

    Full Text Available Despite the efforts for sustainability studies in building and infrastructure construction, the sustainability issues in industrial construction remain understudied. Further, few studies evaluate sustainability and benchmark sustainability issues in industrial construction from a management perspective. This study presents a phase-based benchmarking framework for evaluating sustainability practices use focusing on industrial facilities project. Based on the framework, this study quantifies and assesses sustainability practices use, and further sorts the results by project phase and major project characteristics, including project type, project nature, and project delivery method. The results show that sustainability practices were implemented higher in the construction and startup phases relative to other phases, with a very broad range. An assessment by project type and project nature showed significant differences in sustainability practices use, but no significant difference in practices use by project delivery method. This study contributes to providing a benchmarking method for sustainability practices in industrial facilities projects at the project phase level. This study also discusses and provides an application of phase-based benchmarking for sustainability in industrial construction.

  19. Generation and delivery device for ozone gas

    Science.gov (United States)

    Andrews, Craig C. (Inventor); Murphy, Oliver J. (Inventor)

    2002-01-01

    The present invention provides an ozone generation and delivery system that lends itself to small scale applications and requires very low maintenance. The system preferably includes an anode reservoir and a cathode phase separator each having a hydrophobic membrane to allow phase separation of produced gases from water. The hydrogen gas, ozone gas and water containing ozone may be delivered under pressure.

  20. Inhaled Drug Delivery: A Practical Guide to Prescribing Inhaler Devices

    Directory of Open Access Journals (Sweden)

    Pierre Ernst

    1998-01-01

    Full Text Available Direct delivery of medication to the target organ results in a high ratio of local to systemic bioavailability and has made aerosol delivery of respiratory medication the route of choice for the treatment of obstructive lung diseases. The most commonly prescribed device is the pressurized metered dose inhaler (pMDI; its major drawback is the requirement that inspiration and actuation of the device be well coordinated. Other requirements for effective drug delivery include an optimal inspiratory flow, a full inspiration from functional residual capacity and a breath hold of at least 6 s. Available pMDIs are to be gradually phased out due to their use of atmospheric ozone-depleting chlorofluorocarbons (CFCs as propellants. Newer pMDI devices using non-CFC propellants are available; preliminary experience suggests these devices greatly increase systemic bioavailability of inhaled corticosteroids. The newer multidose dry powder inhalation devices (DPIs are breath actuated, thus facilitating coordination with inspiration, and contain fewer ingredients. Furthermore, drug delivery is adequate even at low inspired flows, making their use appropriate in almost all situations. Equivalence of dosing among different devices for inhaled corticosteroids will remain imprecise, requiring the physician to adjust the dose of medication to the lowest dose that provides adequate control of asthma. Asthma education will be needed to instruct patients on the effective use of the numerous inhalation devices available.

  1. Design of an Implantable Device for Ocular Drug Delivery

    Directory of Open Access Journals (Sweden)

    Jae-Hwan Lee

    2012-01-01

    Full Text Available Ocular diseases, such as, glaucoma, age-related macular degeneration (AMD, diabetic retinopathy, and retinitis pigmentosa require drug management in order to prevent blindness and affecting million of adults in USA and worldwide. There is an increasing need to develop devices for drug delivery to address ocular diseases. This study focuses on the design, simulation, and development of an implantable ocular drug delivery device consisting of micro-/nanochannels embedded between top and bottom covers with a drug reservoir made from polydimethylsiloxane (PDMS which is silicon-based organic and biodegradable polymer. Several simulations were carried out with six different micro-channel configurations in order to see the feasibility for ocular drug delivery applications. Based on the results obtained, channel design of osmotic I and osmotic II satisfied the diffusion rates required for ocular drug delivery. Finally, a prototype illustrating the three components of the drug delivery design is presented. In the future, the device will be tested for its functionality and diffusion characteristics.

  2. Surgical suture assembled with polymeric drug-delivery sheet for sustained, local pain relief.

    Science.gov (United States)

    Lee, Ji Eun; Park, Subin; Park, Min; Kim, Myung Hun; Park, Chun Gwon; Lee, Seung Ho; Choi, Sung Yoon; Kim, Byung Hwi; Park, Hyo Jin; Park, Ji-Ho; Heo, Chan Yeong; Choy, Young Bin

    2013-09-01

    Surgical suture is a strand of biocompatible material designed for wound closure, and therefore can be a medical device potentially suitable for local drug delivery to treat pain at the surgical site. However, the preparation methods previously introduced for drug-delivery sutures adversely influenced the mechanical strength of the suture itself - strength that is essential for successful wound closure. Thus, it is not easy to control drug delivery with sutures, and the drug-delivery surgical sutures available for clinical use are now limited to anti-infection roles. Here, we demonstrate a surgical suture enabled to provide controlled delivery of a pain-relief drug and, more importantly, we demonstrate how it can be fabricated to maintain the mechanical strength of the suture itself. For this purpose, we separately prepare a drug-delivery sheet composed of a biocompatible polymer and a pain-relief drug, which is then physically assembled with a type of surgical suture that is already in clinical use. In this way, the drug release profiles can be tailored for the period of therapeutic need by modifying only the drug-loaded polymer sheet without adversely influencing the mechanical strength of the suture. The drug-delivery sutures in this work can effectively relieve the pain at the surgical site in a sustained manner during the period of wound healing, while showing biocompatibility and mechanical properties comparable to those of the original surgical suture in clinical use. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Self-tracking devices and sustainable employability : 22 oktober 2015

    NARCIS (Netherlands)

    Dr. Martijn de Groot; Dr. Hilbrand Oldenhuis; Dr. Hugo Velthuijsen; Dr. Louis Polstra

    2015-01-01

    Employees’ level of sustainable employability is influenced by their health. In our study we tested whether self-tracking devicesdevices that provide the user with reliable and continuous feedback on one or more health domains – can be useful tools in order to increase employees’ health and, as a

  4. Towards sustainable design for single-use medical devices.

    Science.gov (United States)

    Hanson, Jacob J; Hitchcock, Robert W

    2009-01-01

    Despite their sophistication and value, single-use medical devices have become commodity items in the developed world. Cheap raw materials along with large scale manufacturing and distribution processes have combined to make many medical devices more expensive to resterilize, package and restock than to simply discard. This practice is not sustainable or scalable on a global basis. As the petrochemicals that provide raw materials become more expensive and the global reach of these devices continues into rapidly developing economies, there is a need for device designs that take into account the total life-cycle of these products, minimize the amount of non-renewable materials consumed and consider alternative hybrid reusable / disposable approaches. In this paper, we describe a methodology to perform life cycle and functional analyses to create additional design requirements for medical devices. These types of sustainable approaches can move the medical device industry even closer to the "triple bottom line"--people, planet, profit.

  5. Reproductive system behavior following exposure of sustained delivery of npy antagonist in ovariectomized (ovx) rats.

    Science.gov (United States)

    Cason, Zelma; Wilson, Gerri; Golanov, Olga; Tucci, Michelle; McGuire, Robert; Benghuzzi, Hamed

    2012-01-01

    Several investigations have documented that sustained delivery of estrogen can modulate or sustain normal female reproductive functions. However, the literature is lacking scientific evidence regarding the mechanism of estrogen and neuropeptide Y antagonist (NPY) effect on the hypothalamic-pituitary-gonadal axis. The objective of this study was to explore the role of sustained delivery of estrogen and its effects on reproductive unction compared to an antagonist such as NPY. A total of twenty adult female rats (OVX, n=15; intact control, n=5) were divided into five groups (intact control, OVX, sham, OVX + estrogen, and OVX + NPY). Animals in two groups were surgically implanted with a TCP delivery device loaded with estrogen or NPY. Vaginal smears and body weights (BW) were evaluated at baseline and at two weeks post implantation. At the end of two weeks, all animals were euthanized and vital and reproductive organs were retrieved for histopathological evaluation. The results revealed differences in BW between intact control and OVX animals. Furthermore, there was statistical difference (P<0.05) in BW between OVX and OVX + NPY animals. Vaginal smear evaluation revealed that estrogen exposure induced estrus cyclic activities as compared to OVX and sham animals. The animals exposed to sustained delivery of NPY triggered moderate cyclic activities compared to intact control animals. There were no significant differences (P<0.5) in vital organ wet weights among and between animals in all groups. Overall this study proved the capability of TCP to release estrogen and NPY at sustained levels, which resulted inpathophysiological changes in female reproductive organs.

  6. Chitosan nanoparticle based delivery systems for sustainable agriculture.

    Science.gov (United States)

    Kashyap, Prem Lal; Xiang, Xu; Heiden, Patricia

    2015-01-01

    Development of technologies that improve food productivity without any adverse impact on the ecosystem is the need of hour. In this context, development of controlled delivery systems for slow and sustained release of agrochemicals or genetic materials is crucial. Chitosan has emerged as a valuable carrier for controlled delivery of agrochemicals and genetic materials because of its proven biocompatibility, biodegradability, non-toxicity, and adsorption abilities. The major advantages of encapsulating agrochemicals and genetic material in a chitosan matrix include its ability to function as a protective reservoir for the active ingredients, protecting the ingredients from the surrounding environment while they are in the chitosan domain, and then controlling their release, allowing them to serve as efficient gene delivery systems for plant transformation or controlled release of pesticides. Despite the great progress in the use of chitosan in the area of medical and pharmaceutical sciences, there is still a wide knowledge gap regarding the potential application of chitosan for encapsulation of active ingredients in agriculture. Hence, the present article describes the current status of chitosan nanoparticle-based delivery systems in agriculture, and to highlight challenges that need to be overcome. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. A Device-to-Device Multicast Scheme for Delay-Constraint Content Delivery

    Directory of Open Access Journals (Sweden)

    Yanli Xu

    2017-01-01

    Full Text Available Motivated by the explosive increase of mobile traffic, study on the device-to-device (D2D communication is kicked off for content delivery through proximal transmission among users. D2D multicast has advantage on serving multiple users simultaneously with less resource cost. However, when D2D multicast is appropriate for content delivery and how to make it serve delay-constraint traffic are still unclear. In this paper, parameters impacting on D2D multicast content delivery is investigated to find good chances for utilizing D2D multicast. Furthermore, some rules to be obeyed are proposed for the content caching and delivery of D2D multicast to satisfy delay constraints. Based on these analyses, a delay-aware multicast scheme is proposed to maximize the network performance utility while satisfying delay constraints of contents. Simulations results verify our analyses and show that the proposed scheme can significantly improve multicast efficiency with guaranteed delay.

  8. Materials to clinical devices: technologies for remotely triggered drug delivery.

    Science.gov (United States)

    Timko, Brian P; Kohane, Daniel S

    2012-11-01

    Technologies in which a remote trigger is used to release drug from an implanted or injected device could enable on-demand release profiles that enhance therapeutic effectiveness or reduce systemic toxicity. A number of new materials have been developed that exhibit sensitivity to light, ultrasound, or electrical or magnetic fields. Delivery systems that incorporate these materials might be triggered externally by the patient, parent or physician to provide flexible control of dose magnitude and timing. To review injectable or implantable systems that are candidates for translation to the clinic, or ones that have already undergone clinical trials. Also considered are applicability in pediatrics and prospects for the future of drug delivery systems. We performed literature searches of the PubMed and Science Citation Index databases for articles in English that reported triggerable drug delivery devices, and for articles reporting related materials and concepts. Approaches to remotely-triggered systems that have clinical potential were identified. Ideally, these systems have been engineered to exhibit controlled on-state release kinetics, low baseline leak rates, and reproducible dosing across multiple cycles. Advances in remotely-triggered drug delivery have been brought about by the convergence of numerous scientific and engineering disciplines, and this convergence is likely to play an important part in the current trend to develop systems that provide more than one therapeutic modality. Preclinical systems must be carefully assessed for biocompatibility, and engineered to ensure pharmacokinetics within the therapeutic window. Future drug delivery systems may incorporate additional modalities, such as closed-loop sensing or onboard power generation, enabling more sophisticated drug delivery regimens. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

  9. Sustained Delivery of Chondroitinase ABC from Hydrogel System

    Directory of Open Access Journals (Sweden)

    Filippo Rossi

    2012-03-01

    Full Text Available In the injured spinal cord, chondroitin sulfate proteoglycans (CSPGs are the principal responsible of axon growth inhibition and they contribute to regenerative failure, promoting glial scar formation. Chondroitinase ABC (chABC is known for being able to digest proteoglycans, thus degrading glial scar and favoring axonal regrowth. However, its classic administration is invasive, infection-prone and clinically problematic. An agarose-carbomer (AC1 hydrogel, already used in SCI repair strategies, was here investigated as a delivery system capable of an effective chABC administration: the material ability to include chABC within its pores and the possibility to be injected into the target tissue were firstly proved. Subsequently, release kinetic and the maintenance of enzymatic activity were positively assessed: AC1 hydrogel was thus confirmed to be a feasible tool for chABC delivery and a promising device for spinal cord injury topic repair strategies.

  10. Medicine Delivery Device with Integrated Sterilization and Detection

    Science.gov (United States)

    Shearn, Michael J.; Greer, Harold F.; Manohara, Harish

    2013-01-01

    Sterile delivery devices can be created by integrating a medicine delivery instrument with surfaces that are coated with germicidal and anti-fouling material. This requires that a large-surface-area template be developed within a constrained volume to ensure good contact between the delivered medicine and the germicidal material. Both of these can be integrated using JPL-developed silicon nanotip or cryo-etch black silicon technologies with atomic layer deposition (ALD) coating of specific germicidal layers. The application of semiconductor processing techniques and technologies to the problems of fluid manipulation and delivery has enabled the integration of chemical, electrical, and mechanical manipulation of samples all within a single microfluidic device. This approach has been successfully applied at JPL to the automated processing, detection, and analysis of minute quantities (parts per trillion level) of biomaterials to develop instruments for in situ exploration or extraterrestrial bodies. The same nanofabrication techniques that are used to produce a microfluidics device are also capable of synthesizing extremely high-surface-area templates in precise locations, and coating those surfaces with conformal films to manipulate their surface properties. This methodology has been successfully applied at JPL to produce patterned and coated silicon nanotips (also known as black silicon) to manipulate the hydrophilicity of surfaces to direct the spreading of fluids in microdevices. JPL's ALD technique is an ideal method to produce the highly conformal coatings required for this type of application. Certain materials, such as TiO2, have germicidal and anti-fouling properties when they are illuminated with UV light. The proposed delivery device contacts medicine with this high-surface-area black silicon surface coated with a thin-film germicidal deposited conformally with ALD. The coating can also be illuminated with ultraviolet light for the purpose of sterilization

  11. Towards soft robotic devices for site-specific drug delivery.

    Science.gov (United States)

    Alici, Gursel

    2015-01-01

    Considerable research efforts have recently been dedicated to the establishment of various drug delivery systems (DDS) that are mechanical/physical, chemical and biological/molecular DDS. In this paper, we report on the recent advances in site-specific drug delivery (site-specific, controlled, targeted or smart drug delivery are terms used interchangeably in the literature, to mean to transport a drug or a therapeutic agent to a desired location within the body and release it as desired with negligibly small toxicity and side effect compared to classical drug administration means such as peroral, parenteral, transmucosal, topical and inhalation) based on mechanical/physical systems consisting of implantable and robotic drug delivery systems. While we specifically focus on the robotic or autonomous DDS, which can be reprogrammable and provide multiple doses of a drug at a required time and rate, we briefly cover the implanted DDS, which are well-developed relative to the robotic DDS, to highlight the design and performance requirements, and investigate issues associated with the robotic DDS. Critical research issues associated with both DDSs are presented to describe the research challenges ahead of us in order to establish soft robotic devices for clinical and biomedical applications.

  12. Impact of direct drug delivery via gastric access devices.

    Science.gov (United States)

    Kurien, Matthew; Penny, Hugo; Sanders, David S

    2015-03-01

    Gastric access devices such as nasogastric tubes and gastrostomy tubes are increasingly being used in clinical practice to provide both short- and long-term nutrition support therapy. Increasingly these devices are being utilized to help deliver oral medications, where swallowing is impaired. This concomitant administration of medications and enteral formulas could derive potential benefits in regard to time and cost; however, uncertainty exists regarding potential drug and nutrient interactions and the influence this may have on both safety and efficacy. This article provides an overview of the differing gastric access devices used in clinical practice and evaluates the evidence base for using oral medications via these routes. Alternative methods of drug administration are discussed, alongside common drug nutrient interactions and potential complications. Delivering medications via gastric access devices can be performed safely; however, careful consideration needs to be made regarding tube and patient influences, alongside drug-nutrient interactions. Improving practice in this area in the future necessitates enhancement of an evidence base to substantiate the safety of drug delivery via gastric access devices and improvement in education among healthcare professionals about the potential problems.

  13. An Implantable MEMS Drug Delivery Device for Rapid Delivery in Ambulatory Emergency Care

    Science.gov (United States)

    2009-06-01

    vol. 32, pp. 377-379, 2000. I. Singer and H. L. Edmonds, "Head-up tilt testing predicts syncope during ventricular tachycardia in implantable... pulse through it, as has been demonstrated in the past (Maloney, 2005). The limitations of this solution are: the significant increase in current to...H. Brem, M. J. Cima, and R. Langer, "Multi- pulse drug delivery from a resorbable polymeric microchip device," Nature Materials, vol. 2, pp. 767-772

  14. Aerosol delivery devices in the treatment of asthma.

    Science.gov (United States)

    Hess, Dean R

    2008-06-01

    Nebulizers convert solutions or suspensions into aerosols with a particle size that can be inhaled into the lower respiratory tract. There are pneumatic jet nebulizers, ultrasonic nebulizers, and mesh nebulizers. Newer nebulizer designs are breath-enhanced, breath-actuated, or have aerosol-storage bags to minimize aerosol loss during exhalation. Nebulizers can be used with helium-oxygen mixture and can be used for continuous aerosol delivery. Increased attention has recently been paid to issues related to the use of a facemask with a nebulizer. The pressurized metered-dose inhaler (pMDI) is a very commonly used device for aerosol delivery. There are press-and-breathe and breath-actuated pMDI designs. Issues related to pMDIs that have received increasing attention are the conversion to hydrofluoroalkane propellant and the use of dose counters. Many patients have poor pMDI technique. Valved holding chambers and spacers are used to improve pMDI technique and to decrease aerosol deposition in the upper airway. In recent years increasing attention has been paid to the issues of electrostatic charge and facemasks related to valved holding chambers. Many newer formulations for inhalation have been released in dry-powder inhalers, which are either unit-dose or multi-dose inhalers. Systematic reviews and meta-analyses have suggested that each of these aerosol delivery devices can work equally well in patients who can use them correctly. However, many patients use these devices incorrectly, so proper patient education in their use is critical.

  15. Massive clonidine overdose during refill of an implanted drug delivery device for intrathecal analgesia: a review of inadvertent soft-tissue injection during implantable drug delivery device refills and its management.

    Science.gov (United States)

    Johnson, Marlene L; Visser, Eric J; Goucke, C Roger

    2011-07-01

    The study aims to highlight the potentially serious consequences of inadvertent soft-tissue injection of intrathecal drugs such as clonidine, during refills of implanted drug delivery devices, and to suggest strategies to reduce this complication. Case report and literature review were used. We report the case of a 51-year-old female with chronic arm pain who sustained a massive clonidine overdose (18,000 mcg) due to inadvertent soft-tissue injection during a refill of an implanted drug delivery device, resulting in rapid loss of consciousness and significant cardiovascular instability requiring urgent resuscitation, subsequent myocardial infarction, cardiac failure, and other significant complications. The risks of inadvertent soft-tissue injection of intrathecal drugs during implanted drug delivery device refills and management of such events is poorly documented in the literature. Inadvertent soft-tissue injection is possibly an underappreciated and underreported complication of intrathecal analgesia via an implanted drug delivery device. Under some circumstances, large doses of other intrathecal drugs such as bupivacaine, opioids, ziconotide, and baclofen may also be delivered by inadvertent soft-tissue injection with potentially life-threatening consequences. We recommend that practitioners, institutions, and professional bodies who manage patients with intrathecal analgesia via intrathecal drug delivery devices highlight and audit this complication and develop systems to manage it. Wiley Periodicals, Inc.

  16. Ocular Insert: Dosage Form for Sustain Opthalmic Drug Delivery

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2012-06-01

    Full Text Available Except for skin, the eye is the most easily accessible site for topical administration of a medication. Traditional topical ophthalmic formulations (eye drops and ointments have poor bioavailability because of rapid pre-corneal elimination, conjunctival absorption, solution drainage by gravity, induced lacrimation and normal tear turnover. This leads to frequent installations of concentrated medication to achieve a therapeutic effect. The typical “pulse-entry” type drug release observed with ocular aqueous solutions (eye drops, suspensions and ointments can be replaced by more controlled, sustained, and continuous drug delivery, using a controlled-release ocular drug delivery system. Ocular inserts are solid or semisolid sterile preparations, of appropriate size and shape, designed to be inserted behind the eyelid or held on the eye and to deliver drugs for topical or systemic effect. These are polymeric systems into which the drug is incorporated as a solution or dispersion. They are better tolerated as to drainage and tear flow compared with other ophthalmic formulation and produce reliable drug release in the conjunctival cul-de-sac.

  17. Polyelectrolyte microcapsules for sustained delivery of water-soluble drugs

    Energy Technology Data Exchange (ETDEWEB)

    Anandhakumar, S.; Debapriya, M. [Department of Materials Engineering, Indian Institute of Science, Bangalore, 560012 (India); Nagaraja, V. [Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012 (India); Raichur, Ashok M., E-mail: amr@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore, 560012 (India)

    2011-03-12

    Polyelectrolyte capsules composed of weak polyelectrolytes are introduced as a simple and efficient system for spontaneous encapsulation of low molecular weight water-soluble drugs. Polyelectrolyte capsules were prepared by layer-by-layer (LbL) assembling of weak polyelectrolytes, poly(allylamine hydrochloride) (PAH) and poly(methacrylic acid) (PMA) on polystyrene sulfonate (PSS) doped CaCO{sub 3} particles followed by core removal with ethylene-diaminetetraacetic acid (EDTA). The loading process was observed by confocal laser scanning microscopy (CLSM) using tetramethylrhodamineisothiocyanate labeled dextran (TRITC-dextran) as a fluorescent probe. The intensity of fluorescent probe inside the capsule decreased with increase in cross-linking time. Ciprofloxacin hydrochloride (a model water-soluble drug) was spontaneously deposited into PAH/PMA capsules and their morphological changes were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The quantitative study of drug loading was also elucidated which showed that drug loading increased with initial drug concentration, but decreased with increase in pH. The loaded drug was released in a sustained manner for 6 h, which could be further extended by cross-linking the capsule wall. The released drug showed significant antibacterial activity against E. coli. These findings indicate that such capsules can be potential carriers for water-soluble drugs in sustained/controlled drug delivery applications.

  18. Designing and assessing a sustainable networked delivery (SND) system: hybrid business-to-consumer book delivery case study.

    Science.gov (United States)

    Kim, Junbeum; Xu, Ming; Kahhat, Ramzy; Allenby, Braden; Williams, Eric

    2009-01-01

    We attempted to design and assess an example of a sustainable networked delivery (SND) system: a hybrid business-to-consumer book delivery system. This system is intended to reduce costs, achieve significant reductions in energy consumption, and reduce environmental emissions of critical local pollutants and greenhouse gases. The energy consumption and concomitant emissions of this delivery system compared with existing alternative delivery systems were estimated. We found that regarding energy consumption, an emerging hybrid delivery system which is a sustainable networked delivery system (SND) would consume 47 and 7 times less than the traditional networked delivery system (TND) and e-commerce networked delivery system (END). Regarding concomitant emissions, in the case of CO2, the SND system produced 32 and 7 times fewer emissions than the TND and END systems. Also the SND system offer meaningful economic benefit such as the costs of delivery and packaging, to the online retailer, grocery, and consumer. Our research results show that the SND system has a lot of possibilities to save local transportation energy consumption and delivery costs, and reduce environmental emissions in delivery system.

  19. Design and evaluation of chitosan/ethylcellulose mucoadhesive bilayered devices for buccal drug delivery.

    Science.gov (United States)

    Remuñán-López, C; Portero, A; Vila-Jato, J L; Alonso, M J

    1998-11-13

    This paper describes the preparation of new buccal bilayered devices comprising a drug-containing mucoadhesive layer and a drug-free backing layer, by two different methods. Bilaminated films were produced by a casting/solvent evaporation technique and bilayered tablets were obtained by direct compression. The mucoadhesive layer was composed of a mixture of drug and chitosan, with or without an anionic crosslinking polymer (polycarbophil, sodium alginate, gellan gum), and the backing layer was made of ethylcellulose. The double-layered structure design was expected to provide drug delivery in a unidirectional fashion to the mucosa and avoid loss of drug due to wash-out with saliva. Using nifedipine and propranolol hydrochloride as slightly and highly water-soluble model drugs, respectively, it was demonstrated that these new devices show promising potential for use in controlled delivery of drugs to the oral cavity. The uncrosslinked chitosan-containing devices absorbed a large quantity of water, gelled and then eroded, allowing drug release. The bilaminated films showed a sustained drug release in a phosphate buffer (pH 6.4). Furthermore, tablets that displayed controlled swelling and drug release and adequate adhesivity were produced by in situ crosslinking the chitosan with polycarbophil.

  20. Microneedle arrays as medical devices for enhanced transdermal drug delivery.

    Science.gov (United States)

    Garland, Martin J; Migalska, Katarzyna; Mahmood, Tuan Mazlelaa Tuan; Singh, Thakur Raghu Raj; Woolfson, A David; Donnelly, Ryan F

    2011-07-01

    In order to exploit the transdermal route for systemic delivery of a wide range of drug molecules, including peptide/protein molecules and genetic material, a means of disrupting the excellent barrier properties of the uppermost layer of the skin, the stratum corneum, must be sought. The use of microneedle (MN) arrays has been proposed as a method to temporarily disrupt the barrier function of the skin and thus enable enhanced transdermal drug delivery. MN arrays consist of a plurality of micron-sized needles, generally ranging from 25 to 2000 µm in height, of a variety of different shapes and composition (e.g., silicon, metal, sugars and biodegradable polymers). The application of such MN arrays to the skin results in the creation of aqueous channels that are orders of magnitude larger than molecular dimensions and, therefore, should readily permit the transport of macromolecules. This article will focus on recent and future developments for MN technology, focusing on the materials used for MN fabrication, the forces required for MN insertion and potential safety aspects that may be involved with the use of MN devices.

  1. Fibrin sealant as a carrier for sustained delivery of antibiotics

    Directory of Open Access Journals (Sweden)

    Selçuk Kara

    2014-06-01

    Full Text Available Objective: To evaluate the activity and sustained release of antibiotics from fibrin sealant against common strains of ocular bacteria. Methods: Vancomycin, ceftazidime, moxifloxacin and lomefloxacin were incorporated into fibrin sealant in the shape of discs. Each antibiotic disc and control fibrin disc without drug was tested in vitro against standard bacterial strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Pseudomonas aeroginosa. After 24 hours of incubation at 37 °C, the discs were transferred to new plates of bacteria and triplicated for each antibiotic. Results: All antibiotic discs demonstrated detectable activity after 24 hours. Vancomycin had the longest duration of activity (4 days on the S. pneumonia grown plate. The moxifloxacin discs showed a prolonged inhibition of S. aureus and S. pneumonia for 3 days and inhibited the other strains for 2 days. Conclusion: Fibrin sealants provided prolonged drug delivery, which indicates that antibiotic-loaded fibrin clots could be useful for early ocular postoperative care and treatment. J Clin Exp Invest 2014; 5 (2: 194-199

  2. Transdermal delivery devices: fabrication, mechanics and drug release from silk.

    Science.gov (United States)

    Raja, Waseem K; Maccorkle, Scott; Diwan, Izzuddin M; Abdurrob, Abdurrahman; Lu, Jessica; Omenetto, Fiorenzo G; Kaplan, David L

    2013-11-11

    Microneedles are a relatively simple, minimally invasive and painless approach to deliver drugs across the skin. However, there remain limitations with this approach because of the materials most commonly utilized for such systems. Silk protein, with tunable and biocompatibility properties, is a useful biomaterial to overcome the current limitations with microneedles. Silk devices preserve drug activity, offer superior mechanical properties and biocompatibility, can be tuned for biodegradability, and can be processed under aqueous, benign conditions. In the present work, the fabrication of dense microneedle arrays from silk with different drug release kinetics is reported. The mechanical properties of the microneedle patches are tuned by post-fabrication treatments or by loading the needles with silk microparticles, to increase capacity and mechanical strength. Drug release is further enhanced by the encapsulation of the drugs in the silk matrix and coating with a thin dissolvable drug layer. The microneedles are used on human cadaver skin and drugs are delivered successfully. The various attributes demonstrated suggest that silk-based microneedle devices can provide significant benefit as a platform material for transdermal drug delivery. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices.

    Science.gov (United States)

    2010-04-01

    ... life-sustaining devices. 860.93 Section 860.93 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES MEDICAL DEVICE CLASSIFICATION PROCEDURES Classification § 860.93 Classification of implants, life-supporting or life-sustaining devices. (a) The...

  4. NovoPen Echo® insulin delivery device

    Directory of Open Access Journals (Sweden)

    Hyllested-Winge J

    2016-01-01

    Full Text Available Jacob Hyllested-Winge,1 Thomas Sparre,2 Line Kynemund Pedersen2 1Novo Nordisk Pharma Ltd, Tokyo, Japan; 2Novo Nordisk A/S, Søborg, Denmark Abstract: The introduction of insulin pen devices has provided easier, well-tolerated, and more convenient treatment regimens for patients with diabetes mellitus. When compared with vial and syringe regimens, insulin pens offer a greater clinical efficacy, improved quality of life, and increased dosing accuracy, particularly at low doses. The portable and discreet nature of pen devices reduces the burden on the patient, facilitates adherence, and subsequently contributes to the improvement in glycemic control. NovoPen Echo® is one of the latest members of the NovoPen® family that has been specifically designed for the pediatric population and is the first to combine half-unit increment (=0.5 U of insulin dosing with a simple memory function. The half-unit increment dosing amendments and accurate injection of 0.5 U of insulin are particularly beneficial for children (and insulin-sensitive adults/elders, who often require small insulin doses. The memory function can be used to record the time and amount of the last dose, reducing the fear of double dosing or missing a dose. The memory function also provides parents with extra confidence and security that their child is taking insulin at the correct doses and times. NovoPen Echo is a lightweight, durable insulin delivery pen; it is available in two different colors, which may help to distinguish between different types of insulin, providing more confidence for both users and caregivers. Studies have demonstrated a high level of patient satisfaction, with 80% of users preferring NovoPen Echo to other pediatric insulin pens. Keywords: NovoPen Echo®, memory function, half-unit increment dosing, adherence, children, adolescents 

  5. The efficacy of oxygen wafting using different delivery devices, flow rates and device positioning.

    Science.gov (United States)

    Blake, Denise F; Shih, Elizabeth M; Mateos, Paul; Brown, Lawrence H

    2014-08-01

    Oxygen "wafting" provides a non-contact oxygen alternative for uncooperative paediatric patients in the emergency department (ED). The aim of this study was to identify the combination of oxygen delivery device, flow rate and device positioning that delivers the highest concentration of wafted oxygen. ED nursing staff were surveyed to determine current oxygen wafting practice. A simulated patient and oxygen sensor were used to compare wafted oxygen concentrations for six delivery devices in various positions and oxygen flow rates. Only oxygen tubing and the paediatric non-rebreather mask consistently delivered wafted oxygen concentrations above 30%. The paediatric non-rebreather held below the face produced concentrations ranging from 26.1% (10 cm) to 39.8% (5 cm). At 15 L/min, tubing held in front of the face produced concentrations ranging from 31.2% (15 cm) to 56.7% (5 cm); reducing the flow rate to 6-8 L/min had no meaningful effect on the delivered oxygen concentration. When tubing was used below the face, flow rates between 6 and 8 L/min produced somewhat higher concentrations than 15 L/min (5 cm: 36.3% vs. 30.9%). When delivering oxygen by wafting, the highest oxygen concentrations are achieved when positioning tubing 5-15 cm in front of the face or positioning tubing or a paediatric non-rebreather mask 5-10 cm below the face at 10-15 L/min flow. This should be considered when using oxygen wafting in the ED. Copyright © 2014 College of Emergency Nursing Australasia Ltd. Published by Elsevier Ltd. All rights reserved.

  6. Development of polyether urethane intravaginal rings for the sustained delivery of hydroxychloroquine

    Directory of Open Access Journals (Sweden)

    Chen Y

    2014-10-01

    Full Text Available Yufei Chen,1 Yannick Leandre Traore,1 Amanda Li,1 Keith R Fowke,2,3 Emmanuel A Ho1 1Laboratory for Drug Delivery and Biomaterials, Faculty of Pharmacy, 2Department of Medical Microbiology and Infectious Diseases, 3Department of Community Health Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada Abstract: Hydroxychloroquine (HCQ has been shown to demonstrate anti-­inflammatory properties and direct anti-HIV activity. In this study, we describe for the first time the fabrication and in vitro evaluation of two types of intravaginal ring (IVR devices (a surfaced-modified matrix IVR and a reservoir segmental IVR for achieving sustained delivery (>14 days of HCQ as a strategy for preventing male-to-female transmission of HIV. Both IVRs were fabricated by hot-melt injection molding. Surface-modified matrix IVRs with polyvinylpyrrolidone or poly(vinyl alcohol coatings exhibited significantly reduced burst release on the first day (6.45% and 15.72% reduction, respectively. Reservoir IVR segments designed to release lower amounts of HCQ displayed near-zero-order release kinetics with an average release rate of 28.38 µg/mL per day for IVRs loaded with aqueous HCQ and 32.23 µg/mL per day for IVRs loaded with HCQ mixed with a rate-controlling excipient. Stability studies demonstrated that HCQ was stable in coated or noncoated IVRs for 30 days. The IVR segments had no significant effect on cell viability, pro-inflammatory cytokine production, or colony formation of vaginal and ectocervical epithelial cells. Both IVR systems may be suitable for the prevention of HIV transmission and other sexually transmitted infections. Keywords: intravaginal delivery, matrix system, reservoir system, polymeric drug carrier, drug release, microbicide, HIV/AIDS

  7. Sustained-release drug delivery of antimicrobials in controlling of supragingival oral biofilms.

    Science.gov (United States)

    Steinberg, Doron; Friedman, Michael

    2017-04-01

    Dental caries, a bacterial biofilm-associated disease, is a prevalent oral health problem. It is a bacterial biofilm-associated disease. Conventional means of combating this disease involves oral hygiene, mostly tooth brushing. Supplementary means of prevention and treatment is often necessary. The use of sustained-release delivery systems, locally applied to the oral cavity appears to be one of the most acceptable avenues for the delivery of antimicrobial agents. Area covered: The development and current approaches of local sustained delivery technologies applied to the oral cavity for treatment and prevention of dental caries is discussed. The use of polymeric drug delivery systems, varnishes, liposomes and nanoparticles is presented. Expert opinion: The use of local sustained-release delivery systems applied to the oral cavity has numerous clinical, pharmacological and toxicological advantages over conventional means. Various sustained-release technologies have been suggested over the course of several years. The current research on oral diseases concentrates predominantly on improving the drug delivery. With progress in pharmaceutical technology, sophisticated controlled-release platforms are being developed. The sustained release concept is innovative and there are few products available for the benefit of all populations. Harmonizing academic research with the dental industry will surely expedite the development and commercialization of more products of such pharmacological nature.

  8. Chronic, programmed polypeptide delivery from an implanted, multireservoir microchip device.

    Science.gov (United States)

    Prescott, James H; Lipka, Sara; Baldwin, Samuel; Sheppard, Norman F; Maloney, John M; Coppeta, Jonathan; Yomtov, Barry; Staples, Mark A; Santini, John T

    2006-04-01

    Implanted drug delivery systems are being increasingly used to realize the therapeutic potential of peptides and proteins. Here we describe the controlled pulsatile release of the polypeptide leuprolide from microchip implants over 6 months in dogs. Each microchip contains an array of discrete reservoirs from which dose delivery can be controlled by telemetry.

  9. Application of mathematical modeling in sustained release delivery systems.

    Science.gov (United States)

    Grassi, Mario; Grassi, Gabriele

    2014-08-01

    This review, presenting as starting point the concept of the mathematical modeling, is aimed at the physical and mathematical description of the most important mechanisms regulating drug delivery from matrix systems. The precise knowledge of the delivery mechanisms allows us to set up powerful mathematical models which, in turn, are essential for the design and optimization of appropriate drug delivery systems. The fundamental mechanisms for drug delivery from matrices are represented by drug diffusion, matrix swelling, matrix erosion, drug dissolution with possible recrystallization (e.g., as in the case of amorphous and nanocrystalline drugs), initial drug distribution inside the matrix, matrix geometry, matrix size distribution (in the case of spherical matrices of different diameter) and osmotic pressure. Depending on matrix characteristics, the above-reported variables may play a different role in drug delivery; thus the mathematical model needs to be built solely on the most relevant mechanisms of the particular matrix considered. Despite the somewhat diffident behavior of the industrial world, in the light of the most recent findings, we believe that mathematical modeling may have a tremendous potential impact in the pharmaceutical field. We do believe that mathematical modeling will be more and more important in the future especially in the light of the rapid advent of personalized medicine, a novel therapeutic approach intended to treat each single patient instead of the 'average' patient.

  10. Polymeric particles for sustained and local drug delivery

    NARCIS (Netherlands)

    Ramazani, F.

    2015-01-01

    Controlled drug delivery systems have been extensively investigated as means to prolong the action of drugs in the body. In this regard, a drug is incorporated into a carrier (e.g., polymeric material) in such a way that the drug is released from the matrix in a controlled manner for an extended

  11. Perioperative Management of a Patient With an Intrathecal Drug Delivery Device Infusing Ziconotide: A Case Report.

    Science.gov (United States)

    Patel, Sephalie; Hafez, Osama; Sexton, Wade J; Edwards, David A

    2017-02-15

    Intrathecal ziconotide is used for the treatment of chronic pain and is delivered by an implanted drug delivery device. Anesthesiologists should be familiar with the perioperative management of the pump as well as the potential adverse events related to continued ziconotide infusion during general anesthesia. A case is presented demonstrating the perioperative management of an intrathecal drug delivery device infusing ziconotide in a patient presenting for radical cystectomy with pelvic lymphadenectomy and ileal conduit diversion.

  12. Perioperative Management of a Patient With an Intrathecal Drug Delivery Device Infusing Ziconotide.

    Science.gov (United States)

    Patel, Sephalie; Hafez, Osama; Sexton, Wade J; Edwards, David A

    2016-12-09

    Intrathecal ziconotide is used for the treatment of chronic pain and is delivered by an implanted drug delivery device. Anesthesiologists should be familiar with the perioperative management of the pump as well as the potential adverse events related to continued ziconotide infusion during general anesthesia. A case is presented demonstrating the perioperative management of an intrathecal drug delivery device infusing ziconotide in a patient presenting for radical cystectomy with pelvic lymphadenectomy and ileal conduit diversion.

  13. Iontophoretic device delivery for the localized treatment of pancreatic ductal adenocarcinoma

    OpenAIRE

    Byrne, James D.; Jajja, Mohammad R. N.; Schorzman, Allison N.; Keeler, Amanda W.; Luft, J. Christopher; Zamboni, William C.; DeSimone, Joseph M.; Yeh, Jen Jen

    2016-01-01

    Drug delivery to pancreatic tumors is impaired by a unique desmoplastic response and poor tumor vascularization. A drug delivery device capable of overcoming these barriers could provide substantial benefit for patients with pancreatic cancer. In this study, we show that local iontophoretic delivery of folinic acid (leucovorin), fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX) resulted in better tumor response and tolerability compared with i.v. FOLFIRINOX. Given the low systemic exposu...

  14. An in-vivo evaluation of a MEMS drug delivery device using Kunming mice model.

    Science.gov (United States)

    Liu, Yaqian; Song, Peiyi; Liu, Jianwei; Tng, Danny Jian Hang; Hu, Rui; Chen, Hongyan; Hu, Yazhuo; Tan, Cher Heng; Wang, Jianhua; Liu, Jing; Ye, Ling; Yong, Ken-Tye

    2015-02-01

    The use of MEMS implantable drug delivery pump device enables one to program the desired drug delivery profile in the device for individualized medicine treatment to patients. In this study, a MEMS drug delivery device is prepared and employed for in vivo applications. 12 devices are implanted subcutaneously into Kunming mice for evaluating their long term biocompatibility and drug-delivery efficiency in vivo. All the mice survived after device implantation surgery procedures. Histological analysis result reveals a normal wound healing progression within the tissues-to-device contact areas. Serum analysis shows that all measured factors are within normal ranges and do not indicate any adverse responses associated with the implanted device. Phenylephrine formulation is chosen and delivered to the abdominal cavity of the mice by using either the implanted MEMS device (experimental group) or the syringe injection method (control group). Both groups show that they are able to precisely control and manipulate the increment rate of blood pressure in the small animals. Our result strongly suggests that the developed refillable implantable MEMS devices will serve as a viable option for future individualized medicine applications such as glaucoma, HIV-dementia and diabetes therapy.

  15. Vial usage, device dead space, vaccine wastage, and dose accuracy of intradermal delivery devices for inactivated poliovirus vaccine (IPV).

    Science.gov (United States)

    Jarrahian, Courtney; Rein-Weston, Annie; Saxon, Gene; Creelman, Ben; Kachmarik, Greg; Anand, Abhijeet; Zehrung, Darin

    2017-03-27

    Intradermal delivery of a fractional dose of inactivated poliovirus vaccine (IPV) offers potential benefits compared to intramuscular (IM) delivery, including possible cost reductions and easing of IPV supply shortages. Objectives of this study were to assess intradermal delivery devices for dead space, wastage generated by the filling process, dose accuracy, and total number of doses that can be delivered per vial. Devices tested included syringes with staked (fixed) needles (autodisable syringes and syringes used with intradermal adapters), a luer-slip needle and syringe, a mini-needle syringe, a hollow microneedle device, and disposable-syringe jet injectors with their associated filling adapters. Each device was used to withdraw 0.1-mL fractional doses from single-dose IM glass vials which were then ejected into a beaker. Both vial and device were weighed before and after filling and again after expulsion of liquid to record change in volume at each stage of the process. Data were used to calculate the number of doses that could potentially be obtained from multidose vials. Results show wide variability in dead space, dose accuracy, overall wastage, and total number of doses that can be obtained per vial among intradermal delivery devices. Syringes with staked needles had relatively low dead space and low overall wastage, and could achieve a greater number of doses per vial compared to syringes with a detachable luer-slip needle. Of the disposable-syringe jet injectors tested, one was comparable to syringes with staked needles. If intradermal delivery of IPV is introduced, selection of an intradermal delivery device can have a substantial impact on vaccine wasted during administration, and thus on the required quantity of vaccine that needs to be purchased. An ideal intradermal delivery device should be not only safe, reliable, accurate, and acceptable to users and vaccine recipients, but should also have low dead space, high dose accuracy, and low overall

  16. PAIN RELIEF MEDIATED BY IMPLANTABLE DRUG-DELIVERY DEVICES

    NARCIS (Netherlands)

    HOEKSTRA, A

    Various totally implantable drug delivery systems from single access ports to micropumps are now available for administration of repeated boluses, and continuous or programmable infusions. In this respect, emphasis is given to a relatively cheap, totally implantable system for self-administering

  17. Nanoparticles laden in situ gel for sustained ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Himanshu Gupta

    2013-01-01

    Full Text Available Proper availability of drug on to corneal surface is a challenging task. However, due to ocular physiological barriers, conventional eye drops display poor ocular bioavailability of drugs (< 1%. To improve precorneal residence time and ocular penetration, earlier our group developed and evaluated in situ gel and nanoparticles for ocular delivery. In interest to evaluate the combined effect of in situ gel and nanoparticles on ocular retention, we combined them. We are the first to term this combination as "nanoparticle laden in situ gel", that is, poly lactic co glycolic acid nanoparticle incorporated in chitosan in situ gel for sparfloxacin ophthalmic delivery. The formulation was tested for various physicochemical properties. It showed gelation pH near pH 7.2. The observation of acquired gamma camera images showed good retention over the entire precorneal area for sparfloxacin nanoparticle laden in situ gel (SNG as compared to marketed formulation. SNG formulation cleared at a very slow rate and remained at corneal surface for longer duration as no radioactivity was observed in systemic circulation. The developed formulation was found to be better in combination and can go up to the clinical evaluation and application.

  18. Iontophoretic device delivery for the localized treatment of pancreatic ductal adenocarcinoma.

    Science.gov (United States)

    Byrne, James D; Jajja, Mohammad R N; Schorzman, Allison N; Keeler, Amanda W; Luft, J Christopher; Zamboni, William C; DeSimone, Joseph M; Yeh, Jen Jen

    2016-02-23

    Poor delivery and systemic toxicity of many cytotoxic agents, such as the recent promising combination chemotherapy regimen of folinic acid (leucovorin), fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX), restrict their full utility in the treatment of pancreatic cancer. Local delivery of chemotherapies has become possible using iontophoretic devices that are implanted directly onto pancreatic tumors. We have fabricated implantable iontophoretic devices and tested the local iontophoretic delivery of FOLFIRINOX for the treatment of pancreatic cancer in an orthotopic patient-derived xenograft model. Iontophoretic delivery of FOLFIRINOX was found to increase tumor exposure by almost an order of magnitude compared with i.v. delivery with substantially lower plasma concentrations. Mice treated for 7 wk with device FOLFIRINOX experienced significantly greater tumor growth inhibition compared with i.v. FOLFIRINOX. A marker of cell proliferation, Ki-67, was stained, showing a significant reduction in tumor cell proliferation. These data capitalize on the unique ability of an implantable iontophoretic device to deliver much higher concentrations of drug to the tumor compared with i.v. delivery. Local iontophoretic delivery of cytotoxic agents should be considered for the treatment of patients with unresectable nonmetastatic disease and for patients with the need for palliation of local symptoms, and may be considered as a neoadjuvant approach to improve resection rates and outcome in patients with localized and locally advanced pancreatic cancer.

  19. A sustainable and affordable support system for rural healthcare delivery

    CSIR Research Space (South Africa)

    Barjis, J

    2013-12-01

    Full Text Available et al., 2009). Furthermore, many projects that have taken place, started by government or non-government organizations, have delivered ‘white elephants’ rather than a sustainable system. The idiom of ‘white elephant’ (Robinson and Toryik, 2005, p.... The remainder of this paper is structured as follows: in part one we discuss the socio-cultural and economic context, which sets the stage for the research carried out and the results presented in this article; in part we discuss the underlying theoretical...

  20. A Microfluidic Device for Spatiotemporal Delivery of Stimuli to Cells

    Directory of Open Access Journals (Sweden)

    Zubaidah Ningsih

    2015-03-01

    Full Text Available Living cells encounter many stimuli from the immediate environment. Receptors recognize these environmental cues and transduce signals to produce cell responses. The frequency of a signal is now emerging as an important factor determining cell responses. As a componentry system in understanding temporal stimulation, microfluidic devices allow the observation of cell behaviour under dynamic stimulation and controllable environment. In this paper we describe the design, construction and characterization of a microfluidic device suitable for cell stimulation studies.

  1. Sustained delivery of biomolecules from gelatin carriers for applications in bone regeneration.

    Science.gov (United States)

    Song, Jiankang; Leeuwenburgh, Sander Cg

    2014-08-01

    Local delivery of therapeutic biomolecules to stimulate bone regeneration has matured considerably during the past decades, but control over the release of these biomolecules still remains a major challenge. To this end, suitable carriers that allow for tunable spatial and temporal delivery of biomolecules need to be developed. Gelatin is one of the most widely used natural polymers for the controlled and sustained delivery of biomolecules because of its biodegradability, biocompatibility, biosafety and cost-effectiveness. The current study reviews the applications of gelatin as carriers in form of bulk hydrogels, microspheres, nanospheres, colloidal gels and composites for the programmed delivery of commonly used biomolecules for applications in bone regeneration with a specific focus on the relationship between carrier properties and delivery characteristics.

  2. Micro fabrication of biodegradable polymer drug delivery devices

    DEFF Research Database (Denmark)

    Nagstrup, Johan

    permeability and degradation. These systems are for the majority based on traditional materials used in micro technology, such as SU-8, silicon, poly(methyl methacrylate). The next step in developing these new drug delivery systems is to replace classical micro fabrication materials with biodegradable polymers....... In order to successfully do this, methods for fabricating micro structures in biodegradable polymers need to be developed. The goal of this project has been to develop methods for micro fabrication in biodegradable polymers and to use these methods to produce micro systems for oral drug delivery. This has...... successfully been achieved by fabrication of micro container systems made of poly(Llactic acid) and polycaprolactone. To achieve this, polymer solutions have been developed using the theory of Hansen’s solubility parameters. The solutions are used to fabricate polymer films by spin coating, which are used...

  3. Sustainability of Farm Credit Delivery by Cooperatives and NGOs in Edo and Delta States, Nigeria

    Science.gov (United States)

    Alufohai, G. O.

    2006-01-01

    The paper examined the sustainability rates of co-operatives and NGOs in farm credit delivery in Edo and Delta States of Nigeria. The Subsidy Dependence Indices (SDI) and the capital formation rates were determined using both primary and secondary data obtained from 80 and 20 purposively selected cooperatives and NGOs respectively, based on their…

  4. Polymer nanocomposite particles of S-nitrosoglutathione: A suitable formulation for protection and sustained oral delivery.

    Science.gov (United States)

    Wu, Wen; Gaucher, Caroline; Fries, Isabelle; Hu, Xian-ming; Maincent, Philippe; Sapin-Minet, Anne

    2015-11-10

    S-nitrosoglutathione (GSNO) is a nitric oxide (NO) donor with therapeutic potential for cardiovascular disease treatment. Chronic oral treatment with GSNO is limited by high drug sensitivity to the environment and limited oral bioavailability, requiring the development of delivery systems able to sustain NO release. The present work describes new platforms based on polymer nanocomposite particles for the delivery of GSNO. Five types of optimized nanocomposite particles have been developed (three based on chitosan, two based on alginate sodium). Those nanocomposite particles encapsulate GSNO with high efficiency from 64% to 70% and an average size of 13 to 61 μm compatible with oral delivery. Sustained release of GSNO in vitro was achieved. Indeed, chitosan nanocomposites discharged their payload within 24h; whereas alginate nanocomposites released GSNO more slowly (10% of GSNO was still remaining in the dosage form after 24h). Their cytocompatibility toward intestinal Caco-2 cells (MTT assay) was acceptable (IC50: 6.07 ± 0.07-9.46 ± 0.08 mg/mL), demonstrating their suitability as oral delivery systems for GSNO. These delivery systems presented efficient GSNO loading and sustained release as well as cytocompatibility, showing their promise as a means of improving the oral bioavailability of GSNO and as a potential new treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Controlled Release System for Localized and Sustained Drug Delivery Applications

    Science.gov (United States)

    Rodriguez, Lidia Betsabe

    Current controlled release formulations has many drawbacks such as excess of initial burst release, low drug efficiency, non-degradability of the system and low reproducibility. The present project aims to offer an alternative by developing a technique to prepare uniform, biodegradable particles ( ˜19 mum ) that can sustainably release a drug for a specific period of time. Chitosan is a natural polysaccharide that has many characteristics to be used for biomedical applications. In the last two decades, there have been a considerable number of studies affirming that chitosan could be used for pharmaceutical applications. However, chitosan suffers from inherent weaknesses such as low mechanical stability and dissolution of the system in acidic media. In the present study, chitosan microparticles were prepared by emulsification process. The model drug chosen was acetylsalicylic acid as it is a small and challenging molecule. The maximum loading capacity obtained for the microparticles was approximately 96%. The parameters for the preparation of uniform particles with a narrow size distribution were identified in a triangular phase diagram. Moreover, chitosan particles were successfully coated with thin layers of poly lactic-coglycolic acid (PLGA) and poly lactic acid (PLA). The performance of different layerswas tested for in vitro drug release and degradation studies. Additionally, the degradability of the system was evaluated by measuring the weight loss of the system when exposed to enzyme and without enzyme. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to characterize the controlled release system. Additionally, the in vitro drug release was monitored by ultraviolet-visible spectrophotometry (UV-Vis) and liquid chromatography mass spectrometry (LC-MS). The results obtained from this project showed that it is

  6. A novel ingestible electronic drug delivery and monitoring device.

    Science.gov (United States)

    van der Schaar, Peter J; Dijksman, J Frits; Broekhuizen-de Gast, Henny; Shimizu, Jeff; van Lelyveld, Niels; Zou, Hans; Iordanov, Ventzeslav; Wanke, Christoph; Siersema, Peter D

    2013-09-01

    We developed an ingestible electronic drug delivery and monitoring system. This system includes an electronic capsule comprising a drug reservoir, a pH and temperature sensor, a microprocessor and wireless transceiver, a stepper motor, and batteries. The location of the capsule in the gut derived from pH data can be monitored in real time. The stepper motor can be remotely actuated to expel the contents of the drug reservoir. First human study. Two consecutive observational studies. University medical center. Twenty healthy volunteers. Study I: Ingestion and passage of the capsule. Study II: Ingestion and passage of the capsule, loaded with (99m)technetium-pertechnetate ((99m)Tc); remotely actuated expulsion of (99m)Tc in the gut. Study I: Safety, tolerability, and functionality (wireless pH and temperature recording). Study II: Tracing of the capsule and expulsion and distribution of (99m)Tc from the drug reservoir by scintigraphy. Correlating location pH with scintigraphy. Study I: Ingestion and passage of the capsule was safe and well tolerated. Transmitted pH and temperature data were received by the recorder in 96.5% ± 3%. Study II: pH-determined passage of the esophagogastric, gastroduodenal, and ileocolonic junction correlated well with scintigraphy. Expulsion of (99m)Tc from the capsule was successful in 9 of 10 subjects. Subjects with relatively low body mass index. This electronic drug delivery and monitoring system may be a promising tool for targeted delivery of substances to well-defined areas of the GI tract. Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  7. Chitosan-Montmorillonite microspheres: A sustainable fertilizer delivery system.

    Science.gov (United States)

    dos Santos, Bruna Rodrigues; Bacalhau, Fabiana Britti; Pereira, Tamires dos Santos; Souza, Claudinei Fonseca; Faez, Roselena

    2015-08-20

    Controlled release fertilizers are efficient tools that increase the sustainability of agricultural practices. However, the biodegradability of the matrices and the determination of the release into soil still require some investigation. This paper describes the preparation of potassium-containing microspheres based on chitosan and montmorillonite clay and the in situ soil release. The chitosan-montmorillonite microspheres were prepared using a coagulation method and different proportions of montmorillonite. The structural, thermal and morphological properties as well the water swelling and fertilizer sorption capacity were evaluated. The best formulations were applied in soil, and the fertilizer release was monitored using time-domain reflectometry (TDR). Montmorillonite clay provides better sorption properties than the chitosan microspheres because of the rough and porous surface. Due to these properties, high levels of fertilizer were sorbed onto the material. ChMMT33-containing potassium shows two specific periods of fertilizer release: the first one lasted approximately three days and was assigned to the external fertilizer on the microspheres. The second was assigned to the internal fertilizer. TDR is an important and fast tool and was used to determine the fertilizer release and the ion movement in the soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. GM as a route for delivery of sustainable crop protection.

    Science.gov (United States)

    Bruce, Toby J A

    2012-01-01

    Modern agriculture, with its vast monocultures of lush fertilized crops, provides an ideal environment for adapted pests, weeds, and diseases. This vulnerability has implications for food security: when new pesticide-resistant pest biotypes evolve they can devastate crops. Even with existing crop protection measures, approximately one-third yield losses occur globally. Given the projected increase in demand for food (70% by 2050 according to the UN), sustainable ways of preventing these losses are needed. Development of resistant crop cultivars can make an important contribution. However, traditional crop breeding programmes are limited by the time taken to move resistance traits into elite crop genetic backgrounds and the limited gene pools in which to search for novel resistance. Furthermore, resistance based on single genes does not protect against the full spectrum of pests, weeds, and diseases, and is more likely to break down as pests evolve counter-resistance. Although not necessarily a panacea, GM (genetic modification) techniques greatly facilitate transfer of genes and thus provide a route to overcome these constraints. Effective resistance traits can be precisely and conveniently moved into mainstream crop cultivars. Resistance genes can be stacked to make it harder for pests to evolve counter-resistance and to provide multiple resistances to different attackers. GM-based crop protection could substantially reduce the need for farmers to apply pesticides to their crops and would make agricultural production more efficient in terms of resources used (land, energy, water). These benefits merit consideration by environmentalists willing to keep an open mind on the GM debate.

  9. Augmenting convection-enhanced delivery through simultaneous co-delivery of fluids and laser energy with a fiberoptic microneedle device

    Science.gov (United States)

    Hood, R. Lyle; Ecker, Tobias; Andriani, Rudy; Robertson, John; Rossmeisl, John; Rylander, Christopher G.

    2013-03-01

    This paper describes a new infusion catheter, based on our fiberoptic microneedle device (FMD), designed with the objective of photothermally augmenting the volumetric dispersal of infused therapeutics. We hypothesize that concurrent delivery of laser energy, causing mild localized photothermal heating (4-5 °C), will increase the spatial dispersal of infused chemotherapy over a long infusion period. Agarose brain phantoms, which mimic the brain's mechanical and fluid conduction properties, were constructed from 0.6 wt% Agarose in aqueous solution. FMDs were fabricated by adhering a multimode fiberoptic to a silica capillary tube, such that their flat-polished tips co-terminated. Continuous wave 1064 nm light was delivered simultaneously with FD&C Blue #2 (5%) dye into phantoms. Preliminary experiments, where co-delivery was tested against fluid delivery alone (through symmetrical infusions into in vivo rodent models), were also conducted. In the Agarose phantoms, volumetric dispersal was demonstrated to increase by more than 3-fold over a four-hour infusion time frame for co-delivery relative to infusion-only controls. Both forward and backward (reflux) infusions were also observed to increase slightly. Increased volumetric dispersal was demonstrated with co-delivery in an in vivo rodent model. Photothermal augmentation of infusion was demonstrated to influence the directionality and increase the volume of dye dispersal in Agarose brain phantoms. With further development, FMDs may enable a greater distribution of chemotherapeutic agents during CED therapy of brain tumors.

  10. Biopharmaceutical formulations for pre-filled delivery devices.

    Science.gov (United States)

    Jezek, Jan; Darton, Nicholas J; Derham, Barry K; Royle, Nikki; Simpson, Iain

    2013-06-01

    Pre-filled syringes are becoming an increasingly popular format for delivering biotherapeutics conveniently and cost effectively. The device design and stable liquid formulations required to enable this pre-filled syringe format are technically challenging. In choosing the materials and process conditions to fabricate the syringe unit, their compatibility with the biotherapeutic needs to be carefully assessed. The biothereaputic stability demanded for the production of syringe-compatible low-viscosity liquid solutions requires critical excipient choices to be made. The purpose of this review is to discuss key issues related to the stability aspects of biotherapeutics in pre-filled devices. This includes effects on both physical and chemical stability due to a number of stress conditions the product is subjected to, as well as interactions with the packaging system. Particular attention is paid to the control of stability by formulation. We anticipate that there will be a significant move towards polymer primary packaging for most drugs in the longer term. The timescales for this will depend on a number of factors and hence will be hard to predict. Formulation will play a critical role in developing successful products in the pre-filled syringe format, particularly with the trend towards concentrated biotherapeutics. Development of novel, smart formulation technologies will, therefore, be increasingly important.

  11. Comparison of devices for newborn ventilation in the delivery room.

    Science.gov (United States)

    Szyld, Edgardo; Aguilar, Adriana; Musante, Gabriel A; Vain, Nestor; Prudent, Luis; Fabres, Jorge; Carlo, Waldemar A

    2014-08-01

    To evaluate the effectiveness and safety of a T-piece resuscitator compared with a self-inflating bag for providing mask ventilation to newborns at birth. Newborns at ≥26 weeks gestational age receiving positive-pressure ventilation at birth were included in this multicenter cluster-randomized 2-period crossover trial. Positive-pressure ventilation was provided with either a self-inflating bag (self-inflating bag group) with or without a positive end-expiratory pressure valve or a T-piece with a positive end-expiratory pressure valve (T-piece group). Delivery room management followed American Academy of Pediatrics and International Liaison Committee on Resuscitation guidelines. The primary outcome was the proportion of newborns with heart rate (HR)≥100 bpm at 2 minutes after birth. A total of 1027 newborns were included. There was no statistically significant difference in the incidence of HR≥100 bpm at 2 minutes after birth between the T-piece and self-inflating bag groups: 94% (479 of 511) and 90% (466 of 516), respectively (OR, 0.65; 95% CI, 0.41-1.05; P=.08). A total of 86 newborns (17%) in the T-piece group and 134 newborns (26%) in the self-inflating bag group were intubated in the delivery room (OR, 0.58; 95% CI, 0.4-0.8; P=.002). The mean±SD maximum positive inspiratory pressure was 26±2 cm H2O in the T-piece group vs 28±5 cm H2O in the self-inflating bag group (Pmechanical ventilation did not differ significantly between groups. There was no difference between the T-piece resuscitator and a self-inflating bag in achieving an HR of ≥100 bpm at 2 minutes in newborns≥26 weeks gestational age resuscitated at birth. However, use of the T-piece decreased the intubation rate and the maximum pressures applied. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. ACTIVE DELIVERY CABLE TUNED TO DEVICE DEPLOYMENT STATE: ENHANCED VISIBILITY OF NITINOL OCCLUDERS DURING PRE-CLINICAL INTERVENTIONAL MRI

    Science.gov (United States)

    Bell, Jamie A.; Saikus, Christina E.; Ratnayaka, Kanishka; Barbash, Israel M.; Faranesh, Anthony Z.; Franson, Dominique N.; Sonmez, Merdim; Slack, Michael C.; Lederman, Robert J.; Kocaturk, Ozgur

    2012-01-01

    Purpose To develop an active delivery system that enhances visualization of nitinol cardiac occluder devices during deployment under real-time MRI. Materials and Methods We constructed an active delivery cable incorporating a loopless antenna and a custom titanium microscrew to secure the occluder devices. The delivery cable was tuned and matched to 50Ω at 64 MHz with the occluder device attached. We used real-time balanced SSFP in a wide-bore 1.5T scanner. Device-related images were reconstructed separately and combined with surface-coil images. The delivery cable was tested in vitro in a phantom and in vivo in swine using a variety of nitinol cardiac occluder devices. Results In vitro, the active delivery cable provided little signal when the occluder device was detached and maximal signal with the device attached. In vivo, signal from the active delivery cable enabled clear visualization of occluder device during positioning and deployment. Device release resulted in decreased signal from the active cable. Post-mortem examination confirmed proper device placement. Conclusions The active delivery cable enhanced the MRI depiction of nitinol cardiac occluder devices during positioning and deployment, both in conventional and novel applications. We expect enhanced visibility to contribute to effectiveness and safety of new and emerging MRI-guided treatments. PMID:22707441

  13. Nanostructured platforms for the sustained and local delivery of antibiotics in the treatment of osteomyelitis.

    Science.gov (United States)

    Uskokovic, Vuk

    2015-01-01

    This article provides a critical view of the current state of the development of nanoparticulate and other solid-state carriers for the local delivery of antibiotics in the treatment of osteomyelitis. Mentioned are the downsides of traditional means for treating bone infection, which involve systemic administration of antibiotics and surgical debridement, along with the rather imperfect local delivery options currently available in the clinic. Envisaged are more sophisticated carriers for the local and sustained delivery of antimicrobials, including bioresorbable polymeric, collagenous, liquid crystalline, and bioglass- and nanotube-based carriers, as well as those composed of calcium phosphate, the mineral component of bone and teeth. A special emphasis is placed on composite multifunctional antibiotic carriers of a nanoparticulate nature and on their ability to induce osteogenesis of hard tissues demineralized due to disease. An ideal carrier of this type would prevent the long-term, repetitive, and systemic administration of antibiotics and either minimize or completely eliminate the need for surgical debridement of necrotic tissue. Potential problems faced by even hypothetically "perfect" antibiotic delivery vehicles are mentioned too, including (i) intracellular bacterial colonies involved in recurrent, chronic osteomyelitis; (ii) the need for mechanical and release properties to be adjusted to the area of surgical placement; (iii) different environments in which in vitro and in vivo testings are carried out; (iv) unpredictable synergies between drug delivery system components; and (v) experimental sensitivity issues entailing the increasing subtlety of the design of nanoplatforms for the controlled delivery of therapeutics.

  14. Nanostructured Platforms for the Sustained and Local Delivery of Antibiotics in the Treatment of Osteomyelitis

    Science.gov (United States)

    Uskoković, Vuk

    2015-01-01

    This article provides a critical view of the current state of the development of nanoparticulate and other solid-state carriers for the local delivery of antibiotics in the treatment of osteomyelitis. Mentioned are the downsides of traditional means for treating bone infection, which involve systemic administration of antibiotics and surgical debridement, along with the rather imperfect local delivery options currently available in the clinic. Envisaged are more sophisticated carriers for the local and sustained delivery of antimicrobials, including bioresorbable polymeric, collagenous, liquid crystalline, and bioglass- and nanotube-based carriers, as well as those composed of calcium phosphate, the mineral component of bone and teeth. A special emphasis is placed on composite multifunctional antibiotic carriers of a nanoparticulate nature and on their ability to induce osteogenesis of hard tissues demineralized due to disease. An ideal carrier of this type would prevent the long-term, repetitive, and systemic administration of antibiotics and either minimize or completely eliminate the need for surgical debridement of necrotic tissue. Potential problems faced by even hypothetically “perfect” antibiotic delivery vehicles are mentioned too, including (i) intracellular bacterial colonies involved in recurrent, chronic osteomyelitis; (ii) the need for mechanical and release properties to be adjusted to the area of surgical placement; (iii) different environments in which in vitro and in vivo testings are carried out; (iv) unpredictable synergies between drug delivery system components; and (v) experimental sensitivity issues entailing the increasing subtlety of the design of nanoplatforms for the controlled delivery of therapeutics. PMID:25746204

  15. 27 CFR 478.98 - Sales or deliveries of destructive devices and certain firearms.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Sales or deliveries of destructive devices and certain firearms. 478.98 Section 478.98 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION COMMERCE...

  16. Delivery devices for exposure of biological cells to nanosecond pulsed electric fields.

    Science.gov (United States)

    Soueid, Malak; Dobbelaar, Martinus C F; Bentouati, Sabrina; Bardet, Sylvia M; O'Connor, Rodney P; Bessières, Delphine; Paillol, Jean; Leveque, Philippe; Arnaud-Cormos, Delia

    2018-01-01

    In this paper, delivery devices for nanosecond pulsed electric field exposure of biological samples in direct contact with electrodes or isolated are presented and characterized. They are based on a modified electroporation cuvette and two transverse electromagnetic cells (TEM cells). The devices were used to apply pulses with high intensity (4.5 kV) and short durations (3 and 13 ns). The delivery devices were electromagnetically characterized in the frequency and time domains. Field intensities of around 5, 0.5, and 12 MV m-1 were obtained by numerical simulations of the biological sample positioned in the three delivery devices. Two delivery systems had a homogenous electric field spatial distribution, and one was adapted to permit a highly localized exposure in the vicinity of a needle. Experimental biological investigations were carried out at different field intensities for five cancer cell lines. The results using flow cytometry showed that cells kept polarized mitochondrial membrane but lost plasma membrane integrity following a dose-response trend after exposure to different electric field intensities. Certain cell types (U87, MCF7) showed higher sensitivities to nsPEFs than other lines tested.

  17. Isotope-labelled urea to test colon drug delivery devices in vivo : principles, calculations and interpretations

    NARCIS (Netherlands)

    Maurer, Marina; Schellekens, Reinout C. A.; Wutzke, Klaus D.; Stellaard, Frans

    2013-01-01

    This paper describes various methodological aspects that were encountered during the development of a system to monitor the in vivo behaviour of a newly developed colon delivery device that enables oral drug treatment of inflammatory bowel diseases. [C-13]urea was chosen as the marker substance.

  18. Governing in a placeless environment: Sustainability and fish aggregating devices

    NARCIS (Netherlands)

    Bush, S.R.; Mol, A.P.J.

    2015-01-01

    Sustainability governance views ‘place’ as either a central concept and phenomenon to counter homogenising globalisation, or as an irrelevant concept for understanding ostensibly ‘placeless’ global environments such as oceans. Based on a review of global tuna fisheries in placeless oceans, we

  19. Self-assembled pentablock copolymers for selective and sustained gene delivery

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingqi [Iowa State Univ., Ames, IA (United States)

    2011-05-15

    The poly(diethylaminoethyl methacrylate) (PDEAEM) - Pluronic F127 - PDEAEM pentablock copolymer (PB) gene delivery vector system has been found to possess an inherent selectivity in transfecting cancer cells over non-cancer cells in vitro, without attaching any targeting ligands. In order to understand the mechanism of this selective transfection, three possible intracellular barriers to transfection were investigated in both cancer and non-cancer cells. We concluded that escape from the endocytic pathway served as the primary intracellular barrier for PB-mediated transfection. Most likely, PB vectors were entrapped and rendered non-functional in acidic lysosomes of non-cancer cells, but survived in less acidic lysosomes of cancer cells. The work highlights the importance of identifying intracellular barriers for different gene delivery systems and provides a new paradigm for designing targeting vectors based on intracellular differences between cell types, rather than through the use of targeting ligands. The PB vector was further developed to simultaneously deliver anticancer drugs and genes, which showed a synergistic effect demonstrated by significantly enhanced gene expression in vitro. Due to the thermosensitive gelation behavior, the PB vector packaging both drug and gene was also investigated for its in vitro sustained release properties by using polyethylene glycol diacrylate as a barrier gel to mimic the tumor matrix in vivo. Overall, this work resulted in the development of a gene delivery vector for sustained and selective gene delivery to tumor cells for cancer therapy.

  20. Covalent modification of pericardial patches for sustained rapamycin delivery inhibits venous neointimal hyperplasia

    Science.gov (United States)

    Bai, Hualong; Lee, Jung Seok; Chen, Elizabeth; Wang, Mo; Xing, Ying; Fahmy, Tarek M.; Dardik, Alan

    2017-01-01

    Prosthetic grafts and patches are commonly used in cardiovascular surgery, however neointimal hyperplasia remains a significant concern, especially under low flow conditions. We hypothesized that delivery of rapamycin from nanoparticles (NP) covalently attached to patches allows sustained site-specific delivery of therapeutic agents targeted to inhibit localized neointimal hyperplasia. NP were covalently linked to pericardial patches using EDC/NHS chemistry and could deliver at least 360 ng rapamycin per patch without detectable rapamycin in serum; nanoparticles were detectable in the liver, kidney and spleen but no other sites within 24 hours. In a rat venous patch angioplasty model, control patches developed robust neointimal hyperplasia on the patch luminal surface characterized by Eph-B4-positive endothelium and underlying SMC and infiltrating cells such as macrophages and leukocytes. Patches delivering rapamycin developed less neointimal hyperplasia, less smooth muscle cell proliferation, and had fewer infiltrating cells but retained endothelialization. NP covalently linked to pericardial patches are a novel composite delivery system that allows sustained site-specific delivery of therapeutics; NP delivering rapamycin inhibit patch neointimal hyperplasia. NP linked to patches may represent a next generation of tissue engineered cardiovascular implants.

  1. Dissolving and biodegradable microneedle technologies for transdermal sustained delivery of drug and vaccine

    Directory of Open Access Journals (Sweden)

    Hong X

    2013-09-01

    Full Text Available Xiaoyun Hong,1,2,* Liangming Wei,3,* Fei Wu,2,* Zaozhan Wu,2 Lizhu Chen,2 Zhenguo Liu,1 Weien Yuan2 1Department of Neurology, Xinhua Hospital, Shanghai, People's Republic of China; 2School of Pharmacy, Shanghai JiaoTong University, Shanghai, People's Republic of China; 3Research Institute of Micro/Nano Science and Technology, Shanghai JiaoTong University, Shanghai, People's Republic of China *These authors contributed equally to this work Abstract: Microneedles were first conceptualized for drug delivery many decades ago, overcoming the shortages and preserving the advantages of hypodermic needle and conventional transdermal drug-delivery systems to some extent. Dissolving and biodegradable microneedle technologies have been used for transdermal sustained deliveries of different drugs and vaccines. This review describes microneedle geometry and the representative dissolving and biodegradable microneedle delivery methods via the skin, followed by the fabricating methods. Finally, this review puts forward some perspectives that require further investigation. Keywords: microneedle, dissolving, biodegradable, sustained release

  2. Lyophilized Silk Fibroin Hydrogels for the Sustained Local Delivery of Therapeutic Monoclonal Antibodies

    Science.gov (United States)

    Guziewicz, Nicholas; Best, Annie; Perez-Ramirez, Bernardo; Kaplan, David L.

    2011-01-01

    The development of sustained delivery systems compatible with protein therapeutics continues to be a significant unmet need. A lyophilized silk fibroin hydrogel matrix (lyogel) for the sustained release of pharmaceutically relevant monoclonal antibodies is described. Sonication of silk fibroin prior to antibody incorporation avoids exposing the antibody to the sol-gel transition inducing shear stress. Fourier Transform Infrared (FTIR) analysis showed no change in silk structural composition between hydrogel and lyogel or with increasing silk fibroin concentration. Antibody release from hydrogels occurred rapidly over 10 days regardless of silk concentration. Upon lyophilization, sustained antibody release was observed over 38 days from lyogels containing 6.2% (w/w) silk fibroin and above. In 3.2% (w/w) silk lyogels, antibody release was comparable to hydrogels. Swelling properties of lyogels followed a similar threshold behavior. Lyogels at 3.2% (w/w) silk recovered approximately 90% of their fluid mass upon rehydration, while approximately 50% fluid recovery was observed at 6.2% (w/w) silk and above. Antibody release was primarily governed by hydrophobic/hydrophilic silk-antibody interactions and secondarily altered by the hydration resistance of the lyogel. Hydration resistance was controlled by altering β-sheet (crystalline) density of the matrix. The antibody released from lyogels maintained biological activity. Silk lyogels offer an advantage as a delivery matrix over other hydrogel materials for the slow release of the loaded protein, making lyogels suitable for long-term sustained release applications. PMID:21216004

  3. Porous tube plant nutrient delivery system development: A device for nutrient delivery in microgravity

    Science.gov (United States)

    Dreschel, T. W.; Brown, C. S.; Piastuch, W. C.; Hinkle, C. R.; Knott, W. M.

    1994-01-01

    The Porous Tube Plant Nutrient Delivery Systems or PTPNDS (U.S. Patent #4,926,585) has been under development for the past six years with the goal of providing a means for culturing plants in microgravity, specifically providing water and nutrients to the roots. Direct applications of the PTPNDS include plant space biology investigations on the Space Shuttle and plant research for life support in the Space Station Freedom. In the past, we investigated various configurations, the suitability of different porous materials, and the effects of pressure and pore size on plant growth. Current work is focused on characterizing the physical operation of the system, examining the effects of solution aeration, and developing prototype configurations for the Plant Growth Unit (PGU), the flight system for the Shuttle mid-deck. Future developments will involve testing on KC-135 parabolic flights, the design of flight hardware and testing aboard the Space Shuttle.

  4. Transdermal delivery of ketorolac tromethamine: permeation enhancement, device design, and pharmacokinetics in healthy humans.

    Science.gov (United States)

    Roy, S D; Manoukian, E

    1995-10-01

    Transdermal delivery of ketorolac tromethamine, a potent non-narcotic analgesic, through human skin in vitro and in vivo was investigated. In order to enhance and sustain the flux of ketorolac through human skin, various compositions of isopropyl alcohol (IPA), water, and isopropyl myristate (IPM) were evaluated. The solubility of ketorolac acid in an IPA/water binary vehicle mixture increased as the volume fraction of IPA increased from 0 to 90%. The solubility of ketorolac acid in an IPA/water/IPM (saturated) ternary vehicle mixture was practically the same as in the IPA/water binary vehicle mixture. The permeation of ketorolac acid through cadaver skin was evaluated using modified Franz diffusion cells. The skin flux increased as the IPA volume fraction was increased from 0 to 50% and then leveled off beyond 80% IPA loading. When IPM was added to the IPA/water binary vehicle mixture, a significant increase in the skin flux of ketorolac was observed. The skin flux decreased exponentially as the donor solution pH was raised from 3.5 to 7.0. The permeability of ketorolac through various membranes such as a microporous membrane and pressure-sensitive adhesive was evaluated. While a microporous membrane offered practically no diffusion resistance, the in vitro flux of ketorolac through cadaver skin decreased substantially upon lamination of pressure-sensitive adhesive onto a microporous membrane. Three liquid-reservoir type transdermal devices were fabricated using 6.5% ketorolac tromethamine gel, a microporous membrane, an adhesive membrane, and polyester backing film: TD-A (microporous membrane/acrylic adhesive), TD-B (microporous membrane/silicone adhesive), and TD-C (microporous membrane). The pharmacokinetics of ketorolac in 10 healthy humans following application of a transdermal device for 24 h was evaluated. The maximum plasma concentrations (Cmax) were 0.20, 0.18, and 0.82 microgram/mL for TD-A, TD-B, and TD-C, respectively. The total AUC values for the

  5. [Bench-test evaluation of spacer devices for fluticasone delivery to infants].

    Science.gov (United States)

    Pourchez, J; Leclerc, L; Sarry, G; Vergnon, J-M; Dubus, J C

    2017-01-01

    Use of a spacer device to optimize the delivery of fluticasone to infants with asthma is an important issue and clinicians require guidance around the choice of device. This in vitro study characterizes the particle size and the fluticasone delivery via 9 spacers. We used an in vitro infant nasal cast with two different inspiratory flow rates (50 and 100mL/s). Fluticasone particle size in the aerosol was evaluated by laser diffractometry and tracheal deposition by spectrophotometric assay. Significant differences in particle size were observed between the 9 spacers (similar D50 but D90 from 5.65±0.65 to 8.80±1.35μm). A 75 % or higher respirable fraction was obtained for only 5 spacers. The 50mL/s flow rate lead to the best drug delivery. At this flow, OptiChamber(®) (62±3 %) and Vortex(®) (91±8.5 %) had a tracheal deposition over 50 % of the initial dose of fluticasone, although the 7 other spacers exhibited a fluticasone deposition less than 25 %. This study shows a wide variation of drug delivery between the 9 spacers studied. We demonstrate that a low inspiratory flow and a spacer showing antistatic properties facilitate drug delivery. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  6. Optimising Inhaled Pharmacotherapy for Elderly Patients with Chronic Obstructive Pulmonary Disease: The Importance of Delivery Devices.

    Science.gov (United States)

    Lavorini, Federico; Mannini, Claudia; Chellini, Elisa; Fontana, Giovanni A

    2016-07-01

    Chronic obstructive pulmonary disease (COPD) is common in older people. Inhaled medications are the mainstay of pharmacological treatment of COPD, and are typically administered by handheld inhalers, such as pressurised metered-dose inhalers and dry powder inhalers, or by nebulisers. For each of the three major categories of aerosol delivery devices, several new inhalers have recently been launched, each with their own particularities, advantages and disadvantages. Consequently, broader availability of new drug-device combinations will increase prescription opportunities. Despite this, however, there is limited guidance available in published guidelines on the choice of inhalers, and still less consideration is given to elderly patients with COPD. The aim of this article is to provide a guide for healthcare professionals on device selection and factors to be considered for effective inhaled drug delivery in elderly COPD patients, including device factors (device type and complexity of use), patient factors (inspiratory capabilities, manual dexterity and hand strength, cognitive ability, co-morbidities) and considerations for healthcare professionals (proper education of patients in device use).

  7. A controlled and sustained local gentamicin delivery system for inner ear applications.

    Science.gov (United States)

    Xu, Lei; Heldrich, Jonna; Wang, Haibo; Yamashita, Taku; Miyamoto, Shunsuke; Li, Andrew; Uboh, Cornelius E; You, Youwen; Bigelow, Douglas; Ruckenstein, Michael; O'Malley, Bert; Li, Daqing

    2010-09-01

    Intratympanic gentamicin injection (ITGI) has gained acceptance worldwide for the treatment of Ménière's disease. Reports assessing the efficacy of ITGI suffer from high variability between patients. This variability may be due to ITGI, which does not permit a sustained diffusion of gentamicin across the round window membrane. The present study investigates the effectiveness of a sustained local hydrogel system on the delivery of gentamicin into the inner ear for the treatment of Ménière's disease. A matrix of hydrogel loaded with/without gentamicin was explored in vivo. Gentamicin was applied to the ear of mice either through ITGI or in the hydrogel system. Pharmacokinetics, hearing, and balance function were examined to study how the hydrogel system affected the gentamicin delivery and inner ear functions. The 2 gentamicin delivery methods yielded different kinetics curves. The hydrogel system achieved sustained release during a 7-day period, with a flat plateau phase from Day 1 to Day 3 and slow descent in the subsequent days. The ITGI curve dramatically declined after the peak concentration at Day 1 and was almost eliminated by Day 3. The hydrogel system yielded noticeable balance dysfunction with no significant hearing changes. In contrast, ITGI exhibited no significant influences on the inner ear functions after applying the same dose of 40 kg of gentamicin. The hydrogel system established in this research allows for more sustained and consistent and efficient drug release than traditional ITGI for the transport of gentamicin into the inner ear, offering a new and exciting treatment of Ménière's disease.

  8. Hyaluronan microgel as a potential carrier for protein sustained delivery by tailoring the crosslink network

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Chunhong [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Zhao, Jianhao, E-mail: jhzhao@jnu.edu.cn [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Tu, Mei; Zeng, Rong; Rong, Jianhua [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China)

    2014-03-01

    Hyaluronan (HA) microgels with different crosslink network, i.e. HGPs-1, HGPs-1.5, HGPs-3, HGPs-6 and HGPs-15, were synthesized using divinyl sulfone (DVS) as the crosslinker in an inverse microemulsion system for controlling the sustained delivery of bovine serum albumin (BSA). With increasing the crosslinker content, the average particle size slightly increased from 1.9 ± 0.3 μm to 3.6 ± 0.5 μm by dynamic laser scattering analysis. However, the crosslinker content had no significant effect on the morphology of HA microgels by scanning and transmission electron microscopes. Fourier transform infrared spectroscopy and elemental analysis proved more sulfur participated in the crosslink reaction when raising the crosslinker amount. The water swelling test confirmed the increasing crosslink density with the crosslinker content by calculating the average molecular weight between two crosslink points to be 8.25 ± 2.51 × 10{sup 5}, 1.26 ± 0.43 × 10{sup 5}, 0.96 ± 0.09 × 10{sup 5}, 0.64 ± 0.03 × 10{sup 5}, and 0.11 ± 0.01 × 10{sup 5} respectively. The degradation of HA microgels by hyaluronidase slowed down by enhancing the crosslink density, only about 5% of HGPs-15 was degraded as opposed to over 90% for HGPs-1. BSA loading had no obvious influence on the surface morphology of HA microgels but seemed to induce their aggregation. The increase of crosslink density decreased the BSA loading capacity but facilitated its long-term sustained delivery. When the molar ratio of DVS to repeating unit of HA reached 3 or higher, similar delivery profiles were obtained. Among all these HA microgels, HGPs-3 was the optimal carrier for BSA sustained delivery in this system because it possessed both high BSA loading capacity and long-term delivery profile simultaneously. - Highlights: • HA microgels with different crosslink densities were prepared. • The crosslinker content had little effect on the morphology and size of HA microgels. • The crosslink density

  9. Group purchasing organizations: optimizing cardiac device selection, therapy delivery, and fiscal responsibility.

    Science.gov (United States)

    Sweesy, Mark W; Wilkoff, Bruce L; Smith, Kerry W; Holland, James L

    2006-12-01

    Group purchasing organizations (GPOs) have played a major role in supporting health care delivery in recent years as the healthcare industry has faced stronger economic pressures. Consequently, a position statement was drafted to act as a guideline for a GPO in creating a fiscally responsible, yet unrestricted environment for physicians to select the most appropriate cardiac device for their patients. This cardiac device selection guideline is to be implemented in hundreds of member hospitals but may be of use in non-member hospitals as well. The guideline will only be effective when the physicians or cardiac device caregivers have the knowledge and skills to optimally program and match device therapies and algorithms to individual patient needs.

  10. Controlled delivery of antiangiogenic drug to human eye tissue using a MEMS device

    KAUST Repository

    Pirmoradi, Fatemeh Nazly

    2013-01-01

    We demonstrate an implantable MEMS drug delivery device to conduct controlled and on-demand, ex vivo drug transport to human eye tissue. Remotely operated drug delivery to human post-mortem eyes was performed via a MEMS device. The developed curved packaging cover conforms to the eyeball thereby preventing the eye tissue from contacting the actuating membrane. By pulsed operation of the device, using an externally applied magnetic field, the drug released from the device accumulates in a cavity adjacent to the tissue. As such, docetaxel (DTX), an antiangiogenic drug, diffuses through the eye tissue, from sclera and choroid to retina. DTX uptake by sclera and choroid were measured to be 1.93±0.66 and 7.24±0.37 μg/g tissue, respectively, after two hours in pulsed operation mode (10s on/off cycles) at 23°C. During this period, a total amount of 192 ng DTX diffused into the exposed tissue. This MEMS device shows great potential for the treatment of ocular posterior segment diseases such as diabetic retinopathy by introducing a novel way of drug administration to the eye. © 2013 IEEE.

  11. Gelatin device for the delivery of growth factors involved in endochondral ossification.

    Directory of Open Access Journals (Sweden)

    Lucas A J Ahrens

    Full Text Available Controlled release drug delivery systems are well established as oral and implantable dosage forms. However, the controlled release paradigm can also be used to present complex soluble signals responsible for cellular organization during development. Endochondral ossification (EO, the developmental process of bone formation from a cartilage matrix is controlled by several soluble signals with distinct functions that vary in structure, molecular weight and stability. This makes delivering them from a single vehicle rather challenging. Herein, a gelatin-based delivery system suitable for the delivery of small molecules as well as recombinant human (rh proteins (rhWNT3A, rhFGF2, rhVEGF, rhBMP4 is reported. The release behavior and biological activity of the released molecules was validated using analytical and biological assays, including cell reporter systems. The simplicity of fabrication of the gelatin device should foster its adaptation by the diverse scientific community interested in interrogating developmental processes, in vivo.

  12. Effects of endoscopic sinus surgery and delivery device on cadaver sinus irrigation.

    Science.gov (United States)

    Harvey, Richard J; Goddard, John C; Wise, Sarah K; Schlosser, Rodney J

    2008-07-01

    Assess paranasal sinus distribution of topical solutions following endoscopic sinus surgery (ESS) using various delivery devices. Experimental prospective study. Ten cadaver sinus systems were irrigated with Gastroview before surgery, after ESS, and after medial maxillectomy. Delivery was via pressurized spray (NasaMist), neti pot (NasaFlo), and squeeze bottle (Sinus Rinse). Scans were performed before and after each delivery with a portable CT machine (Xoran xCAT), and blinded assessments were made for distribution to individual sinuses. Total sinus distribution was greater post-ESS (P squeeze bottle > pressurized spray (P spray solutions in un-operated sinuses provide little more than nasal cavity distribution. Use of squeeze bottle/neti pot post-ESS offers a greatly enhanced ability to deliver solutions to the paranasal sinuses.

  13. Sustainable strategies for nano-in-micro particle engineering for pulmonary delivery

    Science.gov (United States)

    Silva, A. Sofia; Tavares, Márcia T.; Aguiar-Ricardo, Ana

    2014-11-01

    With the increasing popularity and refinement of inhalation therapy, there has been a huge demand for the design and development of fine-tuned inhalable drug particles capable of assuring an efficient delivery to the lungs with optimal therapeutic outcomes. To cope with this demand, novel particle technologies have arisen over the last decade agreeing with the progress of pulmonary therapeutics that were commonly given by injection. Nanotechnology holds a considerable potential in the development of new release mechanisms of active ingredients to the deep lungs. For an accurate deep lung deposition and effective delivery of nanoparticles, respirable nano-in-micro formulations have been extensively investigated. Microparticles with nanoscale features can now be developed, and their functionalities have contributed to stabilize and improve the efficacy of the particulated dosage form. This paper reviews the different types of the aerosolizable nano-in-micro particles, as well as their sustainable production and characterization processes as dry powders. This review also intends to provide a critical insight of the current goals and technologies of particle engineering for the development of pulmonary drug delivery systems with a special emphasis on nano-micro dry powder formulations prepared by spray-drying and supercritical fluid-assisted techniques. The merits and limitations of these technologies are debated with reference to their appliance to specific drug and/or excipient materials. Finally, a list of most recent/ongoing clinical trials regarding pulmonary delivery of this type of formulation is described.

  14. Characterization of cubosomes as a targeted and sustained transdermal delivery system for capsaicin

    Directory of Open Access Journals (Sweden)

    Peng X

    2015-08-01

    Full Text Available Xinsheng Peng,1* Yanfang Zhou,1* Ke Han,2,3 Lingzhen Qin,3 Linghui Dian,1 Ge Li,4 Xin Pan,3 Chuanbin Wu3 1Guangdong Medical University, Dongguan, 2The Second Affiliated Hospital of Guangzhou Medical University, 3School of Pharmaceutical Sciences, Sun Yat-Sen University, 4Guangzhou Neworld Pharmaceuticals Co. Ltd., Guangzhou, Guangdong, People’s Republic of China*These authors contributed equally to this work Abstract: Phytantriol- and glycerol monooleate-based cubosomes were produced and characterized as a targeted and sustained transdermal delivery system for capsaicin. The cubosomes were prepared by emulsification and homogenization of phytantriol (F1, glycerol monooleate (F2, and poloxamer dispersions, characterized for morphology and particle size distribution by transmission electron microscope and photon correlation spectroscopy. Their Im3m crystallographic space group was confirmed by small-angle X-ray scattering. An in vitro release study showed that the cubosomes provided a sustained release system for capsaicin. An in vitro diffusion study conducted using Franz diffusion cells indicated that the skin retention of capsaicin from cubosomes in the stratum corneum was much higher (2.75±0.22 µg versus 4.32±0.13 µg, respectively than that of capsaicin cream (0.72±0.13 µg. The stress testing showed that the cubosome formulations were stable under strong light and high temperature for up to 10 days. After multiapplications on mouse skin, the irritation of capsaicin cubosomes and cream was light with the least amount of side effects. Overall, the present study demonstrated that cubosomes may be a suitable skin-targeted and sustained delivery system for the transdermal administration of capsaicin. Keywords: cubosomes, skin-targeted delivery, capsaicin

  15. Hyaluronan microgel as a potential carrier for protein sustained delivery by tailoring the crosslink network.

    Science.gov (United States)

    Luo, Chunhong; Zhao, Jianhao; Tu, Mei; Zeng, Rong; Rong, Jianhua

    2014-03-01

    Hyaluronan (HA) microgels with different crosslink network, i.e. HGPs-1, HGPs-1.5, HGPs-3, HGPs-6 and HGPs-15, were synthesized using divinyl sulfone (DVS) as the crosslinker in an inverse microemulsion system for controlling the sustained delivery of bovine serum albumin (BSA). With increasing the crosslinker content, the average particle size slightly increased from 1.9 ± 0.3 μm to 3.6 ± 0.5 μm by dynamic laser scattering analysis. However, the crosslinker content had no significant effect on the morphology of HA microgels by scanning and transmission electron microscopes. Fourier transform infrared spectroscopy and elemental analysis proved more sulfur participated in the crosslink reaction when raising the crosslinker amount. The water swelling test confirmed the increasing crosslink density with the crosslinker content by calculating the average molecular weight between two crosslink points to be 8.25 ± 2.51 × 10(5), 1.26 ± 0.43 × 10(5), 0.96 ± 0.09 × 10(5), 0.64 ± 0.03 × 10(5), and 0.11 ± 0.01 × 10(5) respectively. The degradation of HA microgels by hyaluronidase slowed down by enhancing the crosslink density, only about 5% of HGPs-15 was degraded as opposed to over 90% for HGPs-1. BSA loading had no obvious influence on the surface morphology of HA microgels but seemed to induce their aggregation. The increase of crosslink density decreased the BSA loading capacity but facilitated its long-term sustained delivery. When the molar ratio of DVS to repeating unit of HA reached 3 or higher, similar delivery profiles were obtained. Among all these HA microgels, HGPs-3 was the optimal carrier for BSA sustained delivery in this system because it possessed both high BSA loading capacity and long-term delivery profile simultaneously. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Starch/Carbopol spray-dried mixtures as excipients for oral sustained drug delivery.

    Science.gov (United States)

    Pringels, E; Ameye, D; Vervaet, C; Foreman, P; Remon, J P

    2005-04-18

    The present study evaluated if mixtures prepared by spray-drying an aqueous dispersion of Amioca starch and Carbopol 974P could be used as matrix for oral sustained drug delivery. The influence of the Amioca/Carbopol 974P ratio (0/100, 25/75, 50/50, 60/40, 85/15, 90/10, 95/5 and 100/0) and the pH and ionic strength (mu) of the dissolution medium on the drug release was investigated. The matrices composed of the spray-dried mixtures with 10% or 15% Carbopol 974P sustained the drug release over the longest time period. At this Carbopol concentration, shear viscosity measurements indicated the formation of an optimal network between the polymer chains of Amioca starch and Carbopol 974P, forming a rigid gel layer offering resistance to erosion during the dissolution experiments.

  17. Self-tracking devices and sustainable labour participation of older workers

    NARCIS (Netherlands)

    Dr. Hugo Velthuijsen; Dr. Louis Polstra; Dr. Martijn de Groot; Dr. Hilbrand Oldenhuis

    2013-01-01

    Sustainable labour participation: • Vitality • Employability • Workability Self-tracking devices can be used to alter behaviors and increase self efficiency/empowerment Result: –more self efficacy concerning employability –behavioral change in important (health) domains –more empowerment of

  18. Self-tracking devices and sustainable labour participation of older workers

    NARCIS (Netherlands)

    Dr. Hilbrand Oldenhuis

    2014-01-01

    Presentation: Self-tracking devices as a means to increase self insight and self management when it comes to health behavior. Result: higher level of sustainable employability, because workers are more self confident and are better equipped when it comes to health behavior

  19. Application of a three-microneedle device for the delivery of local anesthetics

    Directory of Open Access Journals (Sweden)

    Ishikawa K

    2015-04-01

    Full Text Available Kayoko Ishikawa,1 Hidekazu Fukamizu,1 Tetsuya Takiguchi,1 Yusuke Ohta,1 Yoshiki Tokura2 1Department of Plastic and Reconstructive Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan; 2Department of Dermatology, Hamamatsu University School of Medicine, Hamamatsu, Japan Purpose: We investigated the effectiveness of a newly developed device for the delivery of local anesthetics in the treatment of axillary osmidrosis and hyperhidrosis. We developed a device with three fine, stainless steel needles fabricated with a bevel angle facing outside (“three-microneedle device” [TMD] to release a drug broadly and homogeneously into tissue in the horizontal plane. Use of this device could reduce the risk of complications when transcutaneous injections are undertaken.Patients and methods: Sixteen Japanese patients were enrolled. The mean volume of lidocaine hydrochloride per unit area needed to elicit anesthesia when using a TMD was compared with that the volume required when using a conventional 27-gauge needle. The visual analog scale (VAS score of needlestick pain and injection-associated pain was also compared.Results: The mean volume of lidocaine hydrochloride per unit area to elicit anesthesia using the TMD was significantly lower than that the volume required when using the conventional 27-gauge needle. The VAS score of needlestick pain for the TMD was significantly lower than that the VAS score for the 27-gauge needle.Conclusion: These data suggest that the TMD could be useful for the delivery of local anesthetics in terms of clinical efficacy and avoidance of adverse effects. Keywords: three-microneedle device, transcutaneous drug delivery, local anesthesia, lidocaine, pain

  20. Development of PEGylated PLGA nanoparticle for controlled and sustained drug delivery in cystic fibrosis

    Directory of Open Access Journals (Sweden)

    Mazur Steven

    2010-09-01

    Full Text Available Abstract Background The mutation in the cystic fibrosis transmembrane conductance regulator (CFTR gene results in CF. The most common mutation, ΔF508-CFTR, is a temperature-sensitive, trafficking mutant with reduced chloride transport and exaggerated immune response. The ΔF508-CFTR is misfolded, ubiquitinated, and prematurely degraded by proteasome mediated- degradation. We recently demonstrated that selective inhibition of proteasomal pathway by the FDA approved drug PS-341 (pyrazylcarbonyl-Phe-Leuboronate, a.k.a. Velcade or bortezomib ameliorates the inflammatory pathophysiology of CF cells. This proteasomal drug is an extremely potent, stable, reversible and selective inhibitor of chymotryptic threonine protease-activity. The apprehension in considering the proteasome as a therapeutic target is that proteasome inhibitors may affect proteostasis and consecutive processes. The affect on multiple processes can be mitigated by nanoparticle mediated PS-341 lung-delivery resulting in favorable outcome observed in this study. Results To overcome this challenge, we developed a nano-based approach that uses drug loaded biodegradable nanoparticle (PLGA-PEGPS-341 to provide controlled and sustained drug delivery. The in vitro release kinetics of drug from nanoparticle was quantified by proteasomal activity assay from days 1-7 that showed slow drug release from day 2-7 with maximum inhibition at day 7. For in vivo release kinetics and biodistribution, these drug-loaded nanoparticles were fluorescently labeled, and administered to C57BL6 mice by intranasal route. Whole-body optical imaging of the treated live animals demonstrates efficient delivery of particles to murine lungs, 24 hrs post treatment, followed by biodegradation and release over time, day 1-11. The efficacy of drug release in CF mice (Cftr-/- lungs was determined by quantifying the changes in proteasomal activity (~2 fold decrease and ability to rescue the Pseudomonas aeruginosa LPS (Pa

  1. Aloe vera in active and passive regions of electronic devices towards a sustainable development

    Science.gov (United States)

    Lim, Zhe Xi; Sreenivasan, Sasidharan; Wong, Yew Hoong; Cheong, Kuan Yew

    2017-07-01

    The increasing awareness towards sustainable development of electronics has driven the search for natural bio-organic materials in place of conventional electronic materials. The concept of using natural bio-organic materials in electronics provides not only an effective solution to address global electronic waste crisis, but also a compelling template for sustainable electronics manufacturing. This paper attempts to provide an overview of using Aloe vera gel as a natural bio-organic material for various electronic applications. Important concepts such as responses of living Aloe vera plant towards electrical stimuli and demonstrations of Aloe vera films as passive and active regions of electronic devices are highlighted in chronological order. The biodegradability and biocompatibility of Aloe vera can bring the world a step closer towards the ultimate goal of sustainable development of electronic devices from "all-natural" materials.

  2. Levels of sirolimus in saliva and blood following oral topical sustained-release varnish delivery system application.

    Science.gov (United States)

    Nudelman, Zakhar; Findler, Mordechai; Barasch, Dinorah; Nemirovski, Alina; Pikovsky, Anna; Kirmayer, David; Basheer, Maamoun; Gutkind, J Silvio; Friedman, Michael; Czerninski, Rakefet

    2015-05-01

    Sirolimus (rapamycin) is a mammalian target of rapamycin pathway blocker. The efficacy of sirolimus is currently studied for its antiproliferative properties in various malignancies and particularly in squamous cell carcinoma and other oral disorders. Topical application at the oral cavity can augment sirolimus availability at the site of action by increasing sirolimus levels in saliva and hence efficacy, along with improved safety (low levels in the blood to avoid side effects) and compliance. Our purpose was to evaluate the release profile and safety of a topical sirolimus sustained-release varnish drug delivery system. Sirolimus sustained-release varnish drug delivery system containing a total of 0.5 mg of the drug was applied to nine healthy male volunteers. Saliva and blood levels were determined utilizing mass spectrometry and chemiluminescent microparticle immunoassay, respectively. The prolonged release profile and safety were evaluated for the oral topical delivery system. After the application of the drug delivery system, a sustained-release profile was observed in the oral cavity. We have measured moderate sirolimus levels for up to 12 h. The safety was confirmed, and systemic sirolimus blood levels were negligible. After an application of sirolimus sustained-release varnish drug delivery system, prolonged drug levels can be achieved in the saliva. The oral topical sirolimus concentrations were potentially therapeutic along with minimal systemic exposure. These results broaden the potential clinical use of sustained-release oral topical rapalogs.

  3. Uniquely different PVA-xanthan gum irradiated membranes as transdermal diltiazem delivery device.

    Science.gov (United States)

    Bhunia, Tridib; Giri, Arindam; Nasim, Tanbir; Chattopadhyay, Dipankar; Bandyopadhyay, Abhijit

    2013-06-05

    This paper reports interesting differences between physical and mechanical properties of various membranes prepared from high and low molecular weight poly (vinyl alcohol) (PVA) and xanthan gum (XG) blends irradiated under low dose electron beam. The membranes were designed for sustained delivery of diltiazem hydrochloride through skin. Electron beam irradiation produced crosslinks and turned PVA into crystalline phase from its amorphous organization in the unirradiated state. PVA crystals were fibrillar at low XG content (1 wt.%) when the molecular weight was high while similar orientation at higher XG content (5 wt.%) when the molecular weight was low. Low molecular weight PVA-XG membranes showed equivalent physical properties under dry condition but wet-mechanical properties were superior for high molecular weight PVA-XG hybrids. Both of them showed slow and sustained diltiazem release but the later induced slightly slower release despite low drug encapsulation efficiency due to its better wet mechanical strength. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Sustained delivery of VEGF from designer self-assembling peptides improves cardiac function after myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hai-dong [Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203 (China); Cui, Guo-hong; Yang, Jia-jun [Department of Neurology, Shanghai No. 6 People' s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200233 (China); Wang, Cun [Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Zhu, Jing; Zhang, Li-sheng; Jiang, Jun [Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203 (China); Shao, Shui-jin, E-mail: shaoshuijin@163.com [Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203 (China)

    2012-07-20

    Highlights: Black-Right-Pointing-Pointer The designer peptide LRKKLGKA could self-assemble into nanofibers. Black-Right-Pointing-Pointer Injection of LRKKLGKA peptides could promote the sustained delivery of VEGF. Black-Right-Pointing-Pointer Injection of VEGF with LRKKLGKA peptides lead to sufficient angiogenesis. Black-Right-Pointing-Pointer Injection of VEGF with LRKKLGKA peptides improves heart function. -- Abstract: Poor vascularization and insufficient oxygen supply are detrimental to the survival of residual cardiomyocytes or transplanted stem cells after myocardial infarction. To prolong and slow the release of angiogenic factors, which stimulate both angiogenesis and vasculogenesis, we constructed a novel self-assembling peptide by attaching the heparin-binding domain sequence LRKKLGKA to the self-assembling peptide RADA16. This designer self-assembling peptide self-assembled into nanofiber scaffolds under physiological conditions, as observed by atomic force microscopy. The injection of designer self-assembling peptides can efficiently provide the sustained delivery of VEGF for at least 1 month. At 4 weeks after transplantation, cardiac function was improved, and scar size and collagen deposition were markedly reduced in the group receiving VEGF with the LRKKLGKA scaffolds compared with groups receiving VEGF alone, LRKKLGKA scaffolds alone or VEGF with RADA16 scaffolds. The microvessel density in the VEGF with LRKKLGKA group was higher than that in the VEGF with RADA16 group. TUNEL and cleaved caspase-3 expression assays showed that the transplantation of VEGF with LRKKLGKA enhanced cell survival in the infarcted heart. These results present the tailor-made peptide scaffolds as a new generation of sustained-release biomimetic biomaterials and suggest that the use of angiogenic factors along with designer self-assembling peptides can lead to myocardial protection, sufficient angiogenesis, and improvement in cardiac function.

  5. Polymeric microparticles for sustained and local delivery of antiCD40 and antiCTLA-4 in immunotherapy of cancer

    NARCIS (Netherlands)

    Rahimian, Sima; Fransen, Marieke F.; Kleinovink, Jan Willem; Amidi, Maryam; Ossendorp, Ferry; Hennink, Wim E.

    2015-01-01

    This study investigated the feasibility of the use of polymeric microparticles for sustained and local delivery of immunomodulatory antibodies in immunotherapy of cancer. Local delivery of potent immunomodulatory antibodies avoids unwanted systemic side effects while retaining their anti-tumor

  6. Illumination devices for uniform delivery of light to the oral cavity for photodynamic therapy

    Science.gov (United States)

    Canavesi, Cristina; Cassarly, William J.; Foster, Thomas H.; Rolland, Jannick P.

    2011-10-01

    To date, the lack of light delivery mechanisms to the oral cavity remains a barrier to the treatment of oral cancer with photodynamic therapy (PDT). The greatest impediment to medical practitioners is the current need to shield the normal tissues of the oral cavity, a costly and time-consuming procedure. In this research, we present the design of illumination devices to deliver light to the oral cavity for PDT, which will facilitate administration of PDT in the clinic. The goal for such an illumination device, as indicated by our clinical collaborators at Roswell Park Cancer Institute in Buffalo, NY, is to limit exposure of healthy tissue and produce an average irradiance of 100 mW/cm2 over the treatment field, with spatial non-uniformities below 10%. Furthermore, the size of the device must be compact to allow use in the oral cavity. Our research led to the design and fabrication of two devices producing spatial non-uniformities below 6% over a treatment area of 0.25 cm2 by design. One device consisted of an appropriately-sized reflector, inspired by solar concentrators, illuminated by a cylindrical diffusing fiber optimally located within the reflector; another was a solid lightpipe with a combination of optimized tapered and straight components.

  7. Generation and delivery device for ozone gas and ozone dissolved in water

    Science.gov (United States)

    Andrews, Craig C. (Inventor); Murphy, Oliver J. (Inventor)

    2006-01-01

    The present invention provides an ozone generation and delivery system that lends itself to small scale applications and requires very low maintenance. The system includes an anode reservoir and a cathode phase separator each having a hydrophobic membrane to allow phase separation of produced gases from water. The system may be configured to operate passively with no moving parts or in a self-pressurizing manner with the inclusion of a pressure controlling device or valve in the gas outlet of the anode reservoir. The hydrogen gas, ozone gas and water containing ozone may be delivered under pressure.

  8. Sustained Subconjunctival Delivery of Infliximab Protects the Cornea and Retina Following Alkali Burn to the Eye

    Science.gov (United States)

    Zhou, Chengxin; Robert, Marie-Claude; Kapoulea, Vassiliki; Lei, Fengyang; Stagner, Anna M.; Jakobiec, Frederick A.; Dohlman, Claes H.; Paschalis, Eleftherios I.

    2017-01-01

    Purpose Tumor necrosis factor (TNF)-α is upregulated in eyes following corneal alkali injury and contributes to corneal and also retinal damage. Prompt TNF-α inhibition by systemic infliximab ameliorates retinal damage and improves corneal wound healing. However, systemic administration of TNF-α inhibitors carries risk of significant complications, whereas topical eye-drop delivery is hindered by poor ocular bioavailability and the need for patient adherence. This study investigates the efficacy of subconjunctival delivery of TNF-α antibodies using a polymer-based drug delivery system (DDS). Methods The drug delivery system was prepared using porous polydimethylsiloxane/polyvinyl alcohol composite fabrication and loaded with 85 μg of infliximab. Six Dutch-belted pigmented rabbits received ocular alkali burn with NaOH. Immediately after the burn, subconjunctival implantation of anti-TNF-α DDS was performed in three rabbits while another three received sham DDS (without antibody). Rabbits were followed with photography for 3 months. Results After 3 months, the device was found to be well tolerated by the host and the eyes exhibited less corneal damage as compared to eyes implanted with a sham DDS without drug. The low dose treatment suppressed CD45 and TNF-α expression in the burned cornea and inhibited retinal ganglion cell apoptosis and optic nerve degeneration, as compared to the sham DDS treated eyes. Immunolocalization revealed drug penetration in the conjunctiva, cornea, iris, and choroid, with residual infliximab in the DDS 3 months after implantation. Conclusions This reduced-risk biologic DDS improves corneal wound healing and provides retinal neuroprotection, and may be applicable not only to alkali burns but also to other inflammatory surgical procedures such as penetrating keratoplasty and keratoprosthesis implantation. PMID:28114570

  9. Is gentamycin delivery via sustained-release vehicles a safe and effective treatment for refractory Meniere's disease? A critical analysis of published interventional studies.

    Science.gov (United States)

    Vlastarakos, Petros V; Iacovou, Emily; Nikolopoulos, Thomas P

    2017-03-01

    The aim of this study is to review the literature on sustained-release vehicles delivering gentamycin in the inner ear of patients suffering from Meniere's disease (MD), and critically assess their respective clinical effectiveness and safety. A systematic literature review was conducted in Medline and other database sources until January 2016, along with critical analysis of pooled data. Overall, six prospective and four retrospective studies were systematically analyzed. The total number of treated patients was 320. A 2 year patient follow up was only reported in 40 % of studies. Inner ear gentamycin delivery using sustained-release vehicles is associated with improved vertigo control (strength of recommendation B), and quality of life (strength of recommendation B) in MD sufferers. In addition, dynamic-release devices seem to achieve high rates of improvement in the appearance of tinnitus (65.4 %) and aural pressure (76.2 %). By contrast, percentages of complete and partial hearing loss appear unacceptably high (31.08 and 23.38 % of patients, respectively), compared to historical data involving simple intratympanic gentamycin injections. Sustained-release vehicles for gentamycin delivery may have a role in the management of MD patients who have previously failed intratympanic gentamycin injections, or those who have already lost serviceable hearing. Their use as first line treatment over single intratympanic injections for all MD patients, who do not respond to conservative treatment should be discouraged.

  10. Constraints in animal health service delivery and sustainable improvement alternatives in North Gondar, Ethiopia

    Directory of Open Access Journals (Sweden)

    Hassen Kebede

    2014-02-01

    Full Text Available Poor livestock health services remain one of the main constraints to livestock production in many developing countries, including Ethiopia. A study was carried out in 11 districts of North Gondar, from December 2011 to September 2012, with the objective of identifying the existing status and constraints of animal health service delivery, and thus recommending possible alternatives for its sustainable improvement. Data were collected by using pre-tested questionnaires and focus group discussion. Findings revealed that 46.34% of the responding farmers had taken their animals to government veterinary clinics after initially trying treatments with local medication. More than 90.00% of the clinical cases were diagnosed solely on clinical signs or even history alone. The antibacterial drugs found in veterinary clinics were procaine penicillin (with or without streptomycin, oxytetracycline and sulphonamides, whilst albendazole, tetramisole and ivermectin were the only anthelmintics. A thermometer was the only clinical aid available in all clinics, whilst only nine (45.00% clinics had a refrigerator. In the private sector, almost 95.00% were retail veterinary pharmacies and only 41.20% fulfilled the requirement criteria set. Professionals working in the government indicated the following problems: lack of incentives (70.00%, poor management and lack of awareness (60.00% and inadequate budget (40.00%. For farmers, the most frequent problems were failure of private practitioners to adhere to ethical procedures (74.00% and lack of knowledge of animal diseases and physical distance from the service centre (50.00%. Of all responding farmers, 58.54% preferred the government service, 21.14% liked both services equally and 20.33% preferred the private service. Farmers’ indiscriminate use of drugs from the black market (23.00% was also mentioned as a problem by private practitioners. Sustainable improvement of animal health service delivery needs increased

  11. Recent advances in the administration of vaccines for infectious diseases: microneedles as painless delivery devices for mass vaccination.

    Science.gov (United States)

    Hegde, Nagendra R; Kaveri, Srinivas V; Bayry, Jagadeesh

    2011-12-01

    Despite remarkable progress in the control of infectious diseases through vaccination, better delivery systems have been poorly explored. There is renewed interest in the discovery of novel vaccines and adjuvants owing to emerging and reemerging diseases and the burden and complexity of chronic infectious diseases. Conversely, the need for rapid local, regional, mucosal or parenteral bioavailability has led to advances in delivery systems and devices. Here, we present recent developments in the field of non-invasive cutaneous delivery of vaccines for infectious diseases. Transdermal delivery using microneedles could revolutionize the way prophylactic interventions for infectious diseases are carried out in the future. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. 3D printed UV light cured polydimethylsiloxane devices for drug delivery.

    Science.gov (United States)

    Holländer, Jenny; Hakala, Risto; Suominen, Jaakko; Moritz, Niko; Yliruusi, Jouko; Sandler, Niklas

    2017-11-09

    The goal of this work was to study the printability of PDMS with a semi-solid extrusion printer in combination with the UV-assisted crosslinking technology using UV-LED light to manufacture drug containing structures. Structures with different pore sizes and different drug loadings were prepared containing prednisolone as a model drug. The work showed that it was possible to print drug-free and drug-loaded drug delivery devices of PDMS with the 3D printing technique used in this study. The required UV-curing time to get sufficient crosslinking yield and mechanical strength was minimum three minutes. The microgram drug release from the printed structures was highest for the most drug loaded structures regardless of the porosity of the devices. By altering the surface area/volume ratio it was possible to print structures with differences in the release rate. This study shows that room-temperature semi-solid extrusion printing 3D printing technique in combination with UV-LED crosslinking is an applicable method in the production of prednisolone containing PDMS devices. Both the extrusion 3D printing and the UV-crosslinking was done at room temperature, which make this manufacturing method an interesting alternative for manufacturing controlled release devices containing temperature susceptible drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Tailor-Made Pentablock Copolymer Based Formulation for Sustained Ocular Delivery of Protein Therapeutics

    Directory of Open Access Journals (Sweden)

    Sulabh P. Patel

    2014-01-01

    Full Text Available The objective of this research article is to report the synthesis and evaluation of novel pentablock copolymers for controlled delivery of macromolecules in the treatment of posterior segment diseases. Novel biodegradable PB copolymers were synthesized by sequential ring-opening polymerization. Various ratios and molecular weights of each block (polyglycolic acid, polyethylene glycol, polylactic acid, and polycaprolactone were selected for synthesis and to optimize release profile of FITC-BSA, IgG, and bevacizumab from nanoparticles (NPs and thermosensitive gel. NPs were characterized for particle size, polydispersity, entrapment efficiency, and drug loading. In vitro release study of proteins from NPs alone and composite formulation (NPs suspended in thermosensitive gel was performed. Composite formulations demonstrated no or negligible burst release with continuous near zero-order release in contrast to NPs alone. Hydrodynamic diameter of protein therapeutics and hydrophobicity of PB copolymer exhibited significant effect on entrapment efficiency and in vitro release profile. CD spectroscopy confirmed retention of structural conformation of released protein. Biological activity of released bevacizumab was confirmed by in vitro cell proliferation and cell migration assays. It can be concluded that novel PB polymers can serve a platform for sustained delivery of therapeutic proteins.

  14. Dual Cross-Linked Carboxymethyl Sago Pulp-Gelatine Complex Coacervates for Sustained Drug Delivery

    Directory of Open Access Journals (Sweden)

    Saravanan Muniyandy

    2015-06-01

    Full Text Available In the present work, we report for the first time the complex coacervation of carboxymethyl sago pulp (CMSP with gelatine for sustained drug delivery. Toluene saturated with glutaraldehyde and aqueous aluminum chloride was employed as cross-linkers. Measurements of zeta potential confirm neutralization of two oppositely charged colloids due to complexation, which was further supported by infrared spectroscopy. The coacervates encapsulated a model drug ibuprofen and formed microcapsules with a loading of 29%–56% w/w and an entrapment efficiency of 85%–93% w/w. Fresh coacervates loaded with drug had an average diameter of 10.8 ± 1.93 µm (n = 3 ± s.d.. The coacervates could encapsulate only the micronized form of ibuprofen in the absence of surfactant. Analysis through an optical microscope evidenced the encapsulation of the drug in wet spherical coacervates. Scanning electron microscopy revealed the non-spherical geometry and surface roughness of dried drug-loaded microcapsules. X-ray diffraction, differential scanning calorimetry and thermal analysis confirmed intact and crystalline ibuprofen in the coacervates. Gas chromatography indicated the absence of residual glutaraldehyde in the microcapsules. Dual cross-linked microcapsules exhibited a slower release than mono-cross-linked microcapsules and could sustain the drug release over the period of 6 h following Fickian diffusion.

  15. Engineered Hydrogels for Local and Sustained Delivery of RNA-Interference Therapies.

    Science.gov (United States)

    Wang, Leo L; Burdick, Jason A

    2017-01-01

    It has been nearly two decades since RNA-interference (RNAi) was first reported. While there are no approved clinical uses, several phase II and III clinical trials suggest the great promise of RNAi therapeutics. One challenge for RNAi therapies is the controlled localization and sustained presentation to target tissues, to both overcome systemic toxicity concerns and to enhance in vivo efficacy. One approach that is emerging to address these limitations is the entrapment of RNAi molecules within hydrogels for local and sustained release. In these systems, nucleic acids are either delivered as siRNA conjugates or within nanoparticles. A plethora of hydrogels has been implemented using these approaches, including both traditional hydrogels that have already been developed for other applications and new hydrogels developed specifically for RNAi delivery. These hydrogels have been applied to various applications in vivo, including cancer, bone regeneration, inflammation and cardiac repair. This review will examine the design and implementation of such hydrogel RNAi systems and will cover the most recent applications of these systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Preparation and Evaluation of Dexamethasone-Loaded Electrospun Nanofiber Sheets as a Sustained Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Jin Woo Lee

    2016-03-01

    Full Text Available Recently, electrospinning technology has been widely used as a processing method to make nanofiber sheets (NS for biomedical applications because of its unique features, such as ease of fabrication and high surface area. To develop a sustained dexamethasone (Dex delivery system, in this work, poly(ε-caprolactone-co-l-lactide (PCLA copolymer with controllable biodegradability was synthesized and further utilized to prepare electrospun Dex-loaded NS using water-insoluble Dex (Dex(b or water-soluble Dex (Dex(s. The Dex-NS obtained by electrospinning exhibited randomly oriented and interconnected fibrillar structures. The in vitro and in vivo degradation of Dex-NS was confirmed over a period of a few weeks by gel permeation chromatography (GPC and nuclear magnetic resonance (NMR. The evaluation of in vitro and in vivo Dex(b and Dex(s release from Dex-NS showed an initial burst of Dex(b at day 1 and, thereafter, almost the same amount of release as Dex(b for up to 28 days. In contrast, Dex(s-NS exhibited a small initial burst of Dex(s and a first-order releasing profile from Dex-NS. In conclusion, Dex-NS exhibited sustained in vitro and in vivo Dex(s release for a prolonged period, as well as controlled biodegradation of the NS over a defined treatment period.

  17. Microparticles Produced by the Hydrogel Template Method for Sustained Drug Delivery

    Science.gov (United States)

    Lu, Ying; Sturek, Michael; Park, Kinam

    2014-01-01

    Polymeric microparticles have been used widely for sustained drug delivery. Current methods of microparticle production can be improved by making homogeneous particles in size and shape, increasing the drug loading, and controlling the initial burst release. In the current study, the hydrogel template method was used to produce homogeneous poly(lactide-co-glycolide) (PLGA) microparticles and to examine formulation and process-related parameters. Poly(vinyl alcohol) (PVA) was used to make hydrogel templates. The parameters examined include PVA molecular weight, type of PLGA (as characterized by lactide content, inherent viscosity), polymer concentration, drug concentration and composition of solvent system. Three model compounds studied were risperidone, methylprednisolone acetate and paclitaxel. The ability of the hydrogel template method to produce microparticles with good conformity to template was dependent on molecular weight of PVA and viscosity of the PLGA solution. Drug loading and encapsulation efficiency were found to be influenced by PLGA lactide content, polymer concentration and composition of the solvent system. The drug loading and encapsulation efficiency were 28.7% and 82% for risperidone, 31.5% and 90% for methylprednisolone acetate, and 32.2 % and 92 % for paclitaxel, respectively. For all three drugs, release was sustained for weeks, and the in vitro release profile of risperidone was comparable to that of microparticles prepared using the conventional emulsion method. The hydrogel template method provides a new approach of manipulating microparticles. PMID:24333903

  18. Retention of in vitro and in vivo BMP-2 bioactivities in sustained delivery vehicles for bone tissue engineering

    NARCIS (Netherlands)

    Kempen, Diederik H. R.; Lu, Lichun; Hefferan, Teresa E.; Creemers, Laura B.; Maran, Avudaiappan; Classic, Kelly L.; Dhert, Wouter J. A.; Yaszemski, Michael J.

    In this study, we investigated the in vitro and in vivo biological activities of bone morphogenetic protein 2 (BMP-2) released from four sustained delivery vehicles for bone regeneration. BMP-2 was incorporated into (1) a gelatin hydrogel, (2) poly(lactic-co-glycolic acid) (PLGA) microspheres

  19. Miniaturized supercapacitors: key materials and structures towards autonomous and sustainable devices and systems

    Science.gov (United States)

    Soavi, Francesca; Bettini, Luca Giacomo; Piseri, Paolo; Milani, Paolo; Santoro, Carlo; Atanassov, Plamen; Arbizzani, Catia

    2016-09-01

    Supercapacitors (SCs) are playing a key role for the development of self-powered and self-sustaining integrated systems for different fields ranging from remote sensing, robotics and medical devices. SC miniaturization and integration into more complex systems that include energy harvesters and functional devices are valuable strategies that address system autonomy. Here, we discuss about novel SC fabrication and integration approaches. Specifically, we report about the results of interdisciplinary activities on the development of thin, flexible SCs by an additive technology based on Supersonic Cluster Beam Deposition (SCBD) to be implemented into supercapacitive electrolyte gated transistors and supercapacitive microbial fuel cells. Such systems integrate at materials level the specific functions of devices, like electric switch or energy harvesting with the reversible energy storage capability. These studies might open new frontiers for the development and application of new multifunction-energy storage elements.

  20. Cyclodextrin-erythromycin complexes as a drug delivery device for orthopedic application

    Science.gov (United States)

    Song, Wei; Yu, Xiaowei; Wang, Sunxi; Blasier, Ralph; Markel, David C; Mao, Guangzhao; Shi, Tong; Ren, Weiping

    2011-01-01

    Background Erythromycin, a hydrophobic antibiotic used to treat infectious diseases, is now gaining attention because of its anti-inflammatory effects and ability to inhibit osteoclasts formation. The aim of this study was to explore a cyclodextrin-erythromycin (CD-EM) complex for sustained treatment of orthopedic inflammation. Methods and results Erythromycin was reacted with β-cyclodextrin to form a nonhost-guest CD-EM complex using both kneading and stirring approaches. Physiochemical measurement data indicated that erythromycin and cyclodextrin formed a packing complex driven by intermolecular forces instead of a host-guest structure due to the limited space in the inner cavity of β-cyclodextrin. The CD-EM complex improved the stability of erythromycin in aqueous solution and had a longer duration of bactericidal activity than free erythromycin. Cytotoxicity and cell differentiation were evaluated in both murine MC3T3 preosteoblast cells and RAW 264.7 murine macrophage cells. The CD-EM complex was noncytotoxic and showed significant inhibition of osteoclast formation but had little effect on osteoblast viability and differentiation. Conclusion These attributes are especially important for the delivery of an adequate amount of erythromycin to the site of periprosthetic inflammation and reducing local inflammation in a sustained manner. PMID:22228990

  1. Formulating nanoparticles by flash nanoprecipitation for drug delivery and sustained release

    Science.gov (United States)

    Liu, Ying

    This dissertation provides a fundamental understanding of the process for generating nanoparticles with controlled size distribution and of predicting nanoparticle stability for drug delivery and sustained release. We developed and characterized a novel technology to generate organic and inorganic nanoparticles protected by biocompatible and biodegradable polymers with precisely controlled size and size distribution. Computational fluid mechanics (CFD) together with experimental results provided details of the micromixing in the mixer. The particle size dependence on Reynolds number and supersaturation was illustrated. The study of the fundamental mass transfer phenomena leading to Ostwald ripening enables quantitative prediction of the time evolution of nanoparticles with monodistribution and relatively broader multi-distribution using beta-carotene and polystyrene-b-poly(ethylene oxide) (PS-b-PEO) as a model system. Negatively charged latex particles were used to exam the attachment of the diblock copolymer, PS-b-PEO, on the surface. The stability provided by the Columbic repulsion was replaced by steric stabilization. The attachment of the block copolymers on the surface of the colloids depends on the flow field, i.e. Reynolds number, of the mixing process. The slow degradation of poly(epsilon-caprolactone) (PCL) and poly(gamma-methyl-epsilon-caprolactone) (PMCL) was demonstrated. The slow degradation ensures long-term stability and long-term blood circulation of the polymeric nanoparticles. As a practical application, we formulate the anti-tuberculosis drug, rifampicin, into nanoparticles by conjugation to other hydrophobic molecules (such as vitamin E, PCL and 2-ethylhexyl vinyl ether) by pH sensitive cleavable chemical bonds to increase the drug loading, return stability of the nanoparticle suspension, and control drug release. The in vitro release profiles were provided by using HPLC and E.coli growth inhibition on LB agar plates. The prodrug nanoparticle

  2. Hydrogel-swelling driven delivery device for corrosion resistance of metal in water.

    Science.gov (United States)

    Gu, Yu; Yang, Li-Ming; Chen, Jie; Wang, Ling-Ling; Chen, Bin

    2015-01-01

    Corrosion on steel and copper pipes in industry can trigger pollution and weakness due to undesired chemical and biochemical reactions. Too much or too little inhibitor can decrease its efficiency, even causing waste and pollution. In this contribution, an innovative delivery device driven by hydrogel swelling, mainly consisting of a semi-permeable membrane, a hydrogel-swelling force drive and a release orifice, was developed to control the release of inhibitor in a water system at a constant rate, leading the amount of inhibitor to maintain a proper concentration. The effects of hydrogel mass and orifice dimension on release property were studied for controlling release rate. Moreover, a weight loss experiment on carbon steels was carried out to show the incredible anti-corrosion function of the system.

  3. Natural gums as sustained release carriers: development of gastroretentive drug delivery system of ziprasidone HCl

    Directory of Open Access Journals (Sweden)

    AJ Rajamma

    2012-10-01

    Full Text Available Abstract Background Objective of this study is to show the potential use of natural gums in the development of drug delivery systems. Therefore in this work gastro retentive tablet formulations of ziprasidone HCl were developed using simplex lattice design considering concentration of okra gum, locust bean gum and HPMC K4M as independent variables. A response surface plot and multiple regression equations were used to evaluate the effect of independent variables on hardness, flag time, floating time and drug release for 1 h, 2 h, and 8 h and for 24 h. A checkpoint batch was also prepared by considering the constraints and desirability of optimized formulation to improve its in vitro performance. Significance of result was analyzed using ANOVA and p was considered statistically significant. Results Formulation chiefly contains locust bean gum found to be favorable for hardness and floatability but combined effect of three variables was responsible for the sustained release of drug. The in vitro drug release data of check point batch (F8 was found to be sustained well compared to the most satisfactory formulation (F7 of 7 runs. The ‘n’ value was found to be between 0.5 and 1 suggesting that release of drug follows anomalous (non-fickian diffusion mechanism indicating both diffusion and erosion mechanism from these natural gums. Predicted results were almost similar to the observed experimental values indicating the accuracy of the design. In vivo floatability test indicated non adherence to the gastric mucosa and tablets remain buoyant for more than 24 h. Conclusions Study showed these eco-friendly natural gums can be considered as promising SR polymers.

  4. Deformable microparticles with multiple functions for drug delivery and device testing

    Science.gov (United States)

    Thula, Taili T.

    Since the HIV epidemic of the 1990s, researchers have attempted to develop a red blood cell analog. Even though some of these substitutes are now in Phase III of clinical trials, their use is limited by side effects and short half-life in the human body. As a result, there is still a need for an effective erythrocyte analog with minimum immunogenic and side effects, so that it can be used for multiple applications. Finding new approaches to develop more efficient blood substitutes will not only bring valuable advances in the clinical approach, but also in the area of in vitro testing of medical devices. We examined the feasibility of creating a deformable multi-functional, biodegradable, biocompatible particle for applications in drug delivery and device testing. As a preliminary evaluation, we synthesized different types of microcapsules using natural and synthetic polymers, various cross-linking agents, and diverse manufacturing techniques. After fully characterizing of each system, we determined the most promising red blood cell analog in terms of deformability, stability and toxicity. We also examined the encapsulation and release of bovine serum albumin (BSA) within these deformable particles. After removal of cross-linkers, zinc- and copper-alginate microparticles surrounded by multiple polyelectrolyte layers of chitosan oligosaccharide and alginate were deformable and remained stable under physiological pressures applied by the micropipette technique. In addition, multiple coatings decreased toxicity of heavy-metal crosslinked particles. BSA encapsulation and release from chitosan-alginate microspheres were contingent on the crosslinker and number of polyelectrolyte coatings, respectively. Further rheological studies are needed to determine how closely these particles simulate the behavior of erythrocytes. Also, studies on the encapsulation and release of different proteins, including hemoglobin, are needed to establish the desired controlled release of

  5. ZnO Nano-Rod Devices for Intradermal Delivery and Immunization.

    Science.gov (United States)

    Nayak, Tapas R; Wang, Hao; Pant, Aakansha; Zheng, Minrui; Junginger, Hans; Goh, Wei Jiang; Lee, Choon Keong; Zou, Shui; Alonso, Sylvie; Czarny, Bertrand; Storm, Gert; Sow, Chorng Haur; Lee, Chengkuo; Pastorin, Giorgia

    2017-06-15

    Intradermal delivery of antigens for vaccination is a very attractive approach since the skin provides a rich network of antigen presenting cells, which aid in stimulating an immune response. Numerous intradermal techniques have been developed to enhance penetration across the skin. However, these methods are invasive and/or affect the skin integrity. Hence, our group has devised zinc oxide (ZnO) nano-rods for non-destructive drug delivery. Chemical vapour deposition was used to fabricate aligned nano-rods on ZnO pre-coated silicon chips. The nano-rods' length and diameter were found to depend on the temperature, time, quality of sputtered silicon chips, etc. Vertically aligned ZnO nano-rods with lengths of 30-35 µm and diameters of 200-300 nm were selected for in vitro human skin permeation studies using Franz cells with Albumin-fluorescein isothiocyanate (FITC) absorbed on the nano-rods. Fluorescence and confocal studies on the skin samples showed FITC penetration through the skin along the channels formed by the nano-rods. Bradford protein assay on the collected fluid samples indicated a significant quantity of Albumin-FITC in the first 12 h. Low antibody titres were observed with immunisation on Balb/c mice with ovalbumin (OVA) antigen coated on the nano-rod chips. Nonetheless, due to the reduced dimensions of the nano-rods, our device offers the additional advantage of excluding the simultaneous entrance of microbial pathogens. Taken together, these results showed that ZnO nano-rods hold the potential for a safe, non-invasive, and painless intradermal drug delivery.

  6. ZnO Nano-Rod Devices for Intradermal Delivery and Immunization

    Directory of Open Access Journals (Sweden)

    Tapas R. Nayak

    2017-06-01

    Full Text Available Intradermal delivery of antigens for vaccination is a very attractive approach since the skin provides a rich network of antigen presenting cells, which aid in stimulating an immune response. Numerous intradermal techniques have been developed to enhance penetration across the skin. However, these methods are invasive and/or affect the skin integrity. Hence, our group has devised zinc oxide (ZnO nano-rods for non-destructive drug delivery. Chemical vapour deposition was used to fabricate aligned nano-rods on ZnO pre-coated silicon chips. The nano-rods’ length and diameter were found to depend on the temperature, time, quality of sputtered silicon chips, etc. Vertically aligned ZnO nano-rods with lengths of 30–35 µm and diameters of 200–300 nm were selected for in vitro human skin permeation studies using Franz cells with Albumin-fluorescein isothiocyanate (FITC absorbed on the nano-rods. Fluorescence and confocal studies on the skin samples showed FITC penetration through the skin along the channels formed by the nano-rods. Bradford protein assay on the collected fluid samples indicated a significant quantity of Albumin-FITC in the first 12 h. Low antibody titres were observed with immunisation on Balb/c mice with ovalbumin (OVA antigen coated on the nano-rod chips. Nonetheless, due to the reduced dimensions of the nano-rods, our device offers the additional advantage of excluding the simultaneous entrance of microbial pathogens. Taken together, these results showed that ZnO nano-rods hold the potential for a safe, non-invasive, and painless intradermal drug delivery.

  7. Characterization of a poly-epsilon-caprolactone polymeric drug delivery device built by selective laser sintering.

    Science.gov (United States)

    Leong, K F; Wiria, F E; Chua, C K; Li, S H

    2007-01-01

    Selective Laser Sintering (SLS), an established Rapid Prototyping (RP) process, is investigated for building controlled drug delivery devices (DDD). The drug and its matrix in a powder form were first mixed mechanically before being sintered on the SLS. Each cylindrical DDD is designed with a number of concentric rings separated from each other by a characteristic 'wall' created by the laser of the SLS. These rings act as diffusion obstacles to control the rate of release. Poly-epsilon-caprolactone (PCL) was used as the matrix and Methylene Blue (MB) as the drug model. Samples were built, characterized and tested for homogeneity using Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared Spectrophotometry (FTIR). Experimental results show that the matrices fabricated are not affected by sintering and the polymer and drug model are evenly distributed throughout the matrix. The initial burst effect has been reduced by the increase of the numbers of rings. The linear curve using the Higuchi equation confirmed that the DDD matrix release profile is by diffusion. These results show that the DDD matrix design has promising potential for application in controlled release drug delivery.

  8. A qualitative study examining the sustainability of shared care in the delivery of palliative care services in the community.

    Science.gov (United States)

    Demiglio, Lily; Williams, Allison M

    2013-08-29

    This paper focuses on the sustainability of existing palliative care teams that provide home-based care in a shared care model. For the purposes of this study, following Evashwick and Ory (2003), sustainability is understood and approached as the ability to continue the program over time. Understanding factors that influence the sustainability of teams and ways to mitigate these factors is paramount to improving the longevity and quality of service delivery models of this kind. Using qualitative data collected in interviews, the aim of this study is twofold: (1) to explore the factors that affect the sustainability of the teams at three different scales, and; (2) based on the results of this study, to propose a set of recommendations that will contribute to the sustainability of PC teams. Sustainability was conceptualized from two angles: internal and external. An overview of external sustainability was provided and the merging of data from all participant groups showed that the sustainability of teams was largely dependent on actors and organizations at the local (community), regional (Local Health Integration Network or LHIN) and provincial scales. The three scales are not self-contained or singular entities but rather are connected. Integration and collaboration within and between scales is necessary, as community capacity will inevitably reach its threshold without support of the province, which provides funding to the LHIN. While the community continues to advocate for the teams, in the long-term, they will need additional supports from the LHIN and province. The province has the authority and capacity to engrain its support for teams through a formal strategy. The recommendations are presented based on scale to better illustrate how actors and organizations could move forward. This study may inform program and policy specific to strategic ways to improve the provision of team-based palliative home care using a shared care model, while simultaneously providing

  9. Composite CD-MOF nanocrystals-containing microspheres for sustained drug delivery.

    Science.gov (United States)

    Li, Haiyan; Lv, Nana; Li, Xue; Liu, Botao; Feng, Jing; Ren, Xiaohong; Guo, Tao; Chen, Dawei; Fraser Stoddart, J; Gref, Ruxandra; Zhang, Jiwen

    2017-06-08

    Metal-organic frameworks (MOFs), which are typically embedded in polymer matrices as composites, are emerging as a new class of carriers for sustained drug delivery. Most of the MOFs and the polymers used so far in these composites, however, are not pharmaceutically acceptable. In the investigation reported herein, composites of γ-cyclodextrin (γ-CD)-based MOFs (CD-MOFs) and polyacrylic acid (PAA) were prepared by a solid in oil-in-oil (s/o/o) emulsifying solvent evaporation method. A modified hydrothermal protocol has been established which produces efficiently at 50 °C in 6 h micron (5-10 μm) and nanometer (500-700 nm) diameter CD-MOF particles of uniform size with smooth surfaces and powder X-ray diffraction patterns that are identical with those reported in the literature. Ibuprofen (IBU) and Lansoprazole (LPZ), both insoluble in water and lacking in stability, were entrapped with high drug loading in nanometer-sized CD-MOFs by co-crystallisation (that is more effective than impregnation) without causing MOF crystal degradation during the loading process. On account of the good dispersion of drug-loaded CD-MOF nanocrystals inside polyacrylic acid (PAA) matrices and the homogeneous distribution of the drug molecules within these crystals, the composite microspheres exhibit not only spherical shapes and sustained drug release over a prolonged period of time, but they also demonstrate reduced cell toxicity. The cumulative release rate for IBU (and LPZ) follows the trend: IBU-γ-CD complex microspheres (ca. 80% in 2 h) > IBU microspheres > IBU-CD-MOF/PAA composite microspheres (ca. 50% in 24 h). Importantly, no burst release of IBU (and LPZ) was observed from the CD-MOF/PAA composite microspheres, suggesting an even distribution of the drug as well as strong drug carrier interactions inside the CD-MOF. In summary, these composite microspheres, composed of CD-MOF nanocrystals embedded in a biocompatible polymer (PAA) matrix, constitute an efficient and

  10. Sustained ocular delivery of brimonidine tartrate using ion activated in situ gelling system.

    Science.gov (United States)

    Geethalakshmi, A; Karki, Roopa; Jha, Sajal Kumar; Venkatesh, D P; Nikunj, B

    2012-03-01

    The poor bioavailability and therapeutic response exhibited by conventional eye drops due to rapid precorneal elimination of the drug may be overcome by the use of an in situ gelling systems that are instilled as drops into the eye and undergo a sol-to-gel transition in the cul-de-sac which improves patient compliance as the dosage regimen is one drop of the dosage form twice a day. The loss of drug overcomes due to the immediate gel formation between the eye membrane and the drug being entrapped simultaneously in sol-gel transition in the cul de sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antiglaucomal agent, brimonidine tartrate based on the concept of ion-activated in situ gelation. Gelrite was used as the gelling agent, which gels in the presence of mono or divalent cations present in the lacrimal fluid. The formulations were evaluated for clarity, pH measurement, gelling capacity, drug content estimation, rheological study, in-vitro diffusion study, antibacterial activity, isotonicity testing, eye irritation testing. In the developed formulations Gelrite Brimonidine-3 (GB3) exhibited sustained release of drug from formulation over a period of 8 hrs thus increasing residence time of the drug, non-irritating with no ocular damage or abnormal clinical signs to the cornea, iris or conjunctiva, stable and sterile. These results demonstrate that the developed system is an alternative to conventional ophthalmic drops, with better patient compliance, and is industrially oriented and economical.

  11. A high-speed scintillation-based electronic portal imaging device to quantitatively characterize IMRT delivery.

    Science.gov (United States)

    Ranade, Manisha K; Lynch, Bart D; Li, Jonathan G; Dempsey, James F

    2006-01-01

    We have developed an electronic portal imaging device (EPID) employing a fast scintillator and a high-speed camera. The device is designed to accurately and independently characterize the fluence delivered by a linear accelerator during intensity modulated radiation therapy (IMRT) with either step-and-shoot or dynamic multileaf collimator (MLC) delivery. Our aim is to accurately obtain the beam shape and fluence of all segments delivered during IMRT, in order to study the nature of discrepancies between the plan and the delivered doses. A commercial high-speed camera was combined with a terbium-doped gadolinium-oxy-sulfide (Gd2O2S:Tb) scintillator to form an EPID for the unaliased capture of two-dimensional fluence distributions of each beam in an IMRT delivery. The high speed EPID was synchronized to the accelerator pulse-forming network and gated to capture every possible pulse emitted from the accelerator, with an approximate frame rate of 360 frames-per-second (fps). A 62-segment beam from a head-and-neck IMRT treatment plan requiring 68 s to deliver was recorded with our high speed EPID producing approximately 6 Gbytes of imaging data. The EPID data were compared with the MLC instruction files and the MLC controller log files. The frames were binned to provide a frame rate of 72 fps with a signal-to-noise ratio that was sufficient to resolve leaf positions and segment fluence. The fractional fluence from the log files and EPID data agreed well. An ambiguity in the motion of the MLC during beam on was resolved. The log files reported leaf motions at the end of 33 of the 42 segments, while the EPID observed leaf motions in only 7 of the 42 segments. The static IMRT segment shapes observed by the high speed EPID were in good agreement with the shapes reported in the log files. The leaf motions observed during beam-on for step-and-shoot delivery were not temporally resolved by the log files.

  12. Satisfaction with assistive technology device in relation to the service delivery process-A systematic review.

    Science.gov (United States)

    Larsson Ranada, Åsa; Lidström, Helene

    2017-09-11

    The service delivery process (SDP) of assistive technology devices (ATDs) is attracting interest, as the provision of ATDs is critical for the independence and participation in society of individuals with disabilities. The purpose of the current study was to investigate what impact the SDP has on satisfaction with ATDs in individuals with disabilities in relation to everyday activities. A systematic literature review was conducted, which resulted in 53 articles included. The results showed that there are factors in almost all the different steps of the SDP that affect the satisfaction with of the devices, which can lead to underutilization and abandonment of ATDs. Only a few studies have been conducted with a design robust enough to generalize the results; therefore, more research is needed. Therefore, the conclusion is the SDP as a whole contributes to the satisfaction with and usability of ATDs in individuals with disability in relation to achieving the desired goals of participation in everyday activities, for the articles included must be deemed as moderate. A client-centred approach in the process is advocated, and was found to be an important factor for an effective SDP and satisfied users.

  13. Wearable/disposable sweat-based glucose monitoring device with multistage transdermal drug delivery module

    Science.gov (United States)

    Lee, Hyunjae; Song, Changyeong; Hong, Yong Seok; Kim, Min Sung; Cho, Hye Rim; Kang, Taegyu; Shin, Kwangsoo; Choi, Seung Hong; Hyeon, Taeghwan; Kim, Dae-Hyeong

    2017-01-01

    Electrochemical analysis of sweat using soft bioelectronics on human skin provides a new route for noninvasive glucose monitoring without painful blood collection. However, sweat-based glucose sensing still faces many challenges, such as difficulty in sweat collection, activity variation of glucose oxidase due to lactic acid secretion and ambient temperature changes, and delamination of the enzyme when exposed to mechanical friction and skin deformation. Precise point-of-care therapy in response to the measured glucose levels is still very challenging. We present a wearable/disposable sweat-based glucose monitoring device integrated with a feedback transdermal drug delivery module. Careful multilayer patch design and miniaturization of sensors increase the efficiency of the sweat collection and sensing process. Multimodal glucose sensing, as well as its real-time correction based on pH, temperature, and humidity measurements, maximizes the accuracy of the sensing. The minimal layout design of the same sensors also enables a strip-type disposable device. Drugs for the feedback transdermal therapy are loaded on two different temperature-responsive phase change nanoparticles. These nanoparticles are embedded in hyaluronic acid hydrogel microneedles, which are additionally coated with phase change materials. This enables multistage, spatially patterned, and precisely controlled drug release in response to the patient’s glucose level. The system provides a novel closed-loop solution for the noninvasive sweat-based management of diabetes mellitus. PMID:28345030

  14. Characterizing Thermal Augmentation of Convection-Enhanced Drug Delivery with the Fiberoptic Microneedle Device

    Directory of Open Access Journals (Sweden)

    R. Lyle Hood

    2015-09-01

    Full Text Available Convection-enhanced delivery (CED is a promising technique leveraging pressure-driven flow to increase penetration of infused drugs into interstitial spaces. We have developed a fiberoptic microneedle device for inducing local sub-lethal hyperthermia to further improve CED drug distribution volumes, and this study seeks to quantitatively characterize this approach in agarose tissue phantoms. Infusions of dye were conducted in 0.6% (w/w agarose tissue phantoms with isothermal conditions at 15 °C, 20 °C, 25 °C, and 30 °C. Infusion metrics were quantified using a custom shadowgraphy setup and image-processing algorithm. These data were used to build an empirical predictive temporal model of distribution volume as a function of phantom temperature. A second set of proof-of-concept experiments was conducted to evaluate a novel fiberoptic device capable of generating local photothermal heating during fluid infusion. The isothermal infusions showed a positive correlation between temperature and distribution volume, with the volume at 30 °C showing a 7-fold increase at 100 min over the 15 °C isothermal case. Infusions during photothermal heating (1064 nm at 500 mW showed a similar effect with a 3.5-fold increase at 4 h over the control (0 mW. These results and analyses serve to provide insight into and characterization of heat-mediated enhancement of volumetric dispersal.

  15. Approaches in topical ocular drug delivery and developments in the use of contact lenses as drug-delivery devices.

    Science.gov (United States)

    Mehta, Prina; Haj-Ahmad, Rita; Al-Kinani, Ali; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G; Ahmad, Zeeshan

    2017-07-01

    Drug-delivery approaches have diversified over the last two decades with the emergence of nanotechnologies, smart polymeric systems and multimodal functionalities. The intended target for specific treatment of disease is the key defining developing parameter. One such area which has undergone significant advancements relates to ocular delivery. This has been expedited by the development of material advancement, mechanistic concepts and through the deployment of advanced process technologies. This review will focus on the developments within lens-based drug delivery while touching on conventional and current methods of topical ocular drug delivery. A summary table will provide quick reference to note the key findings in this area. In addition, the review also elucidates current theranostic and diagnostic approaches based on ocular lenses.

  16. Approaches in topical ocular drug delivery and developments in the use of contact lenses as drug-delivery devices

    OpenAIRE

    Mehta, P.; Haj-Ahmad, R.; Al-Kinani, Ali; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.

    2017-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Drug-delivery approaches have diversified over the last two decades with the emergence of nanotechnologies, smart polymeric systems and multimodal functionalities. The intended target for specific treatment of disease is the key defining developing parameter. One such area which has undergone significant advancements relates to ocular delivery....

  17. Inhaled pulmonary vasodilators for persistent pulmonary hypertension of the newborn: safety issues relating to drug administration and delivery devices

    Directory of Open Access Journals (Sweden)

    Cosa N

    2016-04-01

    Full Text Available Nathan Cosa,1 Edward Costa Jr2 1Department of Respiratory Care, Banner Desert Medical Center, Cardon Children's Medical Center, Mesa, AZ, 2Department of Medical Affairs, Mallinckrodt Pharmaceuticals, Hampton, NJ, USA Abstract: Treatment for persistent pulmonary hypertension of the newborn (PPHN aims to reduce pulmonary vascular resistance while maintaining systemic vascular resistance. Selective pulmonary vasodilation may be achieved by targeting pulmonary-specific pathways or by delivering vasodilators directly to the lungs. Abrupt withdrawal of a pulmonary vasodilator can cause rebound pulmonary hypertension. Therefore, use of consistent delivery systems that allow for careful monitoring of drug delivery is important. This manuscript reviews published studies of inhaled vasodilators used for treatment of PPHN and provides an overview of safety issues associated with drug delivery and delivery devices as they relate to the risk of rebound pulmonary hypertension. Off-label use of aerosolized prostacyclins and an aerosolized prostaglandin in neonates with PPHN has been reported; however, evidence from large randomized clinical trials is lacking. The amount of a given dose of aerosolized drug that is actually delivered to the lungs is often unknown, and the actual amount of drug deposited in the lungs can be affected by several factors, including patient size, nebulizer used, and placement of the nebulizer within the breathing circuit. Inhaled nitric oxide (iNO is the only pulmonary vasodilator approved by the US Food and Drug Administration for the treatment of PPHN. The iNO delivery device, INOmax DSIR®, is designed to constantly monitor NO, NO2, and O2 deliveries and is equipped with audible and visual alarms to alert providers of abrupt discontinuation and incorrect drug concentration. Other safety features of this device include two independent backup delivery systems, a backup drug cylinder, a battery that provides up to 6 hours of

  18. Technological innovation in spinal cord stimulation: use of a newly developed delivery device for introduction of spinal cord stimulation leads.

    Science.gov (United States)

    Logé, David; De Coster, Olivier; Washburn, Stephanie

    2012-07-01

    The use of multiple cylindrical leads and multicolumn and single column paddle leads in spinal cord stimulation offers many advantages over the use of a single cylindrical lead. Despite these advantages, placement of multiple cylindrical leads or a paddle lead requires a more invasive surgical procedure. Thus, the ideal situation for lead delivery would be percutaneous insertion of a paddle lead or multiple cylindrical leads. This study evaluated the feasibility and safety of percutaneous delivery of S-Series paddle leads using a new delivery device called the Epiducer lead delivery system (all St. Jude Medical Neuromodulation Division, Plano, TX, USA). This uncontrolled, open-label, prospective, two-center study approved by the AZ St. Lucas (Ghent) Ethics Committee evaluated procedural aspects of implantation of an S-Series paddle lead using the Epiducer lead delivery system and any adverse events relating to the device. Efficacy data during the patent's 30-day trial also were collected.   Data from 34 patients were collected from two investigational sites. There were no adverse events related to the Epiducer lead delivery system. The device was inserted at an angle of either 20°-30° or 30°-40° and was entered into the epidural space at T12/L1 in most patients. The S-Series paddle lead was advanced four vertebral segments in more than 50% of patients. The average (±standard deviation [SD]) time it took to place the Epiducer lead delivery system was 8.7 (±5.0) min. The average (+SD) patient-reported pain relief was 78.8% (+24.1%). This study suggests the safe use of the Epiducer lead delivery system for percutaneous implantation and advancement of the S-Series paddle lead in 34 patients. © 2012 International Neuromodulation Society.

  19. Surface engineering of porous silicon microparticles for intravitreal sustained delivery of rapamycin.

    Science.gov (United States)

    Nieto, Alejandra; Hou, Huiyuan; Moon, Sang Woong; Sailor, Michael J; Freeman, William R; Cheng, Lingyun

    2015-01-22

    To understand the relationship between rapamycin loading/release and surface chemistries of porous silicon (pSi) to optimize pSi-based intravitreal delivery system. Three types of surface chemical modifications were studied: (1) pSi-COOH, containing 10-carbon aliphatic chains with terminal carboxyl groups grafted via hydrosilylation of undecylenic acid; (2) pSi-C12, containing 12-carbon aliphatic chains grafted via hydrosilylation of 1-dodecene; and (3) pSiO2-C8, prepared by mild oxidation of the pSi particles followed by grafting of 8-hydrocarbon chains to the resulting porous silica surface via a silanization. The efficiency of rapamycin loading follows the order (micrograms of drug/milligrams of carrier): pSiO2-C8 (105 ± 18) > pSi-COOH (68 ± 8) > pSi-C12 (36 ± 6). Powder X-ray diffraction data showed that loaded rapamycin was amorphous and dynamic drug-release study showed that the availability of the free drug was increased by 6-fold (compared with crystalline rapamycin) by using pSiO2-C8 formulation (P = 0.0039). Of the three formulations in this study, pSiO2-C8-RAP showed optimal performance in terms of simultaneous release of the active drug and carrier degradation, and drug-loading capacity. Released rapamycin was confirmed with the fingerprints of the mass spectrometry and biologically functional as the control of commercial crystalline rapamycin. Single intravitreal injections of 2.9 ± 0.37 mg pSiO2-C8-RAP into rabbit eyes resulted in more than 8 weeks of residence in the vitreous while maintaining clear optical media and normal histology of the retina in comparison to the controls. Porous silicon-based rapamycin delivery system using the pSiO2-C8 formulation demonstrated good ocular compatibility and may provide sustained drug release for retina. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  20. Dual-functional Polyurea Microcapsules for Chronic Wound Care Dressings: Sustained Drug Delivery and Non-leaching Infection Control

    Science.gov (United States)

    He, Wei

    A new design of dual-functional polyurea microcapsules was proposed for chronic wound dressings to provide both non-leaching infection control and sustained topical drug delivery functionalities. Quaternary ammonium functionalized polyurea microcapsules (MCQs) were synthesized under mild conditions through an interfacial crosslinking reaction between branched polyethylenimine (PEI) and 2,4-toluene diisocyanate (TDI) in a dimethylformamide/cyclohexane emulsion. An in-situ modification method was developed to endow non-leaching surface antimicrobial properties to MCQs via bonding antimicrobial surfactants to surface isocyanate residues on the polyurea shells. The resultant robust MCQs with both non-leaching antimicrobial properties and sustained drug releasing properties have potential applications in medical textiles, such as chronic wound dressings, for infection control and drug delivery.

  1. The effect of sucralose on flavor sweetness in electronic cigarettes varies between delivery devices.

    Science.gov (United States)

    Rosbrook, Kathryn; Erythropel, Hanno C; DeWinter, Tamara M; Falinski, Mark; O'Malley, Stephanie; Krishnan-Sarin, Suchitra; Anastas, Paul T; Zimmerman, Julie B; Green, Barry G

    2017-01-01

    The appeal of sweet electronic cigarette flavors makes it important to identify the chemical compounds that contribute to their sweetness. While volatile chemicals that produce sweet aromas have been identified in e-liquids, there are no published reports of sugars or artificial sweeteners in commercial e-liquids. However, the sweetener sucralose is marketed as an e-liquid additive to commercial flavors. The primary aims of the study were to determine if sucralose is delivered in sufficient concentration in the inhaled aerosol to enhance flavor sweetness, and whether the amount delivered depends on the e-liquid delivery system. Thirty-two adult smokers rated flavor intensity, sweetness, harshness and liking/disliking for 4 commercial flavors with and without sucralose (1%) using 2 e-cigarette delivery systems (cartridge and tank). Participants alternately vaped normally or with the nose pinched closed to block perception of volatile flavor components via olfaction. LC/MS was used to measure the concentration of sucralose in the e-liquid aerosols using a device that mimicked vaping. Sweetness and flavor intensity were perceived much more strongly when olfaction was permitted. The contribution of sucralose to sweetness was significant only for the cartridge system, and the chemical analysis showed that the concentration of sucralose in the aerosol was higher when the cartridge was used. Together these findings indicate that future regulation of sweet flavor additives should focus first on the volatile constituents of e-liquids with the recognition that artificial sweeteners may also contribute to flavor sweetness depending upon e-cigarette design.

  2. The effect of sucralose on flavor sweetness in electronic cigarettes varies between delivery devices.

    Directory of Open Access Journals (Sweden)

    Kathryn Rosbrook

    Full Text Available The appeal of sweet electronic cigarette flavors makes it important to identify the chemical compounds that contribute to their sweetness. While volatile chemicals that produce sweet aromas have been identified in e-liquids, there are no published reports of sugars or artificial sweeteners in commercial e-liquids. However, the sweetener sucralose is marketed as an e-liquid additive to commercial flavors. The primary aims of the study were to determine if sucralose is delivered in sufficient concentration in the inhaled aerosol to enhance flavor sweetness, and whether the amount delivered depends on the e-liquid delivery system. Thirty-two adult smokers rated flavor intensity, sweetness, harshness and liking/disliking for 4 commercial flavors with and without sucralose (1% using 2 e-cigarette delivery systems (cartridge and tank. Participants alternately vaped normally or with the nose pinched closed to block perception of volatile flavor components via olfaction. LC/MS was used to measure the concentration of sucralose in the e-liquid aerosols using a device that mimicked vaping. Sweetness and flavor intensity were perceived much more strongly when olfaction was permitted. The contribution of sucralose to sweetness was significant only for the cartridge system, and the chemical analysis showed that the concentration of sucralose in the aerosol was higher when the cartridge was used. Together these findings indicate that future regulation of sweet flavor additives should focus first on the volatile constituents of e-liquids with the recognition that artificial sweeteners may also contribute to flavor sweetness depending upon e-cigarette design.

  3. Application of gas-cooled Accelerator Driven System (ADS) transmutation devices to sustainable nuclear energy development

    Energy Technology Data Exchange (ETDEWEB)

    Abanades, A., E-mail: abanades@etsii.upm.es [ETSII/Universidad Politecnica de Madrid, J.Gutierrez Abascal, 2-28006 Madrid (Spain); Garcia, C.; Garcia, L. [Instituto Superior de Tecnologia y Ciencias Aplicadas. Quinta de los, Molinos, Ave. Salvador Allende y Luaces, Ciudad de la Habana, CP 10400, Apartado Postal 6163 (Cuba); Escriva, A.; Perez-Navarro, A. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia, C.P. 46022 Valencia (Spain); Rosales, J. [Instituto Superior de Tecnologia y Ciencias Aplicadas. Quinta de los, Molinos, Ave. Salvador Allende y Luaces, Ciudad de la Habana, CP 10400, Apartado Postal 6163 (Cuba)

    2011-06-15

    Highlights: > Utilization of Accelerator Driven System (ADS) for Hydrogen production. > Evaluation of the potential use of gas-cooled ADS for a sustainable use of Uranium resources by transmutation of nuclear wastes, electricity and Hydrogen production. > Application of the Sulfur-Iodine thermochemical process to subcritical systems. > Application of CINDER90 to calculate burn-up in subcritical systems. - Abstract: The conceptual design of a pebble bed gas-cooled transmutation device is shown with the aim to evaluate its potential for its deployment in the context of the sustainable nuclear energy development, which considers high temperature reactors for their operation in cogeneration mode, producing electricity, heat and Hydrogen. As differential characteristics our device operates in subcritical mode, driven by a neutron source activated by an accelerator that adds clear safety advantages and fuel flexibility opening the possibility to reduce the nuclear stockpile producing energy from actual LWR irradiated fuel with an efficiency of 45-46%, either in the form of Hydrogen, electricity, or both.

  4. Development of a Poly-ε-Lysine Contact Lens as a Drug Delivery Device for the Treatment of Fungal Keratitis.

    Science.gov (United States)

    Gallagher, Andrew G; McLean, Keri; Stewart, Rosalind M K; Wellings, Don A; Allison, Heather E; Williams, Rachel L

    2017-09-01

    The purpose of this study was to develop a more efficient drug delivery device to overcome the limitations of current drop therapy for the treatment of fungal keratitis. Amphotericin B (AmpB), 0 to 30 μg/mL, was associated with a poly-ε-lysine (pεK) hydrogel. Fungicidal effect against Candida albicans was assessed at 18 and 42 hours by optical density (OD600) and growth on agar. Tear film dilution effect was mimicked by storage of AmpB pεK gels in 3.4 mL sterile PBS for 24 hours prior to fungal incubation. Drug elution over 96 hours was evaluated by HPLC, and drug stability was tested while associated with the gel by OD600 up to 48 hours. Lack of cytotoxicity toward the HCE-T corneal epithelial cell line was assessed over 7 days. AmpB pεK gels show fungicidal activity in normal conditions (0.057 OD600, SD 0.003, P < 0.005) and in the presence of horse serum (0.048 OD600, SD 0.028 P < 0.005) at 18 hours. The drug release profile was above therapeutic levels (0.188 μg/mL) for up to 72 hours. Tear dilution had no significant effect at higher concentrations of AmpB (3 to 10 μg/mL). AmpB pεK gels were not cytotoxic to the HCE-T cell line. We demonstrated that AmpB pεK gels confer sustained therapeutic antifungal activity for at least 48 hours without corneal epithelial cell line cytotoxicity, suggesting their potential for in vivo use as an antifungal bandage contact lens. This could avoid the need for intensive topical medication in the treatment of fungal keratitis.

  5. Dendrimer-like assemblies based on organoclays as multi-host system for sustained drug delivery.

    Science.gov (United States)

    Li, Wei; Sun, Lili; Pan, Lijun; Lan, Zuopin; Jiang, Tao; Yang, Xiaolan; Luo, Jianchun; Li, Ronghua; Tan, Liqing; Zhang, Shurong; Yu, Mingan

    2014-11-01

    Chemical modification of nanoclay will ensure further progress on these materials. In this work, we show that montmorillonite (MTM) nanosheets can be modified with β-cyclodextrin (CD) via a nucleophilic substitution reaction between mono-6-(p-toluenesulfonyl)-6-deoxy-β-CD and an amino group of 3-aminopropyltriethoxysilane (APTES)-functionalized MTM. The resulting MTM-APTES-CD can be further self-assembled into dendrimer-like assemblies, exhibit a well-dispersed property even in Dulbecco's phosphate-buffered saline and do not aggregate for a period of at least 20days. The structure, morphology and assembly mechanism are systematically studied by (29)Si MAS NMR, FT-IR, (1)H NMR, SEM, FE-TEM, DLS and AFM, and the change in assemblies during the drug release is monitored using FE-TEM images. MTT assays indicate that the assemblies only have low cytotoxicity, while CLSM and TEM observations reveal that the assemblies can easily penetrate cultured human endothelial cells. When clopidogrel is used as a guest molecule, the assemblies show not only much higher loading capacities compared to MTM and other containing β-CD assemblies or nanoparticles, but also a sustained release of clopidogrel up to 30days. This is attributed to the fact that the guest molecule is both supramolecularly complexed within the dendritic scaffold and intercalated into CD and MTM hosts. Host-guest systems between assemblies and various guests hold promising applications in drug delivery system and in the biomedical fields. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Modeling Sustained Delivery of Agroecosystem Services at a Watershed Scale under Climate Change

    Science.gov (United States)

    Jaradat, A. A.; Starr, J.

    2015-12-01

    The intensive land use and agricultural production systems in the Chippewa River Watershed (CRW) in Minnesota, USA, contribute to inherent environmental problems and have major direct impact on soil conservation, and on several competing agro-ecosystem services (AESs); and may have indirect impact on AESs in the Upper Mississippi River Basin (UMRB). Field-scale indicators of AESs are largely absent in the highly diverse soils of the CRW. Therefore, proxy indicators were developed to assess these services under current (A0) and predicted (A2; 100 years) global climate change (GCC) scenarios. Individual indices were developed for biomass, grain yield, NO3- and NH4-N, soil carbon, runoff, and soil erosion for 132 soil series classified into three land capability classes (LCCs). The indices and a weighted index (Iw) were subjected to multivariate analyses procedures, including distance-weighted least squares, and variance components estimation. Three-D maps delineated contiguous areas of increasing or decreasing AESs in response to projected GCC. Largest significant variance portions in Iw were attributed to GCC scenarios; followed by the interaction of crop rotations and LCCs within conventional and organic cropping systems. The AES were predicted with larger certainty under A2 in organically-managed LCC-1 compared to conventional management. Significantly more runoff and soil erosion are predicted in conventionally-managed LCC-2 and LCC-3 under the same GCC scenario, regardless of soil heterogeneity. The modeling framework and the mapped AES indicators are designed to achieve multiple goals and will be used to support farmers in designing specific crop rotations that are suitable for each of the three LCCs and for major and vulnerable soil series in the watershed. Also, the modeling framework will address sustained delivery of multiple AESs, while enhancing soil conservation, water quality, and environmental protection aspects of farming in the CRW and the UMRB.

  7. Sustained prevention of biofilm formation on a novel silicone matrix suitable for medical devices.

    Science.gov (United States)

    Steffensen, Søren Langer; Vestergaard, Merete Hedemark; Groenning, Minna; Alm, Martin; Franzyk, Henrik; Nielsen, Hanne Mørck

    2015-08-01

    Bacterial colonization and biofilm formation on medical devices constitute major challenges in clinical long-term use of e.g. catheters due to the risk of (re)infection of patients, which would result in additional use of antibiotics risking bacterial resistance development. The aim of the present project was to introduce a novel antibacterial approach involving an advanced composite material applicable for medical devices. The polymeric composites investigated consisted of a hydrogel network of cross-linked poly(2-hydroxyethyl methacrylate) (PHEMA) embedded in a poly(dimethylsiloxane) (PDMS) silicone elastomer produced using supercritical carbon dioxide (scCO2). In these materials, the hydrogel may contain an active pharmaceutical ingredient while the silicone elastomer provides the sufficient mechanical stability of the material. In these conceptual studies, the antimicrobial agent ciprofloxacin was loaded into the polymer matrix by a post-polymerization loading procedure. Sustained release of ciprofloxacin was demonstrated, and the release could be controlled by varying the hydrogel content in the range 13-38% (w/w) and by changing the concentration of ciprofloxacin during loading in the range of 1-20mg/mL. Devices containing 25% (w/w) hydrogel and loaded with ciprofloxacin displayed a strong antibacterial effect against Staphylococcus aureus bacterial colonization and subsequent biofilm formation on the device material was inhibited for 29days. In conclusion, the hydrogel/silicone composite represents a promising candidate material for medical devices that prevent bacterial colonization during long-term use. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Controlled power delivery for super-resolution imaging of biological samples using digital micromirror device

    Science.gov (United States)

    Valiya Peedikakkal, Liyana; Cadby, Ashley

    2017-02-01

    Localization based super resolution images of a biological sample is generally achieved by using high power laser illumination with long exposure time which unfortunately increases photo-toxicity of a sample, making super resolution microscopy, in general, incompatible with live cell imaging. Furthermore, the limitation of photobleaching reduces the ability to acquire time lapse images of live biological cells using fluorescence microscopy. Digital Light Processing (DLP) technology can deliver light at grey scale levels by flickering digital micromirrors at around 290 Hz enabling highly controlled power delivery to samples. In this work, Digital Micromirror Device (DMD) is implemented in an inverse Schiefspiegler telescope setup to control the power and pattern of illumination for super resolution microscopy. We can achieve spatial and temporal patterning of illumination by controlling the DMD pixel by pixel. The DMD allows us to control the power and spatial extent of the laser illumination. We have used this to show that we can reduce the power delivered to the sample to allow for longer time imaging in one area while achieving sub-diffraction STORM imaging in another using higher power densities.

  9. Gene Silencing in Skin After Deposition of Self-Delivery siRNA With a Motorized Microneedle Array Device.

    Science.gov (United States)

    Hickerson, Robyn P; Wey, Winston C; Rimm, David L; Speaker, Tycho; Suh, Susie; Flores, Manuel A; Gonzalez-Gonzalez, Emilio; Leake, Devin; Contag, Christopher H; Kaspar, Roger L

    2013-10-22

    Despite the development of potent siRNAs that effectively target genes responsible for skin disorders, translation to the clinic has been hampered by inefficient delivery through the stratum corneum barrier and into the live cells of the epidermis. Although hypodermic needles can be used to transport siRNA through the stratum corneum, this approach is limited by pain caused by the injection and the small volume of tissue that can be accessed by each injection. The use of microneedle arrays is a less painful method for siRNA delivery, but restricted payload capacity limits this approach to highly potent molecules. To address these challenges, a commercially available motorized microneedle array skin delivery device was evaluated. This device combines the positive elements of both hypodermic needles and microneedle array technologies with little or no pain to the patient. Application of fluorescently tagged self-delivery (sd)-siRNA to both human and murine skin resulted in distribution throughout the treated skin. In addition, efficient silencing (78% average reduction) of reporter gene expression was achieved in a transgenic fluorescent reporter mouse skin model. These results indicate that this device effectively delivers functional sd-siRNA with an efficiency that predicts successful clinical translation.Molecular Therapy-Nucleic Acids (2013) 2, e129; doi:10.1038/mtna.2013.56; published online 22 October 2013.

  10. Gene Silencing in Skin After Deposition of Self-Delivery siRNA With a Motorized Microneedle Array Device

    Directory of Open Access Journals (Sweden)

    Robyn P Hickerson

    2013-01-01

    Full Text Available Despite the development of potent siRNAs that effectively target genes responsible for skin disorders, translation to the clinic has been hampered by inefficient delivery through the stratum corneum barrier and into the live cells of the epidermis. Although hypodermic needles can be used to transport siRNA through the stratum corneum, this approach is limited by pain caused by the injection and the small volume of tissue that can be accessed by each injection. The use of microneedle arrays is a less painful method for siRNA delivery, but restricted payload capacity limits this approach to highly potent molecules. To address these challenges, a commercially available motorized microneedle array skin delivery device was evaluated. This device combines the positive elements of both hypodermic needles and microneedle array technologies with little or no pain to the patient. Application of fluorescently tagged self-delivery (sd-siRNA to both human and murine skin resulted in distribution throughout the treated skin. In addition, efficient silencing (78% average reduction of reporter gene expression was achieved in a transgenic fluorescent reporter mouse skin model. These results indicate that this device effectively delivers functional sd-siRNA with an efficiency that predicts successful clinical translation.

  11. Self-reinforcement and protein sustained delivery of hyaluronan hydrogel by tailoring a dually cross-linked network

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Chunhong; Xu, Guoguang; Wang, Xinghui [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Tu, Mei; Zeng, Rong; Rong, Jianhua [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Zhao, Jianhao, E-mail: jhzhao@jnu.edu.cn [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China)

    2015-01-01

    A series of self-reinforcing hyaluronan hydrogels were developed to improve mechanical properties and protein sustained delivery thanks to a dually cross-linked network. Hyaluronan gel particles (HGPs, 1–5 μm in diameter) with different cross-linking densities, i.e. HGPs-1.5, HGPs-3 and HGPs-15, were prepared in an inverse emulsion system and used as the reinforcing phase after glycidyl methacrylation, while glycidyl methacrylated hyaluronan with a substitution degree of 45.2% was synthesized as the matrix phase. These two phases were cross-linked under ultraviolet irradiation to form self-reinforcing hyaluronan hydrogels (srHAs) that showed typical cross-linked structure of HGPs connecting the matrix phase by cross-section observation. In comparison to hyaluronan bulk gels and their blends with HGPs, srHAs distinctly enhanced the mechanical properties and BSA long-term sustained delivery, especially srHA-1.5 showed the highest compressive modulus of 220 ± 15 kPa and the slowest BSA delivery (67% release at 14 d). The 3T3 fibroblast cell culture showed that all the srHAs had no cytotoxicity. - Highlights: • New self-reinforcing HA hydrogels with a dually cross-linked network were developed. • Self-reinforcing HA hydrogels greatly enhanced the mechanical properties. • Self-reinforcing HA hydrogels prolonged the sustained delivery of BSA. • The self-reinforcing mechanism and BSA diffusion mechanism were discussed. • Self-reinforcing HA hydrogels had no cytotoxicity to 3T3 fibroblast cells.

  12. Formulation Study and Evaluation of Matrix and Three-layer Tablet Sustained Drug Delivery Systems Based on Carbopols with Isosorbite Mononitrate

    National Research Council Canada - National Science Library

    Efentakis, M; Peponaki, C

    2008-01-01

    The purpose of this research was to develop and evaluate different preparations of sustained delivery systems, using Carbopols as carriers, in the form of matrices and three-layer tablets with isosorbite mononitrate...

  13. Design and Near-Infrared Actuation of a Gold Nanorod–Polymer Microelectromechanical Device for On-Demand Drug Delivery

    Directory of Open Access Journals (Sweden)

    John Jackson

    2018-01-01

    Full Text Available Polymeric drug delivery systems usually deliver drugs by diffusion with an initial burst of release followed by a slower prolonged release phase. An optimal system would release exact doses of drugs using an on-demand external actuation system. The purpose of this study was to design and characterize a novel drug-delivery device that utilizes near infrared (NIR 800 nm laser-actuated drug release. The device was constructed from biocompatible polymers comprising a reservoir of drug covered by an elastic perforated diaphragm composed of a bilayer of two polymers with different thermal expansion coefficients (ethylenevinylacetate (EVA and polydimethylsiloxane (PDMS containing gold nanoparticles. Upon illumination with a NIR laser, the gold nanoparticles rapidly heated the bilayer resulting in bending and a drug-pumping action through the perforated bilayer, following sequential laser-actuation cycles. Devices filled with the anti-proliferative drug docetaxel were seen to release only small amounts of drug by diffusion but to release large and reproducible amounts of drug over 20 s laser-actuation periods. Because NIR 800 nm is tissue-penetrating without heating tissue, suitable geometry drug-delivery devices might be implanted in the body to be actuated by an externally applied NIR laser to allow for on-demand exact drug dosing in vivo.

  14. A pharmacokinetic study of GC-1 delivery using a nanochannel membrane device.

    Science.gov (United States)

    Filgueira, Carly S; Ballerini, Andrea; Nicolov, Eugenia; Chua, Corrine Ying Xuan; Jain, Priya; Smith, Zachary W; Gilbert, April L; Scaglione, Francesco; Grattoni, Alessandro

    2017-07-01

    This study demonstrated a nanochannel membrane device (NMD) for controlled and sustained release of GC-1 in rats, in the context of the treatment of metabolic syndrome. Release profiles were established in vitro both with and without 5% labrasol for over 2 months. In vivo pharmacokinetic evaluation showed effective GC-1 plasma concentrations, which resulted in significant reductions in body weight after just one week of treatment when compared to the NMD releasing vehicle only (PBS). We also provided evidence that rats treated with NMD-GC-1 present sub-active thyroids and clear differences in the morphology of the epithelium and follicles as compared to the controls, while the heart showed changes in weight. Moreover, body temperatures remained stable throughout treatment, and glucose, pancreatic islet size, and liver histology appeared similar between the treated and control groups. Prolonged constant administration of GC-1 from the NMD proved to be a valid strategy to facilitate weight loss. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Sustained delivery of biomolecules from gelatin carriers for applications in bone regeneration

    NARCIS (Netherlands)

    Song, J.; Leeuwenburgh, S.C.G.

    2014-01-01

    Local delivery of therapeutic biomolecules to stimulate bone regeneration has matured considerably during the past decades, but control over the release of these biomolecules still remains a major challenge. To this end, suitable carriers that allow for tunable spatial and temporal delivery of

  16. Advances in thermal-hydraulic studies of a transmutation advanced device for sustainable energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Fajardo, Laura Garcia, E-mail: laura.gf@cern.ch [European Organization for Nuclear Research (CERN), Geneva (Switzerland). Technology Department; Hernandez, Carlos Garcia; Mazaira, Leorlen Rojas, E-mail: cgh@instec.cu, E-mail: irojas@instec.cu [Higher Institute of Technologies and Applied Sciences (INSTEC), Habana (Cuba); Castells, Facundo Alberto Escriva, E-mail: aescriva@iqn.upv.es [University of Valencia (UV), Valencia (Spain). Energetic Engineering Institute; Lira, Carlos Brayner de Olivera, E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (BRazil). Dept. de Engenharia Nuclear

    2013-07-01

    The Transmutation Advanced Device for Sustainable Energy Applications (TADSEA) is a pebble-bed Accelerator Driven System (ADS) with a graphite-gas configuration, designed for nuclear waste trans- mutation and for obtaining heat at very high temperatures to produce hydrogen. In previous work, the TADSEA's nuclear core was considered as a porous medium performed with a CFD code and thermal-hydraulic studies of the nuclear core were presented. In this paper, the heat transfer from the fuel to the coolant was analyzed for three core states during normal operation. The heat transfer inside the spherical fuel elements was also studied. Three critical fuel elements groups were defined regarding their position inside the core. Results were compared with a realistic CFD model of the critical fuel elements groups. During the steady state, no critical elements reached the limit temperature of this type of fuel. (author)

  17. Delivery of nicotine aerosol to mice via a modified electronic cigarette device.

    Science.gov (United States)

    Lefever, Timothy W; Lee, Youn O K; Kovach, Alexander L; Silinski, Melanie A R; Marusich, Julie A; Thomas, Brian F; Wiley, Jenny L

    2017-03-01

    Although both men and women use e-cigarettes, most preclinical nicotine research has focused on its effects in male rodents following injection. The goals of the present study were to develop an effective e-cigarette nicotine delivery system, to compare results to those obtained after subcutaneous (s.c.) injection, and to examine sex differences in the model. Hypothermia and locomotor suppression were assessed following aerosol exposure or s.c. injection with nicotine in female and male mice. Subsequently, plasma and brain concentrations of nicotine and cotinine were measured. Passive exposure to nicotine aerosol produced concentration-dependent and mecamylamine reversible hypothermic and locomotor suppressant effects in female and male mice, as did s.c. nicotine injection. In plasma and brain, nicotine and cotinine concentrations showed dose/concentration-dependent increases in both sexes following each route of administration. Sex differences in nicotine-induced hypothermia were dependent upon route of administration, with females showing greater hypothermia following aerosol exposure and males showing greater hypothermia following injection. In contrast, when they occurred, sex differences in nicotine and cotinine levels in brain and plasma consistently showed greater concentrations in females than males, regardless of route of administration. In summary, the e-cigarette exposure device described herein was used successfully to deliver pharmacologically active doses of nicotine to female and male mice. Further, plasma nicotine concentrations following exposure were similar to those after s.c. injection with nicotine and within the range observed in human smokers. Future research on vaped products can be strengthened by inclusion of translationally relevant routes of administration. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Fabrication of porous polymeric matrix drug delivery devices using the selective laser sintering technique.

    Science.gov (United States)

    Leong, K F; Phua, K K; Chua, C K; Du, Z H; Teo, K O

    2001-01-01

    New techniques in solid freeform fabrication (SFF) have prompted research into methods of manufacturing and controlling porosity. The strategy of this research is to integrate computer aided design (CAD) and the SFF technique of selective laser sintering (SLS) to fabricate porous polymeric matrix drug delivery devices (DDDs). This study focuses on the control of the porosity of a matrix by manipulating the SLS process parameters of laser beam power and scan speed. Methylene blue dye is used as a drug model to infiltrate the matrices via a degassing method; visual inspection of dye penetration into the matrices is carried out. Most notably, the laser power matrices show a two-stage penetration process. The matrices are sectioned along the XZ planes and viewed under scanning electron microscope (SEM). The morphologies of the samples reveal a general increase in channel widths as laser power decreases and scan speed increases. The fractional release profiles of the matrices are determined by allowing the dye to diffuse out in vitro within a controlled environment. The results show that laser power and scan speed matrices deliver the dye for 8-9 days and have an evenly distributed profile. Mercury porosimetry is used to analyse the porosity of the matrices. Laser power matrices show a linear relationship between porosity and variation in parameter values. However, the same relationship for scan speed matrices turns out to be rather inconsistent. Relationships between the SLS parameters and the experimental results are developed using the fractional release rate equation for the infinite slab porous matrix DDD as a basis for correlation.

  19. Assessment of new-generation high-power electronic nicotine delivery system as thermal aerosol generation device for inhaled bronchodilators.

    Science.gov (United States)

    Pourchez, Jérémie; de Oliveira, Fabien; Perinel-Ragey, Sophie; Basset, Thierry; Vergnon, Jean-Michel; Prévôt, Nathalie

    2017-02-25

    A need remains for alternative devices for aerosol drug delivery that are low cost, convenient and easy to use for the patient, but also capable of producing small-sized aerosol particles. This study investigated the potential of recent high power electronic nicotine delivery systems (ENDS) as aerosol generation devices for inhaled bronchodilators. The particle size distribution was measured using a cascade impactor. The delivery of terbutaline sulfate, a current bronchodilator used for asthma or COPD therapy by inhalation, was studied. This drug was quantified by liquid chromatography coupled with tandem mass spectrometry. The particle size distribution in terms of mass frequency (in two ways, gravimetrically and quantitatively through drug assay on each stage) and the terbutaline sulfate concentration in the aerosol were elucidated. The mass median aerodynamic diameter (MMAD) and the drug delivery rose when the power level increased, to reach 5.6±0.4μg/puff with a MMAD of 0.78±0.03μm at 25W. New generation high-power ENDS are very efficient to generate carrier-droplets in the submicron range containing drug molecules with a constant drug concentration whatever the size-fractions. ENDS appear to be highly patient-adaptive. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Evaluation of superabsorbent linseed-polysaccharides as a novel stimuli-responsive oral sustained release drug delivery system.

    Science.gov (United States)

    Haseeb, Muhammad Tahir; Hussain, Muhammad Ajaz; Bashir, Sajid; Ashraf, Muhammad Umer; Ahmad, Naveed

    2017-03-01

    Advancement in technology has transformed the conventional dosage forms to intelligent drug delivery systems. Such systems are helpful for targeted and efficient drug delivery with minimum side effects. Drug release from these systems is governed and controlled by external stimuli (pH, enzymes, ions, glucose, etc.). Polymeric biomaterial having stimuli-responsive properties has opened a new area in drug delivery approach. Potential of a polysaccharide (rhamnogalacturonan)-based hydrogel from Linseeds (Linum usitatissimum L.) was investigated as an intelligent drug delivery material. Different concentrations of Linseed hydrogel (LSH) were used to prepare caffeine and diacerein tablets and further investigated for pH and salt solution-responsive swelling, pH-dependent drug release, and release kinetics. Morphology of tablets was observed using SEM. LSH tablets exhibited dynamic swelling-deswelling behavior with tendency to swell at pH 7.4 and in deionized water while deswell at pH 1.2, in normal saline and ethanol. Consequently, pH controlled release of the drugs was observed from tablets with lower release (drug release was greatly influenced by the amount of LSH in the tablets. Drug release from LSH tablets was governed by the non-Fickian diffusion. These finding indicates that LSH holds potential to be developed as sustained release material for tablet.

  1. Modifications to ART service delivery models by health facilities in Uganda in promotion of intervention sustainability: a mixed methods study.

    Science.gov (United States)

    Zakumumpa, Henry; Bennett, Sara; Ssengooba, Freddie

    2017-04-04

    In November 2015, WHO released new treatment guidelines recommending that all diagnosed as HIV positive be enrolled on antiretroviral therapy (ART). Sustaining and expanding ART scale-up programs in resource-limited settings will require adaptations and modifications to traditional ART delivery models to meet the rapid increase in demand. We identify modifications to ART service delivery models by health facilities in Uganda to sustain ART interventions over a 10-year period (2004-2014). A mixed methods approach involving two study phases was adopted. In the first phase, a survey of a nationally representative sample of health facilities (n = 195) in Uganda which were accredited to provide ART between 2004 and 2009 was conducted. The second phase involved semi-structured interviews (n = 18) with ART clinic managers of 6 of the 195 health facilities purposively selected from the first study phase. We adopted a thematic framework consisting of four categories of modifications (format, setting, personnel, and population). The majority of health facilities 185 (95%) reported making modifications to ART interventions between 2004 and 2014. Of the 195 health facilities, 157 (81%) rated the modifications made to ART as "major." Modifications to ART were reported under all the four themes. The quantitative and qualitative findings are integrated and presented under four themes. Format: Reducing the frequency of clinic appointments and pharmacy-only refill programs was identified as important strategies for decongesting ART clinics. Home-based care programs were introduced to reduce provider ART delivery costs. Personnel: Task shifting to non-physician cadre was reported in 181 (93%) of the health facilities. Visits to the ART clinic were rationalized in favor of the sub-population deemed to have more clinical need. Two health facilities focused on patients living nearer the health facilities to align with targets set by external donors. Over the study period

  2. Fabrication of multi-layered biodegradable drug delivery device based on micro-structuring of PLGA polymers.

    Science.gov (United States)

    Ryu, Won Hyoung; Vyakarnam, Murty; Greco, Ralph S; Prinz, Fritz B; Fasching, Rainer J

    2007-12-01

    A programmable and biodegradable drug delivery device is desirable when a drug needs to be administered locally. While most local drug delivery devices made of biodegradable polymers relied on the degradation of the polymers, the degradation-based release control is often limited by the property of the polymers. Thus, we propose micro-geometry as an alternative measure of controlling drug release. The proposed devices consist of three functional layers: diffusion control layer via micro-orifices, diffusion layer, and drug reservoir layers. A micro-fabrication technology was used to shape an array of micro-orifices and micro-cavities in 85/15PLGA layers. A thin layer of fast degrading 50/50PLGA was placed as the diffusion layer between the 85/15PLGA layers to prevent any burst-type release. To modulate the release of the devices, the dimension and location of the micro-orifices were varied and the responding in vitro release response of tetracycline was monitored over 2 weeks. The release response to the different micro-geometry was prominent and further analyzed by FEM simulation. Comparison of the experiments to the simulated results identified that the variation of micro-geometry influenced also the volume-dependent degradation rate and induced the osmotic pressure.

  3. Formulation and evaluation of sustained release enteric-coated pellets of budesonide for intestinal delivery

    National Research Council Canada - National Science Library

    Raval, Mihir K; Ramani, Riddhi V; Sheth, Navin R

    2013-01-01

    ...) full factorial design by giving an enteric coating with Eudragit S100. Budesonide-sustained release pellets were prepared by extruder and spheronization technique using a combination of water-soluble and permeable polymers by applying 3(2...

  4. Solid cellulose nanofiber based foams - Towards facile design of sustained drug delivery systems

    DEFF Research Database (Denmark)

    Svagan, Anna J; Benjamins, Jan-Willem; Al-Ansari, Zeinab

    2016-01-01

    Control of drug action through formulation is a vital and very challenging topic within pharmaceutical sciences. Cellulose nanofibers (CNF) are an excipient candidate in pharmaceutical formulations that could be used to easily optimize drug delivery rates. CNF has interesting physico-chemical pro......Control of drug action through formulation is a vital and very challenging topic within pharmaceutical sciences. Cellulose nanofibers (CNF) are an excipient candidate in pharmaceutical formulations that could be used to easily optimize drug delivery rates. CNF has interesting physico...

  5. Effect of an electronic nicotine delivery device (e-Cigarette on smoking reduction and cessation: a prospective 6-month pilot study

    Directory of Open Access Journals (Sweden)

    Papale Gabriella

    2011-10-01

    Full Text Available Abstract Background Cigarette smoking is a tough addiction to break. Therefore, improved approaches to smoking cessation are necessary. The electronic-cigarette (e-Cigarette, a battery-powered electronic nicotine delivery device (ENDD resembling a cigarette, may help smokers to remain abstinent during their quit attempt or to reduce cigarette consumption. Efficacy and safety of these devices in long-term smoking cessation and/or smoking reduction studies have never been investigated. Methods In this prospective proof-of-concept study we monitored possible modifications in smoking habits of 40 regular smokers (unwilling to quit experimenting the 'Categoria' e-Cigarette with a focus on smoking reduction and smoking abstinence. Study participants were invited to attend a total of five study visits: at baseline, week-4, week-8, week-12 and week-24. Product use, number of cigarettes smoked, and exhaled carbon monoxide (eCO levels were measured at each visit. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed. Results Sustained 50% reduction in the number of cig/day at week-24 was shown in 13/40(32.5% participants; their median of 25 cigs/day decreasing to 6 cigs/day (p Conclusion The use of e-Cigarette substantially decreased cigarette consumption without causing significant side effects in smokers not intending to quit (http://ClinicalTrials.gov number NCT01195597.

  6. Sustained improvement in clinical preventive service delivery among independent primary care practices after implementing electronic health record systems.

    Science.gov (United States)

    Wang, Jason J; Sebek, Kimberly M; McCullough, Colleen M; Amirfar, Sam J; Parsons, Amanda S; Singer, Jesse; Shih, Sarah C

    2013-08-01

    Studies showing sustained improvements in the delivery of clinical preventive services are limited. Fewer studies demonstrate sustained improvements among independent practices that are not affiliated with hospitals or integrated health systems. This study examines the continued improvement in clinical quality measures for a group of independent primary care practices using electronic health records (EHRs) and receiving technical support from a local public health agency. We analyzed clinical quality measure performance data from a cohort of primary care practices that implemented an EHR at least 3 months before October 2009, the study baseline. We assessed trends for 4 key quality measures: antithrombotic therapy, blood pressure control, smoking cessation intervention, and hemoglobin A1c (HbA1c) testing based on monthly summary data transmitted by the practices. Of the 151 practices, 140 were small practices and 11 were community health centers; average time using an EHR was 13.7 months at baseline. From October 2009 through October 2011, average rates increased for antithrombotic therapy (from 58.4% to 74.8%), blood pressure control (from 55.3% to 64.1%), HbA1c testing (from 46.4% to 57.7%), and smoking cessation intervention (from 29.3% to 46.2%). All improvements were significant. During 2 years, practices showed significant improvement in the delivery of several key clinical preventive services after implementing EHRs and receiving support services from a public health agency.

  7. Bioactive Glass Nanoparticles as a New Delivery System for Sustained 5-Fluorouracil Release: Characterization and Evaluation of Drug Release Mechanism

    Directory of Open Access Journals (Sweden)

    Abeer M. El-Kady

    2015-01-01

    Full Text Available Bioactive glass nanoparticles were synthesized and tested for the first time as a new delivery system for sustained 5-fluorouracil (5-FU release. They were characterized by TEM, DTA, TGA, and FT-IR. The porosity % and specific surface area of glass nanoparticles were 85.59% and 378.36 m2/g, respectively. The in vitro bioactivity evaluation confirmed that bioactive glass disks prepared from these nanoparticles could induce hydroxyapatite layer over their surfaces in simulated body fluid. The in vitro drug release experiment indicated that glass nanoparticles could serve as long-term local delivery vehicles for sustained 5-FU release. The release profile of 5-FU showed an initial fast release stage followed by a second stage of slower release. The initial burst release of 5-FU in the first day was about 23% (28.92 mg·L−1 of the total amount of loaded 5-FU, while the final cumulative percentage of the 5-FU released after 32 days was about 45.6% (57.31 mg·L−1 of the total amount of loaded 5-FU. The application of different mathematical models indicated that 5-FU was released by diffusion controlled mechanism and suggested that its release rate was dependent on glass particles dissolution, changes of surface area as well as diameter of glass particles, and concentration of loaded drug.

  8. Designing Novel Smart Hydrogel Formulations for the Controlled Delivery of Ocular Therapies in Contact Lens Devices

    OpenAIRE

    Phelan, David

    2015-01-01

    The major challenge to ocular drug delivery is poor bio-availability of the delivered drug, due to the anatomy of the eye. This work presents an approach to address this problem, using novel contact lens drug delivery vehicles. Antihistamines were used as a model drug due to their physical properties and molecular weight. 15% of the world’s population suffer from allergic reactions confirming antihistamines as a relevant ocular pharmaceutical. A novel pilot scale wet cast moulding proce...

  9. Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound

    Science.gov (United States)

    Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K. Kirk

    2016-02-01

    Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca2+ and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity.

  10. Surface Engineering of Porous Silicon Microparticles for Intravitreal Sustained Delivery of Rapamycin

    OpenAIRE

    Nieto, Alejandra; Hou, Huiyuan; Moon, Sang Woong; Sailor, Michael J.; Freeman, William R.; Cheng, Lingyun

    2015-01-01

    Mild oxidation and subsequent silanization of the porous silicon (pSi) rendered the resultant pSi particles optimized for rapamycin loading/release as an intravitreal injectable delivery system. The system slowly released rapamycin and safely resided in rabbit vitreous more than 8 weeks.

  11. Structural and biological properties of thermosensitive chitosan-graphene hybrid hydrogels for sustained drug delivery applications.

    Science.gov (United States)

    Saeednia, Leyla; Yao, Li; Berndt, Marcus; Cluff, Kim; Asmatulu, Ramazan

    2017-09-01

    Chitosan has the ability to make injectable thermosensitive hydrogels which has been highly investigated for drug delivery applications. The addition of nanoparticles is one way to increase the mechanical strength of thermosensitive chitosan hydrogel and subsequently and control the burst release of drug. Graphene nanoparticles have shown unique mechanical, optical and electrical properties which can be exploited for biomedical applications, especially in drug delivery. This study, have focused on the mechanical properties of a thermosensitive and injectable hybrid chitosan hydrogel incorporated with graphene nanoparticles. Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD) have been used for morphological and chemical characterization of graphene infused chitosan hydrogels. The cell viability and cytotoxicity of graphene-contained hydrogels were analyzed using the alamarBlue® technique. In-vitro methotrexate (MTX) release was investigated from MTX-loaded hybrid hydrogels as well. As a last step, to evaluate their efficiency as a cancer treatment delivery system, an in vitro anti-tumor test was also carried out using MCF-7 breast cancer cell lines. Results confirmed that a thermosensitive chitosan-graphene hybrid hydrogel can be used as a potential breast cancer therapy system for controlled delivery of methotrexate. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2381-2390, 2017. © 2017 Wiley Periodicals, Inc.

  12. Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound.

    Science.gov (United States)

    Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K Kirk

    2016-02-04

    Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca(2+) and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity.

  13. Remote-controlled delivery of CO via photoactive CO-releasing materials on a fiber optical device.

    Science.gov (United States)

    Gläser, Steve; Mede, Ralf; Görls, Helmar; Seupel, Susanne; Bohlender, Carmen; Wyrwa, Ralf; Schirmer, Sina; Dochow, Sebastian; Reddy, Gandra Upendar; Popp, Jürgen; Westerhausen, Matthias; Schiller, Alexander

    2016-08-16

    Although carbon monoxide (CO) delivery materials (CORMAs) have been generated, remote-controlled delivery with light-activated CORMAs at a local site has not been achieved. In this work, a fiber optic-based CO delivery system is described in which the photoactive and water insoluble CO releasing molecule (CORM) manganese(i) tricarbonyl [(OC)3Mn(μ3-SR)]4 (R = nPr, 1) has been non-covalently embedded into poly(l-lactide-co-d/l-lactide) and poly(methyl methacrylate) non-woven fabrics via the electrospinning technique. SEM images of the hybrid materials show a porous fiber morphology for both polymer supports. The polylactide non-woven fabric was attached to a fiber optical device. In combination with a laser irradiation source, remote-controlled and light-triggered CO release at 405 nm excitation wavelength was achieved. The device enabled a high flexibility of the spatially and timely defined application of CO with the biocompatible hybrid fabric in aqueous media. The rates of liberated CO were adjusted with the light intensity of the laser. CO release was confirmed via ATR-IR spectroscopy, a portable electrochemical CO sensor and a heterogeneous myoglobin assay.

  14. Modified thermoresponsive Poloxamer 407 and chitosan sol-gels as potential sustained-release vaccine delivery systems.

    Science.gov (United States)

    Kojarunchitt, Thunjiradasiree; Baldursdottir, Stefania; Dong, Yao-Da; Boyd, Ben J; Rades, Thomas; Hook, Sarah

    2015-01-01

    Thermoresponsive, particle-loaded, Poloxamer 407 (P407)-Pluronic-R® (25R4) or chitosan-methyl cellulose (MC) formulations were developed as single-dose, sustained release vaccines. The sol-gels, loaded either with a particulate vaccine (cubosomes) or soluble antigen (ovalbumin) and adjuvants (Quil A and monophosphoryl lipid A), were free-flowing liquids at room temperature and formed stable gels at physiological temperatures. Rheological results showed that both systems meet the criteria of being thermoresponsive gels. The P407-25R4 sol-gels did not significantly sustain the release of antigen in vivo while the chitosan-MC sol-gels sustained the release of antigen up to at least 14 days after administration. The chitosan-MC sol-gels stimulated both cellular and humoral responses. The inclusion of cubosomes in the sol-gels did not provide a definitive beneficial effect. Further analysis of the formulations with small-angle X-ray scattering (SAXS) revealed that while cubosomes were stable in chitosan-MC gels they were not stable in P407-25R4 formulations. The reason for the mixed response to cubosome-loaded vehicles requires more investigation, however it appears that the cubosomes did not facilitate synchronous vaccine release and may in fact retard release, reducing efficacy in some cases. From these results, chitosan-MC sol-gels show potential as sustained release vaccine delivery systems, as compared to the P407-25R4 system that had a limited ability to sustain antigen release. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Sustained delivery of rhBMP-2 via PLGA microspheres: cranial bone regeneration without heterotopic ossification or craniosynostosis

    Science.gov (United States)

    Wink, Jason D.; Gerety, Patrick A.; Sherif, Rami D.; Lim, Youngshin; A.Clarke, Nadya; Rajapakse, Chamith S.; Nah, Hyun-Duck; Taylor, Jesse A.

    2014-01-01

    Background Commercially available recombinant human bone morphogenetic protein 2 (rhBMP2) has demonstrated efficacy in bone regeneration, but not without significant side effects. In this study, we utilize rhBMP2 encapsulated in PLGA microspheres (PLGA-rhBMP2) placed in a rabbit cranial defect model to test whether low-dose, sustained, delivery can effectively induce bone regeneration. Methods rhBMP2 was encapsulated in 15% poly (lactic-co-glycolic acid), using a double emulsion, solvent extraction/evaporation technique, and its release kinetics and bioactivity were tested. Two critical-size defects (10mm) were created in the calvarium of New Zealand White rabbits (5-7 mos of age, M/F) and filled with a collagen scaffold containing one of four groups: 1) no implant, 2) collagen scaffold only, 3) PLGA-rhBMP2(0.1ug/implant), or 4) free rhBMP2 (0.1ug/implant). After 6 weeks, the rabbits were sacrificed and defects were analyzed by μCT, histology, and finite element analysis. Results RhBMP2 delivered via bioactive PLGA microspheres resulted in higher volumes and surface area coverage of new bone than an equal dose of free rhBMP2 by μCT and histology (p=0.025, 0.025). FEA indicated that the mechanical competence using the regional elastic modulus did not differ with rhBMP2 exposure (p=0.70). PLGA-rhBMP2 did not demonstrate heterotopic ossification, craniosynostosis, or seroma formation. Conclusions Sustained delivery via PLGA microspheres can significantly reduce the rhBMP2 dose required for de novo bone formation. Optimization of the delivery system may be a key to reduce the risk for recently reported rhBMP2 related adverse effects. Level of Evidence Animal Study PMID:24622573

  16. Comparison of drug delivery with autoinjector versus manual prefilled syringe and between three different autoinjector devices administered in pig thigh.

    Science.gov (United States)

    Hill, Robert L; Wilmot, John G; Belluscio, Beth A; Cleary, Kevin; Lindisch, David; Tucker, Robin; Wilson, Emmanuel; Shukla, Rajesh B

    2016-01-01

    Parenteral routes of drug administration are often selected to optimize actual dose of drug delivered, assure high bioavailability, bypass first-pass metabolism or harsh gastrointestinal environments, as well as maximize the speed of onset. Intramuscular (IM) delivery can be preferred to intravenous delivery when initiating intravenous access is difficult or impossible. Drugs can be injected intramuscularly using a syringe or an automated delivery device (autoinjector). Investigation into the IM delivery dynamics of these methods may guide further improvements in the performance of injection technologies. Two porcine model studies were conducted to compare differences in dispersion of injectate volume for different methods of IM drug administration. The first study compared the differences in the degree of dispersion and uptake of injectate following the use of a manual syringe and an autoinjector. The second study compared the spatial spread of the injected formulation, or dispersion volume, and uptake of injectate following the use of five different autoinjectors (EpiPen(®) [0.3 mL], EpiPen(®) Jr [0.3 mL], Twinject(®) [0.15 mL, 0.3 mL], and Anapen(®) 300 [0.3 mL]) with varying needle length, needle gauge, and force applied to the plunger. In the first study, the autoinjector provided higher peak volumes of injectate, indicating a greater degree of dispersion, compared with manual syringe delivery. In the second study, EpiPen autoinjectors resulted in larger dispersion volumes and higher initial dispersion ratios, which decreased rapidly over time, suggesting a greater rate of uptake of injectate than the other autoinjectors. The differences in dispersion and uptake of injectate are likely the result of different functional characteristics of the delivery systems. Both studies demonstrate that the functional characteristics of the method for delivering IM injections impact the dispersion and uptake of the material injected, which could significantly affect the

  17. New stage in the design of a Transmutation Advanced Device for Sustainable Energy Applications (TADSEA))

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Leorlen Y.; Rosales, Jesus; Castro, Landy Y.; Gamez, Abel; Gonzalez, Daniel; Garcia, Carlos, E-mail: leored1984@gmail.com, E-mail: jrosales@instec.cu, E-mail: lcastro@instec.cu, E-mail: agamezgmf@gmail.com, E-mail: danielgonro@gmail.com, E-mail: cgh@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Oliveira, Carlos Brayner de, E-mail: abol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Dominguez, Dany S.; Silva, Alexandro S., E-mail: dsdominguez@gmail.com, E-mail: alexandrossilva@gmail.com [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil). Pos-Graduacao em Modelagem Computacional

    2015-07-01

    Transmutation Advanced Device for Sustainable Energy Applications (TADSEA) is a pebble-bed Accelerator Driven System (ADS) with a graphite-gas configuration, designed for nuclear waste transmutation and obtaining heat at very high temperatures to produce hydrogen. In this new stage in the design of TADSEA, it was proposed and modelled a new burn-up strategy, simulating a multi-pass scheme of the pebbles through the core. In order to obtain the axial density power distribution more uniform, for more realistic thermal-hydraulic calculations. In the neutronic calculations it was considered the double heterogeneity of the fuel, by means of a detailed geometry modelling. In previous thermal-hydraulic studies of the TADSEA using CFD code, the pebble-bed nuclear core was considered as a porous medium. In this paper, the heat transfer from the fuel elements to the coolant was analysed using a realistic approach in ANSYS CFX 14. The maximum heat transfer inside the spherical fuel elements with a body centered cubic (BCC) cell and the entire height of core was studied. During the steady state, critical elements don't reached the limit temperature value for this type of fuel. (author)

  18. Functionalized, Biodegradable Hydrogels for Control over Sustained and Localized siRNA Delivery to Incorporated and Surrounding Cells

    Science.gov (United States)

    Nguyen, Khanh; Dang, Phuong Ngoc; Alsberg, Eben

    2012-01-01

    Currently, the most severe limitation to applying RNA interference (RNAi) technology is delivery, including localizing the molecules to a specific site of interest to target a specific cell population and sustaining the presentation of these molecules for a controlled period of time. In this study, we engineered a functionalized, biodegradable system created by covalent incorporation of cationic linear polyethyleneimine (LPEI) into photocrosslinked dextran (DEX) hydrogels through a biodegradable ester linkage. The key innovation of this system is that control over the sustained release of short interference RNA (siRNA) was achieved, as LPEI could electrostatically interact with siRNA to maintain siRNA within the hydrogels and degradation of the covalent ester linkages between the LPEI and the hydrogels led to tunable release of LPEI/siRNA complexes over time. The covalent conjugation of LPEI did not affect the swelling or degradation properties of the hydrogels, and the addition of siRNA and LPEI had minimal effect on their mechanical properties. These hydrogels exhibited low cytotoxicity against human embryonic kidney 293 cells (HEK293). The release profiles could be tailored by varying DEX (8 and 12 %w/w) and LPEI (0, 5, 10 μg/ 100 μl gel) concentrations with nearly 100% cumulative release achieved at day 9 (8 %w/w gel) and day 17 (12 %w/w gel). The released siRNA exhibited high bioactivity with cells surrounding and inside the hydrogels over an extended time period. This controllable and sustained siRNA delivery hydrogel system that permits tailored siRNA release profiles may be valuable to guide cell fate for regenerative medicine and other therapeutic applications such as cancer. PMID:22902819

  19. Implants as drug delivery devices for the treatment of eye diseases

    Directory of Open Access Journals (Sweden)

    Gisele Rodrigues da Silva

    2010-09-01

    Full Text Available The treatment of diseases affecting the posterior segment of the eye is limited by the difficulty in transporting effective doses of drugs to the vitreous, retina, and choroid. Topically applied drugs are poorly absorbed due to the low permeability of the external ocular tissues and tearing. The blood-retina barrier limits drug diffusion from the systemic blood to the posterior segment, thus high doses of drug are needed to maintain therapeutic levels. In addition, systemic side effects are common. Intraocular injections could be an alternative, but the fast flowing blood supply in this region, associated with rapid clearance rates, causes drug concentration to quickly fall below therapeutic levels. To obtain therapeutic levels over longer time periods, polymeric sustained-drug release systems implanted within the vitreous are being studied for the treatment of vitreoretinal disorders. These systems are prepared using different kinds of biodegradable or non-biodegradable polymers. This review aims to demonstrate the main characteristics of these drug delivery implants and their potential for clinical application.O tratamento de doenças do segmento posterior do olho é limitado pela dificuldade no transporte de doses efetivas de fármacos para o vítreo, retina e coróide. Os fármacos aplicados topicamente são pouco absorvidos por causa da baixa permeabilidade dos tecidos oculares externos e ao lacrimejamento. Embora a administração sistêmica seja capaz de transportar fármacos para o segmento posterior do olho, as barreiras hemato-aquosa e hematorretiniana dificultam a absorção e, normalmente, são necessárias doses elevadas, as quais estão geralmente associadas a potenciais efeitos adversos. Injeções intravitreais são capazes de transportar fármacos para o segmento posterior do olho, mas é uma técnica invasiva, pouco tolerada pelos pacientes e apresenta riscos de infecções oculares e danos aos tecidos. Visando a obtenção de

  20. Subcutaneous sumatriptan delivery devices: comparative ease of use and preference among migraineurs

    OpenAIRE

    Andre AD; Brand-Schieber E; Ramirez M; Munjal S; Kumar R

    2017-01-01

    Anthony D Andre,1 Elimor Brand-Schieber,2 Margarita Ramirez,1 Sagar Munjal,2 Rajesh Kumar2 1Interface Analysis Associates, Saraftoga, CA, 2Dr Reddy’s Laboratories Inc., Princeton, NJ, USA Background: Several sumatriptan subcutaneous autoinjector devices for acute treatment of migraine patients are available, each device differs with respect to design and features. Determining device preference and ease of use is important because patients experiencing a migraine attack are often f...

  1. Transcutaneous Noninvasive Device for the Responsive Delivery of Melatonin in Microgravity. Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our goal is develop a smart, transcutaneous device for individualized circadian (sleep) therapy by responsive release of melatonin, in microgravity. Additionally,...

  2. Large distance liquid pumping by AC electro-osmosis for the delivery of biological cells and reagents in microfluidic devices

    Science.gov (United States)

    Lee, Daniel; Xu, Guolin; Tng, Yongsheng; Htet, Kyaw Zin; Yang, Chun; Ying, Jackie Y.

    2008-03-01

    Liquid pumping, mixing and biological cells/reagents delivery in micro- or nano-liter volume is critical in lab-on-chip systems. We describe a novel AC electro-osmosis device for delivering reagents/cells over large distances without a global pressure gradient. Our device features facile transport range scalability in x- and y-axes, using continuous flow in a serpentine microchannel realized by microelectrode pairs arrayed in a unique antiparallel-asymmetric configuration. Co-planar microelectrodes on glass substrate are fabricated from gold with chromium as seed layer using micro-electromechanical system (MEMS) technology. Sealed upon the micro-electrodes is an open-ended serpentine microchannel having width 80μm and depth 45μm formed by micromolding PDMS with a silicon-based mold. AC signals at 3.5V pp and 0.5V DC offset is used to energize the microelectrodes, and polystyrene beads with diameter 5.0μm are used as tracer particles to visualize flow. Maximum velocity of 871 μm/s was recorded using AC signals at 8 kHz. The ease of scaling up transport distance range in 2-axes is unique to our device. Scalability in x-axis is achieved by varying the number of microelectrode pairs; and in y-axis by varying the number of microelectrodes iterations and the corresponding number of turns in the serpentine microchannel. Being scalable in transporting fluidic volume with high efficiency under small driving voltages makes our device suitable for miniaturization in a micro-total-analytical-system. Our device could be applied towards multiple point reagents, biological cells and particles delivery and mixing in a lab-on-chip.

  3. Genetically Modified Neural Stem Cells for a Local and Sustained Delivery of Neuroprotective Factors to the Dystrophic Mouse Retina

    Science.gov (United States)

    Jung, Gila; Sun, Jing; Petrowitz, Bettina; Riecken, Kristoffer; Kruszewski, Katharina; Jankowiak, Wanda; Kunst, Frank; Skevas, Christos; Richard, Gisbert; Fehse, Boris

    2013-01-01

    A continuous intraocular delivery of neurotrophic factors (NFs) is being explored as a strategy to rescue photoreceptor cells and visual functions in degenerative retinal disorders that are currently untreatable. To establish a cell-based intraocular delivery system for a sustained administration of NFs to the dystrophic mouse retina, we used a polycistronic lentiviral vector to genetically modify adherently cultivated murine neural stem (NS) cells. The vector concurrently encoded a gene of interest, a reporter gene, and a resistance gene and thus facilitated the selection, cloning, and in vivo tracking of the modified cells. To evaluate whether modified NS cells permit delivery of functionally relevant quantities of NFs to the dystrophic mouse retina, we expressed a secretable variant of ciliary neurotrophic factor (CNTF) in NS cells and grafted the cells into the vitreous space of Pde6brd1 and Pde6brd10 mice, two animal models of retinitis pigmentosa. In both mouse lines, grafted cells attached to the retina and lens, where they differentiated into astrocytes and some neurons. Adverse effects of the transplanted cells on the morphology of host retinas were not observed. Importantly, the CNTF-secreting NS cells significantly attenuated photoreceptor degeneration in both mutant mouse lines. The neuroprotective effect was significantly more pronounced when clonally derived NS cell lines selected for high expression levels of CNTF were grafted into Pde6brd1 mice. Intravitreal transplantations of modified NS cells may thus represent a useful method for preclinical studies aimed at evaluating the therapeutic potential of a cell-based intraocular delivery of NFs in mouse models of photoreceptor degeneration. PMID:24167317

  4. Nano-carrier based drug delivery systems for sustained antimicrobial agent release from orthopaedic cementous material.

    Science.gov (United States)

    Al Thaher, Yazan; Perni, Stefano; Prokopovich, Polina

    2017-11-01

    Total joint replacement (TJR), such as hip and knee replacement, is a popular procedure worldwide. Prosthetic joint infections (PJI) after this procedure have been widely reported, where treatment of such infections is complex with high cost and prolonged hospital stay. In cemented arthroplasties, the use of antibiotic loaded bone cement (ALBC) is a standard practice for the prophylaxis and treatment of PJI. Recently, the development of bacterial resistance by pathogenic microorganisms against most commonly used antibiotics increased the interest in alternative approaches for antimicrobial delivery systems such as nanotechnology. This review summarizes the efforts made to improve the antimicrobial properties of PMMA bone cements using nanotechnology based antibiotic and non-antibiotic delivery systems to overcome drawbacks of ALBC in the prophylaxis and treatment of PJIs after hip and knee replacement. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Sustained systemic delivery of monoclonal antibodies by genetically modified skin fibroblasts

    DEFF Research Database (Denmark)

    Noël, D; Pelegrin, M; Brockly, F

    2000-01-01

    In vivo production and systemic delivery of therapeutic antibodies by engineered cells might advantageously replace injection of purified antibodies for treating a variety of life-threatening diseases, including cancer, acquired immunodeficiency syndrome, and autoimmune diseases. We report here t....... This supports the notion that skin fibroblasts can potentially be used in antibody-based gene/cell therapy protocols without inducing any adverse immune response in treated individuals....

  6. Comparison of drug delivery with autoinjector versus manual prefilled syringe and between three different autoinjector devices administered in pig thigh

    Directory of Open Access Journals (Sweden)

    Hill RL

    2016-08-01

    Full Text Available Robert L Hill,1,* John G Wilmot,1,* Beth A Belluscio,1 Kevin Cleary,2 David Lindisch,3 Robin Tucker,4 Emmanuel Wilson,2 Rajesh B Shukla11Meridian Medical Technologies Inc., Columbia, MD, 2Children’s National Medical Center, 3Washington DC VA Medical Center, 4Georgetown University Medical Center, Washington, DC, USA *These authors have contributed equally to this work Abstract: Parenteral routes of drug administration are often selected to optimize actual dose of drug delivered, assure high bioavailability, bypass first-pass metabolism or harsh gastrointestinal environments, as well as maximize the speed of onset. Intramuscular (IM delivery can be preferred to intravenous delivery when initiating intravenous access is difficult or impossible. Drugs can be injected intramuscularly using a syringe or an automated delivery device (autoinjector. Investigation into the IM delivery dynamics of these methods may guide further improvements in the performance of injection technologies. Two porcine model studies were conducted to compare differences in dispersion of injectate volume for different methods of IM drug administration. The first study compared the differences in the degree of dispersion and uptake of injectate following the use of a manual syringe and an autoinjector. The second study compared the spatial spread of the injected formulation, or dispersion volume, and uptake of injectate following the use of five different autoinjectors (EpiPen® [0.3 mL], EpiPen® Jr [0.3 mL], Twinject® [0.15 mL, 0.3 mL], and Anapen® 300 [0.3 mL] with varying needle length, needle gauge, and force applied to the plunger. In the first study, the autoinjector provided higher peak volumes of injectate, indicating a greater degree of dispersion, compared with manual syringe delivery. In the second study, EpiPen autoinjectors resulted in larger dispersion volumes and higher initial dispersion ratios, which decreased rapidly over time, suggesting a greater

  7. Catalysing low cost green technologies for sustainable water service delivery in Kenya: Feasibility Study Report

    DEFF Research Database (Denmark)

    Ndirangu, Wangai; Schaer, Caroline

    2017-01-01

    Since 1974, the government of Kenya has recognised water supplies as critical for poverty reduction and development. Kenya’s economic and social development Vision 2030 emphasises the need for adequate and sustainable provision of water supply and sanitation services, with a target to achieve...... universal access by 2030. However, thus far most water development targets have not been achieved. Improvement has been much slower in rural and low income urban areas, and the current funding level is inadequate to achieve universal access by 2030. Over the years, official effort have been complemented...... to planning, standards and operations and maintenance, including source and cost of energy in rural and peri-urban water supplies is a key challenge to functionality and sustainability....

  8. The post-2015 delivery of universal and sustainable access to infrastructure services. Working Paper

    Energy Technology Data Exchange (ETDEWEB)

    Doczi, Julian, Dorr, Tobias; Mason, Nathaniel; Scott, Andrew

    2013-06-15

    In this new working paper, the authors focus specifically on what would be necessary to achieve High Level Panel-style goals and targets for water, energy and transport, if these were to be eventually adopted by world leaders. In all three cases, much of the advocacy - and the proposed High Level Panel goals - have emphasized the need to strive for universal and sustainable access to at least basic levels of services from these sectors. Many of the proposals for post-2015 goals and targets appear ambitious, but what would it take to achieve them? This paper assesses what is needed to achieve goals for universal and sustainable access to infrastructure, specifically water, energy and transport. Using illustrative goals and targets, the paper reviews the development challenges in each sector, and what will be necessary to overcome the barriers to universal and sustainable access to water, energy and transport infrastructure services, in the areas of governance, finance, capacity development and environmental protection. The paper ends with general conclusions about infrastructure in the post-2015 development agenda.

  9. Enhanced acute anti-inflammatory effects of CORM-2-loaded nanoparticles via sustained carbon monoxide delivery.

    Science.gov (United States)

    Qureshi, Omer Salman; Zeb, Alam; Akram, Muhammad; Kim, Myung-Sic; Kang, Jong-Ho; Kim, Hoo-Seong; Majid, Arshad; Han, Inbo; Chang, Sun-Young; Bae, Ok-Nam; Kim, Jin-Ki

    2016-11-01

    The aim of this study was to enhance the anti-inflammatory effects of carbon monoxide (CO) via sustained release of CO from carbon monoxide-releasing molecule-2-loaded lipid nanoparticles (CORM-2-NPs). CORM-2-NPs were prepared by hot high pressure homogenization method using trilaurin as a solid lipid core and Tween 20/Span 20/Myrj S40 as surfactant mixture. The physicochemical properties of CORM-2-NPs were characterized and CO release from CORM-2-NPs was assessed by myoglobin assay. In vitro anti-inflammatory effects were evaluated by nitric oxide assay in lipopolysaccharide-stimulated RAW 264.7 macrophages. In vivo anti-inflammatory activity was investigated by measuring paw volumes and histological examination in carrageenan-induced rat paw edema. Spherical CORM-2-NPs were around 100nm with narrow particle size distribution. The sustained CO release from CORM-2-NPs was observed and the half-life of CO release increased up to 10 times compared with CORM-2 solution. CORM-2-NPs showed enhanced in vitro anti-inflammatory effects by inhibition of nitric oxide production. Edema volume in rat paw was significantly reduced after treatment with CORM-2-NPs. Taken together, CORM-2-NPs have a great potential for CO therapeutics against inflammation via sustained release of CO. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Development of smart hydrogels of etherified gum ghatti for sustained oral delivery of ropinirole hydrochloride.

    Science.gov (United States)

    Ray, Somasree; Roy, Goutam; Maiti, Sabyasachi; Bhattacharyya, Uttam Kumar; Sil, Ayantika; Mitra, Ritwika

    2017-10-01

    Gum Ghatti (GG) is a water soluble complex polysaccharide obtained from Anogeissus latifolia. Due to its non toxic and excellent emulsifying characteristics, it was widely used in different pharmaceutical preparations. Currently another facet was explored for its utility as release retardant polymer in oral controlled drug delivery system. As GG solely was incapable of forming microspheres therefore modification of GG to Sodium carboxymethyl (NaCMGG) derivative was done by carboxymethylation process and its gel forming capacity was explored by the use of trivalent cation (Aluminium chloride) which results into complete microbead system in a complete aqueous environment for controlled delivery of Ropinirole Hydrochloride (RHCl). Rheological property of NaCMGG showed pseudoplastic shear thinning behavior. Spherical shape of bead was observed under scanning electron microscope. Depending upon the formulation variables, Drug entrapment efficiency (DEE) varies from 47.66±3.51 % to 71.4±2.65%., and 80 to 90% drug was released in 6h in pH 6.8 phosphate buffer. Drug release was governed by both fickian diffusion and polymer relaxation simultaneously. Compatible environment for drug entrapment was established by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). Thus the modified derivative NaCMGG could be a promising polymer in biomedical application. Copyright © 2017. Published by Elsevier B.V.

  11. Development and in vitro characterization of floating sustained-release drug delivery systems of polyphenols.

    Science.gov (United States)

    Rosenzweig, Ohad; Lavy, Eran; Gati, Irith; Kohen, Ron; Friedman, Michael

    2013-01-01

    The aim of this study was to develop and characterize floating stomach-retentive matrix tablets that will deliver polyphenols in a controlled release manner. The tablets were prepared by direct compression. A number of polymers were examined and egg albumin was chosen in light of a better performance in terms of floating behavior and decomposition time. Dissolution studies for three representative polyphenols loaded into a number of formulations were performed using the "f₂" factor in order to compare release profiles of different polyphenols and formulations. The release data showed a good fit into the power law equation and zero-order kinetics has been determined for some of the systems. Erosion and textural analysis studies revealed that higher concentration of egg albumin results in a higher gel strength that is less susceptible to erosion, potentially leading to a prolonged delivery time of drug. The ability of egg albumin-based tablets to resist high mechanical forces was also determined, while comparison to cellulose-derived polymers revealed that the latter have a much lower ability to resist the same forces. The developed delivery system has the potential to increase the efficacy of the therapy for various pathological stomach conditions and to improve patient compliance.

  12. Neutron production from beam-modifying devices in a modern double scattering proton therapy beam delivery system

    Science.gov (United States)

    Pérez-Andújar, Angélica; Newhauser, Wayne D; DeLuca, Paul M

    2014-01-01

    In this work the neutron production in a passive beam delivery system was investigated. Secondary particles including neutrons are created as the proton beam interacts with beam shaping devices in the treatment head. Stray neutron exposure to the whole body may increase the risk that the patient develops a radiogenic cancer years or decades after radiotherapy. We simulated a passive proton beam delivery system with double scattering technology to determine the neutron production and energy distribution at 200 MeV proton energy. Specifically, we studied the neutron absorbed dose per therapeutic absorbed dose, the neutron absorbed dose per source particle and the neutron energy spectrum at various locations around the nozzle. We also investigated the neutron production along the nozzle's central axis. The absorbed doses and neutron spectra were simulated with the MCNPX Monte Carlo code. The simulations revealed that the range modulation wheel (RMW) is the most intense neutron source of any of the beam spreading devices within the nozzle. This finding suggests that it may be helpful to refine the design of the RMW assembly, e.g., by adding local shielding, to suppress neutron-induced damage to components in the nozzle and to reduce the shielding thickness of the treatment vault. The simulations also revealed that the neutron dose to the patient is predominated by neutrons produced in the field defining collimator assembly, located just upstream of the patient. PMID:19147903

  13. Immediate Postpartum Intrauterine Contraceptive Device Insertions in Caesarean and Vaginal Deliveries: A Comparative Study of Follow-Up Outcomes

    Directory of Open Access Journals (Sweden)

    Reetu Hooda

    2016-01-01

    Full Text Available Background. Immediate postpartum intrauterine contraceptive device (IPPIUCD is a lucrative postpartum family planning method which provides effective reversible contraception to women in the delivery setting. Our aim was to study the clinical outcomes of IPPIUCD insertions and compare them as a factor of route of insertion (vaginal versus caesarean. Methods. This is a retrospective analytical study done in a tertiary care teaching institute. A Cohort of 593 vaginal and caesarean deliveries with IPPIUCD insertions, over a two-year period, was studied and compared for follow-up results. Outcome measures were safety (perforation, irregular bleeding, unusual vaginal discharge, and infection, efficacy (pregnancy, expulsions, and discontinuations, and incidence of undescended IUCD strings. Descriptives were calculated for various outcomes and chi square tests were used for comparison in between categorical variables. Results. Overall complication rates were low. No case of perforation or pregnancy was reported. Spontaneous expulsions were present in 5.3% cases and were significantly higher in vaginal insertions (p=0.042. The incidence of undescended strings was high (38%, with highly significant difference between both groups (p=0.000. Conclusion. IPPIUCD is a strong weapon in the family planning armoury and should be encouraged in both vaginal and caesarean deliveries. Early follow-up should be encouraged to detect expulsions and tackle common problems.

  14. Moving Evidence into Practice: Cost Analysis and Assessment of Macaques’ Sustained Behavioral Engagement with Videogames and Foraging Devices

    Science.gov (United States)

    Bennett, Allyson J.; Perkins, Chaney M.; Tenpas, Parker D.; Reinebach, Alma L.; Pierre, Peter J.

    2017-01-01

    Environmental enrichment plans for captive nonhuman primates often include provision of foraging devices. The rationale for using foraging devices is to promote species-typical activity patterns that encourage physical engagement and provide multi-sensory stimulation. However, these devices have been shown to be ineffective at sustaining manipulation over long periods of time, and often produce minimal cognitive engagement. Here we use an evidence-based approach to directly compare the amount of object-directed behavior with a foraging device and a computer-based videogame system. We recorded 11adult male rhesus monkeys’ interactions with a foraging device and two tasks within a joystick videogame cognitive test battery. Both techniques successfully produced high levels of engagement during the initial 20-min of observation. After 1-hr the monkeys manipulated the foraging device significantly less than the joystick, F(2,10)= 43.93, p videogame play for the majority of a 5-hr period, provided that they received a 94mg chow pellet upon successful completion of trials. Using a model approach we developed previously as a basis for standardized cost:benefit analysis to inform facility decisions, we calculated the comprehensive cost of incorporating a videogame system as an enrichment strategy. The videogame system has a higher initial cost compared to widely-used foraging devices however, the ongoing labor and supply costs are relatively low. Our findings add to two decades of empirical studies by a number of laboratories that have demonstrated the successful use of videogame-based systems to promote sustained non-social cognitive engagement for macaques. The broader significance of the work lies in the application of a systematic approach to compare and contrast enrichment strategies and encourage evidence-based decision making when choosing an enrichment strategy in a manner that promotes meaningful cognitive enrichment to the animals. PMID:27404766

  15. Moving evidence into practice: cost analysis and assessment of macaques' sustained behavioral engagement with videogames and foraging devices.

    Science.gov (United States)

    Bennett, Allyson J; Perkins, Chaney M; Tenpas, Parker D; Reinebach, Alma L; Pierre, Peter J

    2016-12-01

    Environmental enrichment plans for captive nonhuman primates often include provision of foraging devices. The rationale for using foraging devices is to promote species-typical activity patterns that encourage physical engagement and provide multi-sensory stimulation. However, these devices have been shown to be ineffective at sustaining manipulation over long periods of time, and often produce minimal cognitive engagement. Here we use an evidence-based approach to directly compare the amount of object-directed behavior with a foraging device and a computer-based videogame system. We recorded 11 adult male rhesus monkeys' interactions with a foraging device and two tasks within a joystick videogame cognitive test battery. Both techniques successfully produced high levels of engagement during the initial 20 min of observation. After 1 hr the monkeys manipulated the foraging device significantly less than the joystick, F(2,10) = 43.93, P videogame play for the majority of a 5 hr period, provided that they received a 94 mg chow pellet upon successful completion of trials. Using a model approach, we developed previously as a basis for standardized cost:benefit analysis to inform facility decisions, we calculated the comprehensive cost of incorporating a videogame system as an enrichment strategy. The videogame system has a higher initial cost compared to widely-used foraging devices, however, the ongoing labor and supply costs are relatively low. Our findings add to two decades of empirical studies by a number of laboratories that have demonstrated the successful use of videogame-based systems to promote sustained non-social cognitive engagement for macaques. The broader significance of the work lies in the application of a systematic approach to compare and contrast enrichment strategies and encourage evidence-based decision making when choosing an enrichment strategy in a manner that promotes meaningful cognitive enrichment to the animals. © 2016 Wiley

  16. The traditional method of oral as-needed pain medication delivery compared to an oral patient-controlled analgesia device following total knee arthroplasty.

    Science.gov (United States)

    Lambert, Teresa L; Cata, Denise M

    2014-01-01

    As-needed (PRN) oral pain medication is an essential part of multimodal pain therapy. Medication delivery is often delayed because of multiple demands upon nursing time in a busy postoperative nursing unit. Postoperative pain control was compared using either the manual delivery of PRN oral pain medication or a bedside oral patient-controlled analgesia device. Thirty patients in each group completed a survey on the day of discharge, and additional data were collected by chart reviews. Device patients had significantly better pain scores than the usual care group on postoperative Day 2 and within the last 24 hours prior to discharge. The device group reported statistically less pain interference overall with general activity, mood, physical therapy, sleep, and appetite. Use of an oral patient-controlled analgesia device may improve pain management and patient function following total knee arthroplasty compared to the traditional delivery of oral PRN pain medication.

  17. Assessing a commercially available sports drink on exogenous carbohydrate oxidation, fluid delivery and sustained exercise performance.

    Science.gov (United States)

    Roberts, Justin D; Tarpey, Michael D; Kass, Lindsy S; Tarpey, Richard J; Roberts, Michael G

    2014-03-04

    Whilst exogenous carbohydrate oxidation (CHOEXO) is influenced by mono- and disaccharide combinations, debate exists whether such beverages enhance fluid delivery and exercise performance. Therefore, this study aimed to ascertain CHOEXO, fluid delivery and performance times of a commercially available maltodextrin/ fructose beverage in comparison to an isocaloric maltodextrin beverage and placebo. Fourteen club level cyclists (age: 31.79 ± 10.02 years; height: 1.79 ± 0.06 m; weight: 73.69 ± 9.24 kg; VO2max: 60.38 ± 9.36 mL · kg·-1 min-1) performed three trials involving 2.5 hours continuous exercise at 50% maximum power output (Wmax: 176.71 ± 25.92 W) followed by a 60 km cycling performance test. Throughout each trial, athletes were randomly assigned, in a double-blind manner, either: (1) 1.1 g · min-1 maltodextrin + 0.6 g · min-1 fructose (MD + F), (2) 1.7 g · min-1 of maltodextrin (MD) or (3) flavoured water (P). In addition, the test beverage at 60 minutes contained 5.0 g of deuterium oxide (2H2O) to assess quantification of fluid delivery. Expired air samples were analysed for CHOEXO according to the 13C/12C ratio method using gas chromatography continuous flow isotope ratio mass spectrometry. Peak CHOEXO was significantly greater in the final 30 minutes of submaximal exercise with MD + F and MD compared to P (1.45 ± 0.09 g · min-1, 1.07 ± 0.03 g · min-1and 0.00 ± 0.01 g · min-1 respectively, P Performance times significantly improved with MD + F compared with both MD (by 7 min 22 s ± 1 min 56 s, or 7.2%) and P (by 6 min 35 s ± 2 min 33 s, or 6.5%, P performance times.

  18. Minimally invasive delivery of a novel direct epicardial assist device in a porcine heart failure model.

    Science.gov (United States)

    McGarvey, Jeremy R; Shimaoka, Toru; Takebayashi, Satoshi; Aoki, Chikashi; Kondo, Norihiro; Takebe, Manabu; Zsido, Gerald A; Jassar, Arminder; Gorman, Joseph H; Pilla, James J; Gorman, Robert C

    2014-01-01

    Despite advances in design, modern ventricular assist device placement involves median sternotomy and cardiopulmonary bypass and is associated with infectious/embolic complications. In this study, we examine the feasibility and function of a novel minimally invasive, non-blood-contacting epicardial assist device in a porcine ischemic cardiomyopathy model. Feasibility was first tested in an ex vivo thoracoscopic trainer box with slaughterhouse hearts. Five male Yorkshire swine underwent selective ligation of the circumflex artery to create a posterolateral infarct Twelve weeks after infarct, all animals underwent left minithoracotomy. A custom inflatable bladder was positioned over the epicardial surface of the infarct and firmly secured to the surrounding border zone myocardium with polypropylene mesh and minimally invasive mesh tacks. An external gas pulsation system actively inflated and deflated the bladder in synchrony with the cardiac cycle. All animals then underwent cardiac magnetic resonance imaging to assess ventricular function. All subjects successfully underwent off-pump placement of the epicardial assist device via minithoracotomy. Ejection fraction significantly improved from 29.1% ± 4.8% to 39.6% ± 4.23% (P porcine ischemic cardiomyopathy model and may provide a safe alternative to currently available ventricular assist device therapies. Further, the technique used for device positioning and fixation suggests that an entirely thoracoscopic approach is possible.

  19. Pharmacokinetic profile of a sustained-delivery system for physostigmine in rats

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Donna [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore); Zhao Bin [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore); Moochhala, Shabbir [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore)]. E-mail: mshabbir@dso.org.sg; Yang Yiyan [Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, 04-01, Singapore 138669 (Singapore)

    2006-07-25

    Physostigmine (PHY) is involved in clinical treatments of glaucoma, Alzheimer's disease and has been suggested as an alternative prophylactic treatment against organophosphate poisoning. However, one of the therapeutic uses of physostigmine is limited by short elimination half-life. In this study, PHY-loaded microparticles, prepared by a spray-drying method with biodegradable poly(D,L-lactide-co-glycolide) (PLGA) with a size ranging from 1 to 5 {mu}M was developed on a sustained release preparation to prevent multiple dosing and yet maintaining constant plasma level. The release of PHY-loaded microparticles was characterized in vitro and in vivo after oral administration in Sprague-Dawley rats. After oral administration of physostigmine-loaded microparticles in rats, the time course of physostigmine in blood plasma was followed over 48 h and samples were analysed using a validated high-performance liquid chromatography (HPLC) assay. In the pharmacokinetics profile of physostigmine for the elimination half-life and area-under-curve, PHY release was sustained in vitro for over 1 week with a low initial burst release. The pharmacokinetics results show a 15-fold increase in the elimination half-life of physostigmine microparticle formulation, coupled with a larger area under the concentration-time curve (AUC), without affecting the peak concentration and the latency to peak concentration, when compared to the standard formulation.

  20. Sustained delivery of latanoprost by thermosensitive chitosan-gelatin-based hydrogel for controlling ocular hypertension.

    Science.gov (United States)

    Cheng, Yung-Hsin; Hung, Kuo-Hsuan; Tsai, Tung-Hu; Lee, Chia-Jung; Ku, Ruy-Yu; Chiu, Allen Wen-Hsiang; Chiou, Shih-Hwa; Liu, Catherine Jui-Ling

    2014-10-01

    Glaucoma is an irreversible ocular disease that may lead to progressive visual field loss and eventually to blindness with inadequately controlled intraocular pressure (IOP). Latanoprost is one of the most potent ocular hypotensive compounds, the current first-line therapy in glaucoma. However, the daily instillation required for efficacy and undesirable side-effects are major causes of treatment adherence failure and persistence in glaucoma therapy. In the present study, we developed an injectable thermosensitive chitosan/gelatin/glycerol phosphate (C/G/GP) hydrogel as a sustained-release system of latanoprost for glaucoma treatment. The latanoprost-loaded C/G/GP hydrogel can gel within 1min at 37°C. The results show a sustained release of latanoprost from C/G/GP hydrogel in vitro and in vivo. The latanoprost-loaded C/G/GP hydrogel showed a good in vitro and in vivo biocompatibility. A rabbit model of glaucoma was established by intravitreal injection of triamcinolone acetonide. After a single subconjunctival injection of latanoprost-loaded C/G/GP hydrogel, IOP was significantly decreased within 8days and then remained at a normal level. The results of the study suggest that latanoprost-loaded C/G/GP hydrogel may have a potential application in glaucoma therapy. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Microspheres made of poly(epsilon-caprolactone)-based amphiphilic copolymers: potential in sustained delivery of proteins.

    Science.gov (United States)

    Quaglia, Fabiana; Ostacolo, Luisanna; Nese, Giuseppe; De Rosa, Giuseppe; La Rotonda, Maria Immacolata; Palumbo, Rosario; Maglio, Giovanni

    2005-10-20

    Microspheres of amphiphilic multi-block poly(ester-ether)s (PEE)s and poly(ester-ether-amide)s (PEEA)s based on poly(epsilon-caprolactone) (PCL) were investigated as delivery systems for proteins. The interest was mainly focused on the effect of their molecular structure and composition on the overall properties of the microspheres, encapsulating bovine serum albumin (BSA) as a model protein. PEEs and PEEAs were prepared using a alpha,omega-dihydroxy-terminated PCL macromer (Mn= 2.0 kDa) as a hydrophobic component. Hydrophilic oxyethylene sequences were generated using poly(ethylene oxide)s (PEO)s of different molecular mass (Mn= 300-600 Da) in the case of PEEs, or 4,7,10-trioxa-1,13-tridecanediamine (Trioxy) and PEO150 (Mn= 150 Da) in the case of PEEAs. The copolymers showed a decrease of Tm and crystallinity values as compared with PCL. Within each class of copolymers, the bulk hydrophilicity increased with increasing the number of oxyethylene groups in the chain repeat unit. PEEAs were more hydrophilic than PEEs with a similar number of oxyethylene groups. Discrete spherical particles were prepared by both PEEs and PEEAs and their BSA encapsulation efficiency related to copolymer properties. Interestingly, the insertion of short hydrophilic segments is enough to significantly affect protein distribution inside microspheres and its release profiles, as compared to PCL microspheres. Different degradation rates and mechanisms were observed for copolymer microspheres, mainly depending on the distribution of oxyethylene units along the chain. The results highlight that a fine control over the structural parameters of amphiphilic PCL-based multi-block copolymers is a key factor for their application in the field of protein delivery.

  2. Sustainability of a community-based anti-retroviral care delivery model - a qualitative research study in Tete, Mozambique.

    Science.gov (United States)

    Rasschaert, Freya; Decroo, Tom; Remartinez, Daniel; Telfer, Barbara; Lessitala, Faustino; Biot, Marc; Candrinho, Baltazar; Van Damme, Wim

    2014-01-01

    To overcome patients' reported barriers to accessing anti-retroviral therapy (ART), a community-based delivery model was piloted in Tete, Mozambique. Community ART Groups (CAGs) of maximum six patients stable on ART offered cost- and time-saving benefits and mutual psychosocial support, which resulted in better adherence and retention outcomes. To date, Médecins Sans Frontières has coordinated and supported these community-driven activities. To better understand the sustainability of the CAG model, we developed a conceptual framework on sustainability of community-based programmes. This was used to explore the data retrieved from 16 focus group discussions and 24 in-depth interviews with different stakeholder groups involved in the CAG model and to identify factors influencing the sustainability of the CAG model. We report the findings according to the framework's five components. (1) The CAG model was designed to overcome patients' barriers to ART and was built on a concept of self-management and patient empowerment to reach effective results. (2) Despite the progressive Ministry of Health (MoH) involvement, the daily management of the model is still strongly dependent on external resources, especially the need for a regulatory cadre to form and monitor the groups. These additional resources are in contrast to the limited MoH resources available. (3) The model is strongly embedded in the community, with patients taking a more active role in their own healthcare and that of their peers. They are considered as partners in healthcare, which implies a new healthcare approach. (4) There is a growing enabling environment with political will and general acceptance to support the CAG model. (5) However, contextual factors, such as poverty, illiteracy and the weak health system, influence the community-based model and need to be addressed. The community embeddedness of the model, together with patient empowerment, high acceptability and progressive MoH involvement

  3. Bimatoprost-loaded ocular inserts as sustained release drug delivery systems for glaucoma treatment: in vitro and in vivo evaluation.

    Directory of Open Access Journals (Sweden)

    Juçara Ribeiro Franca

    Full Text Available The purpose of the present study was to develop and assess a novel sustained-release drug delivery system of Bimatoprost (BIM. Chitosan polymeric inserts were prepared using the solvent casting method and characterized by swelling studies, infrared spectroscopy, differential scanning calorimetry, drug content, scanning electron microscopy and in vitro drug release. Biodistribution of 99mTc-BIM eye drops and 99mTc-BIM-loaded inserts, after ocular administration in Wistar rats, was accessed by ex vivo radiation counting. The inserts were evaluated for their therapeutic efficacy in glaucomatous Wistar rats. Glaucoma was induced by weekly intracameral injection of hyaluronic acid. BIM-loaded inserts (equivalent to 9.0 µg BIM were administered once into conjunctival sac, after ocular hypertension confirmation. BIM eye drop was topically instilled in a second group of glaucomatous rats for 15 days days, while placebo inserts were administered once in a third group. An untreated glaucomatous group was used as control. Intraocular pressure (IOP was monitored for four consecutive weeks after treatment began. At the end of the experiment, retinal ganglion cells and optic nerve head cupping were evaluated in the histological eye sections. Characterization results revealed that the drug physically interacted, but did not chemically react with the polymeric matrix. Inserts sustainedly released BIM in vitro during 8 hours. Biodistribution studies showed that the amount of 99mTc-BIM that remained in the eye was significantly lower after eye drop instillation than after chitosan insert implantation. BIM-loaded inserts lowered IOP for 4 weeks, after one application, while IOP values remained significantly high for the placebo and untreated groups. Eye drops were only effective during the daily treatment period. IOP results were reflected in RGC counting and optic nerve head cupping damage. BIM-loaded inserts provided sustained release of BIM and seem to be a

  4. Surgical membranes as directional delivery devices to generate tissue: testing in an ovine critical sized defect model.

    Directory of Open Access Journals (Sweden)

    Melissa L Knothe Tate

    Full Text Available PURPOSE: Pluripotent cells residing in the periosteum, a bi-layered membrane enveloping all bones, exhibit a remarkable regenerative capacity to fill in critical sized defects of the ovine femur within two weeks of treatment. Harnessing the regenerative power of the periosteum appears to be limited only by the amount of healthy periosteum available. Here we use a substitute periosteum, a delivery device cum implant, to test the hypothesis that directional delivery of endogenous periosteal factors enhances bone defect healing. METHODS: Newly adapted surgical protocols were used to create critical sized, middiaphyseal femur defects in four groups of five skeletally mature Swiss alpine sheep. Each group was treated using a periosteum substitute for the controlled addition of periosteal factors including the presence of collagen in the periosteum (Group 1, periosteum derived cells (Group 2, and autogenic periosteal strips (Group 3. Control group animals were treated with an isotropic elastomer membrane alone. We hypothesized that periosteal substitute membranes incorporating the most periosteal factors would show superior defect infilling compared to substitute membranes integrating fewer factors (i.e. Group 3>Group 2>Group 1>Control. RESULTS: Based on micro-computed tomography data, bone defects enveloped by substitute periosteum enabling directional delivery of periosteal factors exhibit superior bony bridging compared to those sheathed with isotropic membrane controls (Group 3>Group 2>Group 1, Control. Quantitative histological analysis shows significantly increased de novo tissue generation with delivery of periosteal factors, compared to the substitute periosteum containing a collagen membrane alone (Group 1 as well as compared to the isotropic control membrane. Greatest tissue generation and maximal defect bridging was observed when autologous periosteal transplant strips were included in the periosteum substitute. CONCLUSION: Periosteum

  5. Injectable supramolecular hydrogel formed from α-cyclodextrin and PEGylated arginine-functionalized poly(l-lysine) dendron for sustained MMP-9 shRNA plasmid delivery.

    Science.gov (United States)

    Lin, Qianming; Yang, Yumeng; Hu, Qian; Guo, Zhong; Liu, Tao; Xu, Jiake; Wu, Jianping; Kirk, Thomas Brett; Ma, Dong; Xue, Wei

    2017-02-01

    Hydrogels have attracted much attention in cancer therapy and tissue engineering due to their sustained gene delivery ability. To obtain an injectable and high-efficiency gene delivery hydrogel, methoxypolyethylene glycol (MPEG) was used to conjugate with the arginine-functionalized poly(l-lysine) dendron (PLLD-Arg) by click reaction, and then the synthesized MPEG-PLLD-Arg interacted with α-cyclodextrin (α-CD) to form the supramolecular hydrogel by the host-guest interaction. The gelation dynamics, hydrogel strength and shear viscosity could be modulated by α-CD content in the hydrogel. MPEG-PLLD-Arg was confirmed to bind and deliver gene effectively, and its gene transfection efficiency was significantly higher than PEI-25k under its optimized condition. After gelation, MMP-9 shRNA plasmid (pMMP-9) could be encapsulated into the hydrogel matrix in situ and be released from the hydrogels sustainedly, as the release rate was dependent on α-CD content. The released MPEG-PLLD-Arg/pMMP-9 complex still showed better transfection efficiency than PEI-25k and induced sustained tumor cell apoptosis. Also, in vivo assays indicated that this pMMP-9-loaded supramolecular hydrogel could result in the sustained tumor growth inhibition meanwhile showed good biocompatibility. As an injectable, sustained and high-efficiency gene delivery system, this supramolecular hydrogel is a promising candidate for long-term gene therapy. To realize the sustained gene delivery for gene therapy, a supramolecular hydrogel with high-efficiency gene delivery ability was prepared through the host-guest interaction between α-cyclodextrin and PEGylated arginine-functionalized poly(l-lysine) dendron. The obtained hydrogel was injectable and biocompatible with adjustable physicochemical property. More importantly, the hydrogel showed the high-efficiency and sustained gene transfection to our used cells, better than PEI-25k. The supramolecular hydrogel resulted in the sustained tumor growth

  6. Formulation and evaluation of sustained release enteric-coated pellets of budesonide for intestinal delivery.

    Science.gov (United States)

    Raval, Mihir K; Ramani, Riddhi V; Sheth, Navin R

    2013-10-01

    The aim of present work was to develop intestinal-targeted pellets of Budesonide, a potent glucocorticoid, used for the treatment of ulcerative colitis and Crohn's disease by extrusion and spheronization method. Current available oral formulations of Budesonide have low efficacy because of the premature drug release in the upper part of the gastrointestinal tract. In this study, a pH-controlled intestinal-targeted pellet of budesonide was established using 3(2) full factorial design by giving an enteric coating with Eudragit S100. Budesonide-sustained release pellets were prepared by extruder and spheronization technique using a combination of water-soluble and permeable polymers by applying 3(2) full factorial design. The pellets were coated by spray coating technique using Eudragit S100 as an enteric polymer. The pellets were characterized for its flowability, sphericity, friability, and in vitro drug release. Release behaviour was studied in different pH media. The release profile was studied for the mechanism of drug release. The optimized formulation showed negligible drug release in the stomach followed by release for 12 h in the intestinal pH. Differential scanning calorimetry and Fourier Transform Infrared Spectroscopy studies indicated no interaction between drug and polymer. Scanning Electron Microscopy image of coated pellets suggested a uniform and smooth coat over the surface of pellets. Accelerated stability studies showed a stable nature of drug in the formulation. All evaluation parameter showed that pellets were good in spherocity and flowability. Sustained release pellets of Budesonide could be prepared by extrusion and spheronization which released the drug in intestinal pH for an intestine to treat inflammatory bowel disease. A ratio of polymer combination could be decided using a full factorial design.

  7. A microfluidic device for monitoring siRNA delivery under fluid now

    NARCIS (Netherlands)

    van der Meer, Andries Dirk; Feijen, J.; Kamphuis, Marloes; Hennink, W.E.; Poot, Andreas A.; Sam, A.P.; Feijen, Jan; Vermes, I.

    2008-01-01

    When studying particle uptake in vitro, it is favorable to mimic the in vivo situation as much as possible. In this study we present a microfluidic device to mimic the mechanical stress caused by the flow of blood while studying particle uptake in vitro. Human endothelial cells were treated with

  8. Assessment of Selected Parameters of the Automatic Scarification Device as an Example of a Device for Sustainable Forest Management

    Directory of Open Access Journals (Sweden)

    Ryszard Tadeusiewicz

    2017-12-01

    Full Text Available Due to technological progress in forestry, seedlings with covered root systems—especially those grown in container nurseries—have become increasingly important in forest nursery production. One the trees that is most commonly grown this way is the common oak (Quercus robur L.. For an acorn to be sown in a container, it is necessary to remove its upper part during mechanical scarification, and evaluate its sowing suitability. At present, this is mainly done manually and by visual assessment. The low effectiveness of this method of acorn preparation has encouraged a search for unconventional solutions. One of them is the use of an automated device that consists of a computer vision-based module. For economic reasons related to the cost of growing seedlings in container nurseries, it is beneficial to minimize the contribution of unhealthy seeds. The maximum accuracy, which is understood as the number of correct seed diagnoses relative to the total number of seeds being assessed, was adopted as a criterion for choosing a separation threshold. According to the method proposed, the intensity and red components of the images of scarified acorns facilitated the best results in terms of the materials examined during the experiment. On average, a 10% inaccuracy of separation was observed. A secondary outcome of the presented research is an evaluation of the ergonomic parameters of the user interface that is attached to the unit controlling the device when it is running in its autonomous operation mode.

  9. Exposure to Electronic Nicotine Delivery Device (ENDS) Visual Imagery Increases Smoking Urge and Desire

    OpenAIRE

    King, Andrea C.; Smith, Lia J.; Fridberg, Daniel J.; Matthews, Alicia K.; McNamara, Patrick J; Cao, Dingcai

    2015-01-01

    Use and awareness of electronic nicotine delivery systems (ENDS; also known as electronic cigarettes or e-cigarettes) has increased rapidly in recent years, particularly among young adults. As use of ENDS resembles traditional smoking in both hand to mouth movements and inhalation and exhalation behaviors, we determined whether exposure to e-cigarette use via video exposure would act as a cue to elicit urge and desire for a combustible cigarette. Young adult smokers (mean age 26.3 ± 4.1 years...

  10. Poly(N-isopropylacrylamide Hydrogels for Storage and Delivery of Reagents to Paper-Based Analytical Devices

    Directory of Open Access Journals (Sweden)

    Haydn T. Mitchell

    2015-07-01

    Full Text Available The thermally responsive hydrogel N,N'-methylenebisacrylamide-cross-linked poly(N-isopropylacrylamide (PNIPAM was developed and evaluated as a reagent storage and delivery system for microfluidic paper-based analytical devices (microPADs. PNIPAM was shown to successfully deliver multiple solutions to microPADs in specific sequences or simultaneously in laminar-flow configuration and was found to be suitable for delivering four classes of reagents to the devices: Small molecules, enzymes, antibodies and DNA. PNIPAM was also able to successfully deliver a series of standard glucose solutions to microPADs equipped to perform a colorimetric glucose assay. The results of these tests were used to produce an external calibration curve, which in turn was used to determine the concentration of glucose in sample solutions. Finally, PNIPAM was used to store the enzyme horseradish peroxidase for 35 days under ambient conditions with no significant loss of activity. The combination of PNIPAM and microPADs may allow for more complex assays to be performed on paper-based devices, facilitate the preparation of external calibration curves in the field, and extend the shelf life of microPADs by stabilizing reagents in an easy-to-use format.

  11. Packaged water: optimizing local processes for sustainable water delivery in developing nations

    Directory of Open Access Journals (Sweden)

    Dada Ayokunle C

    2011-07-01

    Full Text Available Abstract With so much global attention and commitment towards making the Water and Sanitation targets of the Millennium Development Goals (MDGs a reality, available figures seem to speak on the contrary as they reveal a large disparity between the expected and what currently obtains especially in developing countries. As studies have shown that the standard industrialized world model for delivery of safe drinking water technology may not be affordable in much of the developing world, packaged water is suggested as a low cost, readily available alternative water provision that could help bridge the gap. Despite the established roles that this drinking water source plays in developing nations, its importance is however significantly underestimated, and the source considered unimproved going by 'international standards'. Rather than simply disqualifying water from this source, focus should be on identifying means of improvement. The need for intervening global communities and developmental organizations to learn from and build on the local processes that already operate in the developing world is also emphasized. Identifying packaged water case studies of some developing nations, the implication of a tenacious focus on imported policies, standards and regulatory approaches on drinking water access for residents of the developing world is also discussed.

  12. Well-defined degradable brush polymer-drug conjugates for sustained delivery of Paclitaxel.

    Science.gov (United States)

    Yu, Yun; Chen, Chih-Kuang; Law, Wing-Cheung; Mok, Jorge; Zou, Jiong; Prasad, Paras N; Cheng, Chong

    2013-03-04

    To achieve a conjugated drug delivery system with high drug loading but minimal long-term side effects, a degradable brush polymer-drug conjugate (BPDC) was synthesized through azide-alkyne click reaction of acetylene-functionalized polylactide (PLA) with azide-functionalized paclitaxel (PTXL) and poly(ethylene glycol) (PEG). Well-controlled structures of the resulting BPDC and its precursors were verified by (1)H NMR and gel permeation chromatography (GPC) characterizations. With nearly quantitative click efficiency, drug loading amount of the BPDC reached 23.2 wt %. Both dynamic light scattering (DLS) analysis and transmission electron microscopy (TEM) imaging indicated that the BPDC had a nanoscopic size around 10-30 nm. The significant hydrolytic degradability of the PLA backbone of the BPDC was confirmed by GPC analysis of its incubated solution. Drug release study showed that PTXL moieties can be released through the cleavage of the hydrolyzable conjugation linkage in pH 7.4 at 37 °C, with 50% release in about 22 h. As illustrated by cytotoxicity study, while the polymeric scaffold of the BPDC is nontoxic, the BPDC exhibited higher therapeutic efficacy toward MCF-7 cancer cells than free PTXL at 0.1 and 1 μg/mL. Using Nile red as encapsulated fluorescence probe, cell uptake study showed effective internalization of the BPDC into the cells.

  13. Sustained Correction of Motoneuron Histopathology Following Intramuscular Delivery of AAV in Pompe Mice

    Science.gov (United States)

    ElMallah, Mai K; Falk, Darin J; Nayak, Sushrusha; Federico, Roland A; Sandhu, Milapjit S; Poirier, Amy; Byrne, Barry J; Fuller, David D

    2014-01-01

    Pompe disease is an autosomal recessive disorder caused by mutations in the acid-α glucosidase (GAA) gene. Lingual dysfunction is prominent but does not respond to conventional enzyme replacement therapy (ERT). Using Pompe (Gaa−/−) mice, we tested the hypothesis that intralingual delivery of viral vectors encoding GAA results in GAA expression and glycogen clearance in both tongue myofibers and hypoglossal (XII) motoneurons. An intralingual injection of an adeno-associated virus (AAV) vector encoding GAA (serotypes 1 or 9; 1 × 1011 vector genomes, CMV promoter) was performed in 2-month-old Gaa−/− mice, and tissues were harvested 4 months later. Both serotypes robustly transduced tongue myofibers with histological confirmation of GAA expression (immunochemistry) and glycogen clearance (Period acid-Schiff stain). Both vectors also led to medullary transgene expression. GAA-positive motoneurons did not show the histopathologic features which are typical in Pompe disease and animal models. Intralingual injection with the AAV9 vector resulted in approximately threefold more GAA-positive XII motoneurons (P GAA expression in tongue myofibers and motoneurons, but AAV9 may more effectively target motoneurons. PMID:24336173

  14. Heparinized collagen sutures for sustained delivery of PDGF-BB: Delivery profile and effects on tendon-derived cells In-Vitro.

    Science.gov (United States)

    Younesi, Mousa; Donmez, Baris Ozgur; Islam, Anowarul; Akkus, Ozan

    2016-09-01

    term studies are needed to confirm whether this proliferation is outweighs the moderate reduction in the expression of tendon-associated genes. A mechanically robust pure collagen suture was fabricated via linear electrocompaction and conjugated with heparin for prolonged delivery of PDFG-BB. Sustained delivery of the PDGF-BB improved the proliferation of tendon derived cells substantially at the expense of a moderate downregulation of tenogenic markers. The collagen threads were functionally applicable as epitendinous sutures when applied to chicken flexor tendons in vitro. Overall, electrocompacted collagen sutures holds potential to improve repair outcome in flexor tendon surgeries by improving cellularity and collagen production through delivery of the PDGF-BB. The bioinductive suture concept can be applied to deliver other growth factors for a wide-array of applications. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Sustained Local Delivery of siRNA from an Injectable Scaffold

    Science.gov (United States)

    Nelson, Christopher E.; Gupta, Mukesh K.; Adolph, Elizabeth J.; Shannon, Joshua M.; Guelcher, Scott A.; Duvall, Craig L.

    2011-01-01

    Controlled gene silencing technologies have significant, unrealized potential for use in tissue regeneration applications. The design described herein provides a means to package and protect siRNA within pH-responsive, endosomolytic micellar nanoparticles (si-NPs) that can be incorporated into nontoxic, biodegradable, and injectable polyurethane (PUR) tissue scaffolds. The si-NPs were homogeneously incorporated throughout the porous PUR scaffolds, and they were shown to be released via a diffusion-based mechanism for over three weeks. The siRNA-loaded micelles were larger but retained nano particulate morphology of approximately 100 nm diameter following incorporation into and release from the scaffolds. PUR scaffold releasate collected in vitro in PBS at 37°C for 1–4 days was able to achieve dose-dependent siRNA-mediated silencing with approximately 50% silencing achieved of the model gene GAPDH in NIH3T3 mouse fibroblasts. This promising platform technology provides both a research tool capable of probing the effects of local gene silencing and a potentially high-impact therapeutic approach for sustained, local silencing of deleterious genes within tissue defects. PMID:22061489

  16. Sustained delivery of vincristine inside an orthotopic mouse sarcoma model decreases tumor growth.

    Science.gov (United States)

    Harris, Jamie C; Coburn, Jeannine M; Kajdacsy-Balla, Andre; Kaplan, David L; Chiu, Bill

    2016-12-01

    Sarcoma accounts for 20% of solid tumors in children. Surgery has significant morbidity. We hypothesized that delivering chemotherapy directly into tumors through sustained release silk systems could slow tumor growth. Human Ewing sarcoma cells A673 were cultured with vincristine and doxorubicin to determine half maximal inhibitory concentration (IC50). Cells were injected into mouse hind leg to create orthotopic tumors. Tumor volumes were measured using ultrasound. When volume reached >250mm(3,) interventions included: implantation of drug-free silk foam (Control-F), doxorubicin 400μg foam (Dox400-F), vincristine 50μg foam (Vin50-F), drug-free silk gel (Control-G), vincristine 50μg gel (Vin50-G), or single dose intravenous vincristine 50μg (Vin50-IV). End-point was volume>1000mm(3). Kaplan Meier and ANOVA were used. IC50 for vincristine and doxorubicin was 0.5ng/mL and 200ng/mL, respectively. There was no difference between Dox400-F [6±1days to end point (DTEP)] and Control-F (5±1.3 DTEP). Vin50-F (12.4±3.5 DTEP) had slower growth compared to Control-F (pinside the sarcoma tumor with silk gel decreased tumor growth. Applying this intratumoral treatment strategy may potentially decrease the extent of surgical excision. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Local sustained-release delivery systems of the antibiofilm agent thiazolidinedione-8 for prevention of catheter-associated urinary tract infections.

    Science.gov (United States)

    Shenderovich, Julia; Feldman, Mark; Kirmayer, David; Al-Quntar, Abed; Steinberg, Doron; Lavy, Eran; Friedman, Michael

    2015-05-15

    Thiazolidinedione-8 (TZD-8) is an anti-quorum-sensing molecule that has the potential to effectively prevent catheter-associated urinary tract infections, a major healthcare challenge. Sustained-release drug-delivery systems can enhance drugs' therapeutic potential, by maintaining their therapeutic level and reducing their side effects. Varnishes for sustained release of TZD-8 based on ethylcellulose or ammonio methacrylate copolymer type A (Eudragit(®) RL) were developed. The main factors affecting release rate were found to be film thickness and presence of a hydrophilic or swellable polymer in the matrix. The release mechanism of ethylcellulose-based systems matched the Higuchi model. Selected varnishes were retained on catheters for at least 8 days. Sustained-release delivery systems of TZD-8 were active against Candida albicans biofilms. The present study demonstrates promising results en route to developing applications for the prevention of catheter-associated infections. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Challenges and limitations of testing efficacy of aerosol device delivery in young children.

    Science.gov (United States)

    Goralski, Jennifer L; Davis, Stephanie D

    2014-08-01

    An increasing number of medical conditions are chronically or acutely managed with some form of aerosolized therapy. Due to the benefit of directly administering medications to the intended site of action, there is great interest in evaluating treatments for aerosol use. One of the major challenges in selecting and testing new drug-device combinations in children is the uncertainty regarding the appropriate outcome measure to choose. In studies involving adult patients, typically exacerbations of disease or airflow obstruction are assessed as endpoints in drug trials or device assessment. However, in young children, choosing endpoints to assess efficacy is difficult due to the potential lack of sensitive, noninvasive endpoints that are easily performed across sites. In this review, we discuss the challenges and limitations of selecting clinical endpoints for drug-device trials in the youngest population, with a focus on novel emerging technologies. This article provides an overview of preschool and infant pulmonary function testing, multiple-breath washout, imaging techniques including computed tomography and magnetic resonance imaging, flexible bronchoscopy in children, mucociliary clearance scans, and exhaled breath condensate.

  19. Short review on face rejuvenation procedures: focus on preoperative antiseptic and anesthetic delivery by JetPeel™-3 (a high pressure oxygen delivery device).

    Science.gov (United States)

    Iannitti, T; Capone, S; Palmieri, B

    2011-06-01

    Nowadays there is great attention in trying to slow and reverse the facial aging process. Esthetic medicine has been primarily based on the surgical approach for many years, but now, in order to solve the problem of aging skin, there is an increasing interest into non-invasive, possibly painless, procedures that can guarantee the patient a quick recovery. In this perspective the use of chemical peeling and dermabrasion, to achieve skin rejuvenation, is growing worldwide. These techniques are also relevant to treat skin pigmentation irregularities and to remove keratoses, lentigines, acne and other skin related conditions. One of the most interesting, safe and painless devices, useful for the effective antiaging face treatment, is JetPeel™-3. The aim of this study was to assess the device efficacy starting from a short review on face rejuvenation procedures. The basic action mechanism of this medical device is a constant high pressure air flux delivery, including oxygen, mixed with different chemical compounds such as peeling molecules, antioxidants, vitamins and hyaluronic acid, which are mechanically forced across the skin surface. Here we report a new approach in the clinical use of JetPeel™-3, tested in 20 adult volunteers, consisting in the addition to the standard protocol of an anesthetic, carbocaine and a sterilizing and disinfectant agent, that is chlorexidine. In fact disinfection and sterilization of the skin surface is a peculiar step for every antiaging or therapeutic procedure. The procedure has been completed with multiple hyaluronic acid injections of the skin in order to achieve face rejuvenation. The anesthetic power of the JetPeel™-3-carbocaine protocol has been compared to the Emla cream one. The spontaneous pain sensation perceived by the patients in the hemiface treated with JetPeel™-3 was significantly lower compared to the hemiface treated with Emla cream (P<0.001) showing, consequently, that JetPeel™-3-carbocaine protocol had the

  20. Radiation crosslinked polymerization of methacrylamide and psyllium to develop antibiotic drug delivery device.

    Science.gov (United States)

    Singh, Baljit; Sharma, Vikrant; Kumar, Anil; Kumar, Sanjay

    2009-11-01

    Psyllium is a medicinally important polysaccharide and its modification with methacrylamide through radiation crosslinked polymerization will develop hydrogels meant for drug delivery applications. The present paper deals with the preparation of hydrogels and their characterization by SEMs, FTIR, TGA and swelling studies. The release dynamics of model antibiotic drug rifampicin from the hydrogels has been studied for the evaluation of the release mechanism. The values of the diffusion exponent 'n' have been obtained (0.64, 0.58 and 0.57), respectively, in distilled water, pH 2.2 buffer and pH 7.4 buffer. The release of the drug from the hydrogels occurred through non-Fickian diffusion mechanism.

  1. Development of a qualitative exploratory case study research method to explore sustained delivery of cognitive services.

    Science.gov (United States)

    Kaae, Susanne; Søndergaard, Birthe; Haugbølle, Lotte Stig; Traulsen, Janine Morgall

    2010-02-01

    sustainability of cognitive services.

  2. Surface science analysis of GaAs photocathodes following sustained electron beam delivery

    Directory of Open Access Journals (Sweden)

    V. Shutthanandan

    2012-06-01

    Full Text Available Degradation of the photocathode materials employed in photoinjectors represents a challenge for sustained operation of nuclear physics accelerators and high power free electron lasers (FEL. Photocathode quantum efficiency degradation is due to residual gases in the electron source vacuum system being ionized and accelerated back to the photocathode. These investigations are a first attempt to characterize the nature of the photocathode degradation, and employ multiple surface and bulk analysis techniques to investigate damage mechanisms including sputtering of the Cs-oxidant surface monolayer, other surface chemistry effects, and ion implantation. Surface and bulk analysis studies were conducted on two GaAs photocathodes, which were removed from the JLab FEL DC photoemission gun after delivering electron beam, and two control samples. The analysis techniques include helium ion microscopy, Rutherford backscattering spectrometry (RBS, atomic force microscopy, and secondary ion mass spectrometry (SIMS. In addition, two high-polarization strained superlattice GaAs photocathode samples, one removed from the continuous electron beam accelerator facility (CEBAF photoinjector and one unused, were also analyzed using transmission electron microscopy (TEM and SIMS. It was found that heat cleaning the FEL GaAs wafer introduces surface roughness, which seems to be reduced by prolonged use. The bulk GaAs samples retained a fairly well organized crystalline structure after delivering beam but show evidence of Cs depletion on the surface. Within the precision of the SIMS and RBS measurements, the data showed no indication of hydrogen implantation or lattice damage from ion back bombardment in the bulk GaAs wafers. In contrast, SIMS and TEM measurements of the strained superlattice photocathode show clear crystal damage in the wafer from ion back bombardment.

  3. Comparison of the local pulmonary distribution of nanoparticles administered intratracheally to rats via gavage needle or microsprayer delivery devices.

    Science.gov (United States)

    Zhang, Guihua; Shinohara, Naohide; Oshima, Yutaka; Kobayashi, Toshio; Imatanaka, Nobuya; Kawaguchi, Kenji; Gamo, Masashi

    2017-04-01

    Intratracheal administration methods are used to conduct toxicological assessments of inhaled nanoparticles (NPs), and gavage needles or microsprayers are common intratracheal delivery devices. The NP suspension is delivered in a liquid state via gavage needle and as a liquid aerosol via microsprayer. The differences in local pulmonary NP distribution (called the microdistribution) arising from the different states of the NP suspension cause differential pulmonary responses; however, this has yet to be investigated. Herein, using microbeam X-ray fluorescence microscopy, we quantitatively evaluated the TiO2 pulmonary microdistribution (per mesh: 100 μm × 100 μm) in lung sections from rats administered an intratracheal dose of TiO2 NPs (6 mg kg-1 ) via gavage needle or microsprayer. The results revealed that: (i) using a microsprayer appears to reduce the variations in TiO2 content (ng mesh-1 ) among rats (e.g., coefficients of variation, n = 3, microsprayer vs gavage needle: 13% vs 30%, for the entire lungs); (ii) TiO2 appears to be deposited less in the right middle lobes than in the rest of the lung lobes, irrespective of the chosen intratracheal delivery device; and (iii) similar TiO2 contents (ng mesh-1 ) and frequencies are deposited in the lung lobes of rats administered TiO2 NPs via gavage needle or microsprayer. This suggests that the physical state of the administered NP suspension does not markedly alter TiO2 pulmonary microdistribution. The results of this investigation are important for the standardization of intratracheal administration methods. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Sustained prevention of biofilm formation on a novel silicone matrix suitable for medical devices

    DEFF Research Database (Denmark)

    Steffensen, Søren Langer; Merete H., Vestergaard,; Jensen, Minna Grønning

    2015-01-01

    Bacterial colonization and biofilm formation on medical devices constitute major challenges in clinical long-term use of e.g. catheters due to the risk of (re)infection of patients, which would result in additional use of antibiotics risking bacterial resistance development. The aim of the present...... project was to introduce a novel antibacterial approach involving an advanced composite material applicable for medical devices. The polymeric composites investigated consisted of a hydrogel network of cross-linked poly(2-hydroxyethyl methacrylate) (PHEMA) embedded in a poly(dimethylsiloxane) (PDMS....../silicone composite represents a promising candidate material for medical devices that prevent bacterial colonization during long-term use....

  5. Solar Irradiance Measurements Using Smart Devices: A Cost-Effective Technique for Estimation of Solar Irradiance for Sustainable Energy Systems

    Directory of Open Access Journals (Sweden)

    Hussein Al-Taani

    2018-02-01

    Full Text Available Solar irradiance measurement is a key component in estimating solar irradiation, which is necessary and essential to design sustainable energy systems such as photovoltaic (PV systems. The measurement is typically done with sophisticated devices designed for this purpose. In this paper we propose a smartphone-aided setup to estimate the solar irradiance in a certain location. The setup is accessible, easy to use and cost-effective. The method we propose does not have the accuracy of an irradiance meter of high precision but has the advantage of being readily accessible on any smartphone. It could serve as a quick tool to estimate irradiance measurements in the preliminary stages of PV systems design. Furthermore, it could act as a cost-effective educational tool in sustainable energy courses where understanding solar radiation variations is an important aspect.

  6. Electric-Field Guided Precision Manipulation of Catalytic Nanomotors for Cargo Delivery and Powering Nanoelectromechanical Devices.

    Science.gov (United States)

    Guo, Jianhe; Gallegos, Jeremie June; Tom, Ashley Robyn; Fan, Donglei

    2018-01-05

    We report a controllable and precision approach in manipulating catalytic nanomotors by strategically applied electric (E-) fields in three dimensions (3-D). With the high controllability, the catalytic nanomotors have demonstrated versatility in capturing, delivering, and releasing of cargos to designated locations as well as in-situ integration with nanomechanical devices (NEMS) to chemically power the actuation. With combined AC and DC E-fields, catalytic nanomotors can be accurately aligned by the AC E-fields and effectively change their speeds instantly by the DC E-fields. Within the 3-D orthogonal microelectrode sets, the in-plane transport of catalytic nanomotors can be swiftly turned on and off, and these catalytic nanomotors can also move in the vertical direction. The interplaying nanoforces that govern the propulsion and alignment are investigated. The modeling of catalytic nanomotors proposed in previous works has been confirmed quantitatively here. Finally, the prowess of the precision manipulation of catalytic nanomotors by E-fields is demonstrated in two applications: the capture, transport, and release of cargos to pre-patterned microdocks, and the assembly of catalytic nanomotors on NEMS to power the continuous rotation. The concepts and approaches reported in this work could further advance applications of catalytic nanomotors, e.g. for assembling and powering nanomachines, nanorobots, and complex NEMS devices.

  7. Intratumoral chemotherapy with a sustained-release drug delivery system inhibits growth of human pancreatic cancer xenografts.

    Science.gov (United States)

    Smith, J P; Stock, E; Orenberg, E K; Yu, N Y; Kanekal, S; Brown, D M

    1995-12-01

    This study provides the first evidence that treatment of human pancreatic adenocarcinoma is markedly improved by the intratumoral administration of chemotherapeutic agents in a novel drug delivery system. The effect of chemotherapeutic agents delivered in a sustained-release, protein-based, injectable gel was evaluated on the growth of human pancreatic adenocarcinoma cell line, BxPC-3. In vitro chemosensitivity of BxPC-3 cells exposed for 24 or 72 h to fluorouracil (0.01-5 mM), cisplatin or doxorubicin (0.1-50 microM) and floxuridine, vinblastine, mitomycin or paclitaxel (1.0-100 microM) was compared with that of untreated cells. In vitro chemosensitivity was also studied with fluorouracil and mitomycin in the poorly differentiated PANC-1, human pancreatic cancer cell line. Survival was determined after 7-10 days. All drugs decreased cell growth in a dose-dependent fashion. The efficacy of fluorouracil, cisplatin and doxorubicin increased with prolonged exposure, rendering these drugs most appropriate for a sustained-release preparation. For in vivo studies, athymic nude mice bearing BxPC-3 xenografts were treated either with fluorouracil, cisplatin or doxorubicin in the therapeutic injectable gel containing epinephrine or with vehicle alone administered intratumorally on days 1 and 4. After 28 days, the mice were sacrificed and tumors dissected and weighed. Tumors in mice treated with the injectable gel decreased in size by 72-79% compared with tumors in untreated controls and tumors treated with vehicle alone. Intratumoral injection of drug solution and intraperitoneal injection of drug in the injectable gel did not change tumor size compared with controls. In a drug-retention study, mice were injected intratumorally with [3H]fluorouracil either in the injectable gel or in solution. Sustained radioactivity was observed in tumors injected with the gel, and, conversely, greater radioactivity was detected in the liver and kidneys in mice receiving the radiolabeled

  8. Exposure to Electronic Nicotine Delivery Device (ENDS) Visual Imagery Increases Smoking Urge and Desire

    Science.gov (United States)

    King, Andrea C.; Smith, Lia J.; Fridberg, Daniel J.; Matthews, Alicia K.; McNamara, Patrick J.; Cao, Dingcai

    2015-01-01

    Use and awareness of electronic nicotine delivery systems (ENDS; also known as electronic cigarettes or e-cigarettes) has increased rapidly in recent years, particularly among young adults. As use of ENDS resembles traditional smoking in both hand to mouth movements and inhalation and exhalation behaviors, we determined whether exposure to e-cigarette use via video exposure would act as a cue to elicit urge and desire for a combustible cigarette. Young adult smokers (mean age 26.3 ± 4.1 years) were randomized to view a brief video montage of advertisements depicting either e-cigarette vaping (n = 38) or bottled water drinking (n = 40). Pre- and post-cue exposure assessments were conducted in a controlled laboratory setting without other smoking or vaping cues present or behaviors allowed. Primary outcomes included change from pre-exposure baseline in smoking urge (Brief Questionnaire of Smoking Urges) and desire for a combustible and e-cigarette (visual analogue scales). Results showed that relative to exposure to the bottled water video, exposure to the ENDS video significantly increased smoking urge (p behavior. PMID:26618797

  9. The role of community pharmacies in counseling of personal medical devices and drug-delivery products in Estonia.

    Science.gov (United States)

    Volmer, Daisy; Ratassepp, Tagne; Shagandina, Alina; Turunen, Juha; Ahonen, Riitta; Heinämäki, Jyrki

    2015-07-01

    To evaluate the current situation on medical technology at community pharmacies in Estonia, looking into the availability, dispensing and counseling of personal medical devices/drug-delivery products (PMDs/DDPs) and related professional knowledge of community pharmacists. A descriptive cross-sectional questionnaire-based study using an internet-based eFormular study platform. In total, 137 community pharmacies responded to the study. Of the pharmacies, 51.8% dispensed and 32.1% counseled PMDs/DDPs several times a day. 55.4% of the respondents assessed their professional knowledge on PMDs/DDPs as good to medium and 44.6% as satisfactory to poor. Of the respondents, 79.6% reported a need for systematic education about named devices. Community pharmacies are a frequent source for the dispensing and counseling of PMDs/DDPs in Estonia. However, community pharmacists admitted a strong need for continuing education about general and practical aspects related to the use of PMDs/DDPs for the provision of more professional services in the future.

  10. Injectable Polysaccharide Hydrogels as Biocompatible Platforms for Localized and Sustained Delivery of Antibiotics for Preventing Local Infections.

    Science.gov (United States)

    Li, Ziyi; He, Chaoliang; Yuan, Baoming; Dong, Xiaoming; Chen, Xuesi

    2017-04-01

    Biocompatible and antibacterial hydrogels have received increasing attention for preventing local bacterial infections. In this study, a type of polysaccharide hydrogels is prepared via the Schiff-based reaction at physiological conditions. The gelation time and mechanical property of the hydrogels are found to be dependent on the polysaccharide concentration and the polysaccharide weight ratio. 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and live/dead assay indicate that the hydrogels display nontoxicity in vitro. After subcutaneous injection into rats, the hydrogels exhibit an acceptable biocompatibility in vivo. Furthermore, the bacterial inhibition tests by shaking flask method and agar disc-diffusion method demonstrate that the ceftriaxone-sodium-loaded hydrogels have remarkable antibacterial properties in vitro. The in vivo anti-infective tests further display that the antibiotic-loaded hydrogels display excellent anti-infective efficacies in both superficial and deep tissue infection. Consequently, the injectable and biocompatible polysaccharide hydrogels may serve as promising platforms for localized, sustained delivery of antibiotics for preventing local infections. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Synthetic geopolymers for controlled delivery of oxycodone: adjustable and nanostructured porosity enables tunable and sustained drug release.

    Science.gov (United States)

    Forsgren, Johan; Pedersen, Christian; Strømme, Maria; Engqvist, Håkan

    2011-03-15

    In this article we for the first time present a fully synthetic mesoporous geopolymer drug carrier for controlled release of opioids. Nanoparticulate precursor powders with different Al/Si-ratios were synthesized by a sol-gel route and used in the preparation of different geopolymers, which could be structurally tailored by adjusting the Al/Si-ratio and the curing temperatures. In particular, it was shown that the pore sizes of the geopolymers decreased with increasing Al/Si ratio and that completely mesoporous geopolymers could be produced from precursor particles with the Al/Si ratio 2:1. The mesoporosity was shown to be associated with a sustained and linear in vitro release profile of the opioid oxycodone. A clinically relevant release period of about 12 h was obtained by adjusting the size of the pellets. The easily fabricated and tunable geopolymers presented in this study constitute a novel approach in the development of controlled release formulations, not only for opioids, but whenever the clinical indication is best treated with a constant supply of drugs and when the mechanical stability of the delivery vehicle is crucial.

  12. Gelucire Based In Situ Gelling Emulsions: A Potential Carrier for Sustained Stomach Specific Delivery of Gastric Irritant Drugs

    Directory of Open Access Journals (Sweden)

    Ashwin Saxena

    2013-01-01

    Full Text Available Non steroidal anti-inflammatory drugs (NSAIDs are commonly prescribed medications to the geriatric patients for the treatment of arthritis and other painful disorders. The major side effects of NSAIDs are related to their effects on the stomach and bowels. The present study concerns assessment of the potential of liquid in situ gelling emulsion formulations (emulgels as patient compliant stomach specific sustained release carrier for the delivery of highly gastric irritant drug, Piroxicam. Emulgels were prepared, without using any emulgent, by mixing different concentrations of molten Gelucire 39/01 with low viscosity sodium alginate solution prepared in deionized water at 50°C. CaCO3 was used as buoyancy imparting as well as crosslinking agent. Emulgels so prepared were homogenous, physically stable, and rapidly formed into buoyant gelled mass when exposed to simulated gastric fluid (SGF, pH 1.2. Drug release studies carried out in SGF revealed significant retardation (P<0.05 of Piroxicam release from emulgels compared to conventional in situ gelling formulations prepared without Gelucire 39/01. Pharmacodynamic studies carried out in albino rats revealed significantly increased analgesic/anti-inflammatory response from in situ emulgels compared to conventional in situ gelling formulations. Further, in vivo toxicity studies carried out in albino rats revealed no signs of gastric ulceration upon prolonged dosing.

  13. Synthetic Geopolymers for Controlled Delivery of Oxycodone: Adjustable and Nanostructured Porosity Enables Tunable and Sustained Drug Release

    Science.gov (United States)

    Forsgren, Johan; Pedersen, Christian; Strømme, Maria; Engqvist, Håkan

    2011-01-01

    In this article we for the first time present a fully synthetic mesoporous geopolymer drug carrier for controlled release of opioids. Nanoparticulate precursor powders with different Al/Si-ratios were synthesized by a sol-gel route and used in the preparation of different geopolymers, which could be structurally tailored by adjusting the Al/Si-ratio and the curing temperatures. In particular, it was shown that the pore sizes of the geopolymers decreased with increasing Al/Si ratio and that completely mesoporous geopolymers could be produced from precursor particles with the Al/Si ratio 2∶1. The mesoporosity was shown to be associated with a sustained and linear in vitro release profile of the opioid oxycodone. A clinically relevant release period of about 12 h was obtained by adjusting the size of the pellets. The easily fabricated and tunable geopolymers presented in this study constitute a novel approach in the development of controlled release formulations, not only for opioids, but whenever the clinical indication is best treated with a constant supply of drugs and when the mechanical stability of the delivery vehicle is crucial. PMID:21423616

  14. Synthetic geopolymers for controlled delivery of oxycodone: adjustable and nanostructured porosity enables tunable and sustained drug release.

    Directory of Open Access Journals (Sweden)

    Johan Forsgren

    Full Text Available In this article we for the first time present a fully synthetic mesoporous geopolymer drug carrier for controlled release of opioids. Nanoparticulate precursor powders with different Al/Si-ratios were synthesized by a sol-gel route and used in the preparation of different geopolymers, which could be structurally tailored by adjusting the Al/Si-ratio and the curing temperatures. In particular, it was shown that the pore sizes of the geopolymers decreased with increasing Al/Si ratio and that completely mesoporous geopolymers could be produced from precursor particles with the Al/Si ratio 2:1. The mesoporosity was shown to be associated with a sustained and linear in vitro release profile of the opioid oxycodone. A clinically relevant release period of about 12 h was obtained by adjusting the size of the pellets. The easily fabricated and tunable geopolymers presented in this study constitute a novel approach in the development of controlled release formulations, not only for opioids, but whenever the clinical indication is best treated with a constant supply of drugs and when the mechanical stability of the delivery vehicle is crucial.

  15. Three-Dimensional Printed PCL-Based Implantable Prototypes of Medical Devices for Controlled Drug Delivery

    DEFF Research Database (Denmark)

    Hollander, Jenny; Genina, Natalja; Jukarainen, Harri

    2016-01-01

    The goal of the present study was to fabricate drug-containing T-shaped prototypes of intrauterine system (IUS) with the drug incorporated within the entire backbone of the medical device using 3-dimensional (3D) printing technique, based on fused deposition modeling (FDM™). Indomethacin was used...... as a model drug to prepare drug-loaded poly(ε-caprolactone)–based filaments with 3 different drug contents, namely 5%, 15%, and 30%, by hot-melt extrusion. The filaments were further used to 3D print IUS. The results showed that the morphology and drug solid-state properties of the filaments and 3D...... the products. Diffusion of the drug from the polymer was the predominant mechanism of drug release, whereas poly(ε-caprolactone) biodegradation had a minor effect. This study shows that 3D printing is an applicable method in the production of drug-containing IUS and can open new ways in the fabrication...

  16. Fractional Ablative Laser Followed by Transdermal Acoustic Pressure Wave Device to Enhance the Drug Delivery of Aminolevulinic Acid: In Vivo Fluorescence Microscopy Study.

    Science.gov (United States)

    Waibel, Jill S; Rudnick, Ashley; Nousari, Carlos; Bhanusali, Dhaval G

    2016-01-01

    Topical drug delivery is the foundation of all dermatological therapy. Laser-assisted drug delivery (LAD) using fractional ablative laser is an evolving modality that may allow for a greater precise depth of penetration by existing topical medications, as well as more efficient transcutaneous delivery of large drug molecules. Additional studies need to be performed using energy-driven methods that may enhance drug delivery in a synergistic manner. Processes such as iontophoresis, electroporation, sonophoresis, and the use of photomechanical waves aid in penetration. This study evaluated in vivo if there is increased efficacy of fractional CO2 ablative laser with immediate acoustic pressure wave device. Five patients were treated and biopsied at 4 treatment sites: 1) topically applied aminolevulinic acid (ALA) alone; 2) fractional ablative CO2 laser and topical ALA alone; 3) fractional ablative CO2 laser and transdermal acoustic pressure wave device delivery system; and 4) topical ALA with transdermal delivery system. The comparison of the difference in the magnitude of diffusion with both lateral spread of ALA and depth diffusion of ALA was measured by fluorescence microscopy. For fractional ablative CO2 laser, ALA, and transdermal acoustic pressure wave device, the protoporphyrin IX lateral fluorescence was 0.024 mm on average vs 0.0084 mm for fractional ablative CO2 laser and ALA alone. The diffusion for the acoustic pressure wave device was an order of magnitude greater. We found that our combined approach of fractional ablative CO2 laser paired with the transdermal acoustic pressure wave device increased the depth of penetration of ALA.

  17. Magnetically-actuated drug delivery device (MADDD) for minimally invasive treatment of prostate cancer: An in vivo animal pilot study.

    Science.gov (United States)

    Struss, Werner J; Tan, Zheng; Zachkani, Payam; Moskalev, Igor; Jackson, John K; Shademani, Ali; D'Costa, Ninadh M; Raven, Peter A; Frees, Sebastian; Chavez-Munoz, Claudia; Chiao, Mu; So, Alan I

    2017-05-01

    The vast majority of prostate cancer presents clinically localized to the prostate without evidence of metastasis. Currently, there are several modalities available to treat this particular disease. Despite radical prostatectomy demonstrating a modest prostate cancer specific mortality benefit in the PIVOT trial, several novel modalities have emerged to treat localized prostate cancer in patients that are either not eligible for surgery or that prefer an alternative approach. Athymic nude mice were subcutaneously inoculated with prostate cancer cells. The mice were divided into four cohorts, one cohort untreated, two cohorts received docetaxel (10 mg/kg) either subcutaneously (SC) or intravenously (IV) and the fourth cohort was treated using the magnetically-actuated docetaxel delivery device (MADDD), dispensing 1.5 μg of docetaxel per 30 min treatment session. Treatment in all three therapeutic arms (SC, IV, and MADDD) was administered once weekly for 6 weeks. Treatment efficacy was measured once a week according to tumor volume using ultrasound. In addition, calipers were used to assess tumor volume. Animals implanted with the device demonstrated no signs of distress or discomfort, neither local nor systemic symptoms of inflammation and infection. Using an independent sample t-test, the tumor growth rate of the treated tumors was significant when compared to the control. Post hoc Tukey HSD test results showed that the mean tumor growth rate of our device cohort was significantly lower than SC and control cohorts. Moreover, IV cohort showed slight reduction in mean tumor growth rates than the ones from the device cohort, however, there was no statistical significance in tumor growth rate between these two cohorts. Furthermore, immunohistochemistry demonstrated an increased cellular apoptosis in the MADDD treated tumors and a decreased proliferation when compared to the other cohorts. In addition, IV cohort showed increased treatment side effects (weight

  18. "Green" electronics: biodegradable and biocompatible materials and devices for sustainable future.

    Science.gov (United States)

    Irimia-Vladu, Mihai

    2014-01-21

    "Green" electronics represents not only a novel scientific term but also an emerging area of research aimed at identifying compounds of natural origin and establishing economically efficient routes for the production of synthetic materials that have applicability in environmentally safe (biodegradable) and/or biocompatible devices. The ultimate goal of this research is to create paths for the production of human- and environmentally friendly electronics in general and the integration of such electronic circuits with living tissue in particular. Researching into the emerging class of "green" electronics may help fulfill not only the original promise of organic electronics that is to deliver low-cost and energy efficient materials and devices but also achieve unimaginable functionalities for electronics, for example benign integration into life and environment. This Review will highlight recent research advancements in this emerging group of materials and their integration in unconventional organic electronic devices.

  19. E-cigarettes and smoking cessation. Similar efficacy to other nicotine delivery devices, but many uncertainties.

    Science.gov (United States)

    2015-11-01

    E-cigarettes, marketed as an alternative to conventional cigarettes, are designed to transform a solution of variable composition, with or without nicotine, into an aerosol that the user inhales. How effective are e-cigarettes as an aid to smoking cessation, and what are their known adverse effects? To answer these questions, we conducted a review of the literature using the standard Prescrire methodology. A randomised trial involving 657 individuals who wanted to stop smoking compared e-cigarettes (with or without nicotine) with nicotine patches. There was no difference between the groups after 6 months, with an overall quit rate of about 5%. A double-blind randomised trial including 300 smokers compared the impact of e-cigarettes with or without nicotine on tobacco consumption. After 3 months, 14% of those using e-cigarettes with nicotine had quit completely, compared to 4% of those using e-cigarettes without nicotine. Adverse events reported in these trials were mild and transient, and mainly included dry mouth, irritation of the mouth and throat, dizziness, and nausea. When the solution ("e-liquid") contains nicotine, the main adverse effects are those of nicotine. Bronchial disorders, neuropsychiatric disorders and ocular irritation have been reported with inhaled propylene glycol. The effects of propylene glycol and glycerol, when heated and inhaled over long periods, are not known. The addictive effect is difficult to determine. Long-term use of e-cigarettes has been observed in about one-third of people who stopped smoking. Toxic or carcinogenic substances have been found in some e-cigarette aerosols, but at lower concentrations than in tobacco smoke. The diversity in the composition of e-liquids and the lack of proper controls make it difficult to assess the associated dangers. In early 2015, e-cigarettes containing nicotine appear to have efficacy similar to that of other nicotine delivery systems as an aid to smoking cessation. Apart from the effects of

  20. Programmed delivery of verapamil hydrochloride from tablet in a capsule device

    Directory of Open Access Journals (Sweden)

    Mukesh Lal Sah

    2012-06-01

    Full Text Available The aim of the present work was to develop a programmed drug delivery system which would be able to release the drug after 6 h of lag time by use of hydrophilic polymers. The capsule body was made impermeable by use of formaldehyde vapor treatment, while the cap was untreated. The capsule was filled with two layered tablets (tablet-in-capsule, followed by a sodium bicarbonate:citric acid mixture (SBCM and lactose as bulking agent. Sodium alginate, chitosan, HPMC K15 and chitosan:sodium alginate complex (CSAC were used as the rate modulating layer. Through combined use of HPMC K15 and adjusting the ratio of CSAC, the desired lag time of 6 h was obtained. The effect of the bulking agents on the lag time were also studied and it was found that the lag time was decreased with higher amounts of lactose, and delayed dissolution and decreased lag time was observed at higher amount of effervescent mixture.O objetivo do presente trabalho foi desenvolver sistema de liberação programada de cloridrato de verapamil capaz de liberação imediata do fármaco após 6 h de intervalo de tempo usando polímeros hidrofílicos. O corpo da cápsula foi impermeabilizado por tratamento de vapor de formaldeído, enquanto a tampa não foi submetida ao tratamento. Dois comprimidos foram inseridos na cápsula (comprimidos em cápsula seguido de mistura de bicarbonato de sódio: ácido cítrico e lactose, utilizados como excipientes. O alginato de sódio, a quitosana, o HPMC K15 e o complexo quitosana:alginato de sódio foram utilizados para modular a razão de liberação do fármaco. A combinação entre o HPMC K15 e o ajuste da proporção do complexo quitosana:alginato de sódio permitiu a liberação do fármaco após 6 h. O efeito dos excipientes na liberação do fármaco foi também avaliado. Verificou-se que o tempo de latência foi reduzido na presença de maior quantidade de lactose, enquanto o menor tempo foi observado empregando maior concentração da

  1. Poly(glycerol adipate-co-ω-pentadecalactone) spray-dried microparticles as sustained release carriers for pulmonary delivery.

    Science.gov (United States)

    Tawfeek, Hesham; Khidr, Sayed; Samy, Eman; Ahmed, Sayed; Murphy, Mark; Mohammed, Afzaal; Shabir, Anjum; Hutcheon, Gillian; Saleem, Imran

    2011-09-01

    The aim of this work was to optimize biodegradable polyester poly(glycerol adipate-co-ω-pentadecalactone), PGA-co-PDL, microparticles as sustained release (SR) carriers for pulmonary drug delivery. Microparticles were produced by spray drying directly from double emulsion with and without dispersibility enhancers ((L)-arginine and (L)-leucine) (0.5-1.5%w/w) using sodium fluorescein (SF) as a model hydrophilic drug. Spray-dried microparticles without dispersibility enhancers exhibited aggregated powders leading to low fine particle fraction (%FPF) (28.79 ± 3.24), fine particle dose (FPD) (14.42 ± 1.57 μg), with a mass median aerodynamic diameter (MMAD) 2.86 ± 0.24 μm. However, (L)-leucine was significantly superior in enhancing the aerosolization performance ((L-)arginine:%FPF 27.61 ± 4.49-26.57 ± 1.85; FPD 12.40 ± 0.99-19.54 ± 0.16 μg and MMAD 2.18 ± 0.35-2.98 ± 0.25 μm, (L)-leucine:%FPF 36.90 ± 3.6-43.38 ± 5.6; FPD 18.66 ± 2.90-21.58 ± 2.46 μg and MMAD 2.55 ± 0.03-3.68 ± 0.12 μm). Incorporating (L)-leucine (1.5%w/w) reduced the burst release (24.04 ± 3.87%) of SF compared to unmodified formulations (41.87 ± 2.46%), with both undergoing a square root of time (Higuchi's pattern) dependent release. Comparing the toxicity profiles of PGA-co-PDL with (L)-leucine (1.5%w/w) (5 mg/ml) and poly(lactide-co-glycolide), (5 mg/ml) spray-dried microparticles in human bronchial epithelial 16HBE14o- cell lines, resulted in cell viability of 85.57 ± 5.44 and 60.66 ± 6.75%, respectively, after 72 h treatment. The above data suggest that PGA-co-PDL may be a useful polymer for preparing SR microparticle carriers, together with dispersibility enhancers, for pulmonary delivery.

  2. Workshop report: Nucleic acid delivery devices for HIV vaccines: Workshop proceedings, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA, May 21, 2015.

    Science.gov (United States)

    Weniger, Bruce G; Anglin, Ian E; Tong, Tina; Pensiero, Michael; Pullen, Jeffrey K

    2018-01-25

    On May 21st, 2015, the U.S. National Institute of Allergy and Infectious Diseases (NIAID) convened a workshop on delivery devices for nucleic acid (NA) as vaccines in order to review the landscape of past and future technologies for administering NA (e.g., DNA, RNA, etc.) as antigen into target tissues of animal models and humans. Its focus was on current and future applications for preventing and treating human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) disease, among other infectious-disease priorities. Meeting participants presented the results and experience of representative clinical trials of NA vaccines using a variety of alternative delivery devices, as well as a broader group of methods studied in animal models and at bench top, to improve upon the performance and/or avoid the drawbacks of conventional needle-syringe (N-S) delivery. The subjects described and discussed included (1) delivery targeted into oral, cutaneous/intradermal, nasal, upper and lower respiratory, and intramuscular tissues; (2) devices and techniques for jet injection, solid, hollow, and dissolving microneedles, patches for topical passive diffusion or iontophoresis, electroporation, thermal microporation, nasal sprayers, aerosol upper-respiratory and pulmonary inhalation, stratum-corneum ablation by ultrasound, chemicals, and mechanical abrasion, and kinetic/ballistic delivery; (3) antigens, adjuvants, and carriers such as DNA, messenger RNA, synthesized plasmids, chemokines, wet and dry aerosols, and pollen-grain and microparticle vectors; and (4) the clinical experience and humoral, cellular, and cytokine immune responses observed for many of these target tissues, technologies, constructs, and carriers. This report summarizes the presentations and discussions from the workshop (https://web.archive.org/web/20160228112310/https://www.blsmeetings.net/NucleicAcidDeliveryDevices/), which was webcast live in its entirety and archived online (http

  3. Maintaining persistence and adherence with subcutaneous growth-hormone therapy in children: comparing jet-delivery and needle-based devices

    Directory of Open Access Journals (Sweden)

    Spoudeas HA

    2014-09-01

    Full Text Available Helen A Spoudeas,1 Priti Bajaj,2 Nathan Sommerford3 1London Centre for Paediatric Endocrinology, University College London, London, 2Ferring Pharmaceuticals, London, 3Health Informatics Research, Sciensus Ltd, Brighton, UK Purpose: Persistence and adherence with subcutaneous growth hormone (GH; somatropin therapy in children is widely acknowledged to be suboptimal. This study aimed to investigate how the use of a jet-delivery device, ZomaJet®, impacts on medication-taking behaviors compared to needle-based devices.Materials and methods: A retrospective cohort study of children aged ≤18 years was conducted using a UK-based, nationwide database of GH home-delivery schedules. Data were evaluated for the period between January 2010 and December 2012 for 6,061 children receiving either Zomacton® (somatropin via the ZomaJet jet-delivery device or one of six brands of GH all administered via needle-based devices. Persistence was analyzed for patients with appropriate data, measured as the time interval between first and last home deliveries. An analysis of adherence was conducted only for patients using ZomaJet who had appropriate data, measured by proportion of days covered. Brand switches were identified for all patients.Results: Persistence with GH therapy was significantly longer in patients using ZomaJet compared to needle-based devices (599 days versus 535 days, respectively, n=4,093; P<0.001; this association was observed in both sexes and across age subgroups (≤10 and 11–16 years. The majority (58% of patients using ZomaJet were classed as adherent (n=728. Only 297 patients (5% switched GH brand (n=6,061, and patients tended to use ZomaJet for longer than other devices before switching.Conclusion: It appears important that the choice of a jet-delivery device is offered to children prescribed daily GH therapy. These devices may represent a much-needed effective strategy for maintaining persistence with subcutaneous GH administration in

  4. Multilayer encapsulated mesoporous silica nanospheres as an oral sustained drug delivery system for the poorly water-soluble drug felodipine

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Liang [Department of Pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 32, Liaoning Province, Shenyang 110016 (China); Sun, Hongrui [English Teaching Department, School of Basic Courses, Shenyang Pharmaceutical University, Wenhua Road 103, Shenyang 110016 (China); Zhao, Qinfu; Han, Ning; Bai, Ling; Wang, Ying; Jiang, Tongying [Department of Pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 32, Liaoning Province, Shenyang 110016 (China); Wang, Siling, E-mail: silingwang@syphu.edu.cn [Department of Pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 32, Liaoning Province, Shenyang 110016 (China)

    2015-02-01

    We used a combination of mesoporous silica nanospheres (MSN) and layer-by-layer (LBL) self-assembly technology to establish a new oral sustained drug delivery system for the poorly water-soluble drug felodipine. Firstly, the model drug was loaded into MSN, and then the loaded MSN were repeatedly encapsulated by chitosan (CHI) and acacia (ACA) via LBL self-assembly method. The structural features of the samples were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption. The encapsulating process was monitored by zeta-potential and surface tension measurements. The physical state of the drug in the samples was characterized by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). The influence of the multilayer with different number of layers on the drug release rate was studied using thermal gravimetric analysis (TGA) and surface tension measurement. The swelling effect and the structure changes of the multilayer were investigated to explore the relationship between the drug release behavior and the state of the multilayer under different pH conditions. The stability and mucosa adhesive ability of the prepared nanoparticles were also explored. After multilayer coating, the drug release rate was effectively controlled. The differences in drug release behavior under different pH conditions could be attributed to the different states of the multilayer. And the nanoparticles possessed good stability and strong mucosa adhesive ability. We believe that this combination offers a simple strategy for regulating the release rate of poorly water-soluble drugs and extends the pharmaceutical applications of inorganic materials and polymers. - Highlights: • A combination of inorganic and organic materials was applied. • Mesoporous silica nanospheres (MSN) were used as drug carriers. • Chitosan and acacia were encapsulated through layer-by-layer self-assembly. • The release rate of the poorly

  5. Sustained delivery of chondroitinase ABC by poly(propylene carbonate)-chitosan micron fibers promotes axon regeneration and functional recovery after spinal cord hemisection.

    Science.gov (United States)

    Ni, Shilei; Xia, Tongliang; Li, Xingang; Zhu, Xiaodong; Qi, Hongxu; Huang, Shanying; Wang, Jiangang

    2015-10-22

    We describe the sustained delivery of chondroitinase ABC (ChABC) in the hemisected spinal cord using polypropylene carbonate (PPC) electrospun fibers with chitosan (CS) microspheres as a vehicle. PPC and ChABC-loaded CS microspheres were mixed with acetonitrile, and micron fibers were generated by electrospinning. ChABC release was assessed in vitro with high-performance liquid chromatography (HPLC) and revealed stabilized and prolonged release. Moreover, the released ChABC showed sustained activity. PPC-CS micron fibers with or without ChABC were then implanted into a hemisected thoracic spinal cord. In the following 4 weeks, we examined functional recovery and performed immunohistochemical analyses. We found that sustained delivery of ChABC promoted axon sprouting and functional recovery and reduced glial scarring; PPC-CS micron fibers without ChABC did not show these effects. The present findings suggest that PPC-CS micron fibers containing ChABC are a feasible option for spinal cord injury treatment. Furthermore, the system described here may be useful for local delivery of other therapeutic agents. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Microencapsulation of Clostridium difficile specific bacteriophages using microfluidic glass capillary devices for colon delivery using pH triggered release.

    Directory of Open Access Journals (Sweden)

    Gurinder K Vinner

    Full Text Available The prevalence of pathogenic bacteria acquiring multidrug antibiotic resistance is a global health threat to mankind. This has motivated a renewed interest in developing alternatives to conventional antibiotics including bacteriophages (viruses as therapeutic agents. The bacterium Clostridium difficile causes colon infection and is particularly difficult to treat with existing antibiotics; phage therapy may offer a viable alternative. The punitive environment within the gastrointestinal tract can inactivate orally delivered phages. C. difficile specific bacteriophage, myovirus CDKM9 was encapsulated in a pH responsive polymer (Eudragit® S100 with and without alginate using a flow focussing glass microcapillary device. Highly monodispersed core-shell microparticles containing phages trapped within the particle core were produced by in situ polymer curing using 4-aminobenzoic acid dissolved in the oil phase. The size of the generated microparticles could be precisely controlled in the range 80 μm to 160 μm through design of the microfluidic device geometry and by varying flow rates of the dispersed and continuous phase. In contrast to free 'naked' phages, those encapsulated within the microparticles could withstand a 3 h exposure to simulated gastric fluid at pH 2 and then underwent a subsequent pH triggered burst release at pH 7. The significance of our research is in demonstrating that C. difficile specific phage can be formulated and encapsulated in highly uniform pH responsive microparticles using a microfluidic system. The microparticles were shown to afford significant protection to the encapsulated phage upon prolonged exposure to an acid solution mimicking the human stomach environment. Phage encapsulation and subsequent release kinetics revealed that the microparticles prepared using Eudragit® S100 formulations possess pH responsive characteristics with phage release triggered in an intestinal pH range suitable for therapeutic

  7. Effect of Aerosol Devices and Administration Techniques on Drug Delivery in a Simulated Spontaneously Breathing Pediatric Tracheostomy Model.

    Science.gov (United States)

    Alhamad, Bshayer R; Fink, James B; Harwood, Robert J; Sheard, Meryl M; Ari, Arzu

    2015-07-01

    This study was conducted to compare the efficiency of jet nebulizers, vibrating mesh nebulizers, and pressurized metered-dose inhalers (pMDI) during assisted and unassisted administration techniques using a simulated spontaneously breathing pediatric model with a tracheostomy tube (TT). An in vitro breathing model consisting of an uncuffed TT (4.5-mm inner diameter) was attached to a collecting filter (Respirgard) connected to a dual-chamber test lung and a ventilator (Hamilton Medical) to simulate breathing parameters of a 2-y-old child (breathing frequency, 25 breaths/min; tidal volume, 150 mL; inspiratory time, 0.8 s; peak inspiratory flow, 20 L/min). Albuterol sulfate was administered using a jet nebulizer (MicroMist, 2.5 mg/3 mL), vibrating mesh nebulizer (Aeroneb Solo, 2.5 mg/3 mL), and pMDI (ProAir HFA, 432 μg). Each device was tested 5 times with an unassisted technique (direct administration of aerosols with simulated spontaneous breathing) and with an assisted technique (using a manual resuscitation bag in conjunction with an aerosol device and synchronized with inspiration). Drug collected on the filter was analyzed by spectrophotometry. With the unassisted technique, the pMDI had the highest inhaled mass percent (IM%, 47.15 ± 7.82%), followed by the vibrating mesh nebulizer (19.77 ± 2.99%) and the jet nebulizer (5.88 ± 0.77%, P = .002). IM was greater with the vibrating mesh nebulizer (0.49 ± .07 mg) than with the pMDI (0.20 ± 0.03 mg) and the jet nebulizer (0.15 ± 0.01 mg, P = .007). The trend of lower deposition with the assisted versus unassisted technique was not significant for the jet nebulizer (P = .46), vibrating mesh nebulizer (P = .19), and pMDI (P = .64). In this in vitro pediatric breathing model with a TT, the pMDI delivered the highest IM%, whereas the vibrating mesh nebulizer delivered the highest IM. The jet nebulizer was the least efficient device. Delivery efficiency was similar with unassisted and assisted administration

  8. A novel drug delivery of 5-fluorouracil device based on TiO{sub 2}/ZnS nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mendonça Faria, Henrique Antonio, E-mail: henrique.fisica@ifsc.usp.br [Institute of Physics and Chemistry, Federal University of Itajubá (UNIFEI), Av. BPS, 1303, Pinheirinho, Itajubá, MG, PO Box 50, CEP: 37500-903 (Brazil); Nanomedicine and Nanotoxicology Laboratory, São Carlos Institute of Physics, University of São Paulo. Av. Trabalhador São-carlense, 400, Arnold Schimidt, São Carlos, SP CEP: 13566-590 (Brazil); Alencar de Queiroz, Alvaro Antonio, E-mail: alencar@unifei.edu.br [Institute of Physics and Chemistry, Federal University of Itajubá (UNIFEI), Av. BPS, 1303, Pinheirinho, Itajubá, MG, PO Box 50, CEP: 37500-903 (Brazil)

    2015-11-01

    The structural and electronic properties of titanium oxide nanotubes (TiO{sub 2}) have attracted considerable attention for the development of therapeutic devices and imaging probes for nanomedicine. However, the fluorescence response of TiO{sub 2} has typically been within ultraviolet spectrum. In this study, the surface modification of TiO{sub 2} nanotubes with ZnS quantum dots was found to produce a red shift in the ultra violet emission band. The TiO{sub 2} nanotubes used in this work were obtained by sol–gel template synthesis. The ZnS quantum dots were deposited onto TiO{sub 2} nanotube surface by a micelle-template inducing reaction. The structure and morphology of the resulting hybrid TiO{sub 2}/ZnS nanotubes were investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. According to the results of fluorescence spectroscopy, pure TiO{sub 2} nanotubes exhibited a high emission at 380 nm (3.26 eV), whereas TiO{sub 2}/ZnS exhibited an emission at 410 nm (3.02 eV). The TiO{sub 2}/ZnS nanotubes demonstrated good bio-imaging ability on sycamore cultured plant cells. The biocompatibility against mammalian cells (Chinese Hamster Ovarian Cells—CHO) suggesting that TiO{sub 2}/ZnS may also have suitable optical properties for use as biological markers in diagnostic medicine. The drug release characteristic of TiO{sub 2}/ZnS nanotubes was explored using 5-fluorouracil (5-FU), an anticancer drug used in photodynamic therapy. The results show that the TiO{sub 2}/ZnS nanotubes are a promising candidate for anticancer drug delivery systems. - Highlights: • TiO{sub 2}/ZnS nanotubes showed a redshift in fluorescence spectrum. • Cytotoxicity against mammalian cells revealed biocompatibility of the nanotubes. • TiO{sub 2}/ZnS proved an efficient delivery system for anti-tumor 5-fluorouracil.

  9. Harvesting energy an sustainable power source, replace batteries for powering WSN and devices on the IoT

    Science.gov (United States)

    Pop-Vadean, A.; Pop, P. P.; Latinovic, T.; Barz, C.; Lung, C.

    2017-05-01

    Harvesting energy from nonconventional sources in the environment has received increased attention over the past decade from researchers who study these alternative energy sources for low power applications. Although that energy harvested is small and in the order of milliwatt, it can provide enough power for wireless sensors and other low-power applications. In the environment there is a lot of wasted energy that can be converted into electricity to power the various circuits and represents a potentially cheap source of power. Energy harvesting is important because it offers an alternative power supply for electronic devices where is does not exist conventional energy sources. This technology applied in a wireless sensor network (WSN) and devices on the IoT, will eliminate the need for network-based energy and conventional batteries, will minimize maintenance costs, eliminate cables and batteries and is ecological. It has the same advantage in applications from remote locations, underwater, and other hard to reach places where conventional batteries and energy are not suitable. Energy harvesting will promote environmentally friendly technologies that will save energy, will reduce CO2 emissions, which makes this technology indispensable for achieving next-generation smart cities and sustainable society. In response to the challenges of energy, in this article we remind the basics of harvesting energy and we discuss the various applications of this technology where traditional batteries cannot be used.

  10. Microfluidics technology for drug delivery: A review.

    Science.gov (United States)

    Mancera-Andrade, Elena I; Parsaeimehr, Ali; Arevalo-Gallegos, Alejandra; Ascencio-Favela, Guadalupe; Parra Saldivar, Roberto

    2018-01-01

    Microfluidics is undoubtedly an influential technology that is currently revolutionizing the chemical and biological studies by replicating laboratory bench-top technology on a miniature chip-scale device. In the area of drug delivery science, microfluidics offers advantages, such as precise dosage, ideal delivery, target-precise delivery, sustainable and controlled release, multiple dosing, and slight side effects. These advantages bring significant assets to the drug delivery systems. Microfluidic technology has been progressively used for fabrication of drug carriers, direct drug delivery systems, high-throughput screening, and formulation and immobilization of drugs. This review discusses the recent technological progress, outcomes and available opportunities for the usage of microfluidics systems in drug delivery systems.

  11. Preparation of a Sustained-Release Nebulized Aerosol of R-terbutaline Hydrochloride Liposome and Evaluation of Its Anti-asthmatic Effects via Pulmonary Delivery in Guinea Pigs.

    Science.gov (United States)

    Li, Qingrui; Zhan, Shuyao; Liu, Qing; Su, Hao; Dai, Xi; Wang, Hai; Beng, Huimin; Tan, Wen

    2018-01-01

    An aerosolized liposome formulation for the pulmonary delivery of an anti-asthmatic medication was developed. Asthma treatment usually requires frequent administration of medication for a sustained bronchodilator response. Liposomes are known for their sustained drug release capability and thus would be a suitable delivery system for prolonging the therapeutic effect of anti-asthmatic medication. Liposomes prepared by thin film hydration were loaded with a model drug, R-terbutaline hydrochloride(R-TBH), using an ammonium sulfate-induced transmembrane electrochemical gradient. This technique provided an encapsulation efficiency of up to 71.35% and yielded R-TBH liposomes with a particle size of approximately 145 ± 20 nm. According to stability studies, these R-TBH liposomes should be stored at 4°C before usage. Compared to R-TBH solution, which showed 90.84% release within 8 h, liposomal R-TBH had a cumulative release of 73.53% at 37°C over 192 h. A next generation impactor (NGI) was used to analyze the particle size distribution in the lungs of R-TBH liposome aerosol in vitro at 5°C. The therapeutic efficacy of the nebulized aerosol of the R-TBH liposomes was assessed via pulmonary delivery in guinea pigs. The results showed that, compared to the R-TBH solution group, the R-TBH liposome group had a prolonged anti-asthma effect.

  12. Extracellular Matrix (ECM Multilayer Membrane as a Sustained Releasing Growth Factor Delivery System for rhTGF-β3 in Articular Cartilage Repair.

    Directory of Open Access Journals (Sweden)

    Soon Sim Yang

    Full Text Available Recombinant human transforming growth factor beta-3 (rhTGF-β3 is a key regulator of chondrogenesis in stem cells and cartilage formation. We have developed a novel drug delivery system that continuously releases rhTGF-β3 using a multilayered extracellular matrix (ECM membrane. We hypothesize that the sustained release of rhTGF-β3 could activate stem cells and result in enhanced repair of cartilage defects. The properties and efficacy of the ECM multilayer-based delivery system (EMLDS are investigated using rhTGF-β3 as a candidate drug. The bioactivity of the released rhTGF-ß3 was evaluated through chondrogenic differentiation of mesenchymal stem cells (MSCs using western blot and circular dichroism (CD analyses in vitro. The cartilage reparability was evaluated through implanting EMLDS with endogenous and exogenous MSC in both in vivo and ex vivo models, respectively. In the results, the sustained release of rhTGF-ß3 was clearly observed over a prolonged period of time in vitro and the released rhTGF-β3 maintained its structural stability and biological activity. Successful cartilage repair was also demonstrated when rabbit MSCs were treated with rhTGF-β3-loaded EMLDS ((+ rhTGF-β3 EMLDS in an in vivo model and when rabbit chondrocytes and MSCs were treated in ex vivo models. Therefore, the multilayer ECM membrane could be a useful drug delivery system for cartilage repair.

  13. Efficacy of a Novel Prefilled, Single-Use, Needle-Free Device (Zeneo®) in Achieving Intramuscular Agent Delivery: An Observational Study.

    Science.gov (United States)

    Bardou, Marc; Luu, Maxime; Walker, Paul; Auriel, Christophe; Castano, Xavière

    2017-01-01

    It is recognized that, as a result of variation in tissue anatomy, current auto-injectors may have insufficient needle length to achieve successful intramuscular agent delivery in a number of patients. The Zeneo® auto-injector is a novel prefilled, single-use, needle-free device currently in development for intradermal, subcutaneous, and intramuscular agent delivery across a variety of clinical indications. We aimed to evaluate delivery depth of the device calibrated at pressure appropriate for intramuscular (IM) administration. This was a prospective single-center study in healthy adult volunteers, in whom each received a single injection of saline into the anterolateral thigh. Using sequential MRI scans, we measured skin-to-muscle distance (STMD) agent delivery depth, and the success of IM agent penetration. Device dynamic pressure measurements were also recorded. Results are reported for 37 subjects with evaluable MRI scans; 19 men, 18 women; mean age 38 years (range 20-58); mean BMI 27.0 kg/m2 (range 21.2-30.8 kg/m2). Mean STMD values were 18.6 mm (range 13.4-23.6 mm) in women and 10.0 mm (range 5.0-21.7 mm) in men, with gender differences due primarily to greater subcutaneous thickness in women. A trend for greater STMD in subjects with BMI greater than 25 kg/m2 was seen. Mean injectate penetration depths of 30.1 mm (range 20.2-45.6 mm) were observed with values similar in male and female subjects. Successful IM delivery was reported in 95% of subjects. When failure occurred, this was not due to inadequate injection depth. Device pressure (P max) had the greatest influence on injectate muscle penetration. Use of the Zeneo® auto-injector achieves delivery depth that ensures intramuscular delivery in both men and women, regardless of BMI. Consistent with other reported data, STMD is greater in women. Crossject.

  14. Increased Loading, Efficacy and Sustained Release of Silibinin, a Poorly Soluble Drug Using Hydrophobically-Modified Chitosan Nanoparticles for Enhanced Delivery of Anticancer Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Cha Yee Kuen

    2017-11-01

    Full Text Available Conventional delivery of anticancer drugs is less effective due to pharmacological drawbacks such as lack of aqueous solubility and poor cellular accumulation. This study reports the increased drug loading, therapeutic delivery, and cellular accumulation of silibinin (SLB, a poorly water-soluble phenolic compound using a hydrophobically-modified chitosan nanoparticle (pCNP system. In this study, chitosan nanoparticles were hydrophobically-modified to confer a palmitoyl group as confirmed by 2,4,6-Trinitrobenzenesulfonic acid (TNBS assay. Physicochemical features of the nanoparticles were studied using the TNBS assay, and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR analyses. The FTIR profile and electron microscopy correlated the successful formation of pCNP and pCNP-SLB as nano-sized particles, while Dynamic Light Scattering (DLS and Field Emission-Scanning Electron Microscopy (FESEM results exhibited an expansion in size between pCNP and pCNP-SLB to accommodate the drug within its particle core. To evaluate the cytotoxicity of the nanoparticles, a Methylthiazolyldiphenyl-tetrazolium bromide (MTT cytotoxicity assay was subsequently performed using the A549 lung cancer cell line. Cytotoxicity assays exhibited an enhanced efficacy of SLB when delivered by CNP and pCNP. Interestingly, controlled release delivery of SLB was achieved using the pCNP-SLB system, conferring higher cytotoxic effects and lower IC50 values in 72-h treatments compared to CNP-SLB, which was attributed to the hydrophobic modification of the CNP system.

  15. Tailor-Making Fluorescent Hyaluronic Acid Microgels via Combining Microfluidics and Photoclick Chemistry for Sustained and Localized Delivery of Herceptin in Tumors.

    Science.gov (United States)

    Chen, Jing; Huang, Ke; Chen, Qijun; Deng, Chao; Zhang, Jian; Zhong, Zhiyuan

    2018-01-31

    Antibody therapeutics, though representing a most used biomedicine, suffers from poor in vivo stability, rapid degradation, and frequent injections. Here, we report that fluorescent hyaluronic acid microgels (HMGs) tailor-made by combining microfluidics and "tetrazole-alkene" photoclick chemistry enable sustained and localized delivery of Herceptin in ovarian tumors. HMGs were obtained with a defined size (25-50 μm), narrow size distribution, high stability, and strong green fluorescence. Notably, HMGs exhibited a remarkably high loading of proteins such as Herceptin and IgG with a loading efficiency exceeding 90% at a theoretical protein-loading content of 30 wt %. In vitro protein release experiments revealed a sustained and hyaluronidase (HAase)-dependent release of Herceptin from HMGs, in which 80.6% of Herceptin was released at 1 U/mL HAase in 10 days. The released Herceptin maintained its secondary structure and antitumor activity. In vivo imaging results demonstrated obviously better tumoral retention for Cy5-labeled Herceptin-loaded HMGs following subcutaneous (sc) injection than for the free-protein counterpart. Interestingly, sc injection of the Herceptin-loaded HMGs into SKOV-3 human ovarian tumor-bearing nude mice at a dose of 30 mg Herceptin equiv/kg induced nearly complete tumor suppression, which was significantly more effective than the sc or systemic injection of free Herceptin. These tailor-made fluorescent HMGs appeared as a robust injectable platform for sustained and localized delivery of therapeutic proteins.

  16. Percutaneous steerable robotic tool delivery platform and metal microelectromechanical systems device for tissue manipulation and approximation: closure of patent foramen ovale in an animal model.

    Science.gov (United States)

    Vasilyev, Nikolay V; Gosline, Andrew H; Butler, Evan; Lang, Nora; Codd, Patrick J; Yamauchi, Haruo; Feins, Eric N; Folk, Chris R; Cohen, Adam L; Chen, Richard; Zurakowski, David; del Nido, Pedro J; Dupont, Pierre E

    2013-08-01

    Beating-heart image-guided intracardiac interventions have been evolving rapidly. To extend the domain of catheter-based and transcardiac interventions into reconstructive surgery, a new robotic tool delivery platform and a tissue approximation device have been developed. Initial results using these tools to perform patent foramen ovale closure are described. A robotic tool delivery platform comprising superelastic metal tubes provides the capability of delivering and manipulating tools and devices inside the beating heart. A new device technology is also presented that uses a metal-based microelectromechanical systems-manufacturing process to produce fully assembled and fully functional millimeter-scale tools. As a demonstration of both technologies, patent foramen ovale creation and closure was performed in a swine model. In the first group of animals (n=10), a preliminary study was performed. The procedural technique was validated with a transcardiac hand-held delivery platform and epicardial echocardiography, video-assisted cardioscopy, and fluoroscopy. In the second group (n=9), the procedure was performed percutaneously using the robotic tool delivery platform under epicardial echocardiography and fluoroscopy imaging. All patent foramen ovales were completely closed in the first group. In the second group, the patent foramen ovale was not successfully created in 1 animal, and the defects were completely closed in 6 of the 8 remaining animals. In contrast to existing robotic catheter technologies, the robotic tool delivery platform uses a combination of stiffness and active steerability along its length to provide the positioning accuracy and force-application capability necessary for tissue manipulation. In combination with a microelectromechanical systems tool technology, it can enable reconstructive procedures inside the beating heart.

  17. Sheath hemorrhage after percutaneous ventricular assist device implantation.

    Science.gov (United States)

    Siddiqi, Saadi; Ganga, Harsha V; Dhesi, Pavittarpaul; Azemi, Talhat; Chamakura, Sanjayant; Kiernan, Francis J; Hammond, Jonathan A; Sadiq, Immad R

    2014-04-01

    Technical advances in temporary ventricular assist devices (VADs) continue to progress, allowing for percutaneous implantation during times of hemodynamic instability. However, device delivery systems, i.e., sheaths, lag in their ability to sustain the mechanical demands of these VADs for extended periods. We propose both a novel technique and the implementation of an emergency preparedness plan to be enacted specifically during those times when delivery systems fail thereby leading to potentially catastrophic bleeding complications.

  18. Gene silencing in non-model insects: Overcoming hurdles using symbiotic bacteria for trauma-free sustainable delivery of RNA interference: Sustained RNA interference in insects mediated by symbiotic bacteria: Applications as a genetic tool and as a biocide.

    Science.gov (United States)

    Whitten, Miranda; Dyson, Paul

    2017-03-01

    Insight into animal biology and development provided by classical genetic analysis of the model organism Drosophila melanogaster was an incentive to develop advanced genetic tools for this insect. But genetic systems for the over one million other known insect species are largely undeveloped. With increasing information about insect genomes resulting from next generation sequencing, RNA interference is now the method of choice for reverse genetics, although it is constrained by the means of delivery of interfering RNA. A recent advance to ensure sustained delivery with minimal experimental intervention or trauma to the insect is to exploit commensal bacteria for symbiont-mediated RNA interference. This technology not only offers an efficient means for RNA interference in insects in laboratory conditions, but also has potential for use in the control of human disease vectors, agricultural pests and pathogens of beneficial insects. © 2017 WILEY Periodicals, Inc.

  19. Economic and organizational sustainability of a negative-pressure portable device for the prevention of surgical-site complications

    Directory of Open Access Journals (Sweden)

    Foglia E

    2017-06-01

    ,787.92 and an organizational saving in terms of length of stay equal to −1.10% (−898 days, thus allowing 95 additional procedures.Conclusion: The implementation of a portable device for NPWT would represent an effective and sustainable strategy for reducing the management costs of patients. Economic and organizational savings could be reinvested, thus i treating a wider population and ii reducing waiting lists, with a higher effectiveness in terms of a decrease in complications. Keywords: NPWT portable device, budget impact analysis, economic analysis, organizational advantage, Italy

  20. Bogataj in Del Gobbo (ur. (2015. Lifelong learning devices for sustainable local development. Gorizia, Comitato regionale dell‘Enfap del Friuli Venezia Giulia

    Directory of Open Access Journals (Sweden)

    Janko Muršak

    2015-12-01

    Full Text Available V okviru programa čezmejnega sodelovanja, ki ga sofinancira Evropski sklad za regionalni razvoj, je izšla monografija o čezmejnem delovanju študijskih krožkov ob slovensko- -italijanski meji z naslovom Lifelong learning devices for sustainable development ter s podnaslovom The study circles experience in the cross border area Italy-Slovenia.

  1. Research on the comparison of the demethylvancomycin's diffusion-deposition characteristics in the ocular solid tissues of sustained subtenon drug delivery with subconjunctival injection.

    Science.gov (United States)

    Duan, Yi-Qin; Yang, Ye-Zhen; Huang, Xue-Tao; Lin, Ding

    2017-11-01

    To compare the demethylvancomycin's diffusion-deposition characteristics in the ocular solid tissues of sustained subtenon drug delivery with subconjunctival injection. Sixty adult white rabbits were randomly assigned to the subtenon drug delivery group and the subconjunctival injection group. The subtenon drug delivery group was continuously infused demethylvancomycin to the subtenon of rabbits. The subconjunctival injection group was injected demethylvancomycin to the subconjunctival of rabbits. Cornea, iris and sclera were collected for high-performance liquid chromatography analyses to determine drug concentrations at one hour, three hours, six hours, 12 h and 24 h of drug administration. WinNonlin 6.3 was used to calculate the parameters of cumulative area under the curve (AUCcum) of demethylvancomycin. The peak levels of demethylvancomycin concentration of the subtenon drug delivery group and the subconjunctival injection group were 92.406 ± 21.555 and 51.778 ± 14.001 μg/g in cornea, 28.451 ± 10.229 μg/g and 42.271 ± 27.291 μg/g in iris, 153.166 ± 51.738 μg/g and 57.423 ± 18.480 μg/g in sclera. The differences of concentrations between the two groups in cornea and sclera were statistically significant (F = 487.775, p drug delivery group and the subconjunctival injection group was 1808.23 h * μg/g and 273.73 h * μg/g in cornea, 489.12 h * μg/g and 216.16 h * μg/g in iris and 2166.34 h * μg/g and 392.57 h * μg/g in sclera at 24 h of drug administration. The sustained subtenon drug delivery had a better drug permeability and accumulation in the intraocular solid tissue compared to subconjunctival injection, which demonstrated it was probably a promising and effective approach for treating posterior segment diseases and endophthalmitis.

  2. Sustained co-delivery of BIO and IGF-1 by a novel hybrid hydrogel system to stimulate endogenous cardiac repair in myocardial infarcted rat hearts

    Science.gov (United States)

    Fang, Rui; Qiao, Shupei; Liu, Yi; Meng, Qingyuan; Chen, Xiongbiao; Song, Bing; Hou, Xiaolu; Tian, Weiming

    2015-01-01

    Dedifferentiation and proliferation of endogenous cardiomyocytes in situ can effectively improve cardiac repair following myocardial infarction (MI). 6-Bromoindirubin-3-oxime (BIO) and insulin-like growth factor 1 (IGF-1) are two potent factors that promote cardiomyocyte survival and proliferation. However, their delivery for sustained release in MI-affected areas has proved to be challenging. In the current research, we present a study on the sustained co-delivery of BIO and IGF-1 in a hybrid hydrogel system to simulate endogenous cardiac repair in an MI rat model. Both BIO and IGF-1 were efficiently encapsulated in gelatin nanoparticles, which were later cross-linked with the oxidized alginate to form a novel hybrid hydrogel system. The in vivo results indicated that the hybrid system could enhance the proliferation of cardiomyocytes in situ and could promote revascularization around the MI sites, allowing improved cardiac function. Taken together, we concluded that the hybrid hydrogel system can co-deliver BIO and IGF-1 to areas of MI and thus improve cardiac function by promoting the proliferation of cardiomyocytes and revascularization. PMID:26251592

  3. Organic Nanovesicular Cargoes for Sustained Drug Delivery: Synthesis, Vesicle Formation, Controlling “Pearling” States, and Terfenadine Loading/Release Studies

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Botcha

    2014-01-01

    Full Text Available “Sustained drug delivery systems” which are designed to accomplish long-lasting therapeutic effect are one of the challenging topics in the area of nanomedicine. We developed an innovative strategy to prepare nontoxic and polymer stabilized organic nanovesicles (diameter: 200 nm from a novel bolaamphiphile, where two hydrogen bonding acetyl cytosine molecules connected to 4,4′′-positions of the 2,6-bispyrazolylpyridine through two flexible octyne chains. The nanovesicles behave like biological membrane by spontaneously self-assembling into “pearl-like” chains and subsequently forming long nanotubes (diameter: 150 nm, which further develop into various types of network-junctions through self-organization. For drug loading and delivery applications, the nanovesicles were externally protected with biocompatible poly(ethyleneglycol-2000 to prevent them from fusion and ensuing tube formation. Nontoxic nature of the nanovesicles was demonstrated by zebrafish teratogenicity assay. Biocompatible nanovesicles were loaded with “terfenadine” drug and successfully utilized to transport and release drug in sustained manner (up to 72 h in zebrafish larvae, which is recognized as an emerging in vivo model system.

  4. Sustained delivery of rhBMP-2 by means of poly(lactic-co-glycolic acid) microspheres: cranial bone regeneration without heterotopic ossification or craniosynostosis.

    Science.gov (United States)

    Wink, Jason D; Gerety, Patrick A; Sherif, Rami D; Lim, Youngshin; Clarke, Nadya A; Rajapakse, Chamith S; Nah, Hyun-Duck; Taylor, Jesse A

    2014-07-01

    Commercially available recombinant human bone morphogenetic protein 2 (rhBMP2) has demonstrated efficacy in bone regeneration, but not without significant side effects. The authors used rhBMP2 encapsulated in poly(lactic-co-glycolic acid) (PLGA) microspheres placed in a rabbit cranial defect model to test whether low-dose, sustained delivery can effectively induce bone regeneration. The rhBMP2 was encapsulated in 15% PLGA using a double-emulsion, solvent extraction/evaporation technique, and its release kinetics and bioactivity were tested. Two critical-size defects (10 mm) were created in the calvaria of New Zealand white rabbits (5 to 7 months of age, male and female) and filled with a collagen scaffold containing either (1) no implant, (2) collagen scaffold only, (3) PLGA-rhBMP2 (0.1 μg per implant), or (4) free rhBMP2 (0.1 μg per implant). After 6 weeks, the rabbits were killed and defects were analyzed by micro-computed tomography, histology, and finite element analysis. The rhBMP2 delivered by means of bioactive PLGA microspheres resulted in higher volumes and surface area coverage of new bone than an equal dose of free rhBMP2 by micro-computed tomography (p=0.025 and p=0.025). Finite element analysis indicated that the mechanical competence using the regional elastic modulus did not differ with rhBMP2 exposure (p=0.70). PLGA-rhBMP2 did not demonstrate heterotopic ossification, craniosynostosis, or seroma formation. Sustained delivery by means of PLGA microspheres can significantly reduce the rhBMP2 dose required for de novo bone formation. Optimization of the delivery system may be a key to reducing the risk for recently reported rhBMP2-related adverse effects.

  5. Long-lasting fibrin matrices ensure stable and functional angiogenesis by highly tunable, sustained delivery of recombinant VEGF164.

    Science.gov (United States)

    Sacchi, Veronica; Mittermayr, Rainer; Hartinger, Joachim; Martino, Mikaël M; Lorentz, Kristen M; Wolbank, Susanne; Hofmann, Anna; Largo, Remo A; Marschall, Jeffrey S; Groppa, Elena; Gianni-Barrera, Roberto; Ehrbar, Martin; Hubbell, Jeffrey A; Redl, Heinz; Banfi, Andrea

    2014-05-13

    Clinical trials of therapeutic angiogenesis by vascular endothelial growth factor (VEGF) gene delivery failed to show efficacy. Major challenges include the need to precisely control in vivo distribution of growth factor dose and duration of expression. Recombinant VEGF protein delivery could overcome these issues, but rapid in vivo clearance prevents the stabilization of induced angiogenesis. Here, we developed an optimized fibrin platform for controlled delivery of recombinant VEGF, to robustly induce normal, stable, and functional angiogenesis. Murine VEGF164 was fused to a sequence derived from α2-plasmin inhibitor (α2-PI1-8) that is a substrate for the coagulation factor fXIIIa, to allow its covalent cross-linking into fibrin hydrogels and release only by enzymatic cleavage. An α2-PI1-8-fused variant of the fibrinolysis inhibitor aprotinin was used to control the hydrogel degradation rate, which determines both the duration and effective dose of factor release. An optimized aprotinin-α2-PI1-8 concentration ensured ideal degradation over 4 wk. Under these conditions, fibrin-α2-PI1-8-VEGF164 allowed exquisitely dose-dependent angiogenesis: concentrations ≥25 μg/mL caused widespread aberrant vascular structures, but a 500-fold concentration range (0.01-5.0 μg/mL) induced exclusively normal, mature, nonleaky, and perfused capillaries, which were stable after 3 mo. Optimized delivery of fibrin-α2-PI1-8-VEGF164 was therapeutically effective both in ischemic hind limb and wound-healing models, significantly improving angiogenesis, tissue perfusion, and healing rate. In conclusion, this optimized platform ensured (i) controlled and highly tunable delivery of VEGF protein in ischemic tissue and (ii) stable and functional angiogenesis without introducing genetic material and with a limited and controllable duration of treatment. These findings suggest a strategy to improve safety and efficacy of therapeutic angiogenesis.

  6. Modified thermoresponsive Poloxamer 407 and chitosan sol-gels as potential sustained-release vaccine delivery systems

    DEFF Research Database (Denmark)

    Kojarunchitt, Thunjiradasiree; Baldursdottir, Stefania; Dong, Yao-Da

    2015-01-01

    A and monophosphoryl lipid A), were free-flowing liquids at room temperature and formed stable gels at physiological temperatures. Rheological results showed that both systems meet the criteria of being thermoresponsive gels. The P407-25R4 sol-gels did not significantly sustain the release of antigen in vivo while...... the chitosan-MC sol-gels sustained the release of antigen up to at least 14 days after administration. The chitosan-MC sol-gels stimulated both cellular and humoral responses. The inclusion of cubosomes in the sol-gels did not provide a definitive beneficial effect. Further analysis of the formulations...

  7. The Sustained Effects on Tear Volume of Pilocarpine Hydrochloride in Gelatin by Hydrogel Administered by An Implant-mediated Drug Delivery System.

    Science.gov (United States)

    Cha, Seunghee; Kim, Hong-Kyun; Kho, Hong-Seop; Park, Young-Seok

    2017-01-01

    Pilocarpine hydrochloride is commonly prescribed to patients with dry mouth and eye using a frequent dosing schedule. The aim of this study was to evaluate the sustained effects of this highly soluble drug carried by a gelatin hydrogel, which was administered by an implant mediated drug delivery system (IMDDS). The IMDDS was installed in a total of 24 rabbits. After complete healing, pilocarpine hydrochloride was administered as 30 mg as raw powder (Group 1; n = 8), 30 mg in gelatin hydrogel (Group 2; n = 8), and 60 mg in gelatin hydrogel (Group 3; n = 8). The effects were evaluated by tear volume measured using the Schirmer tear test for 2 weeks after administration. All 3 groups showed an increase in tear volume from the initial measurement at 1 hour. Group 1 exhibited this increase for 24 hours, while Groups 2 and 3 sustained this increase for 5 days and 7.5 days, respectively. When provided in gelatin hydrogel, highly water-soluble pilocarpine hydrochloride administered through IMDDS resulted in sustained effects with increased tear volume in normal rabbits. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Long-lasting fibrin matrices ensure stable and functional angiogenesis by highly tunable, sustained delivery of recombinant VEGF164

    OpenAIRE

    Sacchi, Veronica; Mittermayr, Rainer; Hartinger, Joachim; Martino, Mikaël M.; Lorentz, Kristen M.; Wolbank, Susanne; Hofmann, Anna; Largo, Remo A.; Marschall, Jeffrey S.; Groppa, Elena; Gianni-Barrera, Roberto; Ehrbar, Martin; Hubbell, Jeffrey A.; Redl, Heinz; Banfi, Andrea

    2014-01-01

    Inducing the growth of new blood vessels by specific factors is an attractive strategy to restore blood flow in ischemic tissues. Vascular endothelial growth factor (VEGF) is the master regulator of angiogenesis, yet clinical trials of VEGF gene delivery failed. Major challenges include the need to control the tissue distribution of factor dose and the duration of expression. Here, we developed a highly tunable fibrin-based platform to precisely control the dose and duration of VEGF protein d...

  9. People Centered Innovation: Enabling Lean Integrated Project Delivery and Disrupting the Construction Industry for a More Sustainable Future

    Directory of Open Access Journals (Sweden)

    William Paolillo

    2016-01-01

    Full Text Available People-centered innovation is a paradigm shift in the construction industry. It is derived from the supposition that people not methods, schedules, or budgets deliver projects. Our data suggest that a multilevel, multidisciplinary project team through shared vision, values, and a common vernacular defines, designs, and delivers more successful projects than traditional methods. These projects meet the needs of shareholders, the community, stakeholders, and the planet. We employ the concepts of emotional intelligence and agency theory to explain an integrated project delivery (IPD construction project using lean tactics that not only delivered, but also exceeded expectations resulting in a six-month schedule acceleration and $60M savings over the original estimated cost of the project calculated assuming traditional project delivery methods. The safety rating for this project was 50% better than the national average and the expected improvement in operating margin for the new building is 33% greater. This paper introduces the notion of people-centered innovation to an industry that has struggled to adapt and show positive results over recent decades. Our case study describes the significance of people-centered innovation in construction project delivery. We discuss the implications for the construction industry going forward.

  10. Acceptability of a non-woven device for vaginal drug delivery of microbicides or other active agents.

    Science.gov (United States)

    Joanis, Carol L; Hart, Catherine W

    2010-06-01

    Vaginal microbicides could reduce incidence of HIV. However, the current method of delivering gel formulations (standard applicator) can result in acceptability concerns/issues. This study evaluated the concept of using a non-woven textile material (modified tampon) for vaginal drug delivery. The study was nested within a Phase I randomized safety trial of lime juice concentrations used intra-vaginally. Of 47 women completing the safety trial, 16 were interviewed about their experiences. Overall, women found the concept of non-woven materials for vaginal drug delivery acceptable for use in delivering yeast medications (13 of 16) and STI/HIV preventives (10 of 16).

  11. Phytantriol and glyceryl monooleate cubic liquid crystalline phases as sustained-release oral drug delivery systems for poorly water-soluble drugs II. In-vivo evaluation.

    Science.gov (United States)

    Nguyen, Tri-Hung; Hanley, Tracey; Porter, Christopher J H; Larson, Ian; Boyd, Ben J

    2010-07-01

    Lipid-based liquid crystals formed from phytantriol (PHY) and glyceryl monooleate (GMO) retain their cubic-phase structure on dilution in physiologically relevant simulated gastrointestinal media, suggesting their potential application as sustained-release drug-delivery systems for poorly water-soluble drugs. In this study the potential of PHY and GMO to serve as sustained-release lipid vehicles for a model poorly-water-soluble drug, cinnarizine, was assessed and compared to that of an aqueous suspension formulation. Small-angle X-ray scattering was used to confirm the nanostructure of the liquid-crystalline matrix in the presence of the selected model drug, cinnarizine. Oral bioavailability studies were conducted in rats, and disposition of lipid and drug in segments of the gastrointestinal tract was determined over time. Differences in the digestibility and stability of formulations under digestion conditions were investigated using an in-vitro lipolysis model. The oral bioavailability of cinnarizine using the PHY formulation was 41%, compared to 19% for the GMO formulation and 6% for an aqueous suspension. The PHY formulation provided a T(max) for cinnarizine of 33 h, with absorption apparent up to 55 h after administration. In contrast, the T(max) for the GMO formulation was only 5 h. The PHY formulation was retained in the stomach for extended periods of time, with 56% of lipid remaining in the stomach after 24 h, in contrast to less than 1% of the GMO formulation after 8 h, suggesting that gastric retention was a key aspect of the prolonged period of absorption, which correlated with the formulations' relative susceptibility to in-vitro lipolysis and degradation. PHY provides a dramatic sustained-release effect for cinnarizine on oral administration, which is linked to gastric retention of the formulation and its ability to resist digestive processing. Poorly digested liquid crystal lipid formulations therefore offer a novel class of sustained

  12. Novel 'nano in nano' composites for sustained drug delivery: biodegradable nanoparticles encapsulated into nanofiber non-wovens.

    Science.gov (United States)

    Beck-Broichsitter, Moritz; Thieme, Marcel; Nguyen, Juliane; Schmehl, Thomas; Gessler, Tobias; Seeger, Werner; Agarwal, Seema; Greiner, Andreas; Kissel, Thomas

    2010-12-08

    Novel 'nano in nano' composites consisting of biodegradable polymer nanoparticles incorporated into polymer nanofibers may efficiently modulate drug delivery. This is shown here using a combination of model compound-loaded biodegradable nanoparticles encapsulated in electrospun fibers. The dye coumarin 6 is used as model compound for a drug in order to simulate drug release from loaded poly(lactide-co-glycolide) nanoparticles. Dye release from the nanoparticles occurs immediately in aqueous solution. Dye-loaded nanoparticles which are encapsulated by electrospun polymer nanofibers display a significantly retarded release. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Sustained delivery of activated Rho GTPases and BDNF promotes axon growth in CSPG-rich regions following spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Anjana Jain

    2011-01-01

    Full Text Available Spinal cord injury (SCI often results in permanent functional loss. This physical trauma leads to secondary events, such as the deposition of inhibitory chondroitin sulfate proteoglycan (CSPG within astroglial scar tissue at the lesion.We examined whether local delivery of constitutively active (CA Rho GTPases, Cdc42 and Rac1 to the lesion site alleviated CSPG-mediated inhibition of regenerating axons. A dorsal over-hemisection lesion was created in the rat spinal cord and the resulting cavity was conformally filled with an in situ gelling hydrogel combined with lipid microtubes that slowly released constitutively active (CA Cdc42, Rac1, or Brain-derived neurotrophic factor (BDNF. Treatment with BDNF, CA-Cdc42, or CA-Rac1 reduced the number of GFAP-positive astrocytes, as well as CSPG deposition, at the interface of the implanted hydrogel and host tissue. Neurofilament 160kDa positively stained axons traversed the glial scar extensively, entering the hydrogel-filled cavity in the treatments with BDNF and CA-Rho GTPases. The treated animals had a higher percentage of axons from the corticospinal tract that traversed the CSPG-rich regions located proximal to the lesion site.Local delivery of CA-Cdc42, CA-Rac1, and BDNF may have a significant therapeutic role in overcoming CSPG-mediated regenerative failure after SCI.

  14. Technical report Development of a piezoelectric inkjet dopant delivery device for an atmospheric pressure photoionization source with liquid chromatography/mass spectrometry

    KAUST Repository

    Amad, Maan H.

    2013-01-01

    This paper describes a simple robust and integrated piezoelectric actuated printhead as a dopant delivery system for atmospheric pressure photoionization with liquid chromatography/mass spectrometry The newly designed dopant delivery system avoids problems associated with traditional liquid delivery systems such as solvent immiscibility backpressure and increased post-column dead volume issues The performance of the new device was tested and evaluated using chlorobenzene as a dopant with a test mixture consisting of 18 different polycyclic aromatic hydrocarbons (PAHs) The results show that the new system works robustly at low dopant consumption level (16 uL min-1) consuming only approximately 5% of the amount used by conventional sources The low dopant consumption has resulted in up to a 20-fold reduction in signal intensity of tested PAH molecules but has led to less presence of background cluster ions and dopant trace contaminant background ions in the source area Consequently all tested PAHs were detected with excellent signal-to-noise ratio with at least two-to ten-fold improvements in the limit of detection and quantification compared to those obtained with traditional dopant assistance using a post-column addition method © IM Publications LLP 2013.

  15. Sustained Delivery of Bioactive GDNF from Collagen and Alginate-Based Cell-Encapsulating Gel Promoted Photoreceptor Survival in an Inherited Retinal Degeneration Model.

    Directory of Open Access Journals (Sweden)

    Francisca S Y Wong

    Full Text Available Encapsulated-cell therapy (ECT is an attractive approach for continuously delivering freshly synthesized therapeutics to treat sight-threatening posterior eye diseases, circumventing repeated invasive intravitreal injections and improving local drug availability clinically. Composite collagen-alginate (CAC scaffold contains an interpenetrating network that integrates the physical and biological merits of its constituents, including biocompatibility, mild gelling properties and availability. However, CAC ECT properties and performance in the eye are not well-understood. Previously, we reported a cultured 3D CAC system that supported the growth of GDNF-secreting HEK293 cells with sustainable GDNF delivery. Here, the system was further developed into an intravitreally injectable gel with 1x104 or 2x105 cells encapsulated in 2mg/ml type I collagen and 1% alginate. Gels with lower alginate concentration yielded higher initial cell viability but faster spheroid formation while increasing initial cell density encouraged cell growth. Continuous GDNF delivery was detected in culture and in healthy rat eyes for at least 14 days. The gels were well-tolerated with no host tissue attachment and contained living cell colonies. Most importantly, gel-implanted in dystrophic Royal College of Surgeons rat eyes for 28 days retained photoreceptors while those containing higher initial cell number yielded better photoreceptor survival. CAC ECT gels offers flexible system design and is a potential treatment option for posterior eye diseases.

  16. Enabling the sustainable Faecal Sludge Management service delivery chain-A case study of dense settlements in Kigali, Rwanda.

    Science.gov (United States)

    Akumuntu, Jean Baptiste; Wehn, Uta; Mulenga, Martin; Brdjanovic, Damir

    2017-08-01

    The lack of access to basic sanitation is a global concern and alarmingly prevalent in low- and middle- income countries. In the densely populated settlements of these countries, on-site sanitation systems are usually the only feasible option because dwellers there have no sewers in place to connect to. Using on-site sanitation facilities results in an accumulation of faecal sludge which needs to be properly managed to ensure the well-being of the users as well as the surrounding environment. Unfortunately, often the conditions for faecal sludge management (FSM) within dense settlements are adverse and thus hamper sustainable FSM. We use the normative framework of the FSM enabling environment to gather empirical evidence from densely populated settlements of Kigali city in Rwanda to examine current FSM practices and the extent to which these are being influenced and affected by the setting within which they are taking place. The analysis of the study findings confirms that the existing conditions for FSM in these settlements are inadequate. The specific constraints that hinder the achievement of sustainable FSM include limited government focus on the sanitation sector, high turnover of staff in relevant government institutions, pit sludge management is not placed on the sanitation projects agenda, the existing relevant bylaws are not pro-poor oriented, a lack of clear responsibilities, a lack of relevant local professional training opportunities, unaffordability of FSM services and an inhibition to discuss FSM. Drawing on the involved stakeholders' own perceptions and suggestions, we identify possible approaches to overcome the identified constraints and to allow all actors in the FSM chain to contribute effectively to the management of faecal sludge in densely populated low-income urban settlements. Finally, our study also presents a contribution to the theoretical conceptualisation of the enabling environment for sustainable FSM. Copyright © 2017 Elsevier Gmb

  17. Improving sustained drug delivery from ophthalmic lens materials through the control of temperature and time of loading.

    Science.gov (United States)

    Topete, Ana; Oliveira, Andreia S; Fernandes, A; Nunes, T G; Serro, A P; Saramago, B

    2018-02-14

    Although the possibility of using drug-loaded ophthalmic lens to promote sustained drug release has been thoroughly pursued, there are still problems to be solved associated to the different alternatives. In this work, we went back to the traditional method of drug loading by soaking in the drug solution and tried to optimize the release profiles by changing the temperature and the time of loading. Two materials commercially available under the names of CI26Y and Definitive 50 were chosen. CI26Y is used for intraocular lenses (IOLs) and Definitive 50 for soft contact lenses (SCLs). Three drugs were tested: an antibiotic, moxifloxacin, and two anti-inflammatories, diclofenac and ketorolac. Sustained drug release from CI26Y disks for, at least 15 days, was obtained for moxifloxacin and diclofenac increasing the loading temperature up to 60 °C or extending the loading time till two months. The sustained release of ketorolac was limited to about 8 days. In contrast, drug release from Definitive 50 disks could not be improved by changing the loading conditions. An attempt to interpret the impact of the loading conditions on the drug release behavior was done using solid-state NMR and differential scanning calorimetry. These studies suggested the establishment of reversible, endothermic interactions between CI26Y and the drugs, moxifloxacin and diclofenac. The loading temperature had a slight effect on the mechanical and optical properties of drug loaded CI26Y samples, which still kept adequate properties to be used as IOL materials. The in vivo efficacy of CI26Y samples, drug loaded at 60 °C for two weeks, was predicted using a simplified mathematical model to estimate the drug concentration in the aqueous humor. The estimated concentrations were found to comply with the therapeutic needs, at least, for moxifloxacin and diclofenac. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Nicotine delivery from the refill liquid to the aerosol via high-power e-cigarette device.

    Science.gov (United States)

    Prévôt, Nathalie; de Oliveira, Fabien; Perinel-Ragey, Sophie; Basset, Thierry; Vergnon, Jean-Michel; Pourchez, Jérémie

    2017-06-01

    To offer an enhanced and well-controlled nicotine delivery from the refill liquid to the aerosol is a key point to adequately satisfy nicotine cravings using electronic nicotine delivery systems (ENDS). A recent high-power ENDS, exhibiting higher aerosol nicotine delivery than older technologies, was used. The particle size distribution was measured using a cascade impactor. The effects of the refill liquid composition on the nicotine content of each size-fraction in the submicron range were investigated. Nicotine was quantified by liquid chromatography coupled with tandem mass spectrometry. Particle size distribution of the airborne refill liquid and the aerosol nicotine demonstrated that the nicotine is equally distributed in droplets regardless of their size. Results also proved that the nicotine concentration in aerosol was significantly lower compared to un-puffed refill liquid. A part of the nicotine may be left in the ENDS upon depletion, and consequently a portion of the nicotine may not be transferred to the user. Thus, new generation high-power ENDS associated with propylene glycol/vegetable glycerin (PG/VG) based solvent were very efficient to generate carrier-droplets containing nicotine molecules with a constant concentration. Findings highlighted that a portion of the nicotine in the refill liquid may not be transferred to the user.

  19. Need for generic, innovative and geometric deliveries in developing self-sustaining capacity building in remote sensing

    Science.gov (United States)

    Gupta, R. K.; Balamanikavelu, P. M.; Vijayan, D.; Prasad, T. S.

    Everybody uses a bulb to illustrate an idea but nobody shows where the current comes from. Majority of remote sensing user community comes from natural and social sciences domain while remote sensing technology evolves from physical and engineering sciences. To ensure inculcation and internalization of remote sensing technology by application/resource scientists, trainer needs to transfer physical and engineering concepts in geometric manner. Here, the steering for the transfer of knowledge (facts, procedures, concepts and principles) and skills (thinking, acting, reacting and interacting) needs to take the trainees from Known to Unknown, Concrete to Abstract, Observation to Theory and Simple to Complex. In the initial stage of training/education, experiential learning by instructor led exploring of thematic details in false colour composite (FCC) as well as in individual black and white spectral band(s) imagery by trainees not only creates interest, confidence build-up and orientation towards purposeful learning but also helps them to overcome their inhibitions towards the physical and engineering basal. The methodology to be adopted has to inculcate productive learning, emphasizing more on thinking and trial and error aspects as opposed to reproductive learning based dominantly on being told and imitation. The delivery by trainer needs to ensure dynamic, stimulating and effective discussions through deluging questions pertaining to analysis, synthesis and evaluation nature. This would ensure proactive participation from trainees. Hands-on module leads to creative concretization of concepts. To keep the trainees inspired to learn in an auto mode during post-training period, they need to consciously swim in the current and emerging knowledge pool during training programme. This is achieved through assignment of seminar delivery task to the trainees. During the delivery of seminar, peers and co-trainees drive the trainee to communicate the seminar content not only

  20. Development of an Injectable Calcium Phosphate/Hyaluronic Acid Microparticles System for Platelet Lysate Sustained Delivery Aiming Bone Regeneration.

    Science.gov (United States)

    Babo, Pedro S; Santo, Vítor E; Gomes, Manuela E; Reis, Rui L

    2016-11-01

    Despite the biocompatibility and osteoinductive properties of calcium phosphate (CaP) cements their low biodegradability hampers full bone regeneration. Herein the incorporation of CaP cement with hyaluronic acid (HAc) microparticles loaded with platelet lysate (PL) to improve the degradability and biological performance of the cements is proposed. Cement formulations incorporating increasing weight ratios of either empty HAc microparticles or microparticles loaded with PL (10 and 20 wt%) are developed as well as cements directly incorporating PL. The direct incorporation of PL improves the mechanical properties of the plain cement, reaching values similar to native bone. Morphological analysis shows homogeneous particle distribution and high interconnectivity between the HAc microparticles. The cements incorporating PL (with or without the HAc microparticles) present a sustained release of PL proteins for up to 8 d. The sustained release of PL modulates the expression of osteogenic markers in seeded human adipose tissue derived stem cells, thus suggesting the stimulatory role of this hybrid system toward osteogenic commitment and bone regeneration applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Mechanically tuned nanocomposite coating on titanium metal with integrated properties of biofilm inhibition, cell proliferation, and sustained drug delivery.

    Science.gov (United States)

    Mishra, Sandeep K; Teotia, Arun K; Kumar, Ashok; Kannan, Sanjeevi

    2017-01-01

    The clinical success of coated implants in executing biological functions inclusive of sustainable drug release and long term antibacterial activity without antibiotics is critical. To this aim, a nanohybrid of silver nanoparticles (AgNPs) cored in polyvinyl alcohol nanocapsules (Ag-PVA NCs) embedded in chitosan (CS) matrix loaded with anti-inflammatory drug naproxen was prepared. The synthesized nanohybrids that were subjected to coatings on (3-aminopropyl)triethoxysilane (APTES) treated titanium (Ti) metal exhibited dual role of excellent inhibition on biofilm formation and sustained drug release. These dual characteristics are achieved mainly based on intrinsic antibacterial property of AgNPs and differential entrapment of drug in PVA polymeric shell of AgNPs and CS matrix. The coatings also demonstrated enhanced mechanical properties with increasing inorganic filler and stress shielding on Ti metal. The biocompatibility tests involving adhesion, proliferation and differentiation of osteoblast cells demonstrated the efficacy of Ag-PVA NCs embedded in CS matrix as a suitable coating material for orthopedic applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. ET-37EFFICACY OF INTRACRANIAL DELIVERY OF DICHLOROACETATE AND CARBOPLATIN VIA AN LCP POLYMER MICROCAPSULE DEVICE IN AN EXPERIMENTAL GLIOMA MODEL

    Science.gov (United States)

    Mangraviti, Antonella; Jin, Yike; Sy, Jay; Wang, Yuan; Raghavan, Tula; Hastings-Spaine, Lindsey; Olivi, Alessandro; Tyler, Betty; Brem, Henry

    2014-01-01

    BACKGROUND: Multi-targeted therapy is a promising strategy for patients with glioblastoma and controlled delivery of these chemotherapeutics is crucial for effective intracranial chemotherapy. Studies combining platinum pharmacophores with apoptosis inducers, such as Dichloroacetae (DCA), suggest that DCA enhances the sensitivity of cancer cells to platinum compounds. We assessed the efficacy of DCA in combination with Carboplatin (CB) delivered from a biocompatible liquid crystal polymer (LCP) microcapsule in an experimental glioma model in rats. METHODS: In vitro studies were performed to assess the cytotoxicity of DCA and CB on F98 rodent glioma cells. Efficacy was assessed in vivo in rats with intracranially implanted F98 with intracranial implantation of 50% DCA and 5% CB wafers, in monotherapy and in combination. A second study assessed the efficacy of DCA and CB released from an LCP microcapsule as a multi-drug delivery device. RESULTS: The IC50 values for DCA and CB at 24 hours were 70mM and 39mM(R2 =0.989 and 0.948, respectively). The initial efficacy study showed no difference in median survival between the control group and either DCA or CB monotherapy treatments. However, the animals that received CB wafer in combination with DCA wafer had significantly increased survival as compared to the control group (p = 0.016). The microcapsule efficacy study showed that animals given intracranial LCP microcapsule loaded with 5% CB/pCPP:SA and 50% DCA/pCPP:SA had significant improvement in survival (p= 0.0042 vs. control). CONCLUSION: We show that the intracranial delivery of Dichloroacetate and Carboplatin significantly increases survival in an experimental glioma model, when delivered via polymeric wafer as well as when delivered from LCP microcapsule. The LCP microcapsule is a safe and effective method for intracranial dual-drug delivery and may be a novel strategy for obtaining controlled release of multiple drugs with drug-specific kinetics and independent

  3. Evaluation of carbopol-methyl cellulose based sustained-release ocular delivery system for pefloxacin mesylate using rabbit eye model.

    Science.gov (United States)

    Sultana, Yasmin; Aqil, M; Ali, Asgar; Zafar, Shadaab

    2006-01-01

    The major purpose of this study was to develop and characterize a series of carbopol- and methyl cellulose-based solutions as the in situ gelling vehicles for ophthalmic drug delivery. The rheological properties, in vitro release as well as in vivo pharmacological response of a combination of polymer solutions, including carbopol and methyl cellulose, were evaluated. It was found that the optimum concentration of carbopol solution for the in situ gel-forming delivery systems was 0.3% (w/w), and that for methyl cellulose solution was 1.5% (w/w). The mixture of 0.3% carbopol and 1.5% methyl cellulose solutions showed a significant enhancement in gel strength in the physiological condition; this gel mixture was also found to be free flowing at pH 4.0 and 25 degrees C. The rheological behaviors of carbopol/methyl cellulose solution were not affected by the incorporation of the drug. Drug levels in the aqueous humor of the rabbits were well above the MIC-values of relevant bacteria after 12 hours, the results of an optimized formulation containing 0.18% of pefloxacin mesylate compared well with the 0.3% marketed eye drop formulation, indicating our formulation to be significantly better considering that a similar effect was obtained at half the concentration. Both the in vitro release and in vivo pharmacological studies indicated that the carbopol/methyl cellulose solution had better ability to retain drug than did the carbopol or methyl cellulose solutions alone. The results demonstrated that the carbopol/methyl cellulose mixture can be used as an in situ gelling vehicle to enhance the ocular bioavailability of pefloxacin mesylate.

  4. Percutaneous Steerable Robotic Tool Delivery Platform and Metal MEMS Device for Tissue Manipulation and Approximation: Closure of Patent Foramen Ovale in an Animal Model

    Science.gov (United States)

    Vasilyev, Nikolay V.; Gosline, Andrew H.; Butler, Evan; Lang, Nora; Codd, Patrick J.; Yamauchi, Haruo; Feins, Eric N.; Folk, Chris R.; Cohen, Adam L.; Chen, Richard; Zurakowski, David; del Nido, Pedro J.; Dupont, Pierre E

    2013-01-01

    Background Beating-heart image-guided intracardiac interventions have been evolving rapidly. To extend the domain of catheter-based and transcardiac interventions into reconstructive surgery, a new robotic tool delivery platform (TDP) and tissue approximation device have been developed. Initial results employing these tools to perform patent foramen ovale (PFO) closure are described. Methods and Results A robotic TDP comprised of superelastic metal tubes provides the capability of delivering and manipulating tools and devices inside the beating heart. A new device technology is also presented that utilizes a metal-based MicroElectroMechanical Systems (MEMS) manufacturing process to produce fully-assembled and fully-functional millimeter-scale tools. As a demonstration of both technologies, a PFO creation and closure was performed in a swine model. In the first group of animals (N=10), a preliminary study was performed. The procedural technique was validated with a transcardiac handheld delivery platform and epicardial echocardiography, video-assisted cardioscopy and fluoroscopy. In the second group (N=9), the procedure was performed percutaneously using the robotic TDP under epicardial echocardiography and fluoroscopy imaging. All PFO’s were completely closed in the first group. In the second group, the PFO was not successfully created in 1 animal, and the defects were completely closed in 6 of the 8 remaining animals. Conclusions In contrast to existing robotic catheter technologies, the robotic TDP utilizes a combination of stiffness and active steerability along its length to provide the positioning accuracy and force application capability necessary for tissue manipulation. In combination with a MEMS tool technology, it can enable reconstructive procedures inside the beating heart. PMID:23899870

  5. Human resources for health strategies adopted by providers in resource-limited settings to sustain long-term delivery of ART: a mixed-methods study from Uganda.

    Science.gov (United States)

    Zakumumpa, Henry; Taiwo, Modupe Oladunni; Muganzi, Alex; Ssengooba, Freddie

    2016-10-19

    Human resources for health (HRH) constraints are a major barrier to the sustainability of antiretroviral therapy (ART) scale-up programs in Sub-Saharan Africa. Many prior approaches to HRH constraints have taken a top-down trend of generalized global strategies and policy guidelines. The objective of the study was to examine the human resources for health strategies adopted by front-line providers in Uganda to sustain ART delivery beyond the initial ART scale-up phase between 2004 and 2009. A two-phase mixed-methods approach was adopted. In the first phase, a survey of a nationally representative sample of health facilities (n = 195) across Uganda was conducted. The second phase involved in-depth interviews (n = 36) with ART clinic managers and staff of 6 of the 195 health facilities purposively selected from the first study phase. Quantitative data was analysed based on descriptive statistics, and qualitative data was analysed by coding and thematic analysis. The identified strategies were categorized into five themes: (1) providing monetary and non-monetary incentives to health workers on busy ART clinic days; (2) workload reduction through spacing ART clinic appointments; (3) adopting training workshops in ART management as a motivation strategy for health workers; (4) adopting non-physician-centred staffing models; and (5) devising ART program leadership styles that enhanced health worker commitment. Facility-level strategies for responding to HRH constraints are feasible and can contribute to efforts to increase country ownership of HIV programs in resource-limited settings. Consideration of the human resources for health strategies identified in the study by ART program planners and managers could enhance the long-term sustainment of ART programs by providers in resource-limited settings.

  6. Functional validation of an implantable medical dosing device by MRI at 3T.

    Science.gov (United States)

    Anderson, Jeff R; Ferrati, Silvia; Karmonik, Chistof; Grattoni, Alessandro

    2014-01-01

    Sustained release of a small molecule from a prototype implantable drug delivery device was monitored via MRI in an ex vivo tissue phantom over a period of two days. T1 mapping was used as a method to quantify analyte concentration. Continuous, controlled release was observed. The MRI methodology was thus found to be appropriate for device validation and quality assurance/control.

  7. Sustaining and improving an international service-learning partnership: Evaluation of an evidence-based service delivery model.

    Science.gov (United States)

    Hayward, Lorna M; Li, Li

    2017-06-01

    International service learning (ISL) is an instructional method used by physical therapist educators in the United States (US) to prepare students for rendering culturally competent care. ISL is a faculty led student learning opportunity that includes academic instruction and community service in an international context. Research exists that explores student experiences with ISL, but studies that evaluate ISL partnerships and include global stakeholder feedback are lacking. The purposes of this study were to: 1) integrate a partnership evaluation component into an existing curriculum-based ISL model and 2) through evaluation identify benefits, drawbacks, and suggestions for improving and sustaining the academic-community partnership. Community-based participatory research design using a mixed methods approach was used to evaluate a ISL partnership between a US-based physical therapy program and a service site in Ecuador. Participants were 31 staff working at the global service site. Over three years, 11 interviews were conducted and 26 surveys were administered to global partner staff. Data were analyzed using qualitative thematic content analysis and descriptive statistics. Partnership benefits included the following: continuity of ISL team leadership, targeted rehabilitative efforts, sensitivity to cultural norms, respectful communication, and interaction with local community. Drawbacks were as follows: deficits in cultural awareness, language barriers, and poor treatment carryover. Suggestions for sustaining the relationship incorporated: additional pre-trip communication, education of staff, and improved language skills. As more US teams deliver clinical services abroad, intentional evaluation approaches must include the global stakeholder in the planning, implementation, and evaluation phases to maximize partnerships benefits.

  8. Calcium Alginate-Neusilin US2 Nanocomposite Microbeads for Oral Sustained Drug Delivery of Poor Water Soluble Drug Aceclofenac Sodium

    Directory of Open Access Journals (Sweden)

    Manjanna Kolammanahalli Mallappa

    2015-01-01

    Full Text Available The aim of the present study was to formulate and investigate the calcium alginate- (CA- Neusilin US2 nanocomposite microbeads containing preconcentrate of aceclofenac sodium (ACF-Na liquid microemulsion (L-ME for enhancement of oral bioavailability. The preconcentrate L-ME is prepared by using Labrafac PG, Labrasol, and Span 80 as oil, surfactant, and cosurfactant, respectively. The solid CA nanocomposite microbeads of L-ME prepared by microemulsification internal gelation technique using sodium alginate (SA gelling agent, Neusilin US2 as adsorbent, and calcium chloride as crosslinking agent. L-ME has good thermodynamic stability; globule size was found to be 32.4 nm with polydispersity index 0.219 and −6.32 mV zeta potential. No significant interactions of excipients, drug in the formulations observed by FT-IR, DSC and XPRD. The concentration of SA and Neusilin US2 influences the flow properties, mean particle size, mechanical strength, drug entrapment efficiency, and percentage of drug release. All the formulations show minimum drug release in simulated gastric fluid (SGF pH 1.2 for initial 2 h, maximum drug release in pH 6.8 phosphate buffer solution (PBS at 6 h, followed by sustaining in simulated intestinal fluid (SIF of pH 7.4 up to 12 h. The interaction of SA with Neusilin US2 creates a thick thixotropic gel network structure which acts as barrier to control the release of drug in the alkaline pH environment. Neusilin US2 is a novel filler used to convert L-ME into solid nanocomposite microbeads to enhance dissolution rate of poor water soluble drugs sustaining the drug release for prolonged period of time.

  9. Calcium Alginate-Neusilin US2 Nanocomposite Microbeads for Oral Sustained Drug Delivery of Poor Water Soluble Drug Aceclofenac Sodium.

    Science.gov (United States)

    Mallappa, Manjanna Kolammanahalli; Kesarla, Rajesh; Banakar, Shivakumar

    2015-01-01

    The aim of the present study was to formulate and investigate the calcium alginate- (CA-) Neusilin US2 nanocomposite microbeads containing preconcentrate of aceclofenac sodium (ACF-Na) liquid microemulsion (L-ME) for enhancement of oral bioavailability. The preconcentrate L-ME is prepared by using Labrafac PG, Labrasol, and Span 80 as oil, surfactant, and cosurfactant, respectively. The solid CA nanocomposite microbeads of L-ME prepared by microemulsification internal gelation technique using sodium alginate (SA) gelling agent, Neusilin US2 as adsorbent, and calcium chloride as crosslinking agent. L-ME has good thermodynamic stability; globule size was found to be 32.4 nm with polydispersity index 0.219 and -6.32 mV zeta potential. No significant interactions of excipients, drug in the formulations observed by FT-IR, DSC and XPRD. The concentration of SA and Neusilin US2 influences the flow properties, mean particle size, mechanical strength, drug entrapment efficiency, and percentage of drug release. All the formulations show minimum drug release in simulated gastric fluid (SGF) pH 1.2 for initial 2 h, maximum drug release in pH 6.8 phosphate buffer solution (PBS) at 6 h, followed by sustaining in simulated intestinal fluid (SIF) of pH 7.4 up to 12 h. The interaction of SA with Neusilin US2 creates a thick thixotropic gel network structure which acts as barrier to control the release of drug in the alkaline pH environment. Neusilin US2 is a novel filler used to convert L-ME into solid nanocomposite microbeads to enhance dissolution rate of poor water soluble drugs sustaining the drug release for prolonged period of time.

  10. The impact of flavour, device type and warning messages on youth preferences for electronic nicotine delivery systems: evidence from an online discrete choice experiment.

    Science.gov (United States)

    Shang, Ce; Huang, Jidong; Chaloupka, Frank J; Emery, Sherry L

    2017-11-02

    To examine the impact of flavour, device type and health warning messages on youth preference for electronic nicotine delivery systems (ENDS), and to provide evidence and data to inform the Food and Drug Administration's potential regulatory actions on ENDS. An online discrete choice experiment was conducted in September 2015. Each participant was given nine choice sets and asked to choose one out of two alternative ENDS products, with varying characteristics in three attributes (flavour, device type and warning message). The impact of the attributes on the probability of choosing ENDS was analysed using conditional and nested logit regressions, controlling for individual sociodemographic characteristics and current smoking status. A general population sample of 515 participants (50 ever-users and 465 never-users of ENDS) aged 14-17 years were recruited to complete the experiment using an online panel. Fruit/sweets/beverage flavours significantly increase the probability of choosing ENDS among youth (pe-cigarettes, increase (p<0.05) the probability of choosing ENDS among adolescent never-users. Warning messages reduce (p<0.01) the probability of choosing ENDS among never-users. Restricting fruit/sweets/beverage flavours in ENDS, regulating modifiable vaping devices and adopting strong health warning messages may reduce the uptake of ENDS among youth. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Tissue effects in vessel sealing and transection from an ultrasonic device with more intelligent control of energy delivery

    OpenAIRE

    Broughton D; Welling AL; Monroe EH; Pirozzi K; Schulte JB; Clymer JW

    2013-01-01

    Duan Broughton,1 Alissa L Welling,1 Emily H Monroe,1 Kristen Pirozzi,2 John B Schulte,1 Jeffrey W Clymer1 1Ethicon Endo-Surgery, Inc., Cincinnati, OH, 2University of Central Florida, Orlando, FL, USA Background: Ultrasonic surgical devices have been demonstrated to provide excellent hemostasis, efficient transection, minimal lateral thermal damage, low smoke generation, and no risk of electrical current passage to the patient. These benefits originate from the inherent characteristics of the...

  12. Using Mobile Devices in Environmental Education and Education for Sustainable Development—Comparing Theory and Practice in a Nation Wide Survey

    Directory of Open Access Journals (Sweden)

    Steffen Schaal

    2015-07-01

    Full Text Available Mobile electronic devices (MED with integrated GPS receivers are increasingly popular in environmental education (EE and education for sustainable development (ESD. This paper aims at identifying the possible applications of these devices, as well as identifying obstacles to such utilities. Therefore, a two-part study was conducted: An expert Delphi study and a nationwide online survey in Germany and Austria. In this paper, the results of the online survey are reported and compared to the findings of the Delphi study. The questionnaire of the online survey was based on a theoretical framework comprising different dimensions for the use of MED. Overall, 120 projects were included in the study. The most common target groups were school classes and the devices most frequently used were GPS receivers. The projects addressed the criteria of ESD, such as elaboration of local/global perspectives of sustainability and competencies of EE like pro-environmental behavior or attitudes. All projects were classified according to their educational design in a 2 × 2-scheme. The most common activities were predefined routes within a narrow instructional setting. Divergences between expert views and practical realization are identified and discussed.

  13. Development of lovastatin-loaded poly(lactic acid microspheres for sustained oral delivery: in vitro and ex vivo evaluation

    Directory of Open Access Journals (Sweden)

    Guan QG

    2015-02-01

    Full Text Available Qigang Guan,1 Wei Chen,2 Xianming Hu2 1Department of Cardiology, The First Affiliated Hospital of China Medical University, Shenyang, People’s Republic of China; 2Department of Pharmaceutical, Shenyang Institute of Pharmaceutical Industry, Shenyang, People’s Republic of China Background: A novel lovastatin (LVT-loaded poly(lactic acid microsphere suitable for oral administration was developed in this study, and in vitro and in vivo characteristics were evaluated. Methods: The designed microspheres were obtained by an improved emulsion-solvent evaporation method. The morphological examination, particle size, encapsulation ratio, drug loading, and in vitro release were characterized. Pharmacokinetics studies were used to show that microspheres possess more advantages than the conventional formulations. Results: By using the emulsion-solvent evaporation method, it was simple to prepare microspheres and easy to scale up production. The morphology of formed microspheres showed a spherical shape with a smooth surface, without any particle aggregation. Mean size of the microspheres was 2.65±0.69 µm; the encapsulation efficiency was 92.5%±3.6%, and drug loading was 16.7%±2.1%. In vitro release indicated that the LVT microspheres had a well-sustained release efficacy, and ex vivo studies showed that after LVT was loaded to microspheres, the area under the plasma concentration-time curve from zero to the last measurable plasma concentration point and the extrapolation to time infinity increased significantly, which represented 2.63-fold and 2.49-fold increases, respectively, compared to suspensions. The rate of ex vivo clearance was significantly reduced. Conclusion: This research proved that poly(lactic acid microspheres can significantly prolong the drug circulation time in vivo and can also significantly increase the relative bioavailability of the drug. Keywords: lovastatin, microspheres, PLA, in vitro release, pharmacokinetics 

  14. Autologous Cell Delivery to the Skin-Implant Interface via the Lumen of Percutaneous Devices in vitro

    Directory of Open Access Journals (Sweden)

    Antonio Peramo

    2010-11-01

    Full Text Available Induced tissue regeneration around percutaneous medical implants could be a useful method to prevent the failure of the medical device, especially when the epidermal seal around the implant is disrupted and the implant must be maintained over a long period of time. In this manuscript, a novel concept and technique is introduced in which autologous keratinocytes were delivered to the interfacial area of a skin-implant using the hollow interior of a fixator pin as a conduit. Full thickness human skin explants discarded from surgeries were cultured at the air-liquid interface and were punctured to fit at the bottom of hollow cylindrical stainless steel fixator pins. Autologous keratinocytes, previously extracted from the same piece of skin and cultured separately, were delivered to the specimens thorough the interior of the hollow pins. The delivered cells survived the process and resembled undifferentiated epithelium, with variations in size and shape. Viability was demonstrated by the lack of morphologic evidence of necrosis or apoptosis. Although the cells did not form organized epithelial structures, differentiation toward a keratinocyte phenotype was evident immunohistochemically. These results suggest that an adaptation of this technique could be useful for the treatment of complications arising from the contact between skin and percutaneous devices in vivo.

  15. Dosimetric Improvements with a Novel Breast Stereotactic Radiotherapy Device for Delivery of Preoperative Partial-Breast Irradiation.

    Science.gov (United States)

    Snider, James W; Mutaf, Yildirim; Nichols, Elizabeth; Hall, Andrea; Vadnais, Patrick; Regine, William F; Feigenberg, Steven J

    2017-01-01

    Partial-breast irradiation (PBI) with external-beam radiotherapy has produced higher than expected rates of fair-to-poor cosmesis. Worsened outcomes have been correlated with larger volumes of breast tissue exposed to radiation. A novel breast-specific stereotactic radiotherapy (BSRT) device (BSRTD) has been developed at our institution and has shown promise in delivering highly conformal dose distributions. We compared normal tissue sparing with this device with that achieved with intensity-modulated radiation therapy (IMRT)-PBI. Fifteen women previously treated with breast conservation therapy were enrolled on an institutional review board-approved protocol. Each of them underwent CT simulation in the prone position using the BSRTD-specific immobilization system. Simulated postoperative and preoperative treatment volumes were generated based on surgical bed/clip position. Blinded planners generated IMRT-PBI plans and BSRT plans for each set of volumes. These plans were compared based on clinically validated markers for cosmetic outcome and toxicity using a Wilcoxon rank-sum test. The BSRT plans consistently reduced the volumes receiving each of several dose levels (Vx) to breast tissue, the chest wall, the lung, the heart, and the skin in both preoperative and postoperative settings (p < 0.05). Preoperative BSRT yielded particularly dramatic improvements. The novel BSRTD has demonstrated significant dosimetric benefits over IMRT-PBI. Further investigation is currently proceeding through initial clinical trials. © 2016 S. Karger AG, Basel.

  16. Microsensing networks for sustainable cities

    CERN Document Server

    Lambrechts, Johannes

    2016-01-01

    This book explores the microsensing technologies and systems now available to monitor the quality of air and water within the urban environment and examines their role in the creation of sustainable cities against the background of the challenges posed by rapid urbanization. The opening section addresses the theoretical and conceptual background of microsensing networks. The coverage includes detailed description of microsensors, supported by design-specific equations, and clear explanation of the ways in which devices that harvest energy from ambient sources can detect and quantify pollution. The practical application of such systems in addressing environmental impacts within cities and in sustainable urban planning is then discussed with the aid of case studies in developing countries. The book will be of interest to all who wish to understand the benefits of microsensing networks in promoting sustainable cities through better delivery of information on health hazards and improved provision of data to envir...

  17. Tuning aerosol performance using the multibreath Orbital® dry powder inhaler device: controlling delivery parameters and aerosol performance via modification of puck orifice geometry.

    Science.gov (United States)

    Zhu, Bing; Young, Paul M; Ong, Hui Xin; Crapper, John; Flodin, Carina; Qiao, Erin Lin; Phillips, Gary; Traini, Daniela

    2015-07-01

    The current study presents a new approach to tackle high-dose lung delivery using a prototype multibreath Orbital® dry powder inhaler (DPI). One of the key device components is the "puck" (aerosol sample chamber) with precision-engineered outlet orifice(s) that control the dosing rate. The influence of puck orifice geometry and number of orifices on the performance of mannitol aerosols were studied. Pucks with different orifice configurations were filled with 400 mg of spray-dried mannitol and tested in the Orbital® DPI prototype. The emitted dose and overall aerodynamic performance across a number of "breaths" were studied using a multistage liquid impinger. The aerosol performances of the individual actuations were investigated using in-line laser diffraction. The emptying rate of all pucks was linear between 20% and 80% cumulative drug released (R(2) > 0.98), and the amount of formulation released per breath could be controlled such that the device was empty after 2 to 11 breath maneuvers. The puck-emptying rate linearly related to the orifice hole length (R(2) > 0.95). Mass median aerodynamic diameters of the emitted aerosol ranged from 4.03 to 4.62 μm and fine particle fraction (≤6.4 μm) were 50%-66%. Laser diffraction suggested that the aerosol performance and emptying rates were not dependent on breath number, showing consistent size distribution profiles. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  18. Ethylene vinyl acetate (EVA) as a new drug carrier for 3D printed medical drug delivery devices

    DEFF Research Database (Denmark)

    Genina, Natalja; Hollander, Jenny; Jukarainen, Harri

    2016-01-01

    The main purpose of this work was to investigate the printability of different grades of ethylene vinyl acetate (EVA) copolymers as new feedstock material for fused-deposition modeling (FDM™)-based 3D printing technology in fabrication of custom-made T-shaped intrauterine systems (IUS......) and subcutaneous rods (SR). The goal was to select an EVA grade with optimal properties, namely vinyl acetate content, melting index, flexural modulus, for 3D printing of implantable prototypes with the drug incorporated within the entire matrix of the medical devices. Indomethacin was used as a model drug...... affected the drug release profiles from the filaments and printed prototype products: faster release from the prototypes over 30 days in the in vitro tests. To conclude, this study indicates that certain grades of EVA were applicable feedstock material for 3D printing to produce drug-loaded implantable...

  19. Novel device for continuous spatial control and temporal delivery of nitric oxide for in vitro cell culture

    Directory of Open Access Journals (Sweden)

    Genevieve E. Romanowicz

    2013-01-01

    Full Text Available Nitric oxide (NO is an ubiquitous signaling molecule of intense interest in many physiological processes. Nitric oxide is a highly reactive free radical gas that is difficult to deliver with precise control over the level and timing that cells actually experience. We describe and characterize a device that allows tunable fluxes and patterns of NO to be generated across the surface upon which cells are cultured. The system is based on a quartz microscope slide that allows for controlled light levels to be applied to a previously described photosensitive NO-releasing polydimethylsiloxane (PDMS. Cells are cultured in separate wells that are either NO-releasing or a chemically similar PDMS that does not release NO. Both wells are then top coated with DowCorning RTV-3140 PDMS and a polydopamine/gelatin layer to allow cells to grow in the culture wells. When the waveguide is illuminated, the surface of the quartz slide propagates light such that the photosensitive polymer is evenly irradiated and generates NO across the surface of the cell culture well and no light penetrates into the volume of the wells where cells are growing. Mouse smooth muscle cells (MOVAS were grown in the system in a proof of principle experiment, whereby 60% of the cells were present in the NO-releasing well compared to control wells after 17 h. The compelling advantage of illuminating the NO-releasing polymers with the waveguide system is that light can be used to tunably control NO release while avoiding exposing cells to optical radiation. This device provides means to quantitatively control the surface flux, timing and duration of NO cells experience and allows for systematic study of cellular response to NO generated at the cell/surface interface in a wide variety of studies.

  20. Single-Sided Digital Microfluidic (SDMF Devices for Effective Coolant Delivery and Enhanced Two-Phase Cooling

    Directory of Open Access Journals (Sweden)

    Sung-Yong Park

    2016-12-01

    Full Text Available Digital microfluidics (DMF driven by electrowetting-on-dielectric (EWOD has recently been attracting great attention as an effective liquid-handling platform for on-chip cooling. It enables rapid transportation of coolant liquid sandwiched between two parallel plates and drop-wise thermal rejection from a target heating source without additional mechanical components such as pumps, microchannels, and capillary wicks. However, a typical sandwiched configuration in DMF devices only allows sensible heat transfer, which seriously limits heat rejection capability, particularly for high-heat-flux thermal dissipation. In this paper, we present a single-sided digital microfluidic (SDMF device that enables not only effective liquid handling on a single-sided surface, but also two-phase heat transfer to enhance thermal rejection performance. Several droplet manipulation functions required for two-phase cooling were demonstrated, including continuous droplet injection, rapid transportation as fast as 7.5 cm/s, and immobilization on the target hot spot where heat flux is locally concentrated. Using the SDMF platform, we experimentally demonstrated high-heat-flux cooling on the hydrophilic-coated hot spot. Coolant droplets were continuously transported to the target hot spot which was mitigated below 40 K of the superheat. The effective heat transfer coefficient was stably maintained even at a high heat flux regime over ~130 W/cm2, which will allow us to develop a reliable thermal management module. Our SDMF technology offers an effective on-chip cooling approach, particularly for high-heat-flux thermal management based on two-phase heat transfer.

  1. A statistical study on the development of micro particulate sustained drug delivery system for Losartan potassium by 32 factorial design approach

    Directory of Open Access Journals (Sweden)

    Gokul Khairnar

    2017-06-01

    Full Text Available The purpose of this study was to investigate the effect of polymer and surfactant concentration on drug loading and in vitro drug release of micro particulate drug delivery system of Losartan potassium (LST. Microparticles were prepared by O/O solvent emulsification method. A 32 full factorial design was used to derive statistical equation and construct contour plots to predict responses. The independent variables selected were polymer concentration (A, surfactant concentration (B. Dependent variables were percentage drug loading (Y1 and percentage drug release at 12 h (Y2. The in vitro drug release profile of prepared microparticles was compared with marketed tablet formulation. The release profile of microparticles was found to be sustained as compared to the marketed formulation. The drug loading was found to be in the range of 15.32% (F6 to 22.27% (F5. FT-IR analysis revealed no drug excipient interference. The morphology of evaluated microparticles at −1 level was found to be spherical and smooth in nature while at higher level +1 it was found to be rough, irregular, with erosion, cracks and wrinkles on the surface. In XRD analysis crystalline pattern of pure LST was changed to amorphous pattern when converted to microparticles.

  2. Alternative service delivery models for families with a new speech generating device: Perspectives of parents and therapists.

    Science.gov (United States)

    Anderson, Kate Louise; Balandin, Susan; Stancliffe, Roger James

    2015-04-01

    Research has revealed limitations in the provision of in-person services to families with a new speech generating device (SGD), both in Australia and overseas. Alternative service models such as parent training, peer support and telepractice may offer a solution, but their use with this population has not been researched to date. Using interviews and focus groups, this study explored the experiences and opinions of 13 speech-language pathologists and seven parents regarding alternatives to in-person support and training for families with a new SGD. Data were analysed using grounded theory. Themes explored in this paper include the benefits and drawbacks of alternative service models as well as participants' suggestions for the optimal implementation of these approaches. Participants confirmed the utility of alternative service models, particularly for rural/remote and underserviced clients. Benefits of these models included reduced travel time for families and therapists, as well as enhanced information access, support and advocacy for parents. Participants viewed the provision of ongoing professional support to families as critical, regardless of service modality. Additional issues arising from this study include the need for development of organizational policies, resources and training infrastructure to support the implementation of these alternative service models.

  3. Achievement of field-reversed configuration plasma sustainment via 10 MW neutral-beam injection on the C-2U device

    Science.gov (United States)

    Gota, H.; Binderbauer, M. W.; Tajima, T.; Putvinski, S.; Tuszewski, M.; Dettrick, S.; Garate, E.; Korepanov, S.; Smirnov, A.; Thompson, M. C.; Trask, E.; Yang, X.; Schmitz, L.; Lin, Z.; Ivanov, A. A.; Asai, T.; Allfrey, I.; Andow, R.; Beall, M.; Bolte, N.; Bui, D. Q.; Cappello, M.; Ceccherini, F.; Clary, R.; Cheung, A. H.; Conroy, K.; Deng, B. H.; Douglass, J.; Dunaevsky, A.; Feng, P.; Fulton, D.; Galeotti, L.; Granstedt, E.; Griswold, M.; Gupta, D.; Gupta, S.; Hubbard, K.; Isakov, I.; Kinley, J. S.; Knapp, K.; Magee, R.; Matvienko, V.; Mendoza, R.; Mok, Y.; Necas, A.; Primavera, S.; Onofri, M.; Osin, D.; Rath, N.; Roche, T.; Romero, J.; Schindler, T.; Schroeder, J. H.; Sevier, L.; Sheftman, D.; Sibley, A.; Song, Y.; Steinhauer, L. C.; Valentine, T.; Van Drie, A. D.; Walters, J. K.; Waggoner, W.; Yushmanov, P.; Zhai, K.; The TAE Team

    2017-11-01

    Tri Alpha Energy’s experimental program has demonstrated reliable field-reversed configuration (FRC) formation and sustainment, driven by fast ions via high-power neutral-beam (NB) injection. The world’s largest compact-toroid device, C-2U, was upgraded from C-2 with the following key system upgrades: increased total NB input power from ~4 MW (20 keV hydrogen) to 10+  MW (15 keV hydrogen) with tilted injection angle; enhanced edge-biasing capability inside of each end divertor for boundary/stability control. C-2U experiments with those upgraded systems have successfully demonstrated dramatic improvements in FRC performance and achieved sustainment of advanced beam-driven FRCs with a macroscopically stable and hot plasma state for up to 5+  ms. Plasma diamagnetism in the best discharges has reached record lifetimes of over 11 ms, timescales twice as long as C-2. The C-2U plasma performance, including the sustainment feature, has a strong correlation with NB pulse duration, with the diamagnetism persisting even several milliseconds after NB termination due to the accumulated fast-ion population by NB injection. Power balance analysis shows substantial improvements in equilibrium and transport parameters, whereby electron energy confinement time strongly correlates with electron temperature; i.e. the confinement time in C-2U scales strongly with a positive power of T e.

  4. A Mobile Device App to Reduce Medication Errors and Time to Drug Delivery During Pediatric Cardiopulmonary Resuscitation: Study Protocol of a Multicenter Randomized Controlled Crossover Trial.

    Science.gov (United States)

    Siebert, Johan N; Ehrler, Frederic; Lovis, Christian; Combescure, Christophe; Haddad, Kevin; Gervaix, Alain; Manzano, Sergio

    2017-08-22

    During pediatric cardiopulmonary resuscitation (CPR), vasoactive drug preparation for continuous infusions is complex and time-consuming. The need for individual specific weight-based drug dose calculation and preparation places children at higher risk than adults for medication errors. Following an evidence-based and ergonomic driven approach, we developed a mobile device app called Pediatric Accurate Medication in Emergency Situations (PedAMINES), intended to guide caregivers step-by-step from preparation to delivery of drugs requiring continuous infusion. In a prior single center randomized controlled trial, medication errors were reduced from 70% to 0% by using PedAMINES when compared with conventional preparation methods. The purpose of this study is to determine whether the use of PedAMINES in both university and smaller hospitals reduces medication dosage errors (primary outcome), time to drug preparation (TDP), and time to drug delivery (TDD) (secondary outcomes) during pediatric CPR when compared with conventional preparation methods. This is a multicenter, prospective, randomized controlled crossover trial with 2 parallel groups comparing PedAMINES with a conventional and internationally used drug infusion rate table in the preparation of continuous drug infusion. The evaluation setting uses a simulation-based pediatric CPR cardiac arrest scenario with a high-fidelity manikin. The study involving 120 certified nurses (sample size) will take place in the resuscitation rooms of 3 tertiary pediatric emergency departments and 3 smaller hospitals. After epinephrine-induced return of spontaneous circulation, nurses will be asked to prepare a continuous infusion of dopamine using either PedAMINES (intervention group) or the infusion table (control group) and then prepare a continuous infusion of norepinephrine by crossing the procedure. The primary outcome is the medication dosage error rate. The secondary outcome is the time in seconds elapsed since the oral

  5. Development of a novel CsA-PLGA drug delivery system based on a glaucoma drainage device for the prevention of postoperative fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Zhaoxing; Yu, Xiaobo; Hong, Jiaxu; Liu, Xi [Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai 200031 (China); Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai 200031 (China); Sun, Jianguo, E-mail: sjgsun@126.com [Research Center, Eye & ENT Hospital, Fudan University, Shanghai 200031 (China); Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai 200031 (China); State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200031 (China); Sun, Xinghuai, E-mail: xhsun@shmu.edu.cn [Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai 200031 (China); Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai 200031 (China)

    2016-09-01

    The formation of a scar after glaucoma surgery often leads to unsuccessful control of intraocular pressure, and should be prevented by using a variety of methods. We designed and developed a novel drug delivery system (DDS) comprising cyclosporine A (CsA) and poly(lactic-co-glycolic acid) (PLGA) based on a glaucoma drainage device (GDD) that can continuously release CsA to prevent postoperative fibrosis following glaucoma surgery. The CsA@PLGA@GDD DDS was observed by field emission scanning electron microscopy and revealed an asymmetric pore structure. Thermogravimetric analysis was performed to measure the weight loss and evaluate the thermal stability of the CsA@PLGA@GDD DDS. The in vitro drug release profile of the DDS was studied using high performance liquid chromatography, which confirmed that the DDS released CsA at a stable rate and maintained adequate CsA concentrations for a relatively long time. The biocompatibility of the DDS and the inhibitory effects on the postoperative fibrosis were investigated in vitro using rabbit Tenon's fibroblasts. The in vivo safety and efficacy of the DDS were examined by implanting the DDS into Tenon's capsules in New Zealand rabbits. Bleb morphology, intraocular pressure, anterior chamber reactions, and anterior chamber angiography were studied at a series of set times. The DDS kept the filtration pathway unblocked for a longer time compared with the control GDD. The results indicate that the CsA@PLGA@GDD DDS represents a safe and effective strategy for preventing scar formation after glaucoma surgery. - Highlights: • CsA@PLGA@GDD drug delivery system (DDS) was designed and prepared successfully. • The DDS released CsA at a stable rate for > 3 months. • The DDS kept filtration pathway unblocked for a longer time than control. • CsA@PLGA@GDD DDS prevented glaucoma scar formation as a safe and effective strategy.

  6. A Device to Measure a Smoker’s Puffing Topography and Real-Time Puff-By-Puff “Tar” Delivery

    Directory of Open Access Journals (Sweden)

    Slayford Sandra J.

    2014-07-01

    Full Text Available A device for measuring the flow, duration and volume characteristics of human puffing behaviour when smoking cigarettes is described. Cigarettes are smoked through a holder comprising a measured pressure drop across a critical orifice. The holder also contains a Light Emitting Diode (LED and photodetector that measures light obscuration in order to estimate nicotine-free dry particulate matter (NFDPM, “tar” delivery. All data are recorded on a puff-by-puff basis and displayed in real time. These NFDPM estimates are known as optical “tar” (OT, and are derived from the calibration of the OT measurement versus gravimetric NFDPM yields of cigarettes under a range of smoking regimes. In a test study, puff volumes from 20-80 mL were recorded to ± 6.0% of a pre-set volume, with an absolute error of 4.7 mL for an 80 mL volume drawn on a lit cigarette, and an average error of less than 2.0 mL across the range 20-80 mL. The relationship between NFDPM and OT was linear (R2 = 0.99 and accurate to ± 1.3 mg per cigarette over the range 1-23 mg per cigarette. The device provides an alternative to the widely used part filter methodology for estimating mouth level exposure with an added benefit that no further laboratory smoking replication or analysis is required. When used in conjunction with the part filter methodology, the puffing behaviour recorded can explain anomalies in the data while providing a second independent estimate.

  7. Sustained Neural Stem Cell-Based Intraocular Delivery of CNTF Attenuates Photoreceptor Loss in the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis

    Science.gov (United States)

    Jankowiak, Wanda; Kruszewski, Katharina; Flachsbarth, Kai; Skevas, Christos; Richard, Gisbert; Rüther, Klaus; Braulke, Thomas; Bartsch, Udo

    2015-01-01

    A sustained intraocular administration of neurotrophic factors is among the strategies aimed at establishing treatments for currently untreatable degenerative retinal disorders. In the present study we have analyzed the neuroprotective effects of a continuous neural stem (NS) cell-based intraocular delivery of ciliary neurotrophic factor (CNTF) on photoreceptor cells in the nclf mouse, an animal model of the neurodegenerative lysosomal storage disorder variant late infantile neuronal ceroid lipofuscinosis (vLINCL). To this aim, we genetically modified adherently cultivated NS cells with a polycistronic lentiviral vector encoding a secretable variant of CNTF together with a Venus reporter gene (CNTF-NS cells). NS cells for control experiments (control-NS cells) were modified with a vector encoding the reporter gene tdTomato. Clonal CNTF-NS and control-NS cell lines were established using fluorescent activated cell sorting and intravitreally grafted into 14 days old nclf mice at the onset of retinal degeneration. The grafted cells preferentially differentiated into astrocytes that were attached to the posterior side of the lenses and the vitreal side of the retinas and stably expressed the transgenes for at least six weeks, the latest post-transplantation time point analyzed. Integration of donor cells into host retinas, ongoing proliferation of grafted cells or adverse effects of the donor cells on the morphology of the host eyes were not observed. Quantitative analyses of host retinas two, four and six weeks after cell transplantation revealed the presence of significantly more photoreceptor cells in eyes with grafted CNTF-NS cells than in eyes with grafted control-NS cells. This is the first demonstration that a continuous intraocular administration of a neurotrophic factor attenuates retinal degeneration in an animal model of neuronal ceroid lipofuscinosis. PMID:25992714

  8. Sustained Neural Stem Cell-Based Intraocular Delivery of CNTF Attenuates Photoreceptor Loss in the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis.

    Directory of Open Access Journals (Sweden)

    Wanda Jankowiak

    Full Text Available A sustained intraocular administration of neurotrophic factors is among the strategies aimed at establishing treatments for currently untreatable degenerative retinal disorders. In the present study we have analyzed the neuroprotective effects of a continuous neural stem (NS cell-based intraocular delivery of ciliary neurotrophic factor (CNTF on photoreceptor cells in the nclf mouse, an animal model of the neurodegenerative lysosomal storage disorder variant late infantile neuronal ceroid lipofuscinosis (vLINCL. To this aim, we genetically modified adherently cultivated NS cells with a polycistronic lentiviral vector encoding a secretable variant of CNTF together with a Venus reporter gene (CNTF-NS cells. NS cells for control experiments (control-NS cells were modified with a vector encoding the reporter gene tdTomato. Clonal CNTF-NS and control-NS cell lines were established using fluorescent activated cell sorting and intravitreally grafted into 14 days old nclf mice at the onset of retinal degeneration. The grafted cells preferentially differentiated into astrocytes that were attached to the posterior side of the lenses and the vitreal side of the retinas and stably expressed the transgenes for at least six weeks, the latest post-transplantation time point analyzed. Integration of donor cells into host retinas, ongoing proliferation of grafted cells or adverse effects of the donor cells on the morphology of the host eyes were not observed. Quantitative analyses of host retinas two, four and six weeks after cell transplantation revealed the presence of significantly more photoreceptor cells in eyes with grafted CNTF-NS cells than in eyes with grafted control-NS cells. This is the first demonstration that a continuous intraocular administration of a neurotrophic factor attenuates retinal degeneration in an animal model of neuronal ceroid lipofuscinosis.

  9. Sustained expression of CYPs and DNA adduct accumulation with continuous exposure to PCB126 and PCB153 through a new delivery method: Polymeric implants

    Directory of Open Access Journals (Sweden)

    Farrukh Aqil

    2014-01-01

    Full Text Available A new delivery method via polymeric implants was used for continuous exposure to PCBs. Female Sprague-Dawley rats received subcutaneous polymeric implants containing PCB126 (0.15% load, PCB153 (5% load, or both, for up to 45 d and release kinetics and tissue distribution were measured. PCB153 tissue levels on day 15 were readily detected in lung, liver, mammary and serum, with highest levels in the mammary tissue. PCB126 was detected only in liver and mammary tissues. However, a completely different pharmacokinetics was observed on co-exposure of PCB153 and PCB126, with a 1.8-fold higher levels of PCB153 in the liver whereas a 1.7-fold lower levels in the mammary tissue. PCB126 and PCB153 caused an increase in expression of key PCB-inducible enzymes, CYP 1A1/2 and 2B1/2, respectively. Serum and liver activities of the antioxidant enzymes, PON1 and PON3, and AhR transcription were also significantly increased by PCB126. 32P-postlabeling for polar and lipophilic DNA-adducts showed significant quantitative differences: PCB126 increased 8-oxodG, an oxidative DNA lesion, in liver and lung tissues. Adduct levels in the liver remained upregulated up to 45 d, while some lung DNA adducts declined. This is the first demonstration that continuous low-dose exposure to PCBs via implants can produce sustained tissue levels leading to the accumulation of DNA-adducts in target tissue and induction of indicator enzymes. Collectively, these data demonstrate that this exposure model is a promising tool for long-term exposure studies.

  10. Response of Seismically Isolated Steel Frame Buildings with Sustainable Lead-Rubber Bearing (LRB Isolator Devices Subjected to Near-Fault (NF Ground Motions

    Directory of Open Access Journals (Sweden)

    Jong Wan Hu

    2014-12-01

    Full Text Available Base isolation has been used as one of the most wildly accepted seismic protection systems that should substantially dissociate a superstructure from its substructure resting on a shaking ground, thereby sustainably preserving entire structures against earthquake forces as well as inside non-structural integrities. Base isolation devices can operate very effectively against near-fault (NF ground motions with large velocity pulses and permanent ground displacements. In this study, comparative advantages for using lead-rubber bearing (LRB isolation systems are mainly investigated by performing nonlinear dynamic time-history analyses with NF ground motions. The seismic responses with respects to base shears and inter-story drifts are compared according to the installation of LRB isolation systems in the frame building. The main function of the base LRB isolator is to extend the period of structural vibration by increasing lateral flexibility in the frame structure, and thus ground accelerations transferred into the superstructure can dramatically decrease. Therefore, these base isolation systems are able to achieve notable mitigation in the base shear. In addition, they make a significant contribution to reducing inter-story drifts distributed over the upper floors. Finally, the fact that seismic performance can be improved by installing isolation devices in the frame structure is emphasized herein through the results of nonlinear dynamic analyses.

  11. A Mobile Device App to Reduce Time to Drug Delivery and Medication Errors During Simulated Pediatric Cardiopulmonary Resuscitation: A Randomized Controlled Trial.

    Science.gov (United States)

    Siebert, Johan N; Ehrler, Frederic; Combescure, Christophe; Lacroix, Laurence; Haddad, Kevin; Sanchez, Oliver; Gervaix, Alain; Lovis, Christian; Manzano, Sergio

    2017-02-01

    During pediatric cardiopulmonary resuscitation (CPR), vasoactive drug preparation for continuous infusion is both complex and time-consuming, placing children at higher risk than adults for medication errors. Following an evidence-based ergonomic-driven approach, we developed a mobile device app called Pediatric Accurate Medication in Emergency Situations (PedAMINES), intended to guide caregivers step-by-step from preparation to delivery of drugs requiring continuous infusion. The aim of our study was to determine whether the use of PedAMINES reduces drug preparation time (TDP) and time to delivery (TDD; primary outcome), as well as medication errors (secondary outcomes) when compared with conventional preparation methods. The study was a randomized controlled crossover trial with 2 parallel groups comparing PedAMINES with a conventional and internationally used drugs infusion rate table in the preparation of continuous drug infusion. We used a simulation-based pediatric CPR cardiac arrest scenario with a high-fidelity manikin in the shock room of a tertiary care pediatric emergency department. After epinephrine-induced return of spontaneous circulation, pediatric emergency nurses were first asked to prepare a continuous infusion of dopamine, using either PedAMINES (intervention group) or the infusion table (control group), and second, a continuous infusion of norepinephrine by crossing the procedure. The primary outcome was the elapsed time in seconds, in each allocation group, from the oral prescription by the physician to TDD by the nurse. TDD included TDP. The secondary outcome was the medication dosage error rate during the sequence from drug preparation to drug injection. A total of 20 nurses were randomized into 2 groups. During the first study period, mean TDP while using PedAMINES and conventional preparation methods was 128.1 s (95% CI 102-154) and 308.1 s (95% CI 216-400), respectively (180 s reduction, P=.002). Mean TDD was 214 s (95% CI 171-256) and

  12. Economic and organizational sustainability of a negative-pressure portable device for the prevention of surgical-site complications.

    Science.gov (United States)

    Foglia, Emanuela; Ferrario, Lucrezia; Garagiola, Elisabetta; Signoriello, Giuseppe; Pellino, Gianluca; Croce, Davide; Canonico, Silvestro

    2017-01-01

    Surgical-site complications (SSCs) affect patients' clinical pathway, prolonging their hospitalization and incrementing their management costs. The present study aimed to assess the economic and organizational implications of a portable device for negative-pressure wound therapy (NPWT) implementation, compared with the administration of pharmacological therapies alone for preventing surgical complications in patients undergoing general, cardiac, obstetrical-gynecological, or orthopedic surgical procedures. A total of 8,566 hospital procedures, related to the year 2015 from one hospital, were evaluated considering infection risk index, occurrence rates of SSCs, drug therapies, and surgical, diagnostic, and specialist procedures and hematological exams. Activity-based costing and budget impact analyses were implemented for the economic assessment. Patients developing an SSC absorbed i) 64.27% more economic resources considering the length of stay (€ 8,269±2,096 versus € 5,034±2,901, peconomic resources related to hematological and diagnostic procedures (€ 639±117 versus € 449±72, psustainable strategy for reducing the management costs of patients. Economic and organizational savings could be reinvested, thus i) treating a wider population and ii) reducing waiting lists, with a higher effectiveness in terms of a decrease in complications.

  13. Development of a novel CsA-PLGA drug delivery system based on a glaucoma drainage device for the prevention of postoperative fibrosis.

    Science.gov (United States)

    Dai, Zhaoxing; Yu, Xiaobo; Hong, Jiaxu; Liu, Xi; Sun, Jianguo; Sun, Xinghuai

    2016-09-01

    The formation of a scar after glaucoma surgery often leads to unsuccessful control of intraocular pressure, and should be prevented by using a variety of methods. We designed and developed a novel drug delivery system (DDS) comprising cyclosporine A (CsA) and poly(lactic-co-glycolic acid) (PLGA) based on a glaucoma drainage device (GDD) that can continuously release CsA to prevent postoperative fibrosis following glaucoma surgery. The CsA@PLGA@GDD DDS was observed by field emission scanning electron microscopy and revealed an asymmetric pore structure. Thermogravimetric analysis was performed to measure the weight loss and evaluate the thermal stability of the CsA@PLGA@GDD DDS. The in vitro drug release profile of the DDS was studied using high performance liquid chromatography, which confirmed that the DDS released CsA at a stable rate and maintained adequate CsA concentrations for a relatively long time. The biocompatibility of the DDS and the inhibitory effects on the postoperative fibrosis were investigated in vitro using rabbit Tenon's fibroblasts. The in vivo safety and efficacy of the DDS were examined by implanting the DDS into Tenon's capsules in New Zealand rabbits. Bleb morphology, intraocular pressure, anterior chamber reactions, and anterior chamber angiography were studied at a series of set times. The DDS kept the filtration pathway unblocked for a longer time compared with the control GDD. The results indicate that the CsA@PLGA@GDD DDS represents a safe and effective strategy for preventing scar formation after glaucoma surgery. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Laboratory based experiments to assess the use of green and food based compost to improve water quality in a Sustainable Drainage (SUDS) device such as a swale.

    Science.gov (United States)

    Charlesworth, S M; Nnadi, E; Oyelola, O; Bennett, J; Warwick, F; Jackson, R; Lawson, D

    2012-05-01

    Many tonnes of compost are generated per year due to door step composting of both garden and kitchen waste. Whilst there are commercial outlets for the finer grade of compost (nurseries, there is little demand for the coarser material (>25 mm). This paper reports part of a WRAP-sponsored (Waste Resources Action Programme) study which investigated the potential for green (GC) and mixed green and food (MC) composts to be incorporated into Sustainable Drainage (SUDS) devices such as swales, and replace the topsoil (TS) onto which turf is laid or grass seed distributed. However, it is not known whether compost can replace TS in terms of pollutant remediation, both the trapping of polluted particulates and in dealing with hydrocarbons such as oil, but also from a biofilm development and activity perspective. Using laboratory based experiments utilising leaching columns and an investigation of microbiological development in the composts studied, it was found that many of the differences in performance between MC and GC were insignificant, whilst both composts performed better in terms of pollutant retention than TS. Mixed compost in particular could be used in devices where there may be oil spillages, such as the lorry park of a Motorway Service Area due to its efficiency in degrading oil. Samples of GC and MC were found to contain many of the bacteria and fungi necessary for an active and efficient biofilm which would be an argument in their favour for replacement of TS and incorporation in swales. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Assay of 6-gingerol in CO2 supercritical fluid extracts of ginger and evaluation of its sustained release from a transdermal delivery system across rat skin.

    Science.gov (United States)

    Chen, Yan; Zhang, Cuiping; Zhang, Mei; Fu, Xiaobing

    2014-07-01

    Ginger has been widely used as healthy food condiment as well as traditional Chinese medicine since antiquity. Multiple potentials of ginger for treatment of various ailments have been revealed. However, the biological half-life of 6-gingerol (a principal pungent ingredient of ginger) is only 7.23 minutes while taken orally. Delivery of ginger compositions by routes other than oral have scarcely been reported. Therefore, we studied a noninvasive transdermal drug delivery system (TDDS) of ginger to bypass hepatic first pass metabolism, avoid gastrointestinal degradation and achieve long persistent release of effective compositions. After establishment of a HPLC analysis method of 6-gingerol, assays of 6-gingerol were performed to compare two kinds of ginger extracts. Then, the characteristics of transdermal delivery of 6-gingerol in TDDS were exhibited. The results showed that the contents of 6-gingerol in two kinds of ginger extracts were significantly different. The maximal delivery percentage of 6-gingerol across rat skin at 20 h was more than 40% in different TDDS formulations. TDDS may provide long-lasting delivery of ginger compounds.

  16. Drug delivery from ordered mesoporous matrices.

    Science.gov (United States)

    Manzano, Miguel; Colilla, Montserrat; Vallet-Regí, María

    2009-12-01

    Research interest in silica-based ordered mesoporous materials (SMMs) as drug delivery systems has grown drastically in the last few years owing to the great versatility and stability of these mesoporous matrices. This review aims to resume the work carried out in this area so far and the possible applications in biomedical technologies. The different SMMs can be designed and tailored using different chemical strategies according to the drug and clinical necessity. The available channels of SMMs that can be used to store drugs can be opened and closed by different systems, in the so-called stimuli-responsive release devices. These systems could improve the therapeutic efficacy compared with conventional sustained release systems. SMMs offer such a great versatility that can be used both for oral and for local drug delivery, with huge possible applications in different clinical areas.

  17. LCA and Sustainability

    DEFF Research Database (Denmark)

    Moltesen, Andreas; Bjørn, Anders

    2017-01-01

    LCA is often presented as a sustainability assessment tool. This chapter analyses the relationship between LCA and sustainability. This is done by first outlining the history of the sustainability concept, which gained momentum with the Brundtland Commission’s report ‘Our Common Future report...... is then demonstrated, and the strategy of LCA to achieving environmental protection, namely to guide the reduction of environmental impacts per delivery of a function, is explained. The attempt to broaden the scope of LCA, beyond environmental protection, by so-called life cycle sustainability assessment (LCSA......) is outlined. Finally, the limitations of LCA in guiding a sustainable development are discussed....

  18. Porous Hydroxyapatite Bioceramic Scaffolds for Drug Delivery and Bone Regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Loca, Dagnija; Locs, Janis; Salma, Kristine; Gulbis, Juris; Salma, Ilze; Berzina-Cimdina, Liga, E-mail: dagnija.loca@rtu.l [Riga Technical University, Riga Biomaterials innovation and development centre, Pulka 3/3, LV-1007, Riga (Latvia)

    2011-10-29

    The conventional methods of supplying a patient with pharmacologic active substances suffer from being very poorly selective, so that damage can occurs to the healthy tissues and organs, different from the intended target. In addition, high drug doses can be required to achieve the desired effect. An alternative approach is based on the use of implantable delivery tools, able to release the active substance in a controlled way. In the current research local drug delivery devices containing 8mg of gentamicin sulphate were prepared using custom developed vacuum impregnation technique. In vitro dissolution tests showed that gentamicin release was sustained for 12h. In order to decrease gentamicin release rate, biopolymer coatings were applied and coating structure investigated. The results showed that gentamicin release can be sustained for more than 70h for poly({epsilon}-caprolactone) coated calcium phosphate scaffolds. From poly lactic acid and polyvinyl alcohol coated scaffolds gentamicin was released within 20h and 50h, respectively.

  19. Macro-perspective on the first decade of South African housing delivery and its contribution towards the formation of sustainable settlements and communities

    CSIR Research Space (South Africa)

    Napier, Mark

    2005-12-01

    Full Text Available The economic, social and spatial impacts of the national state housing programme in South Africa over the last ten years have been significant. And yet the ability of the programme to produce settlements which can be described as 'sustainable' has...

  20. A nanomedicine approach to effectively inhibit contracture during bladder acellular matrix allograft-induced bladder regeneration by sustained delivery of vascular endothelial growth factor.

    Science.gov (United States)

    Xiong, Qianwei; Lin, Houwei; Hua, Xiaolin; Liu, Li; Sun, Ping; Zhao, Zhen; Shen, Xiaowei; Cui, Daxiang; Xu, Maosheng; Chen, Fang; Geng, Hongquan

    2015-01-01

    Macroscopic evidence of contracture has been identified as a major issue during the regeneration process. We hypothesize that lack of angiogenesis is the primary cause of contracture and explore a nanomedicine approach to achieve sustained release of vascular endothelial growth factor (VEGF) to stimulate angiogenesis. We evaluate the efficacy of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for long-term (3 months) sustained release of VEGF in bladder acellular matrix allografts (BAMA) in a swine model. We anticipate that the sustained release of VEGF could stimulate angiogenesis along the regeneration process and thereby inhibit contracture. Bladder was replaced with BAMA (5×5 cm), modified with PLGA NPs encapsulated with VEGF in a pig model. The time points chosen for sampling were 1, 2, 4, and 12 weeks. The regenerated areas were then measured to obtain the contracture rate, and the extent of revascularization was calculated using histological and morphological features. In the control group of animals, the bladder was replaced with only BAMA. The in vivo release of VEGF was evident for ∼3 months, achieving the goal of long-acting sustained release, and successfully promoted the regeneration of blood vessels and smooth muscle fibers. In addition, less collagen deposition was observed in the experimental group compared with control. Most importantly, the inhibition of contracture was highly significant, and the ultimate contracture rate decreased by ∼57% in the experimental group compared with control. In isolated strips analysis, there were no significant differences between BAMA-regenerated (either VEGF added or not) and autogenous bladder. BAMA modified with VEGF-loaded PLGA-NPs can sustainably release VEGF in vivo (>3 months) to stimulate angiogenesis leading to the inhibition of contracture. This is the first study to report a viable nanomedicine-based strategy to overcome contracture during bladder regeneration induced by BAMA. Furthermore

  1. Carbohydrate administration during a day of sustained aerobic activity improves vigilance, as assessed by a novel ambulatory monitoring device, and mood

    National Research Council Canada - National Science Library

    Lieberman, Harris R; Falco, Christina M; Slade, Steven S

    2002-01-01

    .... The brain's utilization of glucose also increases during aerobic exercise. However, the effects of energy supplementation on cognitive function during sustained aerobic exercise are not well characterized...

  2. Automated analysis of images acquired with electronic portal imaging device during delivery of quality assurance plans for inversely optimized arc therapy

    DEFF Research Database (Denmark)

    Fredh, Anna; Korreman, Stine; Rosenschöld, Per Munck af

    2010-01-01

    This work presents an automated method for comprehensively analyzing EPID images acquired for quality assurance of RapidArc treatment delivery. In-house-developed software has been used for the analysis and long-term results from measurements on three linacs are presented....

  3. Formulation and Characterization of Sustained Release Floating ...

    African Journals Online (AJOL)

    Conclusion: Microballoons is a potential suitable delivery system for sustained release of metformin hydrochloride with improved bioavailability when compared with conventional dosage forms of the drug. Keywords: Gastroretentive drug delivery system (GDDS), Solvent evaporation and diffusion method, Higuchi, ...

  4. The feasibility of using a portable xenon delivery device to permit earlier xenon ventilation with therapeutic cooling of neonates during ambulance retrieval.

    Science.gov (United States)

    Dingley, John; Liu, Xun; Gill, Hannah; Smit, Elisa; Sabir, Hemmen; Tooley, James; Chakkarapani, Ela; Windsor, David; Thoresen, Marianne

    2015-06-01

    Therapeutic hypothermia is the standard of care after perinatal asphyxia. Preclinical studies show 50% xenon improves outcome, if started early. During a 32-patient study randomized between hypothermia only and hypothermia with xenon, 5 neonates were given xenon during retrieval using a closed-circuit incubator-mounted system. Without xenon availability during retrieval, 50% of eligible infants exceeded the 5-hour treatment window. With the transportable system, 100% were recruited. Xenon delivery lasted 55 to 120 minutes, using 174 mL/h (117.5-193.2) (median [interquartile range]), after circuit priming (1300 mL). Xenon delivery during ambulance retrieval was feasible, reduced starting delays, and used very little gas.

  5. Method and devices for performing stereotactic microbeam radiation therapy

    Science.gov (United States)

    Dilmanian, F. Avraham

    2010-01-05

    A radiation delivery system generally includes either a synchrotron source or a support frame and a plurality of microbeam delivery devices supported on the support frame, both to deliver a beam in a hemispherical arrangement. Each of the microbeam delivery devices or synchrotron irradiation ports is adapted to deliver at least one microbeam of radiation along a microbeam delivery axis, wherein the microbeam delivery axes of the plurality of microbeam delivery devices cross within a common target volume.

  6. Use of natural plant exudates (Sanguis Draxonis) for sustained oral insulin delivery with dramatic reduction of glycemic effects in diabetic rats.

    Science.gov (United States)

    Zhenqing, Hou; Zhenxi, Zhang; Chuanxin, Zhang; Mei, Huang

    2004-07-07

    Sanguis Draxonis (SD), a kind of natural plant exudates, has been prescribed for handling diabetic disorders as a Chinese traditional herb. Surprisingly, SD was found to be a good material for oral insulin delivery. The Insulin-loaded Sanguis Draxonis nanocapsules (ISDN) were prepared by deposition technique. The average size and width of distribution of ISDN were 184+/-24 and 110+/-16 nm, respectively. The insulin encapsulation efficiency of ISDN reached up to 69.6+/-5.6%. In vitro the release profile of insulin from ISDN can be well modeled using an exponential function [Y=1-exp(-0.0275t)], showing that there was no initial burst release of insulin. The stability studies indicated that the majority of initial amount of insulin in ISDN was preserved not only after incubation of ISDN in three kinds of proteolytic enzyme solutions at 37 degrees C for 30 min, but also after its storage at 25 degrees C for 6 months. After a single oral administration of ISDN at the dose of 25, 50, and 75 IU/kg in STZ-induced diabetic rats, the blood glucose level was depressed to 60.5+/-2.7%, 52.6+/-2.3% and 47.3+/-3.1% of the initial value at time point 8 h, respectively, and these marked decreases lasted 2-4 days. When 125I-labeled ISDN was administered orally, the distribution sequence of isotope intensity of 125I radioactivity in rat organs was as follows: liver, kidney, heart, spleen and lung. In addition, 125I radioactivity disappeared progressively as a function of time, parallel to the biological effect. In conclusion, the results demonstrate that ISDN elicits a long-term hypoglycemic effect significantly after oral administration in STZ-induced diabetic rats and it can be considered as a stable and effective system for oral insulin delivery.

  7. Integrating evidence into policy and sustainable disability services delivery in western New South Wales, Australia: the 'wobbly hub and double spokes' project

    Directory of Open Access Journals (Sweden)

    Veitch Craig

    2012-03-01

    Full Text Available Abstract Background Policy that supports rural allied health service delivery is important given the shortage of services outside of Australian metropolitan centres. The shortage of allied health professionals means that rural clinicians work long hours and have little peer or service support. Service delivery to rural and remote communities is further complicated because relatively small numbers of clients are dispersed over large geographic areas. The aim of this five-year multi-stage project is to generate evidence to confirm and develop evidence-based policies and to evaluate their implementation in procedures that allow a regional allied health workforce to more expeditiously respond to disability service need in regional New South Wales, Australia. Methods/Design The project consists of four inter-related stages that together constitute a full policy cycle. It uses mixed quantitative and qualitative methods, guided by key policy concerns such as: access, complexity, cost, distribution of benefits, timeliness, effectiveness, equity, policy consistency, and community and political acceptability. Stage 1 adopts a policy analysis approach in which existing relevant policies and related documentation will be collected and reviewed. Policy-makers and senior managers within the region and in central offices will be interviewed about issues that influence policy development and implementation. Stage 2 uses a mixed methods approach to collecting information from allied health professionals, clients, and carers. Focus groups and interviews will explore issues related to providing and receiving allied health services. Discrete Choice Experiments will elicit staff and client/carer preferences. Stage 3 synthesises Stage 1 and 2 findings with reference to the key policy issues to develop and implement policies and procedures to establish several innovative regional workforce and service provision projects. Stage 4 uses mixed methods to monitor and

  8. Sustained delivery of bioactive TGF-β1 from self-assembling peptide hydrogels induces chondrogenesis of encapsulated bone marrow stromal cells

    Science.gov (United States)

    Kopesky, Paul W.; Byun, Sangwon; Vanderploeg, Eric J.; Kisiday, John D.; Frisbie, David D.; Grodzinsky, Alan J.

    2013-01-01

    Tissue engineering strategies for cartilage defect repair require technology for local targeted delivery of chondrogenic and anti-inflammatory factors. The objective of this study was to determine the release kinetics of transforming growth factor β1 (TGF-β1) from self-assembling peptide hydrogels, a candidate scaffold for cell transplant therapies, and stimulate chondrogenesis of encapsulated young equine bone marrow stromal cells (BMSCs). Although both peptide and agarose hydrogels retained TGF-β1, 5-fold higher retention was found in peptide. Excess unlabeled TGF-β1 minimally displaced retained radiolabeled TGF-β1, demonstrating biologically relevant loading capacity for peptide hydrogels. The initial release from acellular peptide hydrogels was nearly 3-fold lower than agarose hydrogels, at 18% of loaded TGF-β1 through 3 days as compared to 48% for agarose. At day 21, cumulative release of TGF-β1 was 32–44% from acellular peptide hydrogels, but was 62% from peptide hydrogels with encapsulated BMSCs, likely due to cell-mediated TGF-β1 degradation and release of small labeled species. TGF-β1 loaded peptide hydrogels stimulated chondrogenesis of young equine BMSCs, a relevant preclinical model for treating injuries in young human cohorts. Self-assembling peptide hydrogels can be used to deliver chondrogenic factors to encapsulated cells making them a promising technology for in vivo, cell-based regenerative medicine. PMID:23650117

  9. The Sustained Delivery of Resveratrol or a Defined Grape Powder Inhibits New Blood Vessel Formation in a Mouse Model of Choroidal Neovascularization

    Science.gov (United States)

    Kanavi, Mozhgan Rezaie; Darjatmoko, Soesiawati; Wang, Shoujian; Azari, Amir A.; Farnoodian, Mitra; Kenealey, Jason D.; van Ginkel, Paul R.; Albert, Daniel M.; Sheibani, Nader; Polans, Arthur S.

    2015-01-01

    The objective of this study was to determine whether resveratrol or a defined, reconstituted grape powder can attenuate the formation of new blood vessels in a mouse model of choroidal neovascularization (CNV). To accomplish this objective, C57BL/6J mice were randomized into control or treatment groups which received either resveratrol or grape powder by daily oral gavage, resveratrol or grape powder delivered ad libitum through the drinking water, or resveratrol by slow release via implanted osmotic pumps. A laser was used to rupture Bruch’s membrane to induce CNV which was then detected in sclerochoroidal eyecups stained with antibodies against intercellular adhesion molecule-2. CNV area was measured using fluorescence microscopy and Image J software. Ad libitum delivery of both resveratrol and grape powder was shown to significantly reduce the extent of CNV by 68% and 57%, respectively. Parallel experiments conducted in vitro demonstrated that resveratrol activates p53 and inactivates Akt/protein kinase B in choroidal endothelial cells, contributing to its anti-proliferative and anti-migratory properties. In addition resveratrol was shown to inhibit the formation of endothelial cell networks, augmenting its overall anti-angiogenic effects. The non-toxic nature of resveratrol makes it an especially attractive candidate for the prevention and/or treatment of CNV. PMID:25361423

  10. Sustained delivery of insulin-like growth factor-1/hepatocyte growth factor stimulates endogenous cardiac repair in the chronic infarcted pig heart.

    Science.gov (United States)

    Koudstaal, Stefan; Bastings, Maartje M C; Feyen, Dries A M; Waring, Cheryl D; van Slochteren, Frebus J; Dankers, Patricia Y W; Torella, Daniele; Sluijter, Joost P G; Nadal-Ginard, Bernardo; Doevendans, Pieter A; Ellison, Georgina M; Chamuleau, Steven A J

    2014-03-01

    Activation of endogenous cardiac stem/progenitor cells (eCSCs) can improve cardiac repair after acute myocardial infarction. We studied whether the in situ activation of eCSCs by insulin-like growth factor 1 (IGF-1) and hepatocyte growth factor (HGF) could be increased using a newly developed hydrogel in chronic myocardial infarction (MI). One-month post-MI pigs underwent NOGA-guided intramyocardial injections of IGF-1/HGF (GF: both 0.5 μg/mL, n = 5) or IGF-1/HGF incorporated in UPy hydrogel (UPy-GF; both 0.5 μg/mL, n = 5). UPy hydrogel without added growth factors was administered to four control (CTRL) pigs. Left ventricular ejection fraction was increased in the UPy-GF and GF animals compared to CTRLs. UPy-GF delivery reduced pathological hypertrophy, led to the formation of new, small cardiomyocytes, and increased capillarization. The eCSC population was increased almost fourfold in the border zone of the UPy-GF-treated hearts compared to CTRL hearts. These results show that IGF-1/HGF therapy led to an improved cardiac function in chronic MI and that effect size could be further increased by using UPy hydrogel.

  11. The Sustained Delivery of Resveratrol or a Defined Grape Powder Inhibits New Blood Vessel Formation in a Mouse Model of Choroidal Neovascularization

    Directory of Open Access Journals (Sweden)

    Mozhgan Rezaie Kanavi

    2014-10-01

    Full Text Available The objective of this study was to determine whether resveratrol or a defined, reconstituted grape powder can attenuate the formation of new blood vessels in a mouse model of choroidal neovascularization (CNV. To accomplish this objective, C57BL/6J mice were randomized into control or treatment groups which received either resveratrol or grape powder by daily oral gavage, resveratrol or grape powder delivered ad libitum through the drinking water, or resveratrol by slow release via implanted osmotic pumps. A laser was used to rupture Bruch’s membrane to induce CNV which was then detected in sclerochoroidal eyecups stained with antibodies against intercellular adhesion molecule-2. CNV area was measured using fluorescence microscopy and Image J software. Ad libitum delivery of both resveratrol and grape powder was shown to significantly reduce the extent of CNV by 68% and 57%, respectively. Parallel experiments conducted in vitro demonstrated that resveratrol activates p53 and inactivates Akt/protein kinase B in choroidal endothelial cells, contributing to its anti-proliferative and anti-migratory properties. In addition resveratrol was shown to inhibit the formation of endothelial cell networks, augmenting its overall anti-angiogenic effects. The non-toxic nature of resveratrol makes it an especially attractive candidate for the prevention and/or treatment of CNV.

  12. Nanocapsules based on linear and Y-shaped 3-miktoarm star-block PEO-PCL copolymers as sustained delivery system for hydrophilic molecules.

    Science.gov (United States)

    Maglio, Giovanni; Nicodemi, Fabio; Conte, Claudia; Palumbo, Rosario; Tirino, Pasquale; Panza, Elisabetta; Ianaro, Angela; Ungaro, Francesca; Quaglia, Fabiana

    2011-12-12

    Well-defined amphiphilic Y-shaped miktoarm star-block copolymers of PEO and PCL were synthesized by ring-opening polymerization of ε-caprolactone initiated by a PEO-bound lysine macroinitiator. The copolymers were characterized by (1)H NMR, SEC, DSC, and WAXD techniques. Separate PCL and PEO crystalline phases occur in melt-crystallized copolymers when their segmental lengths were comparable and the PCL content was ≤80 wt %. Self-assembling of these copolymers in aqueous medium led to nanoaggregates with low critical aggregation concentration values (0.35 to 1.6 mg·L(-1)) and size depending on composition. Despite the fact that copolymers were not prone to self-organize in vesicles, once processed by a novel w/o emulsion-melting-sonication technique, they gave nanocapsules with a water core and a hydrophilic surface. A macromolecular fluorescent dye was effectively loaded and released at sustained rate by optimizing nanocapsule formulation. The results demonstrate that amphiphilic block copolymers can be assembled in different kinds of nanomorphologies independently of their hydrophilic/hydrophobic balance and architecture through specifically designed preparation techniques.

  13. Use of rotary fluidized-bed technology for development of sustained-release plant extracts pellets: potential application for feed additive delivery.

    Science.gov (United States)

    Meunier, J-P; Cardot, J-M; Gauthier, P; Beyssac, E; Alric, M

    2006-07-01

    The aim of this study was to develop sustained release plant extracts as a potential alternative to antibiotic growth promoters for growing pigs. Pellets with a core based on microcrystalline cellulose and 3 active compounds (eugenol, carvacrol, and thymol) were prepared using rotary fluidized-bed technology. Two particle sizes were produced that had a mean size of approximately 250 and 500 mum. Results show the process was able to produce pellets with a spherical and homogenous form when 10% of the active compounds were incorporated into the core. When active compounds were increased to 20%, the pellet became stickier, and the yield decreased from 90 to 65%. Different amounts of coating in the form of an aqueous-based ethylcellulose (EC) dispersion (Surelease) were applied to the core to modify the release of active compounds. The efficacy of the coating was evaluated in vitro using a flow-through cell apparatus. The time to achieve 50 and 90% dissolution increased with the increase in particle size (P eugenol was always faster than for thymol or carvacrol. The close monitoring of plant extract behavior in the gastrointestinal tract could become a key factor in the continued use of phyto-molecules as alternatives to antibiotic growth promoters and in optimizing the balance between cost and efficacy. Different microencapsulation technologies can be used, of which the rotary fluidized bed warrants consideration because of the quality of the products obtained.

  14. In Vitro Sustained Release Study of Gallic Acid Coated with Magnetite-PEG and Magnetite-PVA for Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Dena Dorniani

    2014-01-01

    Full Text Available The efficacy of two nanocarriers polyethylene glycol and polyvinyl alcohol magnetic nanoparticles coated with gallic acid (GA was accomplished via X-ray diffraction, infrared spectroscopy, magnetic measurements, thermal analysis, and TEM. X-ray diffraction and TEM results showed that Fe3O4 nanoparticles were pure iron oxide having spherical shape with the average diameter of 9 nm, compared with 31 nm and 35 nm after coating with polyethylene glycol-GA (FPEGG and polyvinyl alcohol-GA (FPVAG, respectively. Thermogravimetric analyses proved that after coating the thermal stability was markedly enhanced. Magnetic measurements and Fourier transform infrared (FTIR revealed that superparamagnetic iron oxide nanoparticles could be successfully coated with two polymers (PEG and PVA and gallic acid as an active drug. Release behavior of gallic acid from two nanocomposites showed that FPEGG and FPVAG nanocomposites were found to be sustained and governed by pseudo-second-order kinetics. Anticancer activity of the two nanocomposites shows that the FPEGG demonstrated higher anticancer effect on the breast cancer cell lines in almost all concentrations tested compared to FPVAG.

  15. Lung delivery of non-CFC salbutamol via small volume metal spacer and large volume plastic spacer devices compared with an open vent jet nebulizer.

    Science.gov (United States)

    Lipworth, B J; Clark, D J

    1998-02-01

    To compare the lung delivery of salbutamol from a commonly used constant output open vent jet nebuliser (Sidestream) with use of both a conventional large volume plastic spacer (Volumatic) and a novel small volume metal spacer (NebuChamber). This was assessed using the early lung absorption profile of salbutamol over the first 20 min after inhalation. Twelve healthy volunteers were studied in a randomized single (investigator) blind crossover design. Single 1200 microg nominal doses salbutamol from a CFC-free metered-dose inhaler (12 sequential 100 microg puffs of Airomir) were delivered via the Volumatic and NebuChamber spacers. A single 1200 microg nominal dose of salbutamol was given as a 4 ml fill volume from a Sidestream nebuliser with mouthpiece. Mouth rinsing was performed after each drug sequence. Plasma salbutamol was measured at 5, 10, 15 and 20 min after the last dose of each inhalation sequence, with calculation of maximal concentration (Cmax) and average concentration over 20 min (C[av]). Systemic beta2-responses were measured as plasma potassium, tremor and heart rate. Both the Volumatic and the NebuChamber spacers produced significantly greater salbutamol concentration than the Sidestream nebuliser. For C(av) this amounted to a 7.34-fold difference (95%CI 5.31 to 9.38) between Volumatic vs Sidestream, and a 7.04-fold difference (95%CI 4.91 to 9.17) for NebuChamber vs Sidestream. Similar differences were found for the extrapulmonary beta2-responses. There were no significant differences in either salbutamol concentration or extrapulmonary beta2-responses between the Volumatic and NebuChamber spacers. We found that, in vivo, both the Volumatic and the NebuChamber spacers produced seven-fold greater lung delivery of salbutamol than the Sidestream nebuliser when comparing microgram equivalent nominal doses, in terms of the early lung absorption profile.

  16. Hyaluronic acid-grafted PLGA nanoparticles for the sustained delivery of berberine chloride for an efficient suppression of Ehrlich ascites tumors.

    Science.gov (United States)

    Bhatnagar, Priyanka; Kumari, Manisha; Pahuja, Richa; Pant, A B; Shukla, Y; Kumar, Pradeep; Gupta, K C

    2018-02-13

    To promote the specific targeting and elimination of CD44-positive cancer cells, berberine chloride (BRB)-encapsulated hyaluronic acid-grafted poly(lactic-co-glycolic acid) copolymer (BRB-d(HA)-g-PLGA) nanoparticles (NPs) were prepared. The targeted action of these NPs was compared to non-targeted BRB-loaded PLGA NPs and bulk BRB. The in vitro studies demonstrated faster release of BRB and increased cytotoxicity of BRB-d(HA)-g-PLGA NPs in Hela and MCF-7 cells in comparison to BRB-PLGA NPs and bulk BRB. The uptake of BRB-d(HA)-g-PLGA NPs was increased in case of MCF-7 cells as compared to HeLa cells owing to the higher expression of CD44 receptors on MCF-7 cells. The CD44 receptor-mediated uptake of these NPs was confirmed through competitive inhibition experiments. The in vitro results were further validated in vivo in Ehrlich Ascites Carcinoma (EAC)-bearing mice. EAC-bearing mice were injected intravenously with these NPs and the results obtained were compared with that of BRB-PLGA NPs and bulk BRB. BRB-d(HA)-g-PLGA NPs were found to significantly enhance apoptosis, sub-G1 content, life span, mean survival time, and ROS levels in EAC cells with subsequent decrease in mitochondrial membrane potential and tumor burden ion tumor-bearing mice. Taking into account the findings of in vitro and in vivo studies, the enhanced and targeted anti-tumor activity of HA-grafted PLGA copolymer-encapsulated NPs of BRB cannot be negated. Therefore, HA-grafted nanoparticle-based delivery of BRB may offer a promising and improved alternative for anti-tumor therapy.

  17. Optimization of a polymer composite employing molecular mechanic simulations and artificial neural networks for a novel intravaginal bioadhesive drug delivery device.

    Science.gov (United States)

    Ndesendo, Valence M K; Pillay, Viness; Choonara, Yahya E; du Toit, Lisa C; Kumar, Pradeep; Buchmann, Eckhart; Meyer, Leith C R; Khan, Riaz A

    2012-01-01

    This study aimed at elucidating an optimal synergistic polymer composite for achieving a desirable molecular bioadhesivity and Matrix Erosion of a bioactive-loaded Intravaginal Bioadhesive Polymeric Device (IBPD) employing Molecular Mechanic Simulations and Artificial Neural Networks (ANN). Fifteen lead caplet-shaped devices were formulated by direct compression with the model bioactives zidovudine and polystyrene sulfonate. The Matrix Erosion was analyzed in simulated vaginal fluid to assess the critical integrity. Blueprinting the molecular mechanics of bioadhesion between vaginal epithelial glycoprotein (EGP), mucin (MUC) and the IBPD were performed on HyperChem 8.0.8 software (MM+ and AMBER force fields) for the quantification and characterization of correlative molecular interactions during molecular bioadhesion. Results proved that the IBPD bioadhesivity was pivoted on the conformation, orientation, and poly(acrylic acid) (PAA) composition that interacted with EGP and MUC present on the vaginal epithelium due to heterogeneous surface residue distributions (free energy= -46.33 kcalmol(-1)). ANN sensitivity testing as a connectionist model enabled strategic polymer selection for developing an IBPD with an optimally prolonged Matrix Erosion and superior molecular bioadhesivity (ME = 1.21-7.68%; BHN = 2.687-4.981 N/mm(2)). Molecular modeling aptly supported the EGP-MUC-PAA molecular interaction at the vaginal epithelium confirming the role of PAA in bioadhesion of the IBPD once inserted into the posterior fornix of the vagina.

  18. Age and gender considerations for technology-assisted delivery of therapy for substance use disorder treatment: A patient survey of access to electronic devices.

    Science.gov (United States)

    Antoine, Denis; Heffernan, Sean; Chaudhry, Amina; King, Van; Strain, Eric C

    2016-12-01

    Technology-assisted treatment (TAT) can be an effective supplement to established face-to-face therapy modalities with a growing literature in substance use disorder (SUD) treatment. TAT access, interest, and familiarity are potential limitations to the use and efficacy of these approaches to treatment. 174 participants in outpatient SUD treatment were administered a survey regarding technology device and Internet access, and interest in engaging in TAT SUD counseling (SUDC). The group was dichotomized by mean age and gender to examine potential variations in in these subgroups. Forty-three (43%) of participants were female, and the mean age was 44.8 years, and 89% of participants had Internet access. 83% of participants were interested in TAT for SUD counseling; 81% expected it to be at least "moderately helpful." 34% of participants noted they would choose to continue face-to-face therapy exclusively. 91% of participants had cell phones, but only 50% could access data or the Internet via their handheld device. 80% of participants stated they would be interested in trying SUDC via their phone. Women had a higher preference for computer-based SUDC than men, with gender being significantly correlated with TAT perceive helpfulness. These findings suggest that patients in outpatient SUD treatment have access to resources for TAT implementation, although access was not always readily available. Future research will be needed to determine whether the technology that this population possesses will be able to support the evolving TAT modalities and whether interest in TAT across age and gender groups equalizes over time.

  19. Iontophoretically enhanced ciclopirox delivery into and across human nail plate.

    Science.gov (United States)

    Hao, Jinsong; Smith, Kelly A; Li, S Kevin

    2009-10-01

    Transungual delivery of antifungal drugs is hindered by the low permeability of human nail plates, and as such, repeated dosing over a long period of time is necessary for effective treatment. The objectives of this study were to explore the possibilities of (a) enhancing the delivery of ciclopirox (CIC) across human nail plates and (b) sustaining CIC delivery from the larger resultant drug depot in the nail plates with constant voltage iontophoresis. In vitro passive and 9 V cathodal iontophoretic transport experiments of CIC across human nails were performed. Transungual CIC delivery with Penlac was the control. The amounts of CIC released from and deposited in the nails were determined in drug release and extraction experiments, respectively. Iontophoresis increased the flux of CIC permeated across the nail approximately 10 times compared to passive delivery from the same formulation or from Penlac. A significant amount of CIC was loaded into and released from the nails; the CIC concentrations were estimated to be above the minimum inhibitory concentrations of CIC for dermatophytic molds. The apparent transport lag time decreased in iontophoretic transport. The results demonstrate that iontophoresis was able to deliver an effective amount of CIC into and across the nails, and this suggests the feasibility of a constant voltage battery-powered transungual iontophoretic device.

  20. A Randomized Trial to Evaluate the Sustained Efficacy of a Mucus Clearance Device in Ambulatory Patients with Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Norman Wolkove

    2004-01-01

    Full Text Available OBJECTIVE: To determine whether a mucus clearance device (MCD (Flutter; Axcan Scandipharm, USA could consistently improve the bronchodilator response and exercise performance in patients with chronic obstructive pulmonary disease (COPD when used in an ambulatory setting over a one-week period.

  1. Psyllium and copolymers of 2-hydroxylethylmethacrylate and acrylamide-based novel devices for the use in colon specific antibiotic drug delivery.

    Science.gov (United States)

    Singh, Baljit; Chauhan, Nirmala; Kumar, S; Bala, Ritu

    2008-03-20

    In order to utilize the psyllium husk, a medicinally important natural polysaccharide, to develop the hydrogels meant for the drug delivery, we have prepared psyllium 2-hydroxylethylmethacrylate (HEMA) and acrylamide (AAm)-based polymeric networks by using N,N'-methylenebisacrylamide (N,N'-MBAAm) as crosslinker and ammonium persulfate (APS) as initiator. The polymeric networks thus formed [psy-cl-poly(HEMA-co-AAm)] were characterized with FTIR and swelling studies which were carried out as a function of crosslinker concentration, time, pH and [NaCl] of the swelling medium. The swelling kinetics of the hydrogels and in vitro release dynamics of model drug (tetracycline hydrochloride) from these hydrogels has been studied for the evaluation of swelling mechanism and drug release mechanism from the hydrogels. The values of the diffusion exponent 'n' have been obtained 0.5 for both swelling kinetics and drug release dynamics. This value shows that the Fickian type diffusion mechanism has occurred for the swelling of the polymers and for the release of drug from the polymers in different release mediums. The values of the initial diffusion coefficients (10.6 x 10(-4), 13.1 x 10(-4), 14.0 x 10(-4))cm(2)/min, average diffusion coefficients (22.2 x 10(-4), 25.7 x 10(-4), 27.0 x 10(-4))cm(2)/min and late diffusion coefficients (1.68 x 10(-4), 2.15 x 10(-4), 2.28 x 10(-4))cm(2)/min for the release of tetracycline HCl respectively in distilled water, pH 2.2 buffer and pH 7.4 buffer from the drug loaded samples shows that in the initial stages, the rate of release of drug from the hydrogels is slow and rate of diffusion of drug increases with time.

  2. Treatment of corneal defects with delayed re-epithelization with a medical device/drug delivery system for epidermal growth factor.

    Science.gov (United States)

    Holland, Simon; Morck, Douglas; Schultz, Clyde

    2012-01-01

      Human recombinant epidermal growth factor has been shown to be effective in corneal healing when applied topically. The purpose of this preliminary study was to observe whether re-epithelization occurred in patients with non-healing corneal defects treated with a bandage contact lenses impregnated with epidermal growth factor.   Prospective non-comparative interventional case series study. Epidermal growth factor-impregnated bandage contact lenses (created through passive transfer of epidermal growth factor into hydrogel contact lenses of high water content) were used to passively release epidermal growth factor to the corneal surface of the damaged eye.   Nine clinical patients who presented for tertiary care at the University of British Columbia Eye Care Centre at Vancouver General Hospital.   All patients had clinically significant delayed corneal re-epithelization that had not healed despite standard treatments including conventional bandage contact lenses and topical medications. Causes of delayed re-epithelization varied from corneal injuries (e.g. alkali burns, recurrent corneal erosions) to recent corneal surgery (photorefractive keratectomy, phototherapeutic keratectomy, penetrating keratoplasty).   Closure of wounds.   Re-epithelialization was seen in the corneas of seven of the nine patients within 8 days after insertion of the epidermal growth factor-treated bandage contact lens into the damaged eye. The drug delivery system appeared to be most effective in non-inflamed corneas.   Preliminary results indicate that bandage contact lenses impregnated with epidermal growth factor may be helpful in promoting re-epithelization in corneas with delayed healing. Efficacy appears to be reduced for vascularized and significantly inflamed corneas. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

  3. ICT innovations for sustainability

    CERN Document Server

    Aebischer, Bernard

    2015-01-01

    ICT Innovations for Sustainability is an investigation of how information and communication technology can contribute to sustainable development. It presents clear definitions of sustainability, suggesting conceptual frameworks for the positive and negative effects of ICT on sustainable development. It reviews methods of assessing the direct and indirect impact of ICT systems on energy and materials demand, and examines the results of such assessments. In addition, it investigates ICT-based approaches to supporting sustainable patterns of production and consumption, analyzing them at various levels of abstraction – from end-user devices, Internet infrastructure, user behavior, and social practices to macro-economic indicators.   Combining approaches from Computer Science, Information Systems, Human-Computer Interaction, Economics, and Environmental Sciences, the book presents a new, holistic perspective on ICT for Sustainability (ICT4S). It is an indispensable resource for anyone working in the area of ICT...

  4. Obstetrical trauma to the genital tract following vaginal delivery

    National Research Council Canada - National Science Library

    Khaskheli, Meharunnissa; Baloch, Shahla; Baloch, Aneela Sheeba

    2012-01-01

    .... All women who sustained genital tract trauma during delivery at the study centre and those referred from periphery with the same condition within 40 days of delivery were enrolled in the study...

  5. Rationale and Safety Assessment of a Novel Intravaginal Drug-Delivery System with Sustained DL-Lactic Acid Release, Intended for Long-Term Protection of the Vaginal Microbiome.

    Directory of Open Access Journals (Sweden)

    Hans Verstraelen

    Full Text Available Bacterial vaginosis is a prevalent state of dysbiosis of the vaginal microbiota with wide-ranging impact on human reproductive health. Based on recent insights in community ecology of the vaginal microbiome, we hypothesize that sustained vaginal DL-lactic acid enrichment will enhance the recruitment of lactobacilli, while counteracting bacterial vaginosis-associated bacteria. We therefore aimed to develop an intravaginal device that would be easy to insert and remove, while providing sustained DL-lactic acid release into the vaginal lumen. The final prototype selected is a vaginal ring matrix system consisting of a mixture of ethylene vinyl acetate and methacrylic acid-methyl methacrylate copolymer loaded with 150 mg DL-lactic acid with an L/D-lactic acid ratio of 1:1. Preclinical safety assessment was performed by use of the Slug Mucosal Irritation test, a non-vertebrate assay to evaluate vaginal mucosal irritation, which revealed no irritation. Clinical safety was evaluated in a phase I trial with six healthy nulliparous premenopausal volunteering women, with the investigational drug left in place for 7 days. Colposcopic monitoring according to the WHO/CONRAD guidelines for the evaluation of vaginal products, revealed no visible cervicovaginal mucosal changes. No adverse events related to the investigational product occurred. Total release from the intravaginal ring over 7 days was estimated through high performance liquid chromatography at 37.1 (standard deviation 0.9 mg DL-lactic acid. Semisolid lactic acid formulations have been studied to a limited extent in the past and typically consist of a large volume of excipients and very high doses of lactic acid, which is of major concern to mucosal safety. We have documented the feasability of enriching the vaginal environment with pure DL-lactic acid with a prototype intravaginal ring. Though the efficacy of this platform remains to be established possibly requiring further development, this

  6. Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process.

    Science.gov (United States)

    Swain, Basudev; Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo; Lee, Kun-Jae

    2015-07-01

    Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga0.97N0.9O0.09 is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga0.97N0.9O0.09 of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4M HCl, 100°C and pulp density of 100 kg/m(3,) respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Applications of mesoporous materials as excipients for innovative drug delivery and formulation.

    Science.gov (United States)

    Shen, Shou-Cang; Ng, Wai Kiong; Chia, Leonard Sze Onn; Dong, Yuan-Cai; Tan, Reginald Beng Hee

    2013-01-01

    Due to uniquely ordered nanoporous structure and high surface area as well as large pore volume, mesoporous materials have exhibited excellent performance in both controlled drug delivery with sustained release profiles and formulation of poorly aqueoussoluble drugs with enhanced bioavailability. Compared with other bulk excipients, mesoporous materials could achieve a higher loading of active ingredients and a tunable drug release profile, as the high surface density of surface hydroxyl groups offered versatility to be functionalized. With drug molecules stored in nano sized channels, the pore openings could be modified using functional polymers or nano-valves performing as stimuli-responsive release devices and the drug release could be triggered by environmental changes or other external effects. In particular, mesoporous silica nanoparticles (MSN) have attracted much attention for application in functional target drug delivery to the cancer cell. The smart nano-vehicles for drug delivery have showed obvious improvements in the therapeutic efficacy for tumor suppression as compared with conventional sustained release systems, although further progress is still needed for eventual clinical applications. Alternatively, unmodified mesoporous silica also exhibited feasible application for direct formulation of poorly water-soluble drugs to enhance dissolution rate, solubility and thus increase the bioavailability after administration. In summary, mesoporous materials offer great versatility that can be used both for on-demand oral and local drug delivery, and scientists are making great efforts to design and fabricate innovative drug delivery systems based on mesoporous drug carriers.

  8. Sustained delivery of propranolol by using multiparticulate ...

    African Journals Online (AJOL)

    METHODS: A formulation was prepared without using mineral oil by conventional ionotropic gelation method. All other formulations of oil entrapped floating gel beads of propranolol hydrochloride were prepared by using emulsion gelation method in which sodium alginate was used as a gelling agent and mineral oil was ...

  9. Concanavalin A conjugated biodegradable nanoparticles for oral insulin delivery

    Energy Technology Data Exchange (ETDEWEB)

    Hurkat, Pooja; Jain, Aviral; Jain, Ashish; Shilpi, Satish; Gulbake, Arvind; Jain, Sanjay K., E-mail: drskjainin@yahoo.com [Dr. Hari Singh Gour Vishwavidyalaya, Pharmaceutics Research Projects Laboratory, Department of Pharmaceutical Sciences (India)

    2012-11-15

    Major research issues in oral protein delivery include the stabilization of protein in delivery devices which could increase its oral bioavailability. The study deals with development of oral insulin delivery system utilizing biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and modifying its surface with Concanavalin A to increase lymphatic uptake. Surface-modified PLGA nanoparticles were characterized for conjugation efficiency of ligand, shape and surface morphology, particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro drug release. Stability of insulin in the developed formulation was confirmed by SDS-PAGE, and integrity of entrapped insulin was assessed using circular dichroism spectrum. Ex vivo study was performed on Wistar rats, which exhibited the higher intestinal uptake of Con A conjugated nanoparticles. In vivo study performed on streptozotocin-induced diabetic rats which indicate that a surface-modified nanoparticle reduces blood glucose level effectively within 4 h of its oral administration. In conclusion, the present work resulted in successful production of Con A NPs bearing insulin with sustained release profile, and better absorption and stability. The Con A NPs showed high insulin uptake, due to its relative high affinity for non-reducing carbohydrate residues i.e., fucose present on M cells and have the potential for oral insulin delivery in effective management of Type 1 diabetes condition.

  10. Concanavalin A conjugated biodegradable nanoparticles for oral insulin delivery

    Science.gov (United States)

    Hurkat, Pooja; Jain, Aviral; Jain, Ashish; Shilpi, Satish; Gulbake, Arvind; Jain, Sanjay K.

    2012-11-01

    Major research issues in oral protein delivery include the stabilization of protein in delivery devices which could increase its oral bioavailability. The study deals with development of oral insulin delivery system utilizing biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and modifying its surface with Concanavalin A to increase lymphatic uptake. Surface-modified PLGA nanoparticles were characterized for conjugation efficiency of ligand, shape and surface morphology, particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro drug release. Stability of insulin in the developed formulation was confirmed by SDS-PAGE, and integrity of entrapped insulin was assessed using circular dichroism spectrum. Ex vivo study was performed on Wistar rats, which exhibited the higher intestinal uptake of Con A conjugated nanoparticles. In vivo study performed on streptozotocin-induced diabetic rats which indicate that a surface-modified nanoparticle reduces blood glucose level effectively within 4 h of its oral administration. In conclusion, the present work resulted in successful production of Con A NPs bearing insulin with sustained release profile, and better absorption and stability. The Con A NPs showed high insulin uptake, due to its relative high affinity for non-reducing carbohydrate residues i.e., fucose present on M cells and have the potential for oral insulin delivery in effective management of Type 1 diabetes condition.

  11. Effect of zein on biodegradable inserts for the delivery of tetracycline within periodontal pockets.

    Science.gov (United States)

    de Sousa, Fábio Oliveira; Blanco-Méndez, Jose; Pérez-Estévez, Antonio; Seoane-Prado, Rafael; Luzardo-Álvarez, Asteria

    2012-08-01

    Treatment with antibiotics within the periodontal pocket against bacterial infections represents a useful and adjunctive tool to conventional therapy for healing and teeth preservation. With this function in view, an implantable, tetracycline delivery device for the treatment of periodontal disease was developed. The aim of this study was to develop biodegradable, tetracycline-loaded microparticles made of two polymers: PLGA and zein which were compressed into monolithic devices. In this polymer delivery system, the encapsulation efficiency, release characteristics, drug-polymer interaction, and antibacterial activity of loaded drug were investigated. The interaction of tetracycline with the corn protein zein was studied by nuclear magnetic resonance (NMR), Fourier transform infrared, and X-ray diffraction. The hydrophobic interaction of tetracycline with zein in the formulations was deduced from the NMR studies, whereas X-ray diffraction studies showed a new crystalline state of the drug in the presence of the protein. Zein was not denatured by preparation of inserts. Sustained release of tetracycline was obtained, and the proportion of zein in the inserts had a great impact on the drug release. Finally, an effective tetracycline release from inserts against Staphylococcus aureus was achieved over 30 days. In conclusion, the PLGA:zein delivery system described in this study was found to be effective in controlled delivery of tetracycline, and hence may be suitable for intra-pocket delivery of antimicrobial agents in the treatment of periodontitis.

  12. A Sustainable Engineering Solution for Pediatric Dehydration in Low-Resource Clinical Environments

    Directory of Open Access Journals (Sweden)

    Ashley R Taylor

    2016-09-01

    Full Text Available Engineering efforts in low resource environments pose a unique set of challenges, requiring an in-depth understanding of local needs, comprehensive mapping of community resources, and extensive collaboration with local expertise. The importance of these principles is demonstrated in this paper by detailing the novel design and field demonstration of an affordable, locally manufactured intravenous fluid regulation device. Collaboration with clinical personnel in Uganda and Malawi guided device design. In-country physicians emphasised the need to regulate volume of intravenous (IV fluid delivered to a paediatric patient without use of electricity. The proposed device regulates IV fluid delivery within ±20 mL of total prescribed dosage, providing a method of reducing fatalities caused by over-hydration in low resource environments; the feasibility of building the device from local resources was demonstrated by a field research team in Malawi. The device was successfully constructed entirely from local resources for a total cost of $46.21 (USD. Additionally, the device was demonstrated in rural clinics where 89 % of surveyed clinical staff reported that they would use the device to regulate IV fluid delivery. This paper emphasises the importance of collaborating with communities for community-based engineering solutions. Mapping community assets and collaborating with local expertise are crucial to success of engineering efforts. Long-term, community-based efforts are likely to sustainably improve health outcomes and strengthen economies of communities worldwide.

  13. Sustainable Food & Sustainable Economics

    OpenAIRE

    Alvarez, Mavis Dora

    2012-01-01

    Cuba today is immersed in a very intense process of perfecting its agricultural production structures with the goal of making them more efficient and sustainable in their economic administration and in their social and environmental management. Agricultural cooperatives in Cuba have the responsibility of producing on 73% of the country's farmland. Their contributions are decisive to developing agricultural production and to ensuring more and better food for the population, in addition to redu...

  14. After Delivery

    Science.gov (United States)

    ... for Association Events Messaging Tools Recruiting Advocates Local Market Planning Training Webinars News & Events Advocacy News Call ... A Listen En Español After Delivery After your baby arrives, your body begins to recover from the ...

  15. Forceps Delivery

    Science.gov (United States)

    ... 2015. Related Signs of labor Forceps delivery About Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  16. Nanochanneled Device and Related Methods

    Science.gov (United States)

    Ferrari, Mauro (Inventor); Liu, Xuewu (Inventor); Grattoni, Alessandro (Inventor); Fine, Daniel (Inventor); Goodall, Randy (Inventor); Hosali, Sharath (Inventor); Medema, Ryan (Inventor); Hudson, Lee (Inventor)

    2016-01-01

    A nanochannel delivery device and method of manufacturing and use. The nanochannel delivery device comprises an inlet, an outlet, and a nanochannel. The nanochannel may be oriented parallel to the primary plane of the nanochannel delivery device. The inlet and outlet may be in direct fluid communication with the nanochannel. Considerable advances have been made in the field oftherapeutic agent (e.g. drug) delivery technology over thelast three decades, resulting in many breakthroughs in clinicalmedicine. The creation of therapeutic agent deliverydevices that are capable of delivering therapeutic agents incontrolled ways is still a challenge. One of the majorrequirements for an implantable drug delivery device iscontrolled release of therapeutic agents, ranging from smalldrug molecules to larger biological molecules. It is particularlydesirable to achieve a continuous passive drug releaseprofile consistent with zero order kinetics whereby theconcentration of drug in the bloodstream remains constantthroughout an extended delivery period.These devices have the potential to improve therapeuticefficacy, diminish potentially life-threatening side effects,improve patient compliance, minimize the intervention ofhealthcare personnel, reduce the duration of hospital stays,and decrease the diversion of regulated drugs to abusiveuses.Nanochannel delivery devices may be used in drug deliveryproducts for the effective administration of drugs. Inaddition, nanochannel delivery devices can be used in otherapplications where controlled release of a substance overtime is needed. Embodiments of this invention comprise a nanochanneldelivery device having nanochannels within a structureconfigured to yield high mechanical strength and high flowrates. Various fabrication protocols may be used to form thenanochannel delivery device. Embodiments of the fabricateddevices feature horizontal nanochannel lay-out (e.g., thenanochannel is parallel to the primary plane of the device),high molecule

  17. Scaling service delivery in a failed state

    NARCIS (Netherlands)

    Muilerman, Sander; Vellema, Sietze

    2017-01-01

    The increased use of sustainability standards in the international trade in cocoa challenges companies to find effective modes of service delivery to large numbers of small-scale farmers. A case study of the Sustainable Tree Crops Program targeting the small-scale cocoa producers in Côte d’Ivoire

  18. Mesoporous silica nanoparticles in drug delivery and biomedical applications.

    Science.gov (United States)

    Wang, Ying; Zhao, Qinfu; Han, Ning; Bai, Ling; Li, Jia; Liu, Jia; Che, Erxi; Hu, Liang; Zhang, Qiang; Jiang, Tongying; Wang, Siling

    2015-02-01

    In the past decade, mesoporous silica nanoparticles (MSNs) with a large surface area and pore volume have attracted considerable attention for their application in drug delivery and biomedicine. In this review, we highlight the recent advances in silica-assisted drug delivery systems, including (1) MSN-based immediate/sustained drug delivery systems and (2) MSN-based controlled/targeted drug delivery systems. In addition, we summarize the biomedical applications of MSNs, including (1) MSN-based biotherapeutic agent delivery; (2) MSN-assisted bioimaging applications; and (3) MSNs as bioactive materials for tissue regeneration. This comprehensive review presents recent advances in mesoporous silica nanoparticles assisted drug delivery systems, including both immediate and sustained delivery systems as well as controlled release and targeted drug delivery systems. In addition to achieving therapeutic agent delivery, imaging applications and potential use of silica NPs in tissue regeneration are also discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Adenosine-Associated Delivery Systems

    Science.gov (United States)

    Kazemzadeh-Narbat, Mehdi; Annabi, Nasim; Tamayol, Ali; Oklu, Rahmi; Ghanem, Amyl; Khademhosseini, Ali

    2016-01-01

    Adenosine is a naturally occurring purine nucleoside in every cell. Many critical treatments such as modulating irregular heartbeat (arrhythmias), regulation of central nervous system (CNS) activity, and inhibiting seizural episodes can be carried out using adenosine. Despite the significant potential therapeutic impact of adenosine and its derivatives, the severe side effects caused by their systemic administration have significantly limited their clinical use. In addition, due to adenosine’s extremely short half-life in human blood (less than 10 s), there is an unmet need for sustained delivery systems to enhance efficacy and reduce side effects. In this paper, various adenosine delivery techniques, including encapsulation into biodegradable polymers, cell-based delivery, implantable biomaterials, and mechanical-based delivery systems, are critically reviewed and the existing challenges are highlighted. PMID:26453156

  20. In vitro and in vivo effects of PDGF-BB delivery strategies on tendon healing: a review.

    Science.gov (United States)

    Evrova, O; Buschmann, J

    2017-07-17

    To promote and support tendon healing, one viable strategy is the use or administration of growth factors at the wound/rupture site. Platelet derived growth factor-BB (PDGF-BB), together with other growth factors, is secreted by platelets after injury. PDGF-BB promotes mitogenesis and angiogenesis, which could accelerate tendon healing. Therefore, in vitro studies with PDGF-BB have been performed to determine its effect on tenocytes and tenoblasts. Moreover, accurate and sophisticated drug delivery devices, aiming for a sustained release of PDGF-BB, have been developed, either by using heparin-binding and fibrin-based matrices or different electrospinning techniques. In this review, the structure and composition, as well as the healing process of tendons, are described. Part A deals with in vitro studies. They focus on the multiple effects evoked by PDGF-BB on the cellular level. Moreover, they address strategies for the sustained delivery of PDGF-BB. Part B focuses on animal models used to test different delivery strategies for PDGF-BB, in the context of tendon reconstruction. These studies showed that dosage and timing of PDGF-BB application are the most important factors for deciding which delivery device should be applied for a specific tendon laceration.

  1. Social video content delivery

    CERN Document Server

    Wang, Zhi; Zhu, Wenwu

    2016-01-01

    This brief presents new architecture and strategies for distribution of social video content. A primary framework for socially-aware video delivery and a thorough overview of the possible approaches is provided. The book identifies the unique characteristics of socially-aware video access and social content propagation, revealing the design and integration of individual modules that are aimed at enhancing user experience in the social network context. The change in video content generation, propagation, and consumption for online social networks, has significantly challenged the traditional video delivery paradigm. Given the massive amount of user-generated content shared in online social networks, users are now engaged as active participants in the social ecosystem rather than as passive receivers of media content. This revolution is being driven further by the deep penetration of 3G/4G wireless networks and smart mobile devices that are seamlessly integrated with online social networking and media-sharing s...

  2. Sustainable agriculture

    National Research Council Canada - National Science Library

    Lichtfouse, Eric

    2009-01-01

    ... : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 Part I CLIMATE CHANGE Soils and Sustainable Agriculture: A Review : : : : : : : : : : : : : : : : : : : : : : : : : : Rattan Lal 15 Soils and Food Sufficiency...

  3. Sustainable Marketing

    NARCIS (Netherlands)

    Dam, van Y.K.

    2017-01-01

    In this article, three different conceptions of sustainable marketing are discussed and compared. These different conceptions are referred to as social, green, and critical sustainable marketing. Social sustainable marketing follows the logic of demand-driven marketing management and places the

  4. Delivery of enteral nutrition.

    Science.gov (United States)

    Grant, M J; Martin, S

    2000-11-01

    There is increasing evidence that enteral feeding is superior to parenteral nutrition with regard to maintaining gut structure and function. Selection of the enteral access route depends on the type and anticipated duration of nutrient delivery. At present, enteral feeding devices can be divided into two major categories: those entering the gastrointestinal tract through the oral or nasal cavity (oroenteric or nasoenteric tubes) and those entering through the abdominal wall including gastrostomy, duodenostomy, or jejunostomy tubes. This article provides a review of methods to insert and confirm gastric and intestinal feeding tube placement. Care of the patient with an enteric tube will be described.

  5. A Systems Approach to Nitrogen Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Goins, Bobby [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2017-10-23

    A systems based approach will be used to evaluate the nitrogen delivery process. This approach involves principles found in Lean, Reliability, Systems Thinking, and Requirements. This unique combination of principles and thought process yields a very in depth look into the system to which it is applied. By applying a systems based approach to the nitrogen delivery process there should be improvements in cycle time, efficiency, and a reduction in the required number of personnel needed to sustain the delivery process. This will in turn reduce the amount of demurrage charges that the site incurs. In addition there should be less frustration associated with the delivery process.

  6. A Systems Approach to Nitrogen Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Goins, Bobby [Y-12 National Security Complex, Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

    2017-10-17

    A systems based approach will be used to evaluate the nitrogen delivery process. This approach involves principles found in Lean, Reliability, Systems Thinking, and Requirements. This unique combination of principles and thought process yields a very in depth look into the system to which it is applied. By applying a systems based approach to the nitrogen delivery process there should be improvements in cycle time, efficiency, and a reduction in the required number of personnel needed to sustain the delivery process. This will in turn reduce the amount of demurrage charges that the site incurs. In addition there should be less frustration associated with the delivery process.

  7. Rhythmomimetic drug delivery

    CERN Document Server

    Calderer, M Carme; Siegel, Ronald A; Yao, Lingxing

    2015-01-01

    We present modeling, analysis and numerical simulation of a prototype glucose driven drug delivery device based on chemomechanical interactions and volume phase transitions in polyelectrolyte gels. The device consists of two fluid compartments, an external cell (I) mimicking the physiological environment, and a closed chamber (II), separated by a hydrogel membrane. Cell I, which is held at constant pH and ionic strength, provides a constant supply of glucose to cell II, and also serves as clearance station for reaction products. Cell II contains the drug to be delivered to the body, an enzyme that catalyzes conversion of glucose into hydrogen ions, and a piece of marble to remove excess hydrogen ions that would otherwise overwhelm the system. When the membrane is swollen, glucose flux into Cell II is high, leading to rapid production of hydrogen ions. However, the hydrogen ions are not immediately released to Cell I but react, instead, with the negatively charged carboxyl groups of the membrane, which collaps...

  8. Development of insulin delivery systems.

    Science.gov (United States)

    Siddiqui, N I; Siddiqui, Ni; Rahman, S; Nessa, A

    2008-01-01

    Delivery system of insulin is vital for its acceptance and adherence to therapy for achieving the glycemic targets. Enormous developments have occurred in the delivery system of insulin during the last twenty years and each improvement was aimed at two common goals: patients convenience and better glycemic control. Till to date, the various insulin delivery systems are: syringes/vials, injection aids, jet injectors, transmucosal delivery, transdermal delivery, external insulin infusion pump, implantable insulin pumps, insulin pens and insulin inhalers. Syringe/vial is the oldest and conventional method, still widely used and relatively cheaper. Modern plastic syringes are disposable, light weight with microfine needle for patients convenience and comfort. Oral route could be the most acceptable and viable, if the barriers can be overcome and under extensive trial. Insulin pen device is an important milestone in the delivery system of insulin as it is convenient, discrete, painless, attractive, portable with flexible life style and improved quality of life. More than 80% of European diabetic patients are using insulin pen. Future digital pen will have better memory option, blood glucose monitoring system, insulin dose calculator etc. Insulin infusion pump is a good option for the children, busy patients with flexible lifestyle and those who want to avoid multiple daily injections. Pulmonary route of insulin delivery is a promising, effective, non-invasive and acceptable alternative method. Exubera, the world first insulin inhaler was approved by FDA in 28 January 2006. But due to certain limitations, it has been withdrawn from the market in October 2007. The main concern of inhaled insulin are: long term pulmonary safety issues, cost effectiveness and user friendly device. In future, more acceptable and cost effective insulin inhaler will be introduced. Newer avenues are under extensive trial for better future insulin delivery systems.

  9. Cell-free carrier system for localized delivery of peripheral blood cell-derived engineered factor signaling: towards development of a one-step device for autologous angiogenic therapy.

    Science.gov (United States)

    Hadjipanayi, E; Bauer, A T; Moog, P; Salgin, B; Kuekrek, H; Fersch, B; Hopfner, U; Meissner, T; Schlüter, A; Ninkovic, M; Machens, H G; Schilling, A F

    2013-07-10

    Spatiotemporally-controlled delivery of hypoxia-induced angiogenic factor mixtures has been identified by this group as a promising strategy for overcoming the limited ability of chronically ischemic tissues to generate adaptive angiogenesis. We previously developed an implantable, as well as an injectable system for delivering fibroblast-produced factors in vivo. Here, we identify peripheral blood cells (PBCs) as the ideal factor-providing candidates, due to their autologous nature, ease of harvest and ample supply, and investigate wound-simulating biochemical and biophysical environmental parameters that can be controlled to optimize PBC angiogenic activity. It was found that hypoxia (3% O₂) significantly affected the expression of a range of angiogenesis-related factors including VEGF, angiogenin and thrombospondin-1, relative to the normoxic baseline. While all three factors underwent down-regulation over time under hypoxia, there was significant variation in the temporal profile of their expression. VEGF expression was also found to be dependent on cell-scaffold material composition, with fibrin stimulating production the most, followed by collagen and polystyrene. Cell-scaffold matrix stiffness was an additional important factor, as shown by higher VEGF protein levels when PBCs were cultured on stiff vs. compliant collagen hydrogel scaffolds. Engineered PBC-derived factor mixtures could be harvested within cell-free gel and microsphere carriers. The angiogenic effectiveness of factor-loaded carriers could be demonstrated by the ability of their releasates to induce endothelial cell tubule formation and directional migration in in vitro Matrigel assays, and microvessel sprouting in the aortic ring assay. To aid the clinical translation of this approach, we propose a device design that integrates this system, and enables one-step harvesting and delivering of angiogenic factor protein mixtures from autologous peripheral blood. This will facilitate the

  10. Understanding medical device regulation.

    Science.gov (United States)

    Galgon, Richard E

    2016-12-01

    The purpose of this article is to provide a structural and functional understanding of the systems used for the regulation of medical devices in the USA and European Union (EU). Safe and effective anesthesia care depends heavily on medical devices, including simple, low risk devices to complex life-supporting and life-sustaining devices. In the USA and EU, the Food and Drug Administration and European Commission, respectively, provide regulatory oversight to ensure medical devices are reasonably safe and effective when used for their intended purposes. Unfortunately, practicing anesthesiologists generally have little or no understanding of how medical devices are regulated, nor do they have sufficient knowledge of available adverse event reporting systems. The US and EU medical device regulatory systems are similar in many ways, but differ in important ways too, which impacts the afforded level of safety and effectiveness assurance. In both systems, medical devices are classified and regulated on a risk basis, which fundamentally differs from drug regulation, where uniform requirements are imposed. Anesthesia providers must gain knowledge of these systems and be active players in both premarket and postmarket activities, particularly with regard to vigilance and adverse event/device failure reporting.

  11. Surgical tools and medical devices

    CERN Document Server

    Jackson, Mark

    2016-01-01

    This new edition presents information and knowledge on the field of biomedical devices and surgical tools. The authors look at the interactions between nanotechnology, nanomaterials, design, modeling, and tools for surgical and dental applications, as well as how nanostructured surfaces can be created for the purposes of improving cell adhesion between medical devices and the human body. Each original chapter is revised in this second edition and describes developments in coatings for heart valves, stents, hip and knee joints, cardiovascular devices, orthodontic applications, and regenerative materials such as bone substitutes. There are also 8 new chapters that address: Microvascular anastomoses Inhaler devices used for pulmonary delivery of medical aerosols Surface modification of interference screws Biomechanics of the mandible (a detailed case study) Safety and medical devices The synthesis of nanostructured material Delivery of anticancer molecules using carbon nanotubes Nano and micro coatings for medic...

  12. Sustainable Disruptions

    DEFF Research Database (Denmark)

    Friis, Silje Alberthe Kamille; Kjær, Lykke Bloch

    2016-01-01

    Since 2012 the Sustainable Disruptions (SD) project at the Laboratory for Sustainability at Design School Kolding (DK) has developed and tested a set of design thinking tools, specifically targeting the barriers to economically, socially, and environmentally sustainable business development....... The tools have been applied in practice in collaboration with 11 small and medium sized companies (SMEs). The study investigates these approaches to further understand how design thinking can contribute to sustainable transition in a business context. The study and the findings are relevant to organizations...... invested in the issue of sustainable business development, in particular the leaders and employees of SMEs, but also to design education seeking new ways to consciously handle and teach the complexity inherent in sustainable transformation. Findings indicate that the SD design thinking approach contributes...

  13. Computational sustainability

    CERN Document Server

    Kersting, Kristian; Morik, Katharina

    2016-01-01

    The book at hand gives an overview of the state of the art research in Computational Sustainability as well as case studies of different application scenarios. This covers topics such as renewable energy supply, energy storage and e-mobility, efficiency in data centers and networks, sustainable food and water supply, sustainable health, industrial production and quality, etc. The book describes computational methods and possible application scenarios.

  14. Sustainable transformation

    DEFF Research Database (Denmark)

    Andersen, Nicolai Bo

    This paper is about sustainable transformation with a particular focus on listed buildings. It is based on the notion that sustainability is not just a question of energy conditions, but also about the building being robust. Robust architecture means that the building can be maintained and rebuilt...... theoretical lenses. It is proposed that three parameters concerning the ꞌtransformabilityꞌ of the building can contribute to a more nuanced understanding of sustainable transformation: technical aspects, programmatic requirements and narrative value. It is proposed that the concept of ꞌsustainable...

  15. Future options for aerosol delivery to children

    DEFF Research Database (Denmark)

    Bisgaard, H

    1999-01-01

    , allowing less compliant children enough time to obtain a full dose. Eliminating the electrostatic charge can change the lung dose by several times; hence, nonelectrostatic materials should be used in future spacer devices. Compliance is the biggest problem in drug delivery to children. The inhaler design......There is an increasing awareness of the importance of reliable aerosol delivery, with emphasis on the dose delivered to the lungs, optimal clinical control, cost-effectiveness, and safety in children. Dose prescription should relate to the expected lung dose rather than the factory-dispensed dose......, as at present. The device determines the lung dose. Clearly, therefore, the device should be considered an integral part of the prescription. Drug approval processes should clearly specify the device, and discourage the use of other devices. This would rationalize the choice of devices. Important new insights...

  16. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...

  17. Sustaining dairy

    NARCIS (Netherlands)

    Villarreal Herrera, Georgina

    2017-01-01

    Dairy in Europe has undergone many changes in the last few years—the abolition of milk production quotas being a fundamental one. This study explores these changes in relation to the sustained social and environmental viability of the sector and how dairy processors' sustainability

  18. Sustainable Universities

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2011-01-01

    . Declarations tend to have impact on three trends. Firstly, there is emerging international consensus on the university’s role and function in relation to sustainable development; secondly, the emergence of national legislation, and thirdly, an emerging international competition to be leader in sustainable...... campus performance....

  19. Sustainable Transition

    DEFF Research Database (Denmark)

    Hansen, Ole Erik; Søndergård, Bent

    2014-01-01

    of agendas/vision, technologies, actors and institutions in the emergent design of an urban mobility system based on an electric car sharing system. Why. Designing for sustainability is a fundamental challenge for future design practices; designers have to obtain an ability to contribute to sustainable...

  20. Sustainable Learning

    Science.gov (United States)

    Cadwell, Louise; Dillon, Robert

    2011-01-01

    Green schools have moved into a new era that focuses on building a culture of sustainability in every aspect of learning in schools. In the early stages of sustainability education, the focus was on recycling and turning off the lights. Now, students and adults together are moving into the areas of advocacy and action that are based on a deep…

  1. Insertion devices

    CERN Document Server

    Bahrdt, J

    2006-01-01

    The interaction of an insertion device with the electron beam in a storage ring is discussed. The radiation property including brightness, ux and polarization of an ideal and real planar and helical / elliptical device is described. The magnet design of planar, helical, quasiperiodic devices and of devices with a reduced on axis power density are resumed.

  2. SCALING UP A MOBILE TELEMEDICINE SOLUTION IN BOTSWANA: KEYS TO SUSTAINABILITY

    Directory of Open Access Journals (Sweden)

    Kagiso eNdlovu

    2014-12-01

    Full Text Available Effective health care delivery is significantly compromised in an environment where resources, both human and technical, are limited. Botswana’s health care system is one of the many in the African continent with few specialised medical doctors, thereby posing a barrier to patients’ access to health care services. In addition, the traditional landline and non-robust Information Technology (IT network infrastructure characterised by slow bandwidth still dominates the health care system in Botswana. Upgrading of the landline IT infrastructure to meet today’s health care demands is a tedious, long and expensive process. Despite these challenges, there still lies hope in health care delivery utilising wireless telecommunication services. Botswana has recently experienced a tremendous growth in the mobile telecommunication industry coupled with an increase in the number of individually owned mobile devices. This growth inspired the Botswana-UPenn Partnership (BUP to collaborate with local partners to explore using mobile devices as tools to improve access to specialised health care delivery. Pilot studies were conducted across four medical specialties, including radiology, oral medicine, dermatology and cervical cancer screening. Findings from the studies became vital evidence in support of the first scale-up project of a mobile telemedicine solution in Botswana, also known as Kgonafalo. Some technical and social challenges were encountered during the initial studies, such as malfunctioning of mobile devices, accidental damage of devices and cultural misalignment between IT and healthcare providers. These challenges brought about lessons learnt, including a strong need for unwavering senior management support, establishment of solid local public-private partnerships, and efficient project sustainability plans. Sustainability milestones included the development and signing of a Memorandum of Understanding (MOU between the Botswana government and

  3. N-Acetylcarnosine sustained drug delivery eye drops to control the signs of ageless vision: Glare sensitivity, cataract amelioration and quality of vision currently available treatment for the challenging 50,000-patient population

    Directory of Open Access Journals (Sweden)

    Mark A Babizhayev

    2008-10-01

    Full Text Available Mark A Babizhayev1, Leslie Burke2, Philip Micans3, Stuart P Richer4,51Innovative Vision Products, Inc., County of New Castle, Delaware, USA; 2Wise Choice Products LLC, London, England, United Kingdom; 3IAS Group, Sark, United Kingdom; 4Eye Clinic DVA Medical Center, North Chicago, Illinois, USA; 5Department of Family and Preventive Medicine, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, USABackground: Innovative Vision Products, Inc. (IVP’s scientists developed the lubricant eye drops (Can-C™ designed as 1% N-acetylcarnosine (NAC prodrug of L-carnosine containing a mucoadhesive cellulose-based compound combined with corneal absorption promoters in a sustained drug delivery system. Only the natural L-isomeric form of NAC raw material was specifically synthesized at the cGMP facility and employed for the manufacturing of Can-C™ eye drops.Objective and study design: In the present clinical study the authors assessed vision before and after 9 month term of topical ocular administration of NAC lubricant eye drops or placebo in 75 symptomatic patients with age-related uncomplicated cataracts in one or both eyes, with acuity in one eye of 20/40 or worse (best-corrected distance, and no previous cataract surgery in either eye and no other ocular abnormality and 72 noncataract subjects ranged in age from 54 to 78 years.Setting: Subjects in these subsample groups have reported complaints of glare and wanted to administer eye drops to get quick eye relief and quality of vision for their daily activities including driving and computer works. Following 9 months of treatment with NAC lubricant eye drops, most patients’ glare scores were improved or returned to normal in disability glare tests with Halometer DG. Improvement in disability glare was accompanied with independent improvement in acuity. Furthermore, patients with the poorest pretreatment vision were as likely to regain certain better visual function after 9

  4. N-Acetylcarnosine sustained drug delivery eye drops to control the signs of ageless vision: glare sensitivity, cataract amelioration and quality of vision currently available treatment for the challenging 50,000-patient population.

    Science.gov (United States)

    Babizhayev, Mark A; Burke, Leslie; Micans, Philip; Richer, Stuart P

    2009-01-01

    Innovative Vision Products, Inc. (IVP)'s scientists developed the lubricant eye drops (Can-C) designed as 1% N-acetylcarnosine (NAC) prodrug of L-carnosine containing a mucoadhesive cellulose-based compound combined with corneal absorption promoters in a sustained drug delivery system. Only the natural L-isomeric form of NAC raw material was specifically synthesized at the cGMP facility and employed for the manufacturing of Can-C eye drops. In the present clinical study the authors assessed vision before and after 9 month term of topical ocular administration of NAC lubricant eye drops or placebo in 75 symptomatic patients with age-related uncomplicated cataracts in one or both eyes, with acuity in one eye of 20/40 or worse (best-corrected distance), and no previous cataract surgery in either eye and no other ocular abnormality and 72 noncataract subjects ranged in age from 54 to 78 years. Subjects in these subsample groups have reported complaints of glare and wanted to administer eye drops to get quick eye relief and quality of vision for their daily activities including driving and computer works. Following 9 months of treatment with NAC lubricant eye drops, most patients' glare scores were improved or returned to normal in disability glare tests with Halometer DG. Improvement in disability glare was accompanied with independent improvement in acuity. Furthermore, patients with the poorest pretreatment vision were as likely to regain certain better visual function after 9 months of treatment with N-acetylcarnosine lubricant eye drops as those with the worth pretreatment vision. The authors made a reference to electronic records of the product sales to patients who have been made the repurchase of the Can-C eye drops since December 2001. Based on this analysis of recorded adjustments to inventory, various parameters were analyzed during the continued repurchase behavior program, including testimonials from buyers. With these figures, researchers judged on the

  5. Transdermal delivery of insulin via microneedles.

    Science.gov (United States)

    Narayan, Roger J

    2014-09-01

    Treatment of insulin-dependent diabetes mellitus, also known as Type 1 diabetes mellitus, requires delivery of exogenous insulin via injection or pump. An alternative to syringe-based subcutaneous delivery of insulin involves use of microneedles. These delivery of insulin. Benefits associated with microneedle-based delivery of insulin include minimal training for use, painless insertion, as well as the potential to combine microneedles with sensors and drug delivery devices to create an autonomous artificial pancreas. In this review, the efforts of academic and industrial researchers over the past decade to examine the functionality of microneedles for delivery of insulin, including insulin-containing nanomaterials, via in vitro, ex vivo, and in vivo studies are considered.

  6. Chitosan Films: A Potential Local Drug Delivery System for Antibiotics

    OpenAIRE

    Noel, Scott P.; Courtney, Harry; Bumgardner, Joel D.; Warren O. Haggard

    2008-01-01

    Local antibiotic delivery is an emerging area of study designed to provide alternative methods of treatment to clinicians for compromised wound sites where avascular zones can prevent the delivery of antibiotics to the infected tissue. Antibiotic-loaded bone cement is the gold standard for drug-eluting local delivery devices but is not ideal because it requires a removal surgery. Chitosan is a biocompatible, biodegradable polymer that has been used in several different drug delivery applicati...

  7. Sustainable Chemistry at Sungkyunkwan University.

    Science.gov (United States)

    Park, Nam-Gyu

    2015-07-20

    Special Issue: Sustainable Chemistry at Sungkyunkwan University. Sustainable chemistry is key to the development of efficient renewable energies, which will become more and more important in order to combat global warming. In this Editorial, guest editor Prof. Nam-Gyu Park describes the context of this Special Issue on top-quality research towards sustainability performed at Sungkyunkwan University (SKKU) in Korea. Scientists at SKKU work on, for example, photovoltaic solar cells to generate low-cost electricity, lithium batteries and capacitors to store electricity, piezoelectric nanogenerators, thermoelectric devices, hydrogen generation, and fuel cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Sustainable consumption

    DEFF Research Database (Denmark)

    Prothero, Andrea; Dobscha, Susan; Freund, Jim

    2011-01-01

    This essay explores sustainable consumption and considers possible roles for marketing and consumer researchers and public policy makers in addressing the many sustainability challenges that pervade our planet. Future research approaches to this interdisciplinary topic need to be comprehensive...... and systematic and will benefit from a variety of different perspectives. There are a number of opportunities for future research, and three areas are explored in detail. First, the essay considers the inconsistency between the attitudes and behaviors of consumers with respect to sustainability; next, the agenda...... is broadened to explore the role of individual citizens in society; and finally, a macro institutional approach to fostering sustainability is explored. Each of these areas is examined in detail and possible research avenues and public policy initiatives are considered within each of these separate...

  9. Stabilizing Sustainability

    DEFF Research Database (Denmark)

    Reitan Andersen, Kirsti

    The publication of the Brundtland Report in 1987 put the topic of sustainable development on the political and corporate agenda. Defining sustainable development as “a development that meets the needs of the future without compromising the ability of future generations to meet their own needs......” (WCED, 1987, p. 43), the Report also put a positive spin on the issue of sustainability by upholding capitalist beliefs in the possibility of infinite growth in a world of finite resources. While growth has delivered benefits, however, it has done so unequally and unsustainably. This thesis focuses...... on the textile and fashion industry, one of the world’s most polluting industries and an industry to some degree notorious for leading the ‘race to the bottom’ in global labour standards. Despite being faced with increasing demands to practise sustainability, most textile and fashion companies continue to fail...

  10. Sustainability reporting

    NARCIS (Netherlands)

    Kolk, A.

    2005-01-01

    This article gives an overview of developments in sustainability (also sometimes labelled corporate social responsibility) reporting. The article will first briefly indicate how accountability on social and environmental issues started, already in the 1970s when social reports were published.

  11. Sustainable Cities

    DEFF Research Database (Denmark)

    Georg, Susse; Garza de Linde, Gabriela Lucía

    Judging from the number of communities and cities striving or claiming to be sustainable and how often eco-development is invoked as the means for urban regeneration, it appears that sustainable and eco-development have become “the leading paradigm within urban development” (Whitehead 2003......), urban design competitions are understudied mechanisms for bringing about field level changes. Drawing on actor network theory, this paper examines how urban design competitions may bring about changes within the professional field through the use of intermediaries such as a sustainable planning....../assessment tool. The context for our study is urban regeneration in one Danish city, which had been suffering from industrial decline and which is currently investing in establishing a “sustainable city”. Based on this case study we explore how the insights and inspiration evoked in working with the tool...

  12. Sustainable responsibilities?

    DEFF Research Database (Denmark)

    Lystbæk, Christian Tang

    2015-01-01

    This working paper analyzes the conceptions of corporate responsibility for sustainable development in EU policies on CSR. The notion of corporate responsibility has until recently been limited to economical and legal responsibilities. Based on this narrow conception of corporate responsibility.......e. a combination of destruction and construction, this chapter will deconstruct conceptions of responsibility for sustainable development in these EU documents on CSR. A deconstructive conceptual analysis involves destructing dominant interpretations of a text and allowing for constructions of alternative...... such as sustainability actually means, but on what the concept says and does not say. A deconstructive analysis of EU policies on CSR, then, pinpoints that such policies are sites of conceptual struggles. This kind of analysis is suitable for studying conceptions of corporate responsibility for sustainable development...

  13. Agriculture: Sustainability

    Science.gov (United States)

    Sustainability creates and maintains the conditions under which humans and nature can exist in productive harmony, that permit fulfilling the food, feed, and fiber needs of our country and the social, economic and other requirements.

  14. Biomedical devices and their applications

    CERN Document Server

    2004-01-01

    This volume introduces readers to the basic concepts and recent advances in the field of biomedical devices. The text gives a detailed account of novel developments in drug delivery, protein electrophoresis, estrogen mimicking methods and medical devices. It also provides the necessary theoretical background as well as describing a wide range of practical applications. The level and style make this book accessible not only to scientific and medical researchers but also to graduate students.

  15. Removal of Escherichia coli and Faecal Coliforms from Surface Water and Groundwater by Household Water Treatment Devices/Systems: A Sustainable Solution for Improving Water Quality in Rural Communities of the Southern African Development Community Region

    Directory of Open Access Journals (Sweden)

    Jocelyne K. Mwabi

    2012-01-01

    Full Text Available There is significant evidence that household water treatment devices/systems (HWTS are capable of dramatically improving microbially contaminated water quality. The purpose of this study was to examine five filters [(biosand filter-standard (BSF-S; biosand filter-zeolite (BSF-Z; bucket filter (BF; ceramic candle filter (CCF; and silver-impregnated porous pot (SIPP] and evaluate their ability to improve the quality of drinking water at the household level. These HWTS were manufactured in the workshop of the Tshwane University of Technology and evaluated for efficiency to remove turbidity, faecal coliforms and Escherichia coli from multiple water source samples, using standard methods. The flow rates ranged from 0.05 L/h to 2.49 L/h for SIPP, 1 L/h to 4 L/h for CCF, 0.81 L/h to 6.84 L/h for BSF-S, 1.74 L/h to 19.2 L/h and 106.5 L/h to 160.5 L/h for BF The turbidity of the raw water samples ranged between 2.17 and 40.4 NTU. The average turbidity obtained after filtration ranged from 0.6 to 8 NTU (BSF-S, 1 to 4 NTU (BSF-Z, 2 to 11 NTU (BF, and from 0.6 to 7 NTU (CCF and 0.7 to 1 NTU for SIPP. The BSF-S, BSF-Z and CCF removed 2 to 4 log10 (99% to 100% of coliform bacteria, while the BF removed 1 to 3 log (90% to 99.9% of these bacteria. The performance of the SIPP in removing turbidity and indicator bacteria (>5 log10, 100% was significantly higher compared to that of the other HWTS (p < 0.05. The findings of this study indicate that the SIPP can be an effective and sustainable HWTS for the Southern African Development Community (SADC rural communities, as it removed the total concentration of bacteria from test water, can be manufactured using locally available materials, and is easy to operate and to maintain.

  16. Removal of Escherichia coli and faecal coliforms from surface water and groundwater by household water treatment devices/systems: a sustainable solution for improving water quality in rural communities of the Southern African development community region.

    Science.gov (United States)

    Mwabi, Jocelyne K; Mamba, Bhekie B; Momba, Maggy N B

    2012-01-01

    There is significant evidence that household water treatment devices/systems (HWTS) are capable of dramatically improving microbially contaminated water quality. The purpose of this study was to examine five filters [(biosand filter-standard (BSF-S); biosand filter-zeolite (BSF-Z); bucket filter (BF); ceramic candle filter (CCF); and silver-impregnated porous pot (SIPP)] and evaluate their ability to improve the quality of drinking water at the household level. These HWTS were manufactured in the workshop of the Tshwane University of Technology and evaluated for efficiency to remove turbidity, faecal coliforms and Escherichia coli from multiple water source samples, using standard methods. The flow rates ranged from 0.05 L/h to 2.49 L/h for SIPP, 1 L/h to 4 L/h for CCF, 0.81 L/h to 6.84 L/h for BSF-S, 1.74 L/h to 19.2 L/h and 106.5 L/h to 160.5 L/h for BF The turbidity of the raw water samples ranged between 2.17 and 40.4 NTU. The average turbidity obtained after filtration ranged from 0.6 to 8 NTU (BSF-S), 1 to 4 NTU (BSF-Z), 2 to 11 NTU (BF), and from 0.6 to 7 NTU (CCF) and 0.7 to 1 NTU for SIPP. The BSF-S, BSF-Z and CCF removed 2 to 4 log(10) (99% to 100%) of coliform bacteria, while the BF removed 1 to 3 log (90% to 99.9%) of these bacteria. The performance of the SIPP in removing turbidity and indicator bacteria (>5 log(10), 100%) was significantly higher compared to that of the other HWTS (p < 0.05). The findings of this study indicate that the SIPP can be an effective and sustainable HWTS for the Southern African Development Community (SADC) rural communities, as it removed the total concentration of bacteria from test water, can be manufactured using locally available materials, and is easy to operate and to maintain.

  17. Sustainable finance

    OpenAIRE

    Boersma-de Jong, Margreet F.

    2012-01-01

    Presentation for Springschool of Strategy, University of Groningen, 10 October 2012. The role of CSR is to stimulate ethical behaviour, and as a result, mutual trust in society. Advantage of CSR for the company and the evolution of CSR. From CSR to Sustainable Finance: how does CSR influence Sustainable Business Administration & Management Accounting, Financial Leadership and what is the importance of CSR in the financial sector

  18. Sustainability on-the-go

    DEFF Research Database (Denmark)

    Kampf, Constance Elizabeth

    How are the available means for interaction about sustainability affected by mobile communication technologies? What are the implications of this change for communicating sustainable values? This presentation compares strategies between three organizations whose values and objectives focus...... on sustainability-- The Good Guide, Carrotmob and Colalife. Each organization demonstrates a web presence through social media that are available on mobile devices. This paper examines the mobile space as a space for examining the potential impacts of a technology mediated interaction focused on sustainability....... To explore this mobile space as a space not only for communication, but for identification (Burke 1950), Gee’s concepts of (D) and (d) discourse are used and synthesized with Burke’s notions of terministic screens and entitlement (Burke 1966), leading to an understanding of sustainability values...

  19. SUSTAINABLE TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    Linda STEG

    2007-01-01

    Full Text Available This paper discusses possible contributions of psychologists to sustainable transportation. It is argued that in order to reach sustainable transportation, among others, behaviour changes of individual car users are needed. As transport policies will be more effective if they target important antecedents of travel behaviour, first, factors influencing such behaviour are discussed. It is argued that car use is very attractive and sometimes even necessary for many different reasons. This implies that a combination of policies is called for, each targeting different factors that support car use and hinder the use of more sustainable modes of transport. Next, the paper elaborates on policy strategies that may be employed to achieve sustainable transportation by changing car use. Increasing the attractiveness of sustainable transport modes by means of pull measures seems not sufficient to reduce the level of car use. Besides, car use should be made less attractive by means of push measures to force drivers to reconsider their travel behaviour. The acceptability of such policies may be increased by clearly communicating the aim of these policies, and the expected positive consequences (e.g., less congestion, improved environmental quality. Moreover, possible negative effects for individual freedom may be compensated by implementing additional policies aimed at facilitating the use of sustainable transport modes.

  20. Sustainable markets for sustainable energy

    Energy Technology Data Exchange (ETDEWEB)

    Millan, J.; Smyser, C.

    1997-12-01

    The author discusses how the Inter-American Development Bank (IDB) is involved in sustainable energy development. It presently has 50 loans and grants for non conventional renewable energy projects and ten grants for efficiency programs for $600 and $17 million respectively, representing 100 MW of power. The IDB is concerned with how to create a sustainable market for sustainable energy projects. The IDB is trying to work with government, private sector, NGOs, trading allies, credit sources, and regulators to find proper roles for such projects. He discusses how the IDB is working to expand its vision and objectives in renewable energy projects in Central and South America.

  1. Towards effective extension delivery approach and strategies for ...

    African Journals Online (AJOL)

    Towards effective extension delivery approach and strategies for food security poverty alleviation and sustainable development in Nigeria. ... System (REFILS) will ensure clarity, judicious resource utilization, empowerment of beneficiaries and control of quality of technologies and contents of information disseminated.

  2. Intradermal Insulin Delivery

    Science.gov (United States)

    Hultström, Michael; Roxhed, Niclas

    2014-01-01

    The incidence of insulinopenic diabetes mellitus is constantly increasing, and in addition, approximately a third of all hyperinsulinemic diabetic patients develop insulinopenia. Optimal glycemic control is essential to minimize the risk for diabetes-induced complications, but the majority of diabetic patients fail to achieve proper long-term glucose levels even in clinical trials, and even more so in clinical practice. Compliance with a treatment regimen is likely to be higher if the procedure is simple, painless, and discreet. Thus, insulin has been suggested for nasal, gastrointestinal, and inhalation therapy, but so far with considerable downsides in effect, side effects, or patient acceptance. The stratum corneum is the main barrier preventing convenient drug administration without the drawbacks of subcutaneous injections. Recently, devices with miniaturized needles have been developed that combine the simplicity and discretion of patch-based treatments, but with the potential of peptide and protein administration. As this review describes, initial comparisons with subcutaneous administration now suggest microneedle patches for active insulin delivery are efficient in maintaining glycemic control. Hollow microneedle technology could also prove to be efficient in systemic as well as local delivery of other macromolecular drugs, such as vaccines. PMID:24876605

  3. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  4. Photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  5. Concentration device

    DEFF Research Database (Denmark)

    2013-01-01

    A concentration device (2) for filter filtration concentration of particles (4) from a volume of a fluid (6). The concentration device (2) comprises a filter (8) configured to filter particles (4) of a predefined size in the volume of the fluid (6). The concentration device (2) comprises...

  6. Toward Environmentally Sustainable Mobile Computing Through an Economic Framework

    National Research Council Canada - National Science Library

    Joseph, Siny; Namboodiri, Vinod; Dev, Vishnu Cherusola

    2014-01-01

    .... Prior work with energy efficiency in mobile devices has primarily focused on the goal of maximizing battery life of these devices and not on the broader concept of environmentally sustainable mobile computing...

  7. 21 CFR 801.127 - Medical devices; expiration of exemptions.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical devices; expiration of exemptions. 801.127... (CONTINUED) MEDICAL DEVICES LABELING Exemptions From Adequate Directions for Use § 801.127 Medical devices; expiration of exemptions. (a) If a shipment or delivery, or any part thereof, of a device which is exempt...

  8. 21 CFR 801.110 - Retail exemption for prescription devices.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Retail exemption for prescription devices. 801.110... (CONTINUED) MEDICAL DEVICES LABELING Exemptions From Adequate Directions for Use § 801.110 Retail exemption for prescription devices. A device subject to § 801.109 shall be exempt at the time of delivery to the...

  9. Protein-Based Drug-Delivery Materials

    Science.gov (United States)

    Jao, Dave; Xue, Ye; Medina, Jethro; Hu, Xiao

    2017-01-01

    There is a pressing need for long-term, controlled drug release for sustained treatment of chronic or persistent medical conditions and diseases. Guided drug delivery is difficult because therapeutic compounds need to survive numerous transport barriers and binding targets throughout the body. Nanoscale protein-based polymers are increasingly used for drug and vaccine delivery to cross these biological barriers and through blood circulation to their molecular site of action. Protein-based polymers compared to synthetic polymers have the advantages of good biocompatibility, biodegradability, environmental sustainability, cost effectiveness and availability. This review addresses the sources of protein-based polymers, compares the similarity and differences, and highlights characteristic properties and functionality of these protein materials for sustained and controlled drug release. Targeted drug delivery using highly functional multicomponent protein composites to guide active drugs to the site of interest will also be discussed. A systematical elucidation of drug-delivery efficiency in the case of molecular weight, particle size, shape, morphology, and porosity of materials will then be demonstrated to achieve increased drug absorption. Finally, several important biomedical applications of protein-based materials with drug-delivery function—including bone healing, antibiotic release, wound healing, and corneal regeneration, as well as diabetes, neuroinflammation and cancer treatments—are summarized at the end of this review. PMID:28772877

  10. Protein-Based Drug-Delivery Materials

    Directory of Open Access Journals (Sweden)

    Dave Jao

    2017-05-01

    Full Text Available There is a pressing need for long-term, controlled drug release for sustained treatment of chronic or persistent medical conditions and diseases. Guided drug delivery is difficult because therapeutic compounds need to survive numerous transport barriers and binding targets throughout the body. Nanoscale protein-based polymers are increasingly used for drug and vaccine delivery to cross these biological barriers and through blood circulation to their molecular site of action. Protein-based polymers compared to synthetic polymers have the advantages of good biocompatibility, biodegradability, environmental sustainability, cost effectiveness and availability. This review addresses the sources of protein-based polymers, compares the similarity and differences, and highlights characteristic properties and functionality of these protein materials for sustained and controlled drug release. Targeted drug delivery using highly functional multicomponent protein composites to guide active drugs to the site of interest will also be discussed. A systematical elucidation of drug-delivery efficiency in the case of molecular weight, particle size, shape, morphology, and porosity of materials will then be demonstrated to achieve increased drug absorption. Finally, several important biomedical applications of protein-based materials with drug-delivery function—including bone healing, antibiotic release, wound healing, and corneal regeneration, as well as diabetes, neuroinflammation and cancer treatments—are summarized at the end of this review.

  11. Electronic Nicotine Delivery Systems.

    Science.gov (United States)

    Walley, Susan C; Jenssen, Brian P

    2015-11-01

    Electronic nicotine delivery systems (ENDS) are rapidly growing in popularity among youth. ENDS are handheld devices that produce an aerosolized mixture from a solution typically containing concentrated nicotine, flavoring chemicals, and propylene glycol to be inhaled by the user. ENDS are marketed under a variety of names, most commonly electronic cigarettes and e-cigarettes. In 2014, more youth reported using ENDS than any other tobacco product. ENDS pose health risks to both users and nonusers. Nicotine, the major psychoactive ingredient in ENDS solutions, is both highly addictive and toxic. In addition to nicotine, other toxicants, carcinogens, and metal particles have been detected in solutions and aerosols of ENDS. Nonusers are involuntarily exposed to the emissions of these devices with secondhand and thirdhand aerosol. The concentrated and often flavored nicotine in ENDS solutions poses a poisoning risk for young children. Reports of acute nicotine toxicity from US poison control centers have been increasing, with at least 1 child death reported from unintentional exposure to a nicotine-containing ENDS solution. With flavors, design, and marketing that appeal to youth, ENDS threaten to renormalize and glamorize nicotine and tobacco product use. There is a critical need for ENDS regulation, legislative action, and counter promotion to protect youth. ENDS have the potential to addict a new generation of youth to nicotine and reverse more than 50 years of progress in tobacco control. Copyright © 2015 by the American Academy of Pediatrics.

  12. Recent Patents in Pulmonary Delivery of Macromolecules.

    Science.gov (United States)

    Ray, Animikh; Mandal, Abhirup; Mitra, Ashim K

    2015-01-01

    Pulmonary delivery is a non-invasive form of delivery that holds tremendous therapeutic promise for topical and systemic administration of several macromolecules. Oral administration of macromolecules has several limitations such as low bioavailability, degradation of drug before reaching circulation and insufficient absorption across intestinal membrane. Administration of macromolecules such as proteins, peptides and nucleic acids via inhalation offers great potential due to the avoidance of first pass metabolism, higher surface area and rapid clinical response. However, delivery of reproducible, uniform and safe doses of inhaled particles remains a major challenge for clinical translation. Recent advances in the fields of biotechnology and particle engineering led to progress in novel pulmonary drug delivery systems. Moreover, significant developments in carriers and delivery devices prevent denaturation of macromolecules and control their release within the lungs. This article reviews the advances in pulmonary drug delivery systems by focusing on the recent patents in delivery of macromolecules. Furthermore, recent patents in gene delivery to the lungs have also been discussed. List of patents included in this review is comprehensive in terms of pulmonary delivery of therapeutics. It includes inventions related to proteins and peptides, DNA therapeutics, siRNA and other genetic materials with therapeutic applications. The diseases targeted by these therapeutic molecules are varied including but not limited to different forms of cancer, respiratory diseases etc.

  13. Roundtabling Sustainability

    DEFF Research Database (Denmark)

    Ponte, Stefano

    2014-01-01

    The willingness of public authority to delegate social and environmental regulation to the private sector has varied from sector to sector, but has often led to the establishment of ‘voluntary’ standards and certifications on sustainability. Many of these have taken the form of ‘stewardship...... councils’ and ‘sustainability roundtables’ and have been designed around a set of institutional features seeking to establish legitimacy, fend off possible criticism, and ‘sell’ certifications to potential users. The concept of ‘roundtabling’ emphasizes the fitting a variety of commodity......-specific sustainability situations into a form that not only ‘hears more voices’ (as in ‘multi-stakeholder’), but also portrays to give them equal standing at the table of negotiations (roundtable), thus raising higher expectations on accountability, transparency and inclusiveness. In this article, I examine to what...

  14. Sustainability Evaluation.

    Science.gov (United States)

    Stichnothe, Heinz

    2017-03-17

    The long-term substitution of fossil resources can only be achieved through a bio-based economy, with biorefineries and bio-based products playing a major role. However, it is important to assess the implications of the transition to a bio-based economy. Life cycle-based sustainability assessment is probably the most suitable approach to quantify impacts and to identify trade-offs at multiple levels. The extended utilisation of biomass can cause land use change and affect food security of the most vulnerable people throughout the world. Although this is mainly a political issue and governments should be responsible, the responsibility is shifted to companies producing biofuels and other bio-based products. Organic wastes and lignocellulosic biomass are considered to be the preferred feedstock for the production of bio-based products. However, it is unlikely that a bio-based economy can rely only on organic wastes and lignocellulosic biomass.It is crucial to identify potential problems related to socio-economic and environmental issues. Currently there are many approaches to the sustainability of bio-based products, both quantitative and qualitative. However, results of different calculation methods are not necessarily comparable and can cause confusion among decision-makers, stakeholders and the public.Hence, a harmonised, globally agreed approach would be the best solution to secure sustainable biomass/biofuels/bio-based chemicals production and trade, and to avoid indirect effects (e.g. indirect land use change). However, there is still a long way to go.Generally, the selection of suitable indicators that serve the purpose of sustainability assessment is very context-specific. Therefore, it is recommended to use a flexible and modular approach that can be adapted to various purposes. A conceptual model for the selection of sustainability indicators is provided that facilitates identifying suitable sustainability indicators based on relevance and significance in a

  15. Gastroretentive delivery systems: a mini review.

    Science.gov (United States)

    Talukder, R; Fassihi, R

    2004-01-01

    Various attempts have been made to develop gastroretentive delivery systems. For example, floating, swelling, mucoadhesive, and high-density systems have been developed to increase gastric retention time of the dosage forms. It is known that differences in gastric physiology, such as, gastric pH, and motility exhibit both intra- as well as inter-subject variability demonstrating significant impact on gastric retention time and drug delivery behavior. Nevertheless, some floating devices have shown promising results. In this paper, the gastric physiology and the reported intragastric delivery systems have briefly been presented.

  16. Iontophoretically Enhanced Ciclopirox Delivery into and Across Human Nail Plate

    OpenAIRE

    HAO, JINSONG; SMITH, KELLY A.; LI, S. KEVIN

    2009-01-01

    Transungual delivery of antifungal drugs is hindered by the low permeability of human nail plates, and as such, repeated dosing over a long period of time is necessary for effective treatment. The objectives of this study were to explore the possibilities of (a) enhancing the delivery of ciclopirox (CIC) across human nail plates and (b) sustaining CIC delivery from the larger resultant drug depot in the nail plates with constant voltage iontophoresis. In vitro passive and 9 V cathodal iontoph...

  17. Microspheres for the Drug Delivery Applications

    Directory of Open Access Journals (Sweden)

    Hafiz Shoaib Sarwar

    2014-12-01

    Full Text Available Conventional dosage forms provide a sharp increase in plasma drug levels that falls below the therapeutic range after short interval of time until the re-administration of drug. There is a need of such dosage forms which provide not only sustained drug delivery but also reduce the plasma drug levels fluctuations. Microspheres used in drug delivery systems due to their ability to sustain the drug release, their biodegradability and compatibility and targeted drug delivery. In this review different types of microspheres their methods for the preparation with different hydrophilic and hydrophobic polymers, drug loading capacities will be discussed. Different characterizations like SEM, FTIR, XRD, DSC, rheological properties and invitro drug release are successfully described.

  18. Sustainable web ecosystem design

    CERN Document Server

    O'Toole, Greg

    2013-01-01

    This book is about the process of creating web-based systems (i.e., websites, content, etc.) that consider each of the parts, the modules, the organisms - binary or otherwise - that make up a balanced, sustainable web ecosystem. In the current media-rich environment, a website is more than a collection of relative html documents of text and images on a static desktop computer monitor. There is now an unlimited combination of screens, devices, platforms, browsers, locations, versions, users, and exabytes of data with which to interact. Written in a highly approachable, practical style, this boo

  19. Sustainable Soesterkwartier

    NARCIS (Netherlands)

    Abrahams, H.; Goosen, H.; Jong, de F.; Sickmann, J.; Prins, D.

    2010-01-01

    The municipality of Amersfoort wants to construct an endurable and sustainable eco-town in the Soesterkwartier neighbourhood, by taking future climate change into account. The impact of climate change at the location of the proposed eco-town was studied by a literature review.

  20. Sustainable agriculture

    International Development Research Centre (IDRC) Digital Library (Canada)

    New farming techniques, better food security. Since 1970, IDRC-supported research has introduced sustainable agricultural practices to farmers and communities across the devel- oping world. The result: higher productivity, less poverty, greater food security, and a healthier environment. Opportunities grow on trees in ...

  1. Sustainable Development

    African Journals Online (AJOL)

    Tsegai Berhane Ghebretekle

    Abstract. This article examines the concept of sustainable development after the Post-. 2015 Paris Climate Change Agreement with particular emphasis on Ethiopia. Various African countries are vulnerable to climate change, as is evidenced by recent droughts. Ethiopia is selected as a case study in light of its pace in.

  2. Sustainable machining

    CERN Document Server

    2017-01-01

    This book provides an overview on current sustainable machining. Its chapters cover the concept in economic, social and environmental dimensions. It provides the reader with proper ways to handle several pollutants produced during the machining process. The book is useful on both undergraduate and postgraduate levels and it is of interest to all those working with manufacturing and machining technology.

  3. Architecture Sustainability

    NARCIS (Netherlands)

    Avgeriou, Paris; Stal, Michael; Hilliard, Rich

    2013-01-01

    Software architecture is the foundation of software system development, encompassing a system's architects' and stakeholders' strategic decisions. A special issue of IEEE Software is intended to raise awareness of architecture sustainability issues and increase interest and work in the area. The

  4. Sustainability reporting

    NARCIS (Netherlands)

    Kolk, A.

    2005-01-01

    This article gives an overview of developments in sustainability (also sometimes labelled corporate social responsibility) reporting. It The article will first briefly indicate how accountability on social and environmental issues started, already in the 1970s when social reports were published.

  5. Exergy sustainability.

    Energy Technology Data Exchange (ETDEWEB)

    Robinett, Rush D. III (.; ); Wilson, David Gerald; Reed, Alfred W.

    2006-05-01

    Exergy is the elixir of life. Exergy is that portion of energy available to do work. Elixir is defined as a substance held capable of prolonging life indefinitely, which implies sustainability of life. In terms of mathematics and engineering, exergy sustainability is defined as the continuous compensation of irreversible entropy production in an open system with an impedance and capacity-matched persistent exergy source. Irreversible and nonequilibrium thermodynamic concepts are combined with self-organizing systems theories as well as nonlinear control and stability analyses to explain this definition. In particular, this paper provides a missing link in the analysis of self-organizing systems: a tie between irreversible thermodynamics and Hamiltonian systems. As a result of this work, the concept of ''on the edge of chaos'' is formulated as a set of necessary and sufficient conditions for stability and performance of sustainable systems. This interplay between exergy rate and irreversible entropy production rate can be described as Yin and Yang control: the dialectic synthesis of opposing power flows. In addition, exergy is shown to be a fundamental driver and necessary input for sustainable systems, since exergy input in the form of power is a single point of failure for self-organizing, adaptable systems.

  6. Sustainable processing

    DEFF Research Database (Denmark)

    Kristensen, Niels Heine

    2004-01-01

    Kristensen_NH and_Beck A: Sustainable processing. In Otto Schmid, Alexander Beck and Ursula Kretzschmar (Editors) (2004): Underlying Principles in Organic and "Low-Input Food" Processing - Literature Survey. Research Institute of Organic Agriculture FiBL, CH-5070 Frick, Switzerland. ISBN 3-906081-58-3...

  7. Sustainable finance

    NARCIS (Netherlands)

    dr. Margreet F. Boersma-de Jong

    2012-01-01

    Presentation for Springschool of Strategy, University of Groningen, 10 October 2012. The role of CSR is to stimulate ethical behaviour, and as a result, mutual trust in society. Advantage of CSR for the company and the evolution of CSR. From CSR to Sustainable Finance: how does CSR influence

  8. Multi-Device to Multi-Device (MD2MD Content-Centric Networking Based on Multi-RAT Device

    Directory of Open Access Journals (Sweden)

    Cheolhoon Kim

    2017-11-01

    Full Text Available This paper proposes a method whereby a device can transmit and receive information using a beacon, and also describes application scenarios for the proposed method. In a multi-device to multi-device (MD2MD content-centric networking (CCN environment, the main issue involves searching for and connecting to nearby devices. However, if a device can’t find another device that satisfies its requirements, the connection is delayed due to the repetition of processes. It is possible to rapidly connect to a device without repetition through the selection of the optimal device using the proposed method. Consequently, the proposed method and scenarios are advantageous in that they enable efficient content identification and delivery in a content-centric Internet of Things (IoT environment, in which multiple mobile devices coexist.

  9. Application of a GIS-BIOLOCO tool for the design and assessment of biomass delivery chains

    NARCIS (Netherlands)

    Geijzendorffer, I.R.; Annevelink, E.; Elbersen, B.S.; Smidt, R.A.; Mol, de R.M.

    2008-01-01

    The spatial fragmentation of different biomass sources in one or more regions makes design and assessment of sustainable biomass delivery chains rather complicated. This paper presents a GIS tool that supports the design and facilitates a sustainability assessment of biomass delivery chains at a

  10. Cosmetic devices based on active transdermal technologies.

    Science.gov (United States)

    Scott, Jessica A; Banga, Ajay K

    2015-01-01

    Active transdermal technology, commonly associated with drug delivery, has been used in recent years by the cosmetic industry for the aesthetic restoration of skin and delivery of cosmetic agents. In this article, we provide an overview of the skin's structure, various skin types, skin's self-repair mechanisms that are stimulated from the usage of cosmetic devices and discuss cosmetic applications. Summaries of the most common active transdermal technologies such as microneedles, iontophoresis, sonophoresis, lasers and microdermabrasion will be provided, in relation to the marketed cosmetic devices available that incorporate these technologies. Lastly, we cover combinations of active technologies that allow for more enhanced cosmetic results, and the current limitations of cosmetic devices.

  11. SUSTAINABLE CORPORATE AND SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    DORU CÎRNU

    2017-06-01

    Full Text Available In recent decades, the image of the international business environment has changed significantly. Studies conducted by UNCTAD shows that corporate phenomenon developments in the world economy is growing. Without claiming to present an exhaustive topic so vast we tried to capture some "facets" of sustainable development from the perspective of multinational corporations, given the expansion of these economic entities and strengthening their power in the global economy. We present more negative aspects of the actions of multinational corporations in terms of sustainable development, it is very important to know both sides of the coin, which will not only help transnational giants including release. Based on issues such as corporate social responsibility, environmental pollution and workers' rights, we sought to counter official statements. The conclusion is that these economic entities are real forces that can not be ignored in today's world and the obvious problem of sustainable development can not be addressed independently of the phenomenon, context we also identified some possible solutions to conflict of corporations and essence of the concept of sustainable development.

  12. Sustainable Consumption

    DEFF Research Database (Denmark)

    Røpke, Inge

    2015-01-01

    in wider social, economic and technological frameworks is emphasised. In particular, the chapter is inspired by practice theory and transition theory. First, various trends in consumption are outlined to highlight some of the challenges for sustainability transitions. Then, it is discussed how consumption...... patterns are shaped over time and what should be considered in sustainability strategies. While discussions on consumption often take their point of departure in the perspective of the individual and then zoom to the wider context, the present approach is the opposite. The outline starts with the basic...... biophysical, distributional and economic conditions for high consumption in rich countries and then zooms in on the coevolution of provision systems and consumption, and how consumption is shaped by practices and projects in everyday life. Furthermore, the paper discusses whether and how transition...

  13. Sustainable Buildings

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Elle, Morten

    The scientific community agrees that: all countries must drastically and rapidly reduce their CO2 emissions and that energy efficient houses play a decisive role in this. The general attitude at the workshop on Sustainable Buildings was that we face large and serious climate change problems that ...... that need urgent action. The built environment is an obvious area to put effort into because of the large and cost-effective energy saving potential and potential for Renewable Energy-based supply systems for buildings.......The scientific community agrees that: all countries must drastically and rapidly reduce their CO2 emissions and that energy efficient houses play a decisive role in this. The general attitude at the workshop on Sustainable Buildings was that we face large and serious climate change problems...

  14. REVIEW ON GOLD NANO PARTICLE FOR NOVEL DRUG DELIVERY SYSTEM

    OpenAIRE

    Lalit Kumawat; Arpit Jain

    2012-01-01

    Drug delivery technologies are patent protected formulation technologies that modify drug release profile, absorption, distribution and elimination for the benefit of improving product efficacy and safety, as well as patient convenience and compliance .Delivery devices already exist that can release two drugs, but the timing of the release must be built into the device and it cannot be controlled from outside the body. But the new system gold nanoparticles are controlled externally and theore...

  15. Dissolving microneedles for transdermal drug delivery.

    Science.gov (United States)

    Lee, Jeong W; Park, Jung-Hwan; Prausnitz, Mark R

    2008-05-01

    Microfabrication technology has been adapted to produce micron-scale needles as a safer and painless alternative to hypodermic needle injection, especially for protein biotherapeutics and vaccines. This study presents a design that encapsulates molecules within microneedles that dissolve within the skin for bolus or sustained delivery and leave behind no biohazardous sharp medical waste. A fabrication process was developed based on casting a viscous aqueous solution during centrifugation to fill a micro-fabricated mold with biocompatible carboxymethylcellulose or amylopectin formulations. This process encapsulated sulforhodamine B, bovine serum albumin, and lysozyme; lysozyme was shown to retain full enzymatic activity after encapsulation and to remain 96% active after storage for 2 months at room temperature. Microneedles were also shown to be strong enough to insert into cadaver skin and then to dissolve within minutes. Bolus delivery was achieved by encapsulating molecules just within microneedle shafts. For the first time, sustained delivery over hours to days was achieved by encapsulating molecules within the microneedle backing, which served as a controlled release reservoir that delivered molecules by a combination of swelling the backing with interstitial fluid drawn out of the skin and molecule diffusion into the skin via channels formed by dissolved microneedles. We conclude that dissolving microneedles can be designed to gently encapsulate molecules, insert into skin, and enable bolus or sustained release delivery.

  16. Scaling up a Mobile Telemedicine Solution in Botswana: Keys to Sustainability.

    Science.gov (United States)

    Ndlovu, Kagiso; Littman-Quinn, Ryan; Park, Elizabeth; Dikai, Zambo; Kovarik, Carrie L

    2014-01-01

    Effective health care delivery is significantly compromised in an environment where resources, both human and technical, are limited. Botswana's health care system is one of the many in the African continent with few specialized medical doctors, thereby posing a barrier to patients' access to health care services. In addition, the traditional landline and non-robust Information Technology (IT) network infrastructure characterized by slow bandwidth still dominates the health care system in Botswana. Upgrading of the landline IT infrastructure to meet today's health care demands is a tedious, long, and expensive process. Despite these challenges, there still lies hope in health care delivery utilizing wireless telecommunication services. Botswana has recently experienced tremendous growth in the mobile telecommunication industry coupled with an increase in the number of individually owned mobile devices. This growth inspired the Botswana-UPenn Partnership (BUP) to collaborate with local partners to explore using mobile devices as tools to improve access to specialized health care delivery. Pilot studies were conducted across four medical specialties, including radiology, oral medicine, dermatology, and cervical cancer screening. Findings from the studies became vital evidence in support of the first scale-up project of a mobile telemedicine solution in Botswana, also known as "Kgonafalo." Some technical and social challenges were encountered during the initial studies, such as malfunctioning of mobile devices, accidental damage of devices, and cultural misalignment between IT and healthcare providers. These challenges brought about lessons learnt, including a strong need for unwavering senior management support, establishment of solid local public-private partnerships, and efficient project sustainability plans. Sustainability milestones included the development and signing of a Memorandum of Understanding (MOU) between the Botswana government and a private

  17. Translating Sustainability: The Design of a Secondary Charter School

    Science.gov (United States)

    Hodgkinson, Todd Michael

    2011-01-01

    Although numerous efforts have been made to enact the concept of sustainability in schools around the world, a single, replicable model of sustainability education fails to exist. Without a replicable model to follow or adapt, educators looking to enact the concept of sustainability are left to their own devices for deciding what this orientation…

  18. SUSTAINABLE CHEMISTRY FOR SUSTAINABLE INDUSTRY

    Directory of Open Access Journals (Sweden)

    G. Rizzuto

    2015-01-01

    Full Text Available Foundry Alfe Chem is an industrial reality working in the field of lubrication and chemical auxiliaries for industrial processes, which falls within the framework of the emerging and increasingly important «green chemistry». The goal of the company is to develop products that are more environmentally friendly by using raw materials from renewable sources; specifically, Foundry Alfe Chem has a program of self-sustainability that contemplates, for the foreseeable future, the direct production of renewable raw materials. The company has developed a new dedicated product line, Olitema, whose purpose is to offer highly technological solutions with complete environmental sustainability. In this context, Foundry Alfe CHEM has created a new product which represents a breakthrough in the class of HFC hydraulic fluids: Ecosafe Plus is a biodegradable fire-resistant hydraulic fluid with high engineering and technological performances, high environmental sustainability and the best security guarantees in workplaces. Its formulation is glycols-free, and it allows for easier disposal of the exhausted fluid, compared to a traditional water/ glycol-based HFC hydraulic fluid. For what concern the technological properties, Ecosafe Plus has been tested by accredited laboratories with tribological trials (4 Ball wear test ASTM D 4172, Ball on disc test ASTM 6425, Brugger test DIN 51347, Vickers test ASTM D 2882, with elastomer compatibility test (ASTM D 471 and biodegradability test (OECD 310 F.

  19. Incorporating sustainability into accounting curricula

    DEFF Research Database (Denmark)

    Hazelton, James; Haigh, Matthew

    2010-01-01

    This paper chronicles the journey of two projects that sought to incorporate principles of sustainable development into predominantly technical postgraduate accounting curricula. The design and delivery of the projects were informed by Freirian principles of praxis and critical empowerment....... The first author introduced sustainability-related material into a core technical accounting unit and created an elective unit. The second author participated with students to evaluate critically social reports of employers, current and potential. In terms of an objective of bringing reflexivity...... as vocational skills) add to the difficulties for sustainability in penetrating already overcrowded curricula....

  20. Sustainable Procurement

    DEFF Research Database (Denmark)

    Telles, Pedro; Ølykke, Grith Skovgaard

    2017-01-01

    and within it how sustainable requirements have increased the level of compliance required, particularly regulatory compliance. Compliance was already present in previous EU public procurement frameworks, but its extent on Directive 2014/24/EU leads the authors to consider the current legal framework...... as subject to substantial regulatory compliance obligations external to the process of procurement. In short, procurement has been transformed in a way to enforce regulatory obligations that are not intrinsic to the process of buying. This leads to the conclusion that questions such as the cost and trade...

  1. Ferroelectric devices

    CERN Document Server

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  2. Catalytic devices

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Zhang, Xiang

    2018-01-23

    This disclosure provides systems, methods, and apparatus related to catalytic devices. In one aspect, a device includes a substrate, an electrically insulating layer disposed on the substrate, a layer of material disposed on the electrically insulating layer, and a catalyst disposed on the layer of material. The substrate comprises an electrically conductive material. The substrate and the layer of material are electrically coupled to one another and configured to have a voltage applied across them.

  3. Future of Automated Insulin Delivery Systems.

    Science.gov (United States)

    Castle, Jessica R; DeVries, J Hans; Kovatchev, Boris

    2017-06-01

    Advances in continuous glucose monitoring (CGM) have brought on a paradigm shift in the management of type 1 diabetes. These advances have enabled the automation of insulin delivery, where an algorithm determines the insulin delivery rate in response to the CGM values. There are multiple automated insulin delivery (AID) systems in development. A system that automates basal insulin delivery has already received Food and Drug Administration approval, and more systems are likely to follow. As the field of AID matures, future systems may incorporate additional hormones and/or multiple inputs, such as activity level. All AID systems are impacted by CGM accuracy and future CGM devices must be shown to be sufficiently accurate to be safely incorporated into AID. In this article, we summarize recent achievements in AID development, with a special emphasis on CGM sensor performance, and discuss the future of AID systems from the point of view of their input-output characteristics, form factor, and adaptability.

  4. Sustainable consumption and marketing

    NARCIS (Netherlands)

    Dam, van Y.K.

    2016-01-01

    Sustainable development in global food markets is hindered by the discrepancy between positive consumer attitudes towards sustainable development or sustainability and the lack of corresponding sustainable consumption by a majority of consumers. Apparently for many (light user) consumers the

  5. Assisted Vaginal Delivery

    Science.gov (United States)

    ... prescription. If sitting is uncomfortable, sit on a pillow. There also are special cushions that may be ... vagina. Cesarean Delivery: Delivery of a baby through surgical incisions made in the mother’s abdomen and uterus. ...

  6. Sustainable Cities, Sustainable Minds, Sustainable Schools: Pop-Up-Farm as a Connecting Device

    Science.gov (United States)

    Clarke, Paul

    2012-01-01

    This paper argues that modern education is premised upon urban industrial society, and that this has been conceived around a false notion of progress which perpetuates fracture between people and planet. If education maintains this illusion of progress whilst ignoring the reality of environmental meltdown it serves no reliable purpose in…

  7. Bioactive cell-hydrogel microcapsules for cell-based drug delivery.

    Science.gov (United States)

    Orive, Gorka; De Castro, María; Kong, Hyun-Joon; Hernández, Rosa M A; Ponce, Sara; Mooney, David J; Pedraz, José Luis

    2009-05-05

    Improvement of long-term drug release and design of mechanically more stable encapsulation devices are still major challenges in the field of cell encapsulation. This may be in part due to the weak in vivo stability of calcium-alginate beads and to the use of inactive biomaterials and inert scaffolds that do not mimic the physiological situation of the normal cell milieu. We hypothesized that designing biomimetic cell-hydrogel capsules might promote the in vivo long-term functionality of the enclosed drug-secreting cells and improve the mechanical stability of the capsules. Biomimetic capsules were fabricated by coupling the adhesion peptide arginine glycine aspartic acid (RGD) to alginate polymer chains and by using an alginate-mixture providing a bimodal molecular weight distribution. The biomimetic capsules provide cell adhesion for the enclosed cells, potentially also leading to mechanical stabilization of the cell-polymer system. Strikingly, the novel cell-hydrogel system significantly prolonged the in vivo long-term functionality and drug release, providing a sustained erythropoietin delivery during 300 days without immunosuppressive protocols. Additionally, controlling the cell-dose within the biomimetic capsules enables a controlled in vitro and in vivo drug delivery. Biomimetic cell-hydrogel capsules provide a unique microenvironment for the in vivo long-term de novo delivery of drugs from immobilized cells.

  8. System for radiation delivery applied to brachytherapy using a polymeric vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa Junior, Iorque L.; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). PCA 1 - Anexo Engenharia]. E-mail: iorque@eng-nucl.mest.ufmg.br; campos@nuclear.ufmg.br

    2007-07-01

    This work describes a system for radiation delivery applied to brachytherapy using radioactive macroaggregate produced by sol-gel route incorporating Samarium-153 loaded in a polymeric vehicle. The polymer Poly Vinyl Alcohol, PVA, was selected as vehicle. It presents high biocompatibility and is suitable for low temperature handling. The PVA is the water-soluble synthetic resin more produced in the world being used in several applications including controlled drugs delivery. The developed polymeric delivery system is presented as flexible flat surface with a load of macroaggregate in the form of micro seeds or dispersed dust. Such device fits in various brachytherapy applications, especially in interstitial or intracavitary implants and intraoperative radiation therapy. These systems provide mechanical sustainment for the radioactive macroaggregates in well defined spatial distribution improving the conformation of the absorbed dose in the organ or tumor and it can be set up during surgery quickly and safely, reducing the radiation exposition of the medical crew. The degradation time in physiological solution are presented. (author)

  9. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

    Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

  10. Sustainability; Sustentabilidade

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-10-15

    This chapter analyses the production chain of ethanol, considering the impacts on the quality of the air, water supplies, soil occupation and biodiversity, and the efforts for the soil preservation. It is pointed out the activities of the production cycle and use of bio ethanol due to great uncertainties as far the environmental impacts is concerning and that will deserve more attention in future evaluations. At same time, the chapter highlights another activities where the present acknowledge is sufficient to assure the control and/or prediction of consequences of the desired intervention on the environment media to accommodate the sugar and ethanol production expansion. The consideration is not conservative but to promote the sustainable development.

  11. Identification device

    Science.gov (United States)

    Lin, Jian-Shian; Su, Chih-Chieh; Chou, Ta-Hsin; Wu, Mount-Learn; Lai, Chieh-Lung; Hsu, Che-Lung; Lan, Hsiao-Chin; Huang, Hung-I.; Liu, Yung-Chih; Tu, Zong-Ru; Lee, Chien-Chieh; Chang, Jenq-Yang

    2007-09-01

    In this Letter, the identification device disclosed in the present invention is comprised of: a carrier and a plurality of pseudo-pixels; wherein each of the plural pseudo-pixels is formed on the carrier and is further comprised of at least a light grating composed of a plurality of light grids. In a preferred aspect, each of the plural light grids is formed on the carrier while spacing from each other by an interval ranged between 50nm and 900nm. As the aforesaid identification device can present specific colors and patterns while it is being viewed by naked eye with respect to a specific viewing angle, the identification device is preferred for security and anti-counterfeit applications since the specific colors and patterns will become invisible when it is viewed while deviating from the specific viewing angle.

  12. Nasal drug delivery in humans.

    Science.gov (United States)

    Bitter, Christoph; Suter-Zimmermann, Katja; Surber, Christian

    2011-01-01

    Intranasal administration is an attractive option for local and systemic delivery of many therapeutic agents. The nasal mucosa is--compared to other mucosae--easily accessible. Intranasal drug administration is noninvasive, essentially painless and particularly suited for children. Application can be performed easily by patients or by physicians in emergency settings. Intranasal drug delivery offers a rapid onset of therapeutic effects (local or systemic). Nasal application circumvents gastrointestinal degradation and hepatic first-pass metabolism of the drug. The drug, the vehicle and the application device form an undividable triad. Its selection is therefore essential for the successful development of effective nasal products. This paper discusses the feasibility and potential of intranasal administration. A series of questions regarding (a) the intended use (therapeutic considerations), (b) the drug, (c) the vehicle and (d) the application device (pharmaceutical considerations) are addressed with a view to their impact on the development of products for nasal application. Current and future trends and perspectives are discussed. Copyright © 2011 S. Karger AG, Basel.

  13. Sustainability Science Needs Sustainable Data!

    Science.gov (United States)

    Downs, R. R.; Chen, R. S.

    2013-12-01

    Sustainability science (SS) is an 'emerging field of research dealing with the interactions between natural and social systems, and with how those interactions affect the challenge of sustainability: meeting the needs of present and future generations while substantially reducing poverty and conserving the planet's life support systems' (Kates, 2011; Clark, 2007). Bettencourt & Kaur (2011) identified more than 20,000 scientific papers published on SS topics since the 1980s with more than 35,000 distinct authors. They estimated that the field is currently growing exponentially, with the number of authors doubling approximately every 8 years. These scholars are undoubtedly using and generating a vast quantity and variety of data and information for both SS research and applications. Unfortunately we know little about what data the SS community is actually using, and whether or not the data that SS scholars generate are being preserved for future use. Moreover, since much SS research is conducted by cross-disciplinary, multi-institutional teams, often scattered around the world, there could well be increased risks of data loss, reduced data quality, inadequate documentation, and poor long-term access and usability. Capabilities and processes therefore need to be established today to support continual, reliable, and efficient preservation of and access to SS data in the future, especially so that they can be reused in conjunction with future data and for new studies not conceived in the original data collection activities. Today's long-term data stewardship challenges include establishing sustainable data governance to facilitate continuing management, selecting data to ensure that limited resources are focused on high priority SS data holdings, securing sufficient rights to allow unforeseen uses, and preparing data to enable use by future communities whose specific research and information needs are not yet known. Adopting sustainable models for archival

  14. Drug Delivery Research: The Invention Cycle.

    Science.gov (United States)

    Park, Kinam

    2016-07-05

    Controlled drug delivery systems have been successful in introducing improved formulations for better use of existing drugs and novel delivery of biologicals. The initial success of producing many oral products and some injectable depot formulations, however, reached a plateau, and the progress over the past three decades has been slow. This is likely due to the difficulties of formulating hydrophilic, high molecular weight drugs, such as proteins and nucleic acids, for targeting specific cells, month-long sustained delivery, and pulsatile release. Since the approaches that have served well for delivery of small molecules are not applicable to large molecules, it is time to develop new methods for biologicals. The process of developing future drug delivery systems, termed as the invention cycle, is proposed, and it starts with clearly defining the problems for developing certain formulations. Once the problems are well-defined, creative imagination examines all potential options and selects the best answer and alternatives. Then, innovation takes over to generate unique solutions for developing new formulations that resolve the previously identified problems. Ultimately, the new delivery systems will have to go through a translational process to produce the final formulations for clinical use. The invention cycle also emphasizes examining the reasons for success of certain formulations, not just the reasons for failure of many systems. Implementation of the new invention cycle requires new mechanisms of funding the younger generation of scientists and a new way of identifying their achievements, thereby releasing them from the burden of short-termism.

  15. Sustainability and transformation plans: translating the perspectives.

    Science.gov (United States)

    Thakrar, Sonali V; Bell, Diane

    2017-10-02

    Each local health economy has been tasked with producing a sustainability and transformation plan. A health economy is a system that controls and contributes to health-care resource and the effects of health services on its population. This includes commissioners, acute providers, primary care providers, community services, public health and the voluntary sector. Sustainability and transformation plans represent a shift in the way health care is planned for in England. The aim of each sustainability and transformation plan is to deliver care within existing resource limits by improving quality of care, developing new models of care and improving efficiency of care provision. The tight timescales for production of sustainability and transformation plans mean that in most cases there has been limited clinical engagement; as a result many clinicians have limited sight, understanding or ownership of the proposals within sustainability and transformation plans. As sustainability and transformation plans move into the implementation phase, this article explores the role of the clinician in the ongoing design and delivery of the local sustainability and transformation plans. By finding the common ground between the perspectives of the clinician, the commissioner and system leaders, the motivation of clinicians can be aligned with the ambitions of the sustainability and transformation plan. The common goal of a sustainability and transformation plan and the necessary collaboration required to make it successful is discussed. Ultimately, such translation is essential: clinicians are intelligent, adaptive and motivated individuals who must have a lead role in constructing and implementing plans that transform health and social care.

  16. UAV Delivery Monitoring System

    Directory of Open Access Journals (Sweden)

    San Khin Thida

    2018-01-01

    Full Text Available UAV-based delivery systems are increasingly being used in the logistics field, particularly to achieve faster last-mile delivery. This study develops a UAV delivery system that manages delivery order assignments, autonomous flight operation, real time control for UAV flights, and delivery status tracking. To manage the delivery item assignments, we apply the concurrent scheduler approach with a genetic algorithm. The present paper describes real time flight data based on a micro air vehicle communication protocol (MAVLink. It also presents the detailed hardware components used for the field tests. Finally, we provide UAV component analysis to choose the suitable components for delivery in terms of battery capacity, flight time, payload weight and motor thrust ratio.

  17. A Microfluidic Ion Pump for In Vivo Drug Delivery

    KAUST Repository

    Uguz, Ilke

    2017-05-15

    Implantable devices offer an alternative to systemic delivery of drugs for the treatment of neurological disorders. A microfluidic ion pump (µFIP), capable of delivering a drug without the solvent through electrophoresis, is developed. The device is characterized in vitro by delivering γ-amino butyric acid to a target solution, and demonstrates low-voltage operation, high drug-delivery capacity, and high ON/OFF ratio. It is also demonstrated that the device is suitable for cortical delivery in vivo by manipulating the local ion concentration in an animal model and altering neural behavior. These results show that µFIPs represent a significant step forward toward the development of implantable drug-delivery systems.

  18. Dissolving Microneedles for Transdermal Drug Delivery

    OpenAIRE

    Lee, Jeong Woo; Park, Jung-Hwan; Prausnitz, Mark R.

    2008-01-01

    Microfabrication technology has been adapted to produce micron-scale needles as a safer and painless alternative to hypodermic needle injection, especially for protein biotherapeutics and vaccines. This study presents a design that encapsulates molecules within microneedles that dissolve within the skin for bolus or sustained delivery and leave behind no biohazardous sharp medical waste. A fabrication process was developed based on casting a viscous aqueous solution during centrifugation to f...

  19. Detection device

    Science.gov (United States)

    Smith, J.E.

    1981-02-27

    The present invention is directed to a detection device comprising: (1) an entrance chamber; (2) a central chamber; and (3) an exit chamber. The central chamber includes an ionizing gas, anode, and means for connecting the anode with an external power supply and pulse counter.

  20. Medical Devices

    NARCIS (Netherlands)

    Verkerke, Gijsbertus Jacob; Mahieu, H.F.; Geertsema, A.A.; Hermann, I.F.; van Horn, J.R.; Hummel, J. Marjan; van Loon, J.P.; Mihaylov, D.; van der Plaats, A.; Schraffordt Koops, H.; Schutte, H.K.; Veth, R.P.H.; de Vries, M.P.; Rakhorst, G.; Shi, Donglu

    2004-01-01

    The development of new medical devices is a very time-consuming and costly process. Besides the time between the initial idea and the time that manufacturing and testing of prototypes takes place, the time needed for the development of production facilities, production of test series, marketing,

  1. Printing Device

    NARCIS (Netherlands)

    Berg, van den M.J.; Markies, P.R.; Zuilhof, H.

    2014-01-01

    An ink jetprinting device includes a pressure chamber formed by a plurality of wall segments, a first aperture extending through a wall segment and communicating with an ink jet orifice and a second aperture extending through a wall segment and communicating with an ink supply duct. The pressure

  2. Future options for aerosol delivery to children

    DEFF Research Database (Denmark)

    Bisgaard, H

    1999-01-01

    , allowing less compliant children enough time to obtain a full dose. Eliminating the electrostatic charge can change the lung dose by several times; hence, nonelectrostatic materials should be used in future spacer devices. Compliance is the biggest problem in drug delivery to children. The inhaler design......There is an increasing awareness of the importance of reliable aerosol delivery, with emphasis on the dose delivered to the lungs, optimal clinical control, cost-effectiveness, and safety in children. Dose prescription should relate to the expected lung dose rather than the factory-dispensed dose....... Such features should improve our ability to treat young children with inhaled drug aerosols....

  3. Sustainable Scientists

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Evan

    2008-12-31

    Scientists are front and center in quantifying and solving environmental problems. Yet, as a spate of recent news articles in scientific journals point out, much can be done to enhance sustainability within the scientific enterprise itself, particularly by trimming the energy use associated with research facilities and the equipment therein (i,ii,iii, iv). Sponsors of research unwittingly spend on the order of $10 billion each year on energy in the U.S. alone, and the underlying inefficiencies drain funds from the research enterprise while causing 80 MT CO2-equivalent greenhouse-gas emissions (see Box). These are significant sums considering the opportunity costs in terms of the amount of additional research that could be funded and emissions that could be reduced if the underlying energy was used more efficiently. By following commercially proven best practices in facility design and operation, scientists--and the sponsors of science--can cost-effectively halve these costs, while doing their part to put society on alow-carbon diet.

  4. Nanoparticle-based drug delivery to the vagina: a review

    Science.gov (United States)

    Ensign, Laura M.; Cone, Richard; Hanes, Justin

    2014-01-01

    Vaginal drug administration can improve prophylaxis and treatment of many conditions affecting the female reproductive tract, including sexually transmitted diseases, fungal and bacterial infections, and cancer. However, achieving sustained local drug concentrations in the vagina can be challenging, due to the high permeability of the vaginal epithelium and expulsion of conventional soluble drug dosage forms. Nanoparticle-based drug delivery platforms have received considerable attention for vaginal drug delivery, as nanoparticles can provide sustained release, cellular targeting, and even intrinsic antimicrobial or adjuvant properties that can improve the potency and/or efficacy of prophylactic and therapeutic modalities. Here, we review the use of polymeric nanoparticles, liposomes, dendrimers, and inorganic nanoparticles for vaginal drug delivery. Although most of the work toward nanoparticle-based drug delivery in the vagina has been focused on HIV prevention, strategies for treatment and prevention of other sexually transmitted infections, treatment for reproductive tract cancer, and treatment of fungal and bacterial infections are also highlighted. PMID:24830303

  5. Sustainable agriculture - selected papers

    OpenAIRE

    Krasowicz, Stanisław; Wrzaszcz, Wioletta; Zegar, Jozef St.

    2007-01-01

    The concept of research on socially sustainable agriculture. Features of sustainable agriculture. Sustainability of private farms in the light of selected criteria. Subsistence agricultural holdings and the sustainable development of agriculture. Sustainable farms in the light of the FADN data. Description of organic holdings in Poland.

  6. Exploring Newly Introduced Methods for Testing MDIs with Add-On Devices

    National Research Council Canada - National Science Library

    Mark Copley

    2014-01-01

      In an interview, Mark Copley, sales director of Copley Scientific, provides expert insight on why add-on devices are used, how these devices impact drug delivery with a pressurized metered dose inhalers (pMDI...

  7. Hopi Sustainable Energy Plan

    Energy Technology Data Exchange (ETDEWEB)

    Norman Honie, Jr.; Margie Schaff; Mark Hannifan

    2004-08-01

    The Hopi Tribal Government as part of an initiative to ?Regulate the delivery of energy and energy services to the Hopi Reservation and to create a strategic business plan for tribal provision of appropriate utility, both in a manner that improves the reliability and cost efficiency of such services,? established the Hopi Clean Air Partnership Project (HCAPP) to support the Tribe?s economic development goals, which is sensitive to the needs and ways of the Hopi people. The Department of Energy (DOE) funded, Formation of Hopi Sustainable Energy Program results are included in the Clean Air Partnership Report. One of the Hopi Tribe?s primary strategies to improving the reliability and cost efficiency of energy services on the Reservation and to creating alternative (to coal) economic development opportunities is to form and begin implementation of the Hopi Sustainable Energy Program. The Hopi Tribe through the implementation of this grant identified various economic opportunities available from renewable energy resources. However, in order to take advantage of those opportunities, capacity building of tribal staff is essential in order for the Tribe to develop and manage its renewable energy resources. As Arizona public utilities such as APS?s renewable energy portfolio increases the demand for renewable power will increase. The Hopi Tribe would be in a good position to provide a percentage of the power through wind energy. It is equally important that the Hopi Tribe begin a dialogue with APS and NTUA to purchase the 69Kv transmission on Hopi and begin looking into financing options to purchase the line.

  8. Bioadhesive delivery systems for mucosal vaccine delivery.

    Science.gov (United States)

    Baudner, Barbara C; O'Hagan, Derek T

    2010-12-01

    Mucosal vaccine delivery potentially induces mucosal as well as systemic immune responses and may have advantages particularly for optimal protection against pathogens that infect the host through mucosal surfaces. However, the delivery of antigens through mucosal membranes remains a major challenge due to unfavorable physiological conditions (pH and enzymes) and significant biological barriers, which restrict the uptake of antigens. To improve mucosal vaccine delivery, the use of bioadhesive delivery systems offers numerous advantages, including protection from degradation, increasing concentration of antigen in the vicinity of mucosal tissue for better absorption, extending their residence time, and/or targeting them to sites of antigen uptake. Although some bioadhesives have direct immune stimulating properties, it appears most likely that successful mucosal vaccination will require the addition of vaccine adjuvants for optimal immune responses, particularly if they are to be used in an unprimed population. Thus, complex vaccine formulations and delivery strategies have to be carefully designed to appropriately stimulate immune response for the target pathogen. In addition, careful consideration is needed to define the "best" route for mucosal immunization for each individual pathogen.

  9. Laser device

    Science.gov (United States)

    Scott, Jill R.; Tremblay, Paul L.

    2008-08-19

    A laser device includes a virtual source configured to aim laser energy that originates from a true source. The virtual source has a vertical rotational axis during vertical motion of the virtual source and the vertical axis passes through an exit point from which the laser energy emanates independent of virtual source position. The emanating laser energy is collinear with an orientation line. The laser device includes a virtual source manipulation mechanism that positions the virtual source. The manipulation mechanism has a center of lateral pivot approximately coincident with a lateral index and a center of vertical pivot approximately coincident with a vertical index. The vertical index and lateral index intersect at an index origin. The virtual source and manipulation mechanism auto align the orientation line through the index origin during virtual source motion.

  10. Project delivery system (PDS)

    CERN Document Server

    2001-01-01

    As business environments become increasingly competitive, companies seek more comprehensive solutions to the delivery of their projects. "Project Delivery System: Fourth Edition" describes the process-driven project delivery systems which incorporates the best practices from Total Quality and is aligned with the Project Management Institute and ISO Quality Standards is the means by which projects are consistently and efficiently planned, executed and completed to the satisfaction of clients and customers.

  11. "Distinvar" device

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.

  12. Sustainable NREL - Site Sustainability Plan FY 2015

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-01-01

    NREL's Site Sustainability Plan FY 2015 reports on sustainability plans for the lab for the year 2015 based on Executive Order Goals and provides the status on planned actions cited in the FY 2014 report.

  13. Transdermal Delivery of Drugs with Microneedles—Potential and Challenges

    OpenAIRE

    Kevin Ita

    2015-01-01

    Transdermal drug delivery offers a number of advantages including improved patient compliance, sustained release, avoidance of gastric irritation, as well as elimination of pre-systemic first-pass effect. However, only few medications can be delivered through the transdermal route in therapeutic amounts. Microneedles can be used to enhance transdermal drug delivery. In this review, different types of microneedles are described and their methods of fabrication highlighted. Microneedles can be ...

  14. Comparison of chitosan nanoparticles and chitosan hydrogels for vaccine delivery

    DEFF Research Database (Denmark)

    Gordon, Sarah; Saupe, Anne; McBurney, Warren

    2008-01-01

    In this work the potential of chitosan nanoparticles (CNP) and thermosensitive chitosan hydrogels as particulate and sustained release vaccine delivery systems was investigated. CNP and chitosan hydrogels were prepared, loaded with the model protein antigen ovalbumin (OVA) and characterised....... The immunostimulatory capacity of these vaccine delivery systems was assessed in-vitro and in-vivo. Particle sizing measurements and SEM images showed that optimised OVA-loaded CNP had a size of approximately 200 nm, a polydispersity index

  15. Primary Control by ON/OFF Demand-Side Devices

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Hansen, Lars Henrik; Andersen, Palle

    2013-01-01

    manage the portfolio of devices to collectively provide a primary reserve delivery in an unbundled liberalized electricity market setting under current regulations. Furthermore, we formulate a binary linear optimization problem that minimizes the aggregator’s cost of providing a primary reserve delivery......We consider an aggregator managing a portfolio of ON/OFF demand-side devices. The devices are able to shift con- sumption in time within certain energy limitations; moreover, the devices are able to measure the system frequency and switch ON and OFF accordingly. We show how the aggregator can...

  16. Advanced Mechatronics and MEMS Devices

    CERN Document Server

    2013-01-01

    Advanced Mechatronics and MEMS Devicesdescribes state-of-the-art MEMS devices and introduces the latest technology in electrical and mechanical microsystems. The evolution of design in microfabrication, as well as emerging issues in nanomaterials, micromachining, micromanufacturing and microassembly are all discussed at length in this volume. Advanced Mechatronics also provides a reader with knowledge of MEMS sensors array, MEMS multidimensional accelerometer, artificial skin with imbedded tactile components, as well as other topics in MEMS sensors and transducers. The book also presents a number of topics in advanced robotics and an abundance of applications of MEMS in robotics, like reconfigurable modular snake robots, magnetic MEMS robots for drug delivery and flying robots with adjustable wings, to name a few. This book also: Covers the fundamentals of advanced mechatronics and MEMS devices while also presenting new state-of-the-art methodology and technology used in the application of these devices Prese...

  17. Sustainability in Transport Planning

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik; Greve, Carsten

    Contribution to session J: Joint University Sustainability Initiatives. This session will provide an inspiring overview of interdisciplinary research and teaching activities on sustainability bridging DTU, KU, and CBS, and introduce the joint collaboration Copenhagen Sustainability Initiative (COSI...

  18. Sustainability : Politics and governance

    NARCIS (Netherlands)

    Heinrichs, Harald; Biermann, Frank

    2016-01-01

    he article gives an overview of global sustainability policy and politics. It is shown how international policy making on sustainable development has progressed from environmental policy toward recent approaches of Earth system governance. Key challenges of international sustainability politics are

  19. Textiles and clothing sustainability sustainable technologies

    CERN Document Server

    2017-01-01

    This is the first book to deal with the innovative technologies in the field of textiles and clothing sustainability. It details a number of sustainable and innovative technologies and highlights their implications in the clothing sector. There are currently various measures to achieve sustainability in the textiles and the clothing industry, including innovations in the manufacturing stage, which is the crux of this book.

  20. Controlling fungal biofilms with functional drug delivery denture biomaterials.

    Science.gov (United States)

    Wen, Jianchuan; Jiang, Fuguang; Yeh, Chih-Ko; Sun, Yuyu

    2016-04-01

    Candida-associated denture stomatitis (CADS), caused by colonization and biofilm-formation of Candida species on denture surfaces, is a significant clinical concern. We show here that modification of conventional denture materials with functional groups can significantly increase drug binding capacity and control drug release rate of the resulting denture materials for potentially managing CADS. In our approach, poly(methyl methacrylate) (PMMA)-based denture resins were surface grafted with three kinds of polymers, poly(1-vinyl-2-pyrrolidinone) (PNVP), poly(methacrylic acid) (PMAA), and poly(2-hydroxyethyl methacrylate) (PHEMA), through plasma-initiated grafting polymerization. With a grafting yield as low as 2 wt%, the three classes of new functionalized denture materials showed significantly higher drug binding capacities toward miconazole, a widely used antifungal drug, than the original PMMA denture resin control, leading to sustained drug release and potent biofilm-controlling effects against Candida. Among the three classes of functionalized denture materials, PNVP-grafted resin provided the highest miconazole binding capability and the most powerful antifungal and biofilm-controlling activities. Drug binding mechanisms were studied. These results demonstrated the importance of specific interactions between drug molecules and functional groups on biomaterials, shedding lights on future design of CADS-managing denture materials and other related devices for controlled drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Microneedle and mucosal delivery of influenza vaccines

    Science.gov (United States)

    Kang, Sang-Moo; Song, Jae-Min; Kim, Yeu-Chun

    2017-01-01

    In recent years with the threat of pandemic influenza and other public health needs, alternative vaccination methods other than intramuscular immunization have received great attention. The skin and mucosal surfaces are attractive sites probably because of both non-invasive access to the vaccine delivery and unique immunological responses. Intradermal vaccines using a microinjection system (BD Soluvia) and intranasal vaccines (FluMist) are licensed. As a new vaccination method, solid microneedles have been developed using a simple device that may be suitable for self-administration. Because coated micorneedle influenza vaccines are administered in the solid state, developing formulations maintaining the stability of influenza vaccines is an important issue to be considered. Marketable microneedle devices and clinical trials remain to be developed. Other alternative mucosal routes such as oral and intranasal delivery systems are also attractive for inducing cross protective mucosal immunity but effective non-live mucosal vaccines remain to be developed. PMID:22697052

  2. Thiolated polymers as mucoadhesive drug delivery systems.

    Science.gov (United States)

    Duggan, Sarah; Cummins, Wayne; O' Donovan, Orla; Hughes, Helen; Owens, Eleanor

    2017-03-30

    Mucoadhesion is the process of binding a material to the mucosal layer of the body. Utilising both natural and synthetic polymers, mucoadhesive drug delivery is a method of controlled drug release which allows for intimate contact between the polymer and a target tissue. It has the potential to increase bioavailability, decrease potential side effects and offer protection to more sensitive drugs such as proteins and peptide based drugs. The thiolation of polymers has, in the last number of years, come to the fore of mucoadhesive drug delivery, markedly improving mucoadhesion due to the introduction of free thiol groups onto the polymer backbone while also offering a more cohesive polymeric matrix for the slower and more controlled release of drug. This review explores the concept of mucoadhesion and the recent advances in both the polymers and the methods of thiolation used in the synthesis of mucoadhesive drug delivery devices. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Prediction of preterm delivery

    NARCIS (Netherlands)

    Wilms, F.F.

    2014-01-01

    Preterm delivery is in quantity and in severity an important issue in the obstetric care in the Western world. There is considerable knowledge on maternal and obstetric risk factors of preterm delivery. Of the women presenting with preterm labor, the majority is pregnant with a male fetus and in

  4. [The moon and delivery].

    Science.gov (United States)

    Romero Martínez, Jorge; Guerrero Guijo, Inmaculada; Artura Serrano, Antonio

    2004-11-01

    In different cultures and mythologies, the moon is related with fertility, pregnancy and delivery. Professional obstetricians also notice an increase in care demands on the days when the moon is full. Many studies have been made which try to correlate delivery processes to the phases of the moon with contradictory results. The authors plan to try to find any basis in fact which support these popular beliefs and to discover if lunar phases bear an influence on the distribution of deliveries. They carried out a descriptive transversal study on a total of 1715 unassisted deliveries over the course of ten complete lunar cycles. The authors have carried out a descriptive and inferential analysis, a one way ANOVA and a Kruskal Wallis test on their three data bases which are general, primipara and multipara in which they contemplated the total number of deliveries per phase, the mean of each phase, as well as the central day in each phase of the lunar cycle. The differences found in the distribution of deliveries over the four lunar phases, along with the comparison of the means and the comparison of the number of deliveries on the central day in each phase are not statistically significant. The different phases in the lunar cycle and especially the full moon do not appear to have any influence over the distribution of deliveries in this study.

  5. Global Delivery Models

    DEFF Research Database (Denmark)

    Manning, Stephan; Larsen, Marcus M.; Bharati, Pratyush

    2013-01-01

    This article examines antecedents and performance implications of global delivery models (GDMs) in global business services. GDMs require geographically distributed operations to exploit both proximity to clients and time-zone spread for efficient service delivery. We propose and empirically show...

  6. Micromachined therapeutic delivery systems: from concept to clinic

    Science.gov (United States)

    Desai, Tejal A.

    2001-05-01

    Microfabrication techniques which permit the creation of therapeutic delivery systems that possess a combination of structural, mechanical, and perhaps electronic features may surmount challenges associated with conventional delivery of therapy. In this review, delivery concepts are presented which capitalize on the strengths of microfabrication. Possible applications include micromachined silicon membranes to create implantable biocapsules for the immunoisolation of pancreatic islet cells--as a possible treatment for diabetes--and sustained release of injectable drugs needed over long time periods. Asymmetrical, drug- loaded microfabricated particles with specific ligands linked to the surface are proposed for improving oral bioavailability of peptide (and perhaps protein) drugs.

  7. Developing a comprehensive definition of sustainability.

    Science.gov (United States)

    Moore, Julia E; Mascarenhas, Alekhya; Bain, Julie; Straus, Sharon E

    2017-09-02

    Understanding sustainability is one of the significant implementation science challenges. One of the big challenges in researching sustainability is the lack of consistent definitions in the literature. Most implementation studies do not present a definition of sustainability, even when assessing sustainability. The aim of the current study was to systematically develop a comprehensive definition of sustainability based on definitions already used in the literature. We searched for knowledge syntheses of sustainability and abstracted sustainability definitions from the articles identified through any relevant systematic and scoping reviews. The constructs in the abstracted sustainability definitions were mapped to an existing definition. The comprehensive definition of sustainability was revised to include emerging constructs. We identified four knowledge syntheses of sustainability, which identified 209 original articles. Of the 209 articles, 24 (11.5%) included a definition of sustainability. These definitions were mapped to three constructs from an existing definition, and nine new constructs emerged. We reviewed all constructs and created a revised definition: (1) after a defined period of time, (2) a program, clinical intervention, and/or implementation strategies continue to be delivered and/or (3) individual behavior change (i.e., clinician, patient) is maintained; (4) the program and individual behavior change may evolve or adapt while (5) continuing to produce benefits for individuals/systems. All 24 definitions were remapped to the comprehensive definition (percent agreement among three coders was 94%). Of the 24 definitions, 17 described the continued delivery of a program (70.8%), 17 mentioned continued outcomes (70.8%), 13 mentioned time (54.2%), 8 addressed the individual maintenance of a behavior change (33.3%), and 6 described the evolution or adaptation (25.0%). We drew from over 200 studies to identify 24 existing definitions of sustainability

  8. Radiation crosslinked hydrogels as sustained release drug delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Pekala, W.; Rosiak, J.; Rucinska-Rybus, A.; Burczak, K.; Galant, S.; Czolczynska, T.

    1986-01-01

    Radiation methods have been used for: i/modification of vascular prostheses, ii/ obtaining burn dressing materials enabling controlled drug release, iii/ the preparation of polymer ocular insert discs. The surface of polyester vascular prostheses, has been modified by deposition of acrylamide and inducing its polymerization in the solid state by ..gamma..-radiation. As a result of this treatment, tightness of the prosthesis walls and its surface hydrophilicity have been improved. Toxicological examinations and blood hemolysis studies of modified prostheses showed its good biocompatibility. Various burn dressings have been prepared and the most promising of all investigated turned to be composition consisting of a cotton gauze base and an active polyacrylamide hydrogel layer with addition of glycerin and immobilized Provital/protein preparation/. Preliminary clinical evaluations of this particular dressing showed that the process of burn healing is indeed fast and fully satisfactory. Ocular insert discs made of polymer and containing pilocarpin hydrochloride which is released at controlled rate have been prepared. It has been found that high hydrophilicity and good swelling properties of the ocular insert discs made possible to incorporate pilocarpin hydrochloride into hydrogel matrix. This work has been carried out under IAEA research contract RB 3379/R-1 POL.

  9. Radiation crosslinked hydrogels as sustained release drug delivery systems

    Science.gov (United States)

    Pȩkala, W.; Rosiak, J.; Rucińska-Rybus, A.; Burczak, K.; Galant, S.; Czołlczyńska, T.

    Radiation methods have been used for: i/ modification of vascular prostheses, ii/ obtaining burn dressing materials enabling controlled drug release, iii/ the preparation of polymer ocular insert discs. The surface of polyester vascular prostheses, has been modified by deposition of acrylamide and inducing its polymerization in the solid state by j-radiation. As a result of this treatment, tightness of the prosthesis walls and its surface hydrophilicity have been improved. Toxicological examinations and blood hemolysis studies of modified prostheses showed its good biocompatibility. Various burn dressings have been prepared and the most promising of all investigated turned to be composition consisting of a cotton gauze base and an active polyacrylamide hydrogel layer with addition of glycerin and immobilized Provital /protein preparation/. Preliminary clinical evaluations of this particular dressing showed that the process of burn healing is indeed fast and fully satisfactory. Ocular insert discs made of polymer and containing pilocarpin hydrochloride which is released at controlled rate have been prepared. It has been found that high hydrophilicity and good swelling properties of the ocular insert discs made possible to incorporate pilocarpin hydrochloride into the hydrogel matrix. This work has been carried out under IAEA research contract RB 3379/R-1 POL.

  10. Soft contact lenses capable of sustained delivery of timolol.

    Science.gov (United States)

    Alvarez-Lorenzo, Carmen; Hiratani, Haruyiki; Gómez-Amoza, José Luis; Martínez-Pacheco, Ramón; Souto, Consuelo; Concheiro, Angel

    2002-10-01

    The aim of this work was to evaluate the influence of the composition and the application of an imprinting technique on the loading capability of weakly crosslinked hydroxyethyl methacrylate (HEMA) hydrogels, with a view to their use as reloadable soft contact lenses for administration of timolol. Hydrogels were prepared by dissolution of ethylene glycol dimethacrylate (EGDMA, 10 mM) in HEMA with or without methacrylic acid (MAA) or methyl methacrylate (MMA; 100-400 mM) and with or without timolol maleate (10 mg/mL), initiation of polymerization by addition of 2,2'-azo-bis(isobutyronitrile) (AIBN, 10 mM), injection in molds, and curing in an oven at 50-70 degrees C. Unreacted reagents were removed by boiling. The dry hydrogels were clear and fully polymerized with smooth, poreless surfaces and presented optimal mechanical properties. The hydrogels were then characterized by determination of their swelling and timolol release kinetics in 0.9% NaCl, phosphate buffer (pH 7.4) and artificial lacrimal fluid, and of the timolol loading capacity of both nonimprinted hydrogels and de-timololized imprinted hydrogels at various pHs. Both water uptake and timolol release exhibited Fickian kinetics, except in the case of hydrogels made with 400 mM MAA. Timolol diffusion into 0.9% NaCl from HEMA or HEMA/MMA was slow; release from HEMA/MAA into phosphate buffer or lacrimal fluid was faster and increased with the MAA content of the polymer. Timolol loading was significant for HEMA/MAA hydrogels (imprinted or not) at pH 5.5-7.5, and specially for imprinted hydrogels containing 100 mM MAA, which absorb 12 mg timolol/g dry hydrogel. The results indicate that the incorporation of MAA as comonomer increases the timolol loading capacity to therapeutically useful levels while retaining appropriate release characteristics. Copyright 2002 Wiley-Liss Inc. and the American Pharmaceutical Association

  11. Water and sanitation committees for sustainable service delivery in ...

    African Journals Online (AJOL)

    The achievement of the targets in terms of water and sanitation coverage in Ghana depends to a large extent on the establishment of institutions like Water and Sanitation Committees (WATSAN) for effective operation and maintenance of the water and sanitation facilities. This paper is based on the assessment of WATSAN ...

  12. The Sustainable Energy Utility (SEU) Model for Energy Service Delivery

    Science.gov (United States)

    Houck, Jason; Rickerson, Wilson

    2009-01-01

    Climate change, energy price spikes, and concerns about energy security have reignited interest in state and local efforts to promote end-use energy efficiency, customer-sited renewable energy, and energy conservation. Government agencies and utilities have historically designed and administered such demand-side measures, but innovative…

  13. Ultrasound-mediated nail drug delivery system.

    Science.gov (United States)

    Abadi, Danielle; Zderic, Vesna

    2011-12-01

    A novel ultrasound-mediated drug delivery system has been developed for treatment of a nail fungal disorder (onychomycosis) by improving delivery to the nail bed using ultrasound to increase the permeability of the nail. The slip-in device consists of ultrasound transducers and drug delivery compartments above each toenail. The device is connected to a computer, where a software interface allows users to select their preferred course of treatment. In in vitro testing, canine nails were exposed to 3 energy levels (acoustic power of 1.2 W and exposure durations of 30, 60, and 120 seconds). A stereo -microscope was used to determine how much of a drug-mimicking compound was delivered through the nail layers by measuring brightness on the cross section of each nail tested at each condition, where brightness level decreases coincide with increases in permeability. Each of the 3 energy levels tested showed statistical significance when compared to the control (P permeability factor of 1.3 after 30 seconds of exposure, 1.3 after 60 seconds, and 1.5 after 120 seconds, where a permeability factor of 1 shows no increase in permeability. Current treatments for onychomycosis include systemic, topical, and surgical. Even when used all together, these treatments typically take a long time to result in nail healing, thus making this ultrasound-mediated device a promising alternative.

  14. Thermosensitive hydrogels a versatile concept adapted to vaginal drug delivery.

    Science.gov (United States)

    Taurin, Sebastien; Almomen, Aliyah A; Pollak, Tatianna; Kim, Sun Jin; Maxwell, John; Peterson, C Matthew; Owen, Shawn C; Janát-Amsbury, Margit M

    2017-11-15

    Vaginal drug delivery represents an attractive strategy for local and systemic delivery of drugs otherwise poorly absorbed after oral administration. The rather dense vascular network, mucus permeability and the physiological phenomenon of the uterine first-pass effect can all be exploited for therapeutic benefit. However, several physiological factors such as an acidic pH, constant secretion, and turnover of mucus as well as varying thickness of the vaginal epithelium can impact sustained drug delivery. In recent years, polymers have been designed to tackle challenges mentioned above. In particular, thermosensitive hydrogels hold great promise due to their stability, biocompatibility, adhesion properties and adjustable drug release kinetics. Here, we discuss the physiological and anatomical uniqueness of the vaginal environment and how it impacts the safe and efficient vaginal delivery and also reviewed several thermosensitive hydrogels deemed suitable for vaginal drug delivery by addressing specific characteristics, which are essential to engage the vaginal environment successfully.

  15. Scalable devices

    KAUST Repository

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.