Effect of TheraCyte-encapsulated parathyroid cells on lumbar fusion in a rat model

OpenAIRE

Chen, Sung-Hsiung; Huang, Shun-Chen; Lui, Chun-Chung; Lin, Tzu-Ping; Chou, Fong-Fu; Ko, Jih-Yang

2012-01-01

Introduction Implantation of TheraCyte 4 × 106 live parathyroid cells can increase the bone marrow density of the spine of ovariectomized rats. There has been no published study examining the effect of such implantation on spinal fusion outcomes. The purpose of this study was to examine the effect of TheraCyte-encapsulated parathyroid cells on posterolateral lumbar fusions in a rat model. Materials and methods Forty Sprague-Dawley rats underwent single-level, intertransverse process spinal fu...

Sepsis-induced alteration in T-cell Ca(2+) signaling in neonatal rats.

Science.gov (United States)

Alattar, M H; Ravindranath, T M; Choudhry, M A; Muraskas, J K; Namak, S Y; Dallal, O; Sayeed, M M

2001-01-01

Sepsis-induced suppression in T-cell proliferation follows deranged Ca(2+) signaling in adult rats. In preliminary studies, we observed suppression in T-cell proliferation in septic neonatal rats as well. In this study, we assessed splenic T-cell cytosolic Ca(2+) concentration, [Ca(2+)](i), as its elevation plays an important role in T-cell proliferation. Also, we investigated the role of PGE(2) in sepsis-related changes in T-cell [Ca(2+)](i) in animals pretreated with cyclooxygenase-1 (COX-1) inhibitor (resveratrol) and cyclooxygenase-2 (COX-2) inhibitor (NS-398). Sepsis was induced in 15-day-old rat pups by intraperitoneal implantation of fecal pellets containing Escherichia coli and Bacteroides fragilis. The sham group consisted of pups implanted with sterile fecal pellets. Septic and sham pups were sacrificed 24 h after implantation and their spleens were removed. The spleens from sham and septic pups, along with spleens from unoperated control pups, were processed for single cell suspensions, and T cells were isolated using nylon wool columns. Fura-2 fluorophotometry was employed for the measurement of [Ca(2+)](i) (in nM units) in T cells stimulated with concanavalin A (ConA). Our results show that ConA-mediated T-cell [Ca(2+)](i) response is significantly suppressed in septic neonatal rats. Pretreatment of pups with COX-2, but not COX-1 inhibitor, prevented the decrease in the [Ca(2+)](i) response. These findings suggest that PGE(2) might induce the attenuation in T-cell Ca(2+) signaling during sepsis in neonatal rats. Copyright 2001 S. Karger AG, Basel

Monitoring of implanted stem cell migration in vivo: A highly resolved in vivo magnetic resonance imaging investigation of experimental stroke in rat

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Hoehn, Mathias; Küstermann, Ekkehard; Blunk, James; Wiedermann, Dirk; Trapp, Thorsten; Wecker, Stefan; Föcking, Melanie; Arnold, Heinz; Hescheler, Jürgen; Fleischmann, Bernd K.; Schwindt, Wolfram; Bührle, Christian

2002-01-01

In vivo monitoring of stem cells after grafting is essential for a better understanding of their migrational dynamics and differentiation processes and of their regeneration potential. Migration of endogenous or grafted stem cells and neurons has been described in vertebrate brain, both under normal conditions from the subventricular zone along the rostral migratory stream and under pathophysiological conditions, such as degeneration or focal cerebral ischemia. Those studies, however, relied on invasive analysis of brain sections in combination with appropriate staining techniques. Here, we demonstrate the observation of cell migration under in vivo conditions, allowing the monitoring of the cell dynamics within individual animals, and for a prolonged time. Embryonic stem (ES) cells, constitutively expressing the GFP, were labeled by a lipofection procedure with a MRI contrast agent and implanted into rat brains. Focal cerebral ischemia had been induced 2 weeks before implantation of ES cells into the healthy, contralateral hemisphere. MRI at 78-μm isotropic spatial resolution permitted the observation of the implanted cells with high contrast against the host tissue, and was confirmed by GFP registration. During 3 weeks, cells migrated along the corpus callosum to the ventricular walls, and massively populated the borderzone of the damaged brain tissue on the hemisphere opposite to the implantation sites. Our results indicate that ES cells have high migrational dynamics, targeted to the cerebral lesion area. The imaging approach is ideally suited for the noninvasive observation of cell migration, engraftment, and morphological differentiation at high spatial and temporal resolution. PMID:12444255

A microcontroller-based implantable nerve stimulator used for rats.

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Sha, Hong; Zheng, Zheng; Wang, Yan; Ren, Chaoshi

2005-01-01

A microcontroller-based stimulator that can be flexible programmed after it has been implanted into a rat was studied. Programmability enables implanted stimulators to generate customized, complex protocols for experiments. After implantation, a coded light pulse train that contains information of specific identification will unlock a certain stimulator. If a command that changing the parameters is received, the microcontroller will update its flash memory after it affirms the commands. The whole size of it is only 1.6 cubic centimeters, and it can work for a month. The devices have been successfully used in animal behavior experiments, especially on rats.

Direct implantation versus platelet-rich fibrin-embedded adipose-derived mesenchymal stem cells in treating rat acute myocardial infarction.

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Sun, Cheuk-Kwan; Zhen, Yen-Yi; Leu, Steve; Tsai, Tzu-Hsien; Chang, Li-Teh; Sheu, Jiunn-Jye; Chen, Yung-Lung; Chua, Sarah; Chai, Han-Tan; Lu, Hung-I; Chang, Hsueh-Wen; Lee, Fan-Yen; Yip, Hon-Kan

2014-05-15

This study tested whether adipose-derived mesenchymal stem cells (ADMSC) embedded in platelet-rich fibrin (PRF) scaffold is superior to direct ADMSC implantation in improving left ventricular (LV) performance and reducing LV remodeling in a rat acute myocardial infarction (AMI) model of left anterior descending coronary artery (LAD) ligation. Twenty-eight male adult Sprague Dawley rats equally divided into group 1 [sham control], group 2 (AMI only), group 3 (AMI+direct ADMSC implantation), and group 4 (AMI+PRF-embedded autologous ADMSC) were sacrificed on day 42 after AMI. LV systolic and diastolic dimensions and volumes, and infarct/fibrotic areas were highest in group 2, lowest in group 1 and significantly higher in group 3 than in group 4, whereas LV performance and LV fractional shortening exhibited a reversed pattern (p<0.005). Protein expressions of inflammation (oxidative stress, IL-1β, MMP-9), apoptosis (mitochondrial Bax, cleaved PARP), fibrosis (Smad3, TGF-β), and pressure-overload biomarkers (BNP, MHC-β) displayed a pattern similar to that of LV dimensions, whereas anti-inflammatory (IL-10), anti-apoptotic (Bcl-2), and anti-fibrotic (Smad1/5, BMP-2) indices showed a pattern similar to that of LV performance among the four groups (all p<0.05). Angiogenesis biomarkers at protein (CXCR4, SDF-1α, VEGF), cellular (CD31+, CXCR4+, SDF-1α+), and immunohistochemical (small vessels) levels, and cardiac stem cell markers (C-kit+, Sca-1+) in infarct myocardium were highest in group 4, lowest in group 1, and significantly higher in group 3 than in group 2 (all p<0.005). PRF-embedded ADMSC is superior to direct ADMSC implantation in preserving LV function and attenuating LV remodeling. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Transcatheter aortic valve implantation in failed bioprosthetic surgical valves

DEFF Research Database (Denmark)

Dvir, Danny; Webb, John G; Bleiziffer, Sabine

2014-01-01

for patients with structural valve deterioration; however, a comprehensive evaluation of survival after the procedure has not yet been performed. OBJECTIVE: To determine the survival of patients after transcatheter valve-in-valve implantation inside failed surgical bioprosthetic valves. DESIGN, SETTING......, stroke, and New York Heart Association functional class. RESULTS: Modes of bioprosthesis failure were stenosis (n = 181 [39.4%]), regurgitation (n = 139 [30.3%]), and combined (n = 139 [30.3%]). The stenosis group had a higher percentage of small valves (37% vs 20.9% and 26.6% in the regurgitation...... and combined groups, respectively; P = .005). Within 1 month following valve-in-valve implantation, 35 (7.6%) patients died, 8 (1.7%) had major stroke, and 313 (92.6%) of surviving patients had good functional status (New York Heart Association class I/II). The overall 1-year Kaplan-Meier survival rate was 83...

Vitamin D fails to prevent serum starvation- or staurosporine-induced apoptosis in human and rat osteosarcoma-derived cell lines

International Nuclear Information System (INIS)

Witasp, Erika; Gustafsson, Ann-Catrin; Cotgreave, Ian; Lind, Monica; Fadeel, Bengt

2005-01-01

Previous studies have suggested that 1,25(OH) 2 D 3 , the active form of vitamin D 3 , may increase the survival of bone-forming osteoblasts through an inhibition of apoptosis. On the other hand, vitamin D 3 has also been shown to trigger apoptosis in human cancer cells, including osteosarcoma-derived cell lines. In the present study, we show that 1,25(OH) 2 D 3 induces a time- and dose-dependent loss of cell viability in the rat osteosarcoma cell line, UMR-106, and the human osteosarcoma cell line, TE-85. We were unable, however, to detect nuclear condensation, phosphatidylserine externalization, or other typical signs of apoptosis in this model. Moreover, 1,25(OH) 2 D 3 failed to protect against apoptosis induced by serum starvation or incubation with the protein kinase inhibitor, staurosporine. These in vitro findings are thus at variance with several previous reports in the literature and suggest that induction of or protection against apoptosis of bone-derived cells may not be a primary function of vitamin D 3

Influence of bone marrow-derived mesenchymal stem cells pre-implantation differentiation approach on periodontal regeneration in vivo.

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Cai, Xinjie; Yang, Fang; Yan, Xiangzhen; Yang, Wanxun; Yu, Na; Oortgiesen, Daniel A W; Wang, Yining; Jansen, John A; Walboomers, X Frank

2015-04-01

The implantation of bone marrow-derived mesenchymal stem cells (MSCs) has previously been shown successful to achieve periodontal regeneration. However, the preferred pre-implantation differentiation strategy (e.g. maintenance of stemness, osteogenic or chondrogenic induction) to obtain optimal periodontal regeneration is still unknown. This in vivo study explored which differentiation approach is most suitable for periodontal regeneration. Mesenchymal stem cells were obtained from Fischer rats and seeded onto poly(lactic-co-glycolic acid)/poly(ɛ-caprolactone) electrospun scaffolds, and then pre-cultured under different in vitro conditions: (i) retention of multilineage differentiation potential; (ii) osteogenic differentiation approach; and (iii) chondrogenic differentiation approach. Subsequently, the cell-scaffold constructs were implanted into experimental periodontal defects of Fischer rats, with empty scaffolds as controls. After 6 weeks of implantation, histomorphometrical analyses were applied to evaluate the regenerated periodontal tissues. The chondrogenic differentiation approach showed regeneration of alveolar bone and ligament tissues. The retention of multilineage differentiation potential supported only ligament regeneration, while the osteogenic differentiation approach boosted alveolar bone regeneration. Chondrogenic differentiation of MSCs before implantation is a useful strategy for regeneration of alveolar bone and periodontal ligament, in the currently used rat model. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Surgical Results of Trabeculectomy and Ahmed Valve Implantation Following a Previous Failed Trabeculectomy in Primary Congenital Glaucoma Patients

OpenAIRE

Lee, Naeun; Ma, Kyoung Tak; Bae, Hyoung Won; Hong, Samin; Seong, Gong Je; Hong, Young Jae; Kim, Chan Yun

2015-01-01

Purpose To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. Methods A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. Results The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9...

Perianal implantation of bioengineered human internal anal sphincter constructs intrinsically innervated with human neural progenitor cells.

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Raghavan, Shreya; Miyasaka, Eiichi A; Gilmont, Robert R; Somara, Sita; Teitelbaum, Daniel H; Bitar, Khalil N

2014-04-01

The internal anal sphincter (IAS) is a major contributing factor to pressure within the anal canal and is required for maintenance of rectoanal continence. IAS damage or weakening results in fecal incontinence. We have demonstrated that bioengineered, intrinsically innervated, human IAS tissue replacements possess key aspects of IAS physiology, such as the generation of spontaneous basal tone and contraction/relaxation in response to neurotransmitters. The objective of this study is to demonstrate the feasibility of implantation of bioengineered IAS constructs in the perianal region of athymic rats. Human IAS tissue constructs were bioengineered from isolated human IAS circular smooth muscle cells and human enteric neuronal progenitor cells. After maturation of the bioengineered constructs in culture, they were implanted operatively into the perianal region of athymic rats. Platelet-derived growth factor was delivered to the implanted constructs through a microosmotic pump. Implanted constructs were retrieved from the animals 4 weeks postimplantation. Animals tolerated the implantation well, and there were no early postoperative complications. Normal stooling was observed during the implantation period. At harvest, implanted constructs were adherent to the perirectal rat tissue and appeared healthy and pink. Immunohistochemical analysis revealed neovascularization. Implanted smooth muscle cells maintained contractile phenotype. Bioengineered constructs responded in vitro in a tissue chamber to neuronally evoked relaxation in response to electrical field stimulation and vasoactive intestinal peptide, indicating the preservation of neuronal networks. Our results indicate that bioengineered innervated IAS constructs can be used to augment IAS function in an animal model. This is a regenerative medicine based therapy for fecal incontinence that would directly address the dysfunction of the IAS muscle. Copyright © 2014 Mosby, Inc. All rights reserved.

Bone tissue engineering for spine fusion : An experimental study on ectopic and orthotopic implants in rats

NARCIS (Netherlands)

van Gaalen, SM; Dhert, WJA; van den Muysenberg, A; Oner, FC; van Blitterswijk, C; Verbout, AJ; de Bruijn, J.D.

2004-01-01

Alternatives to the use of autologous bone as a bone graft in spine surgery are needed. The purpose of this study was to examine tissue-engineered bone constructs in comparison with control scaffolds without cells in a posterior spinal implantation model in rats. Syngeneic bone marrow cells were

Warfarin affects acute inflammatory response induced by subcutaneous polyvinyl sponge implantation in rats.

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Mirkov, Ivana; Popov Aleksandrov, Aleksandra; Demenesku, Jelena; Ninkov, Marina; Mileusnic, Dina; Kataranovski, Dragan; Kataranovski, Milena

2017-09-01

Warfarin (WF) is an anticoagulant which also affects physiological processes other than hemostasis. Our previous investigations showed the effect of WF which gained access to the organism via skin on resting peripheral blood granulocytes. Based on these data, the aim of the present study was to examine whether WF could modulate the inflammatory processes as well. To this aim the effect of WF on the inflammatory response induced by subcutaneous sponge implantation in rats was examined. Warfarin-soaked polyvinyl sponges (WF-sponges) were implanted subcutaneously and cell infiltration into sponges, the levels of nitric oxide (NO) and inflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6) production by sponge cells were measured as parameters of inflammation. T cell infiltration and cytokine interferon-γ (IFN-γ), interleukin-17 (IL-17) and interleukin-10 (IL-10) were measured at day 7 post implantation. Warfarin exerted both stimulatory and suppressive effects depending on the parameter examined. Flow cytometry of cells recovered from sponges showed higher numbers of granulocytes (HIS48 + cells) at days 1 and 3 post implantation and CD11b + cells at day 1 compared to control sponges. Cells from WF-sponges had an increased NO production (Griess reaction) at days 1 and 7. In contrast, lower levels of TNF (measured by ELISA) production by cells recovered from WF-soaked sponges were found in the early (day one) phase of reaction with unchanged levels at other time points. While IL-6 production by cells recovered from WF-soaked sponges was decreased at day 1, it was increased at day 7. Higher T cell numbers were noted in WF sponges at day 7 post implantation, and recovered cells produced more IFN-γ and IL-17, while IL-10 production remained unchanged. Warfarin affects some of the parameters of inflammatory reaction induced by subcutaneous polyvinyl sponge implantation. Differential (both stimulatory as well as inhibitory) effects of WF on

Destiny of autologous bone marrow-derived stromal cells implanted in the vocal fold.

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Kanemaru, Shin-ichi; Nakamura, Tatsuo; Yamashita, Masaru; Magrufov, Akhmar; Kita, Tomoko; Tamaki, Hisanobu; Tamura, Yoshihiro; Iguchi, Fuku-ichiro; Kim, Tae Soo; Kishimoto, Masanao; Omori, Koichi; Ito, Juichi

2005-12-01

The aim of this study was to investigate the destiny of implanted autologous bone marrow-derived stromal cells (BSCs) containing mesenchymal stem cells. We previously reported the successful regeneration of an injured vocal fold through implantation of BSCs in a canine model. However, the fate of the implanted BSCs was not examined. In this study, implanted BSCs were traced in order to determine the type of tissues resulting at the injected site of the vocal fold. After harvest of bone marrow from the femurs of green fluorescent transgenic mice, adherent cells were cultured and selectively amplified. By means of a fluorescence-activated cell sorter, it was confirmed that some cells were strongly positive for mesenchymal stem cell markers, including CD29, CD44, CD49e, and Sca-1. These cells were then injected into the injured vocal fold of a nude rat. Immunohistologic examination of the resected vocal folds was performed 8 weeks after treatment. The implanted cells were alive in the host tissues and showed positive expression for keratin and desmin, markers for epithelial tissue and muscle, respectively. The implanted BSCs differentiated into more than one tissue type in vivo. Cell-based tissue engineering using BSCs may improve the quality of the healing process in vocal fold injuries.

Possible sources of neuroprotection following subretinal silicon chip implantation in RCS rats

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Pardue, Machelle T.; Phillips, Michael J.; Yin, Hang; Fernandes, Alcides; Cheng, Yian; Chow, Alan Y.; Ball, Sherry L.

2005-03-01

Current retinal prosthetics are designed to stimulate existing neural circuits in diseased retinas to create a visual signal. However, implantation of retinal prosthetics may create a neurotrophic environment that also leads to improvements in visual function. Possible sources of increased neuroprotective effects on the retina may arise from electrical activity generated by the prosthetic, mechanical injury due to surgical implantation, and/or presence of a chronic foreign body. This study evaluates these three neuroprotective sources by implanting Royal College of Surgeons (RCS) rats, a model of retinitis pigmentosa, with a subretinal implant at an early stage of photoreceptor degeneration. Treatment groups included rats implanted with active and inactive devices, as well as sham-operated. These groups were compared to unoperated controls. Evaluation of retinal function throughout an 18 week post-implantation period demonstrated transient functional improvements in eyes implanted with an inactive device at 6, 12 and 14 weeks post-implantation. However, the number of photoreceptors located directly over or around the implant or sham incision was significantly increased in eyes implanted with an active or inactive device or sham-operated. These results indicate that in the RCS rat localized neuroprotection of photoreceptors from mechanical injury or a chronic foreign body may provide similar results to subretinal electrical stimulation at the current output evaluated here.

Increased expression of heat shock protein 105 in rat uterus of early pregnancy and its significance in embryo implantation

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Hu Zhao-Yuan

2009-03-01

Full Text Available Abstract Background Heat shock proteins (Hsps are a set of highly conserved proteins, Hsp105, has been suggested to play a role in reproduction. Methods Spatio-temporal expression of Hsp105 in rat uterus during peri-implantation period was examined by immunohistochemistry and Western blot, pseudopregnant uterus was used as control. Injection of antisense oligodeoxynucleotides to Hsp105 into pregnant rat uteri was carried out to look at effect of Hsp105 on embryo implantation. Results Expression of Hsp105 was mainly in the luminal epithelium on day 1 of pregnancy, and reached a peak level on day 5, whereas in stroma cells, adjacent to the implanting embryo, the strongest expression of Hsp105 was observed on day 6. The immunostaining profile in the uterus was consistent with that obtained by Western blot in the early pregnancy. In contrast, no obvious peak level of Hsp105 was observed in the uterus of pseudopregnant rat on day 5 or day 6. Furthermore, injection of antisense oligodeoxynucleotides to Hsp105 into the rat uterine horn on day 3 of pregnancy obviously suppressed the protein expression as expected and reduced number of the implanted embryos as compared with the control. Conclusion Temporal and spatial changes in Hsp105 expression in pregnant rat uterus may play a physiological role in regulating embryo implantation.

Modes of failure of Osteonics constrained tripolar implants: a retrospective analysis of forty-three failed implants.

Science.gov (United States)

Guyen, Olivier; Lewallen, David G; Cabanela, Miguel E

2008-07-01

The Osteonics constrained tripolar implant has been one of the most commonly used options to manage recurrent instability after total hip arthroplasty. Mechanical failures were expected and have been reported. The purpose of this retrospective review was to identify the observed modes of failure of this device. Forty-three failed Osteonics constrained tripolar implants were revised at our institution between September 1997 and April 2005. All revisions related to the constrained acetabular component only were considered as failures. All of the devices had been inserted for recurrent or intraoperative instability during revision procedures. Seven different methods of implantation were used. Operative reports and radiographs were reviewed to identify the modes of failure. The average time to failure of the forty-three implants was 28.4 months. A total of five modes of failure were observed: failure at the bone-implant interface (type I), which occurred in eleven hips; failure at the mechanisms holding the constrained liner to the metal shell (type II), in six hips; failure of the retaining mechanism of the bipolar component (type III), in ten hips; dislocation of the prosthetic head at the inner bearing of the bipolar component (type IV), in three hips; and infection (type V), in twelve hips. The mode of failure remained unknown in one hip that had been revised at another institution. The Osteonics constrained tripolar total hip arthroplasty implant is a complex device involving many parts. We showed that failure of this device can occur at most of its interfaces. It would therefore appear logical to limit its application to salvage situations.

Effect of TheraCyte-encapsulated parathyroid cells on lumbar fusion in a rat model.

Science.gov (United States)

Chen, Sung-Hsiung; Huang, Shun-Chen; Lui, Chun-Chung; Lin, Tzu-Ping; Chou, Fong-Fu; Ko, Jih-Yang

2012-09-01

Implantation of TheraCyte 4 × 10(6) live parathyroid cells can increase the bone marrow density of the spine of ovariectomized rats. There has been no published study examining the effect of such implantation on spinal fusion outcomes. The purpose of this study was to examine the effect of TheraCyte-encapsulated parathyroid cells on posterolateral lumbar fusions in a rat model. Forty Sprague-Dawley rats underwent single-level, intertransverse process spinal fusions using iliac crest autograft. The rats were randomly assigned to two groups: Group 1 rats received sham operations on their necks (control; N = 20); Group 2 rats were implanted with TheraCyte-encapsulated 4 × 10(6) live parathyroid cells into the subcutis of their necks (TheraCyte; N = 20). Six weeks after surgery the rats were killed. Fusion was assessed by inspection, manual palpation, radiography, and histology. Blood was drawn to measure the serum levels of calcium, phosphorus, and intact parathyroid hormone (iPTH). Based on manual palpation, the control group had a fusion rate of 33 % (6/18) and the TheraCyte group had a fusion rate of 72 % (13/18) (P = 0.044). Histology confirmed the manual palpation results. Serum iPTH levels were significantly higher in the TheraCyte group compared with the control group (P TheraCyte-encapsulated 4 × 10(6) live parathyroid cells than in control rats without significant change in serum calcium or phosphorus concentrations. As with any animal study, the results may not extrapolate to a higher species. Further studies are needed to determine if these effects are clinically significant.

Suspension Matrices for Improved Schwann-Cell Survival after Implantation into the Injured Rat Spinal Cord

Science.gov (United States)

Patel, Vivek; Joseph, Gravil; Patel, Amit; Patel, Samik; Bustin, Devin; Mawson, David; Tuesta, Luis M.; Puentes, Rocio; Ghosh, Mousumi

2010-01-01

Abstract Trauma to the spinal cord produces endogenously irreversible tissue and functional loss, requiring the application of therapeutic approaches to achieve meaningful restoration. Cellular strategies, in particular Schwann-cell implantation, have shown promise in overcoming many of the obstacles facing successful repair of the injured spinal cord. Here, we show that the implantation of Schwann cells as cell suspensions with in-situ gelling laminin:collagen matrices after spinal-cord contusion significantly enhances long-term cell survival but not proliferation, as well as improves graft vascularization and the degree of axonal in-growth over the standard implantation vehicle, minimal media. The use of a matrix to suspend cells prior to implantation should be an important consideration for achieving improved survival and effectiveness of cellular therapies for future clinical application. PMID:20144012

Improved Bone Micro Architecture Healing Time after Implant Surgery in an Ovariectomized Rat.

Science.gov (United States)

Takahashi, Takahiro; Watanabe, Takehiro; Nakada, Hiroshi; Sato, Hiroki; Tanimoto, Yasuhiro; Sakae, Toshiro; Kimoto, Suguru; Mijares, Dindo; Zhang, Yu; Kawai, Yasuhiko

2016-01-01

The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improves peri-implant bone formation and bone micro architecture (BMA). SBM was used as an intervention experimental diet and AIN-93M was used as a control. The SBM was prepared by mixing dicalcium phosphate dihydrate (CaHPO 4 ·2H 2 O) and magnesium and zinc chlorides (MgCl 2 and ZnCl 2 , respectively), and hydrolyzed in double-distilled water containing dissolved potassium carbonate and sodium fluoride. All rats were randomly allocated into one of two groups: a control group was fed without SBM (n = 18) or an experimental group was fed with SBM (n = 18), at seven weeks old. At 9 weeks old, all rats underwent implant surgery on their femurs under general anesthesia. The implant was inserted into the insertion socket prepared at rats' femur to a depth of 2.5 mm by using a drill at 500 rpm. Nine rats in each group were randomly selected and euthanized at 2 weeks after implantation. The remaining nine rats in each group continued their diets, and were euthanized in the same manner at 4 weeks after implantation. The femur, including the implant, was removed from the body and implant was pulled out by an Instron universal testing machine. After the implant removal, BMA was evaluated by bone surface ratio (BS/BV), bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN), trabecular star volume (Vtr), and micro-CT images. BS/BV, BV/TV, TbTh and Vtr were significantly greater in the rats were fed with SBM than those were fed without SBM at 2 and 4 weeks after implantation (P implant formation and BMA, prominent with trabecular bone structure. The effect of SBM to improve secondary stability of the implant, and shortening the treatment period should be investigated in the future study.

Determination of metallic traces in kidneys, livers, lungs and spleens of rats with metallic implants after a long implantation time.

Science.gov (United States)

Rubio, Juan Carlos; Garcia-Alonso, Maria Cristina; Alonso, Concepcion; Alobera, Miguel Angel; Clemente, Celia; Munuera, Luis; Escudero, Maria Lorenza

2008-01-01

Metallic transfer from implants does not stop at surrounding tissues, and metallic elements may be transferred by proteins to become lodged in organs far from the implant. This work presents an in vivo study of metallic implant corrosion to measure metallic element accumulation in organs located far from the implant, such as kidneys, livers, lungs and spleens. The studied metallic implant materials were CoCr alloy, Ti, and the experimental alloy MA956 coated with alpha-alumina. The implants were inserted in the hind legs of Wistar rats. Analysis for Co, Cr, Ti and Al metallic traces was performed after a long exposure time of 12 months by Inductively Coupled Plasma (ICP) with Mass Spectrometry (MS). According to the results, the highest Cr and Ti concentrations were detected in spleens. Co is mainly found in kidneys, since this element is eliminated via urine. Cr and Ti traces increased significantly in rat organs after the long implantation time. The organs of rats implanted with the alpha-alumina coated experimental MA956 did not present any variation in Al content after 12 months, which means there was no degradation of the alumina layer surface.

Implanting Glioblastoma Spheroids into Rat Brains and Monitoring Tumor Growth by MRI Volumetry.

Science.gov (United States)

Löhr, Mario; Linsenmann, Thomas; Jawork, Anna; Kessler, Almuth F; Timmermann, Nils; Homola, György A; Ernestus, Ralf-Ingo; Hagemann, Carsten

2017-01-01

The outcome of patients suffering from glioblastoma multiforme (GBM) remains poor with a median survival of less than 15 months. To establish innovative therapeutical approaches or to analyze the effect of protein overexpression or protein knockdown by RNA interference in vivo, animal models are mandatory. Here, we describe the implantation of C6 glioma spheroids into the rats' brain and how to follow tumor growth by MRI scans. We show that C6 cells grown in Sprague-Dawley rats share several morphologic features of human glioblastoma like pleomorphic cells, areas of necrosis, vascular proliferation, and tumor cell invasion into the surrounding brain tissue. In addition, we describe a method for tumor volumetry utilizing the CISS 3D- or contrast-enhanced T1-weighted 3D sequence and freely available post-processing software.

Insulin-like growth factor binding protein-3 affects osteogenic efficacy on dental implants in rat mandible

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Bhattarai, Govinda; Lee, Young-Hee [Department of Oral Biochemistry, Institute of Oral Bioscience, School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Lee, Min-Ho [Department of Dental Materials, Institute of Oral Bioscience, School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Park, Il-Song [Division of Advanced Materials Engineering, Research Center for Advanced Materials, Development and Institute of Biodegradable Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Yi, Ho-Keun, E-mail: yihokn@chonbuk.ac.kr [Department of Oral Biochemistry, Institute of Oral Bioscience, School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

2015-10-01

Insulin like growth factor binding protein-3 (IGFBP-3) in bone cells and its utilization in dental implants have not been well studied. The aim of this study was to determine the osteogenic efficacy of chitosan gold nanoparticles (Ch-GNPs) conjugated with IGFBP-3 coated titanium (Ti) implants. Ch-GNPs were conjugated with IGFBP-3 plasmid DNA through a coacervation process. Conjugation was cast over Ti surfaces, and cells were seeded on coated surfaces. For in vitro analysis the expression of different proteins was analyzed by immunoblotting. For in vivo analysis, Ch-GNP/IGFBP-3 coated implants were installed in rat mandibles. Four weeks post-implantation, mandibles were examined by microcomputed tomography (μCT), immunohistochemistry, hematoxylin & eosin and tartrate resistance acid phosphatase staining. In vitro overexpressed Ch-GNP/IGFBP-3 coated Ti surfaces was associated with activation of extracellular signal related kinase (ERK), inhibition of the stress activated protein c-Jun N-terminal kinase (JNK) and enhanced bone morphogenetic protein (BMP)-2 and 7 compared to control. Further, in vivo, Ch-GNP/IGFBP-3 coated implants were associated with inhibition of implant induced osteoclastogenesis molecules, receptor activator of nuclear factor kappa-B ligand (RANKL) and enhanced expression of osteogenic molecules including BMP2/7 and osteopontin (OPN). The μCT analysis demonstrated that IGFBP-3 increased the volume of newly formed bone surrounding the implants compared to control (n = 5; p < 0.05). These results support the view that IGFBP-3 overexpression diminishes osteoclastogenesis and enhances osteogenesis of Ti implants, and can serve as a potent molecule for the development of good implantation. - Highlights: • Chitosan gold nanoparticles were conjugated with IGFBP-3 and coated onto surface of the titanium implants for gene delivery to bone. • Implants were inserted in rat mandible for 4 weeks. • Parameters studied: histopathology and radiology. �

Insulin-like growth factor binding protein-3 affects osteogenic efficacy on dental implants in rat mandible

International Nuclear Information System (INIS)

Bhattarai, Govinda; Lee, Young-Hee; Lee, Min-Ho; Park, Il-Song; Yi, Ho-Keun

2015-01-01

Insulin like growth factor binding protein-3 (IGFBP-3) in bone cells and its utilization in dental implants have not been well studied. The aim of this study was to determine the osteogenic efficacy of chitosan gold nanoparticles (Ch-GNPs) conjugated with IGFBP-3 coated titanium (Ti) implants. Ch-GNPs were conjugated with IGFBP-3 plasmid DNA through a coacervation process. Conjugation was cast over Ti surfaces, and cells were seeded on coated surfaces. For in vitro analysis the expression of different proteins was analyzed by immunoblotting. For in vivo analysis, Ch-GNP/IGFBP-3 coated implants were installed in rat mandibles. Four weeks post-implantation, mandibles were examined by microcomputed tomography (μCT), immunohistochemistry, hematoxylin & eosin and tartrate resistance acid phosphatase staining. In vitro overexpressed Ch-GNP/IGFBP-3 coated Ti surfaces was associated with activation of extracellular signal related kinase (ERK), inhibition of the stress activated protein c-Jun N-terminal kinase (JNK) and enhanced bone morphogenetic protein (BMP)-2 and 7 compared to control. Further, in vivo, Ch-GNP/IGFBP-3 coated implants were associated with inhibition of implant induced osteoclastogenesis molecules, receptor activator of nuclear factor kappa-B ligand (RANKL) and enhanced expression of osteogenic molecules including BMP2/7 and osteopontin (OPN). The μCT analysis demonstrated that IGFBP-3 increased the volume of newly formed bone surrounding the implants compared to control (n = 5; p < 0.05). These results support the view that IGFBP-3 overexpression diminishes osteoclastogenesis and enhances osteogenesis of Ti implants, and can serve as a potent molecule for the development of good implantation. - Highlights: • Chitosan gold nanoparticles were conjugated with IGFBP-3 and coated onto surface of the titanium implants for gene delivery to bone. • Implants were inserted in rat mandible for 4 weeks. • Parameters studied: histopathology and radiology. �

Immediate Reconstruction of Failed Implants in the Esthetic Zone Using a Flapless Technique and Autogenous Composite Tuberosity Graft

NARCIS (Netherlands)

Raghoebar, Gerry M; Meijer, Henny J A; van Minnen, Baucke; Vissink, Arjan

We describe a technique for immediate reconstruction of bone after removal of failed dental implants in the esthetic region to optimize the esthetic outcome of retreatment. We conducted a study of 16 consecutive patients in whom the bony defect resulting from implant removal was immediately

EGF increases expression and activity of PAs in preimplantation rat embryos and their implantation rate

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Har-Vardi Iris

2007-01-01

Full Text Available Abstract Background Embryo implantation plays a major role in embryogenesis and the outcome of pregnancy. Plasminogen activators (PAs have been implicated in mammalian fertilization, early stages of development and embryo implantation. As in-vitro developing embryos resulted in lower implantation rate than those developed in-vivo we assume that a reduced PAs activity may be involved. In the present work we studied the effect of EGF on PAs activity, quantity and embryo implantation. Methods Zygotes were flushed from rat oviducts on day one of pregnancy and grown in-vitro in R1ECM supplemented with EGF (10 ng/ml and were grown up to the blastocyst stage. The control groups were grown in the same medium without EGF. The distribution and quantity of the PAs were examined using fluorescence immunohistochemistry followed by measurement of PAs activity using the chromogenic assay. Implantation rate was studied using the embryo donation model. Results PAs distribution in the embryos was the same in EGF treated and untreated embryos. Both PAs were localized in the blastocysts' trophectoderm, supporting the assumption that PAs play a role in the implantation process in rats. EGF increased the quantity of uPA at all stages studied but the 8-cell stage as compared with controls. The tissue type PA (tPA content was unaffected except the 8-cell stage, which was increased. The activity of uPA increased gradually towards the blastocyst stage and more so due to the presence of EGF. The activity of tPA did not vary with the advancing developmental stages although it was also increased by EGF. The presence of EGF during the preimplantation development doubled the rate of implantation of the treated group as compared with controls.

Surgical results of trabeculectomy and Ahmed valve implantation following a previous failed trabeculectomy in primary congenital glaucoma patients.

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Lee, Naeun; Ma, Kyoung Tak; Bae, Hyoung Won; Hong, Samin; Seong, Gong Je; Hong, Young Jae; Kim, Chan Yun

2015-04-01

To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38). There was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis.

Effects of mechanical repetitive load on bone quality around implants in rat maxillae.

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Yusuke Uto

Full Text Available Greater understanding and acceptance of the new concept "bone quality", which was proposed by the National Institutes of Health and is based on bone cells and collagen fibers, are required. The novel protein Semaphorin3A (Sema3A is associated with osteoprotection by regulating bone cells. The aims of this study were to investigate the effects of mechanical loads on Sema3A production and bone quality based on bone cells and collagen fibers around implants in rat maxillae. Grade IV-titanium threaded implants were placed at 4 weeks post-extraction in maxillary first molars. Implants received mechanical loads (10 N, 3 Hz for 1800 cycles, 2 days/week for 5 weeks from 3 weeks post-implant placement to minimize the effects of wound healing processes by implant placement. Bone structures, bone mineral density (BMD, Sema3A production and bone quality based on bone cells and collagen fibers were analyzed using microcomputed tomography, histomorphometry, immunohistomorphometry, polarized light microscopy and birefringence measurement system inside of the first and second thread (designated as thread A and B, respectively, as mechanical stresses are concentrated and differently distributed on the first two threads from the implant neck. Mechanical load significantly increased BMD, but not bone volume around implants. Inside thread B, but not thread A, mechanical load significantly accelerated Sema3A production with increased number of osteoblasts and osteocytes, and enhanced production of both type I and III collagen. Moreover, mechanical load also significantly induced preferential alignment of collagen fibers in the lower flank of thread B. These data demonstrate that mechanical load has different effects on Sema3A production and bone quality based on bone cells and collagen fibers between the inside threads of A and B. Mechanical load-induced Sema3A production may be differentially regulated by the type of bone structure or distinct stress distribution

Transition from failing dentition to complete-arch implant rehabilitation with a staged approach: a 3-year clinical report.

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Papaspyridakos, Panos; Chronopoulos, Vasilios

2014-09-01

The transition of patients from failing dentition to complete-arch implant rehabilitation often means that the patient is rendered edentulous and has to wear a removable complete denture for a time. Many patients find this objectionable. A staged treatment approach provides a fixed interim prosthesis for use throughout the rehabilitation process, allowing patient comfort and prosthodontic control. This clinical report describes a staged approach protocol with a new type of interim prosthesis. The prosthesis is supported by hopeless teeth and the soft tissues of the maxillary tuberosities and mandibular retromolar pads for the complete-arch implant rehabilitation of a patient with failing dentition. This protocol allows for a fixed interim prosthesis with combined tooth and mucosa or implant support during the entire rehabilitation process, thus avoiding the use of complete dentures. The implants and prostheses were functioning successfully after 3 years of clinical service. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

[Effect of low dose aspirin on osseointegration around titanium implants in osteoporotic rats].

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Yang, Q; Li, F L

2018-02-09

Objective: To investigate the effect of aspirin on osseointegration around titanium implants in ostoeporotic rats and to provide evidence for future researches and clinical application. Methods: A total of 60 female SD rats, aged 3-4 months, were divided into ovariectomy group (Ovx group, n= 48) and sham-ovariectomy group (Sham group, n= 12). The rats in Ovx group received ovariectomy and those in Sham group underwent sham-ovariectomy. Twelve weeks later, six rats in each group were randomly selected to confirm the osteoporosis models. The Ovx group was divided into 4 subgroups with 12 rats in each group, namely the osteoporosis group (OP group), and Aspirin groups (A1, A2, A3 group). Pure screw titanium implants were placed in the right tibia near metaphysis of all rats. Three days after implant surgery, aspirin groups were intragastrically administered aspirin at a dose of 2.06, 4.11, 8.21 mg·kg(-1)·d(-1) (A1, A2, A3), and OP group and Sham group were fed the same amount of normal saline. Four and 12 weeks following implantations surgery, half of the rats in each group were randomly chosen and sacrificed. Implant bone contact rate (IBCR), combined bone lamella width (CBLW) and trabercular width (TW) were observed and calculated using histomorphometric measurement. Results: Four weeks after implantations surgery, the TW and CBLW of rats in A1 group [(39.60±2.77) and (27.56±4.14) μm] and the IBCR, TW and CBLW of rats in A2 group and A3 group [A2: (47.21±4.19)%, (48.74±3.20) and (35.91±3.79) μm; A3: (47.35±6.07)%, (50.27±5.25) and (40.66±2.11) μm] were much higher than those in OP group [(33.89±7.17)%, (32.20±6.10) and (19.77±6.80) μm]( P 0.05). Twelve weeks after implantations surgery, the IBCR and CBLW of rats in A1 group [ (85.86±3.64) %, (53.12±8.68) μm], and the IBCR, TW and CBLW of rats in A2 group and A3 group [A2: (85.64±3.97)%, (69.42±6.78) and (54.19±3.12) μm; A3: (86.22±3.48)%, (75.43±3.50) and (55.79±5.60) μm] were much higher

Does gestrinone antagonize the effects of estrogen on endometrial implants upon the peritoneum of rats?

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Vera Lúcia Rodrigues Lobo

2008-01-01

Full Text Available OBJECTIVE: To evaluate the effects of estrogen treatment in combination with gestrinone on an experimental rat model of endometriosis. METHODS: Uterine transplants were attached to the peritoneum of female Wistar rats via a surgical autotransplantation technique. The implanted area was measured during the proestrus phase and after hormonal treatment. We performed morphometric analysis and examined the macroscopic and morphometric alterations of endometrial implants after hormonal treatment in ovariectomized rats. RESULTS: The high dose of estrogen caused macroscopic increases in the endometrial implant group compared with other groups, which were similar to increases in the proestrus phase. The low dose showed morphometric development of implants, such as an increase in number of endometrial glands, leukocyte infiltration and mitosis. Gestrinone antagonized both doses of estrogen. CONCLUSION: Our findings suggest that gestrinone antagonizes estrogen's effects on rat peritoneal endometrial implants.

Time Course of Peri-Implant Bone Regeneration around Loaded and Unloaded Implants in a Rat Model

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Jariwala, Shailly H.; Wee, Hwabok; Roush, Evan P.; Whitcomb, Tiffany L.; Murter, Christopher; Kozlansky, Gery; Lakhtakia, Akhlesh; Kunselman, Allen R.; Donahue, Henry J.; Armstrong, April D.; Lewis, Gregory S.

2018-01-01

The time-course of cancellous bone regeneration surrounding mechanically loaded implants affects implant fixation, and is relevant to determining optimal rehabilitation protocols following orthopaedic surgeries. We investigated the influence of controlled mechanical loading of titanium-coated polyether-ether ketone (PEEK) implants on osseointegration using time-lapsed, non-invasive, in vivo micro-computed tomography (micro-CT) scans. Implants were inserted into proximal tibial metaphyses of both limbs of eight female Sprague-Dawley rats. External cyclic loading (60 μm or 100 μm displacement, 1 Hz, 60 seconds) was applied every other day for 14 days to one implant in each rat, while implants in contralateral limbs served as the unloaded controls. Hind limbs were imaged with high-resolution micro-CT (12.5 μm voxel size) at 2, 5, 9, and 12 days post-surgery. Trabecular changes over time were detected by 3D image registration allowing for measurements of bone-formation rate (BFR) and bone-resorption rate (BRR). At day 9, mean %BV/TV for loaded and unloaded limbs were 35.5 ± 10.0 % and 37.2 ± 10.0 %, respectively, and demonstrated significant increases in bone volume compared to day 2. BRR increased significantly after day 9. No significant differences between bone volumes, BFR, and BRR were detected due to implant loading. Although not reaching significance (p = 0.16), an average 119 % increase in pull-out strength was measured in the loaded implants. PMID:27381807

Treatment of osteoporosis with TheraCyte-encapsulated parathyroid cells: a study in a rat model.

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Chou, F-F; Huang, S-C; Chen, S-S; Wang, P-W; Huang, P-H; Lu, K-Y

2006-01-01

The purpose of this study was to evaluate parathyroid function at monthly intervals following the implantation of TheraCyte-encapsulated live human parathyroid cells into ovariectomized rats and to determine the effect on bone mineral density (BMD) 4 months after ovariectomy ( 3 months after implantation). Parathyroid tissues were obtained from patients undergoing surgery for secondary hyperparathyroidism. In total, 21 Sprague-Dawley rats divided randomly into three groups were subjected to one of three treatments: (1) implanted with TheraCyte A-encapsulated 4x10(6) live parathyroid cells; (2) implanted with TheraCyte B-encapsulated 4x10(5) live parathyroid cells; (3) a sham operation; the control group. Rats were ovariectomized 1 month prior to the implantation of the TheraCyte. Blood was drawn at the time of implantation and at monthly intervals thereafter for 3 months to check the levels of calcium, phosphorus and intact parathyroid hormone (iPTH). The BMD of the lumbar spine (L1-L5) and of the left femoral bone was measured with dual-energy-X-ray absorptiometry (DEXA) 1 month after ovariectomy and 3 months after implantation of the TheraCyte (4 months after ovariectomy). We found that the viability ratio of cryopreserved tissues was between 55 and 79% after thawing. In the control group, the BMD of the lumbar spine (L1-L5) had not decreased significantly (p=0.237) nor had the BMD of the left femoral bone increased significantly (p=0.063) 3 months after implantation. In the TheraCyte A group, the BMD of both the lumbar spine (p=0.018) and left femoral bone (p=0.018) had increased significantly 3 months after implantation. In the TheraCyte B group, the BMD of both the lumbar spine (p=0.017) and the left femoral bone (p=0.025) had also increased significantly 3 months after implantation. Serum iPTH levels were higher in the TheraCyte A group than in the TheraCyte B group (p=0.006), and higher in the TheraCyte B group than in the control group (p=0.040). Serum

Evaluation of porous vitreous carbon or silicon implants by radiology in rat's skull

International Nuclear Information System (INIS)

Vaccari-Mazzetti, Marcelo Paulo; Kobata, Celio Toshiro; Fabiani, Paulo; Martins, Dulce Maria Fonseca Soares; Gomes, Paulo de Oliveira; Martins, Jose Luiz

2008-01-01

Purpose: Evaluate by CT the use of porous vitreous carbon (PVC) and silicon (S) implants as the replacement bone in the craniofacial skeleton of rats. Methods: 40 rats divided in: Group A (n=20) PVC submitted to the implant of a fragment in skull. After the euthanasia, the animals were divided into two subgroups: A I: 10 animals, studied in the 7th postoperative day (P.O) and AII: 10 animals, studied in the 28th P.O. In group B, S, 20 rats were submitted to S implant in the skull. All other steps were identical to group A, with designation of subgroups BI and BII. CT with beams in axial cuts of 1 mm thickness to obtain 3-D information It was used Hounsfield scale for evaluate the radio density of the implant. They were used non parametric tests to analyze the results. Results: The 7th PO boss remained in the two groups, but for 28th PO, observed reduction in the volume of the implant in Group A, not observed in group B. CT studies noticed different radio densities around all of S prostheses (pseudo capsule), that do not appeared in CPV implants. The S has remained unchanged in the CT, but the CPV has had a modification in its radio density (p≤0,05), in all implants. Conclusion: In CT evaluation the implants of CPV have greater deformation that the S, which makes them not suitable for replacement of membranous bone in the rat skull. (author)

Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats.

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Matveyenko, Aleksey V; Georgia, Senta; Bhushan, Anil; Butler, Peter C

2010-11-01

Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in development of viable glucose-responsive pancreatic endocrine tissue. Athymic nude rats were implanted with PE derived from hESC either via implantation into the epididymal fat pads or by subcutaneous implantation into TheraCyte encapsulation devices for 20 wk. Blood glucose, weight, and human insulin/C-peptide secretion were monitored by weekly blood draws. Graft β-cell function was assessed by a glucose tolerance test, and graft morphology was assessed by immunohistochemistry and immunofluorescence. At 20 wk postimplantation, epididymal fat-implanted PE progressed to develop islet-like structures in 50% of implants, with a mean β-cell fractional area of 0.8 ± 0.3%. Human C-peptide and insulin were detectable, but at very low levels (C-peptide = 50 ± 26 pmol/l and insulin = 15 ± 7 pmol/l); however, there was no increase in human C-peptide/insulin levels after glucose challenge. There was no development of viable pancreatic tissue or meaningful secretory function when human PE was implanted in the TheraCyte encapsulation devices. These data confirm that islet-like structures develop from hESC differentiated to PE by the protocol developed by NovoCell. However, the extent of endocrine cell formation and secretory function is not yet sufficient to be clinically relevant.

In vivo bioluminescence imaging for prolonged survival of transplanted human neural stem cells using 3D biocompatible scaffold in corticectomized rat model.

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Do Won Hwang

Full Text Available Stem cell-based treatment of traumatic brain injury has been limited in its capacity to bring about complete functional recovery, because of the poor survival rate of the implanted stem cells. It is known that biocompatible biomaterials play a critical role in enhancing survival and proliferation of transplanted stem cells via provision of mechanical support. In this study, we noninvasively monitored in vivo behavior of implanted neural stem cells embedded within poly-l-lactic acid (PLLA scaffold, and showed that they survived over prolonged periods in corticectomized rat model. Corticectomized rat models were established by motor-cortex ablation of the rat. F3 cells expressing enhanced firefly luciferase (F3-effLuc were established through retroviral infection. The F3-effLuc within PLLA was monitored using IVIS-100 imaging system 7 days after corticectomized surgery. F3-effLuc within PLLA robustly adhered, and gradually increased luciferase signals of F3-effLuc within PLLA were detected in a day dependent manner. The implantation of F3-effLuc cells/PLLA complex into corticectomized rats showed longer-lasting luciferase activity than F3-effLuc cells alone. The bioluminescence signals from the PLLA-encapsulated cells were maintained for 14 days, compared with 8 days for the non-encapsulated cells. Immunostaining results revealed expression of the early neuronal marker, Tuj-1, in PLLA-F3-effLuc cells in the motor-cortex-ablated area. We observed noninvasively that the mechanical support by PLLA scaffold increased the survival of implanted neural stem cells in the corticectomized rat. The image-guided approach easily proved that scaffolds could provide supportive effect to implanted cells, increasing their viability in terms of enhancing therapeutic efficacy of stem-cell therapy.

Effects of pore size, implantation time and nano-surface properties on rat skin ingrowth into percutaneous porous titanium implants

OpenAIRE

Farrell, Brad J.; Prilutsky, Boris I.; Ritter, Jana M.; Kelley, Sean; Popat, Ketul; Pitkin, Mark

2013-01-01

The main problem of percutaneous osseointegrated implants is poor skin-implant integration, which may cause infection. This study investigated the effects of pore size (Small, 40–100 microns and Large, 100–160 microns), nanotubular surface treatment (Nano), and duration of implantation (3 and 6 weeks) on skin ingrowth into porous titanium. Each implant type was percutaneously inserted in the back of 35 rats randomly assigned to 7 groups. Implant extrusion rate was measured w...

Preparation and biocompatibility study of in situ forming polymer implants in rat brains.

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Nasongkla, Norased; Boongird, Atthaporn; Hongeng, Suradej; Manaspon, Chawan; Larbcharoensub, Noppadol

2012-02-01

We describe the development of polymer implants that were designed to solidify once injected into rat brains. These implants comprised of glycofurol and copolymers of D: ,L: -lactide (LA), ε-caprolactone and poly(ethylene glycol) (PLECs). Scanning electron microscopy (SEM) and gel permeation chromatography (GPC) showed that the extent of implant degradation was increased with LA: content in copolymers. SEM analysis revealed the formation of porosity on implant surface as the degradation proceeds. PLEC with 19.3% mole of LA: was chosen to inject in rat brains at the volume of 10, 25 and 40 μl. Body weights, hematological and histopathological data of rats treated with implants were evaluated on day 3, 6, 14, 30 and 45 after the injection. Polymer solution at the injection volume of 10 μl were tolerated relatively well compared to those of 25 and 40 μl as confirmed by higher body weight and healing action (fibrosis tissue) 30 days after treatment. The results from this study suggest a possible application as drug delivery systems that can bypass the blood brain barrier.

Micro-morphologic changes around biophysically-stimulated titanium implants in ovariectomized rats

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Chang Ting-Ling

2007-07-01

Full Text Available Abstract Background Osteoporosis may present a risk factor in achievement of osseointegration because of its impact on bone remodeling properties of skeletal phsiology. The purpose of this study was to evaluate micro-morphological changes in bone around titanium implants exposed to mechanical and electrical-energy in osteoporotic rats. Methods Fifteen 12-week old sprague-dowley rats were ovariectomized to develop osteoporosis. After 8 weeks of healing period, two titanium implants were bilaterally placed in the proximal metaphyses of tibia. The animals were randomly divided into a control group and biophysically-stimulated two test groups with five animals in each group. In the first test group, a pulsed electromagnetic field (PEMF stimulation was administrated at a 0.2 mT 4 h/day, whereas the second group received low-magnitude high-frequency mechanical vibration (MECHVIB at 50 Hz 14 min/day. Following completion of two week treatment period, all animals were sacrificed. Bone sites including implants were sectioned, removed en bloc and analyzed using a microCT unit. Relative bone volume and bone micro-structural parameters were evaluated for 144 μm wide peri-implant volume of interest (VOI. Results Mean relative bone volume in the peri-implant VOI around implants PEMF and MECHVIB was significantly higher than of those in control (P P > .05 while the difference in trabecular-number among test and control groups was significant in all VOIs (P Conclusion Biophysical stimulation remarkably enhances bone volume around titanium implants placed in osteoporotic rats. Low-magnitude high-frequency MECHVIB is more effective than PEMF on bone healing in terms of relative bone volume.

Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats

OpenAIRE

Matveyenko, Aleksey V.; Georgia, Senta; Bhushan, Anil; Butler, Peter C.

2010-01-01

Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in ...

Changes in pituitary growth hormone cells prepared from rats flown on Spacelab 3

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Grindeland, R.; Hymer, W. C.; Farrington, M.; Fast, T.; Hayes, C.; Motter, K.; Patil, L.; Vasques, M.

1987-01-01

The effect of exposure to microgravity on pituitary gland was investigated by examining cells isolated from anterior pituitaries of rats flown on the 7-day Spacelab 3 mission and, subsequently, cultured for 6 days. Compared with ground controls, flight cells contained more intracellular growth hormone (GH); however, the flight cells released less GH over the 6-day culture period and after implantation into hypophysectomized rats than did the control cells. Compared with control rats, glands from large rats (400 g) contained more somatotrophs (44 percent compared with 37 percent in control rats); small rats (200 g) showed no difference. No major differences were found in the somatotroph ultrastructure (by TEM) or in the pattern of the immunoactive GH variants. However, high-performance liquid chromatography fractionation of culture media indicated that flight cells released much less of a biologically active high-molecular weight GH variant, suggesting that space flight may lead to secretory dysfunction.

Acute In Vivo Response to an Alternative Implant for Urogynecology

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Sabiniano Roman Regueros

2014-01-01

Full Text Available Purpose. To investigate in vivo the acute host response to an alternative implant designed for the treatment of stress urinary incontinence (SUI and pelvic organ prolapse (POP. Methods. A biodegradable scaffold was produced from poly-L-lactic acid (PLA using the electrospinning technique. Human and rat adipose-derived stem cells (ADSCs were isolated and characterized by fluorescence-activated cell sorting and differentiation assays. PLA scaffolds were seeded and cultured for 2 weeks with human or rat ADSCs. Scaffolds with and without human or rat ADSCs were implanted subcutaneously on the abdominal wall of rats. After 3 and 7 days, 6 animals from each group were sacrificed. Sections from each sample were analyzed by Haematoxylin and Eosin staining, Sirius red staining, and immunohistochemistry for CD68, PECAM-1, and collagen I and III. Results. Animals responded to the scaffolds with an acute macrophage response. After 7 days of implantation, there was extensive host cell penetration, new blood vessel formation, and new collagen deposition throughout the full thickness of the samples without obvious differences between cell-containing and cell-free scaffolds. Conclusions. The acute in vivo response to an alternative implant (both with and without cells for the treatment of SUI and POP showed good acute integration into the host tissues.

Survival and Functionality of hESC-Derived Retinal Pigment Epithelium Cells Cultured as a Monolayer on Polymer Substrates Transplanted in RCS Rats.

Science.gov (United States)

Thomas, Biju B; Zhu, Danhong; Zhang, Li; Thomas, Padmaja B; Hu, Yuntao; Nazari, Hossein; Stefanini, Francisco; Falabella, Paulo; Clegg, Dennis O; Hinton, David R; Humayun, Mark S

2016-05-01

To determine the safety, survival, and functionality of human embryonic stem cell-derived RPE (hESC-RPE) cells seeded on a polymeric substrate (rCPCB-RPE1 implant) and implanted into the subretinal (SR) space of Royal College of Surgeons (RCS) rats. Monolayers of hESC-RPE cells cultured on parylene membrane were transplanted into the SR space of 4-week-old RCS rats. Group 1 (n = 46) received vitronectin-coated parylene membrane without cells (rMSPM+VN), group 2 (n = 59) received rCPCB-RPE1 implants, and group 3 (n = 13) served as the control group. Animals that are selected based on optical coherence tomography screening were subjected to visual function assays using optokinetic (OKN) testing and superior colliculus (SC) electrophysiology. At approximately 25 weeks of age (21 weeks after surgery), the eyes were examined histologically for cell survival, phagocytosis, and local toxicity. Eighty-seven percent of the rCPCB-RPE1-implanted animals showed hESC-RPE survivability. Significant numbers of outer nuclear layer cells were rescued in both group 1 (rMSPM+VN) and group 2 (rCPCB-RPE1) animals. A significantly higher ratio of rod photoreceptor cells to cone photoreceptor cells was found in the rCPCB-RPE1-implanted group. Animals with rCPCB-RPE1 implant showed hESC-RPE cells containing rhodopsin-positive particles in immunohistochemistry, suggesting phagocytic function. Superior colliculus mapping data demonstrated that a significantly higher number of SC sites responded to light stimulus at a lower luminance threshold level in the rCPCB-RPE1-implanted group. Optokinetic data suggested both implantation groups showed improved visual acuity. These results demonstrate the safety, survival, and functionality of the hESC-RPE monolayer transplantation in an RPE dysfunction rat model.

Cobalt-alloy implant debris induce HIF-1α hypoxia associated responses: a mechanism for metal-specific orthopedic implant failure.

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Lauryn Samelko

Full Text Available The historical success of orthopedic implants has been recently tempered by unexpected pathologies and early failures of some types of Cobalt-Chromium-Molybdenum alloy containing artificial hip implants. Hypoxia-associated responses to Cobalt-alloy metal debris were suspected as mediating this untoward reactivity at least in part. Hypoxia Inducible Factor-1α is a major transcription factor involved in hypoxia, and is a potent coping mechanism for cells to rapidly respond to changing metabolic demands. We measured signature hypoxia associated responses (i.e. HIF-1α, VEGF and TNF-α to Cobalt-alloy implant debris both in vitro (using a human THP-1 macrophage cell line and primary human monocytes/macrophages and in vivo. HIF-1α in peri-implant tissues of failed metal-on-metal implants were compared to similar tissues from people with metal-on-polymer hip arthroplasties, immunohistochemically. Increasing concentrations of cobalt ions significantly up-regulated HIF-1α with a maximal response at 0.3 mM. Cobalt-alloy particles (1 um-diameter, 10 particles/cell induced significantly elevated HIF-1α, VEGF, TNF-α and ROS expression in human primary macrophages whereas Titanium-alloy particles did not. Elevated expression of HIF-1α was found in peri-implant tissues and synovial fluid of people with failing Metal-on-Metal hips (n = 5 compared to failed Metal-on-Polymer articulating hip arthroplasties (n = 10. This evidence suggests that Cobalt-alloy, more than other metal implant debris (e.g. Titanium alloy, can elicit hypoxia-like responses that if unchecked can lead to unusual peri-implant pathologies, such as lymphocyte infiltration, necrosis and excessive fibrous tissue growths.

HEALING OF MICROVENOUS PTFE PROSTHESES IMPLANTED INTO THE RAT FEMORAL VEIN

NARCIS (Netherlands)

VANDERLEI, B; DIJK, F; JONGEBLOED, WL; ROBINSON, PH; Bartels, H.

44 PTFE prostheses (Gore-Tex(R); ID 1 mm) were implanted into rats' femoral veins by means of the sleeve anastomotic technique and were evaluated at regular intervals from 1 h up till 24 weeks after implantation by means of light and electron microscopy to study in detail their healing process. All

Establishment of 9L/F344 rat intracerebral glioma model of brain tumor stem cells

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Zong-yu XIAO

2015-04-01

Full Text Available Objective To establish the 9L/F344 rat intracerebral glioma model of brain tumor stem cells.  Methods Rat 9L gliosarcoma stem-like cells were cultured in serum-free suspension. The expression of CD133 and nestin were tested by immunohistochemistry. A total of 48 inbredline male F344 rats were randomly divided into 2 groups, and 9L tumor sphere cells and 9L monolayer cells were respectively implanted into the right caudate nucleus of F344 rats in 2 groups. Survival time was observed and determined using the method of Kaplan-Meier survival analysis. Fourteen days after implantation or when the rats were dying, their brains were perfused and sectioned for HE staining, and CD133 and nestin were detected by immunohistochemistry.  Results Rat 9L tumor spheres were formed with suspension culture in serum-free medium. The gliomas formed in both groups were invasive without obvious capsule. More new vessels, bleeding and necrosis could be detected in 9L tumor spheres group. The tumor cells in both groups were positive for CD133 and nestin. There was no significant difference in the expression of CD133 and nestin between 2 groups (P > 0.05, for all. According to the expression of nestin, the tumors formed by 9L tumor sphere cells were more invasive. The median survival time of the rats bearing 9L tumor sphere cells was 15 d (95%CI: 15.219-15.781, and the median survival time of the rats bearing 9L monolayer cells was 21 d (95%CI: 20.395-21.605. There was significant difference between 2 groups (χ2 = 12.800, P = 0.000.  Conclusions 9L/F344 rat intracerebral glioma model of brain tumor stem cells is successfully established, which provides a glioma model for the future research. DOI: 10.3969/j.issn.1672-6731.2015.04.012

Sustained glucagon-like peptide 1 expression from encapsulated transduced cells to treat obese diabetic rats.

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Moralejo, Daniel; Yanay, Ofer; Kernan, Kelly; Bailey, Adam; Lernmark, Ake; Osborne, William

2011-04-01

Obesity and type 2 diabetes (T2D) are two prevalent chronic diseases that have become a major public health concern in industrialized countries. T2D is characterized by hyperglycemia and islet beta cell dysfunction. Glucagon-like peptide 1 (GLP-1) promotes β cell proliferation and neogenesis and has a potent insulinotropic effect. Leptin receptor deficient male rats are obese and diabetic and provide a model of T2D. We hypothesized that their treatment by sustained expression of GLP-1 using encapsulated cells may prevent or delay diabetes onset. Vascular smooth muscle cells (VSMC) retrovirally transduced to secrete GLP-1 were seeded into TheraCyte(TM) encapsulation devices, implanted subcutaneously and rats were monitored for diabetes. Rats that received cell implants showed mean plasma GLP-1 level of 119.3 ± 10.2pM that was significantly elevated over control values of 32.4 ± 2.9pM (P<0.001). GLP-1 treated rats had mean insulin levels of 45.9 ± 2.3ng/ml that were significantly increased over control levels of 7.3±1.5ng/ml (P<0.001). In rats treated before diabetes onset elevations in blood glucose were delayed and rats treated after onset became normoglycemic and showed improved glucose tolerance tests. Untreated diabetic rats possess abnormal islet structures characterized by enlarged islets with α-cell infiltration and multifocal vacuolization. GLP-1 treatment induced normalization of islet structures including a mantle of α-cells and increased islet mass. These data suggest that encapsulated transduced cells may offer a potential long term treatment of patients. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Effects of pore size, implantation time, and nano-surface properties on rat skin ingrowth into percutaneous porous titanium implants.

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Farrell, Brad J; Prilutsky, Boris I; Ritter, Jana M; Kelley, Sean; Popat, Ketul; Pitkin, Mark

2014-05-01

The main problem of percutaneous osseointegrated implants is poor skin-implant integration, which may cause infection. This study investigated the effects of pore size (Small, 40-100 μm and Large, 100-160 μm), nanotubular surface treatment (Nano), and duration of implantation (3 and 6 weeks) on skin ingrowth into porous titanium. Each implant type was percutaneously inserted in the back of 35 rats randomly assigned to seven groups. Implant extrusion rate was measured weekly and skin ingrowth into implants was determined histologically after harvesting implants. It was found that all three types of implants demonstrated skin tissue ingrowth of over 30% (at week 3) and 50% (at weeks 4-6) of total implant porous area under the skin; longer implantation resulted in greater skin ingrowth (p skin integration with the potential for a safe seal. Copyright © 2013 Wiley Periodicals, Inc.

Closure of oroantral communication with buccal fat pad after removing bilateral failed zygomatic implants: A case report and 6-month follow-up.

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Peñarrocha-Oltra, David; Alonso-González, Rocio; Pellicer-Chover, Hilario; Aloy-Prósper, Amparo; Peñarrocha-Diago, María

2015-02-01

The aim of this study was to assess the use of buccal fat pad (BFP) technique as an option to close oroantral communications (OAC) after removing failed zygomatic implants in a patient with a severely resorbed maxilla, and to determine the degree of patient satisfaction. A 64-year-old woman presented recurrent sinusitis and permanent oroantral communication caused by bilateral failed zygomatic implants, 3 years after prosthetic loading. Zygomatic implants were removed previous antibiotic treatment and the BFP flap technique was used to treat the OAC and maxillary defect. The degree of patient satisfaction after treatment was assessed through a visual analogue scale (VAS). At 6-months follow-up, patient showed complete healing and good function and the results in terms of phonetics, aesthetics and chewing were highly rated by the patient. Key words:Bichat fat pad, buccal fat pad, zygomatic implants, oroantral communication.

Hard tissue formation of STRO-1-selected rat dental pulp stem cells in vivo.

NARCIS (Netherlands)

Yang, X.; Walboomers, X.F.; Beucken, J.J.J.P van den; Bian, Z.; Fan, M.; Jansen, J.A.

2009-01-01

The objective of this study was to examine hard tissue formation of STRO-1-selected rat dental pulp-derived stem cells, seeded into a calcium phosphate ceramic scaffold, and implanted subcutaneously in mice. Previously, STRO-1 selection was used to obtain a mesenchymal stem cell progenitor

Antinociceptive effect of intrathecal microencapsulated human pheochromocytoma cell in a rat model of bone cancer pain.

Science.gov (United States)

Li, Xiao; Li, Guoqi; Wu, Shaoling; Zhang, Baiyu; Wan, Qing; Yu, Ding; Zhou, Ruijun; Ma, Chao

2014-07-08

Human pheochromocytoma cells, which are demonstrated to contain and release met-enkephalin and norepinephrine, may be a promising resource for cell therapy in cancer-induced intractable pain. Intrathecal injection of alginate-poly (l) lysine-alginate (APA) microencapsulated human pheochromocytoma cells leads to antinociceptive effect in a rat model of bone cancer pain, and this effect was blocked by opioid antagonist naloxone and alpha 2-adrenergic antagonist rauwolscine. Neurochemical changes of cerebrospinal fluid are in accordance with the analgesic responses. Taken together, these data support that human pheochromocytoma cell implant-induced antinociception was mediated by met-enkephalin and norepinephrine secreted from the cell implants and acting at spinal receptors. Spinal implantation of microencapsulated human pheochromocytoma cells may provide an alternative approach for the therapy of chronic intractable pain.

Silver oxide-containing hydroxyapatite coating supports osteoblast function and enhances implant anchorage strength in rat femur.

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Eto, Shuichi; Miyamoto, Hiroshi; Shobuike, Takeo; Noda, Iwao; Akiyama, Takayuki; Tsukamoto, Masatsugu; Ueno, Masaya; Someya, Shinsuke; Kawano, Shunsuke; Sonohata, Motoki; Mawatari, Masaaki

2015-09-01

Antibacterial silver with hydroxyapatite (Ag-HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag-HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag-HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3-E1 cultured on the 3% Ag-HA-coated surface. These results were similar to those observed with silver-free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag-HA-coated surface. The anchorage strength of implants inserted into the femur of Sprague-Dawley (SD) rats was enhanced by coating the implants with 3% Ag-HA. On the 3% Ag-HA-coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag-HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag-HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 2).

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Piazza, Nicolo; Bleiziffer, Sabine; Brockmann, Gernot; Hendrick, Ruge; Deutsch, Marcus-André; Opitz, Anke; Mazzitelli, Domenico; Tassani-Prell, Peter; Schreiber, Christian; Lange, Rüdiger

2011-07-01

This study sought to review the acute procedural outcomes of patients who underwent transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation at the German Heart Center, Munich, and to summarize the existing literature on TAV-in-SAV implantation (n = 47). There are several case reports and small case series describing transcatheter aortic valve implantation for a failing surgical aortic valve bioprosthesis (TAV-in-SAV implantation). From January 2007 to March 2011, 20 out of 556 patients underwent a TAV-in-SAV implantation at the German Heart Center Munich. Baseline characteristics and clinical outcome data were prospectively entered into a dedicated database. The mean patient age was 75 ± 13 years, and the mean logistic European System for Cardiac Operative Risk Evaluation and Society of Thoracic Surgeons' Risk Model scores were 27 ± 13% and 7 ± 4%, respectively. Of the 20 patients, 14 had stented and 6 had stentless surgical bioprostheses. Most cases (12 of 20) were performed via the transapical route using a 23-mm Edwards Sapien prosthesis (Edwards Lifesciences, Irvine, California). Successful implantation of a TAV in a SAV with the patient leaving the catheterization laboratory alive was achieved in 18 of 20 patients. The mean transaortic valve gradient was 20.0 ± 7.5 mm Hg. None-to-trivial, mild, and mild-to-moderate paravalvular aortic regurgitation was observed in 10, 6, and 2 patients, respectively. We experienced 1 intraprocedural death following pre-implant balloon aortic valvuloplasty ("stone heart") and 2 further in-hospital deaths due to myocardial infarction. TAV-in-SAV implantation is a safe and feasible treatment for high-risk patients with failing aortic bioprosthetic valves and should be considered as part of the armamentarium in the treatment of aortic bioprosthetic valve failure. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

International Nuclear Information System (INIS)

Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

1987-01-01

Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance. (author)

Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

Energy Technology Data Exchange (ETDEWEB)

Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

1987-04-01

Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.

Sheep Hip Arthroplasty Model of Failed Implant Osseointegration

DEFF Research Database (Denmark)

Jakobsen, Thomas; Kold, Søren; Baas, Jørgen

2015-01-01

femoral condyles in ten sheep. The micromotion device consists of an anchor bearing a PMMA implant and a PE plug. During each gait cycle the PE plug will make the PMMA implant axially piston 0.5 mm. After 12 weeks of observation the bone specimens were harvested and a post-mortem control implant......Early secure stability of an implant is important for long-term survival. We examined whether micromotion of implants consistently would induce bone resorption and formation of a fibrous membrane and thereby prevent osseointegration. One micromotion implant was inserted into one of the medial...... was inserted into the contra-lateral medial femoral condyle. Histomorphometrical evaluation showed that the surface on the implant observed for 12 weeks was covered by fibrous tissue. The control implants were covered by lamellar bone. No difference was found with respect to the volume fraction of lamellar...

Improved ovulation rate and implantation in rats treated with royal jelly

African Journals Online (AJOL)

The ovaries and uteris of 12 mature female rats (Rattus norvegicus) were examined to determine the effect of commercial royal jelly on ovulation, ovarian weight and implantation rates. Rats were split in two groups of 6 each. Group one served as the treatment and group two the control. A daily dose of 25mg of royal jelly ...

Neuron cell positioning on polystyrene in culture by silver-negative ion implantation and region control of neural outgrowth

International Nuclear Information System (INIS)

Tsuji, Hiroshi; Sato, Hiroko; Baba, Takahiro; Ikemura, Shin'ichi; Gotoh, Yasuhito; Ishikawa, Junzo

2000-01-01

A new method to control the position of neuron cell attachment and extension region of neural outgrowth has been developed by using a pattering ion implantation with silver-negative ions into polystyrene dishes. This technique offers a promising method to form an artificially designed neural network in cell culture in vitro. Silver-negative ions were implanted into non-treated polystyrene dishes (NTPS) at conditions of 20 keV and 3x10 15 ions/cm 2 through a pattering mask, which had as many as 67 slits of 60 μm in width and 4 mm in length with a spacing of 60 μm. For cell culture in vitro, nerve cells of PC-12h (rat adrenal phechromocytoma) were used because they respond to a nerve growth factor (NGF). In the first 2 days in culture without NGF, we observed a selective cell attachment only to the ion-implanted region in patterning Ag - implanted polystyrene sample (p-Ag/NTPS). In another 2 days in culture with NGF, the nerve cells expanded neurites only over the ion-implanted region. For collagen-coated p-Ag/NTPS sample of which collagen was coated after the ion implantation (Collagen/p-Ag/NTPS), most nerve cells were also attached on the ion-implanted region. However, neurites expanded in both ion-implanted and unimplanted regions. The contact angle of NTPS decreased after the ion implantation from 86 deg. to 74 deg. . The region selectivity of neuron attachment and neurite extension is considered to be due to contact angle lowering by the ion implantation as radiation effect on the surface

Treatment of diabetic rats with encapsulated islets.

Science.gov (United States)

Sweet, Ian R; Yanay, Ofer; Waldron, Lanaya; Gilbert, Merle; Fuller, Jessica M; Tupling, Terry; Lernmark, Ake; Osborne, William R A

2008-12-01

Immunoprotection of islets using bioisolator systems permits introduction of allogeneic cells to diabetic patients without the need for immunosuppression. Using TheraCyte immunoisolation devices, we investigated two rat models of type 1 diabetes mellitus (T1DM), BB rats and rats made diabetic by streptozotocin (STZ) treatment. We chose to implant islets after the onset of diabetes to mimic the probable treatment of children with T1DM as they are usually diagnosed after disease onset. We encapsulated 1000 rat islets and implanted them subcutaneously (SQ) into diabetic biobreeding (BB) rats and STZ-induced diabetic rats, defined as two or more consecutive days of blood glucose>350 mg/dl. Rats were monitored for weight and blood glucose. Untreated BB rats rapidly lost weight and were euthanized at >20% weight loss that occurred between 4 and 10 days from implantation. For period of 30-40 days following islet implantation weights of treated rats remained steady or increased. Rapid weight loss occurred after surgical removal of devices that contained insulin positive islets. STZ-treated rats that received encapsulated islets showed steady weight gain for up to 130 days, whereas untreated control rats showed steady weight loss that achieved >20% at around 55 days. Although islet implants did not normalize blood glucose, treated rats were apparently healthy and groomed normally. Autologous or allogeneic islets were equally effective in providing treatment. TheraCyte devices can sustain islets, protect allogeneic cells from immune attack and provide treatment for diabetic-mediated weight loss in both BB rats and STZ-induced diabetic rats.

Antinociceptive Effect of Intrathecal Microencapsulated Human Pheochromocytoma Cell in a Rat Model of Bone Cancer Pain

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Xiao Li

2014-07-01

Full Text Available Human pheochromocytoma cells, which are demonstrated to contain and release met-enkephalin and norepinephrine, may be a promising resource for cell therapy in cancer-induced intractable pain. Intrathecal injection of alginate-poly (l lysine-alginate (APA microencapsulated human pheochromocytoma cells leads to antinociceptive effect in a rat model of bone cancer pain, and this effect was blocked by opioid antagonist naloxone and alpha 2-adrenergic antagonist rauwolscine. Neurochemical changes of cerebrospinal fluid are in accordance with the analgesic responses. Taken together, these data support that human pheochromocytoma cell implant-induced antinociception was mediated by met-enkephalin and norepinephrine secreted from the cell implants and acting at spinal receptors. Spinal implantation of microencapsulated human pheochromocytoma cells may provide an alternative approach for the therapy of chronic intractable pain.

Isolation, culture and intraportal transplantation of rat marrow stromal cell

International Nuclear Information System (INIS)

Wang Ping; Wang Jianhua; Yan Zhiping; Li Wentao; Lin Genlai; Hu Meiyu; Wang Yanhong

2004-01-01

Objective: To observe the tracing and evolution of marrow stromal cell (MSC) after intraportal transplantation into the liver of homogenous rats, and to provide experimental data for MSC differentiation to hepatocyte in vivo. Methods: The MSC was isolated from the leg bone marrow of adult SD rats, and purified by culture-expanded in vitro. Before transplantation, MSC was labeled with DAPI. Then 10 5 MSC were intraportally transplanted into the homogenous rat liver. Rats were killed at 2 hours and 1, 2, 3 and 4 weeks after transplantation. The cryosection samples of liver and lung were observed under fluorescence microscopy. Results: MSC in vitro culture had high ability of proliferation. Except 4 rats were dead because of abdominal bleeding or infection, other recipients were healthy until sacrificed. The implantation cells were detected by identifying the DAPI labeled MSC in the host livers, but not in the host lungs. Conclusion: Intraportal transplanted MSC could immigrate and survive in the host livers at least for 4 weeks. They could immigrate from the small branches of portal veins to hepatic parenchyma

Effect of alpha-lipoic acid on endometrial implants in an experimental rat model.

Science.gov (United States)

Pınar, Neslihan; Soylu Karapınar, Oya; Özcan, Oğuzhan; Özgür, Tümay; Bayraktar, Suphi

2017-10-01

To investigate the antioxidant and anti-inflammatory effects of alpha-lipoic acid (ALA) in the treatment of endometriosis in an experimental rat model by evaluating biochemical and histopathologic parameters. Experimental endometriosis was induced by the peritoneal implantation of autologous endometrial tissue. The rats were randomly divided into two groups with eight rats each. Group I was intraperitoneally administered ALA 100 mg/kg/day for 14 days. Group II was intraperitoneally administered saline solution at the same dosage and over the same period. Endometrial implant volume was measured in both groups both pre- and post-treatment. Tumor necrosis factor alpha (TNF-α) was measured in peritoneal fluid. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were assessed in serum. The implants were histopathologically evaluated. In the ALA group, the serum TOS and OSI levels, the endometrial implant volumes, the TNF-α levels in serum and peritoneal fluid, and the histopathologic scores were significantly lower compared to the control group (P < 0.05). Alpha-lipoic acid may have a therapeutic potential in the treatment of endometriosis due to its antioxidant and anti-inflammatory effects. © 2017 Société Française de Pharmacologie et de Thérapeutique.

Endothelial cell adhesion to ion implanted polymers

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Y; Kusakabe, M [SONY Corp., Tokyo (Japan); Lee, J S; Kaibara, M; Iwaki, M; Sasabe, H [RIKEN (Inst. of Physical and Chemical Research), Saitama (Japan)

1992-03-01

The biocompatibility of ion implanted polymers has been studied by means of adhesion measurements of bovine aorta endothelial cells in vitro. The specimens used were polystyrene (PS) and segmented polyurethane (SPU). Na{sup +}, N{sub 2}{sup +}, O{sub 2}{sup +} and Kr{sup +} ion implantations were performed at an energy of 150 keV with fluences ranging from 1x10{sup 15} to 3x10{sup 17} ions/cm{sup 2} at room temperature. The chemical and physical structures of ion-implanted polymers have been investigated in order to analyze their tissue compatibility such as improvement of endothelial cell adhesion. The ion implanted SPU have been found to exhibit remarkably higher adhesion and spreading of endothelial cells than unimplanted specimens. By contrast, ion implanted PS demonstrated a little improvement of adhesion of cells in this assay. Results of FT-IR-ATR showed that ion implantation broke the original chemical bond to form new radicals such as OH, ....C=O, SiH and condensed rings. The results of Raman spectroscopy showed that ion implantation always produced a peak near 1500 cm{sup -1}, which indicated that these ion implanted PS and SPU had the same carbon structure. This structure is considered to bring the dramatic increase in the extent of cell adhesion and spreading to these ion implanted PS and SPU. (orig.).

Vitamin E Phosphate Coating Stimulates Bone Deposition in Implant-related Infections in a Rat Model.

Science.gov (United States)

Lovati, Arianna B; Bottagisio, Marta; Maraldi, Susanna; Violatto, Martina B; Bortolin, Monica; De Vecchi, Elena; Bigini, Paolo; Drago, Lorenzo; Romanò, Carlo L

2018-06-01

Implant-related infections are associated with impaired bone healing and osseointegration. In vitro antiadhesive and antibacterial properties and in vivo antiinflammatory effects protecting against bone loss of various formulations of vitamin E have been demonstrated in animal models. However, to the best of our knowledge, no in vivo studies have demonstrated the synergistic activity of vitamin E in preventing bacterial adhesion to orthopaedic implants, thus supporting the bone-implant integration. The purpose of this study was to test whether a vitamin E phosphate coating on titanium implants may be able to reduce (1) the bacterial colonization of prosthetic implants and (2) bone resorption and osteomyelitis in a rat model of Staphylococcus aureus-induced implant-related infection. Twelve rats were bilaterally injected in the femurs with S aureus UAMS-1-Xen40 and implanted with uncoated or vitamin E phosphate-coated titanium Kirschner wires without local or systemic antibiotic prophylaxis. Eight rats represented the uninfected control group. A few hours after surgery, two control and three infected animals died as a result of unexpected complications. With the remaining rats, we assessed the presence of bacterial contamination with qualitative bioluminescence imaging and Gram-positive staining and with quantitative bacterial count. Bone changes in terms of resorption and osteomyelitis were quantitatively analyzed through micro-CT (bone mineral density) and semiquantitatively through histologic scoring systems. Six weeks after implantation, we found only a mild decrease in bacterial count in coated versus uncoated implants (Ti versus controls: mean difference [MD], -3.705; 95% confidence interval [CI], -4.416 to -2.994; p E-treated group compared with uncoated implants (knee joint: MD, -11.88; 95% CI, -16.100 to -7.664; p E-coated nails compared with the uncoated nails. These preliminary findings indicate that vitamin E phosphate implant coatings can exert a

Cortical neurogenesis in adult rats after ischemic brain injury: most new neurons fail to mature

Directory of Open Access Journals (Sweden)

Qing-quan Li

2015-01-01

Full Text Available The present study examines the hypothesis that endogenous neural progenitor cells isolated from the neocortex of ischemic brain can differentiate into neurons or glial cells and contribute to neural regeneration. We performed middle cerebral artery occlusion to establish a model of cerebral ischemia/reperfusion injury in adult rats. Immunohistochemical staining of the cortex 1, 3, 7, 14 or 28 days after injury revealed that neural progenitor cells double-positive for nestin and sox-2 appeared in the injured cortex 1 and 3 days post-injury, and were also positive for glial fibrillary acidic protein. New neurons were labeled using bromodeoxyuridine and different stages of maturity were identified using doublecortin, microtubule-associated protein 2 and neuronal nuclei antigen immunohistochemistry. Immature new neurons coexpressing doublecortin and bromodeoxyuridine were observed in the cortex at 3 and 7 days post-injury, and semi-mature and mature new neurons double-positive for microtubule-associated protein 2 and bromodeoxyuridine were found at 14 days post-injury. A few mature new neurons coexpressing neuronal nuclei antigen and bromodeoxyuridine were observed in the injured cortex 28 days post-injury. Glial fibrillary acidic protein/bromodeoxyuridine double-positive astrocytes were also found in the injured cortex. Our findings suggest that neural progenitor cells are present in the damaged cortex of adult rats with cerebral ischemic brain injury, and that they differentiate into astrocytes and immature neurons, but most neurons fail to reach the mature stage.

A comparative study of zinc, magnesium, strontium-incorporated hydroxyapatite-coated titanium implants for osseointegration of osteopenic rats

Energy Technology Data Exchange (ETDEWEB)

Tao, Zhou-Shan [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China); Zhou, Wan-Shu [Endocrine & Metabolic Diseases Unit, Affiliated Hospital of Guizhou Medical University, Guizhou 550001 (China); He, Xing-Wen [Department of Orthopaedic Surgery, Hangzhou Bay Hospital of Ningbo, 315000 (China); Liu, Wei [Department of Orthopaedic Surgery, Jingmen No. 1 People' s Hospital, Jingmen 44800, Hubei (China); Bai, Bing-Li; Zhou, Qiang; Huang, Zheng-Liang; Tu, Kai-kai; Li, Hang; Sun, Tao [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China); Lv, Yang-Xun [Department of Orthopaedic Surgery, Wenzhou Central Hospital, Wenzhou, Zhejiang 325000 (China); Cui, Wei [Sichuan Provincial Orthopedics Hospital, No. 132 West First Section First Ring Road, Chengdu, Sichuan 610000 (China); Yang, Lei, E-mail: tzs19900327@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical University, 109 Xueyuan Xi Road, Wenzhou, Zhejiang 325027 (China)

2016-05-01

Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), magnesium (Mg), and strontium (Sr) present a beneficial effect on bone growth, and positively affect bone regeneration. The aim of this study was to confirm the different effects of the fixation strength of Zn, Mg, Sr-substituted hydroxyapatite-coated (Zn-HA-coated, Mg-HA-coated, Sr-HA-coated) titanium implants via electrochemical deposition in the osteoporotic condition. Female Sprague–Dawley rats were used for this study. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group HA; group Zn-HA; group Mg-HA and group Sr-HA. Afterwards, all rats from groups HA, Zn-HA, Mg-HA and Sr-HA received implants with hydroxyapatite containing 0%, 10% Zn ions, 10% Mg ions, and 10% Sr ions. Implants were inserted bilaterally in all animals until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. All treatment groups increased new bone formation around the surface of titanium rods and push-out force; group Sr-HA showed the strongest effects on new bone formation and biomechanical strength. Additionally, there are significant differences in bone formation and push-out force was observed between groups Zn-HA and Mg-HA. This finding suggests that Zn, Mg, Sr-substituted hydroxyapatite coatings can improve implant osseointegration, and the 10% Sr coating exhibited the best properties for implant osseointegration among the tested coatings in osteoporosis rats. - Highlights: • Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. • However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), Magnesium(Mg), Strontium (Sr) present a benificial effect on bone

Freezing of Rat Tibiae at -20°C Does Not Affect the Mechanical Properties of Intramedullary Bone/Implant-Interface: Brief Report

Science.gov (United States)

Diefenbeck, Michael; Mückley, Thomas; Zankovych, Sergiy; Bossert, Jörg; Jandt, Klaus D; Schrader, Christian; Schmidt, Jürgen; Finger, Ulrich; Faucon, Mathilde

2011-01-01

Background: The effects of freezing-thawing cycles on intramedullary bone-implant interfaces have been studied in a rat model in mechanical pull-out tests. Implants: Twenty TiAl6V4 rods (Ø 0.8 mm, length 10 mm) implanted in rat tibiae Methods: 10 rats underwent bilateral tibial implantation of titanium rods. At eight weeks, the animals were sacrificed and tibiae harvested for biomechanical testing. Eight tibiae were frozen and stored at -20°C for 14 days, the remaining eight were evaluated immediately post-harvest. Pull-out tests were used to determine maximum force and interfacial shear strength. Results: There were no significant differences between fresh and those of the frozen-thawed group in maximum force or in interfacial shear strength. Conclusion: Frozen Storage of rat tibiae containing implants at -20° C has no effects on the biomechanical properties of Bone/ Implant interface. PMID:21760868

Differential behavioral outcomes following neonatal versus fetal human retinal pigment epithelial cell striatal implants in parkinsonian rats

DEFF Research Database (Denmark)

Russ, Kaspar; Flores, Joseph; Brudek, Tomasz

2017-01-01

Following the failure of a Phase II clinical study evaluating human retinal pigment epithelial (hRPE) cell implants as a potential treatment option for Parkinson's disease, speculation has centered on implant function and survival as possible contributors to the therapeutic outcomes. We recently ...

Outcomes of Ahmed Valve Implant Following a Failed Initial Trabeculotomy and Trabeculectomy in Refractory Primary Congenital Glaucoma

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Dave, Paaraj; Senthil, Sirisha; Choudhari, Nikhil; Sekhar, Garudadri Chandra

2015-01-01

Purpose: The aim was to report the outcome of Ahmed glaucoma valve (AGV) (New World Medical, Inc., Rancho Cucamonga, CA, USA) implantation as a surgical intervention following an initial failed combined trabeculotomy + trabeculectomy (trab + trab) in refractory primary congenital glaucoma (RPCG). Materials and Methods: Retrospective chart review of 11 eyes of 8 patients who underwent implantation of AGV (model FP8) for RPCG between 2009 and 2011. Prior trab + trab had failed in all the eyes. Success was defined as an intraocular pressure (IOP) >5 and ≤ 18 mmHg during examination under anesthesia with or without medications and without serious complications or additional glaucoma surgery. Results: The mean age at AGV implantation was 15.4 ± 4.9 months. The mean preoperative IOP was 28 ± 5.7 mmHg which reduced to 13.6 ± 3.4 mmHg postoperatively at the last follow-up (P < 0.0001). The number of topical antiglaucoma medications reduced from a mean of 2.6 ± 0.5 to 1.6 ± 0.9 postoperatively (P = 0.009). The definition of qualified success was met in 10 (90%) eyes. One eye developed a shallow anterior chamber with choroidal detachment at 1-week, which resolved spontaneously with medications. None of the eyes developed a hypertensive phase. One eye had a long tube resulting in tube corneal touch that required trimming of the tube. One eye developed tube retraction, which was treated with a tube extender. The mean follow-up was 17.9 ± 9.3 (6.2-35.4) months. Conclusion: Managing RPCG remains a challenge. AGV implant was successful in a significant proportion of cases. PMID:25624676

Effect of implantation of biodegradable magnesium alloy on BMP-2 expression in bone of ovariectomized osteoporosis rats

International Nuclear Information System (INIS)

Guo, Yue; Ren, Ling; Liu, Chang; Yuan, Yajiang; Lin, Xiao; Tan, Lili; Chen, Shurui; Yang, Ke; Mei, Xifan

2013-01-01

The study was focused on the implantation of a biodegradable AZ31 magnesium alloy into the femoral periosteal of the osteoporosis modeled rats. The experimental results showed that after 4 weeks implantation of AZ31 alloy in the osteoporosis modeled rats, the expression of BMP-2 in bone tissues of the rats was much enhanced, even higher than the control group, which should promote the bone formation and be beneficial for reducing the harmful effect of osteoporosis. Results of HE stains showed that the implantation of AZ31 alloy did not have obvious pathological changes on both the liver and kidney of the animal. - Highlights: • Mg alloy greatly increased expression of BMP-2 in osteoporosis modeled rat bone. • Mg alloy showed good biological safety. • Mg alloy is beneficial for reducing the symptom of osteoporosis

Biocompatibility of RealSeal, its primer and AH Plus implanted in subcutaneous connective tissue of rats

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Fabiana Soares Grecca

2011-02-01

Full Text Available OBJECTIVE: This study tested rat connective tissue response to RealSeal, RealSeal primer or AH Plus after 7, 15, 30, 60 and 90 days of implantation. MATERIAL AND METHODS: Thirty Wistar rats had subcutaneous sockets created on their back and received four implants each of polyethylene tubes containing one of the materials tested according to the groups: AH (AH Plus Sealer; RS (RealSeal Sealer; RP (RealSeal Primer; CG (control group - empty tube. After histological processing, sections were analyzed to identify the presence of neutrophils, lymphocytes and plasma cells, eosinophils, macrophages and giant cells, as well as fibrous capsule and abscesses, by an examiner using light microscope. Kruskal-Wallis and multiple-comparisons test were used for statistical analysis. Significance level was set at 5%. RESULTS: Lymphoplasmacytic infiltrate scores significantly higher than those of the control group were observed at 14 and 60 days in AH group, and at 90 days in RS group (p<0.05. There were no differences in terms of presence of macrophages, giant cells, eosinophils, neutrophils or fibrosis. AH Plus group scored higher for abscesses at 7 days than after any other period (p=0.031. RP group scored higher for lymphoplasmacytic infiltrate at 14 days than at 90 days (p=0.04. CONCLUSION: The main contribution of this study was to demonstrate that issues involved with tissue tolerance of a Resilon-containing sealer, RealSeal Sealer, cannot be attributed to its primer content.

Inhibition of Insulin like growth factor-I expression by chromatographic fraction of Polygonum hydropiper root reduces implantation preference in rat

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Pranjiv Goswami

2014-03-01

Major conclusions: The root of P. hydropiper contains compound(s with capability to modulate transcription and expression of IGF-I in rat uterus during early gestation. Down regulation of IGF-I results suggests that the phytocompound(s work through the ovarian steroid receptor(s resulting in an inhibition of decidual cell reaction and implantation.

Phenotypic characterization of mononuclear inflammatory cells following equine hydroxyapatite/collagen block grafting in rats

International Nuclear Information System (INIS)

Alsuwaiyan, Asim; Wang, Bing-Yan; Cohen, Robert E

2012-01-01

To measure the inflammatory changes associated with the implantation of an equine hydroxyapatite and collagen-containing block graft (eHAC block) in a rodent model system, an eHAC block graft was implanted subcutaneously in rats. Control groups included saline, turpentine oil, and human mineralized particulate allograft (hMPA). Animals were sacrificed and tissue samples obtained after three days, as well as after 1, 2, 4 and 8 weeks. A panel of immunologic probes was used to identify circulatory monocytic cells (ED1), resident mononuclear phagocytes (ED2), mononuclear phagocytes of lymphoid origin (ED3), expression of Ia antigen (OX6), T-cells (OX19), and B-cells (OX33). Immunocytochemical localization was performed and mononuclear cells localized with each immunologic probe counted. Rat sera obtained after eight weeks were used for nitrocellulose dot-blotting to assess circulating anti-equine immunoglobulins. Statistical analysis was performed using two-way analysis of variance, in conjunction with the Bonferroni correction to account for multiple comparisons. A transient increase in monocytes at 3 days and 1 week was observed in all groups, but was significantly higher in the turpentine control (P < 0.0001). A significant increase in the numbers of mononuclear cells detected with clones ED2 and ED3 was observed in specimens from the turpentine group, in contrast to the other groups in the 3 day to 4 week interval (P < 0.0001), as well as within all time periods (P < 0.0001). A statistically significant difference in numbers of ED3-positive cells was observed in the hMPA group compared to the saline and the eHAC block groups after one week (P < 0.0001). Significantly more OX6-positive cells were observed in the turpentine group, compared to other groups (3 days to 1 week; P < 0.0001). T-lymphocytes were essentially absent except for rats given turpentine (after 1 week). No B-lymphocyte response was found and none of the rats developed systemic anti

Evaluation of porous vitreous carbon or silicon implants by radiology in rat's skull; Avaliacao radiologica de implantes de carbono vitreo poroso ou silicone em cranio de ratos

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Vaccari-Mazzetti, Marcelo Paulo; Kobata, Celio Toshiro [Lusiada University of Santos, SP (Brazil). Hospital Defeitos da Face. Dept. of Surgery]. E-mail: mmgvaccari@ig.com.br; Fabiani, Paulo [Lusiada University of Santos, SP (Brazil). Dept. of Radiology; Martins, Dulce Maria Fonseca Soares [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Surgery. Div. of Plastic Surgery; Gomes, Paulo de Oliveira [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Surgery. Div. of Operatory Technique and Experimental Surgery; Martins, Jose Luiz [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Surgery. Div. of Pediatric Surgery

2008-07-01

Purpose: Evaluate by CT the use of porous vitreous carbon (PVC) and silicon (S) implants as the replacement bone in the craniofacial skeleton of rats. Methods: 40 rats divided in: Group A (n=20) PVC submitted to the implant of a fragment in skull. After the euthanasia, the animals were divided into two subgroups: A I: 10 animals, studied in the 7th postoperative day (P.O) and AII: 10 animals, studied in the 28th P.O. In group B, S, 20 rats were submitted to S implant in the skull. All other steps were identical to group A, with designation of subgroups BI and BII. CT with beams in axial cuts of 1 mm thickness to obtain 3-D information It was used Hounsfield scale for evaluate the radio density of the implant. They were used non parametric tests to analyze the results. Results: The 7th PO boss remained in the two groups, but for 28th PO, observed reduction in the volume of the implant in Group A, not observed in group B. CT studies noticed different radio densities around all of S prostheses (pseudo capsule), that do not appeared in CPV implants. The S has remained unchanged in the CT, but the CPV has had a modification in its radio density (p{<=}0,05), in all implants. Conclusion: In CT evaluation the implants of CPV have greater deformation that the S, which makes them not suitable for replacement of membranous bone in the rat skull. (author)

Characterization of the aspects of osteoprogenitor cell interactions with physical tetracalcium phosphate anchorage on titanium implant surfaces

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Ko, Chia-Ling [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan (China); Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Ya-Yuan; Liou, Cian-Hua [Alliance Global Technology Co., Ltd., Kaohsiung Medical Device Special Zone in Southern Taiwan Science Park, Kaohsiung 82151, Taiwan (China); Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan (China)

2015-04-01

Well-designed implants are used not only to modify the geometry of the implant but also to change the chemical properties of its surfaces. The present study aims to assess the biofunctional effects of tetracalcium phosphate (TTCP) particles as a physical anchor on the implant surface derived through sandblasting. The characteristics of the surface, cell viability, and alkaline phosphatase (ALP) activity toward osteoprogenitor cells (D1) were obtained. D1 cells were cultured on a plain surface that underwent sandblasting and acid etching (SLA) (control SLA group) and on different SLA surfaces with different anchoring TTCP rates (new test groups, M and H). The mean anchoring rates were 57% (M) and 74% (H), and the anchored thickness was estimated to range from 12.6 μm to 18.3 μm. Compared with the control SLA surface on Ti substrate, the new test groups with different TTCP anchoring rates (M and H) failed to improve cell proliferation significantly but had a well-differentiated D1 cell phenotype that enhanced ALP expression in the early stage of cell cultures, specifically, at day 7. Results suggest that the SLA surface with anchored TTCP can accelerate progenitor bone cell mineralization. This study shows the potential clinical application of the constructed geometry in TTCP anchorage on Ti for dental implant surface modification. - Highlights: • TTCP (tetracalcium phosphate) as a physical anchorage on implant is characterized. • Theoretical values of anchored thickness and capping areas were estimated. • TTCP anchored by sandblasting can accelerate progenitor bone cell mineralization. • TTCP anchored on SLA (sandblasting and acid etching) surface is a promising method.

Characterization of the aspects of osteoprogenitor cell interactions with physical tetracalcium phosphate anchorage on titanium implant surfaces

International Nuclear Information System (INIS)

Ko, Chia-Ling; Chang, Ya-Yuan; Liou, Cian-Hua; Chen, Wen-Cheng

2015-01-01

Well-designed implants are used not only to modify the geometry of the implant but also to change the chemical properties of its surfaces. The present study aims to assess the biofunctional effects of tetracalcium phosphate (TTCP) particles as a physical anchor on the implant surface derived through sandblasting. The characteristics of the surface, cell viability, and alkaline phosphatase (ALP) activity toward osteoprogenitor cells (D1) were obtained. D1 cells were cultured on a plain surface that underwent sandblasting and acid etching (SLA) (control SLA group) and on different SLA surfaces with different anchoring TTCP rates (new test groups, M and H). The mean anchoring rates were 57% (M) and 74% (H), and the anchored thickness was estimated to range from 12.6 μm to 18.3 μm. Compared with the control SLA surface on Ti substrate, the new test groups with different TTCP anchoring rates (M and H) failed to improve cell proliferation significantly but had a well-differentiated D1 cell phenotype that enhanced ALP expression in the early stage of cell cultures, specifically, at day 7. Results suggest that the SLA surface with anchored TTCP can accelerate progenitor bone cell mineralization. This study shows the potential clinical application of the constructed geometry in TTCP anchorage on Ti for dental implant surface modification. - Highlights: • TTCP (tetracalcium phosphate) as a physical anchorage on implant is characterized. • Theoretical values of anchored thickness and capping areas were estimated. • TTCP anchored by sandblasting can accelerate progenitor bone cell mineralization. • TTCP anchored on SLA (sandblasting and acid etching) surface is a promising method

Titanium Implant Impairment and Surrounding Muscle Cell Death Following High-Salt Diet: An In Vivo Study.

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Mathieu Lecocq

Full Text Available High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation program similar to that currently used in human care following arthroplasty.After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation.Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.

The effect of montelukast and antiadhesion barrier solution on the capsule formation after insertion of silicone implants in a white rat model.

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Yang, J-D; Kwon, O-H; Lee, J-W; Chung, H-Y; Cho, B-C; Park, H-Y; Kim, T-G

2013-01-01

Capsular contracture is one of the most severe complications that can occur in breast surgery following silicone implant insertion. The purpose of this study was to investigate the effect of montelukast and antiadhesion barrier solution (AABS) on reducing capsular formation and their possible synergism. This study was approved by the Animal Ethics Committee (Reference No. KNU 2012-33) and was conducted in accordance with the Kyungpook National University - Institutional Animal Care and Use Committee, Animal Ethics Committee. The experiments in this study were conducted in vivo in 4 groups of 24 rats. Following silicone implant insertion, the pocket was injected with different agents. Group I (control group) was given normal saline injections into the pocket and fed with pure water. Group II was given injections of AABS and fed with pure water. Group III was given injections of normal saline and the medication montelukast during the experimental period. Group IV was given injections of AABS and montelukast as postoperative medication. Peri-implant capsules were excised after 8 weeks and were evaluated for transparency, inflammatory cell content, capsule thickness, collagen pattern and TGF-β expression. The capsules in the experimental groups (i.e., groups II-IV) were significantly more transparent than those in group I (controls; p response occurring in the peri-implant capsules as they exhibited minor vascularization and a reduced number of mast cells and macrophages. The collagen patterns in the experimental groups were of a lower density than in the control group with the former showing a loose, tidy collagen pattern. The amounts of TGF-β and collagen I were higher in the control group than in the experimental groups. Group IV (the synergic effect group) had a more pronounced effect on all the parameters examined than that in groups II and III with separate drug administration. Montelukast and AABS reduced the thickness, the inflammatory cell infiltrate and the

Curcumin Implants, not Curcumin Diet Inhibits Estrogen-Induced Mammary Carcinogenesis in ACI Rats

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Bansal, Shyam S.; kausar, Hina; Vadhanam, Manicka V.; Ravoori, Srivani; Pan, Jianmin; Rai, Shesh N.; Gupta, Ramesh C.

2014-01-01

Curcumin is widely known for its anti-oxidant, anti-inflammatory and anti-proliferative activities in cell culture studies. However, poor oral bioavailability limited its efficacy in animal and clinical studies. Recently, we developed polymeric curcumin implants that circumvents oral bioavailability issues, and tested their potential against 17β-estradiol (E2)-mediated mammary tumorigenesis. Female ACI rats were administered curcumin either via diet (1,000 ppm) or via polymeric curcumin implants (two 2-cm; 200 mg each; 20% drug load) 4 days prior to grafting a subcutaneous E2 silastic implant (1.2 cm, 9 mg E2). Implants were changed after 4½ months to provide higher curcumin dose at the appearance of palpable tumors. The animals were euthanized after 3 weeks, 3 months and after the tumor incidence reached >80% (~6 months) in control animals. The curcumin administered via implants resulted in significant reduction in both the tumor multiplicity (2±1 vs 5±3; p=0.001) and tumor volume (184±198 mm3 vs 280±141 mm3; p=0.0283); the dietary curcumin, however, was ineffective. Dietary curcumin increased hepatic CYP1A and CYP1B1 activities without any effect on CYP3A4 activity whereas curcumin implants increased both CYP1A and CYP3A4 activities but decreased CYP1B1 activity in presence of E2. Since CYP1A and 3A4 metabolize most of the E2 to its non-carcinogenic 2-OH metabolite and CYP1B1 produces potentially carcinogenic 4-OH metabolite, favorable modulation of these CYPs via systemically delivered curcumin could be one of the potential mechanisms. The analysis of plasma and liver by HPLC showed substantially higher curcumin levels via implants versus the dietary route despite substantially higher dose administered. PMID:24501322

Implantation of Octacalcium Phosphate Stimulates both Chondrogenesis and Osteogenesis in the Tibia, but Only Osteogenesis in the Rat Mandible

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F. Sargolzaei Aval

2006-09-01

Full Text Available Statement of problem: It is not known whether endochondral and intramembranous bones have distinct biological characteristics. Octacalcium Phosphate (OCP, a hydroxyapatite precursor, has been reported to stimulate bone formation after being implanted in parietal bone defects of rats.Purpose: The present study was designed to investigate the response of endochondral and intramembranous bones to OCP implantation and to compare their biological characteristicsMaterials and Methods: Full-thickness standardized trephine defects were made in rat tibiae and mandibles and synthetic OCP was implanted into the defects. The biologic response was examined histologically to identify bone and cartilage formation.Results: Both chondrogenesis and osteogenesis were initiated in the tibia, 1 week after implantation of OCP and most of the cartilage was replaced by bone at week 2.However, the mandible only showed osteogenesis in response to OCP implantation at week 2, and no cartilage formation was associated with the osteogenesis.Conclusions: According to the results obtained in the present study, endochondral and intramembranous bones exhibit different biological responses to OCP implantation in rats.

Cannabis sativa smoke inhalation decreases bone filling around titanium implants: a histomorphometric study in rats.

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Nogueira-Filho, Getulio da R; Cadide, Tiago; Rosa, Bruno T; Neiva, Tiago G; Tunes, Roberto; Peruzzo, Daiane; Nociti, Francisco Humberto; César-Neto, João B

2008-12-01

Although the harmful effect of tobacco smoking on titanium implants has been documented, no studies have investigated the effects of cannabis sativa (marijuana) smoking. Thus, this study investigated whether marijuana smoke influences bone healing around titanium implants. Thirty Wistar rats were used. After anesthesia, the tibiae surface was exposed and 1 screw-shaped titanium implant was placed bilaterally. The animals were randomly assigned to one of the following groups: control (n = 15) and marijuana smoke inhalation (MSI) 8 min/d (n = 15). Urine samples were obtained to detect the presence of tetra-hidro-cannabinoid. After 60 days, the animals were killed. The degree of bone-to-implant contact and the bone area within the limits of the threads of the implant were measured in the cortical (zone A) and cancellous bone (zone B). Tetra-hidro-cannabinoid in urine was positive only for the rats of MSI group. Intergroup analysis did not indicate differences in zone A-cortical bone (P > 0.01), however, a negative effect of marijuana smoke (MSI group) was observed in zone B-cancellous bone for bone-to-implant contact and bone area (Student's t test, P smoke on bone healing may represent a new concern for implant success/failure.

Bone marrow mesenchymal stem cells differentiation and proliferation on the surface of coral implant

International Nuclear Information System (INIS)

Al-Salihi, K.A.; Samsudin, A.R.

2004-01-01

This study was designed to evaluate the ability of natural coral implant to provide an environment for marrow cells to differentiate into osteoblasts and function suitable for mineralized tissue formation. DNA content, alkaline phosptatase (ALP) activity, calcium (Ca) content and mineralized nodules, were measured at day 3, day 7 and day 14, in rat bone marrow stromal cells cultured with coral discs glass discs, while cells alone and coral disc alone cultured as control. DNA content, ALP activity, Ca content measurements showed no difference between coral, glass and cells groups at 3 day which were higher than control (coral disc alone), but there were higher asurement at day 7 and 14 in the cell cultured on coral than on glass discs, control cells and control coral discs. Mineralized nodules formation (both in area and number) was more predominant on the coral surface than in control groups. These results showed that natural coral implant provided excellent and favorable situation for marrow cell to differentiate to osteoblasts, lead to large amount of mineralized tissue formation on coral surface. This in vitro result could explain the rapid bone bonding of coral in vivo. (Author)

Influences of serum from ozone-exposed pregnant rats in an in vitro model of implantation

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In our previous studies, ozone (O3) exposure during implantation [gestational day (GD) 5 and 6)] in rats resulted in intrauterine growth restriction (IUGR), suggesting impairment of implantation with exposure. The aim of this study was to (1) determine if serum collected from pre...

Sub-meninges implantation reduces immune response to neural implants.

Science.gov (United States)

Markwardt, Neil T; Stokol, Jodi; Rennaker, Robert L

2013-04-15

Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability. Published by Elsevier B.V.

MRI and morphological observation in C6 glioma model rats and significance

International Nuclear Information System (INIS)

Zhou Ying; Yuan Bo; Wang Hao; Lu Jin; Yuan Changji; Ma Yue; Tong Dan; Zhang Kun; Gao Feng; Wu Xiaogang

2013-01-01

Objective: To establish stable and reliable rat C6 glioma model, and to perform MRI dynamic observation and pathomorphological observation in model animal brain, and to provide experimental basis for pharmaceutical research on anti-glioma drugs. Methods: The C6 glioma cells were cultured and 20 μL cultural fluid containing 1×10 6 C6 cells was sterotactically implanted into the left caudate nuclei in 10 male Wistar rats, respectively. The changes in the behavior of the rats after implantation were observed and recorded. MRI dynamic scanning was performed in 10 rats 2, 3 and 4 weeks after implantation and the brain tissues were taken for general and pathological examination when the 10 rats were naturally dead. The survival period of tumor-bearing rats was calculated. Results: 2 weeks after implantation the rats showed decreased activities and food intake, fur lackluster, and conjunctival congestion and so on; 3 weeks later, some rats appeared nerve symptoms such as body twitch, body hemiplegy, body distortion, rotation and so on. All the 10 rats died in 8-30 d. The median survival period of the tumor-bearing rats was 18 d, the average survival period was (18.3±7.3) d. The pathological examination showed that the tumor cells were arranged irregularly closely and karyokinesis was easy to see; tumor vascular tissue proliferation and tumor invasive growth into surrounding normal tissues were found. The expression of glial fibrillary acidic protein (GFAP) was positive in the tumors. Conclusion: A stable animal model of intracranial glioma is successfully established by stereotactic implantation of C6 cells into the rat caudate nucleus. The results of MRI dynamic observation and pathohistological observation on the model animal brain tissue. Can provide experimental basis for selecting the appropriate time window to perform the pharmaceutical research on anti-glioma drugs. (authors)

Fatty Acid Oxidation Is Preserved Regardless of Impaired Uptake in the Chronically Failing Rat Heart

OpenAIRE

TACHIKAWA, Hitoshi

2004-01-01

Fatty acid is used as a major fuel in the fasting heart, but the precise metabolism in the failing heart remains unknown. We assessed the hypothesis that the fatty acid metabolism might be impaired or delayed during heart failure. We examined in vivo kinetics of an isotope-labeled fatty acid analogue and its substrates as well as hemodynamic parameters and histopathological findings in a rat model of postmyocarditic dilated cardiomyopathy. Rat experimental autoimmune myocarditis (EAM) was ind...

Biocompatibility of a new nanomaterial based on calcium silicate implanted in subcutaneous connective tissue of rats

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Petrović Violeta

2012-01-01

Full Text Available The aim of the study was to investigate rat connective tissue response to a new calcium silicate system 7, 15, 30 and 60 days after implantation. Twenty Wistar albino male rats received two tubes half-filled with a new calcium silicate system (NCSS or MTA in subcutaneous tissue. The empty half of the tubes served as controls. Five animals were sacrificed after 7, 15, 30 and 60 days and samples of the subcutaneous tissue around implanted material were submitted to histological analysis. The intensity of inflammation was evaluated based on the number of inflammatory cells present. Statistical analysis was performed using one way ANOVA and Holm Sidak's multiple comparison tests. Mild to moderate inflammatory reaction was observed after 7, 15 and 30 days around a NCSS while mild inflammatory reaction was detected after 60 days of implantation. In the MTA group, mild to moderate inflammatory reaction was found after 7 and 15 days while mild inflammatory reaction was present after 30 and 60 days. There was no statistically significant difference in the intensity of inflammatory reactions between the tested materials and control groups in any experimental period (ANOVA p>0.05. Regarding the intensity of inflammatory reactions at different experimental periods, a statistically significant difference was observed between 7 and 30 days, 7 and 60 days and 15 to 60 days for both materials. For the controls, a statistically significant difference was found between 7 and 60 days and 15 and 60 days of the experiment (Holm Sidak < p 0.001. Subcutaneous tissue of rats showed good tolerance to a new calcium silicate system. Inflammatory reaction was similar to that caused by MTA. [Projekat Ministarstva nauke Republike Srbije, br. 172026

Establishing contact between cell-laden hydrogels and metallic implants with a biomimetic adhesive for cell therapy supported implants.

Science.gov (United States)

Barthes, Julien; Mutschler, Angela; Dollinger, Camille; Gaudinat, Guillaume; Lavalle, Philippe; Le Houerou, Vincent; Brian McGuinness, Garrett; Engin Vrana, Nihal

2017-12-15

For in-dwelling implants, controlling the biological interface is a crucial parameter to promote tissue integration and prevent implant failure. For this purpose, one possibility is to facilitate the establishment of the interface with cell-laden hydrogels fixed to the implant. However, for proper functioning, the stability of the hydrogel on the implant should be ensured. Modification of implant surfaces with an adhesive represents a promising strategy to promote the adhesion of a cell-laden hydrogel on an implant. Herein, we developed a peptidic adhesive based on mussel foot protein (L-DOPA-L-lysine) 2 -L-DOPA that can be applied directly on the surface of an implant. At physiological pH, unoxidized (L-DOPA-L-lysine) 2 -L-DOPA was supposed to strongly adhere to metallic surfaces but it only formed a very thin coating (less than 1 nm). Once oxidized at physiological pH, (L-DOPA-L-lysine) 2 -L-DOPA forms an adhesive coating about 20 nm thick. In oxidized conditions, L-lysine can adhere to metallic substrates via electrostatic interaction. Oxidized L-DOPA allows the formation of a coating through self-polymerization and can react with amines so that this adhesive can be used to fix extra-cellular matrix based materials on implant surfaces through the reaction of quinones with amino groups. Hence, a stable interface between a soft gelatin hydrogel and metallic surfaces was achieved and the strength of adhesion was investigated. We have shown that the adhesive is non-cytotoxic to encapsulated cells and enabled the adhesion of gelatin soft hydrogels for 21 days on metallic substrates in liquid conditions. The adhesion properties of this anchoring peptide was quantified by a 180° peeling test with a more than 60% increase in peel strength in the presence of the adhesive. We demonstrated that by using a biomimetic adhesive, for the application of cell-laden hydrogels to metallic implant surfaces, the hydrogel/implant interface can be ensured without relying on the

Experimental treatment of diabetic mice with microencapsulated rat islet cells transplantation

International Nuclear Information System (INIS)

Luo Yun; Xue Yilong; Li Yanling; Li Xinjian

2006-01-01

To observe treatment effects of diabetic mice with microcapsulated and non-microcapsulated rat islet cell transplantation, pancreas of SD rat was perfused with collagenase through cloledchus, and then the pancreatic tissues were isolated and digested. Histopaque-1077 was used to purify the digested pancreas. Islet cells were collected and implanted into the peritoneal cavity of diabetic mice. The isolated islets had a response upon glucose stimulation. When the microcapsulated islets and non- microcapsulated islets were transplanted into diabetic mices the high blood glucose level could be decreased to normal. The normal blood glucose level in the diabetic mice transpanted with microcapsulated islets could be maintained for over 30 days,but it could be mainlained only for 2-3 days in the diabetic mice transplanted with non-microcapsulated islets. Thus it is believed that microcapsulated islet cell transplantation exerts good effect on diabetic mice and the microcapsules possessed good immunoisolating function. (authors)

Expression of rat class I major histocompatibility complex (MHC) alloantigens and hepatocytes and hepatoma cells

International Nuclear Information System (INIS)

Hunt, J.M.; Desai, P.A.; Chakraborty, S.

1986-01-01

Altered expression of Class I MHC alloantigens has been reported for murine tumors, and may be associated with the tumorigenic phenotype of tumor cells. To characterize MHC Class I alloantigen expression on a chemically-induced transplantable rat hepatoma cell line, 17X, derived from a (WF x F344) F 1 rat, polyvalent anti-F344 and anti-WF rat alloantisera were first used to immunoprecipitate the rat RT1.A Class I MHC alloantigens expressed on primary (WF x F344) F 1 hepatocyptes in short-term monolayer cultures. Two-dimensional isoelectric focusing and SDS-PAGE of immunoprecipitates from 35 S-methionine-labeled (WF x F344) F 1 hepatocytes clearly resolved the RT1.A/sup u/ (WF) and RT1.A/sup LvI/ (F344) parental alloantigens. Identical radiolabeling and immunoprecipitation failed to detect either parental alloantigen on the 17X hepatoma cells. However, indirect immunofluorescence and immunoblot analyses demonstrated the presence of parental alloantigens on the 17X cells. Immunization of F344 rats but not of WF rats with 17X cells resulted in antibodies cytotoxic for normal (WF X F344) F 1 spleen cells in the presence of complement. These findings indicate that a combination of detection techniques will be necessary to characterize altered alloantigen expression on rat hepatoma cells

Distinct angiotensin II receptor in primary cultures of glial cells from rat brain

International Nuclear Information System (INIS)

Raizada, M.K.; Phillips, M.I.; Crews, F.T.; Sumners, C.

1987-01-01

Angiotensin II (Ang-II) has profound effects on the brain. Receptors for Ang-II have been demonstrated on neurons, but no relationship between glial cells and Agn-II has been established. Glial cells (from the hypothalamus and brain stem of 1-day-old rat brains) in primary culture have been used to demonstrate the presence of specific Ang-II receptors. Binding of 125 I-Ang-II to glial cultures was rapid, reversible, saturable, and specific for Ang-II. The rank order of potency of 125 I-Ang-II binding was determined. Scatchard analysis revealed a homogeneous population of high-affinity binding sites with a B/sub max/ of 110 fmol/mg of protein. Light-microscopic autoradiography of 125 I-Ang-II binding supported the kinetic data, documenting specific Ang-II receptors on the glial cells. Ang-II stimulated a dose-dependent hydrolysis of phosphatidylinositols in glial cells, an effect mediated by Ang-II receptors. However, Ang-II failed to influence [ 3 H] norepinephrine uptake, and catecholamines failed to regulate Ang-II receptors, effects that occur in neurons. These observations demonstrate the presence of specific Ang-II receptors on the glial cells in primary cultures derived from normotensive rat brain. The receptors are kinetically similar to, but functionally distinct from, the neuronal Ang-II receptors

Histology study on the dorsal root ganglia of rats with 125I seed brachytherapy at intervertebral foramen

International Nuclear Information System (INIS)

Zhang Wenyi; Wang Huixing; Ding Yanqiu; Qu Ximei; Wang Liqin; Liu Zhongchao; Cui Songye; Jiao Ling

2012-01-01

Objective: To investigate the effect of the histological changes on rat dorsal root ganglia (DRG) after 125 I seed brachytherapy.Methods Twelve adult male Sprague-Dawley rats (150-180 g each) were randomly divided into 6 groups, 125 I seeds with different activities of 0 (Titanium shell), 14.8, 18.5, 22.2, 25.9 and 29.6 MBq were implanted to 6 groups of rats respectively and the behavioral changes of rats were observed. The rats were killed in different periods after implantation,the morphological changes in DRG and surrounding muscle tissue were observed with an Olympus BX51 optical microscope and then the irradiation doses were estimated. Results: After 125 I seed implantation, the movement function of rats was not affected and the weight of rats gained after 7 days. After the titanium shell implantation, very few mild swelling was induced in neuroganglion cells that still had clear nucleolus and normal cytoplasm. At 14 days after 18.5 MBq seed implantation, cell swelling was more serious and cell dehydrating, nuclear condensation and nuclear fragmentation appeared after 30 days. At 60 days after 29.6 MBq of seed implantation, nuclear dissolution and cytoplasmic shrinkage were induced in a large number of cells.In general, the severity of fibrosis was aggravated with the time post-irradiation and the dose in the muscles around the ganglion. Conclusions: After 125 I seed implantation,the injury degree of DRG tissue is dose-dependent, and the 125 I seed irradiation would have analgesic effect on releasing intractable pain. (authors)

High dose infusion of activated protein C (rhAPC) fails to improve neuronal damage and cognitive deficit after global cerebral ischemia in rats.

Science.gov (United States)

Brückner, Melanie; Lasarzik, Irina; Jahn-Eimermacher, Antje; Peetz, Dirk; Werner, Christian; Engelhard, Kristin; Thal, Serge C

2013-09-13

Recent studies demonstrated anticoagulatory, antiinflammatory, antiapoptotic, and neuroprotective properties of activated protein C (APC) in rodent models of acute neurodegenerative diseases, suggesting APC as promising broad acting therapeutic agent. Unfortunately, continuous infusion of recombinant human APC (rhAPC) failed to improve brain damage following cardiac arrest in rats. The present study was designed to investigate the neuroprotective effect after global cerebral ischemia (GI) with an optimized infusion protocol. Rats were subjected to bilateral clip occlusion of the common carotid arteries (BCAO) and controlled hemorrhagic hypotension to 40 mm Hg for 14 min and a subsequent 5h-infusion of rhAPC (2mg/kg bolus+6 mg/kg/h continuous IV) or vehicle (0.9% NaCl). The dosage was calculated to maintain plasma hAPC activity at 150%. Cerebral inflammation, apoptosis and neuronal survival was determined at day 10. rhAPC infusion did not influence cortical cerebral perfusion during reperfusion and failed to reduce neuronal cell loss, microglia activation, and caspase 3 activity. Even an optimized rhAPC infusion protocol designed to maintain a high level of APC plasma activity failed to improve the sequels following GI. Despite positive reports about protective effects of APC following, e.g., ischemic stroke, the present study supports the notion that infusion of APC during the early reperfusion phase does not result in sustained neuroprotection and fails to improve outcome after global cerebral ischemia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces in rats.

Science.gov (United States)

Kung, S; Devlin, H; Fu, E; Ho, K-Y; Liang, S-Y; Hsieh, Y-D

2011-02-01

The enhancing effects of chitosan on activation of platelets and differentiation of osteoprogenitor cells have been demonstrated in vitro. The purpose of this study was to evaluate the in vivo osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces. Chitosan-collagen composites containing chitosan of different molecular weights (450 and 750 kDa) were wrapped onto titanium implants and embedded into the subcutaneous area on the back of 15 Sprague-Dawley rats. The control consisted of implants wrapped with plain collagen type I membranes. Implants and surrounding tissues were retrieved 6 wks after surgery and identified by Alizarin red and Alcian blue whole mount staining. The newly formed structures in the test groups were further analyzed by Toluidine blue and Masson-Goldner trichrome staining, and immunohistochemical staining with osteopontin and alkaline phosphotase. The bone formation parameters of the new bone in the two test groups were measured and compared. New bone formed ectopically in both chitosan-collagen groups, whereas no bone induction occurred in the negative control group. These newly formed bone-like structures were further confirmed by immunohistochemical staining. Comparison of bone parameters of the newly induced bone revealed no statistically significant differences between the 450 and 750 kDa chitosan-collagen groups. Our results demonstrated that chitosan-collagen composites might induce in vivo new bone formation around pure titanium implant surfaces. Different molecular weights of chitosan did not show significantly different effects on the osteoinductive potential of the test materials. © 2010 John Wiley & Sons A/S.

Hollow fiber: a biophotonic implant for live cells

Science.gov (United States)

Silvestre, Oscar F.; Holton, Mark D.; Summers, Huw D.; Smith, Paul J.; Errington, Rachel J.

2009-02-01

The technical objective of this study has been to design, build and validate biocompatible hollow fiber implants based on fluorescence with integrated biophotonics components to enable in fiber kinetic cell based assays. A human osteosarcoma in vitro cell model fiber system has been established with validation studies to determine in fiber cell growth, cell cycle analysis and organization in normal and drug treated conditions. The rationale for implant development have focused on developing benchmark concepts in standard monolayer tissue culture followed by the development of in vitro hollow fiber designs; encompassing imaging with and without integrated biophotonics. Furthermore the effect of introducing targetable biosensors into the encapsulated tumor implant such as quantum dots for informing new detection readouts and possible implant designs have been evaluated. A preliminary micro/macro imaging approach has been undertaken, that could provide a mean to track distinct morphological changes in cells growing in a 3D matrix within the fiber which affect the light scattering properties of the implant. Parallel engineering studies have showed the influence of the optical properties of the fiber polymer wall in all imaging modes. Taken all together, we show the basic foundation and the opportunities for multi-modal imaging within an in vitro implant format.

Gentamicin coating of plasma chemical oxidized titanium alloy prevents implant-related osteomyelitis in rats.

Science.gov (United States)

Diefenbeck, M; Schrader, C; Gras, F; Mückley, T; Schmidt, J; Zankovych, S; Bossert, J; Jandt, K D; Völpel, A; Sigusch, B W; Schubert, H; Bischoff, S; Pfister, W; Edel, B; Faucon, M; Finger, U

2016-09-01

Implant related infection is one of the most feared and devastating complication associated with the use of orthopaedic implant devices. Development of anti-infective surfaces is the main strategy to prevent implant contamination, biofilm formation and implant related osteomyelitis. A second concern in orthopaedics is insufficient osseointegration of uncemented implant devices. Recently, we reported on a macroporous titanium-oxide surface (bioactive TiOB) which increases osseointegration and implant fixation. To combine enhanced osseointegration and antibacterial function, the TiOB surfaces were, in addition, modified with a gentamicin coating. A rat osteomyelitis model with bilateral placement of titanium alloy implants was employed to analyse the prophylactic effect of gentamicin-sodiumdodecylsulfate (SDS) and gentamicin-tannic acid coatings in vivo. 20 rats were randomly assigned to four groups: (A) titanium alloy; PBS inoculum (negative control), (B) titanium alloy, Staphylococcus aureus inoculum (positive control), (C) bioactive TiOB with gentamicin-SDS and (D) bioactive TiOB plus gentamicin-tannic acid coating. Contamination of implants, bacterial load of bone powder and radiographic as well as histological signs of implant-related osteomyelitis were evaluated after four weeks. Gentamicin-SDS coating prevented implant contamination in 10 of 10 tibiae and gentamicin-tannic acid coating in 9 of 10 tibiae (infection prophylaxis rate 100% and 90% of cases, respectively). In Group (D) one implant showed colonisation of bacteria (swab of entry point and roll-out test positive for S. aureus). The interobserver reliability showed no difference in the histologic and radiographic osteomyelitis scores. In both gentamicin coated groups, a significant reduction of the histological osteomyelitis score (geometric mean values: C = 0.111 ± 0.023; D = 0.056 ± 0.006) compared to the positive control group (B: 0.244 ± 0.015; p < 0.05) was observed. The

Isolated rat dental pulp cell culture and transplantation with an alginate scaffold.

Science.gov (United States)

Fujiwara, Shiro; Kumabe, Shunji; Iwai, Yasutomo

2006-05-01

Many studies have been conducted on tissue stem cells in the field of regenerative medicine, and cultured dental pulp mesenchymal cells have been reported to secrete dentin matrix. In the present study we used alginate as a scaffold to transplant subcultured rat dental-pulp-derived cells subcutaneously into the back of nude mice. We found that when beta-glycerophosphate was added to the culture medium, the mRNA of the dentin sialophosphoprotein (DSPP) gene coding dentin sialoprotein (DSP) and dentin phosphoprotein (DPP) was expressed, and an increase in alkaline phosphatase, an early marker of odontoblast differentiation, was also demonstrated. Six weeks after implantation, subcutaneous formation of radiopaque calcified bodies was observed in situ. Immunohistochemical and fine structure studies identified expression of type I collagen, type III collagen, and DSP in the mineralizing transplants, and isolated odontoblast-like cells began to form dentin-like hard tissue formation. Scattered autolyzing apoptotic cells were also observed in the transplants. The study showed that subcultured rat dental-pulp-derived cells actively differentiate into odontoblast-like cells and induce calcification in an alginate scaffold.

Biodegradable Magnesium (Mg) Implantation Does Not Impose Related Metabolic Disorders in Rats with Chronic Renal Failure

Science.gov (United States)

Wang, Jiali; Xu, Jiankun; Liu, Waiching; Li, Yangde; Qin, Ling

2016-05-01

Mg and its alloys have been considered as one of the most promising biodegradable medical devices, but it was still unclear whether hypermagnesemia involved health risks would occur in persons with kidney disease due to their deteriorated kidney function for Mg ions excretion from their body. In this study, we established a chronic renal failure (CRF) model in rats induced by adenine administration prior to Mg implantation, aiming to predict if CRF patients are suitable for the use of Mg implants. The results showed that Mg levels in serum, urine, feces and internal organs had no significant changes after Mg implantation for both normal and CRF rats. Biochemical indices detection and histopathological analysis in kidney, liver and heart tissue confirmed that Mg implants did not induce any extra damage in animals even with renal failure. Our study indicates that Mg based orthopaedic medical device may be considered for use in CRF patients without biosafety concerns.

Lymphoscintigraphy and autologous stem cell implantation

International Nuclear Information System (INIS)

Peña, Yamile; Batista, Juan F.; Perera, Alejandro; Torres, Leonel A.; Sánchez, Elvia L.; Sánchez, Yolaine; Ducat, Luis; Prats, Anais; Hernández, Porfirio; Romero, Susana; Goicochea, Pedro; Quintela, Ana M.

2016-01-01

Lymphoscintigraphy is the criterion standard technique for the diagnosis of lymphedema. Advances of the application of autologous hematopoietic stem cells in ischemic disorders of lower limbs have increased the attention of researchers in this field. Aim: To determine the usefulness of lymphoscintigraphy for the assessment the efficacy of autologous stem cell implantation in patients with chronic lymphedema of the upper and lower limbs. Methods: Sixty-five patients were included. Clinical evaluation and lymphoscintigraphy were performed before and six months after stem cells implantation. The stem cells implantations were carried out by multiple superficial and deep injections in the trajectory of the lymphatic vessels and also in the inguinal region. A volume of 0.75 to 1.00 mL of cell suspension (1.0-2.2 x 109 stem cells) was administered in each injection site. Lymphoscintigraphy: Whole-body scans were acquired at 20 minutes, 1 hour, and 3 hours after administration of 185 to 259 MBq (5–7mCi) of 99m Tc-albumin nanocolloids in the interdigital space of both limbs. The anatomy and function of the lymphatic system were evaluated. Results: Functional assessment before implantation of stem cells showed that 69.2% of the patients had severe lymphatic insufficiency. The 61.5% of patients showed clinical improvement, confirmed by the results of the lymphoscintigraphy. The 46.1% of the cases evaluated showed a clear improvement. The study showed that the isotopic lymphography can evaluate the therapeutic response and its intensity. Conclusion: Lymphoscintigraphy is a useful technique for the evaluation and monitoring of autologous stem cell transplantation in patients with chronic lymphedema. (author)

Cell adhesion control by ion implantation into extra-cellular matrix

International Nuclear Information System (INIS)

Suzuki, Yoshiaki; Kusakabe, Masahiro; Kaibara, Makoto; Iwaki, Masaya; Sasabe, Hiroyuki; Nishisaka, Tsuyoshi

1994-01-01

Cell adhesion control of polymer surfaces by ion implantation into polymers and extra-cellular matrix has been studied by means of in vitro adhesion measurements of the carcinoma of the cervix (HeLa cell). The specimens used were polystyrene (PS), oxygen plasma treated polystyrene (PS-O), extra-cellular matrix (Collagen: Type I) coated polystyrene (PS-C), and gelatin coated polystyrene (PS-G). Ne + , Na + , and Ar + implantations were performed with a fluence of 1x10 15 ions/cm 2 at energies of 50, 100 and 150 keV. The chemical and physical structures of ion implanted specimens have been investigated by Fourier transform infrared spectroscopy (FT-IR-ATR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Ion implanted PS demonstrated a dramatic improvement of adhesion of HeLa cell. HeLa cell adhered only to ion implanted circular domains of a diameter about 0.1 mm on PS. By contrast, ion implanted PS-C, PS-G and PS-O domains inhibited the cell adhesion. These phenomena were observed on Ne + , Na + , and Ar + implanted specimens at energies of 50, 100, and 150 keV. Ion implantation broke the original chemical bonds to form new radicals such as =C=O, condensed rings, C-C, C-O and OH radical. Ion implanted PS had a large amount of new radicals compared with that of PS-C, PS-G and PS-O. Ion implantation broke NH and NH 3 bonds originating from amino acid in PS-C and PS-G. OH and =C=O caused by oxygen treatment in PS-O were also destroyed by ion implantation. It is concluded that cell adhesion to ion implanted PS was caused by carbon structure and new radicals induced by ion implantation. The inhibition of HeLa cell adhesion on PS-C, PS-G and PS-O was caused by the destruction of cell adhesion properties of amino acid, OH and =C=O by radiation effects. ((orig.))

A novel knee prosthesis model of implant-related osteo- myelitis in rats

DEFF Research Database (Denmark)

Søe, Niels H.; Jensen, Nina Vendel; Nürnberg, Birgit Meinecke

2012-01-01

There have been numerous reports of animal models of osteomyelitis. Very few of these have been prosthesis models that imitate human conditions. We have developed a new rat model of implant-related osteomyelitis that mimics human osteomyelitis, to investigate the pathology of infection after...

Study of the boron levels in serum after implantation of different ratios nano-hexagonal boron nitride–hydroxy apatite in rat femurs

Energy Technology Data Exchange (ETDEWEB)

Atila, Alptug, E-mail: alptugatila@yahoo.com [Department of Analytical Chemistry, Faculty of Pharmacy, Ataturk University, Erzurum 25240 (Turkey); Halici, Zekai; Cadirci, Elif [Department of Pharmacology, Faculty of Medicine, Ataturk University, Erzurum 25240 (Turkey); Karakus, Emre [Department of Pharmacology and Toxicology, School of Veterinary Medicine, Ataturk University, Erzurum 25240 (Turkey); Palabiyik, Saziye Sezin [Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Ataturk University, Erzurum 25240 (Turkey); Ay, Nuran [Department of Material Science and Engineering, Faculty of Engineering, Anadolu University, Eskisehir 26555 (Turkey); Bakan, Feray [Sabancı University Nanotechnology Research and Application Center (SUNUM), Istanbul 34956 (Turkey); Yilmaz, Sahin [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul 34755 (Turkey)

2016-01-01

ABSTRACT: Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN–HA composites in rat femurs. All rats were (n = 126) divided into five experimental groups (n = 24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100HA (Group2), femoral defect + %2.5hBN + %97.5HA (Group3), femoral defect + %5hBN + %95HA (Group4), femoral defect + %10hBN + %90 HA (Group5), femoral defect + %100hBN (Group6). The femoral defect was created in the distal femur (3 mm drill-bit). Each implant group was divided into four different groups (n = 24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN–HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN–HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers. - Highlights: • Nano-hBN–HA composites are new targets for biomaterial and implant bioengineers. • Serum boron levels were researched after implantation of nano-hBN–HA composites. • Implantation of hBN–HA composite did not result in increased serum boron levels. • The use of boron in composite form with HA did not change the stability of the implant.

Evaluation of egg white ovomucin-based porous scaffold as an implantable biomaterial for tissue engineering.

Science.gov (United States)

Carpena, Nathaniel T; Abueva, Celine D G; Padalhin, Andrew R; Lee, Byong-Taek

2017-10-01

Studies have shown the technological and functional properties of ovomucin (OVN) in the food-agricultural industry. But research has yet to explore its potential as an implantable biomaterial for tissue engineering and regenerative medicine. In this study we isolated OVN from egg white by isoelectric precipitation and fabricated scaffolds with tunable porosity by utilizing its foaming property. Gelatin a known biocompatible material was introduced to stabilize the foams, wherein different ratios of OVN and gelatin had a significant effect on the degree of porosity, pore size and stability of the formed hydrogels. The porous scaffolds were crosslinked with EDC resulting in stable scaffolds with prolonged degradation. Improved cell proliferation and adhesion of rat bone marrow-derived mesenchymal stem cells were observed for OVN containing scaffolds. Although, scaffolds with 75% OVN showed decrease in cell proliferation for L929 fibroblast type of cells. Further biocompatibility assessment as implant material was determined by subcutaneous implantation in rats of selected scaffold. H&E staining showed reasonable vascularization over time and little evidence of severe fibrosis at the implant site. Persistent polarization of classically activated macrophage was not observed, potentially reducing inflammatory response, and showed increased expression of alternatively activated macrophage cells that is favorable for tissue repair. Analysis of IgE levels in rat serum after implantation indicated minimal and resolvable allergic response to the OVN implants. The results demonstrate OVN as an acceptable implant scaffold that could provide new opportunities as an alternative natural biocompatible and functional biomaterial in various biomedical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2107-2117, 2017. © 2016 Wiley Periodicals, Inc.

Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

International Nuclear Information System (INIS)

He, Shu-Fang; Jin, Shi-Yun; Wu, Hao; Wang, Bin; Wu, Yun-Xiang; Zhang, Shu-Jie; Irwin, Michael G.; Wong, Tak-Ming; Zhang, Ye

2015-01-01

Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

Morphine preconditioning confers cardioprotection in doxorubicin-induced failing rat hearts via ERK/GSK-3β pathway independent of PI3K/Akt

Energy Technology Data Exchange (ETDEWEB)

He, Shu-Fang; Jin, Shi-Yun; Wu, Hao; Wang, Bin; Wu, Yun-Xiang [Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China); Zhang, Shu-Jie [Department of Ultrasound, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China); Irwin, Michael G.; Wong, Tak-Ming [Department of Anesthesiology, University of Hong Kong (Hong Kong); Zhang, Ye, E-mail: zhangye_hassan@aliyun.com [Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei 230601 (China)

2015-11-01

Preconditioning against myocardial ischemia–reperfusion (I/R) injury can be suppressed in some pathological conditions. This study was designed to investigate whether morphine preconditioning (MPC) exerts cardioprotection in doxorubicin (DOX)-induced heart failure in rats and the mechanisms involved. Phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt), extracellular signal-regulated kinase (ERK) and glycogen synthase kinase (GSK)-3β pathways were examined. Normal and DOX-induced failing rat hearts were subjected to I/R injury using a Langendorff perfusion system with or without MPC or ischemic preconditioning (IPC). The PI3K inhibitor (wortmannin) or ERK inhibitor (PD98059) was infused before MPC. In normal hearts, both MPC and IPC significantly reduced infarct size and the rise in lactate dehydrogenase (LDH) level caused by I/R injury. Pretreatment with wortmannin or PD98059 abrogated the protective effects of MPC and suppressed the phosphorylation of Akt, ERK and GSK-3β. In failing rat hearts, however, MPC retained its cardioprotection while IPC did not. This protective effect was abolished by PD98059 but not wortmannin. MPC increased the level of p-ERK rather than p-Akt. The phosphorylation of GSK-3β induced by MPC was reversed by PD98059 only. IPC did not elevate the expression of p-ERK, p-Akt and p-GSK-3β in failing rat hearts. We conclude that MPC is cardioprotective in rats with DOX-induced heart failure while IPC is not. The effect of MPC appears to be mediated via the ERK/GSK-3β pathway independent of PI3K/Akt. - Highlights: • Morphine and ischemic preconditioning are cardioprotective in normal rat hearts. • Ischemic preconditioning fails to confer cardioprotection in rats with heart failure. • Morphine retains cardioprotection in doxorubicin-induced heart failure. • Morphine exerts cardioprotection via the ERK/GSK-β pathway independent of PI3K/Akt.

Use of micro-CT-based finite element analysis to accurately quantify peri-implant bone strains: a validation in rat tibiae.

Science.gov (United States)

Torcasio, Antonia; Zhang, Xiaolei; Van Oosterwyck, Hans; Duyck, Joke; van Lenthe, G Harry

2012-05-01

Although research has been addressed at investigating the effect of specific loading regimes on bone response around the implant, a precise quantitative understanding of the local mechanical response close to the implant site is still lacking. This study was aimed at validating micro-CT-based finite element (μFE) models to assess tissue strains after implant placement in a rat tibia. Small implants were inserted at the medio-proximal site of 8 rat tibiae. The limbs were subjected to axial compression loading; strain close to the implant was measured by means of strain gauges. Specimen-specific μFE models were created and analyzed. For each specimen, 4 different models were created corresponding to different representations of the bone-implant interface: bone and implant were assumed fully osseointegrated (A); a low stiffness interface zone was assumed with thickness of 40 μm (B), 80 μm (C), and 160 μm (D). In all cases, measured and computational strains correlated highly (R (2) = 0.95, 0.92, 0.93, and 0.95 in A, B, C, and D, respectively). The averaged calculated strains were 1.69, 1.34, and 1.15 times higher than the measured strains for A, B, and C, respectively, and lower than the experimental strains for D (factor = 0.91). In conclusion, we demonstrated that specimen-specific FE analyses provide accurate estimates of peri-implant bone strains in the rat tibia loading model. Further investigations of the bone-implant interface are needed to quantify implant osseointegration.

In-vivo generation of bone via endochondral ossification by in-vitro chondrogenic priming of adult human and rat mesenchymal stem cells

LENUS (Irish Health Repository)

Farrell, Eric

2011-01-31

Abstract Background Bone grafts are required to repair large bone defects after tumour resection or large trauma. The availability of patients\\' own bone tissue that can be used for these procedures is limited. Thus far bone tissue engineering has not lead to an implant which could be used as alternative in bone replacement surgery. This is mainly due to problems of vascularisation of the implanted tissues leading to core necrosis and implant failure. Recently it was discovered that embryonic stem cells can form bone via the endochondral pathway, thereby turning in-vitro created cartilage into bone in-vivo. In this study we investigated the potential of human adult mesenchymal stem cells to form bone via the endochondral pathway. Methods MSCs were cultured for 28 days in chondrogenic, osteogenic or control medium prior to implantation. To further optimise this process we induced mineralisation in the chondrogenic constructs before implantation by changing to osteogenic medium during the last 7 days of culture. Results After 8 weeks of subcutaneous implantation in mice, bone and bone marrow formation was observed in 8 of 9 constructs cultured in chondrogenic medium. No bone was observed in any samples cultured in osteogenic medium. Switch to osteogenic medium for 7 days prevented formation of bone in-vivo. Addition of β-glycerophosphate to chondrogenic medium during the last 7 days in culture induced mineralisation of the matrix and still enabled formation of bone and marrow in both human and rat MSC cultures. To determine whether bone was formed by the host or by the implanted tissue we used an immunocompetent transgenic rat model. Thereby we found that osteoblasts in the bone were almost entirely of host origin but the osteocytes are of both host and donor origin. Conclusions The preliminary data presented in this manuscript demonstrates that chondrogenic priming of MSCs leads to bone formation in vivo using both human and rat cells. Furthermore, addition of �

Biofunctionalization of a titanium surface with a nano-sawtooth structure regulates the behavior of rat bone marrow mesenchymal stem cells

Directory of Open Access Journals (Sweden)

Zhang WJ

2012-08-01

Full Text Available Wenjie Zhang,1,2 Zihui Li,3 Yan Liu,1,2 Dongxia Ye,4 Jinhua Li,3 Lianyi Xu,1,2 Bin Wei,1 Xiuli Zhang,2 Xuanyong Liu,3,* Xinquan Jiang,1,2,* 1Department of Prosthodontics, Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, 2Oral Bioengineering Laboratory, Shanghai Research Institute of Stomatology, Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai Key Laboratory of Stomatology, 3State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 4Shanghai Research Institute of Stomatology, Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China*Joint principal authors of this workBackground: The topography of an implant surface can serve as a powerful signaling cue for attached cells and can enhance the quality of osseointegration. A series of improved implant surfaces functionalized with nanoscale structures have been fabricated using various methods. Methods: In this study, using an H2O2 process, we fabricated two size-controllable sawtooth-like nanostructures with different dimensions on a titanium surface. The effects of the two nano-sawtooth structures on rat bone marrow mesenchymal stem cells (BMMSCs were evaluated without the addition of osteoinductive chemical factors.Results: These new surface modifications did not adversely affect cell viability, and rat BMMSCs demonstrated a greater increase in proliferation ability on the surfaces of the nano-sawtooth structures than on a control plate. Furthermore, upregulated expression of osteogenic-related genes and proteins indicated that the nano-sawtooth structures promote osteoblastic differentiation of rat BMMSCs. Importantly, the large nano-sawtooth structure resulted in the greatest cell responses, including increased adhesion, proliferation

Effect of erythropoietin on the glucose transport of rat erythrocytes and bone marrow cells

International Nuclear Information System (INIS)

Ghosal, J.; Chakraborty, M.; Biswas, T.; Ganguly, C.K.; Datta, A.G.

1987-01-01

The effect of Ep on radioactive glucose and methyl-alpha-D-glucoside transport by rat erythrocytes and bone marrow cells were studied. There is initial linearity followed by saturation kinetics of [ 14 C]glucose transport by the erythrocytes of starved and starved plus Ep-treated rats at different concentrations of glucose. Starvation caused slight inhibition of glucose transport which increased markedly on Ep administration to starved rats. Normal animals failed to show any significant change in glucose transport after Ep treatment. Methyl-alpha-D-glucoside inhibited the Ep-stimulated glucose transport significantly. Ep also stimulated the transport of radioactive methyl-alpha-D-glucoside which was competitively inhibited in presence of D-glucose. Glucose transport in erythrocytes was found to be sensitive to metabolic inhibitors like azide and DNP. A sulfhydryl reagent and ouabain also inhibited the transport process. Ep stimulated glucose and methyl-alpha-D-glucoside transport in the bone marrow cells of starved rats. The sugar analog competitively inhibited the glucose transport in bone marrow cells and vice versa

The effect of therapeutic ultrasound on metallic implants: a study in rats.

Science.gov (United States)

Kocaoğlu, Barış; Cabukoglu, Cengiz; Ozeras, Nadire; Seyhan, Mustafa; Karahan, Mustafa; Yalcin, Selim

2011-11-01

To investigate whether therapeutic ultrasound (US) use over metallic implants has the potential for adverse effects as a result of greater temperature increases at the tissue-metal interface. A randomized controlled trial. A research laboratory. Sprague-Dawley rats (N=40; weight, 230-300g) were used and divided into 3 study groups. In group 1, both limbs of 10 rats were used for evaluation of temperature changes. Metal pins were placed into the femur of the left limb, and the right limbs were used as controls. A thermal sensor was placed into the medulla to record the elevation of tissue temperature during US application. In groups 2 and 3 with 15 rats in each, a midshaft femoral fracture was produced, and intramedullary fixation was performed with metal pins. Group 2 received US treatment for 5 minutes daily and continued for 27 days. Group 3 served as controls. The rats in groups 2 and 3 were killed on postoperative day 30. The specimens were evaluated by radiology, histopathology, and biomechanics. The presence of metal in bone did not cause an increased temperature rise. US application did not increase or decrease callus formation, and there was no tissue necrosis. The average removal torques of pins in groups did not show a significant difference. Internal fixation with metallic implants may not be a contraindication for therapeutic US treatment. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Alveolar wound healing after implantation with a pool of commercially available bovine bone morphogenetic proteins (BMPs): a histometric study in rats.

Science.gov (United States)

Calixto, Romeu Felipe Elias; Teófilo, Juliana Mazzonetto; Brentegani, Luiz Guilherme; Lamano-Carvalho, Teresa Lúcia

2007-01-01

The capacity of a commercially available pool of bovine bone morphogenetic proteins (BMPs) to stimulate osteogenesis in the rat alveolar healing was investigated by histometric analysis. Male rats were anesthetized and had their upper incisor extracted. A pool of purified bovine BMPs adsorbed to microgranular resorbable hydroxyapatite was agglutinated with bovine collagen and saline before implantation into the alveolar socket. The implanted and control rats (n=30 per group) were sacrificed 1 to 9 weeks postoperatively, the hemi-maxillae were decalcified, processed for paraffin embedding and semi-serial longitudinal sections were obtained and stained with hematoxylin and eosin. The volume fraction of alveolar healing components was estimated by a differential point-counting method in histologic images. The results showed that in both, control and implanted rats, the alveolar healing followed the histologic pattern usually described in the literature. Quantitative data confirmed that the BMPs mixture did not stimulate new bone formation in the alveolar socket of implanted rats. These results suggest that the pool of BMPs adsorbed to hydroxyapatite and agglutinated with bovine collagen did not warrant incorporation of the osteoinductive proteins to a slow-absorption system that would allow a BMPs release rate compatible to that of new bone formation, and thus more adequate to osteoinduction.

Study of the boron levels in serum after implantation of different ratios nano-hexagonal boron nitride-hydroxy apatite in rat femurs.

Science.gov (United States)

Atila, Alptug; Halici, Zekai; Cadirci, Elif; Karakus, Emre; Palabiyik, Saziye Sezin; Ay, Nuran; Bakan, Feray; Yilmaz, Sahin

2016-01-01

Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN-HA composites in rat femurs. All rats were (n=126) divided into five experimental groups (n=24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100 HA (Group2), femoral defect + %2.5 hBN + %97.5 HA (Group3), femoral defect + %5 hBN + %95 HA (Group4), femoral defect + %10 hBN + %90 HA (Group5), femoral defect + %100 hBN (Group6). The femoral defect was created in the distal femur (3mm drill-bit). Each implant group was divided into four different groups (n=24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN-HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN-HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers. Copyright © 2015 Elsevier B.V. All rights reserved.

Histologic Assessment of Drug-Eluting Grafts Related to Implantation Site

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Jean-Christophe Tille

2016-02-01

Full Text Available Drug-eluting vascular prostheses represent a new direction in vascular surgery to reduce early thrombosis and late intimal hyperplasia for small calibre grafts. Subcutaneous implantation in rats is a rapid and cost-effective screening model to assess the drug-elution effect and could, to some extent, be useful to forecast results for vascular prostheses. We compared biological and histological responses to scaffolds in different implantation sites. Polycaprolactone (PCL, paclitaxel-loaded PCL (PCL-PTX and dexamethasone-loaded PCL (PCL-DXM electrospun scaffolds were implanted subcutaneously and in an infrarenal abdominal aortic model in rats for up to 12 weeks. At the conclusion of the study, a histological analysis was performed. Cellular graft invasion revealed differences in the progression of cellular infiltration between PCL-PTX and PCL/PCL-DXM groups in both models. Cell infiltration increased over time in the aortic model compared to the subcutaneous model for all groups. Cell counting revealed major differences in fibroblast, macrophage and giant cell graft colonisation in all groups and models over time. Macrophages and giant cells increased in the PCL aortic model; whereas in the subcutaneous model these cell types increased only after three weeks or even decreased in the drug-eluting PCL groups. Other major findings were observed only in the aortic replacement such as extracellular matrix deposition and neo-angiogenesis. The subcutaneous implant model can be used for screening, especially when drug-eluting effects are studied. However, major histological differences were observed in cell type reaction and depth of cell penetration compared to the aortic model. Our results demonstrate that the implantation site is a critical determinant of the biological response.

Brain activation in response to visceral stimulation in rats with amygdala implants of corticosterone: an FMRI study.

Directory of Open Access Journals (Sweden)

Anthony C Johnson

2010-01-01

Full Text Available Although visceral pain of gastrointestinal (GI origin is the major complaint in patients with irritable bowel syndrome (IBS it remains poorly understood. Brain imaging studies suggest a defect in brain-gut communication in IBS with a greater activation of central arousal circuits including the amygdala. Previously, we found that stereotaxic implantation of corticosterone (CORT onto the amygdala in rats induced anxiety and colonic hypersensitivity. In the present study we used functional magnetic resonance imaging (fMRI to identify specific brain sites activated in a rat model characterized by anxiety and colonic hypersensitivity.Anesthetized male rats received micropellets (30 microg each of either CORT or cholesterol (CHOL, to serve as a control, implanted stereotaxically on the dorsal margin of each amygdala. Seven days later, rats were anesthetized and placed in the fMRI magnet (7T. A series of isobaric colorectal balloon distensions (CRD - 90s 'off', 30s 'on', 8 replicates at two pressures (40 and 60 mmHg were performed in a standard block-design. Cross correlation statistical analysis was used to determine significant differences between distended and non-distended states in CORT and CHOL-treated animals. Analysis of the imaging data demonstrated greater overall brain activation in response to CRD in rats with CORT implants compared to CHOL controls. Additionally, CORT implants produced significant positive bilateral increases in MRI signal in response to CRD in specific nuclei known as integration sites important in anxiety and pain perception.These data indicate that chronic exposure of the amygdala to elevated levels of CORT enhances overall brain activation in response to CRD, and identified other specific brain regions activated in response to mechanical distension of the colon. These results demonstrate the feasibility of performing fMRI imaging in a rodent model that supports clinical observations in IBS patients with enhanced

Failed total carpometacarpal joint prosthesis of the thumb

DEFF Research Database (Denmark)

Hansen, Torben Bæk; Homilius, Morten

2010-01-01

Total joint prosthesis in carpometacarpal joint arthritis of the thumb often fails. Loosening of the implant is often treated by resection arthroplasty, and we reviewed 10 patients, mean age 54 years (range 47-63) who were treated by resection arthroplasty after a failed total joint prosthesis. T...... in eight of 10 patients, but the mean Disabilities of the arm, shoulder, and hand (DASH) scores, self-reported pinch-grip-related function, and pain were comparable with our earlier published results with the Elektra carpometacarpal total joint prosthesis.......Total joint prosthesis in carpometacarpal joint arthritis of the thumb often fails. Loosening of the implant is often treated by resection arthroplasty, and we reviewed 10 patients, mean age 54 years (range 47-63) who were treated by resection arthroplasty after a failed total joint prosthesis....... The male:female ratio was 1:4 and the mean duration of observation 32 months (range 6-52). In three patients the revised implant was a MOJE uncemented carpometacarpal joint prosthesis and in seven patients an Elektra uncemented one. At follow-up grip strength was reduced to less than 90% of the other hand...

Hierarchical micro/nanostructured titanium with balanced actions to bacterial and mammalian cells for dental implants

Directory of Open Access Journals (Sweden)

Zhu Y

2015-10-01

immobilized Ag NPs had no apparent toxic influence on the viability, proliferation, and differentiation of rat bone marrow mesenchymal stem cells. These results demonstrated that good bactericidal activity could be obtained with very small quantities of immobilized Ag NPs, which were not detrimental to the mammalian cells involved in the osseointegration process, and promising for titanium-based dental implants with commercial SLA surfaces. Keywords: silver nanoparticles, surface modification, antibacterial effects, cytotoxicity, plasma immersion ion implantation

Comparison of metal concentrations in rat tibia tissues with various metallic implants.

Science.gov (United States)

Okazaki, Yoshimitsu; Gotoh, Emiko; Manabe, Takeshi; Kobayashi, Kihei

2004-12-01

To compare metal concentrations in tibia tissues with various metallic implants, SUS316L stainless steel, Co-Cr-Mo casting alloy, and Ti-6Al-4V and V-free Ti-15Zr-4Nb-4Ta alloys were implanted into the rat tibia for up to 48 weeks. After the implant was removed from the tibia by decalcification, the tibia tissues near the implant were lyophilized. Then the concentrations of metals in the tibia tissues by microwave acid digestion were determined by inductively coupled plasma-mass spectrometry. Fe concentrations were determined by graphite-furnace atomic absorption spectrometry. The Fe concentration in the tibia tissues with the SUS316L implant was relatively high, and it rapidly increased up to 12 weeks and then decreased thereafter. On the other hand, the Co concentration in the tibia tissues with the Co-Cr-Mo implant was lower, and it increased up to 24 weeks and slightly decreased at 48 weeks. The Ni concentration in the tibia tissues with the SUS316L implant increased up to 6 weeks and then gradually decreased thereafter. The Cr concentration tended to be higher than the Co concentration. This Cr concentration linearly increased up to 12 weeks and then decreased toward 48 weeks in the tibia tissues with the SUS316L or Co-Cr-Mo implant. Minute quantities of Ti, Al and V in the tibia tissues with the Ti-6Al-4V implant were found. The Ti concentration in the tibia tissues with the Ti-15Zr-4Nb-4Ta implant was lower than that in the tibia tissues with the Ti-6Al-4V implant. The Zr, Nb and Ta concentrations were also very low. The Ti-15Zr-4Nb-4Ta alloy with its low metal release in vivo is considered advantageous for long-term implants.

Titanium diffusion in shinbone of rats with osseointegrated implants.

Science.gov (United States)

Grenón, Miriam S; Robledo, José; Ibáñez, Juan Carlos; Sánchez, Héctor J

2016-11-01

Dental implants are composed of commercially pure Ti (which is actually an alloy of titanium, and minor or trace components such as aluminium and vanadium). When the implant is inserted, its surface undergoes a number of chemical and mechanical processes, releasing particles of titanium to the medium. The metabolism of free ions of titanium is uncertain; the uptaking processes in the body are not well known, nor their toxic dose. In addition, physical properties of newly formed bone, such as diffusivity and activation energy, are scarce and rarely studied. In this study, we analysed the diffusion of titanium in the titanium-implanted shinbones of six adult male Wistar rats by spatially resolved micro x-ray fluorescence. The measurements were carried out at the microfluorescence station of the x-ray fluorescence (XRF) beamline of the Brazilian synchrotron facility LNLS (from Portuguese 'Laboratorio Nacional de Luz Sincrotron'). For each sample, XRF spectra were taken by linear scanning in area near the new bone formed around the Ti implant. The scanning line shows a clear effect of titanium diffusion whereas calcium intensity presents a different behaviour. Moreover, a clear correlation among the different structures of bones is observed in the Ti and Ca intensities. The results obtained in these measurements may allow determining quantitatively the parameters of diffusion rates and other physical properties of new bone like diffusion coefficients. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Histological and histomorphometrical analysis of a silica matrix embedded nanocrystalline hydroxyapatite bone substitute using the subcutaneous implantation model in Wistar rats

Energy Technology Data Exchange (ETDEWEB)

Ghanaati, Shahram; Orth, Carina; Barbeck, Mike; Kirkpatrick, Charles James [Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55101 Mainz (Germany); Willershausen, Ines [Institute for Dental Material Sciences and Technology, University Medical Center of the Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 14, 55128 Mainz (Germany); Thimm, Benjamin W [Institute for Biomechanics, ETH Zuerich, Wolfgang-Pauli-Str.10, 8093 Zuerich (Switzerland); Booms, Patrick [Leeds Institute of Molecular Medicine, Section of Medicine, Surgery and Anaesthesia, University of Leeds (United Kingdom); Stuebinger, Stefan; Landes, Constantin; Sader, Robert Anton, E-mail: ghanaati@uni-mainz.d [Department for Oral, Cranio-Maxillofacial and Facial Plastic Surgery, Medical Center of the Goethe University Frankfurt, Theodor-Stein-Kai 7, 60596 Frankfurt am Main (Germany)

2010-06-01

The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascularization significantly decreased until day 90 after implantation. In this time period, the bone substitute underwent a significant degradation initiated by TRAP-positive and TRAP-negative multinucleated giant cells together with macrophages and lymphocytes. Although no specific tissue reaction could be related to the described silica degradation, the biomaterial was close to being fully degraded without a severe inflammatory response. These characteristics are advantageous for bone regeneration and remodeling processes.

Histological and histomorphometrical analysis of a silica matrix embedded nanocrystalline hydroxyapatite bone substitute using the subcutaneous implantation model in Wistar rats

International Nuclear Information System (INIS)

Ghanaati, Shahram; Orth, Carina; Barbeck, Mike; Kirkpatrick, Charles James; Willershausen, Ines; Thimm, Benjamin W; Booms, Patrick; Stuebinger, Stefan; Landes, Constantin; Sader, Robert Anton

2010-01-01

The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascularization significantly decreased until day 90 after implantation. In this time period, the bone substitute underwent a significant degradation initiated by TRAP-positive and TRAP-negative multinucleated giant cells together with macrophages and lymphocytes. Although no specific tissue reaction could be related to the described silica degradation, the biomaterial was close to being fully degraded without a severe inflammatory response. These characteristics are advantageous for bone regeneration and remodeling processes.

Repeat transcatheter aortic valve implantation using a latest generation balloon-expandable device for treatment of failing transcatheter heart valves.

Science.gov (United States)

Schaefer, Andreas; Treede, Hendrik; Seiffert, Moritz; Deuschl, Florian; Schofer, Niklas; Schneeberger, Yvonne; Blankenberg, Stefan; Reichenspurner, Hermann; Schaefer, Ulrich; Conradi, Lenard

2016-01-15

Paravalvular leakage (PVL) is a known complication of transcatheter aortic valve implantation (TAVI) and is associated with poor outcome. Besides balloon-post-dilatation, valve-in-valve (ViV) procedures can be taken into consideration to control this complication. Herein we present initial experience with use of the latest generation balloon-expandable Edwards Sapien 3® (S3) transcatheter heart valve (THV) for treatment of failing THVs. Between 01/2014 and 12/2014 three patients (two male, age: 71-80 y, log EUROScore I: 11.89 - 32.63) with failing THVs were refered to our institution for further treatment. THV approach with secondary implantation of an S3 was chosen after mutual agreement of the local interdisciplinary heart team at an interval of 533-1119 days from the index procedure. The performed procedures consisted of: S3 in Sapien XT, JenaValve and CoreValve. Successful transfemoral implantation with significant reduction of PVL was achieved in all cases. No intraprocedural complications occurred regarding placement of the S3 with a postprocedural effective orifice area (EOA) of 1.5-2.5 cm(2) and pressure gradients of max/mean 14/6-36/16 mmHg. 30-day mortality was 0%. At the latest follow-up of 90-530 days, all patients are alive and well with satisfactory THV function. Regarding VARC-2 criteria one major bleeding and one TIA was reported. In the instance of moderate or severe aortic regurgitation after TAVI, S3 ViV deployment is an excellent option to reduce residual regurgitation to none or mild. For further assertions concerning functional outcomes long-term results have to be awaited.

Scaffold-Free Tubular Tissues Created by a Bio-3D Printer Undergo Remodeling and Endothelialization when Implanted in Rat Aortae

Science.gov (United States)

Itoh, Manabu; Nakayama, Koichi; Noguchi, Ryo; Kamohara, Keiji; Furukawa, Kojirou; Uchihashi, Kazuyoshi; Toda, Shuji; Oyama, Jun-ichi; Node, Koichi; Morita, Shigeki

2015-01-01

Background Small caliber vascular prostheses are not clinically available because synthetic vascular prostheses lack endothelial cells which modulate platelet activation, leukocyte adhesion, thrombosis, and the regulation of vasomotor tone by the production of vasoactive substances. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a “Bio-3D printer”-based system. This system enables the creation of pre-designed three-dimensional structures using a computer controlled robotics system. With this system, we created a tubular structure and studied its biological features. Methods and Results Using a “Bio-3D printer,” we made scaffold-free tubular tissues (inner diameter of 1.5 mm) from a total of 500 MCSs (2.5× 104 cells per one MCS) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%), and normal human dermal fibroblasts (50%). The tubular tissues were cultured in a perfusion system and implanted into the abdominal aortas of F344 nude rats. We assessed the flow by ultrasonography and performed histological examinations on the second (n = 5) and fifth (n = 5) day after implantation. All grafts were patent and remodeling of the tubular tissues (enlargement of the lumen area and thinning of the wall) was observed. A layer of endothelial cells was confirmed five days after implantation. Conclusions The scaffold-free tubular tissues made of MCS using a Bio-3D printer underwent remodeling and endothelialization. Further studies are warranted to elucidate the underlying mechanism of endothelialization and its function, as well as the long-term results. PMID:26325298

Scaffold-Free Tubular Tissues Created by a Bio-3D Printer Undergo Remodeling and Endothelialization when Implanted in Rat Aortae.

Science.gov (United States)

Itoh, Manabu; Nakayama, Koichi; Noguchi, Ryo; Kamohara, Keiji; Furukawa, Kojirou; Uchihashi, Kazuyoshi; Toda, Shuji; Oyama, Jun-Ichi; Node, Koichi; Morita, Shigeki

2015-01-01

Small caliber vascular prostheses are not clinically available because synthetic vascular prostheses lack endothelial cells which modulate platelet activation, leukocyte adhesion, thrombosis, and the regulation of vasomotor tone by the production of vasoactive substances. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a "Bio-3D printer"-based system. This system enables the creation of pre-designed three-dimensional structures using a computer controlled robotics system. With this system, we created a tubular structure and studied its biological features. Using a "Bio-3D printer," we made scaffold-free tubular tissues (inner diameter of 1.5 mm) from a total of 500 MCSs (2.5× 104 cells per one MCS) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%), and normal human dermal fibroblasts (50%). The tubular tissues were cultured in a perfusion system and implanted into the abdominal aortas of F344 nude rats. We assessed the flow by ultrasonography and performed histological examinations on the second (n = 5) and fifth (n = 5) day after implantation. All grafts were patent and remodeling of the tubular tissues (enlargement of the lumen area and thinning of the wall) was observed. A layer of endothelial cells was confirmed five days after implantation. The scaffold-free tubular tissues made of MCS using a Bio-3D printer underwent remodeling and endothelialization. Further studies are warranted to elucidate the underlying mechanism of endothelialization and its function, as well as the long-term results.

Ion implantation induced nanotopography on titanium and bone cell adhesion

Energy Technology Data Exchange (ETDEWEB)

Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Vera, Carolina; Ayerdi-Izquierdo, Ana [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Muñoz, Roberto [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); Lorenzo, Jaione; Alvarez, Noelia [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Maeztu, Miguel Ángel de [Private Practice, P° San Francisco, 43 A-1°, 20400 Tolosa (Spain)

2014-08-15

Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm{sup 2}) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

Ion implantation induced nanotopography on titanium and bone cell adhesion

International Nuclear Information System (INIS)

Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; Maeztu, Miguel Ángel de

2014-01-01

Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm 2 ) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

Utilizing a Rat Delayed Implantation Model to Teach Integrative Endocrinology and Reproductive Biology

Science.gov (United States)

Geisert, Rodney D.; Smith, Michael F.; Schmelzle, Amanda L.; Green, Jonathan A.

2018-01-01

In this teaching laboratory, the students are directed in an exercise that involves designing and performing an experiment to determine estrogen's role in regulating delayed implantation (diapause) in female rats. To encourage active participation by the students, a discussion question is provided before the laboratory exercise in which each…

Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

International Nuclear Information System (INIS)

Eissa, Laila A.; Smith, Sylvia B.; El-sherbeny, Amira A.

2006-01-01

Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

Cell patterning on a glass surface by a mask-assisted ion implantation

Energy Technology Data Exchange (ETDEWEB)

Jung, Chan-Hee; Kim, Dong-Ki; Hwang, In-Tae; Lim, Youn-Mook; Kim, Hae-Kyoung; Nho, Young-Chang [Radiation Research Division for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Choi, Jae-Hak [Radiation Research Division for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)], E-mail: jaehakchoi@kaeri.re.kr

2009-04-15

A simple patterning method of cells on a glass has been developed by using ion implantation. The glass was implanted through a pattern mask with 150 keV Ar ions in the absence or presence of oxygen. Surface properties of the ion-implanted glass were investigated by means of X-ray photoelectron spectroscopy, contact angle measurement and cell culture test. The results showed that more hydrophilic groups were formed on the glass surface implanted in the presence of oxygen. Thus, the glass surface implanted in the presence of oxygen showed lower contact angle compared with the glass surface implanted in the absence of oxygen. The cells were strongly adhered to and proliferated on the ion-implanted regions of the glass. The cell population was found to be the highest on the glass implanted at a fluence of 1 x 10{sup 16} ions/cm{sup 2} in the presence of oxygen.

Revision of failed shoulder hemiarthroplasty to reverse total arthroplasty: analysis of 157 revision implants.

Science.gov (United States)

Merolla, Giovanni; Wagner, Eric; Sperling, John W; Paladini, Paolo; Fabbri, Elisabetta; Porcellini, Giuseppe

2018-01-01

There remains a paucity of studies examining the conversion of failed hemiarthroplasty (HA) to reverse total shoulder arthroplasty (RTSA). Therefore, the purpose of this study was to examine a large series of revision HA to RTSA. A population of 157 patients who underwent conversion of a failed HA to a revision RTSA from 2006 through 2014 were included. The mean follow-up was 49 months (range, 24-121 months). The indications for revision surgery included instability with rotator cuff insufficiency (n = 127) and glenoid wear (n = 30); instability and glenoid wear were associated in 38 cases. Eight patients with infection underwent 2-stage reimplantation. Patients experienced significant improvements in their preoperative to postoperative pain and shoulder range of motion (P surgeries, secondary to glenoid component loosening (n = 3), instability (n = 3), humeral component disassembly (n = 2), humeral stem loosening (n = 1), and infection (n = 2). Implant survivorship was 95.5% at 2 years and 93.3% at 5 years. There were 4 reoperations including axillary nerve neurolysis (n = 2), heterotopic ossification removal (n = 1), and hardware removal for rupture of the metal cerclage for an acromial fracture (n = 1). At final follow-up, there were 5 "at-risk" glenoid components. Patients experience satisfactory pain relief and recovery of reasonable shoulder function after revision RTSA from a failed HA. There was a relatively low revision rate, with glenoid loosening and instability being the most common causes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Systemic Assessment of Calcium and Phosphorus Level after Implantation of Porous Iron in Rats

Science.gov (United States)

Siallagan, S. F.; Amelia, F.; Utami, N. D.; Ulum, M. F.; Boediono, A.; Estuningsih, S.; Hermawan, H.; Noviana, D.

2017-07-01

One of important aspects in bone healing process is physiological level of calcium (Ca), and phosphorus (P) that can be altered by implantation of biodegradable porous iron. Therefore, this study aims to investigate the concentration of Ca, P and Ca/P ratio in the peripheral blood during the implantation period up to 4 months. Forty adult male Sprague Dawley rats were used and divided into 3 groups receiving different pore size of iron implants (pore size 450, 580, 800μm) and one group of sham. The implants (5x2x0.5mm) were inserted into flat bone defects at latero-medial of femoral bone. Blood sample was taken from ventral tail artery before and after 4 month of implantation. Calcium and P concentrations in the blood were determined by BA-88A Semi-Auto Chemistry Analyzer. Results showed that concentration of Ca and P are slightly higher after implantation than before implantation, except for the 450μm group. The Ca/P ratio before and after implantation was increased in the sham group, and decreased in the 450 and 800μm groups. Concentration of Ca, P and Ca/P ratio insignificantly change between before and 4 months after surgery in some groups.

Failed anti-tachycardia pacing can be used to differentiate atrial arrhythmias from ventricular tachycardia in implantable cardioverter-defibrillators.

Science.gov (United States)

Michael, Kevin A; Enriquez, Andres; Baranchuk, Adrian; Haley, Charlotte; Caldwell, Jane; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P

2015-01-01

Atrial fibrillation/tachycardia (AF/AT) may result in inappropriate therapies in implantable cardioverter-defibrillators (ICDs). The post-pacing interval (PPI) and tachycardia cycle length difference (PPI - TCL) has been previously demonstrated to indicate the proximity of the pacing site to a tachycardia origin. We postulated that the PPI and PPI - TCL would be greater in AT/AF vs. ventricular tachycardia (VT) after episodes of failed anti-tachycardia pacing (ATP). This was a single-centre, retrospective study evaluating consecutive patients implanted with dual (DR)/biventricular (BIV) ICDs. Stored electrograms were used to determine whether the ATP captured the arrhythmia and the arrhythmia did not present with primary or secondary termination. Measurements were done using manual calipers. A total of 155 patients were included. There were 79 BIV and 76 DR devices. In total, 39 episodes were identified in 20 patients over a 23-month follow-up period. A total of 76 sequences of ATP (burst/ramp) were delivered, 28 (37%) of them inappropriate. Fifty-one events (18 AT/AF and 33 VT) were compared. The mean PPI was 693 ± 96 vs. 512 ± 88 ms (P failed ATP differs significantly between AF/AT and VT and are therefore useful indices to discriminate between supraventricular tachycardia and VT in ICDs. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Two-generation reproductive toxicity study of implanted depleted uranium (DU) in CD rats.

Science.gov (United States)

Arfsten, D P; Still, K R; Wilfong, E R; Johnson, E W; McInturf, S M; Eggers, J S; Schaeffer, D J; Bekkedal, M Y-V

2009-01-01

Depleted uranium (DU) munitions and armor plating have been used in several conflicts over the last 17 yr, including the Persian Gulf War and the Iraq War. Because of its effectiveness and availability, DU will continue to be used in military applications into the foreseeable future. There is much controversy over the use of DU in weapons and equipment because of its potential radiological and toxic hazards, and there is concern over the chronic adverse health effects of embedded DU shrapnel in war veterans and bystanders. This study evaluated the effects of long-term implantation of DU on the reproductive success of F0 generation adults and development and survival of subsequent F1 and F2 generations in a two-generation reproductive toxicity study. F0 generation Sprague-Dawley rats, 8 wk of age, were surgically implanted with 0, 4, 8, 12, or 20 DU pellets (1 x 2 mm). Inert implant control animals were implanted with 12 or 20 tantallum (Ta) pellets. The F0 generation was then mated at 120 d post DU implantation. In the F0 generation, when measured on postimplantation d 27 and 117, uranium was present in the urine of DU-implanted animals in a dose-dependent manner. F0 reproductive success was similar across treatment groups and the maternal retrieval test revealed no changes in maternal behavior. DU implantation exerted no effect on the survival, health, or well-being of the F0 generation. Necropsy results of F0 animals were negative with the exception of a marked inflammatory response surrounding the implanted DU pellets. For the F1 generation, measures of F1 development through postnatal day (PND) 20 were unremarkable and no gross abnormalities were observed in F1 offspring. No uranium was detected in whole-body homogenates of PND 4 or PND 20 pups. Necropsy findings of F1 PND 20 pups were negative and no instances of ribcage malformation were observed in F1 PND 20 pups. Body weight and body weight gain of F1 rats through PND 120 were similar across treatment

Bone reactions at implants subjected to experimental peri-implantitis and static load. A study in the dog

DEFF Research Database (Denmark)

Gotfredsen, K; Berglundh, T; Lindhe, J

2002-01-01

during a 12-week interval, the screws were reactivated. Thus, the model included 3 different experimental sites of each surface group: group M+L (mucositis+load); group P (peri-implantitis); group P+L (peri-implantitis+load). Fluorochrome labels were injected and standardized radiographs obtained....... The animals were sacrificed and block biopsies of all implant sites dissected and prepared for histological analysis. RESULTS: It was demonstrated that the lateral static load failed to induce peri-implant bone loss at implants with mucositis and failed to enhance the bone loss at implants with experimental...... peri-implantitis. The proportion of bone labels and the bone density in the interface zone were significantly higher in group P+L than in group P. CONCLUSION: It is suggested that a lateral static load with controlled forces may not be detrimental to implants exhibiting mucositis or peri-implantitis....

Alkaline biodegradable implants for osteoporotic bone defects--importance of microenvironment pH.

Science.gov (United States)

Liu, W; Wang, T; Yang, C; Darvell, B W; Wu, J; Lin, K; Chang, J; Pan, H; Lu, W W

2016-01-01

Change of microenvironment pH by biodegradable implants may ameliorate unbalanced osteoporotic bone remodeling. The present work demonstrated that a weak alkaline condition stimulated osteoblasts differentiation while suppressed osteoclast generation. In vivo, implants with an alkaline microenvironment pH (monitored by a pH microelectrode) exhibited a promising healing effect for the repair of osteoporotic bone defects. Under osteoporotic conditions, the response of the bone microenvironment to an endosseous implant is significantly impaired, and this substantially increases the risk of fracture, non-union and aseptic implant loosening. Acid-base equilibrium is an important factor influencing bone cell behaviour. The present purpose was to study the effect of a series of alkaline biodegradable implant materials on regeneration of osteoporotic bone defect, monitoring the microenvironment pH (μe-pH) over time. The proliferation and differentiation potential of osteoporotic rat bone marrow stromal cells and RAW 264.7 cells were examined under various pH conditions. Ovariectomized rat bone defects were filled with specific biodegradable materials, and μe-pH was measured by pH microelectrode. New osteoid and tartrate-resistant acid phosphatase-positive osteoclast-like cells were examined by Goldner's trichrome and TRAP staining, respectively. The intermediate layer between implants and new bone were studied using energy-dispersive X-ray spectroscopy (EDX) linear scanning. In vitro, weak alkaline conditions stimulated osteoporotic rat bone marrow stromal cells (oBMSC) differentiation, while inhibiting the formation of osteoclasts. In vivo, μe-pH differs from that of the homogeneous peripheral blood and exhibits variations over time particular to each material. Higher initial μe-pH was associated with more new bone formation, late response of TRAP-positive osteoclast-like cells and the development of an intermediate 'apatitic' layer in vivo. EDX suggested that

Ectopic bone formation in nude rats using human osteoblasts seeded poly(3)hydroxybutyrate embroidery and hydroxyapatite-collagen tapes constructs.

Science.gov (United States)

Mai, Ronald; Hagedorn, Manolo Gunnar; Gelinsky, Michael; Werner, Carsten; Turhani, Dritan; Späth, Heike; Gedrange, Tomas; Lauer, Günter

2006-09-01

The aim of this study was to evaluate the ectopic bone formation using tissue engineered cell-seeded constructs with two different scaffolds and primary human maxillary osteoblasts in nude rats over an implantation period of up to 96 days. Collagen I-coated Poly(3)hydroxybutyrate (PHB) embroidery and hydroxyapatite (HAP) collagen tapes were seeded with primary human maxillary osteoblasts (hOB) and implanted into athymic rnu/run rats. A total of 72 implants were placed into the back muscles of 18 rats. 24, 48 and 96 days after implantation, histological and histomorphometric analyses were made. The osteoblastic character of the cells was confirmed by immunocytochemistry and RT-PCR for osteocalcin. Histological analysis demonstrated that all cell-seeded constructs induced ectopic bone formation after 24, 48 and 96 days of implantation. There was more mineralized tissue in PHB constructs than in HAP-collagen tapes (at day 24; p embroidery or HAP-collagen tapes can induce ectopic bone formation. However, the amount of bone formed decreased with increasing length of implantation.

Energy harvesting by implantable abiotically catalyzed glucose fuel cells

Science.gov (United States)

Kerzenmacher, S.; Ducrée, J.; Zengerle, R.; von Stetten, F.

Implantable glucose fuel cells are a promising approach to realize an autonomous energy supply for medical implants that solely relies on the electrochemical reaction of oxygen and glucose. Key advantage over conventional batteries is the abundant availability of both reactants in body fluids, rendering the need for regular replacement or external recharging mechanisms obsolete. Implantable glucose fuel cells, based on abiotic catalysts such as noble metals and activated carbon, have already been developed as power supply for cardiac pacemakers in the late-1960s. Whereas, in vitro and preliminary in vivo studies demonstrated their long-term stability, the performance of these fuel cells is limited to the μW-range. Consequently, no further developments have been reported since high-capacity lithium iodine batteries for cardiac pacemakers became available in the mid-1970s. In recent years research has been focused on enzymatically catalyzed glucose fuel cells. They offer higher power densities than their abiotically catalyzed counterparts, but the limited enzyme stability impedes long-term application. In this context, the trend towards increasingly energy-efficient low power MEMS (micro-electro-mechanical systems) implants has revived the interest in abiotic catalysts as a long-term stable alternative. This review covers the state-of-the-art in implantable abiotically catalyzed glucose fuel cells and their development since the 1960s. Different embodiment concepts are presented and the historical achievements of academic and industrial research groups are critically reviewed. Special regard is given to the applicability of the concept as sustainable micro-power generator for implantable devices.

Effect of calcium phosphate coating crystallinity and implant surface roughness on differentiation of rat bone marrow cells.

NARCIS (Netherlands)

Brugge, P.J. ter; Wolke, J.G.C.; Jansen, J.A.

2002-01-01

In this study, we examined the effect of calcium phosphate (Ca-P) coating crystallinity and of surface roughness on growth and differentiation of osteogenic cells. Grit-blasted titanium substrates were provided with Ca-P coatings of different crystallinities. Rat bone marrow (RBM) cells were

Induced hemocompatibility and bone formation as biological scaffold for cell therapy implant

Directory of Open Access Journals (Sweden)

Keng-Liang Ou

2016-06-01

Full Text Available Although stem cells can become almost any type of specialized cell in the human body and may have the potential to generate replacement cells for tissues and organs, the transplantation of these cells are hindered by immune rejection and teratoma formation. However, scientists have found a promising solution for these problems-they have discovered the ability to isolate stem cells from a patient’s umbilical cord blood or bone marrow. Even more recently, small stem cells, such as spore-like stem cells, Blastomere-Like Stem Cells (BLSCs, and Very-Small Embryonic-Like stem cells (VSELs isolated directly from the peripheral blood have beeninvestigated as a novel approach to stem cell therapy as they can be isolated directly from the peripheral blood. A newly-discovered population of multipotent stem cells in this class has been dubbed StemBios (SB cells. The potential therapeutic uses of such stem cells have been explored in many ways, one of which includes dental remodeling and construction. Using adult stem cells, scientists have engineered and cultivated teeth in mice that may one day be used for human implantation.It follows that such regeneration may be possible, to a certain degree, in human patients as well. This idea leads to the present study on the effect of SB cell therapy on early osseointegrationof dental implants. Titanium (Ti dental implants have been proven to be a reliable and predictable treatment for restoration of edentulous regions. The osseointegration process can be described in two stages: primary stability (mechanical stability and secondary stability (biological stability. The mechanical stabilization of the implant reflects the interaction between the bone density and the features of the implant designs and can be determined after implant insertion. Alternatively,the biological stabilization of the implant is a physiologic healing process. It is couple to the biological interaction between the external surface of the

Neuron attachment properties of carbon negative-ion implanted bioabsorbable polymer of poly-lactic acid

International Nuclear Information System (INIS)

Tsuji, Hiroshi; Sasaki, Hitoshi; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

2002-01-01

Modification of a bioabsorbable polymer of poly-lactic acid (PLA) by negative carbon ion implantation was investigated with resect to radiation effects on surface physical properties and nerve-cell attachment properties. Carbon negative ions were implanted to PLA at energy of 5-30 keV with a dose of 10 14 -10 16 ions/cm 2 . Most C-implanted PLA samples showed contact angles near 80 deg. and almost same as that of unimplanted PLA, although a few samples at 5 keV and less 3x10 14 ions/cm 2 had contact angles larger than 90 deg. The attachment properties of nerve cells of PC-12h (rat adrenal phechromocytoma) in vitro were studied. PC-12h cells attached on the unimplanted region in C-implanted PLA samples at 5 and 10 keV. On the contrary, the nerve cells attached on only implanted region for the C-implanted PLA sample at 30 keV and 1x10 15 ions/cm 2

Cell-laden hydrogel/titanium microhybrids: Site-specific cell delivery to metallic implants for improved integration.

Science.gov (United States)

Koenig, Geraldine; Ozcelik, Hayriye; Haesler, Lisa; Cihova, Martina; Ciftci, Sait; Dupret-Bories, Agnes; Debry, Christian; Stelzle, Martin; Lavalle, Philippe; Vrana, Nihal Engin

2016-03-01

Porous titanium implants are widely used in dental, orthopaedic and otorhinolaryngology fields to improve implant integration to host tissue. A possible step further to improve the integration with the host is the incorporation of autologous cells in porous titanium structures via cell-laden hydrogels. Fast gelling hydrogels have advantageous properties for in situ applications such as localisation of specific cells and growth factors at a target area without dispersion. The ability to control the cell types in different regions of an implant is important in applications where the target tissue (i) has structural heterogeneity (multiple cell types with a defined spatial configuration with respect to each other); (ii) has physical property gradients essential for its function (such as in the case of osteochondral tissue transition). Due to their near immediate gelation, such gels can also be used for site-specific modification of porous titanium structures, particularly for implants which would face different tissues at different locations. Herein, we describe a step by step design of a model system: the model cell-laden gel-containing porous titanium implants in the form of titanium microbead/hydrogel (maleimide-dextran or maleimide-PVA based) microhybrids. These systems enable the determination of the effect of titanium presence on gel properties and encapsulated cell behaviour as a miniaturized version of full-scale implants, providing a system compatible with conventional analysis methods. We used a fibroblast/vascular endothelial cell co-cultures as our model system and by utilising single microbeads we have quantified the effect of gel microenvironment (degradability, presence of RGD peptides within gel formulation) on cell behaviour and the effect of the titanium presence on cell behaviour and gel formation. Titanium presence slightly changed gel properties without hindering gel formation or affecting cell viability. Cells showed a preference to move towards

Breast implant capsule-associated squamous cell carcinoma: a report of 2 cases.

Science.gov (United States)

Olsen, Daniel L; Keeney, Gary L; Chen, Beiyun; Visscher, Daniel W; Carter, Jodi M

2017-09-01

The use of prosthetic implants for breast augmentation has become commonplace. Although implants do not increase the risk of conventional mammary carcinoma, they are rarely associated with anaplastic large cell lymphoma. We report 2 cases of breast implant capsule-associated squamous cell carcinoma with poor clinical outcomes. Both patients (56-year-old woman and 81-year-old woman) had long-standing implants (>25 years) and presented with acute unilateral breast enlargement. In both cases, squamous cell carcinoma arose in (focally dysplastic) squamous epithelium-lined breast implant capsules and widely invaded surrounding breast parenchyma or chest wall. Neither patient had evidence of a primary mammary carcinoma or squamous cell carcinoma at any other anatomic site. Within 1 year, one patient developed extensive, treatment-refractory, locoregional soft tissue metastasis, and the second patient developed hepatic and soft tissue metastases and died of disease. There are 2 prior reported cases of implant-associated squamous cell carcinoma in the plastic surgery literature; one provides no pathologic staging or outcome information, and the second case was a capsule-confined squamous cell carcinoma. Together, all 4 cases share notable commonalities: the patients had long-standing breast implants and presented with acute unilateral breast pain and enlargement secondary to tumors arising on the posterior aspect of squamous epithelialized implant capsules. Because of both its rarity and its unusual clinical presentation, implant capsule-associated squamous cell carcinoma may be underrecognized. The aggressive behavior of the tumors in this series underscores the importance of excluding malignancy in patients with long-standing breast implants who present with acute unilateral breast pain and enlargement. Copyright © 2017 Elsevier Inc. All rights reserved.

Peri-implant and Paracrestal Inflammatory Biomarkers at Failing Versus Surviving Implant Sites in a Beagle Dog Study.

Science.gov (United States)

Montero, Javier; Aragón, Fernando; Blanco, Leticia A; Guadilla, Yasmina; García-Cenador, Begona; López-Valverde, Antonio

This study sought to quantify three biochemical mediators of inflammation (tumor necrosis factor alpha [TNF-α], superoxide anion [SOA], and myeloperoxidase [MPO]) by analyzing crestal (peri-implants) and paracrestal gingival biopsy samples obtained from an experimental study on beagle dogs treated with implants inserted immediately into fresh sockets with circumferential defects. In 10 beagle dogs, 4 roughened titanium implants (3.8 mm wide × 8 mm high) were placed in the distal sockets of the third and fourth premolars, where a circumferential defect (5 mm wide and 5 mm deep) had been previously created by trephination. After varying follow-up periods, ranging from 80 to 190 days, the dogs were explored clinically to assess implant survival, peri-implant pocket depth, and implant stability. The levels of three biochemical mediators of inflammation (MPO, TNF-α, and SOA) were investigated using the crestal and paracrestal gingival biopsy samples with ELISA tests. It was found that 37.5% of the implants were either absent or mobile. Higher levels of the inflammatory mediators were found in the crestal samples than in the paracrestal samples. The final implant stability values were significantly correlated with the final probing depth (r = -0.83, P < .01), but neither of the clinical measures were significantly correlated with any biochemical marker. The risk of implant failure was significantly proportional to the level of MPO (odds ratio: 1.1) and TNF-α (odds ratio: 1.1) in both the crestal and paracrestal regions. All the inflammatory mediators studied were higher in the crestal areas than in the paracrestal regions, but only the values of MPO and TNF-α were significant predictors of implant failure.

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

OpenAIRE

Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

2014-01-01

All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older peop...

Implanted, inductively-coupled, radiofrequency coils fabricated on flexible polymeric material: Application to in vivo rat brain MRI at 7 T

International Nuclear Information System (INIS)

Ginefri, J.C.; Poirier-Quinot, M.; Darrasse, L.; Rubin, A.; Tatoulian, M.; Woytasik, M.; Boumezbeur, F.; Djemai, B.; Lethimonnier, F.

2012-01-01

Combined with high-field MRI scanners, small implanted coils allow for high resolution imaging with locally improved SNR, as compared to external coils. Small flexible implantable coils dedicated to in vivo MRI of the rat brain at 7 T were developed. Based on the Multi-turn Transmission Line Resonator design, they were fabricated with a Teflon substrate using copper micro-molding process and a specific metal-polymer adhesion treatment. The implanted coils were made biocompatible by Polydimethylsiloxane (PDMS) encapsulation. The use of low loss tangent material achieves low dielectric losses within the substrate and the use of the PDMS layer reduces the parasitic coupling with the surrounding media. An implanted coil was implemented in a 7 T MRI system using inductive coupling and a dedicated external pick-up coil for signal transmission. In vivo images of the rat brain acquired with in plane resolution of (150 μm) 2 thanks to the implanted coil revealed high SNR near the coil, allowing for the visualization of fine cerebral structures. (authors)

Histological study on acute inflammatory reaction to polyurethane-coated silicone implants in rats Estudo histológico da reação inflamatória aguda ao implante de silicone revestido com poliuretano em ratos

OpenAIRE

Paulo Roberto da Silva Mendes; Jorge Bins-Ely; Eduardo Arnaut dos Santos Lima; Zulmar Antonio Accioli de Vasconcellos; Armando José d'Acampora; Rodrigo d' Eça Neves

2008-01-01

PURPOSE: Evaluating histologically the silicone peri-implant coated by polyurethane inflammation associated to the use of anti-microbial and bacterial contamination. METHODS: It was used 35 Wistar rats. The animals were divided in seven groups: I - Control; II - implant cavity contamination with10 bacteria/ml; III - implant cavity contamination with 10 bacteria/ml; IV - implant cavity contamination with 10 bacteria/ml; V - identical contamination to group II and implant immersions in anti-mic...

Mechanical verification of soft-tissue attachment on bioactive glasses and titanium implants.

Science.gov (United States)

Zhao, Desheng; Moritz, Niko; Vedel, Erik; Hupa, Leena; Aro, Hannu T

2008-07-01

Soft-tissue attachment is a desired feature of many clinical biomaterials. The aim of the current study was to design a suitable experimental method for tensile testing of implant incorporation with soft-tissues. Conical implants were made of three compositions of bioactive glass (SiO(2)-P(2)O(5)-B(2)O(3)-Na(2)O-K(2)O-CaO-MgO) or titanium fiber mesh (porosity 84.7%). The implants were surgically inserted into the dorsal subcutaneous soft-tissue or back muscles in the rat. Soft-tissue attachment was evaluated by pull-out testing using a custom-made jig 8 weeks after implantation. Titanium fiber mesh implants had developed a relatively high pull-out force in subcutaneous tissue (12.33+/-5.29 N, mean+/-SD) and also measurable attachment with muscle tissue (2.46+/-1.33 N). The bioactive glass implants failed to show mechanically relevant soft-tissue bonding. The experimental set-up of mechanical testing seems to be feasible for verification studies of soft-tissue attachment. The inexpensive small animal model is beneficial for large-scale in vivo screening of new biomaterials.

Analysis of metallic traces from the biodegradation of endomedullary AZ31 alloy temporary implants in rat organs after long implantation times.

Science.gov (United States)

Bodelón, O G; Iglesias, C; Garrido, J; Clemente, C; Garcia-Alonso, M C; Escudero, M L

2015-08-04

AZ31 alloy has been tested as a biodegradable material in the form of endomedullary implants in female Wistar rat femurs. In order to evaluate the accumulation of potentially toxic elements from the biodegradation of the implant, magnesium (Mg), aluminium (Al), zinc (Zn), manganese (Mn) and fluorine (F) levels have been measured in different organs such as kidneys, liver, lungs, spleen and brain. Several factors that may influence accumulation have been taken into account: how long the implant has been in place, whether or not the bone is fractured, and the presence of an MgF2 protective coating on the implant. The main conclusions and the clinical relevance of the study have been that AZ31 endomedullary implants have a degradation rate of about 60% after 13 months, which is fully compatible with fracture consolidation. Neither bone fracture nor an MgF2 coating seems to influence the accumulation of trace elements in the studied organs. Aluminium is the only alloying element in this study that requires special attention. The increase in Al recovered from the sampled organs represents 3.95% of the amount contained in the AZ31 implant. Al accumulates in a statistically significant way in all the organs except the brain. All of this suggests that in long-term tests AZ31 may be a suitable material for osteosynthesis.

Remote ischemic preconditioning fails to reduce infarct size in the Zucker fatty rat model of type-2 diabetes: role of defective humoral communication.

Science.gov (United States)

Wider, Joseph; Undyala, Vishnu V R; Whittaker, Peter; Woods, James; Chen, Xuequn; Przyklenk, Karin

2018-03-09

Remote ischemic preconditioning (RIPC), the phenomenon whereby brief ischemic episodes in distant tissues or organs render the heart resistant to infarction, has been exhaustively demonstrated in preclinical models. Moreover, emerging evidence suggests that exosomes play a requisite role in conveying the cardioprotective signal from remote tissue to the myocardium. However, in cohorts displaying clinically common comorbidities-in particular, type-2 diabetes-the infarct-sparing effect of RIPC may be confounded for as-yet unknown reasons. To investigate this issue, we used an integrated in vivo and in vitro approach to establish whether: (1) the efficacy of RIPC is maintained in the Zucker fatty rat model of type-2 diabetes, (2) the humoral transfer of cardioprotective triggers initiated by RIPC are transported via exosomes, and (3) diabetes is associated with alterations in exosome-mediated communication. We report that a standard RIPC stimulus (four 5-min episodes of hindlimb ischemia) reduced infarct size in normoglycemic Zucker lean rats, but failed to confer protection in diabetic Zucker fatty animals. Moreover, we provide novel evidence, via transfer of serum and serum fractions obtained following RIPC and applied to HL-1 cardiomyocytes subjected to hypoxia-reoxygenation, that diabetes was accompanied by impaired humoral communication of cardioprotective signals. Specifically, our data revealed that serum and exosome-rich serum fractions collected from normoglycemic rats attenuated hypoxia-reoxygenation-induced HL-1 cell death, while, in contrast, exosome-rich samples from Zucker fatty rats did not evoke protection in the HL-1 cell model. Finally, and unexpectedly, we found that exosome-depleted serum from Zucker fatty rats was cytotoxic and exacerbated hypoxia-reoxygenation-induced cardiomyocyte death.

Investigation of Implantable Multi-Channel Electrode Array in Rat Cerebral Cortex Used for Recording

Science.gov (United States)

Taniguchi, Noriyuki; Fukayama, Osamu; Suzuki, Takafumi; Mabuchi, Kunihiko

There have recently been many studies concerning the control of robot movements using neural signals recorded from the brain (usually called the Brain-Machine interface (BMI)). We fabricated implantable multi-electrode arrays to obtain neural signals from the rat cerebral cortex. As any multi-electrode array should have electrode alignment that minimizes invasion, it is necessary to customize the recording site. We designed three types of 22-channel multi-electrode arrays, i.e., 1) wide, 2) three-layered, and 3) separate. The first extensively covers the cerebral cortex. The second has a length of 2 mm, which can cover the area of the primary motor cortex. The third array has a separate structure, which corresponds to the position of the forelimb and hindlimb areas of the primary motor cortex. These arrays were implanted into the cerebral cortex of a rat. We estimated the walking speed from neural signals using our fabricated three-layered array to investigate its feasibility for BMI research. The neural signal of the rat and its walking speed were simultaneously recorded. The results revealed that evaluation using either the anterior electrode group or posterior group provided accurate estimates. However, two electrode groups around the center yielded poor estimates although it was possible to record neural signals.

Cell adhesion of F{sup +} ion implantation of intraocular lens

Energy Technology Data Exchange (ETDEWEB)

Li, D.J. E-mail: dejunli@hotmail.com; Cui, F.Z.; Gu, H.Q

1999-04-01

The cell adhesion of ion implanted polymethylmethacrylate (PMMA) intraocular lens was studied using cultured cells in vitro. F{sup +} ion implantation was performed at the energies of 40, 60, 80, 100 keV with the fluences ranging from 5x10{sup 13} to 1x10{sup 15} ions/cm{sup 2} at room temperature. The cell adhesion tests gave interesting results that the number of the neutral granulocytes and the macrophages adhering on surface were reduced significantly after ion implantation. The optimal fluence was about 4x10{sup 14} ions/cm{sup 2}. The hydrophobicity imparted to the lens surface was also enhanced. The results of X-ray photoelectron spectroscopy analysis indicated that ion implantation resulted in the cleavage of some pendant groups, the oxidation of the surface, and the formation of some new chemical bonds, which was probably the main reason for the cell adhesion change.

Effect of oxygen deprivation on metabolism of arachidonic acid by cultures of rat heart cells

International Nuclear Information System (INIS)

Freyss-Beguin, M.; Millanvoye-van Brussel, E.; Duval, D.

1989-01-01

To investigate the mechanisms responsible for the impairment of phospholipid metabolism observed in ischemic cells, we have studied the effect of conditions simulating ischemia on the metabolism of arachidonic acid (AA) by muscle (M-) and nonmuscle (F-) cells isolated from newborn rat hearts and cultured separately. In muscle cells, oxygen deprivation induces a significant stimulation of the release of [ 14 C]AA from prelabeled cells associated with a preferential redistribution of [ 14 C]AA into cell triglycerides but not formation of radioactive prostaglandins. Moreover, the fatty acid content of phospholipids, as measured by capillary gas chromatography, appears markedly reduced in ischemic myocardial cells. This fact may be related to phospholipase stimulation during ischemia as suggested by the antagonistic effect of mepacrine or p-bromophenacyl bromide. In contrast, oxygen deprivation failed to induce any significant alteration of AA metabolism in fibroblast-like heart cells. Our results indicate that these cultures of newborn rat heart cells, which exhibit many of the features observed in intact organ during ischemia, may represent a useful experimental model to investigate the pharmacological control of the membrane phospholipid turnover

Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

KAUST Repository

Jain, Harsh Vardhan

2012-07-01

Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O(2)) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O(2)-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O(2) pressure (pO(2)) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO(2) to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases.

Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

KAUST Repository

Jain, Harsh Vardhan; Moldovan, Nicanor I.; Byrne, Helen M.

2012-01-01

Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O(2)) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O(2)-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O(2) pressure (pO(2)) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO(2) to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases.

Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

Science.gov (United States)

Moldovan, Nicanor I.; Byrne, Helen M.

2012-01-01

Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O2) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O2-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O2 pressure (pO2) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO2 to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases. PMID:22224628

Transition from failing dentition to full-arch fixed implant-supported prosthesis with a staged approach using removable partial dentures: a case series.

Science.gov (United States)

Cortes, Arthur Rodriguez Gonzalez; Cortes, Djalma Nogueira; No-Cortes, Juliana; Arita, Emiko Saito

2014-06-01

The present retrospective case series is aimed at evaluating a staged approach using a removable partial denture (RPD) as an interim prosthesis in treatment to correct a failing dentition until such time as a full-arch fixed implant-supported prosthesis may be inserted. Eight patients, who had undergone maxillary full-arch rehabilitation with dental implants due to poor prognosis of their dentitions, were analyzed. All treatment included initial periodontal therapy and a strategic order of extraction of hopeless teeth. An RPD supported by selected teeth rehabilitated the compromised arch during implant osseointegration. These remaining teeth were extracted prior to definitive prosthesis delivery. Advantages and drawbacks of this technique were also recorded for the cases presented. Among the advantages provided by the staged approach are simplicity of fabrication, low cost, and ease of insertion. Additionally, RPD tooth support prevented contact between the interim prosthesis and healing abutments, promoting implant osseointegration. The main drawbacks were interference with speech and limited esthetic results. Implant survival rate was 100% within a follow-up of at least 1 year. The use of RPDs as interim prostheses allowed for the accomplishment of the analyzed rehabilitation treatments. It is a simple treatment alternative for patients with a low smile line. © 2013 by the American College of Prosthodontists.

Ultrastructural study of tissues surrounding replanted teeth and dental implants.

Science.gov (United States)

Shioya, Kazuhiro; Sawada, Takashi; Miake, Yasuo; Inoue, Sadayuki; Yanagisawa, Takaaki

2009-03-01

The aim of this study was to describe the ultrastructure of the dentogingival border at replanted teeth and implants. Wistar rats (8 weeks old) were divided into groups for replantation and implantation experiments. In the former, the upper right first molars were extracted and then immediately replanted. In the latter, pure titanium implants were used. All tissues were fixed, demineralized and embedded in epoxy resin for ultrastructural observations. One week after replantation, the junctional epithelium was lost, and the oral sulcular epithelium covered the enamel surface. The amount of the epithelium increased in 2 weeks, and resembled the junctional epithelium, and the internal basal lamina and hemidesmosomes were formed in 4 weeks. One week after implantation, peri-implant epithelium was formed, and in 2 and 4 weeks, this epithelium with aggregated connective tissue cells were observed. In 8 weeks, the peri-implant epithelium receded, and aligned special cells with surrounding elongated fibroblasts and bundles of collagen fibers appeared to seal the implant interface. In replantation of the tooth, the internal basal lamina remained at the surface of the enamel of the replanted tooth, which is likely to be related to regeneration of the junctional epithelium and the attachment apparatus at the epithelium-tooth interface. Following implantation, a layer of cells with characteristics of connective tissue cells, but no junctional epithelium and attachment apparatus, was formed to seal the site of the implant.

Quinacrine enhances carmustine therapy of experimental rat glioma.

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Reyes, S; Herrera, L A; Ostrosky, P; Sotelo, J

2001-10-01

The high rate of mutagenesis in malignant cells has been considered to be a primary factor in the appearance of chemotherapy-resistant cell clones in glioblastomas. Quinacrine binds strongly to deoxyribonucleic acid, preventing mutagenesis. We investigated whether quinacrine could improve carmustine therapy in C6 cell cultures and in C6 malignant gliomas implanted subcutaneously into Wistar rats. A potential chemopreventive effect of quinacrine on acquired resistance to carmustine therapy was studied in vitro and in vivo. Deoxyribonucleic acid damage was measured in cultured C6 cells by using the micronucleus test. Wistar rats with subcutaneously implanted C6 gliomas were treated with carmustine, quinacrine, or carmustine plus quinacrine, using pharmacological schemes similar to those used for human patients. The addition of quinacrine to cultured C6 cells did not modify carmustine-induced cytotoxicity; however, the deoxyribonucleic acid damage in surviving cells was minor, as indicated by the frequency of micronucleated cells. The surviving cells continued to be susceptible to a second exposure to carmustine, in contrast to non-quinacrine-treated control cells, which developed resistance to carmustine in a subsequent exposure (P < 0.05). The rate of tumor remission was higher for glioma-bearing rats treated with quinacrine plus carmustine, compared with rats treated with carmustine alone (P < 0.01). The addition of quinacrine to carmustine therapy increases the antineoplastic effect of the carmustine therapy. Our results suggest that chemical inhibition of mutagenesis in malignant glial cells during chemotherapy prevents the appearance of resistant clones.

Repair effect of transplantation of bone marrow mesenchymal stem cells on liver injury in severe burned rats and its mechanism

International Nuclear Information System (INIS)

Chen Hao; Zhou Yubo; Zhang Ying; Qin Yonggang; Guo Li; Yin Fei; Meng Chunyang; Yang Xiaoyu

2014-01-01

model group, and the apoptotic rate of liver cells in cell therapy group was significantly Lower than that in model group (P<0.05). CM-Dil labeled BMSCs were found in liver tissue of the rats in cell therapy group under confocal microscope. Conclusion: BMSCs can implant into the damaged liver tissue after transplantation, and BMSCs have an obvious repair effect on liver injury caused by burning, and the possible mechanism may be associated with the inhibiting of apoptosis. (authors)

Nanostructured implant surface effect on osteoblast gene expression and bone-to-implant contact in vivo

Energy Technology Data Exchange (ETDEWEB)

Mendonca, Gustavo, E-mail: gustavo_mendonca@dentistry.unc.edu [Universidade Catolica de Brasilia, Pos-Graduacao em Ciencias Genomicas e Biotecnologia, SGAN Quadra 916, Modulo B, Av. W5 Norte 70.790-160-Asa Norte Brasilia/DF (Brazil); Bone Biology and Implant Therapy Laboratory, Department of Prosthodontics, University of North Carolina at Chapel Hill, 404 Brauer Hall, CB 7450, Chapel Hill, NC 27511 (United States); Universidade Catolica de Brasilia, Curso de Odontologia, Taguatinga/DF (Brazil); Baccelli Silveira Mendonca, Daniela [Universidade Catolica de Brasilia, Pos-Graduacao em Ciencias Genomicas e Biotecnologia, SGAN Quadra 916, Modulo B, Av. W5 Norte 70.790-160-Asa Norte Brasilia/DF (Brazil) and Bone Biology and Implant Therapy Laboratory, Department of Prosthodontics, University of North Carolina at Chapel Hill, 404 Brauer Hall, CB 7450, Chapel Hill, NC 27511 (United States); Pagotto Simoes, Luis Gustavo; Araujo, Andre Luis; Leite, Edson Roberto [Departmento de Quimica, Universidade Federal de Sao Carlos-UFSCAR, Rod. Washington Luiz, 13565-905 Sao Carlos, SP (Brazil); Golin, Alexsander Luiz [Departmento de Engenharia Mecanica, Faculdade de Engenharia Mecanica, Pontificia Universidade Catolica de Curitiba, Curitiba, PR (Brazil); Aragao, Francisco J.L. [Universidade Catolica de Brasilia, Pos-Graduacao em Ciencias Genomicas e Biotecnologia, SGAN Quadra 916, Modulo B, Av. W5 Norte 70.790-160-Asa Norte Brasilia/DF (Brazil); Embrapa Recursos Geneticos e Biotecnologia, Laboratorio de Introducao e Expressao de Genes, PqEB W5 Norte, 70770-900, Brasilia, DF (Brazil); Cooper, Lyndon F., E-mail: lyndon_cooper@dentistry.unc.edu [Bone Biology and Implant Therapy Laboratory, Department of Prosthodontics, University of North Carolina at Chapel Hill, 404 Brauer Hall, CB 7450, Chapel Hill, NC 27511 (United States)

2011-12-01

The aim of this study was to investigate the response of nanostructured implant surfaces at the level of osteoblast differentiation and its effects in bone-to-implant contact (BIC) and removal-torque values (RTV). CpTi grade IV implants (1.6 x 4.0 mm) were machined or machined and subsequently coated with an oxide solution. The surfaces were divided into: machined (M), titania-anatase (An), titania-rutile (Ru), and zirconia (Zr). Surfaces were examined by scanning electron microscopy, atomic force microscopy, and by X-ray microanalysis. Implants were inserted in rat tibia and harvested from 0 to 21 days for measurement of Alkaline Phosphatase, Bone Sialoprotein, Osteocalcin, Osteopontin, and RUNX-2 mRNA levels by real time PCR; from 0 to 56 days for RTV; and from 0 to 56 days for BIC. The roughness parameter (Sa) was compared by one-way ANOVA followed by Tukey Test. Comparison of Torque removal values and histomorphometric measurements on implants in vivo was performed by Kruskal-Wallis test and the significance level for all statistical analyses was set at p {<=} 0.05. mRNA levels on all nanostructured surfaces were increased compared to M. At 56 days, the mean RTV in Ncm was 11.6 {+-} 2.5, 11.3 {+-} 2.4, 11.1 {+-} 3.5, 9.7 {+-} 1.4 for An, Ru, Zr, and M, respectively. Higher BIC (%) was measured for all the nanostructured surfaces versus M at 21 and 56 days (p < 0.05). Nanostructured topographic features composed of TiO{sub 2} or ZrO{sub 2} applied to machined cpTi implant promoted greater mesenchymal stem cell commitment to the osteoblast phenotype and associated increased BIC and physical association with bone. Highlights: {yields} Nanostructured surfaces using a sol-gel technique coated cpTi with TiO{sub 2} or ZrO{sub 2}. {yields} Evaluated molecular and mechanical effect of nanofeatures in vivo in rat tibiae. {yields} Nanofeatures improved the differentiation of rat MSCs into osteoblasts. {yields} Nanofeatures improved increased bone-to-implant contact and

Nanostructured implant surface effect on osteoblast gene expression and bone-to-implant contact in vivo

International Nuclear Information System (INIS)

Mendonca, Gustavo; Baccelli Silveira Mendonca, Daniela; Pagotto Simoes, Luis Gustavo; Araujo, Andre Luis; Leite, Edson Roberto; Golin, Alexsander Luiz; Aragao, Francisco J.L.; Cooper, Lyndon F.

2011-01-01

The aim of this study was to investigate the response of nanostructured implant surfaces at the level of osteoblast differentiation and its effects in bone-to-implant contact (BIC) and removal-torque values (RTV). CpTi grade IV implants (1.6 x 4.0 mm) were machined or machined and subsequently coated with an oxide solution. The surfaces were divided into: machined (M), titania-anatase (An), titania-rutile (Ru), and zirconia (Zr). Surfaces were examined by scanning electron microscopy, atomic force microscopy, and by X-ray microanalysis. Implants were inserted in rat tibia and harvested from 0 to 21 days for measurement of Alkaline Phosphatase, Bone Sialoprotein, Osteocalcin, Osteopontin, and RUNX-2 mRNA levels by real time PCR; from 0 to 56 days for RTV; and from 0 to 56 days for BIC. The roughness parameter (Sa) was compared by one-way ANOVA followed by Tukey Test. Comparison of Torque removal values and histomorphometric measurements on implants in vivo was performed by Kruskal-Wallis test and the significance level for all statistical analyses was set at p ≤ 0.05. mRNA levels on all nanostructured surfaces were increased compared to M. At 56 days, the mean RTV in Ncm was 11.6 ± 2.5, 11.3 ± 2.4, 11.1 ± 3.5, 9.7 ± 1.4 for An, Ru, Zr, and M, respectively. Higher BIC (%) was measured for all the nanostructured surfaces versus M at 21 and 56 days (p 2 or ZrO 2 applied to machined cpTi implant promoted greater mesenchymal stem cell commitment to the osteoblast phenotype and associated increased BIC and physical association with bone. Highlights: → Nanostructured surfaces using a sol-gel technique coated cpTi with TiO 2 or ZrO 2 . → Evaluated molecular and mechanical effect of nanofeatures in vivo in rat tibiae. → Nanofeatures improved the differentiation of rat MSCs into osteoblasts. → Nanofeatures improved increased bone-to-implant contact and removal torque values. → TiO 2 or ZrO 2 nanofeatures improved the biological response of machined titanium.

Evaluation of Osseointegration of Titanium Alloyed Implants Modified by Plasma Polymerization

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Carolin Gabler

2014-02-01

Full Text Available By means of plasma polymerization, positively charged, nanometre-thin coatings can be applied to implant surfaces. The aim of the present study was to quantify the adhesion of human bone cells in vitro and to evaluate the bone ongrowth in vivo, on titanium surfaces modified by plasma polymer coatings. Different implant surface configurations were examined: titanium alloy (Ti6Al4V coated with plasma-polymerized allylamine (PPAAm and plasma-polymerized ethylenediamine (PPEDA versus uncoated. Shear stress on human osteoblast-like MG-63 cells was investigated in vitro using a spinning disc device. Furthermore, bone-to-implant contact (BIC was evaluated in vivo. Custom-made conical titanium implants were inserted at the medial tibia of female Sprague-Dawley rats. After a follow-up of six weeks, the BIC was determined by means of histomorphometry. The quantification of cell adhesion showed a significantly higher shear stress for MG-63 cells on PPAAm and PPEDA compared to uncoated Ti6Al4V. Uncoated titanium alloyed implants showed the lowest BIC (40.4%. Implants with PPAAm coating revealed a clear but not significant increase of the BIC (58.5% and implants with PPEDA a significantly increased BIC (63.7%. In conclusion, plasma polymer coatings demonstrate enhanced cell adhesion and bone ongrowth compared to uncoated titanium surfaces.

An experimental test of stroke recovery by implanting a hyaluronic acid hydrogel carrying a Nogo receptor antibody in a rat model

International Nuclear Information System (INIS)

Ma Jun; Tian Weiming; Hou Shaoping; Xu Qunyuan; Spector, Myron; Cui Fuzhai

2007-01-01

The objective of the study was to determine the effects of a hyaluronic-acid-based (HA-based) hydrogel implant, carrying a polyclonal antibody to the Nogo-66 receptor (NgR), on adult rats that underwent middle cerebral artery occlusion (MCAO). Behavioral tests of a forelimb-reaching task suggested that the disabled function of the impaired forelimb in this stroke model was ameliorated by the implant to a certain extent. These behavioral findings were correlated with immunohistochemical results of investigating the distribution of NgR antibody, neurofilaments (NF) and neuron-specific class III β-tubulin (TuJ1) in the brain sections. The porous hydrogel functioned as a scaffold to deliver the NgR antibody, support cell migration and development. In addition, it was found NF-positive and TuJ1-positive expressions were distributed in the implanted hydrogel. Collectively, the results demonstrate the promise of the HA hydrogel as a scaffold material and the delivery vehicle of the NgR antibody for the repair of defects and the support of neural regeneration in the brain

An experimental test of stroke recovery by implanting a hyaluronic acid hydrogel carrying a Nogo receptor antibody in a rat model

Energy Technology Data Exchange (ETDEWEB)

Ma Jun [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Tian Weiming [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Hou Shaoping [Beijing Institute of Neuroscience, Capital University of Medical Sciences, Beijing 100054 (China); Xu Qunyuan [Beijing Institute of Neuroscience, Capital University of Medical Sciences, Beijing 100054 (China); Spector, Myron [Tissue Engineering, VA Boston Healthcare System, Harvard Medical School, Boston, MA (United States); Cui Fuzhai [Biomaterials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2007-12-15

The objective of the study was to determine the effects of a hyaluronic-acid-based (HA-based) hydrogel implant, carrying a polyclonal antibody to the Nogo-66 receptor (NgR), on adult rats that underwent middle cerebral artery occlusion (MCAO). Behavioral tests of a forelimb-reaching task suggested that the disabled function of the impaired forelimb in this stroke model was ameliorated by the implant to a certain extent. These behavioral findings were correlated with immunohistochemical results of investigating the distribution of NgR antibody, neurofilaments (NF) and neuron-specific class III {beta}-tubulin (TuJ1) in the brain sections. The porous hydrogel functioned as a scaffold to deliver the NgR antibody, support cell migration and development. In addition, it was found NF-positive and TuJ1-positive expressions were distributed in the implanted hydrogel. Collectively, the results demonstrate the promise of the HA hydrogel as a scaffold material and the delivery vehicle of the NgR antibody for the repair of defects and the support of neural regeneration in the brain.

Gamma radiation and its role in bio prosthetic aortic valves implanted in rat hearts

International Nuclear Information System (INIS)

Lamas, Gloria I.; Kairiyama, Eulogia; Navia, Jose

2000-01-01

Porcine heart valves glutaraldehyde fixed are implanted in patients with valvular deterioration. Mineralization may be the major factor in the long-term failure of tissue bio prosthesis. Gamma radiation randomly breaks some glutaraldehyde cross-links. As a consequence of irradiation, the polymeric fibers belonging to the valvular tissue are broken too, leading to sites of collagen fiber disorganisation. It is well known that the collagen fibers may act as a passive nucleator of salts where the calcium phosphate salts precipitate. This salt concentration has been described in association with disintegrated sites of protein fiber, which may favour new sites where the calcium salts would be deposit. The irradiation process is a technique used for sterilization of porcine heart valve. The main objective of this work was to study the effect of different doses of gamma radiation on the calcification process of subcutaneously implanted valves in rats. Small pieces from glutaraldehyde fixed valves, irradiated to different doses with a 60 Co sources were implanted subcutaneously in rats. The calcium was measured by X-ray and atomic absorption spectrophotometry. In our experimental conditions and at the radiation doses used in these tests, the calcium measurements on control and irradiated material were not significantly different. We conclude that, at the employed doses, the gamma radiation does not alter the process. (author) [es

Long-term erythropoietin gene expression from transduced cells in bioisolator devices.

Science.gov (United States)

Yanay, Ofer; Barry, Simon C; Flint, Lisa Y; Brzezinski, Margaret; Barton, Randall W; Osborne, William R A

2003-11-20

Recombinant erythropoietin (EPO) is widely administered for long-term treatment of anemia associated with renal failure and other chronic diseases. The ability to deliver EPO by gene therapy would have clinical and economic benefit. We compared autologous and allogeneic transduced primary vascular smooth muscle cells for their ability to provide sustained EPO gene expression when encapsulated in TheraCyte devices implanted subcutaneously (SQ) or intraperitoneally (IP) in rats. Cells were transduced with retrovirus vector LrEpSN encoding rat EPO cDNA. Rats that received either autologous or allogeneic transduced cells showed elevated hematocrits (HCTs) ranging from 50 to 79% that were sustained for more than 12 months. The HCT of control rats remained at baseline (45.8%). Rats that received second SQ implants of either autologous or allogeneic cells showed elevations in hematocrit that were sustained for up to 12 months, suggesting the absence of immunological responses to transduced cells or implant material. All experimental groups had statistically significant elevated HCT (p TheraCyte devices was well tolerated and histological evaluation of the devices up to 12 months after surgery revealed a high degree of vascularization and no evidence of host immune response. TheraCyte devices offer a simple and safe gene delivery system that provides sustained therapeutic gene expression, permit removal and implantation of new devices, and do not require immunosuppression of the host.

The synergistic effect of TiO2 nanoporous modification and platelet-rich plasma treatment on titanium-implant stability in ovariectomized rats

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Jiang N

2016-09-01

Full Text Available Nan Jiang,1,2 Pinggong Du,2 Weidong Qu,2 Lin Li,2 Zhonghao Liu,2 Songsong Zhu1 1State Key Laboratory of Oral Diseases and Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, 2Yantai City Stomatological Hospital, Yantai, People’s Republic of China Abstract: For several decades, titanium and its alloys have been commonly utilized for endosseous implantable materials, because of their good mechanical properties, chemical resistance, and biocompatibility. But associated low bone mass, wear and loss characteristics, and high coefficients of friction have limited their long-term stable performance, especially in certain abnormal bone-metabolism conditions, such as postmenopausal osteoporosis. In this study, we investigated the effects of platelet-rich plasma (PRP treatment and TiO2 nanoporous modification on the stability of titanium implants in osteoporotic bone. After surface morphology, topographical structure, and chemical changes of implant surface had been detected by scanning electron microscopy (SEM, atomic force microscopy, contact-angle measurement, and X-ray diffraction, we firstly assessed in vivo the effect of PRP treatment on osseointegration of TiO2-modified implants in ovariectomized rats by microcomputed tomography examinations, histology, biomechanical testing, and SEM observation. Meanwhile, the potential molecular mechanism involved in peri-implant osseous enhancement was also determined by quantitative real-time polymerase chain reaction. The results showed that this TiO2-modified surface was able to lead to improve bone implant contact, while PRP treatment was able to increase the implant surrounding bone mass. The synergistic effect of both was able to enhance the terminal force of implants drastically in biomechanical testing. Compared with surface modification, PRP treatment promoted earlier osteogenesis with increased expression of the RUNX2 and COL1 genes and

Implantable porous gelatin microspheres sustained release of bFGF and improved its neuroprotective effect on rats after spinal cord injury.

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Li Lan

Full Text Available In this study, porous gelatin microspheres (GMSs were constructed to improve the neuroprotective effect of basic fibroblast growth factor (bFGF on spinal cord injury. GMSs were prepared by a W/O emulsion template, followed by cross-linking, washing and drying. The particle sizes and surface porosity of the blank GMSs were carefully characterized by scan electronic microscopy. The blank GMSs have a mean particle size of 35μm and theirs surface was coarse and porous. bFGF was easily encapsulated inside the bulk GMSs through diffusion along the porous channel. 200μg of bFGF was completely encapsulated in 100mg of GMSs. The bFGF-loaded GMSs displayed a continuous drug release pattern without an obvious burst release over two weeks in vitro. Moreover, the therapeutic effects of bFGF-loaded GMSs were also evaluated in spinal cord injury rat model. After implantation of bFGF-loaded GMSs, the recovery of the motor function of SCI rats were evaluated by behavioral score and foot print experiment. The motor function of SCI rats treated with bFGF-loaded GMSs was more obvious than that treated with free bFGF solution (P<0.05. At the 28th days after treatment, rats were sacrificed and the injured spinal were removed for histopathological and apoptosis examination. Compared with treatment with free bFGF solution, treatment with bFGF-loaded GMSs resulted in a less necrosis, less infiltration of leukocytes, and a reduced the cavity ratio and less apoptotic cells in injured spinal(P<0.01, indicating its better therapeutic effect. Implantable porous GMSs may be a potential carrier to deliver bFGF for therapy of spinal cord injury.

Lumbar spine intervertebral disc gene delivery: a pilot study in lewis rats.

Science.gov (United States)

Damle, Sheela R; Rawlins, Bernard A; Boachie-Adjei, Oheneba; Crystal, Ronald G; Hidaka, Chisa; Cunningham, Matthew E

2013-02-01

Basic research toward understanding and treating disc pathology in the spine has utilized numerous animal models, with delivery of small molecules, purified factors, and genes of interest. To date, gene delivery to the rat lumbar spine has only been described utilizing genetically programmed cells in a matrix which has required partial disc excision, and expected limitation of treatment diffusion into the disc. This study was designed to develop and describe a surgical technique for lumbar spine exposure and disc space preparation, and use of a matrix-free method for gene delivery. Naïve or genetically programmed isogeneic bone marrow stromal cells were surgically delivered to adolescent male Lewis rat lumbar discs, and utilizing quantitative biochemical and qualitative immunohistological assessments, the implanted cells were detected 3 days post-procedure. Statistically significant differences were noted for recovery of the β-galactosidase marker gene comparing delivery of naïve or labeled cells (10(5) cells per disc) from the site of implantation, and between delivery of 10(5) or 10(6) labeled cells per disc at the site of implantation and the adjacent vertebral body. Immunohistology confirmed that the β-galactosidase marker was detected in the adjacent vertebra bone in the zone of surgical implantation. The model requires further testing in larger cohorts and with biologically active genes of interest, but the observations from the pilot experiments are very encouraging that this will be a useful comparative model for basic spine research involving gene or cell delivery, or other locally delivered therapies to the intervertebral disc or adjacent vertebral bodies in rats.

In Vitro and In Vivo Osteogenic Activity of Titanium Implants Coated by Pulsed Laser Deposition with a Thin Film of Fluoridated Hydroxyapatite

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Luyuan Chen

2018-04-01

Full Text Available To enhance biocompatibility, osteogenesis, and osseointegration, we coated titanium implants, by krypton fluoride (KrF pulsed laser deposition, with a thin film of fluoridated hydroxyapatite (FHA. Coating was confirmed by scanning electron microscopy (SEM and scanning probe microscopy (SPM, while physicochemical properties were evaluated by attenuated reflectance Fourier transform infrared spectroscopy (ATR-FTIR. Calcium deposition, osteocalcin production, and expression of osteoblast genes were significantly higher in rat bone marrow mesenchymal stem cells seeded on FHA-coated titanium than in cells seeded on uncoated titanium. Implantation into rat femurs also showed that the FHA-coated material had superior osteoinductive and osseointegration activity in comparison with that of traditional implants, as assessed by microcomputed tomography and histology. Thus, titanium coated with FHA holds promise as a dental implant material.

[Significance of various implantate localizations of Sparks prostheses, experimental studies in rats].

Science.gov (United States)

Brieler, H S; Parwaresch, R; Thiede, A

1976-01-01

Our investigations show that Sparks prostheses after subcutaneous implantation are suitable for vascular grafting. At the end of the organization period the connective tissue becomes strong, and after the third and fourth weeks collagenous and elastic fibers can be seen. Ten weeks after s.c. implantation, collagenous fibers predominate. After this the Sparks prostheses can be used as a vascular graft. Intraperitoneal implantation, however, shows a histologically different picture with characteristic findings: only fat cells can be observed, a strong granulation tissue with elastic and collagenous fibers is not present. After intraperitoneal implantation Sparks prostheses are therefore unsuitable for vascular grafts.

Silk fibroin/chitosan thin film promotes osteogenic and adipogenic differentiation of rat bone marrow-derived mesenchymal stem cells.

Science.gov (United States)

Li, Da-Wei; He, Jin; He, Feng-Li; Liu, Ya-Li; Liu, Yang-Yang; Ye, Ya-Jing; Deng, Xudong; Yin, Da-Chuan

2018-04-01

As a biodegradable polymer thin film, silk fibroin/chitosan composite film overcomes the defects of pure silk fibroin and chitosan films, respectively, and shows remarkable biocompatibility, appropriate hydrophilicity and mechanical properties. Silk fibroin/chitosan thin film can be used not only as metal implant coating for bone injury repair, but also as tissue engineering scaffold for skin, cornea, adipose, and other soft tissue injury repair. However, the biocompatibility of silk fibroin/chitosan thin film for mesenchymal stem cells, a kind of important seed cell of tissue engineering and regenerative medicine, is rarely reported. In this study, silk fibroin/chitosan film was prepared by solvent casting method, and the rat bone marrow-derived mesenchymal stem cells were cultured on the silk fibroin/chitosan thin film. Osteogenic and adipogenic differentiation of rat bone marrow-derived mesenchymal stem cells were induced, respectively. The proliferation ability, osteogenic and adipogenic differentiation abilities of rat bone marrow-derived mesenchymal stem cells were systematically compared between silk fibroin/chitosan thin film and polystyrene tissue culture plates. The results showed that silk fibroin/chitosan thin film not only provided a comparable environment for the growth and proliferation of rat bone marrow-derived mesenchymal stem cells but also promoted their osteogenic and adipogenic differentiation. This work provided information of rat bone marrow-derived mesenchymal stem cells behavior on silk fibroin/chitosan thin film and extended the application of silk fibroin/chitosan thin film. Based on the results, we suggested that the silk fibroin/chitosan thin film could be a promising material for tissue engineering of bone, cartilage, adipose, and skin.

Neuromuscular junction formation between human stem-cell-derived motoneurons and rat skeletal muscle in a defined system.

Science.gov (United States)

Guo, Xiufang; Das, Mainak; Rumsey, John; Gonzalez, Mercedes; Stancescu, Maria; Hickman, James

2010-12-01

To date, the coculture of motoneurons (MNs) and skeletal muscle in a defined in vitro system has only been described in one study and that was between rat MNs and rat skeletal muscle. No in vitro studies have demonstrated human MN to rat muscle synapse formation, although numerous studies have attempted to implant human stem cells into rat models to determine if they could be of therapeutic use in disease or spinal injury models, although with little evidence of neuromuscular junction (NMJ) formation. In this report, MNs differentiated from human spinal cord stem cells, together with rat skeletal myotubes, were used to build a coculture system to demonstrate that NMJ formation between human MNs and rat skeletal muscles is possible. The culture was characterized by morphology, immunocytochemistry, and electrophysiology, while NMJ formation was demonstrated by immunocytochemistry and videography. This defined system provides a highly controlled reproducible model for studying the formation, regulation, maintenance, and repair of NMJs. The in vitro coculture system developed here will be an important model system to study NMJ development, the physiological and functional mechanism of synaptic transmission, and NMJ- or synapse-related disorders such as amyotrophic lateral sclerosis, as well as for drug screening and therapy design.

Dietary linoleate preserves cardiolipin and attenuates mitochondrial dysfunction in the failing rat heart

Science.gov (United States)

Mulligan, Christopher M.; Sparagna, Genevieve C.; Le, Catherine H.; De Mooy, Anthony B.; Routh, Melissa A.; Holmes, Michael G.; Hickson-Bick, Diane L.; Zarini, Simona; Murphy, Robert C.; Xu, Fred Y.; Hatch, Grant M.; McCune, Sylvia A.; Moore, Russell L.; Chicco, Adam J.

2012-01-01

Aims Cardiolipin (CL) is a tetra-acyl phospholipid that provides structural and functional support to several proteins in the inner mitochondrial membrane. The majority of CL in the healthy mammalian heart contains four linoleic acid acyl chains (L4CL). A selective loss of L4CL is associated with mitochondrial dysfunction and heart failure in humans and animal models. We examined whether supplementing the diet with linoleic acid would preserve cardiac L4CL and attenuate mitochondrial dysfunction and contractile failure in rats with hypertensive heart failure. Methods and results Male spontaneously hypertensive heart failure rats (21 months of age) were administered diets supplemented with high-linoleate safflower oil (HLSO) or lard (10% w/w; 28% kilocalorie fat) or without supplemental fat (control) for 4 weeks. HLSO preserved L4CL and total CL to 90% of non-failing levels (vs. 61–75% in control and lard groups), and attenuated 17–22% decreases in state 3 mitochondrial respiration observed in the control and lard groups (P < 0.05). Left ventricular fractional shortening was significantly higher in HLSO vs. control (33 ± 2 vs. 29 ± 2%, P < 0.05), while plasma insulin levels were lower (5.4 ± 1.1 vs. 9.1 ± 2.3 ng/mL; P < 0.05), with no significant effect of lard supplementation. HLSO also increased serum concentrations of several eicosanoid species compared with control and lard diets, but had no effect on plasma glucose or blood pressure. Conclusion Moderate consumption of HLSO preserves CL and mitochondrial function in the failing heart and may be a useful adjuvant therapy for this condition. PMID:22411972

Sugar for the fuel cell. Micro fuel cells for implants; Gib der Brennstoffzelle Zucker. Mikro-Brennstoffzellen fuer Implantate

Energy Technology Data Exchange (ETDEWEB)

Geitmann, Sven

2012-04-15

Scientists are working on micro fuel cells that will be capable of generating electric power from blood glucose. This may be an option for providing energy to cardiac pacemakers, hearing aids and other medical implants on a long-term basis. Surgery for battery exchange would be unnecessary, and patients would enjoy a better quality of life. In Germany, more than 70,000 cardiac pacemakers are implanted every year; batteries must be exchanged after about eight years. (orig.)

Acid etching and plasma sterilization fail to improve osseointegration of grit blasted titanium implants

DEFF Research Database (Denmark)

Mortensen, Mikkel Saksø; Jakobsen, Stig Storgaard; Saksø, Henrik

2012-01-01

Interaction between implant surface and surrounding bone influences implant fixation. We attempted to improve the bone-implant interaction by 1) adding surface micro scale topography by acid etching, and 2) removing surface-adherent pro-inflammatory agents by plasma cleaning. Implant fixation...... was evaluated by implant osseointegration and biomechanical fixation.The study consisted of two paired animal sub-studies where 10 skeletally mature Labrador dogs were used. Grit blasted titanium alloy implants were inserted press fit in each proximal tibia. In the first study grit blasted implants were...... compared with acid etched grit blasted implants. In the second study grit blasted implants were compared with acid etched grit blasted implants that were further treated with plasma sterilization. Implant performance was evaluated by histomorphometrical investigation (tissue-to-implant contact, peri-implant...

A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

Science.gov (United States)

Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

2014-02-01

Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.

Estrogen supplementation failed to attenuate biochemical indices of neutrophil infiltration or damage in rat skeletal muscles following ischemia.

Science.gov (United States)

Tiidus, Peter M; Deller, Mirada; Bombardier, Eric; Gül, Mustafa; Liu, X Linda

2005-01-01

This study examined the effects of estrogen supplementation on markers of neutrophil infiltration and damage in skeletal muscle of rats following ischemia. Male and female gonad-intact rats, with or without 14 days of estrogen supplementation were subjected to two hours of hind-limb ischemia and sacrificed at 24, 48 or 72 hours post-ischemia. Control animals were sacrificed without ischemia. Plantaris and red and white gastrocneimus muscles were removed and assayed for myeloperoxidase (MPO), a marker of neutrophil infiltration, and glucose-6-phosphate dehydrogenase (G6PD) and beta-glucuronidase (betaGLU), as markers of muscle damage. Significant elevations of MPO, G6PD and betaGLU activities were observed at various time points post-ischemia. No systematic differences between genders were noted in any of the measures. Estrogen supplementation in both male and female animals failed to significantly attenuate post-ischemia increases in MPO, G6PD and betaGLU activities in any of the muscles studied and in some cases accentuated activities of some of these measures. Unlike previous findings following exercise in skeletal muscle, this study failed to demonstrate estrogen-induced attenuation of indices of neutrophil infiltration or damage in skeletal muscles of rats up to 72 hours following ischemia. This demonstrates that estrogen may not consistently attenuate neutrophil infiltration and that a number of variables including damage modality, tissue or estrogen level may influence this.

Estrogen supplementation failed to attenuate biochemical indices of neutrophil infiltration or damage in rat skeletal muscles following ischemia

Directory of Open Access Journals (Sweden)

PETER M TIIDUS

2005-01-01

Full Text Available This study examined the effects of estrogen supplementation on markers of neutrophil infiltration and damage in skeletal muscle of rats following ischemia. Male and female gonad-intact rats, with or without 14 days of estrogen supplementation were subjected to two hours of hind-limb ischemia and sacrificed at 24, 48 or 72 hours post-ischemia. Control animals were sacrificed without ischemia. Plantaris and red and white gastrocneimus muscles were removed and assayed for myeloperoxidase (MPO, a marker of neutrophil infiltration, and glucose-6-phosphate dehydrogenase (G6PD and ß-glucuronidase (GLU, as markers of muscle damage. Significant elevations of MPO, G6PD and GLU activities were observed at various time points post-ischemia. No systematic differences between genders were noted in any of the measures. Estrogen supplementation in both male and female animals failed to significantly attenuate post-ischemia increases in MPO, G6PD and GLU activities in any of the muscles studied and in some cases accentuated activities of some of these measures. Unlike previous findings following exercise in skeletal muscle, this study failed to demonstrate estrogen-induced attenuation of indices of neutrophil infiltration or damage in skeletal muscles of rats up to 72 hours following ischemia. This demonstrates that estrogen may not consistently attenuate neutrophil infiltration and that a number of variables including damage modality, tissue or estrogen level may influence this.

Gingival Mesenchymal Stem Cell (GMSC) Delivery System Based on RGD-Coupled Alginate Hydrogel with Antimicrobial Properties: A Novel Treatment Modality for Peri-Implantitis.

Science.gov (United States)

Diniz, Ivana M A; Chen, Chider; Ansari, Sahar; Zadeh, Homayoun H; Moshaverinia, Maryam; Chee, Daniel; Marques, Márcia M; Shi, Songtao; Moshaverinia, Alireza

2016-02-01

Peri-implantitis is one of the most common inflammatory complications in dental implantology. Similar to periodontitis, in peri-implantitis, destructive inflammatory changes take place in the tissues surrounding a dental implant. Bacterial flora at the failing implant sites resemble the pathogens in periodontal disease and consist of Gram-negative anaerobic bacteria including Aggregatibacter actinomycetemcomitans (Aa). Here we demonstrate the effectiveness of a silver lactate (SL)-containing RGD-coupled alginate hydrogel scaffold as a promising stem cell delivery vehicle with antimicrobial properties. Gingival mesenchymal stem cells (GMSCs) or human bone marrow mesenchymal stem cells (hBMMSCs) were encapsulated in SL-loaded alginate hydrogel microspheres. Stem cell viability, proliferation, and osteo-differentiation capacity were analyzed. Our results showed that SL exhibited antimicrobial properties against Aa in a dose-dependent manner, with 0.50 mg/ml showing the greatest antimicrobial properties while still maintaining cell viability. At this concentration, SL-containing alginate hydrogel was able to inhibit Aa growth on the surface of Ti discs and significantly reduce the bacterial load in Aa suspensions. Silver ions were effectively released from the SL-loaded alginate microspheres for up to 2 weeks. Osteogenic differentiation of GMSCs and hBMMSCs encapsulated in the SL-loaded alginate microspheres were confirmed by the intense mineral matrix deposition and high expression of osteogenesis-related genes. Taken together, our findings confirm that GMSCs encapsulated in RGD-modified alginate hydrogel containing SL show promise for bone tissue engineering with antimicrobial properties against Aa bacteria in vitro. © 2015 by the American College of Prosthodontists.

Permanently Hypoxic Cell Culture Yields Rat Bone Marrow Mesenchymal Cells with Higher Therapeutic Potential in the Treatment of Chronic Myocardial Infarction

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Yihua Liu

2017-11-01

Full Text Available Background: The mismatch between traditional in vitro cell culture conditions and targeted chronic hypoxic myocardial tissue could potentially hamper the therapeutic effects of implanted bone marrow mesenchymal stem cells (BMSCs. This study sought to address (i the extent of change to BMSC biological characteristics in different in vitro culture conditions and (ii the effectiveness of permanent hypoxic culture for cell therapy in treating chronic myocardial infarction (MI in rats. Methods: rat BMSCs were harvested and cultured in normoxic (21% O2, n=27 or hypoxic conditions (5% O2, n=27 until Passage 4 (P4. Cell growth tests, flow cytometry, and Bio-Plex assays were conducted to explore variations in the cell proliferation, phenotype, and cytokine expression, respectively. In the in vivo set-up, P3-BMSCs cultured in normoxia (n=6 or hypoxia (n=6 were intramyocardially injected into rat hearts that had previously experienced 1-month-old MI. The impact of cell therapy on cardiac segmental viability and hemodynamic performance was assessed 1 month later by 2-Deoxy-2[18F]fluoro-D-glucose (18F-FDG positron emission tomography (PET imaging and pressure-volume catheter, respectively. Additional histomorphological examinations were conducted to evaluate inflammation, fibrosis, and neovascularization. Results: Hypoxic preconditioning significantly enhanced rat BMSC clonogenic potential and proliferation without altering the multipotency. Different profiles of inflammatory, fibrotic, and angiogenic cytokine secretion were also documented, with a marked correlation observed between in vitro and in vivo proangiogenic cytokine expression and tissue neovessels. Hypoxic-preconditioned cells presented a beneficial effect on the myocardial viability of infarct segments and intrinsic contractility. Conclusion: Hypoxic-preconditioned BMSCs were able to benefit myocardial perfusion and contractility, probably by modulating the inflammation and promoting

Permanently Hypoxic Cell Culture Yields Rat Bone Marrow Mesenchymal Cells with Higher Therapeutic Potential in the Treatment of Chronic Myocardial Infarction.

Science.gov (United States)

Liu, Yihua; Yang, Xiaoxi; Maureira, Pablo; Falanga, Aude; Marie, Vanessa; Gauchotte, Guillaume; Poussier, Sylvain; Groubatch, Frederique; Marie, Pierre-Yves; Tran, Nguyen

2017-01-01

The mismatch between traditional in vitro cell culture conditions and targeted chronic hypoxic myocardial tissue could potentially hamper the therapeutic effects of implanted bone marrow mesenchymal stem cells (BMSCs). This study sought to address (i) the extent of change to BMSC biological characteristics in different in vitro culture conditions and (ii) the effectiveness of permanent hypoxic culture for cell therapy in treating chronic myocardial infarction (MI) in rats. rat BMSCs were harvested and cultured in normoxic (21% O2, n=27) or hypoxic conditions (5% O2, n=27) until Passage 4 (P4). Cell growth tests, flow cytometry, and Bio-Plex assays were conducted to explore variations in the cell proliferation, phenotype, and cytokine expression, respectively. In the in vivo set-up, P3-BMSCs cultured in normoxia (n=6) or hypoxia (n=6) were intramyocardially injected into rat hearts that had previously experienced 1-month-old MI. The impact of cell therapy on cardiac segmental viability and hemodynamic performance was assessed 1 month later by 2-Deoxy-2[18F]fluoro-D-glucose (18F-FDG) positron emission tomography (PET) imaging and pressure-volume catheter, respectively. Additional histomorphological examinations were conducted to evaluate inflammation, fibrosis, and neovascularization. Hypoxic preconditioning significantly enhanced rat BMSC clonogenic potential and proliferation without altering the multipotency. Different profiles of inflammatory, fibrotic, and angiogenic cytokine secretion were also documented, with a marked correlation observed between in vitro and in vivo proangiogenic cytokine expression and tissue neovessels. Hypoxic-preconditioned cells presented a beneficial effect on the myocardial viability of infarct segments and intrinsic contractility. Hypoxic-preconditioned BMSCs were able to benefit myocardial perfusion and contractility, probably by modulating the inflammation and promoting angiogenesis. © 2017 The Author(s). Published by S. Karger AG

A simple ion implantation system for solar cells

International Nuclear Information System (INIS)

Kenny, M.J.; Bird, J.R.; Broe, H.G.

1982-11-01

A project has been initiated to investigate simple but effective ion implantation and pulsed annealing techniques for the fabrication of high efficiency silicon solar cells. In particular, the method aims to eliminate the mass analyser and associated components from the implanter. A solid feed source is used in a clean ultra high vacuum environment to minimise impurities

Maintained functionality of an implantable radiotelemetric blood pressure and heart rate sensor after magnetic resonance imaging in rats

International Nuclear Information System (INIS)

Nölte, I; Boll, H; Figueiredo, G; Groden, C; Brockmann, M A; Gorbey, S; Lemmer, B

2011-01-01

Radiotelemetric sensors for in vivo assessment of blood pressure and heart rate are widely used in animal research. MRI with implanted sensors is regarded as contraindicated as transmitter malfunction and injury of the animal may be caused. Moreover, artefacts are expected to compromise image evaluation. In vitro, the function of a radiotelemetric sensor (TA11PA-C10, Data Sciences International) after exposure to MRI up to 9.4 T was assessed. The magnetic force of the electromagnetic field on the sensor as well as radiofrequency (RF)-induced sensor heating was analysed. Finally, MRI with an implanted sensor was performed in a rat. Imaging artefacts were analysed at 3.0 and 9.4 T ex vivo and in vivo. Transmitted 24 h blood pressure and heart rate were compared before and after MRI to verify the integrity of the telemetric sensor. The function of the sensor was not altered by MRI up to 9.4 T. The maximum force exerted on the sensor was 273 ± 50 mN. RF-induced heating was ruled out. Artefacts impeded the assessment of the abdomen and thorax in a dead rat, but not of the head and neck. MRI with implanted radiotelemetric sensors is feasible in principal. The tested sensor maintains functionality up to 9.4 T. Artefacts hampered abdominal and throacic imaging in rats, while assessment of the head and neck is possible

Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

International Nuclear Information System (INIS)

Nikolaev, A.G.; Yushkov, G.Yu.; Oks, E.M.; Oztarhan, A.; Akpek, A.; Hames-Kocabas, E.; Urkac, E.S.; Brown, I.G.

2014-01-01

Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material

Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

Energy Technology Data Exchange (ETDEWEB)

Nikolaev, A.G., E-mail: nik@opee.hcei.tsc.ru [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Yushkov, G.Yu.; Oks, E.M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Oztarhan, A. [Izmir University, Izmir 35140 (Turkey); Akpek, A.; Hames-Kocabas, E.; Urkac, E.S. [Bioengineering Department, Ege University, Bornova 35100, Izmir (Turkey); Brown, I.G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94708 (United States)

2014-08-15

Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material.

Assessment of implantable infusion pumps for continuous infusion of human insulin in rats: potential for group housing

DEFF Research Database (Denmark)

Jensen, Vivi Flou Hjorth; Molck, Anne-Marie; Martensson, Martin

2017-01-01

compound in these studies, and a comparator model of persistent exposure by HI infusion from external pumps has recently been developed to support toxicological evaluation of long-acting insulin analogues. However, this model requires single housing of the animals. Developing an insulin-infusion model...... which allows group housing would therefore greatly improve animal welfare. The aim of the present study was to investigate the suitability of implantable infusion pumps for HI infusion in group-housed rats. Group housing of rats implanted with a battery-driven pump proved to be possible. Intravenous...... infusion of HI lowered blood glucose levels persistently for two weeks, providing a comparator model for use in two-week repeated-dose toxicity studies with new long-acting insulin analogues, which allows group housing, and thereby increasing animal welfare compared with an external infusion model....

Therapeutic effects of NogoA vaccine and olfactory ensheathing glial cell implantation on acute spinal cord injury

Directory of Open Access Journals (Sweden)

Zhang Z

2013-10-01

Full Text Available Zhicheng Zhang, Fang Li, Tiansheng Sun, Dajiang Ren, Xiumei Liu PLA Institute of Orthopedics, Beijing Army General Hospital, Beijing, People's Republic of China Background: Many previous studies have focused on the effects of IN-1, a monoclonal antibody that neutralizes Nogo (a neurite growth inhibitory protein, on neurologic regeneration in spinal cord injury (SCI. However, safety problems and the short half-life of the exogenous antibody are still problematic. In the present study, the NogoA polypeptide was used as an antigen to make a therapeutic NogoA vaccine. Rats were immunized with this vaccine and were able to secrete the polyclonal antibody before SCI. The antibody can block NogoA within the injured spinal cord when the antibody gains access to the spinal cord due to a compromised blood–spinal cord barrier. Olfactory ensheathing glial cell transplantation has been used in a spinal cord contusion model to promote the recovery of SCI. The present study was designed to verify the efficacy and safety of NogoA polypeptide vaccine, the effects of immunotherapy with this vaccine, and the synergistic effects of the vaccine and olfactory ensheathing glial cells in repair of SCI. Methods: A 13-polypeptide fragment of NogoA was synthesized. This fragment was then coupled with keyhole limpet hemocyanin to improve the immunogenicity of the polypeptide vaccine. Immunization via injection into the abdominal cavity was performed in rats before SCI. The serum antibody level and ability of the vaccine to bind with Nogo were detected by enzyme-linked immunosorbent assay. The safety of the vaccine was evaluated according to the incidence and severity of experimental autoimmune encephalomyelitis. Olfactory ensheathing glia cells were obtained, purified, and subsequently implanted into a Wistar rat model of thoracic spinal cord contusion injury. The rats were divided into four groups, ie, an SCI model group, an olfactory ensheathing glia group, a vaccine

Treatment of diabetic rats with encapsulated islets

OpenAIRE

Sweet, Ian R; Yanay, Ofer; Waldron, Lanaya; Gilbert, Merle; Fuller, Jessica M; Tupling, Terry; Lernmark, Ake; Osborne, William R A

2008-01-01

Immunoprotection of islets using bioisolator systems permits introduction of allogeneic cells to diabetic patients without the need for immunosuppression. Using TheraCyte? immunoisolation devices, we investigated two rat models of type 1 diabetes mellitus (T1DM), BB rats and rats made diabetic by streptozotocin (STZ) treatment. We chose to implant islets after the onset of diabetes to mimic the probable treatment of children with T1DM as they are usually diagnosed after disease onset. We enca...

Effect of ovariectomy and 17 beta-estradiol implantation on bone metabolism in female rats fed 1,25 dihydroxyvitamin D3

International Nuclear Information System (INIS)

Osborne, M.; Sherman, S.; Soares, J.H. Jr.

1986-01-01

Eight-week old Sprague-Dawley female rats were used in two experiments to test the effects of 17-B estradiol (E 2 ) via silastic tubing implants on 3 H-labelled tetracycline (TC) incorporation into bone. 1,25(OH) 2 D 3 was the dietary source of vitamin D in a low calcium (.2%) semipurified eggwhite diet. In experiment I, the Ovx + E 2 animals showed a significantly (p 3 H TC uptake in scapula during a 2-week labelling experiment. An increase in 3 H TC content resulted (p 2 was implanted in 1,25(OH) 2 D 3 fed Ovx rats. However, the calcium content was not significantly different. The effect of dietary 1,25(OH) 2 D 3 and E 2 implantation appears to be additive. Optimal action of the Vitamin D endocrine system may be dependent on presence of E 2

Optimization of cell adhesion on mg based implant materials by pre-incubation under cell culture conditions.

Science.gov (United States)

Willumeit, Regine; Möhring, Anneke; Feyerabend, Frank

2014-05-05

Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture.

Optimization of Cell Adhesion on Mg Based Implant Materials by Pre-Incubation under Cell Culture Conditions

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Regine Willumeit

2014-05-01

Full Text Available Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture.

The effects of implant topography on osseointegration under estrogen deficiency induced osteoporotic conditions: Histomorphometric, transcriptional and ultrastructural analysis.

Science.gov (United States)

Du, Zhibin; Xiao, Yin; Hashimi, Saeed; Hamlet, Stephen M; Ivanovski, Saso

2016-09-15

Compromised bone quality and/or healing in osteoporosis are recognised risk factors for impaired dental implant osseointegration. This study examined the effects of (1) experimentally induced osteoporosis on titanium implant osseointegration and (2) the effect of modified implant surface topography on osseointegration under osteoporosis-like conditions. Machined and micro-roughened surface implants were placed into the maxillary first molar root socket of 64 ovariectomised and sham-operated Sprague-Dawley rats. Subsequent histological and SEM observations showed tissue maturation on the micro-rough surfaced implants in ovariectomised animals as early as 3days post-implantation. The degree of osseointegration was also significantly higher around the micro-rough implants in ovariectomised animals after 14days of healing although by day 28, similar levels of osseointegration were found for all test groups. The micro-rough implants significantly increased the early (day 3) gene expression of alkaline phosphatase, osteocalcin, receptor activator of nuclear factor kappa-B ligand and dentin matrix protein 1 in implant adherent cells. By day 7, the expression of inflammatory genes decreased while the expression of the osteogenic markers increased further although there were few statistically significant differences between the micro-rough and machined surfaces. Osteocyte morphology was also affected by estrogen deficiency with the size of the cells being reduced in trabecular bone. In conclusion, estrogen deficiency induced osteoporotic conditions negatively influenced the early osseointegration of machined implants while micro-rough implants compensated for these deleterious effects by enhancing osteogenic cell differentiation on the implant surface. Lower bone density, poor bone quality and osseous microstructural changes are all features characteristic of osteoporosis that may impair the osseointegration of dental implants. Using a clinically relevant trabecular bone

The effects of metformin on ovum implantation and pregnancy outcome in rats with induced PCOS

Directory of Open Access Journals (Sweden)

Mesbah F

2011-06-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Polycystic ovary syndrome (PCOS is the most common cause of anovulatory infertility. Metformin which is effectively used for the treatment of anovulatory PCOS improves pregnancy rate and endometrial receptivity and reduces the risk of miscarriage. The aim of this study was to evaluate the effects of metformin on the endometrium, the number of fetuses and hormonal levels of PCOS rats."n"nMethods: Forty female adult Sprague-Dawley rats were assigned randomly into four equal groups. Group I: control rats, group II: rats receiving metformin (150 mg/kg/day, group III: Estradiol Valerate-induced PCOS rats (4 mg/rat and group IV: induced PCOS rats receiving metformin. Body weight and serum levels of glucose, LH, FSH, testosterone, progesterone and estradiol were measured. Following mating, each group was divided into two subgroups and the rats were sacrificed on the 5th and 15th day of gestation to evaluate endometrial reaction to implantation and fetus count, respectively."n"nResults: Hormone assay showed a significant increase in testosterone, estradiol, LH, FSH and blood glucose levels in group III compared to the controls (P≤0.01 and a significant decrease in blood glucose in group IV versus group III (P≤0

Lithium chloride enhances bone regeneration and implant osseointegration in osteoporotic conditions.

Science.gov (United States)

Jin, Yifan; Xu, Lihua; Hu, Xiaohui; Liao, Shixian; Pathak, Janak L; Liu, Jinsong

2016-10-06

Osteoporotic patients have a high risk of dental and orthopedic implant failure. Lithium chloride (LiCl) has been reported to enhance bone formation. However, the role of LiCl in the success rate of dental and orthopedic implants in osteoporotic conditions is still unknown. We investigated whether LiCl enhances implant osseointegration, implant fixation, and bone formation in osteoporotic conditions. Sprague-Dawley female rats (n = 18) were ovariectomized (OVX) to induce osteoporosis, and another nine rats underwent sham surgery. Three months after surgery, titanium implants were implanted in the tibia of the OVX and sham group rats. After implantation, the OVX rats were gavaged with 150 mg/kg/2 days of LiCl (OVX + LiCl group) or saline (OVX group), and sham group rats were gavaged with saline for 3 months. Implant osseointegration and bone formation were analyzed using histology, biomechanical testing, and micro computed tomography (micro-CT). More bone loss was observed in the OVX group compared to the control, and LiCl treatment enhanced bone formation and implant fixation in osteoporotic rats. In the OVX group, bone-implant contact (BIC) was decreased by 81.2 % compared to the sham group. Interestingly, the OVX + LiCl group showed 4.4-fold higher BIC compared to the OVX group. Micro-CT data of tibia from the OVX + LiCl group showed higher bone volume, trabecular thickness, trabecular number, and osseointegration compared to the OVX group. Maximum push-out force and implant-bone interface shear strength were 2.9-fold stronger in the OVX + LiCl group compared to the OVX group. In conclusion, LiCl enhanced implant osseointegration, implant fixation, and bone formation in osteoporotic conditions, suggesting LiCl as a promising therapeutic agent to prevent implant failure and bone loss in osteoporotic conditions.

Histological study on acute inflammatory reaction to polyurethane-coated silicone implants in rats Estudo histológico da reação inflamatória aguda ao implante de silicone revestido com poliuretano em ratos

Directory of Open Access Journals (Sweden)

Paulo Roberto da Silva Mendes

2008-02-01

Full Text Available PURPOSE: Evaluating histologically the silicone peri-implant coated by polyurethane inflammation associated to the use of anti-microbial and bacterial contamination. METHODS: It was used 35 Wistar rats. The animals were divided in seven groups: I - Control; II - implant cavity contamination with10 bacteria/ml; III - implant cavity contamination with 10 bacteria/ml; IV - implant cavity contamination with 10 bacteria/ml; V - identical contamination to group II and implant immersions in anti-microbial solution; VI - identical contamination in group III and implant immersions in the anti-microbial solution; VII - identical contamination of group IV and implant immersions in anti-microbial solution. It was evaluated morphometrically the peri-implant capsules after 30 days of introduction. RESULTS: The factors with more discriminating power were the giants cells of a strange body and the mononuclear. There was no correlation between the bacterial concentrations and the histological alterations. CONCLUSION: 1 The histological standard of the inflammatory reaction around the silicone implant coated with polyurethan is chronic granulomatosis type of a strange body; 2 There isn´t correlation between concentration of Staphylococcus epidermidis and histological changes; 3 The use of anti-microbial solution decreased the mononuclear cell reactions, with the increase of giant cells in a strange body.OBJETIVO: Avaliar, histologicamente, a reação inflamatória aos implantes de silicone revestidos por poliuretano, com contaminação bacteriana, associada ou não ao uso de antimicrobianos. MÉTODOS: Utilizou-se 35 ratos Wistar. Os animais foram divididos em 7 grupos: I- Controle, II- contaminação da cavidade do implante com 10¹ bactérias/ml, III- contaminação da cavidade do implante com 10³ bactérias/ml, IV- contaminação da cavidade do implante com 10(5 bactérias/ml, V- contaminação idêntica ao grupo II e imersão dos implantes em solu

High-grade Angiosarcoma Associated with Ruptured Breast Implants

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Nicolas R. Smoll, MBBS

2013-04-01

Full Text Available Summary: Since the serendipitous discovery that implanted polymers cause sarcomas in rats, much research has been conducted to prove or disprove a link between silicone breast implants and/or polymer-based materials and breast cancer. In light of an initial report that 35% of rats implanted with a variety of polymers developed fibrosarcomas, we report a case of primary angiosarcoma found in a patient presenting with bilateral rupture of gel-filled breast implants.

Implantable Cardiac Pacemakers – 50 Years from the First Implantation

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Ratko Magjarević

2010-01-01

Overview: Development of implantable cardiac pacemaker was enabled by another important invention, the silicon transistor. h ough the invention of suitable lithium cells as appropriate power supply was essential for prolongation of battery life cycle and for increased reliability of pacemakers, main milestones in the development were associated with technological breakthroughs in electronics: from transistors, which introduced such features as small size and low power consumption, to hybrid and integrated circuits, which enabled programmability, microprocessors, which added more options in programming (multiprogrammability, diagnostics and telemetry, and the ICT (information communication technology that enabled physicians remote access to patients and interrogation of their implantable devices. Conclusions: Implantable pacemakers are reliable devices indicated for a wide range of dif erent therapies of cardiac rhythm disorders and heart failure. h ere is still a lot to learn about the physiology of a normal heart and even more about the failing heart. Modern pacemakers provide physicians valuable information from pacemakers’ memory via the built-in telemetry system. h ese information help physicians to better understand pathologic processes within the heart, thus contributing to the development of new ideas for treatment of diseases and for precise tailoring of the therapy to the patient’s needs. Although implantable pacemakers have reached the level of mature technology, they will continue to develop with therapies and diagnostics to facilitate a higher quality of life.

Effect of Nanosheet Surface Structure of Titanium Alloys on Cell Differentiation

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Satoshi Komasa

2014-01-01

Full Text Available Titanium alloys are the most frequently used dental implants partly because of the protective oxide coating that spontaneously forms on their surface. We fabricated titania nanosheet (TNS structures on titanium surfaces by NaOH treatment to improve bone differentiation on titanium alloy implants. The cellular response to TNSs on Ti6Al4V alloy was investigated, and the ability of the modified surfaces to affect osteogenic differentiation of rat bone marrow cells and increase the success rate of titanium implants was evaluated. The nanoscale network structures formed by alkali etching markedly enhanced the functions of cell adhesion and osteogenesis-related gene expression of rat bone marrow cells. Other cell behaviors, such as proliferation, alkaline phosphatase activity, osteocalcin deposition, and mineralization, were also markedly increased in TNS-modified Ti6Al4V. Our results suggest that titanium implants modified with nanostructures promote osteogenic differentiation, which may improve the biointegration of these implants into the alveolar bone.

Implantable biochemical fuel cell

Energy Technology Data Exchange (ETDEWEB)

Richter, G; Rao, J R

1978-01-05

Implantable biochemical fuel cells for the operation of heart pacemakers or artificial hearts convert oxidisable body substances such as glucose on the anode side and reduce the oxygen contained in body fluids at the cathode. The anode and cathode are separated by membranes which are impermeable to albumen and blood corpuscles in body fluids. A chemical shortcircuit cannot occur in practice if, according to the invention, one or more selective oxygen electrodes with carbon as catalyst are arranged so that the mixture which diffuses into the cell from body fluids during operation reaches the fuel cell electrode through the porous oxygen electrode. The membranes used must be permeable to water. Cellulose, polymerised polyvinyl alcohol or an ion exchanger with a buffering capacity between pH5 and 8 act as permeable materials.

The effect of x-irradiation on the implantation and development of the white rat fetus

International Nuclear Information System (INIS)

Danius, J.; Bahauddin, R.

1976-01-01

X-ray whole body irradiation (200R, exposure dose) was performed on young virgin females of about 4 months old. The female rats, divided into three groups, were treated as follows: Female rats as control (unirradiated = 1Kt): female rats irradiated before mating (RSbK), and female rats irradiated after mating (RSsK). The average number of surviving foetuses at 20 days gestational stage of 1Kt was compared with that of RSbK, and no significant difference was found (P<=0.05) while the difference between the average number of RSsK foetuses compared with that of 1Kt and RSbK was highly significant (P<0.01). A decrease in the average number of surviving foetuses was found in RSsK, although the analysis of variance of all groups, revealed no significant difference (P<=0.05) in the average number of implantations and weight of the foetuses. (author)

Melatonin potentiates glycine currents through a PLC/PKC signalling pathway in rat retinal ganglion cells.

Science.gov (United States)

Zhao, Wen-Jie; Zhang, Min; Miao, Yanying; Yang, Xiong-Li; Wang, Zhongfeng

2010-07-15

In vertebrate retina, melatonin regulates various physiological functions. In this work we investigated the mechanisms underlying melatonin-induced potentiation of glycine currents in rat retinal ganglion cells (RGCs). Immunofluorescence double labelling showed that rat RGCs were solely immunoreactive to melatonin MT(2) receptors. Melatonin potentiated glycine currents of RGCs, which was reversed by the MT(2) receptor antagonist 4-P-PDOT. The melatonin effect was blocked by intracellular dialysis of GDP-beta-S. Either preincubation with pertussis toxin or application of the phosphatidylcholine (PC)-specific phospholipase C (PLC) inhibitor D609, but not the phosphatidylinositol (PI)-PLC inhibitor U73122, blocked the melatonin effect. The protein kinase C (PKC) activator PMA potentiated the glycine currents and in the presence of PMA melatonin failed to cause further potentiation of the currents, whereas application of the PKC inhibitor bisindolylmaleimide IV abolished the melatonin-induced potentiation. The melatonin effect persisted when [Ca(2+)](i) was chelated by BAPTA, and melatonin induced no increase in [Ca(2+)](i). Neither cAMP-PKA nor cGMP-PKG signalling pathways seemed to be involved because 8-Br-cAMP or 8-Br-cGMP failed to cause potentiation of the glycine currents and both the PKA inhibitor H-89 and the PKG inhibitor KT5823 did not block the melatonin-induced potentiation. In consequence, a distinct PC-PLC/PKC signalling pathway, following the activation of G(i/o)-coupled MT(2) receptors, is most likely responsible for the melatonin-induced potentiation of glycine currents of rat RGCs. Furthermore, in rat retinal slices melatonin potentiated light-evoked glycine receptor-mediated inhibitory postsynaptic currents in RGCs. These results suggest that melatonin, being at higher levels at night, may help animals to detect positive or negative contrast in night vision by modulating inhibitory signals largely mediated by glycinergic amacrine cells in the inner

Bacterial Biofilm Infection Detected in Breast Implant-Associated Anaplastic Large-Cell Lymphoma.

Science.gov (United States)

Hu, Honghua; Johani, Khalid; Almatroudi, Ahmad; Vickery, Karen; Van Natta, Bruce; Kadin, Marshall E; Brody, Garry; Clemens, Mark; Cheah, Chan Yoon; Lade, Stephen; Joshi, Preeti Avinash; Prince, H Miles; Deva, Anand K

2016-06-01

A recent association between breast implants and the development of anaplastic large-cell lymphoma (ALCL) has been observed. The purpose of this study was to identify whether bacterial biofilm is present in breast implant-associated ALCL and, if so, to compare the bacterial microbiome to nontumor capsule samples from breast implants with contracture. Twenty-six breast implant-associated ALCL samples were analyzed for the presence of biofilm by real-time quantitative polymerase chain reaction, next-generation sequencing, fluorescent in situ hybridization, and scanning electron microscopy, and compared to 62 nontumor capsule specimens. Both the breast implant-associated ALCL and nontumor capsule samples yielded high mean numbers of bacteria (breast implant-associated ALCL, 4.7 × 10 cells/mg of tissue; capsule, 4.9 × 10 cells/mg of tissue). Analysis of the microbiome in breast implant-associated ALCL specimens showed significant differences with species identified in nontumor capsule specimens. There was a significantly greater proportion of Ralstonia spp. present in ALCL specimens compared with nontumor capsule specimens (p capsule specimens compared with breast implant-associated ALCL specimens (p < 0.001). Bacterial biofilm was visualized both on scanning electron microscopy and fluorescent in situ hybridization. This novel finding of bacterial biofilm and a distinct microbiome in breast implant-associated ALCL samples points to a possible infectious contributing cause. Breast implants are widely used in both reconstructive and aesthetic surgery, and strategies to reduce their contamination should be more widely studied and practiced. Risk, V.

Ex vivo exposure of bone marrow from chronic kidney disease donor rats to pravastatin limits renal damage in recipient rats with chronic kidney disease

NARCIS (Netherlands)

Koppen, A. van; Papazova, D.A.; Oosterhuis, N.R.; Gremmels, H.; Giles, R.H.; Fledderus, J.O.; Joles, J.A.; Verhaar, M.C.

2015-01-01

Introduction: Healthy bone marrow cell (BMC) infusion improves renal function and limits renal injury in a model of chronic kidney disease (CKD) in rats. However, BMCs derived from rats with CKD fail to retain beneficial effects, demonstrating limited therapeutic efficacy. Statins have been reported

Ex vivo exposure of bone marrow from chronic kidney disease donor rats to pravastatin limits renal damage in recipient rats with chronic kidney disease

NARCIS (Netherlands)

van Koppen, Arianne; Papazova, Diana A.; Oosterhuis, Nynke R.; Gremmels, Hendrik; Giles, Rachel H.; Fledderus, Joost O.; Joles, Jaap A.; Verhaar, Marianne C.

2015-01-01

INTRODUCTION: Healthy bone marrow cell (BMC) infusion improves renal function and limits renal injury in a model of chronic kidney disease (CKD) in rats. However, BMCs derived from rats with CKD fail to retain beneficial effects, demonstrating limited therapeutic efficacy. Statins have been reported

Macrophages, Foreign Body Giant Cells and Their Response to Implantable Biomaterials

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Zeeshan Sheikh

2015-08-01

Full Text Available All biomaterials, when implanted in vivo, elicit cellular and tissue responses. These responses include the inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the implanted materials. Macrophages are myeloid immune cells that are tactically situated throughout the tissues, where they ingest and degrade dead cells and foreign materials in addition to orchestrating inflammatory processes. Macrophages and their fused morphologic variants, the multinucleated giant cells, which include the foreign body giant cells (FBGCs are the dominant early responders to biomaterial implantation and remain at biomaterial-tissue interfaces for the lifetime of the device. An essential aspect of macrophage function in the body is to mediate degradation of bio-resorbable materials including bone through extracellular degradation and phagocytosis. Biomaterial surface properties play a crucial role in modulating the foreign body reaction in the first couple of weeks following implantation. The foreign body reaction may impact biocompatibility of implantation devices and may considerably impact short- and long-term success in tissue engineering and regenerative medicine, necessitating a clear understanding of the foreign body reaction to different implantation materials. The focus of this review article is on the interactions of macrophages and foreign body giant cells with biomaterial surfaces, and the physical, chemical and morphological characteristics of biomaterial surfaces that play a role in regulating the foreign body response. Events in the foreign body response include protein adsorption, adhesion of monocytes/macrophages, fusion to form FBGCs, and the consequent modification of the biomaterial surface. The effect of physico-chemical cues on macrophages is not well known and there is a complex interplay between biomaterial properties and those that result from interactions with the local environment. By having a

Functional assessment of hepatocytes after transplantation into rat spleen

International Nuclear Information System (INIS)

Woods, R.J.; Fuller, B.J.; Attenburrow, V.D.; Nutt, L.H.; Hobbs, K.E.

1982-01-01

The retention of structural integrity and metabolic function by isolated hepatocytes after ectopic transplantation has been investigated in autografted rats. Rats were partially hepatectomized and isolated hepatocytes prepared from the excised liver lobes were implanted into their spleens. Histological examination of the spleens 7 or more weeks after implantation revealed aggregates of hepatocytes in the red pulp. Two tests of biochemical function were applied to the hepatocytes after transplantation. In the first the hepatobiliary imaging agent technetium-99m N-[N'-(2, 6-dimethylphenyl)carbamoylmethyl]iminodiacetic acid (99mTc HIDA), which was shown to be avidly taken up by isolated hepatocytes in vitro, was infused into the tail veins of autograft and control rats. Radioactivity accumulating in the spleens of autografted rats was markedly greater than that in controls implanted with lethally damaged cells or in nontransplanted rats. In the second the presence of bilirubin metabolites was sought in autograft spleens after intravenous infusion of bilirubin. Both mono- and diglucuronides of bilirubin were recovered from the spleens of autograft rats but no conjugates were recovered from the spleens of unoperated controls. We conclude that after autotransplantation isolated hepatocytes retain their morphology and at least some of their functional activities

The Effect of Ag and Ag+N Ion Implantation on Cell Attachment Properties

International Nuclear Information System (INIS)

Urkac, Emel Sokullu; Oztarhan, Ahmet; Gurhan, Ismet Deliloglu; Iz, Sultan Gulce; Tihminlioglu, Funda; Oks, Efim; Nikolaev, Alexey; Ila, Daryush

2009-01-01

Implanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and Ag+N ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with model cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and Ag+N ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that Ag+N ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.

Effect of low-energy hydrogen ion implantation on dendritic web silicon solar cells

Science.gov (United States)

Rohatgi, A.; Meier, D. L.; Rai-Choudhury, P.; Fonash, S. J.; Singh, R.

1986-01-01

The effect of a low-energy (0.4 keV), short-time (2-min), heavy-dose (10 to the 18th/sq cm) hydrogen ion implant on dendritic web silicon solar cells and material was investigated. Such an implant was observed to improve the cell open-circuit voltage and short-circuit current appreciably for a number of cells. In spite of the low implant energy, measurements of internal quantum efficiency indicate that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. This is supported by the observation that the measured minority-carrier diffusion length in the base did not change when the emitter was removed. In some cases, a threefold increase of the base diffusion length was observed after implantation. The effects of the hydrogen implantation were not changed by a thermal stress test at 250 C for 111 h in nitrogen. It is speculated that hydrogen enters the bulk by traveling along dislocations, as proposed recently for edge-defined film-fed growth silicon ribbon.

Glioblastoma Stem Cells Respond to Differentiation Cues but Fail to Undergo Commitment and Terminal Cell-Cycle Arrest

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Helena Carén

2015-11-01

Full Text Available Glioblastoma (GBM is an aggressive brain tumor whose growth is driven by stem cell-like cells. BMP signaling triggers cell-cycle exit and differentiation of GBM stem cells (GSCs and, therefore, might have therapeutic value. However, the epigenetic mechanisms that accompany differentiation remain poorly defined. It is also unclear whether cell-cycle arrest is terminal. Here we find only a subset of GSC cultures exhibit astrocyte differentiation in response to BMP. Although overtly differentiated non-cycling astrocytes are generated, they remain vulnerable to cell-cycle re-entry and fail to appropriately reconfigure DNA methylation patterns. Chromatin accessibility mapping identified loci that failed to alter in response to BMP and these were enriched in SOX transcription factor-binding motifs. SOX transcription factors, therefore, may limit differentiation commitment. A similar propensity for cell-cycle re-entry and de-differentiation was observed in GSC-derived oligodendrocyte-like cells. These findings highlight significant obstacles to BMP-induced differentiation as therapy for GBM.

Homojunction silicon solar cells doping by ion implantation

Science.gov (United States)

Milési, Frédéric; Coig, Marianne; Lerat, Jean-François; Desrues, Thibaut; Le Perchec, Jérôme; Lanterne, Adeline; Lachal, Laurent; Mazen, Frédéric

2017-10-01

Production costs and energy efficiency are the main priorities for the photovoltaic (PV) industry (COP21 conclusions). To lower costs and increase efficiency, we are proposing to reduce the number of processing steps involved in the manufacture of N-type Passivated Rear Totally Diffused (PERT) silicon solar cells. Replacing the conventional thermal diffusion doping steps by ion implantation followed by thermal annealing allows reducing the number of steps from 7 to 3 while maintaining similar efficiency. This alternative approach was investigated in the present work. Beamline and plasma immersion ion implantation (BLII and PIII) methods were used to insert n-(phosphorus) and p-type (boron) dopants into the Si substrate. With higher throughput and lower costs, PIII is a better candidate for the photovoltaic industry, compared to BL. However, the optimization of the plasma conditions is demanding and more complex than the beamline approach. Subsequent annealing was performed on selected samples to activate the dopants on both sides of the solar cell. Two annealing methods were investigated: soak and spike thermal annealing. Best performing solar cells, showing a PV efficiency of about 20%, was obtained using spike annealing with adapted ion implantation conditions.

Characterization of poly (L-co-D,L Lactic Acid and a study of polymer-tissue interaction in subcutaneous implants in wistar rats

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Giuliano Serafino Ciambelli

2012-01-01

Full Text Available Poly (L-co-D,L lactic acid (PLDLA is an important biomaterial because of its biocompatibility properties that promote cellular regeneration and growth. The aim of this study was to evaluate the polymer-tissue interaction of PLDLA implants in the dorsal subcutaneous tissue of male Wistar rats at various intervals (2, 7, 15, 30, 60 and 90 days after implantation. Physical properties such as the glass transition point (Tg, degradation behavior and other mechanical properties were characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, gel permeation chromatography (GPC, scanning electron microscopy (SEM and tension tests. Analysis of the degradation of PLDLA membranes in vitro showed that the polymer became crystalline as a function of the degradation time. Mechanical tension tests showed that the polymer behaved like a ductile material: when subjected to constant tension it initially suffered deformation, then elongation and finally ruptured. TGA/MEV provided evidence of PLDLA membrane degradation. For histological analysis, samples from each group were processed in xylol/paraffin, except for the 60 - and 90 - day samples. Each of the latter samples was divided in two: one half was treated with xylol/paraffin and the other with historesin. Light microscopy showed the adhesion of cells to the biomaterial, the formation of a conjunctive capsule around the implant, the presence of epithelioid cells, the formation of foreign body giant cells and angiogenesis. During degradation, the polymer showed a 'lace' - like appearance when processed in xylol/paraffin compared to the formation of "centripetal cracks in the form of glove fingers" when embedded in historesin.

Long-term neuroplasticity of the face primary motor cortex and adjacent somatosensory cortex induced by tooth loss can be reversed following dental implant replacement in rats.

Science.gov (United States)

Avivi-Arber, Limor; Lee, Jye-Chang; Sood, Mandeep; Lakschevitz, Flavia; Fung, Michelle; Barashi-Gozal, Maayan; Glogauer, Michael; Sessle, Barry J

2015-11-01

Tooth loss is common, and exploring the neuroplastic capacity of the face primary motor cortex (face-M1) and adjacent primary somatosensory cortex (face-S1) is crucial for understanding how subjects adapt to tooth loss and their prosthetic replacement. The aim was to test if functional reorganization of jaw and tongue motor representations in the rat face-M1 and face-S1 occurs following tooth extraction, and if subsequent dental implant placement can reverse this neuroplasticity. Rats (n = 22) had the right maxillary molar teeth extracted under local and general anesthesia. One month later, seven rats had dental implant placement into healed extraction sites. Naive rats (n = 8) received no surgical treatment. Intracortical microstimulation (ICMS) and recording of evoked jaw and tongue electromyographic responses were used to define jaw and tongue motor representations at 1 month (n = 8) or 2 months (n = 7) postextraction, 1 month postimplant placement, and at 1-2 months in naive rats. There were no significant differences across study groups in the onset latencies of the ICMS-evoked responses (P > 0.05), but in comparison with naive rats, tooth extraction caused a significant (P rats. These novel findings suggest that face-M1 and adjacent face-S1 may play a role in adaptive mechanisms related to tooth loss and their replacement with dental implants. © 2015 Wiley Periodicals, Inc.

Uptake of 153Sm-DTPA-bis-biotin and 99mTc-DTPA-bis-biotin in rat as-30D-hepatoma cells

International Nuclear Information System (INIS)

Correa-Gonzalez, Luis; Arteaga de Murphy, Consuelo; Ferro-Flores, Guillermina; Pedraza-Lopez, Martha; Murphy-Stack, Eduardo; Mino-Leon, Dolores; Perez-Villasenor, Graciela; Diaz-Torres, Yaneth; Munoz-Olvera, Rodrigo

2003-01-01

Labeled biotin has been used mainly for pretargeted therapy, an approach for increasing the amount of radioactivity delivered to a cancer cell. The aim of this investigation was to prepare 153 Sm-DTPA-bis-biotin and 99m Tc-DTPA-bis-biotin in order to study their in vitro and in vivo uptake in rat AS-30D hepatoma cells found in ascites and in implanted tumor. DTPA-bis-biotin (pH 8) was 153 Sm labeled with 153 SmCl 3 and 99m Tc-DTPA-bis-biotin was prepared via SnCl 2 reduction. Radiochemical purity was >98% in both cases. AS-30D hepatoma cells were obtained from ascites of a rat with hepatoma and were propagated in the peritoneum cavity of normal rats. In vitro ascites cell 153 Sm-DTPA-bis-biotin uptake was compared with 153 SmCl 3 cell uptake. The ratio cell 153 Sm-DTPA-bis-biotin/ 153 SmCl 3 was 39.6 and when avidin was added it increased to 50. The ratio 99m Tc-DTPA-bis-biotin/TcO 4 Na was 8.7. Concentration of 153 Sm-DTPA-bis-biotin in tumor 2, 3 and 24 h after administration, was 5, 15 and 3 times higher than in normal muscle (T/nT). Biodistribution in a 0.083-24 h time period showed that 153 Sm-DTPA-bis-biotin was taken up only by ascites tumor cells and hepatoma cells. Two and 3 h ratio ascites/liver (As/Lv) was 6.4 and 6.0. For 99m Tc-DTPA-bis-biotin 2 and 3 h T/nT was 15.7 and 4.7 and 2 h As/Lv was 1.4. In conclusion, both radiopharmaceuticals show high uptake in rat AS-30D hepatoma cells in ascites and in implanted tumor. Since lung, thyroid, kidney, liver or pancreas carcinomas are ascites producing cancers 153 Sm-DTPA-bis-biotin would be an adequate therapeutic radiopharmaceutical for these patients whose life quality would be enhanced with control of ascites, and a reduction of the primary tumor and its metastases

Use of subconjunctival injections of 5-fluorouracil to rescue and prolong intraocular pressure reduction for a failing Ahmed glaucoma implant.

Science.gov (United States)

Kaplowitz, Kevin; Khodadadeh, Sarah; Wang, Samantha; Lee, Daniel; Tsai, James C

2017-06-01

5-Fluorouracil (5-FU) has been well described for a failing trabeculectomy bleb, but not for aqueous shunts. We sought to determine whether subconjunctival 5-FU prolongs the intraocular pressure (IOP) efficacy of Ahmed shunts. We included all patients with Ahmed FP-7 implantation by one surgeon at Yale University. Patients with  21 on >2 medications. Five-milligram (0.1 cc) injections were made over the plate. The control group consisted of Ahmed FP-7 patients without injections. The main outcome measure was IOP. Secondary outcome was success (IOP Ahmed shunts. Outcomes between eyes receiving injections and controls were statistically similar.

An automated ion implant/pulse anneal machine for low cost silicon cell production

International Nuclear Information System (INIS)

Armini, A.J.; Bunker, S.N.; Spitzer, M.B.

1982-01-01

The continuing development of a high throughput ion implanter and a pulsed electron beam annealer designed for dedicated silicon solar cell manufacture is reviewed. This equipment is intended for production of junctions in 10 cm wide wafers at a throughput up to 10 MWsub(p) per year. The principal features of the implanter are the lack of mass analysis and defocusing utilizing electrostatic deflection. The implanted surface is annealed by liquid phase epitaxy resulting from a single burst of a large area electron beam. Cells with non-mass analyzed ion implantation have yielded AM1 cell efficiencies in excess of 15%. Pulse annealed Czochralski cells have been made with AM1 efficiencies of 13% vs. 15% for a furnace annealed group. Results of pulse annealing of polycrystalline materials indicate that cell performance comparable to diffusion can be obtained. (Auth.)

Recruitment of host's progenitor cells to sites of human amniotic fluid stem cells implantation.

Science.gov (United States)

Mirabella, Teodelinda; Poggi, Alessandro; Scaranari, Monica; Mogni, Massimo; Lituania, Mario; Baldo, Chiara; Cancedda, Ranieri; Gentili, Chiara

2011-06-01

The amniotic fluid is a new source of multipotent stem cells with a therapeutic potential for human diseases. Cultured at low cell density, human amniotic fluid stem cells (hAFSCs) were still able to generate colony-forming unit-fibroblast (CFU-F) after 60 doublings, thus confirming their staminal nature. Moreover, after extensive in vitro cell expansion hAFSCs maintained a stable karyotype. The expression of genes, such as SSEA-4, SOX2 and OCT3/4 was confirmed at early and later culture stage. Also, hAFSCs showed bright expression of mesenchymal lineage markers and immunoregulatory properties. hAFSCs, seeded onto hydroxyapatite scaffolds and subcutaneously implanted in nude mice, played a pivotal role in mounting a response resulting in the recruitment of host's progenitor cells forming tissues of mesodermal origin such as fat, muscle, fibrous tissue and immature bone. Implanted hAFSCs migrated from the scaffold to the skin overlying implant site but not to other organs. Given their in vivo: (i) recruitment of host progenitor cells, (ii) homing towards injured sites and (iii) multipotentiality in tissue repair, hAFSCs are a very appealing reserve of stem cells potentially useful for clinical application in regenerative medicine. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influence of Piezosurgery on Bone Healing around Titanium Implants: A Histological Study in Rats.

Science.gov (United States)

Sirolli, Marcelo; Mafra, Carlos Eduardo Secco; Santos, Rodrigo Albuquerque Basílio Dos; Saraiva, Luciana; Holzhausen, Marinella; César, João Batista

2016-01-01

The aim of this study was to evaluate histomorphometrically the influence of two techniques of dental implant site preparation on bone healing around titanium implants. Fifteen male Wistar rats (±300 g) were used in the study. Each tibia was randomly assigned to receive the implant site preparation either with a conventional drilling technique (control - DRILL group) or with a piezoelectric device (PIEZO group). The animals were sacrificed after 30 days and then the following histomorphometric parameters were evaluated (percentage) separately for cortical and cancellous regions: proportion of mineralized tissue (PMT) adjacent to implant threads (500 μm adjacent); bone area within the threads (BA) and bone-implant contact (BIC). The results demonstrated that there were no statistically significant differences between both groups for cancellous BIC (p>0.05) and cortical PMT (p>0.05). On the other hand, a higher percentage of BA was observed in the PIEZO group in the cortical (71.50±6.91 and 78.28±4.38 for DRILL and PIEZO groups, respectively; ppiezosurgery also showed higher PMT values in the cancellous zone (9.35±5.54 and 18.72±13.21 for DRILL and PIEZO groups, respectively; ppiezosurgery was beneficial to bone healing rates in the cancellous bone region, while the drill technique produced better results in the cortical bone.

High energy ion implantation

International Nuclear Information System (INIS)

Ziegler, J.F.

1985-01-01

High energy ion implantation offers the oppertunity for unique structures in semiconductor processing. The unusual physical properties of such implantations are discussed as well as the special problems in masking and damage annealing. A review is made of proposed circuit structures which involve deep implantation. Examples are: deep buried bipolar collectors fabricated without epitaxy, barrier layers to reduce FET memory sensitivity to soft-fails, CMOS isolation well structures, MeV implantation for customization and correction of completed circuits, and graded reach-throughs to deep active device components. (orig.)

RTV silicone rubber surface modification for cell biocompatibility by negative-ion implantation

International Nuclear Information System (INIS)

Zheng, Chenlong; Wang, Guangfu; Chu, Yingjie; Xu, Ya; Qiu, Menglin; Xu, Mi

2016-01-01

Highlights: • The radiation effect has a greater influence than doping effect on the hydrophilicity of RTV SR. • The implanted ions result in a new surface atomic bonding state and morphology. • Generating hydrophilic functional groups is a reason for the improved cell biocompatibility. • The micro roughness makes the hydrophilicity should be reduced due to the lotus effect. • Cell culture demonstrates that negative-ion implantation can improve biocompatibility. - Abstract: A negative cluster ion implantation system was built on the injector of a GIC4117 tandem accelerator. Next, the system was used to study the surface modification of room temperature vulcanization silicone rubber (RTV SR) for cell biocompatibility. The water contact angle was observed to decrease from 117.6° to 99.3° as the C_1"− implantation dose was increased to 1 × 10"1"6 ions/cm"2, and the effects of C_1"−, C_2"− and O_1"− implantation result in only small differences in the water contact angle at 3 × 10"1"5 ions/cm"2. These findings indicate that the hydrophilicity of RTV SR improves as the dose is increased and that the radiation effect has a greater influence than the doping effect on the hydrophilicity. There are two factors influence hydrophilicity of RTV: (1) based on the XPS and ATR-FTIR results, it can be inferred that ion implantation breaks the hydrophobic functional groups (Si−CH_3, Si−O−Si, C−H) of RTV SR and generates hydrophilic functional groups (−COOH, −OH, Si−(O)_x (x = 3,4)). (2) SEM reveals that the implanted surface of RTV SR appears the micro roughness such as cracks and wrinkles. The hydrophilicity should be reduced due to the lotus effect (Zhou Rui et al., 2009). These two factors cancel each other out and make the C-implantation sample becomes more hydrophilic in general terms. Finally, cell culture demonstrates that negative ion-implantation is an effective method to improve the cell biocompatibility of RTV SR.

Morphology and Differentiation of MG63 Osteoblast Cells on Saliva Contaminated Implant Surfaces

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Neda Shams

2015-11-01

Full Text Available Objectives: Osteoblasts are the most important cells in the osseointegration process. Despite years of study on dental Implants, limited studies have discussed the effect of saliva on the adhesion process of osteoblasts to implant surfaces. The aim of this in vitro study was to evaluate the effect of saliva on morphology and differentiation of osteoblasts attached to implant surfaces.Materials and Methods: Twelve Axiom dental implants were divided into two groups. Implants of the case group were placed in containers, containing saliva, for 40 minutes. Then, all the implants were separately stored in a medium containing MG63 human osteoblasts for a week. Cell morphology and differentiation were assessed using a scanning electron microscope and their alkaline phosphatase (ALP activity was determined. The t-test was used to compare the two groups.Results: Scanning electron microscopic observation of osteoblasts revealed round or square cells with fewer and shorter cellular processes in saliva contaminated samples, whereas elongated, fusiform and well-defined cell processes were seen in the control group. ALP level was significantly lower in case compared to control group (P<0.05.Conclusion: Saliva contamination alters osteoblast morphology and differentiation and may subsequently interfere with successful osseointegration. Thus, saliva contamination of bone and implant must be prevented or minimized.

Influence of metals on cytokines production in connection with successful implantation therapy in dentistry.

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Podzimek, Stepan; Tomka, Milan; Nemeth, Tibor; Himmlova, Lucie; Matucha, Petr; Prochazkova, Jarmila

2010-01-01

In most of patients in need of implantation treatment in the oral cavity, implants heal well, nevertheless, there are some individuals, in whom titanium implants fail for reasons, which remain unclear. The aim of our study was to determine if there is a difference between metal influenced IL-1β, IL-4, IL-6, TNF-α and IFN-γ cytokines production in patients with successfully healed implants compared to those, whose implant therapy was unsuccessful. The two study groups included 12 patients with failed dental titanium implants and 9 patients with successfully healed implants. In the subjects, cytokine production was established after lymphocyte cultivation with mercury, nickel and titanium antigens. IL-1β levels were significantly increased in all patients after stimulation with titanium and in patients with accepted implants compared to patients with failed implants after the stimulation with mercury and titanium. Titanium caused significantly increased IL-6 production in all patients. TNF-α and IFN-γ levels were also significantly increased after the stimulation with titanium. Significantly increased TNF-α levels were found in patients with accepted implants as compared to patients with failed implants. Increased production of IL-1β a IL-6 cytokines in reaction to titanium and increased production of TNF-α and IFN-γ cytokines in reaction to mercury, which is very often present in the form of amalgam in the oral cavity of persons in need of implant therapy, can play an important role in immune reactions during implant healing process. In patients with failed titanium implants, decreased production of these cytokines may participate in implant failure.

Composition and function of macroencapsulated human embryonic stem cell-derived implants: comparison with clinical human islet cell grafts.

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Motté, Evi; Szepessy, Edit; Suenens, Krista; Stangé, Geert; Bomans, Myriam; Jacobs-Tulleneers-Thevissen, Daniel; Ling, Zhidong; Kroon, Evert; Pipeleers, Daniel

2014-11-01

β-Cells generated from large-scale sources can overcome current shortages in clinical islet cell grafts provided that they adequately respond to metabolic variations. Pancreatic (non)endocrine cells can develop from human embryonic stem (huES) cells following in vitro derivation to pancreatic endoderm (PE) that is subsequently implanted in immune-incompetent mice for further differentiation. Encapsulation of PE increases the proportion of endocrine cells in subcutaneous implants, with enrichment in β-cells when they are placed in TheraCyte-macrodevices and predominantly α-cells when they are alginate-microencapsulated. At posttransplant (PT) weeks 20-30, macroencapsulated huES implants presented higher glucose-responsive plasma C-peptide levels and a lower proinsulin-over-C-peptide ratio than human islet cell implants under the kidney capsule. Their ex vivo analysis showed the presence of single-hormone-positive α- and β-cells that exhibited rapid secretory responses to increasing and decreasing glucose concentrations, similar to isolated human islet cells. However, their insulin secretory amplitude was lower, which was attributed in part to a lower cellular hormone content; it was associated with a lower glucose-induced insulin biosynthesis, but not with lower glucagon-induced stimulation, which together is compatible with an immature functional state of the huES-derived β-cells at PT weeks 20-30. These data support the therapeutic potential of macroencapsulated huES implants but indicate the need for further functional analysis. Their comparison with clinical-grade human islet cell grafts sets references for future development and clinical translation. Copyright © 2014 the American Physiological Society.

Ultrasonic implant site preparation using piezosurgery: a multicenter case series study analyzing 3,579 implants with a 1- to 3-year follow-up.

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Vercellotti, Tomaso; Stacchi, Claudio; Russo, Crescenzo; Rebaudi, Alberto; Vincenzi, Giampaolo; Pratella, Umberto; Baldi, Domenico; Mozzati, Marco; Monagheddu, Chiara; Sentineri, Rosario; Cuneo, Tommaso; Di Alberti, Luca; Carossa, Stefano; Schierano, Gianmario

2014-01-01

This multicenter case series introduces an innovative ultrasonic implant site preparation (UISP) technique as an alternative to the use of traditional rotary instruments. A total of 3,579 implants were inserted in 1,885 subjects, and the sites were prepared using a specific ultrasonic device with a 1- to 3-year follow-up. No surgical complications related to the UISP protocol were reported for any of the implant sites. Seventy-eight implants (59 maxillary, 19 mandibular) failed within 5 months of insertion, for an overall osseointegration percentage of 97.82% (97.14% maxilla, 98.75% mandible). Three maxillary implants failed after 3 years of loading, with an overall implant survival rate of 97.74% (96.99% maxilla, 98.75% mandible).

PINCH1 regulates cell-matrix and cell-cell adhesions, cell polarity and cell survival during the peri-implantation stage

DEFF Research Database (Denmark)

Li, Shaohua; Bordoy, Randi; Stanchi, Fabio

2005-01-01

PINCH1 is composed of 5 LIM domains, binds integrin-linked kinase (ILK) and locates to integrin-mediated adhesion sites. In order to investigate PINCH1 function we generated mice and embryonic stem (ES) cell-derived embryoid bodies (EBs) lacking the PINCH1 gene. Similar to mice lacking beta1...... integrin or Ilk, loss of PINCH1 arrested development at the peri-implantation stage. In contrast to beta1 integrin or Ilk mutants, however, disruption of the PINCH1 gene produced implantation chambers with visible cell clumps even at embryonic day 9.5. In order to define the phenotype leading to the peri...... not observed in beta1 integrin- or ILK-deficient mice or EBs, included abnormal cell-cell adhesion of endoderm and epiblast as well as the presence of apoptotic cells in the endodermal cell layer. Although ILK and PINCH1 were shown to be involved in the phosphorylation of serine-473 of PKB/Akt, immunostaining...

Peri-Implant Crestal Bone Loss: A Putative Mechanism

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Yuko Ujiie

2012-01-01

Full Text Available Purpose. The immunological mechanisms of peri-implant crestal bone loss have, hitherto, not been elucidated. We hypothesized that bacterial products from the microgap cause upregulation of cytokines in otherwise healthy peri-implant cells, which results in osteoclast formation and, ultimately, in bone resorption. Materials and Methods. We used RT-PCR and ELISA to assay mediators of osteoclastogenesis in rat and human macrophages (r-and hMO; bone marrow derived stromal cells (r-and hBMCs; and human gingival fibroblasts (hGF—with or without stimulation by LPS. TRAP positive multinucleate cells were assessed for their resorptive ability. Results. We show that IL-1α, IL-1β, and IL-6 were expressed by all examined cell types, and TNF-α was upregulated in hGF. Secretion of IL-1α and IL-1β proteins was stimulated in hMO by LPS, and IL-6 protein secretion was highly stimulated in hBMCs and hGF. Both LPS and RANKL stimulated macrophages to form osteoclast-like TRAP positive cells, which resorbed calcium phosphate substrates. Conclusion. Taken together, the results of our study support the hypothesis that bacterial endotoxins upregulate enhanced mediators of osteoclastogenesis in resident cells found in the healthy peri-implant compartment and that the local synergistic action of cytokines secreted by such cells results in the genesis of resorptively active osteoclasts.

Histatin 1 Enhances Cell Adhesion to Titanium in an Implant Integration Model.

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van Dijk, I A; Beker, A F; Jellema, W; Nazmi, K; Wu, G; Wismeijer, D; Krawczyk, P M; Bolscher, J G M; Veerman, E C I; Stap, J

2017-04-01

Cellular adhesion is essential for successful integration of dental implants. Rapid soft tissue integration is important to create a seal around the implant and prevent infections, which commonly cause implant failure and can result in bone loss. In addition, soft tissue management is important to obtain good dental aesthetics. We previously demonstrated that the salivary peptide histatin 1 (Hst1) causes a more than 2-fold increase in the ability of human adherent cells to attach and spread on a glass surface. Cells treated with Hst1 attached more rapidly and firmly to the substrate and to each other. In the current study, we examine the potential application of Hst1 for promotion of dental implant integration. Our results show that Hst1 enhances the attachment and spreading of soft tissue cell types (oral epithelial cells and fibroblasts) to titanium (Ti) and hydroxyapatite (HAP), biomaterials that have found wide applications as implant material in dentistry and orthopedics. For improved visualization of cell adhesion to Ti, we developed a novel technique that uses sputtering to deposit a thin, transparent layer of Ti onto glass slides. This approach allows detailed, high-resolution analysis of cell adherence to Ti in real time. Furthermore, our results suggest that Hst1 has no negative effects on cell survival. Given its natural occurrence in the oral cavity, Hst1 could be an attractive agent for clinical application. Importantly, even though Hst1 is specific for saliva of humans and higher primates, it stimulated the attachment and spreading of canine cells, paving the way for preclinical studies in canine models.

Repair of spinal cord injury by implantation of bFGF-incorporated HEMA-MOETACL hydrogel in rats

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Chen, Bo; He, Jianyu; Yang, Hao; Zhang, Qian; Zhang, Lingling; Zhang, Xian; Xie, En; Liu, Cuicui; Zhang, Rui; Wang, Yi; Huang, Linhong; Hao, Dingjun

2015-03-01

There is no effective strategy for the treatment of spinal cord injury (SCI). An appropriate combination of hydrogel materials and neurotrophic factor therapy is currently thought to be a promising approach. In this study, we performed experiments to evaluate the synergic effect of implanting hydroxyl ethyl methacrylate [2-(methacryloyloxy)ethyl] trimethylammonium chloride (HEMA-MOETACL) hydrogel incorporated with basic fibroblast growth factor (bFGF) into the site of surgically induced SCI. Prior to implantation, the combined hydrogel was surrounded by an acellular vascular matrix. Sprague-Dawley rats underwent complete spinal cord transection at the T-9 level, followed by implantation of bFGF/HEMA-MOETACL 5 days after transection surgery. Our results showed that the bFGF/HEMA-MOETACL transplant provided a scaffold for the ingrowth of regenerating tissue eight weeks after implantation. Furthermore, this newly designed implant promoted both nerve tissue regeneration and functional recovery following SCI. These results indicate that HEMA-MOETACL hydrogel is a promising scaffold for intrathecal, localized and sustained delivery of bFGF to the injured spinal cord and provide evidence for the possibility that this approach may have clinical applications in the treatment of SCI.

Silicon-Doped Titanium Dioxide Nanotubes Promoted Bone Formation on Titanium Implants.

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Zhao, Xijiang; Wang, Tao; Qian, Shi; Liu, Xuanyong; Sun, Junying; Li, Bin

2016-02-26

While titanium (Ti) implants have been extensively used in orthopaedic and dental applications, the intrinsic bioinertness of untreated Ti surface usually results in insufficient osseointegration irrespective of the excellent biocompatibility and mechanical properties of it. In this study, we prepared surface modified Ti substrates in which silicon (Si) was doped into the titanium dioxide (TiO₂) nanotubes on Ti surface using plasma immersion ion implantation (PIII) technology. Compared to TiO₂ nanotubes and Ti alone, Si-doped TiO₂ nanotubes significantly enhanced the expression of genes related to osteogenic differentiation, including Col-I, ALP, Runx2, OCN, and OPN, in mouse pre-osteoblastic MC3T3-E1 cells and deposition of mineral matrix. In vivo, the pull-out mechanical tests after two weeks of implantation in rat femur showed that Si-doped TiO₂ nanotubes improved implant fixation strength by 18% and 54% compared to TiO₂-NT and Ti implants, respectively. Together, findings from this study indicate that Si-doped TiO₂ nanotubes promoted the osteogenic differentiation of osteoblastic cells and improved bone-Ti integration. Therefore, they may have considerable potential for the bioactive surface modification of Ti implants.

Chlorhexidine-releasing implant coating on intramedullary nail reduces infection in a rat model

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SM Shiels

2018-03-01

Full Text Available The use of internal intramedullary nails for long bone fracture fixation is a common practice among surgeons. Bacteria naturally attach to these devices, increasing the risk for wound infection, which can result in non- or malunion, additional surgical procedures and extended hospital stays. Intramedullary nail surface properties can be modified to reduce bacterial colonisation and potentially infectious complications. In the current study, a coating combining a non-fouling property with leaching chlorhexidine for orthopaedic implantation was tested. Coating stability and chlorhexidine release were evaluated in vitro. Using a rat model of intramedullary fixation and infection, the effect of the coating on microbial colonisation and fracture healing was evaluated in vivo by quantitative microbiology, micro-computed tomography, plain radiography, three-point bending and/or histology. Low dose systemic cefazolin was administered to increase the similarities to clinical practice, without overshadowing the effect of the anti-infective coating. When introduced into a contaminated wound, the non-fouling chlorhexidine-coated implant reduced the overall bacteria colonisation within the bone and on the implant, reduced the osteolysis and increased the radiographic union, confirming its potential for reducing complications in wounds at high risk of infection. However, when implanted into a sterile wound, non-union increased. Further studies are required to best optimise the anti-microbial effectiveness, while not sacrificing fracture union.

Study of wettability and cell viability of H implanted stainless steel

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Shafique, Muhammad Ahsan; Ahmad, Riaz; Rehman, Ihtesham Ur

2018-03-01

In the present work, the effect of hydrogen ion implantation on surface wettability and biocompatibility of stainless steel is investigated. Hydrogen ions are implanted in the near-surface of stainless steel to facilitate hydrogen bonding at different doses with constant energy of 500 KeV, which consequently improve the surface wettability. Treated and untreated sample are characterized for surface wettability, incubation of hydroxyapatite and cell viability. Contact angle (CA) study reveals that surface wettability increases with increasing H-ion dose. Raman spectroscopy shows that precipitation of hydroxyapatite over the surface increase with increasing dose of H-ions. Cell viability study using MTT assay describes improved cell viability in treated samples as compared to the untreated sample. It is found that low dose of H-ions is more effective for cell proliferation and the cell count decreases with increasing ion dose. Our study demonstrates that H ion implantation improves the surface wettability and biocompatibility of stainless steel.

Transplantation of mesenchymal stem cells overexpressing IL10 attenuates cardiac impairments in rats with myocardial infarction.

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Meng, Xin; Li, Jianping; Yu, Ming; Yang, Jian; Zheng, Minjuan; Zhang, Jinzhou; Sun, Chao; Liang, Hongliang; Liu, Liwen

2018-01-01

Mesenchymal stem cell (MSC) has been well known to exert therapeutic potential for patients with myocardial infarction (MI). In addition, interleukin-10 (IL10) could attenuate MI through suppressing inflammation. Thus, the combination of MSC implantation with IL10 delivery may extend health benefits to ameliorate cardiac injury after MI. Here we established overexpression of IL10 in bone marrow-derived MSC through adenoviral transduction. Cell viability, apoptosis, and IL10 secretion under ischemic challenge in vitro were examined. In addition, MSC was transplanted into the injured hearts in a rat model of MI. Four weeks after the MI induction, MI, cardiac functions, apoptotic cells, and inflammation cytokines were assessed. In response to in vitro oxygen-glucose deprivation (OGD), IL10 overexpression in MSC (Ad.IL10-MSC) enhanced cell viability, decreased apoptosis, and increased IL10 secretion. Consistently, the implantation of Ad.IL10-MSCs into MI animals resulted in more reductions in myocardial infarct size, cardiac impairment, and cell apoptosis, compared to the individual treatments of either MSC or IL10 administration. Moreover, the attenuation of both systemic and local inflammations was most prominent for Ad.IL10-MSC treatment. IL10 overexpression and MSC may exert a synergistic anti-inflammatory effect to alleviate cardiac injury after MI. © 2017 Wiley Periodicals, Inc.

Conduction of impulses by axons regenerated in a Schwann cell graft in the transected adult rat thoracic spinal cord.

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Pinzon, A; Calancie, B; Oudega, M; Noga, B R

2001-06-01

Central nervous system axons regenerate into a Schwann cell implant placed in the transected thoracic spinal cord of an adult rat. The present study was designed to test whether these regenerated axons are capable of conducting action potentials. Following the transection and removal of a 4- to 5-mm segment of the thoracic spinal cord (T8-T9), a polymer guidance channel filled with a mixture of adult rat Schwann cells and Matrigel was grafted into a 4- to 5-mm-long gap in the transected thoracic spinal cord. The two cut ends of the spinal cord were eased into the guidance channel openings. Transected control animals received a channel containing Matrigel only. Three months after implantation, electrophysiological studies were performed. Tungsten microelectrodes were used for monopolar stimulation of regenerated axons within the Schwann cell graft. Glass microelectrodes were used to record responses in the spinal cord rostral to the stimulation site. Evoked responses to electrical stimulation of the axon cable were found in two out of nine Schwann cell-grafted animals. These responses had approximate latencies in the range of those of myelinated axons. No responses were seen in any of the Matrigel-grafted animals. Histological analysis revealed that the two cases that showed evoked potentials had the largest number of myelinated axons present in the cable. This study demonstrates that axons regenerating through Schwann cell grafts in the complete transected spinal cord can produce measurable evoked responses following electrical stimulation. Copyright 2001 Wiley-Liss, Inc.

Magnetic stem cell targeting to the inner ear

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Le, T. N.; Straatman, L.; Yanai, A.; Rahmanian, R.; Garnis, C.; Häfeli, U. O.; Poblete, T.; Westerberg, B. D.; Gregory-Evans, K.

2017-12-01

Severe sensorineural deafness is often accompanied by a loss of auditory neurons in addition to injury of the cochlear epithelium and hair cell loss. Cochlear implant function however depends on a healthy complement of neurons and their preservation is vital in achieving optimal results. We have developed a technique to target mesenchymal stem cells (MSCs) to a deafened rat cochlea. We then assessed the neuroprotective effect of systematically delivered MSCs on the survival and function of spiral ganglion neurons (SGNs). MSCs were labeled with superparamagnetic nanoparticles, injected via the systemic circulation, and targeted using a magnetized cochlea implant and external magnet. Neurotrophic factor concentrations, survival of SGNs, and auditory function were assessed at 1 week and 4 weeks after treatments and compared against multiple control groups. Significant numbers of magnetically targeted MSCs (>30 MSCs/section) were present in the cochlea with accompanied elevation of brain-derived neurotrophic factor and glial cell-derived neurotrophic factor levels (p < 0.001). In addition we saw improved survival of SGNs (approximately 80% survival at 4 weeks). Hearing threshold levels in magnetically targeted rats were found to be significantly better than those of control rats (p < 0.05). These results indicate that magnetic targeting of MSCs to the cochlea can be accomplished with a magnetized cochlear permalloy implant and an external magnet. The targeted stem cells release neurotrophic factors which results in improved SGN survival and hearing recovery. Combining magnetic cell-based therapy and cochlear implantation may improve cochlear implant function in treating deafness.

Enhancement of Bone Marrow-Derived Mesenchymal Stem Cell Osteogenesis and New Bone Formation in Rats by Obtusilactone A

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Yi-Hsiung Lin

2017-11-01

Full Text Available The natural pure compound obtusilactone A (OA was identified in Cinnamomum kotoense Kanehira & Sasaki, and shows effective anti-cancer activity. We studied the effect of OA on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs. OA possesses biocompatibility, stimulates Alkaline Phosphatase (ALP activity and facilitates mineralization of BMSCs. Expression of osteogenesis markers BMP2, Runx2, Collagen I, and Osteocalcin was enhanced in OA-treated BMSCs. An in vivo rat model with local administration of OA via needle implantation to bone marrow-residing BMSCs revealed that OA increased the new bone formation and trabecular bone volume in tibias. Micro-CT images and H&E staining showed more trabecular bone at the needle-implanted site in the OA group than the normal saline group. Thus, OA confers an osteoinductive effect on BMSCs via induction of osteogenic marker gene expression, such as BMP2 and Runx2 expression and subsequently elevates ALP activity and mineralization, followed by enhanced trabecular bone formation in rat tibias. Therefore, OA is a potential osteoinductive drug to stimulate new bone formation by BMSCs.

Engineered Protein Coatings to Improve the Osseointegration of Dental and Orthopaedic Implants

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Raphel, Jordan; Karlsson, Johan; Galli, Silvia; Wennerberg, Ann; Lindsay, Christopher; Haugh, Matthew; Pajarinen, Jukka; Goodman, Stuart B.; Jimbo, Ryo; Andersson, Martin; Heilshorn, Sarah C.

2016-01-01

Here we present the design of an engineered, elastin-like protein (ELP) that is chemically modified to enable stable coatings on the surfaces of titanium-based dental and orthopaedic implants by novel photocrosslinking and solution processing steps. The ELP includes an extended RGD sequence to confer bio-signaling and an elastin-like sequence for mechanical stability. ELP thin films were fabricated on cp-Ti and Ti6Al4V surfaces using scalable spin and dip coating processes with photoactive covalent crosslinking through a carbene insertion mechanism. The coatings withstood procedures mimicking dental screw and hip replacement stem implantations, a key metric for clinical translation. They promoted rapid adhesion of MG63 osteoblast-like cells, with over 80% adhesion after 24 hours, compared to 38% adhesion on uncoated Ti6Al4V. MG63 cells produced significantly more mineralization on ELP coatings compared to uncoated Ti6Al4V. Human bone marrow mesenchymal stem cells (hMSCs) had an earlier increase in alkaline phosphatase activity, indicating more rapid osteogenic differentiation and mineral deposition on adhesive ELP coatings. Rat tibia and femur in vivo studies demonstrated that cell-adhesive ELP-coated implants increased bone-implant contact area and interfacial strength after one week. These results suggest that ELP coatings withstand surgical implantation and promote rapid osseointegration, enabling earlier implant loading and potentially preventing micromotion that leads to aseptic loosening and premature implant failure. PMID:26790146

Adenovirus type 5 induces progression of quiescent rat cells into S phase without polyamine accumulation.

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Cheetham, B F; Shaw, D C; Bellett, A J

1982-01-01

Adenovirus type 5 induces cellular DNA synthesis and thymidine kinase in quiescent rat cells but does not induce ornithine decarboxylase. We now show that unlike serum, adenovirus type 5 fails to induce S-adenosylmethionine decarboxylase or polyamine accumulation. The inhibition by methylglyoxal bis(guanylhydrazone) of the induction of thymidine kinase by adenovirus type 5 is probably unrelated to its effects on polyamine biosynthesis. Thus, induction of cellular thymidine kinase and DNA replication by adenovirus type 5 is uncoupled from polyamine accumulation. PMID:7177112

Future directions of failed implantation and recurrent miscarriage research

DEFF Research Database (Denmark)

Christiansen, Ole B; Nielsen, Henriette Svarre; Kolte, Astrid M

2006-01-01

Recurrent implantation failure is today the major reason for women completing several IVF/intracytoplasmic sperm injection attempts without having achieved a child, and is probably also the explanation for many cases of unexplained infertility. Most causes of recurrent miscarriage are still poorl...

In vivo autoradiographic demonstration of β-adrenergic binding sites in adult rat type II alveolar epithelial cells

International Nuclear Information System (INIS)

Smith, D.M.; Sidhu, M.K.

1984-01-01

Adult male rats were injected intravenously with the muscarinic binding probe 3 H-Quinuclidinyl benzilate (QNB) or the β-adrenergic probe 3 H-dihydroalprenolol (DHA). Other rats were pre-treated with an intraperitoneal injection of a 500-fold excess of L-isoproterenol prior to the DHA. Light microscopic autoradiography of 0.5 μm sections of lung from the QNB group demonstrated very little labelling even after 6 months of exposure. In constrast, trachealis smooth muscle from these animals contained substantial labelling. Autoradiographs of lung from rats injected with DHA demonstrated labelling which was well localized over alveolar septa and concentrated over the cytoplasm of type II cells. Quantitative analysis of labelling in the DHA groups indicated a significant reduction of labelling in animals treated with L-isoproterenol prior to DHA, in both the alveolar parenchyma in general and over type II cells. The results of this study provide morphologic evidence for the uptake and specific binding of β-adrenergic antagonists by the adult lung in vivo, while failing to demonstrate similar binding of a muscarinic probe. In addition, the results demonstrate specific β-adrenergic receptors on type II cells in vivo and substantiate the view of a direct effect of β-adrenergic agonists on alveolar type II cells

Interactions between endothelial progenitor cells (EPC) and titanium implant surfaces.

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Ziebart, Thomas; Schnell, Anne; Walter, Christian; Kämmerer, Peer W; Pabst, Andreas; Lehmann, Karl M; Ziebart, Johanna; Klein, Marc O; Al-Nawas, Bilal

2013-01-01

Endothelial cells play an important role in peri-implant angiogenesis during early bone formation. Therefore, interactions between endothelial progenitor cells (EPCs) and titanium dental implant surfaces are of crucial interest. The aim of our in vitro study was to investigate the reactions of EPCs in contact with different commercially available implant surfaces. EPCs from buffy coats were isolated by Ficoll density gradient separation. After cell differentiation, EPC were cultured for a period of 7 days on different titanium surfaces. The test surfaces varied in roughness and hydrophilicity: acid-etched (A), sand-blasted-blasted and acid-etched (SLA), hydrophilic A (modA), and hydrophilic SLA (modSLA). Plastic and fibronectin-coated plastic surfaces served as controls. Cell numbers and morphology were analyzed by confocal laser scanning microscopy. Secretion of vascular endothelial growth factor (VEGF)-A was measured by enzyme-linked immunosorbent assay and expressions of iNOS and eNOS were investigated by real-time polymerase chain reaction. Cell numbers were higher in the control groups compared to the cells of titanium surfaces. Initially, hydrophilic titanium surfaces (modA and modSLA) showed lower cell numbers than hydrophobic surfaces (A and SLA). After 7 days smoother surfaces (A and modA) showed increased cell numbers compared to rougher surfaces (SLA and modSLA). Cell morphology of A, modA, and control surfaces was characterized by a multitude of pseudopodia and planar cell soma architecture. SLA and modSLA promoted small and plump cell soma with little quantity of pseudopodia. The lowest VEGF level was measured on A, the highest on modSLA. The highest eNOS and iNOS expressions were found on modA surfaces. The results of this study demonstrate that biological behaviors of EPCs can be influenced by different surfaces. The modSLA surface promotes an undifferentiated phenotype of EPCs that has the ability to secrete growth factors in great quantities. In

Bone Cells Dynamics during Peri-Implantitis: a Theoretical Analysis

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Maria Helena Fernandes

2016-09-01

Full Text Available Objectives: The present manuscript aims a detailed characterization of the bone cells dynamics during physiological bone remodelling and, subsequently, to address the cellular and molecular mechanisms that play a fundamental role in the immune-inflammatory-induced uncoupled bone remodelling observed in peri-implantitis. Results: An intimate relationship between the immune system and bone is acknowledged to be determinant for bone tissue remodelling and integrity. Due to the close interaction of immune and bone cells, the two systems share a number of surface receptors, cytokines, signalling pathways and transcription factors that are involved in mutual regulatory mechanisms. This physiological equilibrium is disturbed in pathological conditions, as verified in peri-implantitis establishment and development. Activation of the innate and adaptive immune response, challenged by the local bacterial infection, induces the synthesis of high levels of a variety of pro- and anti-inflammatory cytokines that disturb the normal functioning of the bone cells, by uncoupling bone resorption and formation, ending up with a net alveolar bone loss and subsequent implant failure. Most data points to an immune-inflammatory induced osteoclast differentiation and function, as the major underlying mechanism to the uncoupled bone resorption to bone formation. Further, the disturbed functioning of osteoblasts, reflected by the possible expression of a fibro-osteoblastic phenotype, may also play a role. Conclusions: Alveolar bone loss is a hallmark of peri-implantitis. A great deal of data is still needed on the cellular and humoral crosstalk in the context of an integrated view of the osteoimmunologic interplay occurring in the peri-implantitis environment subjacent to the bone loss outcome.

Host inflammatory response to polypropylene implants: insights from a quantitative immunohistochemical and birefringence analysis in a rat subcutaneous model

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Alessandro Prudente

2016-06-01

Full Text Available ABSTRACT Objectives To describe acute and sub acute aspects of histological and immunohistochemical response to PP implant in a rat subcutaneous model based on objective methods. Materials and Methods Thirty rats had a PP mesh subcutaneously implanted and the same dissection on the other side of abdomen but without mesh (sham. The animals were euthanized after 4 and 30 days. Six slides were prepared using the tissue removed: one stained with hematoxylin-eosin (inflammation assessment; one unstained (birefringence evaluation and four slides for immunohistochemical processing: IL-1 and TNF-α (pro-inflammatory cytokines, MMP-2 (collagen metabolism and CD-31 (angiogenesis. The area of inflammation, the birefringence index, the area of immunoreactivity and the number of vessels were objectively measured. Results A larger area of inflammatory reaction was observed in PP compared to sham on the 4th and on the 30th day (p=0.0002. After 4 days, PP presented higher TNF (p=0.0001 immunoreactivity than sham and no differences were observed in MMP-2 (p=0.06 and IL-1 (p=0.08. After 30 days, a reduction of IL-1 (p=0.010 and TNF (p=0.016 for PP and of IL-1 (p=0.010 for sham were observed. Moreover, area of MMP-2 immunoreactivity decreased over time for PP group (p=0.018. Birefringence index and vessel counting showed no differences between PP and sham (p=0.27 and p=0.58, respectively. Conclusions The implantation of monofilament and macroporous polypropylene in the subcutaneous of rats resulted in increased inflammatory activity and higher TNF production in the early post implant phase. After 30 days, PP has similar cytokines immunoreactivity, vessel density and extracellular matrix organization.

Healing of experimental femoral defects in rats after implantation of collagen-calcium phosphate biocomposites

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O. V. Korenkov

2017-06-01

Full Text Available The aim of this study was to investigate the healing process of experimental defects of the femoral shaft diaphysis of rats after implantation of osteoplastic material Collapan into its cavity. In experi-mental animals, a perforated defect with diameter of 2.5 mm was created in the medullary canal of the femoral shaft and filled with osteoplastic material Collapan. In control rats, the defect was left un-filled. The bone fragments were examined on the 15th and 30th day by light microscopy morphometry and scanning electron microscopy. It was found that application of osteoplastic material Collapan in the femoral diaphysis defect optimised reparative osteogenesis, showed high biocompatibility, osteo-conductive properties, resorption ability and good integration with tissue-specific structures of the regenerate

Age-related changes in rat bone-marrow mesenchymal stem cell plasticity

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Chase P Bryant

2011-10-01

Full Text Available Abstract Background The efficacy of adult stem cells is known to be compromised as a function of age. This therefore raises questions about the effectiveness of autologous cell therapy in elderly patients. Results We demonstrated that the expression profile of stemness markers was altered in BM-MSCs derived from old rats. BM-MSCs from young rats (4 months expressed Oct-4, Sox-2 and NANOG, but we failed to detect Sox-2 and NANOG in BM-MSCs from older animals (15 months. Chondrogenic, osteogenic and adipogenic potential is compromised in old BM-MSCs. Stimulation with a cocktail mixture of bone morphogenetic protein (BMP-2, fibroblast growth factor (FGF-2 and insulin-like growth factor (IGF-1 induced cardiomyogenesis in young BM-MSCs but not old BM-MSCs. Significant differences in the expression of gap junction protein connexin-43 were observed between young and old BM-MSCs. Young and old BM-MSCs fused with neonatal ventricular cardiomyocytes in co-culture and expressed key cardiac transcription factors and structural proteins. Cells from old animals expressed significantly lower levels of VEGF, IGF, EGF, and G-CSF. Significantly higher levels of DNA double strand break marker γ-H2AX and diminished levels of telomerase activity were observed in old BM-MSCs. Conclusion The results suggest age related differences in the differentiation capacity of BM-MSCs. These changes may affect the efficacy of BM-MSCs for use in stem cell therapy.

Alveolar ridge augmentation in rats by combined hydroxylapatite and osteoinductive material

DEFF Research Database (Denmark)

Pinholt, E M; Bang, G; Haanaes, H R

1991-01-01

, lyophilized dentin or bone and implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles in rats. Light microscopic evaluation revealed that HA was surrounded by fibrous connective tissue containing foreign body giant cells and it had neither...... an osteoinductive nor an osteoconductive effect. The newly formed bone induced from the implanted allogenic, demineralized, lyophilized dentin or bone was never found in close contact with the HA and did not incorporate the implant....

RTV silicone rubber surface modification for cell biocompatibility by negative-ion implantation

Energy Technology Data Exchange (ETDEWEB)

Zheng, Chenlong [Key Laboratory of Beam Technology and Material Modification Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, 100875 Beijing (China); Wang, Guangfu, E-mail: 88088@bnu.edu.cn [Key Laboratory of Beam Technology and Material Modification Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, 100875 Beijing (China); Beijing Radiation Center, 100875 Beijing (China); Chu, Yingjie; Xu, Ya; Qiu, Menglin; Xu, Mi [Key Laboratory of Beam Technology and Material Modification Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, 100875 Beijing (China)

2016-03-01

Highlights: • The radiation effect has a greater influence than doping effect on the hydrophilicity of RTV SR. • The implanted ions result in a new surface atomic bonding state and morphology. • Generating hydrophilic functional groups is a reason for the improved cell biocompatibility. • The micro roughness makes the hydrophilicity should be reduced due to the lotus effect. • Cell culture demonstrates that negative-ion implantation can improve biocompatibility. - Abstract: A negative cluster ion implantation system was built on the injector of a GIC4117 tandem accelerator. Next, the system was used to study the surface modification of room temperature vulcanization silicone rubber (RTV SR) for cell biocompatibility. The water contact angle was observed to decrease from 117.6° to 99.3° as the C{sub 1}{sup −} implantation dose was increased to 1 × 10{sup 16} ions/cm{sup 2}, and the effects of C{sub 1}{sup −}, C{sub 2}{sup −} and O{sub 1}{sup −} implantation result in only small differences in the water contact angle at 3 × 10{sup 15} ions/cm{sup 2}. These findings indicate that the hydrophilicity of RTV SR improves as the dose is increased and that the radiation effect has a greater influence than the doping effect on the hydrophilicity. There are two factors influence hydrophilicity of RTV: (1) based on the XPS and ATR-FTIR results, it can be inferred that ion implantation breaks the hydrophobic functional groups (Si−CH{sub 3}, Si−O−Si, C−H) of RTV SR and generates hydrophilic functional groups (−COOH, −OH, Si−(O){sub x} (x = 3,4)). (2) SEM reveals that the implanted surface of RTV SR appears the micro roughness such as cracks and wrinkles. The hydrophilicity should be reduced due to the lotus effect (Zhou Rui et al., 2009). These two factors cancel each other out and make the C-implantation sample becomes more hydrophilic in general terms. Finally, cell culture demonstrates that negative ion-implantation is an effective method

The influence of androgens, anti-androgens, and castration on cell proliferation in the jejunal and colonic crypt epithelia, and in dimethylhydrazine-induced adenocarcinoma of rat colon.

Science.gov (United States)

Tutton, P J; Barkla, D H

1982-01-01

Androgenic hormones have previously been shown to promote cell proliferation in the small intestine of rat and androgen receptors have been demonstrated in carcinomata of the large intestine of rat. In this study the influence of testosterone and of castration on epithelial cell proliferation in the small intestine, the large intestine and in dimethylhydrazine-induced colonic tumours is compared. Cell proliferation in the small intestine and in colonic tumours was accelerated by testosterone treatment, and cell proliferation in colonic tumours, but not in the small intestine, was retarded following castration. Cell proliferation in colonic tumours was also inhibited by the anti-androgenic drug, Flutamide. Testosterone and castration each failed to influence cell proliferation in the colonic crypt epithelium of both normal and carcinogen-treated animals.

Management of the failed posterior/multidirectional instability patient.

Science.gov (United States)

Forsythe, Brian; Ghodadra, Neil; Romeo, Anthony A; Provencher, Matthew T

2010-09-01

Although the results of operative treatment of posterior and multidirectional instability (P-MDI) of the shoulder have improved, they are not as reliable as those treated for anterior instability of the shoulder. This may be attributed to the complexities in the classification, etiology, and physical examination of a patient with suspected posterior and multidirectional instability. Failure to address the primary and concurrent lesion adequately and the development of pain and/or stiffness are contributing factors to the failure of P-MDI procedures. Other pitfalls include errors in history and physical examination, failure to recognize concomitant pathology, and problems with the surgical technique or implant failure. Patulous capsular tissues and glenoid version also play in role management of failed P-MDI patients. With an improved understanding of pertinent clinical complaints and physical examination findings and the advent of arthroscopic techniques and improved implants, successful strategies for the nonoperative and operative management of the patient after a failed posterior or multidirectional instability surgery may be elucidated. This article highlights the common presentation, physical findings, and radiographic workup in a patient that presents after a failed P-MDI repair and offers strategies for revision surgical repair.

The effect of valproic acid and oxcarbazepine on the distribution of adhesion molecules in embryo implantation

International Nuclear Information System (INIS)

Gürgen, Seren Gülşen; Erdoğan, Deniz; Coşkun, Zafer Kutay; Cansu, Ali

2012-01-01

This study was intended to investigate the effect of valproate (VPA) and oxcarbazepine (OXC) on embryo implantation in terms of extracellular matrix protein distribution. Thirty female rats (Wistar albino) were assigned to three groups of 10 animals each. Group 1 was administered two doses of saline solution, group 2, two doses of VPA at 300 mg/kg/day and group 3, two doses of OXC at 100 mg/kg/day, for a period of 3 months. Female rats with vaginal plugs mated with males for one night were placed into separate cages. Day of mating was taken as day 0, and implantation areas were obtained with rats being sacrificed on the morning of day 7. Immunohistochemical staining and electron microscopic protocols were then applied. At electron microscopic evaluation, extraembryonic endoderm and ectoderm layers could not be distinguished in semi-thin sections in the VPA group, while they were partially differentiated in the OXC group. At immunohistochemical staining, laminin was observed in the primary embryonic endoderm cell visceral and parietal layers, the uterine luminal epithelial cells and the secondary decidual zone in the control group. In the VPA group, it was weakly expressed in some embryo trophoectoderm cells and uterine luminal epithelial cells and moderately in some decidual cells. In the OXC group, it was moderately expressed in some trophoectoderm and decidual cells. Collagen IV was localized in the ectoplacental cone cells and secondary decidual zone and weak in the luminal epithelial cells in the control group. In the VPA and OXC groups, collagen IV was negative in all embryonic and maternal structures in the VPA and OXC groups. Vimentin was moderately expressed in the luminal epithelium and strongly expressed in the primary decidual zone and ectoplacental cone cells in the control group. In the VPA group, it was negative in the embryo trophoectoderm, decidual and uterine luminal epithelial cells, while in the OXC group it was moderately localized in the

Establishment of SHG-44 human glioma model in brain of wistar rat with stereotactic technique

International Nuclear Information System (INIS)

Hong Xinyu; Luo Yi'nan; Fu Shuanglin; Wang Zhanfeng; Bie Li; Cui Jiale

2004-01-01

Objective: To establish solid intracerebral human glioma model in Wistar rat with xenograft methods. Methods: The SHG-44 cells were injected into brain right caudate nucleus of previous immuno-inhibitory Wistar rats with stereotactic technique. The MRI scans were performed at 1 week and 2 weeks later after implantation. After 2 weeks the rats were killed and pathological examination and immunohistologic stain for human GFAP were used. Results: The MRI scan after 1 week of implantation showed the glioma was growing, pathological histochemical examination demonstrated the tumor was glioma. Human GFAP stain was positive. The growth rate of glioma model was about 60%. Conclusion: Solid intracerebral human glioma model in previous immuno-inhibitory Wistar rat is successfully established

Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

International Nuclear Information System (INIS)

Reichel, Christian; Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W.; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

2015-01-01

Passivated contacts (poly-Si/SiO x /c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF 2 ), the ion implantation dose (5 × 10 14  cm −2 to 1 × 10 16  cm −2 ), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV oc ) of 725 and 720 mV, respectively. For p-type passivated contacts, BF 2 implantations into intrinsic a-Si yield well passivated contacts and allow for iV oc of 690 mV, whereas implanted B gives poor passivation with iV oc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V oc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF 2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V oc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts

Effect of Modified Pectin Molecules on the Growth of Bone Cells

NARCIS (Netherlands)

Kokkonen, H.E.; Ilvesaro, J.M.; Morra, M.; Schols, H.A.; Tuukkanen, J.

2007-01-01

The aim of this study was to investigate molecular candidates for bone implant nanocoatings, which could improve biocompatibility of implant materials. Primary rat bone cells and murine preosteoblastic MC3T3-E1 cells were cultured on enzymatically modified hairy regions (MHR-A and MHR-B) of apple

Carbon Fiber Biocompatibility for Implants

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Richard Petersen

2016-01-01

Full Text Available Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p < 10−8 and 0.8 mm at 41.6% vs. 19.5% (p < 10−4, respectively. The review focuses on carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration.

Podoplanin immunopositive lymphatic vessels at the implant interface in a rat model of osteoporotic fractures.

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Katrin Susanne Lips

Full Text Available Insertion of bone substitution materials accelerates healing of osteoporotic fractures. Biodegradable materials are preferred for application in osteoporotic patients to avoid a second surgery for implant replacement. Degraded implant fragments are often absorbed by macrophages that are removed from the fracture side via passage through veins or lymphatic vessels. We investigated if lymphatic vessels occur in osteoporotic bone defects and whether they are regulated by the use of different materials. To address this issue osteoporosis was induced in rats using the classical method of bilateral ovariectomy and additional calcium and vitamin deficient diet. In addition, wedge-shaped defects of 3, 4, or 5 mm were generated in the distal metaphyseal area of femur via osteotomy. The 4 mm defects were subsequently used for implantation studies where bone substitution materials of calcium phosphate cement, composites of collagen and silica, and iron foams with interconnecting pores were inserted. Different materials were partly additionally functionalized by strontium or bisphosphonate whose positive effects in osteoporosis treatment are well known. The lymphatic vessels were identified by immunohistochemistry using an antibody against podoplanin. Podoplanin immunopositive lymphatic vessels were detected in the granulation tissue filling the fracture gap, surrounding the implant and growing into the iron foam through its interconnected pores. Significant more lymphatic capillaries were counted at the implant interface of composite, strontium and bisphosphonate functionalized iron foam. A significant increase was also observed in the number of lymphatics situated in the pores of strontium coated iron foam. In conclusion, our results indicate the occurrence of lymphatic vessels in osteoporotic bone. Our results show that lymphatic vessels are localized at the implant interface and in the fracture gap where they might be involved in the removal of

Podoplanin Immunopositive Lymphatic Vessels at the Implant Interface in a Rat Model of Osteoporotic Fractures

Science.gov (United States)

Lips, Katrin Susanne; Kauschke, Vivien; Hartmann, Sonja; Thormann, Ulrich; Ray, Seemun; Kampschulte, Marian; Langheinrich, Alexander; Schumacher, Matthias; Gelinsky, Michael; Heinemann, Sascha; Hanke, Thomas; Kautz, Armin R.; Schnabelrauch, Matthias; Schnettler, Reinhard; Heiss, Christian; Alt, Volker; Kilian, Olaf

2013-01-01

Insertion of bone substitution materials accelerates healing of osteoporotic fractures. Biodegradable materials are preferred for application in osteoporotic patients to avoid a second surgery for implant replacement. Degraded implant fragments are often absorbed by macrophages that are removed from the fracture side via passage through veins or lymphatic vessels. We investigated if lymphatic vessels occur in osteoporotic bone defects and whether they are regulated by the use of different materials. To address this issue osteoporosis was induced in rats using the classical method of bilateral ovariectomy and additional calcium and vitamin deficient diet. In addition, wedge-shaped defects of 3, 4, or 5 mm were generated in the distal metaphyseal area of femur via osteotomy. The 4 mm defects were subsequently used for implantation studies where bone substitution materials of calcium phosphate cement, composites of collagen and silica, and iron foams with interconnecting pores were inserted. Different materials were partly additionally functionalized by strontium or bisphosphonate whose positive effects in osteoporosis treatment are well known. The lymphatic vessels were identified by immunohistochemistry using an antibody against podoplanin. Podoplanin immunopositive lymphatic vessels were detected in the granulation tissue filling the fracture gap, surrounding the implant and growing into the iron foam through its interconnected pores. Significant more lymphatic capillaries were counted at the implant interface of composite, strontium and bisphosphonate functionalized iron foam. A significant increase was also observed in the number of lymphatics situated in the pores of strontium coated iron foam. In conclusion, our results indicate the occurrence of lymphatic vessels in osteoporotic bone. Our results show that lymphatic vessels are localized at the implant interface and in the fracture gap where they might be involved in the removal of lymphocytes, macrophages

Studies on implantation of 198Au-grain as a radiation therapy to cancer tissue

International Nuclear Information System (INIS)

Machida, Seiro

1975-01-01

The most effective dose of 198 Au-grain to be implanted and the clinicopathological findings after treatment are discussed. A safe dose of 198 Au-grain which could be implanted subcutaneously in rats, was under 2 mCi migration of 198 Au-grain was not recognized. In Yoshida sarcoma, transplanted subcutaneously into the backs of rats the most effective dose of 198 Au-grain was 2mCi/g of tumour tissue. However, about half of the rats implanted with this dosage died from the growing tumour. Histological examination of the implanted tumour tissue, revealed necrosis within a distance of only 0.4 mm from 198 Au-grain particles. In small metastatic tumours after 198 Au-grain implantation, there was necrosis i.e. pyknosis and karyolysis of the tumour cells, fibrosis and hyaline degeneration of the stroma. However, hardly any change in tumour size was detectable because of swelling and induration around the tumour. In some of the cases treated with 198 Au-grain combined with 60 Co or with chemotherapeutics, the tumour size was evidently reduced and became non-palable. Side effects were minimal except in one case which was afflicted temporarily with radiation sickness after an implantation of 200 mCi 198 Au-grain. In conclusion, the implantation of 198 Au-grain into the tumour was found to be very safe for the patients with surgically incurable cancer. Because of the short range of 198 Au-grain radioactivity, homogeneous density of 198 Au-grain into the whole tumour tissue is required. A combination with other radiations and/or with chemotherapeutics is also recommended. (author)

Antigen presenting cells costimulatory signaling during pre-implantation pregnancy 

Directory of Open Access Journals (Sweden)

Anna Sławek

2012-09-01

Full Text Available  Success of pregnancy depends on many factors. Three phenomena inducing immune tolerance against semi-allogeneic conceptus may play a crucial role in the pre-implantation period of pregnancy: influence of sex hormones in sex cycle, presence of oocyte or embryo and the presence of semen in the female reproductive tract. On the other hand dendritic cells are the most effective antigen-presenting cells in regulation of immune phenomena and also are considered as potent participants in inducing immune tolerance in the pregnancy. They communicate with T cells in cell contact-dependent manner or via cytokines. During cell-cell contacts, costimulatory molecules play a key role and their expression is often dependent on cytokines milieu. Both costimulatory molecules and cytokines influence generation of T regulatory cells. Interactions of these molecules are closely related. In this paper we would like to pay attention to the importance of antigen presenting cells costimulatory potency in immune regulation during a pre-implantation period of pregnancy.

Ability of mini-implant-facilitated micro-osteoperforations to accelerate tooth movement in rats.

Science.gov (United States)

Cheung, Tracy; Park, Juyoung; Lee, Deborah; Kim, Catherine; Olson, Jeffrey; Javadi, Shadi; Lawson, Gregory; McCabe, James; Moon, Won; Ting, Kang; Hong, Christine

2016-12-01

Although current techniques for accelerated tooth movement often involve invasive surgical procedures, micro-osteoperforations (MOPs) using mini-implants may facilitate orthodontic tooth movement without raising flaps, reduce surgical risks, and increase patient acceptance. In this study, we evaluated the effectiveness of mini-implant-facilitated MOPs in inducing accelerated tooth movement and investigated the potential risks for root resorption. Five MOPs were placed on the left side around the maxillary first molars in 6 rats using an automated mini-implant driver, whereas the right side received no MOPs as the control. Closed-coiled springs were secured from incisors to first molars for orthodontic tooth movement. Tooth movement was measured, and samples underwent radiologic and histologic analyses. The MOP side exhibited a 1.86-fold increase in the rate of tooth movement with decreased bone density and bone volume around the first molars compared with the control side. Hematoxylin and eosin and tartrate-resistant acid phosphatase analyses showed increased numbers of osteoclasts as well as new bone formation. Three-dimensional volumetric analysis of all 5 roots of the maxillary first molars demonstrated no statistically significant difference in root volumes. Mini-implant-facilitated MOPs accelerated tooth movement without increased risk for root resorption and therefore may become a readily available and efficient treatment option to shorten orthodontic treatment time with improved patient acceptance. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Embryonic mortality and intrauterine growth retardation (IUGR) associated with placental alterations in pregnant rats treated with methyl methanesulfonate (MMS) at the peri-implantation stage.

Science.gov (United States)

Yokoi, Ryohei; Hayashi, Morimichi; Tamura, Toru; Kobayashi, Kazuo; Kuroda, Junji; Kusama, Hiroshi; Kagami, Hiroshi; Ono, Tamao

2008-12-01

Embryonic mortality and intrauterine growth retardation (IUGR) are induced by exposure of rodents to xenobiotic agents during the pregastrulation period of development. We examined the time course of the effects of methyl methanesulfonate (MMS), an alkylating agent, on conceptus development in order to clarify the relative roles of the embryo and the placenta in their induction. Pregnant rats were treated orally with a single dose of MMS (200 mg/kg) in the morning of gestation day (GD) 6 (peri-implantation stage). Embryonic mortality was increased on GD12 and thereafter by MMS treatment, with newly dead embryos showing placental hypoplasia at GD12. Embryo or fetal weight was also smaller for MMS-treated dams than for control dams from GD14 to GD20. The labyrinth zone and junctional zone (JZ) of the placenta were thinner in MMS-treated rats from GD12 to GD17 and from GD12 to GD20 (except for GD17), respectively. Furthermore, MMS-treated dams showed a smaller number of glycogen cells in the JZ on GD14. In contrast, the placental glycogen concentration was higher and the expression of glucose transporter 1 in the JZ remained at GD20. These results indicate that exposure of pregnant rats to MMS at the peri-implantation stage of embryogenesis affects placental development and growth. The placental impairment induced by MMS was likely responsible for the embryonic death observed 6 days after exposure of dams to this agent as well as for the IUGR of surviving embryos or fetuses throughout the gestation period.

Regeneration of tracheal epithelium using mouse induced pluripotent stem cells.

Science.gov (United States)

Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Yoshie, Susumu; Otsuki, Koshi; Miyake, Masao; Hazama, Akihiro; Wada, Ikuo; Omori, Koichi

2016-01-01

Conclusion The findings demonstrated the potential use of induced pluripotent stem cells for regeneration of tracheal epithelium. Objective Autologous tissue implantation techniques using skin or cartilage are often applied in cases of tracheal defects with laryngeal inflammatory lesions and malignant tumor invasion. However, these techniques are invasive with an unstable clinical outcome. The purpose of this study was to investigate regeneration in a tracheal defect site of nude rats after implantation of ciliated epithelium that was differentiated from induced pluripotent stem cells. Method Embryoid bodies were formed from mouse induced pluripotent stem cells. They were cultured with growth factors for 5 days, and then cultured at the air-liquid interface. The degree of differentiation achieved prior to implantation was determined by histological findings and the results of real-time polymerase chain reaction. Embryoid bodies including ciliated epithelium were embedded into collagen gel that served as an artificial scaffold, and then implanted into nude rats, creating an 'air-liquid interface model'. Histological evaluation was performed 7 days after implantation. Results The ciliated epithelial structure survived on the lumen side of regenerated tissue. It was demonstrated histologically that the structure was composed of ciliated epithelial cells.

β-Cell dedifferentiation, reduced duct cell plasticity, and impaired β-cell mass regeneration in middle-aged rats.

Science.gov (United States)

Téllez, Noèlia; Vilaseca, Marina; Martí, Yasmina; Pla, Arturo; Montanya, Eduard

2016-09-01

Limitations in β-cell regeneration potential in middle-aged animals could contribute to the increased risk to develop diabetes associated with aging. We investigated β-cell regeneration of middle-aged Wistar rats in response to two different regenerative stimuli: partial pancreatectomy (Px + V) and gastrin administration (Px + G). Pancreatic remnants were analyzed 3 and 14 days after surgery. β-Cell mass increased in young animals after Px and was further increased after gastrin treatment. In contrast, β-cell mass did not change after Px or after gastrin treatment in middle-aged rats. β-Cell replication and individual β-cell size were similarly increased after Px in young and middle-aged animals, and β-cell apoptosis was not modified. Nuclear immunolocalization of neurog3 or nkx6.1 in regenerative duct cells, markers of duct cell plasticity, was increased in young but not in middle-aged Px rats. The pancreatic progenitor-associated transcription factors neurog3 and sox9 were upregulated in islet β-cells of middle-aged rats and further increased after Px. The percentage of chromogranin A+/hormone islet cells was significantly increased in the pancreases of middle-aged Px rats. In summary, the potential for compensatory β-cell hyperplasia and hypertrophy was retained in middle-aged rats, but β-cell dedifferentiation and impaired duct cell plasticity limited β-cell regeneration. Copyright © 2016 the American Physiological Society.

The Suitability of Zn–1.3%Fe Alloy as a Biodegradable Implant Material

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Alon Kafri

2018-02-01

Full Text Available Efforts to develop metallic zinc for biodegradable implants have significantly advanced following an earlier focus on magnesium (Mg and iron (Fe. Mg and Fe base alloys experience an accelerated corrosion rate and harmful corrosion products, respectively. The corrosion rate of pure Zn, however, may need to be modified from its reported ~20 µm/year penetration rate, depending upon the intended application. The present study aimed at evaluating the possibility of using Fe as a relatively cathodic biocompatible alloying element in zinc that can tune the implant degradation rate via microgalvanic effects. The selected Zn–1.3wt %Fe alloy composition produced by gravity casting was examined in vitro and in vivo. The in vitro examination included immersion tests, potentiodynamic polarization and impedance spectroscopy, all in a simulated physiological environment (phosphate-buffered saline, PBS at 37 °C. For the in vivo study, two cylindrical disks (seven millimeters diameter and two millimeters height were implanted into the back midline of male Wister rats. The rats were examined post implantation in terms of weight gain and hematological characteristics, including red blood cell (RBC, hemoglobin (HGB and white blood cell (WBC levels. Following retrieval, specimens were examined for corrosion rate measurements and histological analysis of subcutaneous tissue in the implant vicinity. In vivo analysis demonstrated that the Zn–1.3%Fe implant avoided harmful systemic effects. The in vivo and in vitro results indicate that the Zn–1.3%Fe alloy corrosion rate is significantly increased compared to pure zinc. The relatively increased degradation of Zn–1.3%Fe was mainly related to microgalvanic effects produced by a secondary Zn11Fe phase.

Activity of the rat osteocalcin basal promoter in osteoblastic cells is dependent upon homeodomain and CP1 binding motifs.

Science.gov (United States)

Towler, D A; Bennett, C D; Rodan, G A

1994-05-01

A detailed analysis of the transcriptional machinery responsible for osteoblast-specific gene expression should provide tools useful for understanding osteoblast commitment and differentiation. We have defined three cis-elements important for basal activity of the rat osteocalcin (OC) promoter, located at about -200 to -180, -170 to -138, and -121 to -64 relative to the transcription initiation site. A motif (TCTGATTGTGT) present in the region between -200 and -170 that binds a multisubunit CP1/NFY/CBF-like CAAT factor complex contributes significantly to high level basal activity and presumably functions as the CAAT box for the rat OC promoter. We show that the region -121 to 32 is sufficient to confer osteoblastic cell type specificity in transient transfection assays of cultured cell lines using luciferase as a reporter. The basal promoter is active in rodent osteoblastic cell lines, but not in rodent fibroblastic or muscle cell lines. Although the rat OC box (-100 to -74) contains a CAAT motif, we could not detect CP1-like CAAT factor binding to this region. In fact, we demonstrate that a Msx-1 (Hox 7.1) homeodomain binding motif (ACTAATTG; bottom strand) in the 3'-end of the rat OC box is necessary for high level activity of the rat OC basal promoter in osteoblastic cells. A nuclear factor that recognizes this motif appears to be present in osteoblastic ROS 17/2.8 cells, which produce OC, but not in fibroblastic ROS 25/1 cells, which fail to express OC. This ROS 17/2.8 nuclear factor also recognizes the A/T-rich DNA cognates of the homeodomain-containing POU family of transcription factors. Taken together, these data suggest that a ubiquitous CP1-like CAAT factor and a cell type-restricted homeodomain containing (Msx or POU family) transcription factor interact with the proximal rat OC promoter to direct appropriate basal OC transcription in osteoblastic cells.

Pterygoid implants for maxillofacial rehabilitation of a patient with a bilateral maxillectomy defect.

Science.gov (United States)

Bidra, Avinash S; May, George W; Tharp, Greggory E; Chambers, Mark S

2013-02-01

Bilateral maxillectomy is known to have serious esthetic and functional consequences. The retention and support of a maxillary obturator prosthesis in these patients is particularly challenging. Surgical placement of implants is also challenging because of the lack of available bone. Therefore, implant placement into remote sites such as zygoma has been advocated. Very few articles in the literature have discussed the use of pterygoid/pterygomaxillary implants in patients undergoing maxillectomy. This case report describes the maxillofacial rehabilitation of an elderly man who underwent a bilateral subtotal maxillectomy due to basaloid squamous cell carcinoma of the hard palate. After initial healing, the patient had a pterygoid implant placed on each side of the oral cavity. Zygomatic implants were also attempted, but they failed to osseointegrate. Both pterygoid implants showed successful osseointegration. These 2 implants significantly helped to retain a hollow maxillary obturator prosthesis that aided in improved swallowing, speech, and esthetics. To the authors' knowledge, this is the first report in the literature that describes usage of pterygoid implants for rehabilitation of a patient undergoing bilateral maxillectomy.

Chronic implantation of cuff electrodes on the pelvic nerve in rats is well tolerated and does not compromise afferent or efferent fibre functionality

Science.gov (United States)

Crook, J. J.; Brouillard, C. B. J.; Irazoqui, P. P.; Lovick, T. A.

2018-04-01

Objective. Neuromodulation of autonomic nerve activity to regulate physiological processes is an emerging field. Vagal stimulation has received most attention whereas the potential of modulate visceral function by targeting autonomic nerves within the abdominal cavity remains under-exploited. Surgery to locate intra-abdominal targets is inherently more stressful than for peripheral nerves. Electrode leads risk becoming entrapped by intestines and loss of functionality in the nerve-target organ connection could result from electrode migration or twisting. Since nociceptor afferents are intermingled with similar-sized visceral autonomic fibres, stimulation may induce pain. In anaesthetised rats high frequency stimulation of the pelvic nerve can suppress urinary voiding but it is not known how conscious animals would react to this procedure. Our objective therefore was to determine how rats tolerated chronic implantation of cuff electrodes on the pelvic nerve, whether nerve stimulation would be aversive and whether nerve-bladder functionality would be compromised. Approach. We carried out a preliminary de-risking study to investigate how conscious rats tolerated chronic implantation of electrodes on the pelvic nerve, their responsiveness to intermittent high frequency stimulation and whether functionality of the nerve-bladder connection became compromised. Main results. Implantation of cuff electrodes was well-tolerated. The normal diurnal pattern of urinary voiding was not disrupted. Pelvic nerve stimulation (up to 4 mA, 3 kHz) for 30 min periods evoked mild alerting at stimulus onset but no signs of pain. Stimulation evoked a modest (nerve temperature but the functional integrity of the nerve-bladder connection, reflected by contraction of the detrusor muscle in response to 10 Hz nerve stimulation, was not compromised. Significance. Chronic implantation of cuff electrodes on the pelvic nerve was found to be a well-tolerated procedure in rats and high frequency

Kupffer cell blockade prevents rejection of human insulinoma cell xenograft in rats

International Nuclear Information System (INIS)

Lazar, G. Jr.; Farkas, G.; Lazar, G.

1998-01-01

Alloantigens are recognized by T-cells in the context of both class I and class II antigen, but class II antigens predominate in the recognition of xenoantigens. Since class II molecules bind peptides derived from exogenous proteins that have been phagocytized and digested into small fragments by antigen presenting cells, in the present studies the effect of gadolinium chloride (GdCl 3 )-induced Kupffer cell blockade on the survival of discordant insulinoma cell xenografts was investigated. Insulinoma cells isolated by means of collagenase from human insulinoma and cultured were transplanted through the v. portae into the liver of streptozotocin-induced diabetic, male, CFY inbred rats. In the control, streptozotocin-treated rats, the decrease in blood glucose level was only transitory, in contrast with the GdCl 3 -pretreated diabetic rats, which remained normoglycaemic during the 2-week observation period. Histologically, in the liver and lung of rats pre-treated with GdCl 3 , large areas of extensively proliferating insulinoma cells were seen, whereas no insulinoma cells were seen in either the liver or the lung of diabetic-control rats, not-treated with GdCl 3 . These studies suggest that the Kupffer cells play significant roles in the recognition of xenoantigens and the induction of xenograft rejection. (orig.)

Subretinally transplanted embryonic stem cells rescue photoreceptor cells from degeneration in the RCS rats.

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Schraermeyer, U; Thumann, G; Luther, T; Kociok, N; Armhold, S; Kruttwig, K; Andressen, C; Addicks, K; Bartz-Schmidt, K U

2001-01-01

The Royal College of Surgeons (RCS) rat is an animal model for retinal degeneration such as the age-related macular degeneration. The RCS rat undergoes a progressive retinal degeneration during the early postnatal period. A potential treatment to prevent this retinal degeneration is the transplantation into the subretinal space of cells that would replace functions of the degenerating retinal pigment epithelium (RPE) cells or may form neurotrophic factors. In this study we have investigated the potential of subretinally transplanted embryonic stem cells to prevent the genetically determined photoreceptor cell degeneration in the RCS rat. Embryonic stem cells from the inner cell mass of the mouse blastocyst were allowed to differentiate to neural precursor cells in vitro and were then transplanted into the subretinal space of 20-day-old RCS rats. Transplanted and sham-operated rats were sacrificed 2 months following cell transplantation. The eyes were enucleated and photoreceptor degeneration was quantified by analyzing and determining the thickness of the outer nuclear layer by light and electron microscopy. In the eyes transplanted with embryonic cells up to 8 rows of photoreceptor cell nuclei were observed, whereas in nontreated control eyes the outer nuclear layer had degenerated completely. Transplantation of embryonic stem cells appears to delay photoreceptor cell degeneration in RCS rats.

Parathyroid hormone dependent T cell proliferation in uremic rats

DEFF Research Database (Denmark)

Lewin, E; Ladefoged, Jens; Brandi, L

1993-01-01

Chronic renal failure (CRF) is combined with an impairment of the immune system. The T cell may be a target for the action of parathyroid hormone (PTH). Rats with CRF have high blood levels of PTH. Therefore, the present investigation examined some aspects of the T cell function in both normal...... and CRF rats before and after parathyroidectomy and after an isogenic kidney transplantation. The T cell proliferative response to phytohemagglutinin (PHA) stimulation was significantly higher in peripheral blood mononuclear cell (PBMC) cultures obtained from CRF rats than from normal rats. After...... parathyroidectomy the T cells of normal as well as of uremic rats could still be significantly stimulated by PHA, but now no significant difference was seen. When CRF was reversed after an isogenic kidney transplantation and PTH reversed to levels in the normal range, the T cell proliferative response to PHA...

Expression of Pattern Recognition Receptors in Epithelial Cells Around Clinically Healthy Implants and Healthy Teeth.

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Calcaterra, Roberta; Di Girolamo, Michele; Mirisola, Concetta; Baggi, Luigi

2016-06-01

Gingival epithelial cells have a pivotal role in the recognition of microorganisms and damage-associated molecular pattern molecules and in the regulation of the immune response. The investigation of the behavior of Toll-like receptors (TLRs) and nucleotide oligomerization domain (NOD) like receptors (NLRs) around a healthy implant may help to address the first step of periimplantitis pathogenesis. To investigate by quantitative real-time polymerase chain reaction, the mRNA expressions of TLR2, TLR3, TLR4, TLR5, TLR6, TLR9, NOD1, NOD2, and NLRP3 from gingival epithelial cells of the sulcus around healthy implants and around healthy teeth. Two types of implant-abutment systems with tube-in-tube interface were tested. After 6 months of implant restoration, gingival epithelial cells were obtained from the gingival sulcus around the implants and around the adjacent teeth of 10 patients. Our results did not reach statistical significance among the mRNA expressions of TLR2, TLR3, TLR4, TLR5, TLR6, TLR9, NOD1, NOD2, and NLRP3 in epithelial cells around the implant versus around natural teeth. This study shows that the implant-abutment systems tested did not induce an immune response by the surrounding epithelial cells at 6 months since their positioning, as well as in the adjacent clincally healthy teeth.

Renal dysfunction induced by long-term exposure to depleted uranium in rats

Energy Technology Data Exchange (ETDEWEB)

Zhu, Guoying; Xiang, Xiqiao; Chen, Xiao; Wang, Lihua; Hu, Heping; Weng, Shifang [Fudan University, Institute of Radiation Medicine, Shanghai (China)

2009-01-15

Depleted uranium (DU) is a kind of radioactive heavy metal which can enter into the body via inhalation (aerosols), ingestion (drinking and eating) and wounds (embedded), and causes chemical and/or radiation-induced toxicities. In this study, male Sprague Dawley rats were surgically implanted in gastrocnemius muscle with DU fragments at three dose levels (low-dose, medium-dose and high-dose), with biologically inert tantalum (Ta) fragments served as controls. At 1 day, 7 days, and 3, 6, and 12 months after implantation, the rats were euthanized and tissue samples were collected, and uranium levels were measured in a variety of tissues by inductively coupled plasma-mass spectrometry (ICP-MS) to analyze the dynamic changes and distribution of uranium in rats. Thereafter, at 3, 6 and 12 months after implantation, the rats were euthanized after the collection of 24 h urine, blood and kidney samples were collected for analysis of DU-induced renal histopathologic changes and renal dysfunction. It was observed that DU concentrations in all the DU implanted groups were higher than that in Ta control group, and DU concentrations in the kidney increased with the implanted times, peaked at the 90 days after implantation, with a high correlation to the implanted DU doses, and then began to decrease gradually and slowly, and the DU concentrations in kidney still maintained at a relatively high level even at the 360 days after implantation. Otherwise, chronic DU contamination could induce the pathological changes of renal glomeruli, tubules and mesenchyme, such as interstitial fibrosis, enlarged interstice of renal tubular epithelial cells, tumefactions and necrosis of epithelial cells, shrinkage and disappearance of cavity of Bowman's capsule. By TEM, it was shown that the basement membrane of glomerulus was incrassated, mitochondrial of kidney proximal tubule had visible tumefaction and became bigger, and the mitochondrial cristae became shorter and disorderly in

Renal dysfunction induced by long-term exposure to depleted uranium in rats

International Nuclear Information System (INIS)

Zhu, Guoying; Xiang, Xiqiao; Chen, Xiao; Wang, Lihua; Hu, Heping; Weng, Shifang

2009-01-01

Depleted uranium (DU) is a kind of radioactive heavy metal which can enter into the body via inhalation (aerosols), ingestion (drinking and eating) and wounds (embedded), and causes chemical and/or radiation-induced toxicities. In this study, male Sprague Dawley rats were surgically implanted in gastrocnemius muscle with DU fragments at three dose levels (low-dose, medium-dose and high-dose), with biologically inert tantalum (Ta) fragments served as controls. At 1 day, 7 days, and 3, 6, and 12 months after implantation, the rats were euthanized and tissue samples were collected, and uranium levels were measured in a variety of tissues by inductively coupled plasma-mass spectrometry (ICP-MS) to analyze the dynamic changes and distribution of uranium in rats. Thereafter, at 3, 6 and 12 months after implantation, the rats were euthanized after the collection of 24 h urine, blood and kidney samples were collected for analysis of DU-induced renal histopathologic changes and renal dysfunction. It was observed that DU concentrations in all the DU implanted groups were higher than that in Ta control group, and DU concentrations in the kidney increased with the implanted times, peaked at the 90 days after implantation, with a high correlation to the implanted DU doses, and then began to decrease gradually and slowly, and the DU concentrations in kidney still maintained at a relatively high level even at the 360 days after implantation. Otherwise, chronic DU contamination could induce the pathological changes of renal glomeruli, tubules and mesenchyme, such as interstitial fibrosis, enlarged interstice of renal tubular epithelial cells, tumefactions and necrosis of epithelial cells, shrinkage and disappearance of cavity of Bowman's capsule. By TEM, it was shown that the basement membrane of glomerulus was incrassated, mitochondrial of kidney proximal tubule had visible tumefaction and became bigger, and the mitochondrial cristae became shorter and disorderly in alignment

Biology of teeth and implants: Host factors - pathology, regeneration, and the role of stem cells.

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Eggert, F-Michael; Levin, Liran

2018-01-01

In chronic periodontitis and peri-implantitis, cells of the innate and adaptive immune systems are involved directly in the lesions within the tissues of the patient. Absence of a periodontal ligament around implants does not prevent a biologic process similar to that of periodontitis from affecting osseointegration. Our first focus is on factors in the biology of individuals that are responsible for the susceptibility of such individuals to chronic periodontitis and to peri-implantitis. Genetic factors are of significant importance in susceptibility to these diseases. Genetic factors of the host affect the composition of the oral microbiome in the same manner that they influence other microbiomes, such as those of the intestines and of the lungs. Our second focus is on the central role of stem cells in tissue regeneration, in the functioning of innate and adaptive immune systems, and in metabolism of bone. Epithelial cell rests of Malassez (ERM) are stem cells of epithelial origin that maintain the periodontal ligament as well as the cementum and alveolar bone associated with the ligament. The tissue niche within which ERM are found extends into the supracrestal areas of collagen fiber-containing tissues of the gingivae above the bony alveolar crest. Maintenance and regeneration of all periodontal tissues involves the activity of a variety of stem cells. The success of dental implants indicates that important groups of stem cells in the periodontium are active to enable that biologic success. Successful replantation of avulsed teeth and auto-transplantation of teeth is comparable to placing dental implants, and so must also involve periodontal stem cells. Biology of teeth and biology of implants represents the biology of the various stem cells that inhabit specialized niches within the periodontal tissues. Diverse biologic processes must function together successfully to maintain periodontal health. Osseointegration of dental implants does not involve formation of

Bone marrow stem cells delivered into the subarachnoid space via cisterna magna improve repair of injured rat spinal cord white matter

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Marcol, Wiesław; Slusarczyk, Wojciech; Sieroń, Aleksander L; Koryciak-Komarska, Halina; Lewin-Kowalik, Joanna

2015-01-01

The influence of bone marrow stem cells on regeneration of spinal cord in rats was investigated. Young adult male Wistar rats were used (n=22). Focal injury of spinal cord white matter at Th10 level was produced using our original non-laminectomy method by means of high-pressured air stream. Cells from tibial and femoral bone marrow of 1-month old rats (n=3) were cultured, labeled with BrdU/Hoechst and injected into cisterna magna (experimental group) three times: immediately after spinal cord injury and 3 as well as 7 days later. Neurons in brain stem and motor cortex were labeled with FluoroGold (FG) delivered caudally from the injury site a week before the end of experiment. Functional outcome and morphological features of regeneration were analyzed during 12-week follow-up. The lesions were characterized by means of MRI. Maximal distance of expansion of implanted cells in the spinal cord was measured and the number of FG-positive neurons in the brain was counted. Rats treated with stem cells presented significant improvement of locomotor performance and spinal cord morphology when compared to the control group. Distance covered by stem cells was 7 mm from the epicenter of the injury. Number of brain stem and motor cortex FG-positive neurons in experimental group was significantly higher than in control. Obtained data showed that bone marrow stem cells are able to induce the repair of injured spinal cord white matter. The route of cells application via cisterna magna appeared to be useful for their delivery in spinal cord injury therapy. PMID:26628950

Hip arthroplasty in failed intertrochanteric fractures in elderly

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Javahir A Pachore

2013-01-01

Full Text Available Background: Failed intertrochanteric fractures in elderly patients are surgical challenge with limited options. Hip arthroplasty is a good salvage procedure even though it involves technical issues such as implant removal, bone loss, poor bone quality, trochanteric nonunion and difficulty of surgical exposure. Materials and Methods: 30 patients of failed intertrochanteric fractures where hip arthroplasty was done between May 2008 and December 2011 were included in study. 13 were males and 17 were females with average age of 67.3 years. There were 2 cemented bipolar arthroplasties, 19 uncemented bipolar, 4 cemented total hip arthroplasty and 5 uncemented total hip arthroplasties. 16 patients had a trochanteric nonunion, which was treated by tension band principles. Total hip was considered where there was acetabular damage due to the penetration of implant. Results: The average followup was 20 months (range 6-48 months. Patients were followed up from 6 to 48 months with average followup of 20 months. None of the patients were lost to followup. There was no dislocation. All patients were ambulatory at the final followup. Conclusion: A predictable functional outcome can be achieved by hip arthroplasty in elderly patients with failed intertrochanteric fractures. Though technically demanding, properly performed hip arthroplasty can be a good salvage option for this patient group.

Role of cyclic GMP in cells with the properties of smooth muscle cultured from the rat myometrium

International Nuclear Information System (INIS)

Krall, J.F.; Morin, A.

1986-01-01

Cells growing in culture with previously described properties of rat uterine smooth muscle accumulated 45 Ca 2+ from the medium. Ca 2+ uptake by these cells was stimulated by the addition to the medium of 8-bromo-cGMP but not by 8-bromo-cAMP. Ca 2+ uptake was also stimulated by carbachol and by the nitro-vasodilator nitroprusside. Although cholinergic agonists have been shown previously to stimulate contraction but not cGMP synthesis in the rat myometrium, both carbachol and nitroprusside stimulated cGMP production by the cultured cells. These results suggested the cells had cholinergic receptor-medicated functions that reflected some neurotransmitter-sensitive properties of uterine smooth muscle in situ. When determined by a specific radioligand binding assay, subcellular fractions of the cultured cells bound muscarinic cholinergic agonists and antagonists with affinities expected of the muscarinic receptor. The cells were also sensitive to the β-adrenergic catecholamine agonist isoproterenol, which stimulated cAMP production but not Ca 2+ uptake. Carbachol failed to inhibit isoproterenol-dependent cAMP production, which is an important property of the cholinergic receptor in uterine smooth muscle in situ. These results suggest some but not all acetylcholine-sensitive properties of uterine smooth muscle may be retained in cell culture

Berberine ameliorates collagen-induced arthritis in rats by suppressing Th17 cell responses via inducing cortistatin in the gut.

Science.gov (United States)

Yue, Mengfan; Xia, Yufeng; Shi, Can; Guan, Chunge; Li, Yunfan; Liu, Rui; Wei, Zhifeng; Dai, Yue

2017-09-01

Berberine, an isoquinoline alkaloid, has been reported to ameliorate various autoimmune diseases including rheumatoid arthritis by oral administration. However, its mechanism remains mysterious due to an extremely low bioavailability. The fact that berberine readily accumulates in the gut, the largest endocrine organ in the body, attracted us to explore its anti-arthritic mechanism in view of the induction of intestinal immunosuppressive neuropeptides. In this study, berberine (200 mg·kg -1 , i.g.) was shown to ameliorate collagen-induced arthritis in rats, which was manifested by the reduction of clinical signs and joint destruction, as well as marked down-regulation of Th17 cell frequency and interleukin-17 level in blood. In contrast, an intravenous injection of berberine failed to affect arthritis in rats, implying that its anti-arthritic effect was gut-dependent. Further studies revealed that oral berberine selectively elevated the levels of cortistatin, of five gut-derived neuropeptides tested, in the intestines and sera of arthrititic rats. Antagonists of ghrelin/growth hormone secretagogue receptor 1 (a subtype of cortistatin receptor) almost completely abolished the ameliorative effect of berberine on arthritis and Th17 cell responses in rats. In vitro, berberine showed a moderate ability to promote the expression of cortistatin in nerve cells, which was strengthened when the nerve cells were cocultured with enteroendocrine cells to induce an autocrine/paracrine environment. In summary, oral berberine exerted anti-arthritic effect through inhibiting the Th17 cell response, which was closely associated with the induction of cortistatin generation from gut through augmenting autocrine/paracrine action between enteric nerve cells and endocrine cells. © 2017 Federation of European Biochemical Societies.

Chronic intrathecal cannulation enhances nociceptive responses in rats

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Almeida F.R.C.

2000-01-01

Full Text Available The influence of a chronically implanted spinal cannula on the nociceptive response induced by mechanical, chemical or thermal stimuli was evaluated. The hyperalgesia in response to mechanical stimulation induced by carrageenin or prostaglandin E2 (PGE2 was significantly increased in cannulated (Cn rats, compared with naive (Nv or sham-operated (Sh rats. Only Cn animals presented an enhanced nociceptive response in the first phase of the formalin test when low doses were used (0.3 and 1%. The withdrawal latency to thermal stimulation of a paw inflamed by carrageenin was significantly reduced in Cn rats but not in Nv or Sh rats. In contrast to Nv and Sh rats, injection in Cn animals of a standard non-steroid anti-inflammatory drug, indomethacin, either intraperitoneally or into the spinal cord via an implanted cannula or by direct puncture of the intrathecal space significantly blocked the intensity of the hyperalgesia induced by PGE2. Cannulated animals treated with indomethacin also showed a significant inhibition of second phase formalin-induced paw flinches. Histopathological analysis of the spinal cord showed an increased frequency of mononuclear inflammatory cells in the Cn groups. Thus, the presence of a chronically implanted cannula seems to cause nociceptive spinal sensitization to mechanical, chemical and thermal stimulation, which can be blocked by indomethacin, thus suggesting that it may result from the spinal release of prostaglandins due to an ongoing mild inflammation.

The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats.

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Sá, Jairo Zacchê de; Aguiar, José Lamartine de Andrade; Cruz, Adriana Ferreira; Schuler, Alexandre Ricardo Pereira; Lima, José Ricardo Alves de; Marques, Olga Martins

2012-12-01

To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005), 1 and 4 (p=0.024), 2 and 3 (p=0.003), 2 and 4 (p=0.001). These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.

Generation and characterization of rat liver stem cell lines and their engraftment in a rat model of liver failure

Science.gov (United States)

Kuijk, Ewart W.; Rasmussen, Shauna; Blokzijl, Francis; Huch, Meritxell; Gehart, Helmuth; Toonen, Pim; Begthel, Harry; Clevers, Hans; Geurts, Aron M.; Cuppen, Edwin

2016-01-01

The rat is an important model for liver regeneration. However, there is no in vitro culture system that can capture the massive proliferation that can be observed after partial hepatectomy in rats. We here describe the generation of rat liver stem cell lines. Rat liver stem cells, which grow as cystic organoids, were characterized by high expression of the stem cell marker Lgr5, by the expression of liver progenitor and duct markers, and by low expression of hepatocyte markers, oval cell markers, and stellate cell markers. Prolonged cultures of rat liver organoids depended on high levels of WNT-signalling and the inhibition of BMP-signaling. Upon transplantation of clonal lines to a Fah−/− Il2rg−/− rat model of liver failure, the rat liver stem cells engrafted into the host liver where they differentiated into areas with FAH and Albumin positive hepatocytes. Rat liver stem cell lines hold potential as consistent reliable cell sources for pharmacological, toxicological or metabolic studies. In addition, rat liver stem cell lines may contribute to the development of regenerative medicine in liver disease. To our knowledge, the here described liver stem cell lines represent the first organoid culture system in the rat. PMID:26915950

Intermittent Fasting Modulation of the Diabetic Syndrome in Streptozotocin-Injected Rats

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Louiza Belkacemi

2012-01-01

Full Text Available This study investigates the effects of intermittent overnight fasting in streptozotocin-induced diabetic rats (STZ rats. Over 30 days, groups of 5-6 control or STZ rats were allowed free food access, starved overnight, or exposed to a restricted food supply comparable to that ingested by the intermittently fasting animals. Intermittent fasting improved glucose tolerance, increased plasma insulin, and lowered Homeostatis Model Assessment index. Caloric restriction failed to cause such beneficial effects. The β-cell mass, as well as individual β-cell and islet area, was higher in intermittently fasting than in nonfasting STZ rats, whilst the percentage of apoptotic β-cells appeared lower in the former than latter STZ rats. In the calorie-restricted STZ rats, comparable findings were restricted to individual islet area and percentage of apoptotic cells. Hence, it is proposed that intermittent fasting could represent a possible approach to prevent or minimize disturbances of glucose homeostasis in human subjects.

Reconstruction of rat calvarial defects with human mesenchymal stem cells and osteoblast-like cells in poly-lactic-co-glycolic acid scaffolds

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C Zong

2010-09-01

Full Text Available Human mesenchymal stem cells (hMSCs can be used for xenogenic transplantation due to their low immunogenicity, high proliferation rate, and multi-differentiation potentials. Therefore, hMSCs are an ideal seeding source for tissue engineering. The present study evaluates the reconstruction effects of hMSCs and osteoblast-like cells differentiated from hMSCs in poly-lactic-co-glycolic acid (PLGA scaffolds on the calvarial defect of rats. Two bilateral full-thickness defects (5mm in diameter were created in the calvarium of nonimmunosuppressed Sprague-Dawley rats. The defects were filled by PLGA scaffolds with hMSCs (hMSC Construct or with osteoblast-like cells differentiated from hMSCs (Osteoblast Construct. The defects without any graft (Blank Defect or filled with PLGA scaffold without any cells (Blank Scaffold were used as controls. Evaluation was performed using macroscopic view, histology and immunohistochemical analysis respectively at 10 and 20 weeks after transplantation. In addition, fluorescent carbocyanine CM-Dil was used to track the implanted cells in vivo during transplantation. The results showed that while both hMSC Construct and Osteoblast Construct led to an effective reconstruction of critical-size calvarial defects, the bone reconstruction potential of hMSC Construct was superior to that of Osteoblast Construct in non-autogenous applications. Our findings verify the feasibility of the use of xenogenic MSCs for tissue engineering and demonstrate that undifferentiated hMSCs are more suitable for bone reconstruction in xenotransplantation models.

Characterization of a Polymer-Based, Fully Organic Prosthesis for Implantation into the Subretinal Space of the Rat.

Science.gov (United States)

Antognazza, Maria Rosa; Di Paolo, Mattia; Ghezzi, Diego; Mete, Maurizio; Di Marco, Stefano; Maya-Vetencourt, José Fernando; Maccarone, Rita; Desii, Andrea; Di Fonzo, Fabio; Bramini, Mattia; Russo, Angela; Laudato, Lucia; Donelli, Ilaria; Cilli, Michele; Freddi, Giuliano; Pertile, Grazia; Lanzani, Guglielmo; Bisti, Silvia; Benfenati, Fabio

2016-09-01

Replacement strategies arise as promising approaches in case of inherited retinal dystrophies leading to blindness. A fully organic retinal prosthesis made of conjugated polymers layered onto a silk fibroin substrate is engineered. First, the biophysical and surface properties are characterized; then, the long-term biocompatibility is assessed after implantation of the organic device in the subretinal space of 3-months-old rats for a period of five months. The results indicate a good stability of the subretinal implants over time, with preservation of the physical properties of the polymeric layer and a tight contact with the outer retina. Immunoinflammatory markers detect only a modest tissue reaction to the surgical insult and the foreign body that peaks shortly after surgery and progressively decreases with time to normal levels at five months after implantation. Importantly, the integrity of the polymeric layer in direct contact with the retinal tissue is preserved after five months of implantation. The recovery of the foreign-body tissue reaction is also associated with a normal b-wave in the electroretinographic response. The results demonstrate that the device implanted in nondystrophic eyes is well tolerated, highly biocompatible, and suitable as retinal prosthesis in case of photoreceptor degeneration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Anaplastic large cell lymphoma associated with breast implants

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Vid Bajuk

2017-02-01

Full Text Available An increasing number of women worldwide decide for esthetic correction of breasts with silicone implants and post-cancer breast reconstruction with tissue expanders and silicone breast implants. It is estimated that more than 10 million women around the globe have them. Tere are approximately 200 known cases of patients with anaplastic large cell lymphoma (ALCL linked with silicone breast implants reported in medical literature. ALCL is a rare disease with an annual incidence of 0.1–0.3/100 000 women with breast silicone implants. In the presence of clinical signs, physician should also consider this rare form of ALCL in differential diagnosis. Patients are on average 50 years old. Long afer implantation surgery, the patient may experience breast swelling, pain and/or asymmetry. In diagnostics, ultrasound and cytological examination are required. During ultrasound examination fluid formation (seroma or solid tumor mass can be detected. Treatment is individualized. Due to tumor nature, implant resection and total capsulectomy are usually indicated; also, chemo- and radiotherapy might rarely be required. Five-year survival rate depends on tumor form and correlates well with clinical fndings of seroma or solid mass. In the more frequent form, seroma, fve-year survival rate is 100 %, while in the case of solid tumor mass fve-year survival rate is 75 %. The rarity of this disease makes it difficult to diagnose, but nevertheless, early detection and treatment are important for better recovery.

Revisiting the stability of mini-implants used for orthodontic anchorage

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Chung-Chen Jane Yao

2015-11-01

Conclusion: This study revealed that once the dental surgeon becomes familiar with the procedure, the stability of orthodontic mini-implants depends on the type of mini-implant, age of the patient, implantation site, and the healing time of the mini-implant. Miniplates are a more feasible anchorage system when miniscrews fail repeatedly.

Effects of different hierarchical hybrid micro/nanostructure surfaces on implant osseointegration.

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Cheng, Bingkun; Niu, Qiang; Cui, Yajun; Jiang, Wei; Zhao, Yunzhuan; Kong, Liang

2017-06-01

Hierarchical hybrid micro/nanostructure implant surfaces are considered to better mimic the hierarchical structure of bone and the nanostructures substantively influence osseointegration through managing cell behaviors. To enhance implant osseointegration for further clinical application, we evaluated the material properties and osseointegration effects of hierarchical surfaces with different nano-morphologies, using a rat model. Two representative surface fabrication methods, hydrofluoric (HF) acid etching combined with anodization (HF + AN) or magnetron sputtering (HF + MS), were selected. Sample material properties were evaluated by scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoemission spectroscopy, and epoxy resin docking tensile test. Implants with different surfaces were inserted into the distal femurs of rats. After 12 weeks, osseointegration was examined by microcomputed tomography (micro-CT), histological, and biomechanical tests. Tensile testing demonstrated high bonding strength at coating/implant in the HF + MS group. Micro-CT revealed increased bone volume/total volume and significantly reduced trabecular separation in HF + MS versus other groups. Histological analysis showed significantly higher HF + MS bone-to-implant contact (74.78 ± 4.40%) versus HF + AN (65.11 ± 5.10%) and machined samples (56.03 ± 3.23%). The maximal HF + MS pull-out force increased by 33.7% versus HF + AN. These results indicated that HF + MS surfaces exhibited superior material property in terms of bonding strength and favorable implant osseointegration compared to other groups. © 2017 Wiley Periodicals, Inc.

Peripheral white blood cells profile of biodegradable metal implant in mice animal model

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Paramitha, Devi; Noviana, Deni; Estuningsih, Sri; Ulum, Mokhamad Fakhrul; Nasution, Ahmad Kafrawi; Hermawan, Hendra

2015-09-01

Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found.

Peripheral white blood cells profile of biodegradable metal implant in mice animal model

Energy Technology Data Exchange (ETDEWEB)

Paramitha, Devi; Noviana, Deni, E-mail: deni@ipb.ac.id; Estuningsih, Sri [Faculty of Veterinary Medicine, Bogor Agricultural University (IPB), Bogor (Indonesia); Ulum, Mokhamad Fakhrul [Faculty of Veterinary Medicine, Bogor Agricultural University (IPB), Bogor (Indonesia); Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru (Malaysia); Nasution, Ahmad Kafrawi [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru (Malaysia); Faculty of Engineering, Muhammadiyah University of Riau (UMRI), Pekanbaru (Indonesia); Hermawan, Hendra [Department of Mining, Metallurgical and Materials Engineering & CHU de Québec Research Center, Laval University (ULaval) (Canada)

2015-09-30

Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found.

Dental implants in patients with ectodermal dysplasia: A systematic review.

Science.gov (United States)

Chrcanovic, Bruno Ramos

2018-05-21

This study sought to assess the clinical outcome and survival rate of oral implants placed in individuals with ectodermal dysplasia (ED), based on previously published studies. An electronic search without time restrictions was undertaken in 5 databases (PubMed/Medline, Web of Science, ScienceDirect, J-Stage, Lilacs). Descriptive statistics, Kaplan Meier estimator and implant failure probability were calculated. 90 publications were included, reporting 228 ED patients that received 1472 implants (1392 conventional, 47 zygomatic, 33 mini-implants). Mean age of the patients was 20.2 ± 6.8 years (2-56). Patients had a mean of 3.2 ± 2.5 maxillary and 2.1 ± 2.6 mandibular permanent teeth (min-max, 0-14). Patients received a mean of 8.2 ± 3.8 implants (1-20). Most implants were placed in the third decade of life, 24.6% of the implants were placed in children (0-17 years of age). 1391 implants had information on follow-up (72 failures, 5.2%). The 20-year CSR was 84.6%. The probability of failure was 4.5% (95%CI 3.5%-5.6%, p < 0.001). Additional treatments performed were Le Fort I (99 implants, 20 patients, 3.5% failed), grafting (497 implants, 77 patients, 5.2% failed), distraction osteogenesis (79 implants, 16 patients, 10.1% failed). Mean follow-up was 42.9 ± 41.9 months (min-max, 2-240). Dental implants placed in ED patients, either infants or adults, present a high survival rate (20-year CSR 84.6%). Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Hydroxyapatite coating affects the Wnt signaling pathway during peri-implant healing in vivo.

Science.gov (United States)

Thorfve, A; Lindahl, C; Xia, W; Igawa, K; Lindahl, A; Thomsen, P; Palmquist, A; Tengvall, P

2014-03-01

Owing to its bio- and osteoconductivity, hydroxyapatite (HA) is a widely used implant material, but its osteogenic properties are only partly evaluated in vitro and in vivo. The present study focused on bone healing adjacent to HA-coated titanium (Ti) implants, with or without incorporated lithium ions (Li(+)). Special attention was given to the Wnt signaling pathway. The implants were inserted into rat tibia for 7 or 28 days and analyzed ex vivo, mainly by histomorphometry and quantitative real-time polymerase chain reaction (qPCR). HA-coated implants showed, irrespective of Li(+) content, bone-implant contact (BIC) and removal torque values significantly higher than those of reference Ti. Further, the expression of OCN, CTSK, COL1A1, LRP5/6 and WISP1 was significantly higher in implant-adherent cells of HA-coated implants, with or without Li(+). Significantly higher β-catenin expression and significantly lower COL2A1 expression were observed in peri-implant bone cells from HA with 14 ng cm(-2) released Li(+). Interestingly, Ti implants showed a significantly larger bone area (BA) in the threads than HA with 39 ng cm(-2) released Li(+), but had a lower BIC than any HA-coated implant. This study shows that HA, with or without Li(+), is a strong activator of the Wnt signaling pathway, and may to some degree explain its high bone induction capacity. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

In vivo delivery of recombinant human growth hormone from genetically engineered human fibroblasts implanted within Baxter immunoisolation devices.

Science.gov (United States)

Josephs, S F; Loudovaris, T; Dixit, A; Young, S K; Johnson, R C

1999-01-01

Continuous delivery of therapeutic peptide to the systemic circulation would be the optimal treatment for a variety of diseases. The Baxter TheraCyte system is a membrane encapsulation system developed for implantation of tissues, cells such as endocrine cells or cell lines genetically engineered for therapeutic peptide delivery in vivo. To demonstrate the utility of this system, cell lines were developed which expressed human growth hormone (hGH) at levels exceeding 1 microgram per million cells per day. These were loaded into devices which were then implanted into juvenile nude rats. Significant levels of hGH of up to 2.5 ng/ml were detected in plasma throughout the six month duration of the study. In contrast, animals implanted with free cells showed peak plasma levels of 0.5 to 1.2 ng four days after implantation with no detectable hGH beyond 10 days. Histological examination of explanted devices showed they were vascularized and contained cells that were viable and morphologically healthy. After removal of the implants, no hGH could be detected which confirmed that the source of hGH was from cells contained within the device. The long term expression of human growth hormone as a model peptide has implications for the peptide therapies for a variety of human diseases using membrane encapsulated cells.

In vivo dendritic cell depletion reduces breeding efficiency, affecting implantation and early placental development in mice.

Science.gov (United States)

Krey, Gesa; Frank, Pierre; Shaikly, Valerie; Barrientos, Gabriela; Cordo-Russo, Rosalia; Ringel, Frauke; Moschansky, Petra; Chernukhin, Igor V; Metodiev, Metodi; Fernández, Nelson; Klapp, Burghard F; Arck, Petra C; Blois, Sandra M

2008-09-01

Implantation of mammalian embryos into their mother's uterus ensures optimal nourishment and protection throughout development. Complex molecular interactions characterize the implantation process, and an optimal synchronization of the components of this embryo-maternal dialogue is crucial for a successful reproductive outcome. In the present study, we investigated the role of dendritic cells (DC) during implantation process using a transgenic mouse system (DTRtg) that allows transient depletion of CD11c+ cells in vivo through administration of diphtheria toxin. We observed that DC depletion impairs the implantation process, resulting in a reduced breeding efficiency. Furthermore, the maturity of uterine natural killer cells at dendritic cell knockout (DCKO) implantation sites was affected as well; as demonstrated by decreased perforin expression and reduced numbers of periodic-acid-Schiff (PAS)-positive cells. This was accompanied by disarrangements in decidual vascular development. In the present study, we were also able to identify a novel DC-dependent protein, phosphatidylinositol transfer protein beta (PITPbeta), involved in implantation and trophoblast development using a proteomic approach. Indeed, DCKO mice exhibited substantial anomalies in placental development, including hypocellularity of the spongiotrophoblast and labyrinthine layers and reduced numbers of trophoblast giant cells. Giant cells also down-regulated their expression of two characteristic markers of trophoblast differentiation, placental lactogen 1 and proliferin. In view of these findings, dendritic cells emerge as possible modulators in the orchestration of events leading to the establishment and maintenance of pregnancy.

Enzymatic Fuel Cells: Towards Self-Powered Implantable and Wearable Diagnostics.

Science.gov (United States)

Gonzalez-Solino, Carla; Lorenzo, Mirella Di

2018-01-29

With the rapid progress in nanotechnology and microengineering, point-of-care and personalised healthcare, based on wearable and implantable diagnostics, is becoming a reality. Enzymatic fuel cells (EFCs) hold great potential as a sustainable means to power such devices by using physiological fluids as the fuel. This review summarises the fundamental operation of EFCs and discusses the most recent advances for their use as implantable and wearable self-powered sensors.

Enzymatic Fuel Cells: Towards Self-Powered Implantable and Wearable Diagnostics

OpenAIRE

Carla Gonzalez-Solino; Mirella Di Lorenzo

2018-01-01

With the rapid progress in nanotechnology and microengineering, point-of-care and personalised healthcare, based on wearable and implantable diagnostics, is becoming a reality. Enzymatic fuel cells (EFCs) hold great potential as a sustainable means to power such devices by using physiological fluids as the fuel. This review summarises the fundamental operation of EFCs and discusses the most recent advances for their use as implantable and wearable self-powered sensors.

Superparamagnetic iron oxide nanoparticles function as a long-term, multi-modal imaging label for non-invasive tracking of implanted progenitor cells.

Directory of Open Access Journals (Sweden)

Christina A Pacak

Full Text Available The purpose of this study was to determine the ability of superparamagnetic iron oxide (SPIO nanoparticles to function as a long-term tracking label for multi-modal imaging of implanted engineered tissues containing muscle-derived progenitor cells using magnetic resonance imaging (MRI and X-ray micro-computed tomography (μCT. SPIO-labeled primary myoblasts were embedded in fibrin sealant and imaged to obtain intensity data by MRI or radio-opacity information by μCT. Each imaging modality displayed a detection gradient that matched increasing SPIO concentrations. Labeled cells were then incorporated in fibrin sealant, injected into the atrioventricular groove of rat hearts, and imaged in vivo and ex vivo for up to 1 year. Transplanted cells were identified in intact animals and isolated hearts using both imaging modalities. MRI was better able to detect minuscule amounts of SPIO nanoparticles, while μCT more precisely identified the location of heavily-labeled cells. Histological analyses confirmed that iron oxide particles were confined to viable, skeletal muscle-derived cells in the implant at the expected location based on MRI and μCT. These analyses showed no evidence of phagocytosis of labeled cells by macrophages or release of nanoparticles from transplanted cells. In conclusion, we established that SPIO nanoparticles function as a sensitive and specific long-term label for MRI and μCT, respectively. Our findings will enable investigators interested in regenerative therapies to non-invasively and serially acquire complementary, high-resolution images of transplanted cells for one year using a single label.

Enhanced periodontal tissue regeneration by periodontal cell implantation

NARCIS (Netherlands)

Yu, N.; Oortgiesen, D.A.W.; Bronckers, A.L.J.J.; Yang, F.; Walboomers, X.F.; Jansen, J.A.

2013-01-01

Aim Due to a lack of regenerative potential, current treatments for periodontal defects do not always provide satisfactory clinical results. Previously, the implantation of a biomaterial scaffold-cell construct has been suggested as a clinically achievable approach. In this study, it was aimed to

Evaluation of porous vitreous carbon or silicon implants by radiology in rat's skull Avaliação radiológica de implantes de carbono vítreo poroso ou silicone em crânio de ratos

Directory of Open Access Journals (Sweden)

Marcelo Paulo Vaccari-Mazzetti

2008-06-01

Full Text Available PURPOSE: Evaluate by CT the use of porous vitreous carbon (PVC and silicon (S implants as the replacement bone in the craniofacial skeleton of rats. METHODS: 40 rats divided in: Group A (n=20 PVC submitted to the implant of a fragment in skull. After the euthanasia, the animals were divided into two subgroups: A I: 10 animals, studied in the 7th postoperative day (P.O and AII: 10 animals, studied in the 28th P.O. In group B, S, 20 rats were submitted to S implant in the skull. All other steps were identical to group A, with designation of subgroups BI and BII. CT with beams in axial cuts of 1 mm thickness to obtain 3-D information It was used Hounsfield scale for evaluate the radio density of the implant. They were used non parametric tests to analyze the results. RESULTS: The 7th PO boss remained in the two groups, but for 28th PO, observed reduction in the volume of the implant in Group A, not observed in group B. CT studies noticed different radio densities around all of S prostheses (pseudo-capsule, that don't appeared in CPV implants. The S has remained unchanged in the CT, but the CPV has had a modification in its radio density (pOBJETIVO: Realizar avaliação através de tomografia computadorizada (TC de implantes de carbono vítreo poroso (CVP e silicone (S para sua utilização na substituição óssea no esqueleto craniofacial de ratos. MÉTODOS: Foram utilizados 40 ratos Wistar divididos em: Grupo A (n=20, implantes subperiostais de CVP no crânio. Após o momento da eutanásia os animais foram divididos em dois subgrupos: A I: 10 animais, estudados no 7(0 dia pós-operatório (PO e AII: 10 animais, estudados no 28(0 PO. No grupo B (n=20, os ratos foram submetidos ao implante de silicone no crânio. Todas outras etapas foram idênticas ao grupo A, com a designação de subgrupos BI e BII. Foi realizada tomografia computadorizada com cortes axiais de 1 mm de espessura para obtenção de imagens tridimensionais. A escala de Hounsfield

Inverse relationship between tumour proliferation markers and connexin expression in a malignant cardiac tumour originating from mesenchymal stem cell engineered tissue in a rat in-vivo model.

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Cathleen eSpath

2013-04-01

Full Text Available Background: Recently, we demonstrated the beneficial effects of engineered heart tissues for the treatment of dilated cardiomyopathy in rats. For further development of this technique we started to produce engineered tissue (ET from mesenchymal stem cells. Interestingly, we observed a malignant tumour invading the heart with an inverse relationship between proliferation markers and connexin-expression.Methods: Commercial CD54+/CD90+/CD34-/CD45- bone marrow derived mesenchymal rat stem cells (cBM-MSC, characterized were used for production of mesenchymal stem-cell-ET (MSC-ET by suspending them in a collagen-I, matrigel-mixture and cultivating for 14 days with electrical stimulation. 3 MSC-ET were implanted around the beating heart of adult rats for days. Another 3 MSC-ET were produced from freshly isolated rat bone marrow derived stem cells (sBM-MSC.Results: 3 weeks after implantation of the MSC-ETs the hearts were surgically excised. While in 5/6 cases the ET was clearly distinguishable and was found as a ring containing mostly connective tissue around the heart, in 1/6 the heart was completely surrounded by a huge, undifferentiated, pleomorphic tumour originating from the cMSC-ET (cBM-MSC, classified as a high grade malignant sarcoma. Quantitatively we found a clear inverse relationship between cardiac connexin-expression (Cx43, Cx40 or Cx45 and increased Ki-67 expression (Cx43: p<0.0001, Cx45: p<0.03, Cx40: p<0.014. At the tumour-heart border there were significantly more Ki-67 positive cells (p=0.001, and only 2% Cx45 and Ki-67-expressing cells, while the other connexins were nearly completely absent (p<0.0001.Conclusions and hypothesis: These observations strongly suggest the hypothesis, that invasive tumour growth is accompanied by reduction in connexins. This implicates that gap junction communication between tumour and normal tissue is reduced or absent, which could mean that growth and differentiation signals can not be exchanged.

THE IMPLANT INFECTION PARADOX : WHY DO SOME SUCCEED WHEN OTHERS FAIL? OPINION AND DISCUSSION PAPER

NARCIS (Netherlands)

Yue, C.; Zhao, Bingran; Ren, Y.; Kuijer, R.; van der Mei, H. C.; Busscher, H. J.; Rochford, E. T. J.

2015-01-01

Biomaterial-implants are frequently used to restore function and form of human anatomy. However, the presence of implanted biomaterials dramatically elevates infection risk. Paradoxically, dental-implants placed in a bacteria-laden milieu experience moderate failure-rates, due to infection (0.0-1.1

The response of breast cancer cells to mesenchymal stem cells: a possible role of inflammation by breast implants.

Science.gov (United States)

Orciani, Monia; Lazzarini, Raffaella; Scartozzi, Mario; Bolletta, Elisa; Mattioli-Belmonte, Monica; Scalise, Alessandro; Di Benedetto, Giovanni; Di Primio, Roberto

2013-12-01

Breast implants are widely used and at times might cause inflammation as a foreign body, followed by fibrous capsule formation around the implant. In cancer, the inflamed stroma is essential for preservation of the tumor. Mesenchymal stem cells can be recruited to sites of inflammation, and their role in cancer development is debated. The authors assessed the effects of inflammation caused by breast implants' effects on tumor. Mesenchymal stem cells were isolated from the fibrous capsules of women who underwent a second operation after 1 year (presenting inflammation) or after 20 years (not presenting inflammation) since initial surgery. After characterization, cells were co-cultured with MCF7, a breast cancer cell line. The expression of genes involved in oncogenesis, proliferation, and epithelial-to-mesenchymal transition was investigated, followed by Western blot analyses. After co-culture with mesenchymal stem cells from the inflamed capsule, MCF7 induced a dose- and time-dependent increase in proliferation. Polymerase chain reaction analyses revealed a dysregulation of genes involved in oncogenesis, proliferation, and epithelial-to-mesenchymal transition. The subsequent evaluation by Western blot did not confirm these results, showing only a modest decrease in the expression of E-cadherin after co-culture with mesenchymal stem cells (both derived from inflamed or control capsules). These data indicate that inflammation caused by breast implants partially affects proliferation of MCF7 but does not influence key mechanisms of tumor development.

Implantable biochemical fuel cell. [German patent

Energy Technology Data Exchange (ETDEWEB)

Richter, G; Rao, J R

1978-09-14

Implantable biochemical fuel cells for the operation of heart pacemakers or artificial hearts convert oxidisable body substances such as glucose on the anode side and reduce the oxygen contained in body fluids at the cathode. The anode and cathode are separated by membranes which are impermeable to albumen and blood corpuscles in body fluids. A chemical shortcircuit cannot occur in practice if, according to the invention, one or more selective oxygen electrodes with carbon as catalyst are arranged so that the mixture which diffuses into the cell from body fluids during operation reaches the fuel cell electrode through the porous oxygen electrode. The membranes used must be permeable to water. Cellulose, polymerised polyvinyl alcohol or an ion exchanger with a buffering capacity between pH5 and 8 act as permeable materials.

Enzymatic Fuel Cells: Towards Self-Powered Implantable and Wearable Diagnostics

Science.gov (United States)

Gonzalez-Solino, Carla; Lorenzo, Mirella Di

2018-01-01

With the rapid progress in nanotechnology and microengineering, point-of-care and personalised healthcare, based on wearable and implantable diagnostics, is becoming a reality. Enzymatic fuel cells (EFCs) hold great potential as a sustainable means to power such devices by using physiological fluids as the fuel. This review summarises the fundamental operation of EFCs and discusses the most recent advances for their use as implantable and wearable self-powered sensors. PMID:29382147

Enzymatic Fuel Cells: Towards Self-Powered Implantable and Wearable Diagnostics

Directory of Open Access Journals (Sweden)

Carla Gonzalez-Solino

2018-01-01

Full Text Available With the rapid progress in nanotechnology and microengineering, point-of-care and personalised healthcare, based on wearable and implantable diagnostics, is becoming a reality. Enzymatic fuel cells (EFCs hold great potential as a sustainable means to power such devices by using physiological fluids as the fuel. This review summarises the fundamental operation of EFCs and discusses the most recent advances for their use as implantable and wearable self-powered sensors.

A multi-topographical-instrument analysis: the breast implant texture measurement

Science.gov (United States)

Garabédian, Charles; Delille, Rémi; Deltombe, Raphaël; Anselme, Karine; Atlan, Michael; Bigerelle, Maxence

2017-06-01

Capsular contracture is a major complication after implant-based breast augmentation. To address this tissue reaction, most manufacturers texture the outer breast implant surfaces with calibrated salt grains. However, the analysis of these surfaces on sub-micron scales has been under-studied. This scale range is of interest to understand the future of silicone particles potentially released from the implant surface and the aetiology of newly reported complications, such as Anaplastic Large Cell Lymphoma. The surface measurements were accomplished by tomography and by two optical devices based on interferometry and on focus variation. The robustness of the measurements was investigated from the tissue scale to the cellular scale. The macroscopic pore-based structure of the textured implant surfaces is consistently measured by the three instruments. However, the multi-scale analyses start to be discrepant in a scale range between 50 µm and 500 µm characteristic of a finer secondary roughness regardless of the pore shape. The focus variation and the micro-tomography would fail to capture this roughness regime because of a focus-related optical artefact and of step-shaped artefact respectively.

Numeric and volumetric changes in Leydig cells during aging of rats.

Science.gov (United States)

Neves, Bruno Vinicius Duarte; Lorenzini, Fernando; Veronez, Djanira; Miranda, Eduardo Pereira de; Neves, Gabriela Duarte; Fraga, Rogério de

2017-10-01

To analyze the effects of aging in rats on the nuclear volume, cytoplasmic volume, and total volume of Leydig cells, as well as their number. Seventy-two Wistar rats were divided into six subgroups of 12 rats, which underwent right orchiectomy at 3, 6, 9, 12, 18, and 24 months of age. The weight and volume of the resected testicles were assessed. A stereological study of Leydig cells was conducted, which included measurements of cell number and nuclear, cytoplasmic, and total cell volumes. The weight and volume of the resected testicles showed reductions with age. Only the subgroup composed of 24-month old rats showed a decrease in the nuclear volume of Leydig cells. Significant reductions in the cytoplasmic volume and total volume of Leydig cells were observed in 18- and 24-month old rats. The number of Leydig cells did not vary significantly with age. Aging in rats resulted in reduction of the nuclear, cytoplasmic, and total cell volumes of Leydig cells. There was no change in the total number of these cells during aging.

Immunophenotypic characterization of human T cells after in vitro exposure to different silicone breast implant surfaces.

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Giuseppe Cappellano

Full Text Available The most common complication of silicone breast implants is capsular contracture (massive scar formation around the implant. We postulate that capsular contracture is always a sequel to inflammatory processes, with both innate and adaptive immune mechanisms participating. In general, fibroblasts and macrophages have been used as cell types to evaluate in vitro the biocompatibility of breast implant surfaces. Moreover, also T cells have been found at the implant site at the initial stage of fibrous capsule formation. However, only few studies have addressed the influence of surfaces with different textures on T-cell responses. The aim of the present study was to investigate the immune response of human peripheral blood mononuclear cells (PBMC to commercially available silicone breast implants in vitro. PBMC from healthy female blood donors were cultured on each silicone surface for 4 days. Proliferation and phenotype of cultured cells were assessed by flow cytometry. Cytokine levels were determined by multiplex and real-time assay. We found that silicone surfaces do not induce T-cell proliferation, nor do they extensively alter the proportion of T cell subsets (CD4, CD8, naïve, effector memory. Interestingly, cytokine profiling identified matrix specific differences, especially for IL-6 and TNF-α on certain surface topographies that could lead to increased fibrosis.

Effects of Diclofenac, L-NAME, L-Arginine, and Pentadecapeptide BPC 157 on Gastrointestinal, Liver, and Brain Lesions, Failed Anastomosis, and Intestinal Adaptation Deterioration in 24 Hour-Short-Bowel Rats.

Science.gov (United States)

Lojo, Nermin; Rasic, Zarko; Zenko Sever, Anita; Kolenc, Danijela; Vukusic, Darko; Drmic, Domagoj; Zoricic, Ivan; Sever, Marko; Seiwerth, Sven; Sikiric, Predrag

2016-01-01

Stable gastric pentadecapeptide BPC 157 was previously used to ameliorate wound healing following major surgery and counteract diclofenac toxicity. To resolve the increasing early risks following major massive small bowel resectioning surgery, diclofenac combined with nitric oxide (NO) system blockade was used, suggesting therapy with BPC 157 and the nitric oxide synthase (NOS substrate) L-arginine, is efficacious. Immediately after anastomosis creation, short-bowel rats were untreated or administered intraperitoneal diclofenac (12 mg/kg), BPC 157 (10 μg/kg or 10 ng/kg), L-NG-nitroarginine methyl ester (L-NAME, 5 mg/kg), L-arginine (100 mg/kg) alone or combined, and assessed 24 h later. Short-bowel rats exhibited poor anastomosis healing, failed intestine adaptation, and gastrointestinal, liver, and brain lesions, which worsened with diclofenac. This was gradually ameliorated by immediate therapy with BPC 157 and L-arginine. Contrastingly, NOS-blocker L-NAME induced further aggravation and lesions gradually worsened. Specifically, rats with surgery alone exhibited mild stomach/duodenum lesions, considerable liver lesions, and severe cerebral/hippocampal lesions while those also administered diclofenac showed widespread severe lesions in the gastrointestinal tract, liver, cerebellar nuclear/Purkinje cells, and cerebrum/hippocampus. Rats subjected to surgery, diclofenac, and L-NAME exhibited the mentioned lesions, worsening anastomosis, and macro/microscopical necrosis. Thus, rats subjected to surgery alone showed evidence of deterioration. Furtheremore, rats subjected to surgery and administered diclofenac showed worse symptoms, than the rats subjected to surgery alone did. Rats subjected to surgery combined with diclofenac and L-NAME showed the worst deterioration. Rats subjected to surgery exhibited habitual adaptation of the remaining small intestine, which was markedly reversed in rats subjected to surgery and diclofenac, and those with surgery, diclofenac, and

Transplantation of rat embryonic stem cell-derived retinal progenitor cells preserves the retinal structure and function in rat retinal degeneration.

Science.gov (United States)

Qu, Zepeng; Guan, Yuan; Cui, Lu; Song, Jian; Gu, Junjie; Zhao, Hanzhi; Xu, Lei; Lu, Lixia; Jin, Ying; Xu, Guo-Tong

2015-11-09

Degenerative retinal diseases like age-related macular degeneration (AMD) are the leading cause of blindness. Cell transplantation showed promising therapeutic effect for such diseases, and embryonic stem cell (ESC) is one of the sources of such donor cells. Here, we aimed to generate retinal progenitor cells (RPCs) from rat ESCs (rESCs) and to test their therapeutic effects in rat model. The rESCs (DA8-16) were cultured in N2B27 medium with 2i, and differentiated to two types of RPCs following the SFEBq method with modifications. For rESC-RPC1, the cells were switched to adherent culture at D10, while for rESC-RPC2, the suspension culture was maintained to D14. Both RPCs were harvested at D16. Primary RPCs were obtained from P1 SD rats, and some of them were labeled with EGFP by infection with lentivirus. To generate Rax::EGFP knock-in rESC lines, TALENs were engineered to facilitate homologous recombination in rESCs, which were cotransfected with the targeting vector and TALEN vectors. The differentiated cells were analyzed with live image, immunofluorescence staining, flow cytometric analysis, gene expression microarray, etc. RCS rats were used to mimic the degeneration of retina and test the therapeutic effects of subretinally transplanted donor cells. The structure and function of retina were examined. We established two protocols through which two types of rESC-derived RPCs were obtained and both contained committed retina lineage cells and some neural progenitor cells (NPCs). These rESC-derived RPCs survived in the host retinas of RCS rats and protected the retinal structure and function in early stage following the transplantation. However, the glia enriched rESC-RPC1 obtained through early and longer adherent culture only increased the b-wave amplitude at 4 weeks, while the longer suspension culture gave rise to evidently neuronal differentiation in rESC-RPC2 which significantly improved the visual function of RCS rats. We have successfully differentiated

Human olfactory bulb neural stem cells mitigate movement disorders in a rat model of Parkinson's disease.

Science.gov (United States)

Marei, Hany E S; Lashen, Samah; Farag, Amany; Althani, Asmaa; Afifi, Nahla; A, Abd-Elmaksoud; Rezk, Shaymaa; Pallini, Roberto; Casalbore, Patrizia; Cenciarelli, Carlo

2015-07-01

Parkinson's disease (PD) is a neurological disorder characterized by the loss of midbrain dopaminergic (DA) neurons. Neural stem cells (NSCs) are multipotent stem cells that are capable of differentiating into different neuronal and glial elements. The production of DA neurons from NSCs could potentially alleviate behavioral deficits in Parkinsonian patients; timely intervention with NSCs might provide a therapeutic strategy for PD. We have isolated and generated highly enriched cultures of neural stem/progenitor cells from the human olfactory bulb (OB). If NSCs can be obtained from OB, it would alleviate ethical concerns associated with the use of embryonic tissue, and provide an easily accessible cell source that would preclude the need for invasive brain surgery. Following isolation and culture, olfactory bulb neural stem cells (OBNSCs) were genetically engineered to express hNGF and GFP. The hNFG-GFP-OBNSCs were transplanted into the striatum of 6-hydroxydopamin (6-OHDA) Parkinsonian rats. The grafted cells survived in the lesion environment for more than eight weeks after implantation with no tumor formation. The grafted cells differentiated in vivo into oligodendrocyte-like (25 ± 2.88%), neuron-like (52.63 ± 4.16%), and astrocyte -like (22.36 ± 1.56%) lineages, which we differentiated based on morphological and immunohistochemical criteria. Transplanted rats exhibited a significant partial correction in stepping and placing in non-pharmacological behavioral tests, pole and rotarod tests. Taken together, our data encourage further investigations of the possible use of OBNSCs as a promising cell-based therapeutic strategy for Parkinson's disease. © 2014 Wiley Periodicals, Inc.

HIV-1 transgenic rats develop T cell abnormalities

International Nuclear Information System (INIS)

Reid, William; Abdelwahab, Sayed; Sadowska, Mariola; Huso, David; Neal, Ashley; Ahearn, Aaron; Bryant, Joseph; Gallo, Robert C.; Lewis, George K.; Reitz, Marvin

2004-01-01

HIV-1 infection leads to impaired antigen-specific T cell proliferation, increased susceptibility of T cells to apoptosis, progressive impairment of T-helper 1 (Th1) responses, and altered maturation of HIV-1-specific memory cells. We have identified similar impairments in HIV-1 transgenic (Tg) rats. Tg rats developed an absolute reduction in CD4 + and CD8 + T cells able to produce IFN-γ following activation and an increased susceptibility of T cells to activation-induced apoptosis. CD4 + and CD8 + effector/memory (CD45RC - CD62L - ) pools were significantly smaller in Tg rats compared to non-Tg controls, although the converse was true for the naieve (CD45RC + CD62L + ) T cell pool. Our interpretation is that the HIV transgene causes defects in the development of T cell effector function and generation of specific effector/memory T cell subsets, and that activation-induced apoptosis may be an essential factor in this process

A telemetry study on the chronic effects of microdialyis probe implantation on the activity pattern and temperature rhythm of the rat

NARCIS (Netherlands)

Drijfhout, W.J.; Kemper, R.H.A.; Meerlo, P.; Koolhaas, J.M.; Grol, C.J.; Westerink, B.H.C.

1995-01-01

The present study describes the effects of implantation of microdialysis probes on temperature and activity rhythms of the rat, measured with a telemetry system. For comparison two widely used types of microdialysis probes were investigated, a transcerebral probe, inserted into the pineal gland and

Low-intensity pulsed ultrasound enhances bone formation around miniscrew implants.

Science.gov (United States)

Ganzorig, Khaliunaa; Kuroda, Shingo; Maeda, Yuichi; Mansjur, Karima; Sato, Minami; Nagata, Kumiko; Tanaka, Eiji

2015-06-01

Miniscrew implants (MSIs) are currently used to provide absolute anchorage in orthodontics; however, their initial stability is an issue of concern. Application of low-intensity pulsed ultrasound (LIPUS) can promote bone healing. Therefore, LIPUS application may stimulate bone formation around MSIs and enhance their initial stability. To investigate the effect of LIPUS exposure on bone formation after implantation of titanium (Ti) and stainless steel (SS) MSIs. MSIs made of Ti-6Al-4V and 316L SS were placed on rat tibiae and treated with LIPUS. The bone morphology around MSIs was evaluated by scanning electron microscopy and three-dimensional micro-computed tomography. MC3T3-E1 cells cultured on Ti and SS discs were treated with LIPUS, and the temporary expression of alkaline phosphatase (ALP) was examined. Bone-implant contact increased gradually from day 3 to day 14 after MSI insertion. LIPUS application increased the cortical bone density, cortical bone thickness, and cortical bone rate after implantation of Ti and SS MSIs (P<0.05). LIPUS exposure induced ALP upregulation in MC3T3-E1 cells at day 3 (P<0.05). LIPUS enhanced bone formation around Ti and SS MSIs, enhancing the initial stability of MSIs. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Wireless and Batteryless Microsystem with Implantable Grid Electrode/3-Dimensional Probe Array for ECoG and Extracellular Neural Recording in Rats

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Chih-Wei Chang

2013-04-01

Full Text Available This paper presents the design and implementation of an integrated wireless microsystem platform that provides the possibility to support versatile implantable neural sensing devices in free laboratory rats. Inductive coupled coils with low dropout regulator design allows true long-term recording without limitation of battery capacity. A 16-channel analog front end chip located on the headstage is designed for high channel account neural signal conditioning with low current consumption and noise. Two types of implantable electrodes including grid electrode and 3D probe array are also presented for brain surface recording and 3D biopotential acquisition in the implanted target volume of tissue. The overall system consumes less than 20 mA with small form factor, 3.9 × 3.9 cm2 mainboard and 1.8 × 3.4 cm2 headstage, is packaged into a backpack for rats. Practical in vivo recordings including auditory response, brain resection tissue and PZT-induced seizures recording demonstrate the correct function of the proposed microsystem. Presented achievements addressed the aforementioned properties by combining MEMS neural sensors, low-power circuit designs and commercial chips into system-level integration.

Immunological Response to Biodegradable Magnesium Implants

Science.gov (United States)

Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

2014-04-01

The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

A combined wet/dry sipping cell for investigating failed triga fuel elements

International Nuclear Information System (INIS)

Boeck, H.; Gallhammer, H.; Hammer, J.; Israr, M.

1987-08-01

A sipping cell to detect failed triga fuel has been designed and constructed at the Atominstitut. The cell allows both wet- and dry sipping of one single standard triga fuel element. In the dry sipping method the fuel element may be electrically heated up to a maximum temperature of about 300 0 C to allow the detection of temperature dependent fission product release from the fuel element. 20 figs., 1 tab. (Author)

Growth Inhibition of Breast Cancer in Rat by AAV Mediated Angiostatin Gene

Institute of Scientific and Technical Information of China (English)

LI Ran; CHEN Hong; REN Chang-shan

2007-01-01

Objective: To observe growth inhibition effect of adeno-associated viral vectors (AAV) mediated angiostatin (ANG) gene on implanted breast cancer in rat and its mechanism. Methods: Gene transfer technique was used to transfer AAV-ANG to the tumor. Growth curves were drawn to observe the growth of breast cancer implanted in rat, and immunohistochemical method was used to detect the effects of angiostatin on microvesel density (MVD) of breast cancer implanted in rat. Results: Angiostatin inhibited the growth of breast cancer implanted in rat and decreased the microvessel density of tumor. Conclusion: Expression of an angiostatin transgene can suppress the growth of breast cancer implanted in rat through the inhibition of the growth of microvessels, surggesting that angiostatin gene transfer technique may be effective against breast cancer.

Amniotic fluid stem cells with low γ-interferon response showed behavioral improvement in Parkinsonism rat model.

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Yu-Jen Chang

Full Text Available Amniotic fluid stem cells (AFSCs are multipotent stem cells that may be used in transplantation medicine. In this study, AFSCs established from amniocentesis were characterized on the basis of surface marker expression and differentiation potential. To further investigate the properties of AFSCs for translational applications, we examined the cell surface expression of human leukocyte antigens (HLA of these cells and estimated the therapeutic effect of AFSCs in parkinsonian rats. The expression profiles of HLA-II and transcription factors were compared between AFSCs and bone marrow-derived mesenchymal stem cells (BMMSCs following treatment with γ-IFN. We found that stimulation of AFSCs with γ-IFN prompted only a slight increase in the expression of HLA-Ia and HLA-E, and the rare HLA-II expression could also be observed in most AFSCs samples. Consequently, the expression of CIITA and RFX5 was weakly induced by γ-IFN stimulation of AFSCs compared to that of BMMSCs. In the transplantation test, Sprague Dawley rats with 6-hydroxydopamine lesioning of the substantia nigra were used as a parkinsonian-animal model. Following the negative γ-IFN response AFSCs injection, apomorphine-induced rotation was reduced by 75% in AFSCs engrafted parkinsonian rats but was increased by 53% in the control group after 12-weeks post-transplantation. The implanted AFSCs were viable, and were able to migrate into the brain's circuitry and express specific proteins of dopamine neurons, such as tyrosine hydroxylase and dopamine transporter. In conclusion, the relative insensitivity AFSCs to γ-IFN implies that AFSCs might have immune-tolerance in γ-IFN inflammatory conditions. Furthermore, the effective improvement of AFSCs transplantation for apomorphine-induced rotation paves the way for the clinical application in parkinsonian therapy.

Adenovirus-Mediated Over-Expression of Nrf2 Within Mesenchymal Stem Cells (MSCs Protected Rats Against Acute Kidney Injury

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Mohammad Mohammadzadeh-Vardin

2015-06-01

Full Text Available Purpose: Recent developments in the field of cell therapy have led to a renewed interest in treatment of acute kidney injury (AKI. However, the early death of transplanted mesenchymal stem cells (MSCs in stressful microenvironment of a recipient tissue is a major problem with this kind of treatment. The objective of this study was to determine whether overexpression of a cytoprotective factor, nuclear factor erythroid-2 related factor 2 (Nrf2, in MSCs could protect rats against AKI. Methods: The Nrf2 was overexpressed in MSCs by recombinant adenoviruses, and the MSCs were implanted to rats suffering from cisplatin-induced AKI. Results: The obtained results showed that transplantation with the engineered MSCs ameliorates cisplatin-induced AKI. Morphologic features of the investigated kidneys showed that transplantation with the MSCs in which Nrf2 had been overexpressed significantly improved the complications of AKI. Conclusion: These findings suggested that the engineered MSCs might be a good candidate to be further evaluated in clinical trials. However, detailed studies must be performed to investigate the possible carcinogenic effect of Nrf2 overexpression.

Nanosurface design of dental implants for improved cell growth and function

Science.gov (United States)

Pan, Hsu-An; Hung, Yao-Ching; Chiou, Jin-Chern; Tai, Shih-Ming; Chen, Hsin-Hung; Huang, G. Steven

2012-08-01

A strategy was proposed for the topological design of dental implants based on an in vitro survey of optimized nanodot structures. An in vitro survey was performed using nanodot arrays with dot diameters ranging from 10 to 200 nm. MG63 osteoblasts were seeded on nanodot arrays and cultured for 3 days. Cell number, percentage undergoing apoptotic-like cell death, cell adhesion and cytoskeletal organization were evaluated. Nanodots with a diameter of approximately 50 nm enhanced cell number by 44%, minimized apoptotic-like cell death to 2.7%, promoted a 30% increase in microfilament bundles and maximized cell adhesion with a 73% increase in focal adhesions. An enhancement of about 50% in mineralization was observed, determined by von Kossa staining and by Alizarin Red S staining. Therefore, we provide a complete range of nanosurfaces for growing osteoblasts to discriminate their nanoscale environment. Nanodot arrays present an opportunity to positively and negatively modulate cell behavior and maturation. Our results suggest a topological approach which is beneficial for the design of dental implants.

Biomechanical Evaluation of Rat Skull Defects, 1, 3, and 6 Months after Implantation with Osteopromotive Substances

DEFF Research Database (Denmark)

Jones, Leigh Robert; Thomsen, Jesper Skovhus; Mosekilde, Lis

2007-01-01

as unfilled controls. The repaired defects were evaluated biomechanically using a modified punch out test 1, 3, or 6 months postoperatively. Results: The maximum load carried in the DBM group was significantly higher than in the bone chips, hydroxyapatite, and control groups after one month of healing......Purpose: To compare the mechanical strength of surgically created and healed rat calvarial defects having been filled with three different osteopromotive substances: hydroxyapatite, intramembraneous demineralised bone matrix (DBM), and autogenous bone chips. Material: Sixty adult male Wistar rats...... were divided into three groups of 20 animals, each group representing healing times of one, three, or six months. Methods: Identical 5 mm bilateral critical size defects were trephined into the parietal bones and hydroxyapatite, DBM, or autogenous bone chips were implanted into the defects, or left...

Effects of SH-reagents of different molecular size upon glucose metabolism in isolated rat fat cells

International Nuclear Information System (INIS)

Kather, H.; Simon, B.

1975-01-01

To study the role of membrane SH-groups in glucose transport of isolated rat fat cells we compared the effects of a small organic mercurial reagent p-CMB with those of a large p-CMB-derivative - p-CMB-Dextran, MW approximately 10,000 -. It could be shown that both compounds were of almost identical reactivity on fat cell homogenate metabolism. When applied to intact fat cells uncoupled p-CMB showed an 1) insulin-like enhancement of 14 C incorporation from (U- 14 C) glucose into CO 2 and triglyceride, 2) inhibition of the insulin-stimulatory effect on these parameters and 3) inhibition of basal glucose uptake dependent on the concentrations used. Identical concentrations of p-CMB-Dextran, however, failed to influence basal glucose uptake as well as the insulin mediated increase in glucose metabolism. (orig.) [de

Effects of SH-reagents of different molecular size upon glucose metabolism in isolated rat fat cells

Energy Technology Data Exchange (ETDEWEB)

Kather, H; Simon, B [Heidelberg Univ. (F.R. Germany). Klinisches Inst. fuer Herzinfarktforschung

1975-09-01

To study the role of membrane SH-groups in glucose transport of isolated rat fat cells we compared the effects of a small organic mercurial reagent p-CMB with those of a large p-CMB-derivative - p-CMB-Dextran, MW approximately 10,000 -. It could be shown that both compounds were of almost identical reactivity on fat cell homogenate metabolism. When applied to intact fat cells uncoupled p-CMB showed an 1) insulin-like enhancement of /sup 14/C incorporation from (U-/sup 14/C) glucose into CO/sub 2/ and triglyceride, 2) inhibition of the insulin-stimulatory effect on these parameters and 3) inhibition of basal glucose uptake dependent on the concentrations used. Identical concentrations of p-CMB-Dextran, however, failed to influence basal glucose uptake as well as the insulin mediated increase in glucose metabolism.

Histological and radiographic evaluation of the muscle tissue of rats after implantation of bone morphogenic protein (rhBMP-2 in a scaffold of inorganic bone and after stimulation with low-power laser light

Directory of Open Access Journals (Sweden)

Bengtson Antonio

2010-01-01

Full Text Available Objective: The present study histologically and radiologically evaluates the muscle tissue of rats after implantation of bone morphogenic protein (rhBMP-2 in a natural inorganic bone mineral scaffold from a bull calf femur and irradiation with low-power light laser. Materials and Methods: The right and left hind limbs of 16 rats were shaved and an incision was made in the muscle on the face corresponding to the median portion of the tibia, into which rhBMP-2 in a scaffold of inorganic bone was implanted. Two groups of limbs were formed: control (G1 and laser irradiation (G2. G2 received diode laser light applied in the direction of the implant, at a dose of 8 J/cm2 for three minutes. On the 7th, 21st, 40th and 112th days after implantation, hind limbs of 4 animals were radiographed and their implants removed together with the surrounding tissue for study under the microscope. The histological results were graded as 0=absence, 1=slight presence, 2=representative and 3=very representative, with regard to the following events: formation of osteoid structure, acute inflammation, chronic inflammation, fibrin deposition, neovascularization, foreign-body granuloma and fibrosis. Results: There were no statistically significant differences in these events at each evaluation times, between the two groups (P > 0.05; Mann-Whitney test. Nevertheless, it could be concluded that the natural inorganic bone matrix with rhBMP-2, from the femur of a bull calf, is a biocompatible combination. Conclusions: Under these conditions, the inductive capacity of rhBMP-2 for cell differentiation was inhibited. There was a slight acceleration in tissue healing in the group that received irradiation with low-power laser light.

Silicon solar cells made by ion implantation and glow discharge

International Nuclear Information System (INIS)

Ponpon, J.P.; Siffert, P.

1975-01-01

Three different methods of silicon solar cell preparation are considered and investigated: low energy implantation, glow discharge and prebombarded Schottky barriers. The properties of the contact layers realized by these processes are compared in terms of junction depth and sheet resistance. Preliminary results show the usefulness of these techniques for terrestrial solar cell realization [fr

Edaravone combined with Schwann cell transplantation may repair spinal cord injury in rats

Directory of Open Access Journals (Sweden)

Shu-quan Zhang

2015-01-01

Full Text Available Edaravone has been shown to delay neuronal apoptosis, thereby improving nerve function and the microenvironment after spinal cord injury. Edaravone can provide a favorable environment for the treatment of spinal cord injury using Schwann cell transplantation. This study used rat models of complete spinal cord transection at T 9. Six hours later, Schwann cells were transplanted in the head and tail ends of the injury site. Simultaneously, edaravone was injected through the caudal vein. Eight weeks later, the PKH-26-labeled Schwann cells had survived and migrated to the center of the spinal cord injury region in rats after combined treatment with edaravone and Schwann cells. Moreover, the number of PKH-26-labeled Schwann cells in the rat spinal cord was more than that in rats undergoing Schwann cell transplantation alone or rats without any treatment. Horseradish peroxidase retrograde tracing revealed that the number of horseradish peroxidase-positive nerve fibers was greater in rats treated with edaravone combined withSchwann cells than in rats with Schwann cell transplantation alone. The results demonstrated that lower extremity motor function and neurophysiological function were better in rats treated with edaravone and Schwann cells than in rats with Schwann cell transplantation only. These data confirmed that Schwann cell transplantation combined with edaravone injection promoted the regeneration of nerve fibers of rats with spinal cord injury and improved neurological function.

Anti-tumor effects of 125I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice

International Nuclear Information System (INIS)

Xiao Zhongdi; Liang Chunlin; Zhang Guoli; Jing Yue; Zhang Yucheng; Gai Baodong

2011-01-01

Objective: To study the anti-tumor effects of 125 I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice and clarify their anti-tumor mechanisms. Methods 120 nude mice transplantated with human breast cancer cells MCF-7 were randomly divided into 3 groups (n=40): 125 I radioactive particles implanted group, non-radioactive particles implanted group and non-particles implanted group. The articles were implanted into mice according to Pairs system principle. The expressions of Fas mRNA and protein and the activaties of caspase-3 and caspase-8 enzyme were detected by RT-PCR and Western blotting. The changes of cell cycle were detected by flow cytometry. Results: Compared with non-radioactive particles implanted group and non-particles implanted group, the size of cancer tissues in 125 I radioactive particles implanted group was reduced significantly (P 0 /G 1 phase was significantly increased (P 125 I radioactive particles into transplantated tumor model of human breast cancer cells can kill tumor cells, inhibit the growth cycle of tumor cells and induce the apoptosis of tumor cells in nude mice. (authors)

Cancer of rat ovaries: Sertoli cell or granulosa-theca cell tumours

International Nuclear Information System (INIS)

Knowles, J.F.

1983-01-01

The effects of X-radiation (0-1.25 Gy) given 24 hours after neonatal injections of the carcinogen ethyl nitrosourea (ENU) (0-10 mg/kg) in female rats were studied. Twelve out of 118 rats bore single ovarian tumours. A substantial excess of ovarian tumours occurred in the rats given 4 mg/kg ENU and 1.25 GY X-rays but not in others given ENU alone, radiation alone or 10 mg/kg ENU and 1.25 Gy. The tumours were all found in old rats (657-1085 days). In all of the tumours the presence of tubular formations suggested a diagnosis of ovarian Sertoli cell tumour. In two tumours, only a few tubular structures were seen and fibrous stromal tissue predominated, suggesting a diagnosis of granulosa-theca cell tumour. All other tumours were a mixture of both elements. (U.K.)

Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

International Nuclear Information System (INIS)

Kim, Beom-Su; Kim, Jin Seong; Park, Young Min; Choi, Bo-Young; Lee, Jun

2013-01-01

Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 10 16 ions/cm 2 was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation improved

Enhanced osteogenic activity of poly ether ether ketone using calcium plasma immersion ion implantation.

Science.gov (United States)

Lu, Tao; Qian, Shi; Meng, Fanhao; Ning, Congqin; Liu, Xuanyong

2016-06-01

As a promising implantable material, poly ether ether ketone (PEEK) possesses similar elastic modulus to that of cortical bones yet suffers from bio-inertness and poor osteogenic properties, which limits its application as orthopedic implants. In this work, calcium is introduced onto PEEK surface using calcium plasma immersion ion implantation (Ca-PIII). The results obtained from scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirm the modified layer with varying contents of calcium are formed on PEEK surfaces. Water contact angle measurements reveal the increasing hydrophobicity of both Ca-PIII treated surfaces. In vitro cell adhesion, viability assay, alkaline phosphatase activity and collagen secretion analyses disclose improved the adhesion, proliferation, and osteo-differentiation of rat bone mesenchymal stem cells (bMSCs) on Ca-PIII treated surfaces. The obtained results indicate that PEEK surface with enhanced osteogenic activity can be produced by calcium incorporation. Copyright © 2016 Elsevier B.V. All rights reserved.

Transcription factor and bone marrow stromal cells in osseointegration of dental implants

Directory of Open Access Journals (Sweden)

SG Yan

2018-05-01

Full Text Available Titanium implants are widely used in dental clinics and orthopaedic surgery. However, bone formation surrounding the implant is relatively slow after inserting the implant. The current study assessed the effects of bone marrow stromal cells (BMSCs with forced expression of special AT-rich sequence-binding protein 2 (SATB2 on the osseointegration of titanium implants. To determine whether SATB2 overexpression in BMSCs can enhance the osseointegration of implants, BMSCs were infected with the retrovirus encoding Satb2 (pBABE-Satb2 and were locally applied to bone defects before implanting the titanium implants in the mouse femur. Seven and twenty-one days after implantation, the femora were isolated for immunohistochemical (IHC staining, haematoxylin eosin (H&E staining, real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR, and micro-computed tomography (μCT analysis. IHC staining analysis revealed that SATB2-overexpressing BMSCs were intensely distributed in the bone tissue surrounding the implant. Histological analysis showed that SATB2-overexpressing BMSCs significantly enhanced new bone formation and bone-to-implant contact 3 weeks after implantation. Real-time qRT-PCR results showed that the local delivery of SATB2-overexpressing BMSCs enhanced expression levels of potent osteogenic transcription factors and bone matrix proteins in the implantation sites. μCT analysis demonstrated that SATB2-overexpressing BMSCs significantly increased the density of the newly formed bone surrounding the implant 3 weeks post-operatively. These results conclude that local delivery of SATB2-overexpressing BMSCs significantly accelerates osseointegration of titanium implants. These results provide support for future pharmacological and clinical applications of SATB2, which accelerates bone regeneration around titanium implants.

Metallic ion content and damage to the DNA in oral mucosa cells patients treated dental implants.

Science.gov (United States)

López-Jornet, Pía; Perrez, Francisco Parra; Calvo-Guirado, José Luis; Ros-Llor, Irene; LLor-Ros, Irene; Ramírez-Fernández, Piedad

2014-07-01

The aim of this study was to assess the potential genotoxicity of dental implants, evaluating biomarkers of DNA damage (micronuclei and/or nuclear buds), cytokinetic defects (binucleated cells) and the presence of trace metals in gingival cells of patients with implants, comparing these with a control group. A total of 60 healthy adults (30 patients with dental implants and 30 control patients without) were included in the study. Medical and dental histories were made for each including life-style factors. Genotoxicity effects were assessed by micronucleus assays in the gingival epithelial cells of each patient; 1,000 epithelial cells were analyzed, evaluating the frequency of micronucleated cells and other nuclear anomalies. The concentration of metals (Al(27), Ag(107), Co (59), Cr (52), Cu(63), Fe(56), Sn(118), Mn(55), Mo(92), Ni(60), Pb(208), Ti(47)) were assayed by means of coupled plasma-mass spectrophotometry (ICP-MS). The frequency of micronuclei in the patient group with implants was higher than in the control group but without statistically significant differences (P > 0.05). Similar results were found for binucleated cells and nuclear buds (P > 0.05). For metals assayed by ICP-MS, significant differences were found for Ti(47) (P ≤ 0.045). Univariate analysis identified a significant association between the presence of micronuclei and age. Dental implants do not induce DNA damage in gingival cells, the slight effects observed cannot be indicated as biologically relevant.