Chronic Orbital Inflammation Associated to Hydroxyapatite Implants in Anophthalmic Sockets

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Alicia Galindo-Ferreiro

2017-12-01

Full Text Available Purpose: We report 6 patients who received a hydroxyapatite (HA orbital implant in the socket and developed chronic orbital inflammation unresponsive to conventional medical therapy. Case Reports: We assisted 6 cases (4 males, 2 females who received an HA orbital implant in the socket between 2015 and 2016 at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia, and developed chronic orbital inflammation with chronic discharge, redness, and pain (onset from weeks to over 2 decades after surgery. Computed tomography evaluation indicated inflammation in the orbital tissues, and histological examination showed a foreign body granulomatous reaction mainly localized around and blanching the HA implant. The condition was unresponsive to usual medical treatment and was resolved immediately after implant removal. Conclusions: Chronic inflammation can occur decades after placement of an HA implant in the orbit and can be successfully treated with implant removal.

Thin hydroxyapatite surface layers on titanium produced by ion implantation

CERN Document Server

Baumann, H; Bilger, G; Jones, D; Symietz, I

2002-01-01

In medicine metallic implants are widely used as hip replacement protheses or artificial teeth. The biocompatibility is in all cases the most important requirement. Hydroxyapatite (HAp) is frequently used as coating on metallic implants because of its high acceptance by the human body. In this paper a process is described by which a HAp surface layer is produced by ion implantation with a continuous transition to the bulk material. Calcium and phosphorus ions are successively implanted into titanium under different vacuum conditions by backfilling oxygen into the implantation chamber. Afterwards the implanted samples are thermally treated. The elemental composition inside the implanted region was determined by nuclear analysis methods as (alpha,alpha) backscattering and the resonant nuclear reaction sup 1 H( sup 1 sup 5 N,alpha gamma) sup 1 sup 2 C. The results of X-ray photoelectron spectroscopy indicate the formation of HAp. In addition a first biocompatibility test was performed to compare the growing of m...

Design of an Implantable Device for Ocular Drug Delivery

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Jae-Hwan Lee

2012-01-01

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

Mechanical failure of hydroxyapatite-coated titanium and cobalt-chromium-molybdenum alloy implants. An animal study

DEFF Research Database (Denmark)

Nimb, L; Gotfredsen, K; Steen Jensen, J

1993-01-01

Defects in the hydroxyapatite (HA) ceramic coatings applied to metallic implant systems may occur at the time of insertion or at the time of in vivo loading. However, defects may also occur with time because of interaction with physiological fluids. A canine study was performed to make a histolog......Defects in the hydroxyapatite (HA) ceramic coatings applied to metallic implant systems may occur at the time of insertion or at the time of in vivo loading. However, defects may also occur with time because of interaction with physiological fluids. A canine study was performed to make...

Accelerator based synthesis of hydroxyapatite by MeV ion implantation

International Nuclear Information System (INIS)

Rautray, Tapash R.; Narayanan, R.; Kwon, Tae-Yub; Kim, Kyo-Han

2010-01-01

Accelerator based MeV ion implantation of Ca 2+ and P 2+ into the titanium substrate to form hydroxyapatite (HA) has been carried out. Calcium hydroxide was formed after heating the calcium implanted titanium in air at 80 o C for 3 h. Upon subsequent annealing for 5 min at 600 o C HA was formed on the surface. Penetration depth of the HA layer in this method is much higher as compared to keV ion implantation. By elemental analysis, Ca/P ratio of the HA was found to be 1.76 which is higher than the ideal 1.67. This higher Ca/P ratio is attributed to the higher penetration depth of the MeV technique used.

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

The psychosocial benefits of secondary hydroxyapatite orbital implant insertion and prosthesis wearing for patients with anophthalmia.

Science.gov (United States)

Wang, Junming; Zhang, Hong; Chen, Wei; Li, Guigang

2012-01-01

Anophthalmia is associated with a range of psychosocial difficulties and hydroxyapatite orbital implant insertion and prosthesis wearing is the predominant rehabilitation therapy for anophthalmia. However, few articles have compared preoperative and postoperative psychosocial outcomes using standardized questionnaires. This study aimed to investigate the psychosocial benefits of hydroxyapatite orbital implant insertion and prosthesis wearing in this patient population. In all, 36 participants were tested preoperatively and 6-months postoperatively using standardized measures of anxiety and depression (Hospital Anxiety and Depression Scale), social anxiety and social avoidance (Derriford Appearance Scale-Short Form), and quality of life (World Health Organization Quality of Life Scale-Short Form). Before treatment, levels of depression were comparable with population norms; however, levels of general anxiety were slightly raised, levels of social anxiety, social avoidance, and quality of life were significantly poorer than population norms. Treatment resulted in significant improvement in psychosocial adjustment with improvements in all study variables for the participant group as a whole. Hydroxyapatite orbital implant insertion and prosthesis wearing offers significant improvements in psychological and physical functioning for patients with anophthalmia.

Hydroxyapatite implants with designed internal architecture.

Science.gov (United States)

Chu, T M; Halloran, J W; Hollister, S J; Feinberg, S E

2001-06-01

Porous hydroxyapatite (HA) has been used as a bone graft material in the clinics for decades. Traditionally, the pores in these HAs are either obtained from the coralline exoskeletal patterns or from the embedded organic particles in the starting HA powder. Both processes offer very limited control on the pore structure. A new method for manufacturing porous HA with designed pore channels has been developed. This method is essentially a lost-mold technique with negative molds made with Stereolithography and a highly loaded curable HA suspension as the ceramic carrier. Implants with designed channels and connection patterns were first generated from a Computer-Aided-Design (CAD) software and Computer Tomography (CT) data. The negative images of the designs were used to build the molds on a stereolithography apparatus with epoxy resins. A 40 vol% HA suspension in propoxylated neopentyl glycol diacrylate (PNPGDA) and iso-bornyl acrylate (IBA) was formulated. HA suspension was cast into the epoxy molds and cured into solid at 85 degrees C. The molds and acrylate binders were removed by pyrolysis, followed by HA green body sintering. With this method, implants with six different channel designs were built successfully and the designed channels were reproduced in the sintered HA implants. The channels created in the sintered HA implants were between 366 microm and 968 microm in diameter with standard deviations of 50 microm or less. The porosity created by the channels were between 26% and 52%. The results show that HA implants with designed connection pattern and well controlled channel size can be built with the technique developed in this study. Copyright 2001 Kluwer Academic Publishers

Effects of phacoemulsification combined with intraocular lens implantation on ocular surface

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Ming Li

2013-10-01

Full Text Available AIM: To explore the changes of ocular surface after phacoemulsification combined with intraocular lens implantation. METHODS: Totally 78 cases of 78 eyes with age-related cataract were collected from August 2011 to October 2012, and they underwent corneal incision phacoemulsification combined with intraocular lens implantation. The score of dry eye symptoms; tear breakup time(BUT; Schirmer Ⅰ test(SⅠtand corneal fluorescein staining were observed and recorded in 3 days before, 1 day, 1 week, 1 month, 3 and 6 months after surgery respectively. The results were analyzed statistically. RESULTS: All the subjects complained of dry eye within 1 week after surgery. Compared with 3 days before the surgery, the corneal fluorescein staining increased and the amount of tear secretion reduced statistically significant in 1 day, 1 week and 1 month(PPP>0.05, and lasted to 3 months later. CONCLUSION: Phacoemulsification combined with intraocular lens implantation has obvious effect on the ocular surface to some extent. Preventions and treatment should be taken clinically.

Bilateral Ocular Decompression Retinopathy after Ahmed Valve Implantation for Uveitic Glaucoma

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Javier Flores-Preciado

2016-11-01

Full Text Available Case Report: We report the case of a 29-year-old man who underwent Ahmed valve implantation in both eyes as treatment for uveitic glaucoma, subsequently presenting with bilateral ocular decompression retinopathy in the postoperative period. Discussion: Ocular decompression retinopathy is a rare complication of filtering surgery in patients with glaucoma; however, the course is benign in most cases, with spontaneous resolution of bleedings and improvement of visual acuity.

Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

Energy Technology Data Exchange (ETDEWEB)

Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Herath, H.M.T.U. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Premachandra, T.N. [Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Ranasinghe, C.S.K. [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.P.V.J. [Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Rajapakse, R.M.G., E-mail: rmgr@pdn.ac.lk [Department of Chemistry, Faculty of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Postgraduate Institute of Science, University of Peradeniya, 20400 Peradeniya (Sri Lanka); Edirisinghe, Mohan; Mahalingam, S. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Bandara, I.M.C.C.D. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia); Singh, Sanjleena [Central Analytical Research Facility, Institute of Future Environments, Queensland University of Technology, 2 George Street, Brisbane 4001, QLD (Australia)

2016-06-01

Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO{sub 2} thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO{sub 2} thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

International Nuclear Information System (INIS)

Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Chathuranga Senarathna, K.G.; Herath, H.M.T.U.; Premachandra, T.N.; Ranasinghe, C.S.K.; Rajapakse, R.P.V.J.; Rajapakse, R.M.G.; Edirisinghe, Mohan; Mahalingam, S.; Bandara, I.M.C.C.D.; Singh, Sanjleena

2016-01-01

Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO_2 thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. - Highlights: • Colloidal hydroxyapatite nanorods are prepared by a novel method. • Surfaces of titanium metal plates are modified by self-forming TiO_2 thin-films. • Prostheses are prepared by coating hydroxyapatite on surface modified Ti metal. • Bioactivity and noncytotoxicity are increased with surface modifications.

Influence of the zinc and manganese doping on the kinetics of resorption of a hydroxyapatite implant and study on matrix effects in the used P.I.X.E. nuclear method; Influence du dopage en zinc et en manganese sur la cinetique de resorption d`un implant d`hydroxyapatite et etude des effets de matrice dans la methode nucleaire P.I.X.E. utilisee

Energy Technology Data Exchange (ETDEWEB)

Jallot, E.

1997-01-16

In this work we study hydroxyapatite, hydroxyapatite doped with zinc or manganese and the compound of 75% hydroxyapatite, 25% tricalcic phosphate. The ceramics were implanted in the cortical femur of sheep. The global evolution of mineral concentrations in the implants with the time after implantation was studied by neutronic radioactivation. We studied matrix effects in P.I.X.E. (Particles Induced X-rays Emission) with Alpha parameter method. By measurements at two different energies, we determine a correction factor of the slowing down of incident protons and of the X rays absorption in matrix. So, the P.I.X.E. analysis allow us a scanning of mineral concentrations at the bone-implant interface at different time after implantation. The transformation of the hydroxyapatite matrix has been studied by X-rays by X-rays diffraction. (author).

Converted marine coral hydroxyapatite implants with growth factors: In vivo bone regeneration

Energy Technology Data Exchange (ETDEWEB)

Nandi, Samit K., E-mail: samitnandi1967@gmail.com [Department of Veterinary Surgery and Radiology, West Bengal University of Animal and Fishery Sciences, Kolkata (India); Kundu, Biswanath, E-mail: biswa_kundu@rediffmail.com [Bioceramics and Coating Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Mukherjee, Jayanta [Institute of Animal Health and Veterinary Biologicals, Kolkata (India); Mahato, Arnab; Datta, Someswar; Balla, Vamsi Krishna [Bioceramics and Coating Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India)

2015-04-01

Herein we report rabbit model in vivo bone regeneration of hydrothermally converted coralline hydroxyapatite (HCCHAp) scaffolds without (group I) and with growth factors namely insulin like growth factor-1 (IGF-1) (group II) and bone morphogenetic protein-2 (BMP-2) (group III). All HCCHAp scaffolds have been characterized for phase purity and morphology before implantation. Calcined marine coral was hydrothermally converted using a mineralizer/catalyst to phase pure HAp retaining original pore structure and geometry. After sintering at 1250 °C, the HCCHAp found to have ~ 87% crystallinity, 70–75% porosity and 2 ± 0.5 MPa compressive strength. In vitro growth factor release study at day 28 revealed 77 and 98% release for IGF-1 and BMP-2, respectively. The IGF-1 release was more sustained than BMP-2. In vivo bone healing of different groups was compared using chronological radiology, histological evaluations, scanning electron microscopy and fluorochrome labeling up to 90 days of implantation. In vivo studies showed substantial reduction in radiolucent zone and decreased radiodensity of implants in group II followed by group III and group I. These observations clearly suggest in-growth of osseous tissue, initiation of bone healing and complete union between implants and natural bone in group II implants. A statistical score sheet based on histological observations showed an excellent osseous tissue formation in group II and group III scaffolds and moderate bone regeneration in group I scaffolds. - Highlights: • In vivo bone regeneration of hydrothermally converted coralline hydroxyapatite • Scaffolds with and without growth factors (IGF-1 and BMP-2) • In vitro drug release was more sustained for IGF-1 than BMP-2. • Growth factor significantly improved osseous tissue formation of implanted scaffold. • Established through detailed statistical score sheet from histological observations.

Converted marine coral hydroxyapatite implants with growth factors: In vivo bone regeneration

International Nuclear Information System (INIS)

Nandi, Samit K.; Kundu, Biswanath; Mukherjee, Jayanta; Mahato, Arnab; Datta, Someswar; Balla, Vamsi Krishna

2015-01-01

Herein we report rabbit model in vivo bone regeneration of hydrothermally converted coralline hydroxyapatite (HCCHAp) scaffolds without (group I) and with growth factors namely insulin like growth factor-1 (IGF-1) (group II) and bone morphogenetic protein-2 (BMP-2) (group III). All HCCHAp scaffolds have been characterized for phase purity and morphology before implantation. Calcined marine coral was hydrothermally converted using a mineralizer/catalyst to phase pure HAp retaining original pore structure and geometry. After sintering at 1250 °C, the HCCHAp found to have ~ 87% crystallinity, 70–75% porosity and 2 ± 0.5 MPa compressive strength. In vitro growth factor release study at day 28 revealed 77 and 98% release for IGF-1 and BMP-2, respectively. The IGF-1 release was more sustained than BMP-2. In vivo bone healing of different groups was compared using chronological radiology, histological evaluations, scanning electron microscopy and fluorochrome labeling up to 90 days of implantation. In vivo studies showed substantial reduction in radiolucent zone and decreased radiodensity of implants in group II followed by group III and group I. These observations clearly suggest in-growth of osseous tissue, initiation of bone healing and complete union between implants and natural bone in group II implants. A statistical score sheet based on histological observations showed an excellent osseous tissue formation in group II and group III scaffolds and moderate bone regeneration in group I scaffolds. - Highlights: • In vivo bone regeneration of hydrothermally converted coralline hydroxyapatite • Scaffolds with and without growth factors (IGF-1 and BMP-2) • In vitro drug release was more sustained for IGF-1 than BMP-2. • Growth factor significantly improved osseous tissue formation of implanted scaffold. • Established through detailed statistical score sheet from histological observations

Surgical pitfalls with custom-made porous hydroxyapatite cranial implants

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Bruno Zanotti

2015-03-01

Full Text Available Aim: Cranioplasty implants are used primarily in cases of surgical cranial decompression following pathological elevations of intracranial pressure. Available bone substitutes include porous hydroxyapatite (HA and polymethylmethacrylate. Whichever material is used, however, prosthetic cranial implants are susceptible to intra- and postsurgical complications and even failure. The aim of this study was to investigate such occurrences in HA cranioplasty implants, seeking not only to determine the likely causes (whether correlated or not with the device itself but also, where possible, to suggest countermeasures. Methods: We analyzed information regarding failures or complications reported in postmarketing surveillance and clinical studies of patients treated worldwide with custom-made HA cranial implants (Custom Bone Service Fin-Ceramica Faenza, Italy in the period 1997-2013. Results: The two most common complications were implant fractures (84 cases, 2.9% of the total fitted and infections (51 cases, 1.77%. Conclusion: Although cranioplasties are superficial and not difficult types of surgery, and use of custom-made implants are often considered the "easy" option from a surgical perspective, these procedures are nonetheless plagued by potential pitfalls. If performed well they yield more than satisfactory results from the points of view of both the patient and surgeon, but lack of appropriate care can open the door to numerous potential sources of failure, which can compromise-even irreparably-the ability to heal.

Improved cell viability and hydroxyapatite growth on nitrogen ion-implanted surfaces

Science.gov (United States)

Shafique, Muhammad Ahsan; Murtaza, G.; Saadat, Shahzad; Uddin, Muhammad K. H.; Ahmad, Riaz

2017-08-01

Stainless steel 306 is implanted with various doses of nitrogen ions using a 2 MV pelletron accelerator for the improvement of its surface biomedical properties. Raman spectroscopy reveals incubation of hydroxyapatite (HA) on all the samples and it is found that the growth of incubated HA is greater in higher ion dose samples. SEM profiles depict uniform growth and greater spread of HA with higher ion implantation. Human oral fibroblast response is also found consistent with Raman spectroscopy and SEM results; the cell viability is found maximum in samples treated with the highest (more than 300%) dose. XRD profiles signified greater peak intensity of HA with ion implantation; a contact angle study revealed hydrophilic behavior of all the samples but the treated samples were found to be lesser hydrophilic compared to the control samples. Nitrogen implantation yields greater bioactivity, improved surface affinity for HA incubation and improved hardness of the surface.

Dental implants coated with laser deposited hydroxyapatite films - physical properties and in-vivo study

Czech Academy of Sciences Publication Activity Database

Jelínek, Miroslav; Dostálová, T.; Himmlová, L.; Grivas, Ch.; Fotakis, C.

2002-01-01

Roč. 374, - (2002), s. 599-604 ISSN 1058-725X Institutional research plan: CEZ:AV0Z1010914 Keywords : laser deposition * thin films * implants * hydroxyapatite * in-vivo tests Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.457, year: 2002

Comparison of titanium mesh implants with PLA-hydroxyapatite coatings for maxillofacial cancer reconstruction

Science.gov (United States)

Tverdokhlebov, S. I.; Choinzonov, E. L.; Kolokolova, O. V.; Cherdyntseva, N. V.

2016-08-01

Since 2013 physics of TPU and oncologists from the TCRI with participation of the "ConMet" company (Moscow) and the "Sintel" company (Tomsk Special Economic Zone resident) have been working on the theme entitled "Development of the composite implants for reconstructive surgery of a craniofacial areas of the traumatological and oncological patients" supported with the Federal Program "R&D, part 1.3". The goal was to develop the maxillo-facial implants on the basis of the transformable titanium mesh with PLA & hydroxyapatite coating. According to the Contract No. 14.578.21.0031, the team of developers had to start supplying these advanced implants to the industrial partners up to 2017. This research was supported with the preliminary market researches by the ISPMS SB RAS and the TP "MF". The stages of preliminary market researches were: 1) research of the Worldwide CMF market; 2) forecasting the BRIC CMF market up to 2020; 3) the total Russian market (epidemiology) estimation as a sum of official calculations and statistics; 4) looking for the best foreign analogue prices, comparing their and our implant properties; 5) search for the best Russian analogues; 6) the investigation of the world patent database Espacenet for the last years, and finding the owners and applicants of patents of CMF osteosynthesis plates on the basis of titanium coated with PLA & hydroxyapatite; 7) comparison of the domestic implants, and making conclusions. Several variants of the meshes have got the equal quality with the best foreign and Russian implants. The closest analogues were titanium, polyethylene, PEEK composite meshes suited to the patient shape by the Synthes company in 2014, and the only hybrid titanium "Grey" implant with layers of gelatin, dextran, collagen, HAP & BMP-2 was found. This implant was produced by Russian institution, and it was mentioned in the report on clinical trials by L.A. Pavlova et al., 2014 [1]. There are no manufacturers of the coated implants in Russia

Hydroxyapatite coatings for biomedical applications

CERN Document Server

Zhang, Sam

2013-01-01

Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

A three-dimensional finite element study on the effect of hydroxyapatite coating thickness on the stress distribution of the surrounding dental implant-bone interface

Directory of Open Access Journals (Sweden)

Hadi Asgharzadeh Shirazi

2014-06-01

Full Text Available   Background and Aims: Hydroxyapatite coating has allocated a special place in dentistry due to its biocompatibility and bioactivity. The purpose of this study was to evaluate the relation between the hydroxyapatite thickness and stress distribution by using finite element method.   Materials and Methods: In this paper, the effect of hydroxyapatite coating thickness on dental implants was studied using finite element method in the range between 0 to 200 microns. A 3D model including one section of mandible bone was modeled by a thick layer of cortical surrounding dense cancellous and a Nobel Biocare commercial brand dental implant was simulated and analyzed under static load in the Abaqus software.   Results The diagram of maximum von Mises stress versus coating thickness was plotted for the cancellous and cortical bones in the range between 0 to 200 microns. The obtained results showed that the magnitude of maximum von Mises stress of bone decreased as the hydroxyapatite coating thickness increased. Also, the thickness of coating exhibited smoother stress distribution and milder variations of maximum von Mises stress in a range between 60 to 120 microns.   Conclusion: In present study, the stress was decreased in the mandible bone where hydroxyapatite coating was used. This stress reduction leads to a faster stabilization and fixation of implant in the mandible bone. Using hydroxyapatite coating as a biocompatible and bioactive material could play an important role in bone formation of implant- bone interface.

Influence of the zinc and manganese doping on the kinetics of resorption of a hydroxyapatite implant and study on matrix effects in the used P.I.X.E. nuclear method

International Nuclear Information System (INIS)

Jallot, E.

1997-01-01

In this work we study hydroxyapatite, hydroxyapatite doped with zinc or manganese and the compound of 75% hydroxyapatite, 25% tricalcic phosphate. The ceramics were implanted in the cortical femur of sheep. The global evolution of mineral concentrations in the implants with the time after implantation was studied by neutronic radioactivation. We studied matrix effects in P.I.X.E. (Particles Induced X-rays Emission) with Alpha parameter method. By measurements at two different energies, we determine a correction factor of the slowing down of incident protons and of the X rays absorption in matrix. So, the P.I.X.E. analysis allow us a scanning of mineral concentrations at the bone-implant interface at different time after implantation. The transformation of the hydroxyapatite matrix has been studied by X-rays by X-rays diffraction. (author)

Facial skeletal augmentation using hydroxyapatite cement.

Science.gov (United States)

Shindo, M L; Costantino, P D; Friedman, C D; Chow, L C

1993-02-01

This study investigates the use of a new calcium phosphate cement, which sets to solid, microporous hydroxyapatite, for facial bone augmentation. In six dogs, the supraorbital ridges were augmented bilaterally with this hydroxyapatite cement. On one side, the hydroxyapatite cement was placed directly onto the bone within a subperiosteal pocket. On the opposite side, the cement was contained within a collagen membrane tubule and then inserted into a subperiosteal pocket. The use of collagen tubules facilitated easy, precise placement of the cement. All implants maintained their original augmented height throughout the duration of the study. They were well tolerated without extrusion or migration, and there was no significant sustained inflammatory response. Histologic studies, performed at 3, 6, and 9 months revealed that when the cement was placed directly onto bone, progressive replacement of the implant by bone (osseointegration of the hydroxyapatite with the underlying bone) without a loss of volume was observed. In contrast, when the cement-collagen tubule combination was inserted, primarily a fibrous union was noted. Despite such fibrous union, the hydroxyapatite-collagen implant solidly bonded to the underlying bone, and no implant resorption was observed. Hydroxyapatite cement can be used successfully for the experimental augmentation of the craniofacial skeleton and may be applicable for such uses in humans.

Incorporation of different antibiotics into carbonated hydroxyapatite coatings on titanium implants, release and antibiotic efficacy

NARCIS (Netherlands)

Stigter, M.; Bezemer, J.M.; de Groot, K.; Layrolle, P.

2004-01-01

Carbonated hydroxyapatite (CHA) coatings were applied onto titanium implants by using a biomimetic precipitation method. Different antibiotics were incorporated into the CHA coatings and their release and efficacy against bacteria growth were studied in vitro. The following antibiotics were used

Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep

DEFF Research Database (Denmark)

Ding, Ming; Andreasen, Christina Møller; Dencker, Mads L.

2015-01-01

hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could...

Evaluation of Optical Quality: Ocular Scattering and Aberrations in Eyes Implanted with Diffractive Multifocal or Monofocal Intraocular Lenses.

Science.gov (United States)

Liao, Xuan; Lin, Jia; Tian, Jing; Wen, BaiWei; Tan, QingQing; Lan, ChangJun

2018-06-01

To compare objective optical quality, ocular scattering and aberrations of eyes implanted with an aspheric monofocal intraocular lens (IOL) or an aspheric apodized diffractive multifocal IOL three months after surgery. Prospective consecutive nonrandomized comparative cohort study. A total of 80 eyes from 57 cataract patients were bilaterally or unilaterally implanted with monofocal (AcrySof IQ SN60WF) or multifocal (AcrySof IQ ReSTOR SN6AD1) IOLs. Respectively, 40 eyes of 27 patients were implanted with monofocal IOLs, and 40 eyes of 30 patients were implanted with multifocal IOLs. Ocular high-order aberration (HOA) values were obtained using Hartmann-Shack aberrometer; objective scatter index (OSI), modulation transfer function (MTF) cutoff, Strehl ratio (SR), and contrast visual acuity OV at 100%, 20%, and 9% were measured using Objective Quality Analysis System II (OQAS II). Ocular aberrations performed similar in both groups (p > 0.05). However, significantly higher values of OSI and lower values of MTF cutoff, SR and OV were found in the SN6AD1 group (p < 0.05). Both ocular scattering and wave-front aberrations play essential role in retinal image quality, which may be overestimated when only aberrations were taken into account. Combining the effect of ocular scattering with HOA will result in a more accurate assessment of the visual and optical quality.

Spectral luminescent properties of bacteriochlorin and aluminum phthalocyanine nanoparticles as hydroxyapatite implant surface coating

Directory of Open Access Journals (Sweden)

Yu. S. Maklygina

2016-01-01

Full Text Available The development and the spectral research of unique coating as crystalline nanoparticles of IR photosensitizers were performed for the creation of hydroxyapatite implants with photobactericidal properties. It has been proved that by the interaction of nanoparticles covering implant with the polar solvent, which simulates the interaction of the implant with the biocomponents in vivo (fast proliferating and with immunocompetent cells, photosensitizers nanoparticles change the spectroscopic properties, becoming fluorescent and phototoxic. Thus, the developed coating based on crystalline photosensitizer nanoparticles with studied specific properties should have antibacterial, anti-inflammatory effect by the photodynamic treatment in the near implant area. This research opens the prospect of the local prevention of inflammatory and autoimmune reactions in the area of implantation. The results of the study suggest a promising this technology in order to create implants with photobactericidal properties.

Mechanistic investigation on microbial toxicity of nano hydroxyapatite on implant associated pathogens

Energy Technology Data Exchange (ETDEWEB)

Baskar, K. [Department of Biotechnology, University of Madras, Guindy Campus, Chennai, Tamil Nadu (India); Anusuya, T. [Department of Nanotechnology, SRM University, Kattankulathur, Tamil Nadu (India); Devanand Venkatasubbu, G., E-mail: gdevanandvenkatasubbu@gmail.com [Department of Nanotechnology, SRM University, Kattankulathur, Tamil Nadu (India)

2017-04-01

The use of atomic scale inorganic nanoparticles (NPs) to fight against pathogenic microorganisms is a recent trend in biomedical area which overcomes the limitations of organic compounds in terms of stability, shelf life and bioactivity. One such Calcium phosphate based biomaterial is hydroxyapatite (HA), considered as potential bioactive compound with excellent biocompatibility, osteointegrity and biodegradability. Osteomyelitis, the implant associated infection, is the major problem worldwide responsible for the majority of implant failure cases. Since HA is used as a coating material of implants, only few reports were available on its antimicrobial activity and cytotoxicity whereas no reports on its possible antimicrobial mechanism. In this present study, the HA-NPs were synthesized by wet chemical precipitation and were characterized using X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The synthesized HA-NPs were evaluated for antimicrobial activity against implant associated bacterial pathogens. The study also explores the mechanistic action of HA-NPs in killing of bacteria by determining the reactive oxygen species (ROS) generation, DNA fragmentation, Lactate dehydrogenase (LDH) leakage and cellular interaction. In addition the cytotoxicity of HA-NPs was determined by MTT assay and Fluorescence Microscopic analysis. The results revealed that, the synthesized HA-NPs showed good antibacterial activity for tested bacterial species and the possible antibacterial mechanism were due to the lack of membrane integrity and cytotoxic studies shows the concentration dependent changes in cell viability. - Highlights: • Antibacterial activity against Gram − ve bacterium • Mechanism of antibacterial activity is analyzed. • DNA fragmentation, growth curve, LDH, ROS are analyzed. • The mechanism is by damaging cell membrane. • Hydroxyapatite is biocompatible.

The effects of hydroxyapatite coating and bone allograft on fixation of loaded experimental primary and revision implants.

Science.gov (United States)

Søballe, Kjeld; Mouzin, Olivier R G; Kidder, Louis A; Overgaard, Søren; Bechtold, Joan E

2003-06-01

We used our established experimental model of revision joint replacement to examine the roles of hydroxyapatite coating and bone graft in improving the fixation of revision implants. The revision protocol uses the Søballe micromotion device in a preliminary 8-week period of implant instability for the presence of particulate polyethylene. During this procedure, a sclerotic endosteal bone rim forms, and a dense fibrous membrane is engendered, having macrophages with ingested polyethylene and high levels of inflammatory cytokines. At the time of revision after 8 weeks, the cavity is revised with either a titanium alloy (Ti) or a hydroxyapatite (HA) 6.0 mm plasma-sprayed implant, in the presence or absence of allograft packed into the initial 0.75 mm peri-implant gap. The contralateral limb is subjected to primary surgery with the same implant configuration, and serves as control. 8 implants were included in each of the 8 treatment groups (total 64 implants in 32 dogs). The observation period was 4 weeks after revision. Outcome measures are based on histomorphometry and mechanical pushout properties. The revision setting was always inferior to its primary counterpart. Bone graft improved the revision fixation in all treatment groups, as also did the HA coating. The sole exception was revision-grafted HA implants, which reached the same fixation as primary Ti and HA grafted implants. The revision, which was less active in general, seems to need the dual stimulation of bone graft and HA implant surface, to obtain the same level of fixation associated with primary implants. Our findings suggest that the combination of HA implant and bone graft may be of benefit in the clinical revision implant setting.

The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants in sheep

DEFF Research Database (Denmark)

Babiker, Hassan

  The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants IN SHEEP   Ph.D. Student, Hassan Babiker; Associate Professor, Ph.D. Ming Ding; Professor, dr.med., Soren Overgaard. Department of Orthopaedic Surgery, Odense University Hospital......, Odense, Denmark   Background: Hydroxyapatite and collagen composites (HA/coll) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effect of newly developed HA/coll-composites with and without bone marrow aspirate (BMA) in order to enhance the fixation...... of bone implants.   Materials and Methods: Titanium alloy implants were inserted into bilateral femoral condyles of 8 skeletally mature sheep, four in each sheep. The implant has a circumferential gap of 2 mm. The gap was filled with: HA/coll; HA/coll-BMA; autograft or allograft. Allograft was served...

Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite

DEFF Research Database (Denmark)

Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito

2016-01-01

Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its...... fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants...

Crystallization of modified hydroxyapatite on titanium implants

International Nuclear Information System (INIS)

Golovanova, O A; Izmailov, R R; Zaits, A V; Ghyngazov, S A

2016-01-01

Carbonated-hydroxyapatite (CHA) and Si-hydroxyapatite (Si-HA) precipitation have been synthesized from the model bioliquid solutions (synovial fluid and SBF). It is found that all the samples synthesized from the model solutions are single-phase and represent hydroxyapatite. The crystallization of the modified hydroxyapatite on alloys of different composition, roughness and subjected to different treatment techniques was investigated. Irradiation of the titanium substrates with the deposited biomimetic coating can facilitate further growth of the crystal and regeneration of the surface. (paper)

Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

Directory of Open Access Journals (Sweden)

Ievgen Volodymyrovych PYLYPCHUK

2014-09-01

Full Text Available Hydroxyapatite (HA has long been used as a coating material in the implant industry for orthopedic implant applications. HA is the natural inorganic constituent of bone and teeth. By coating titanium (base material of implant engineering because of its lightness and durability with hydroxyapatite, we can provide higher biocompatibility of titanium implants, according to HA ability to form a direct biochemical bond with living tissues. This article reports a biomimetic approach for coating hydroxyapatite with titanium A method of modifying the surface of titanium by organic modifiers (for creating functional groups on the surface, followed by formation "self-assembled" layer of biomimetic hydroxyapatite in simulated body fluid (SBF. FTIR and XPS confirmed the formation of hydroxyapatite coatings on titanium surface. Comparative study of the formation of HA on the surface of titanium plates modified by different functional groups: Ti(≡OH, Ti/(≡Si-OH and Ti/(≡COOH is conducted. It was found that the closest to natural stoichiometric hydroxyapatite Ca/P ratio was obtained on Ti/(≡COOH samples. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4974

Hydroxyapatite-diamondlike carbon nanocomposite films

International Nuclear Information System (INIS)

Narayan, Roger J.

2005-01-01

Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Conventional plasma-sprayed hydroxyapatite coatings demonstrate poor adhesion and poor mechanical integrity. We have developed hydroxyapatite-diamondlike carbon bilayer film. The diamondlike carbon interlayer serves to prevent metal ion release and improve adhesion of the hydroxyapatite film. These films were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, and microscratch adhesion testing. Based on the results of this study, hydroxyapatite-diamondlike carbon bilayers demonstrate promise for use in several orthopedic implants

Hydroxyapatite-diamondlike carbon nanocomposite films

Energy Technology Data Exchange (ETDEWEB)

Narayan, Roger J. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)]. E-mail: roger.narayan@mse.gatech.edu

2005-05-15

Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Conventional plasma-sprayed hydroxyapatite coatings demonstrate poor adhesion and poor mechanical integrity. We have developed hydroxyapatite-diamondlike carbon bilayer film. The diamondlike carbon interlayer serves to prevent metal ion release and improve adhesion of the hydroxyapatite film. These films were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, nanoindentation, and microscratch adhesion testing. Based on the results of this study, hydroxyapatite-diamondlike carbon bilayers demonstrate promise for use in several orthopedic implants.

The influence of radiation therapy on subperiosteal hydroxyapatite implants in rabbits

International Nuclear Information System (INIS)

Khateery, S.; Waite, P.D.; Lemons, J.E.

1991-01-01

Granular hydroxyapatite (HA) was implanted into subperiosteal pockets along both the right and left proximal tibias of 12 adult New Zealand white rabbits. The left extremities of 10 rabbits served as controls, whereas the right sides were irradiated with 2,250 rad in three doses over 5 days. The animals were killed at 1-week intervals starting at 2 weeks postirradiation. One half of each site was evaluated using standard histologic techniques while the other half was examined as a nondecalcified section. The quantity and the quality of new bone formation was determined using a rating scale and histomorphometric digitization. The results of this 4-month study showed that the amount of new bone formation around the HA granules was significantly greater in the irradiated sites. The irradiation produced no deleterious effects on the implant or the surrounding tissue areas

Hydroxyapatite coating on PEEK implants: Biomechanical and histological study in a rabbit model.

Science.gov (United States)

Durham, John W; Montelongo, Sergio A; Ong, Joo L; Guda, Teja; Allen, Matthew J; Rabiei, Afsaneh

2016-11-01

A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydroxyapatite-lignin composite as a metallic implant-bone tissue osseointegration improver: experimental study in dogs

Directory of Open Access Journals (Sweden)

Fabrício Luciani Valente

2015-01-01

Full Text Available The study aimed to evaluate biocompatibility, osteoconduction and osseointegration of a pasty composite of hydroxyapatite (20% and lignin (80% as a promoter of metal implant and bone tissue integration. An intramedullary Schanz pin was implanted in both tibias of fifteen bitches. In the left tibia, the pin was coated with the biomaterial at the time of surgery. Marrow cavity was also filled with the biomaterial. Right limb did not receive the biomaterial, then constituting the control group. Tibias were harvested from five animals at 8, 60 and 150 days after surgery; three of them were analyzed by histological and biomechanical assessment and the two remaining tibias by X-ray diffraction. Results showed that the biomaterial is biocompatible, with osteoconductivity and osseointegration properties. Histological analysis and diffractograms showed the presence of hydroxyapatite in samples in all periods, although the presence of organic material of low crystallinity was variable. There was no statistical difference in the forces required for removal of the biocompatibility, osteoconductivity and osseointegration, it was not able to promote a better intramedullary pin anchorage.

Fixation of Hydroxyapatite-Coated Revision Implants Is Improved by the Surgical Technique of Cracking the Sclerotic Bone Rim

Science.gov (United States)

Elmengaard, Brian; Bechtold, Joan E.; Chen, Xinqian; Søballe, Kjeld

2013-01-01

Revision joint replacement has poorer outcomes that have been associated with poorer mechanical fixation. We investigate a new bone-sparing surgical technique that locally cracks the sclerotic bone rim formed during aseptic loosening. We inserted 16 hydroxyapatite-coated implants bilaterally in the distal femur of eight dogs, using a controlled weight-bearing experimental model that replicates important features of a typical revision setting. At 8 weeks, a control revision procedure and a crack revision procedure were performed on contralateral implants. The crack procedure used a splined tool to perform a systematic local perforation of the sclerotic bone rim of the revision cavity. After 4 weeks, the hydroxyapatite-coated implants were evaluated for mechanical fixation by a push-out test and for tissue distribution by histomorphometry. The cracking revision procedure resulted in significantly improved mechanical fixation, significantly more bone ongrowth and bone volume in the gap, and reduced fibrous tissue compared to the control revision procedure. The study demonstrates that the sclerotic bone rim prevents bone ingrowth and promotes fixation by fibrous tissue. The effect of the cracking technique may be due to improved access to the vascular compartment of the bone. The cracking technique is a simple surgical method that potentially can improve the fixation of revision implants in sclerotic regions important for obtaining the fixation critical for overall implant stability. PMID:19148940

Bone integration capability of nanopolymorphic crystalline hydroxyapatite coated on titanium implants

Directory of Open Access Journals (Sweden)

Suzuki T

2012-02-01

Full Text Available Masahiro Yamada*, Takeshi Ueno*, Naoki Tsukimura, Takayuki Ikeda, Kaori Nakagawa, Norio Hori, Takeo Suzuki, Takahiro OgawaLaboratory of Bone and Implant Sciences, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA *These authors contributed equally to this workAbstract: The mechanism by which hydroxyapatite (HA-coated titanium promotes bone–implant integration is largely unknown. Furthermore, refining the fabrication of nanostructured HA to the level applicable to the mass production process for titanium implants is challenging. This study reports successful creation of nanopolymorphic crystalline HA on microroughened titanium surfaces using a combination of flame spray and low-temperature calcination and tests its biological capability to enhance bone–implant integration. Sandblasted microroughened titanium implants and sandblasted + HA-coated titanium implants were subjected to biomechanical and histomorphometric analyses in a rat model. The HA was 55% crystallized and consisted of nanoscale needle-like architectures developed in various diameters, lengths, and orientations, which resulted in a 70% increase in surface area compared to noncoated microroughened surfaces. The HA was free from impurity contaminants, with a calcium/phosphorus ratio of 1.66 being equivalent to that of stoichiometric HA. As compared to microroughened implants, HA-coated implants increased the strength of bone–implant integration consistently at both early and late stages of healing. HA-coated implants showed an increased percentage of bone–implant contact and bone volume within 50 µm proximity of the implant surface, as well as a remarkably reduced percentage of soft tissue intervention between bone and the implant surface. In contrast, bone volume outside the 50 µm border was lower around HA-coated implants. Thus, this study

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.

Natural History of Bone Response to Hydroxyapatite-Coated Hip Prostheses Implanted in Humans

OpenAIRE

Frayssinet, P.; Hardy, D.; Hanker, J. S.; Giammara, B. L.

1995-01-01

A series of 15 autopsied femurs containing hydroxyapatite- coated (HA-coated) prostheses was analysed histologically. Their implantation time ranged from 5 days up to 3 years. The coating thickness of some prostheses and the percentage of the coating in contact with bone at different levels were evaluated using an image analysis device. After the newly formed bone tissue had became mature, several bone morphotypes were identified at the coating contact. From the proximal to the distal part of...

Development of hydroxyapatite/polyvinyl alcohol bionanocomposite for prosthesis implants

Science.gov (United States)

Karthik, V.; Pabi, S. K.; Chowdhury, S. K. Roy

2018-02-01

Hydroxyapatite (Ca10(PO4)6(OH)2) has similar structural and chemical properties of natural bone mineral and hence widely used as a bone replacement substitute. Natural bone consists of hydroxyapatite and collagen. For mimicking the natural, in the present work, a sintered porous hydroxyapatite component has been vacuum impregnated with Polyvinyl alcohol (PVA), which has better properties like biocompatibility, biodegradability and water- solubility. Hydroxyapatite powders have been made into nanosize to reduce the melting point and hence the sintering temperature. In the present investigation high energy ball mill is used to produce nano-hydroxyapatite powders in bulk quantity by optimizing the milling parameters using stainless steel grinding media. Pellets of 10 mm diameter have been produced from nano- hydroxyapatite powders under different uniaxial compaction pressures. The pellets have been sintered to form porous compacts. The vacuum impregnation of sintered pallets with PVA solution of different strength has been done to find the optimum impregnation condition. Microhardness, compressive strength, wear loss and haemocompatibility of hydroxyapatite ceramics have been studied before and after impregnation of PVA. The nano- hydroxyapatite/PVA composites have superior mechanical properties and reduced wear loss than the non-impregnated porous nano-hydroxyapatite ceramics.

Hydroxyapatite nanocrystals functionalized with alendronate as bioactive components for bone implant coatings to decrease osteoclastic activity

Science.gov (United States)

Bosco, Ruggero; Iafisco, Michele; Tampieri, Anna; Jansen, John A.; Leeuwenburgh, Sander C. G.; van den Beucken, Jeroen J. J. P.

2015-02-01

The integration of bone implants within native bone tissue depends on periprosthetic bone quality, which is severely decreased in osteoporotic patients. In this work, we have synthesized bone-like hydroxyapatite nanocrystals (nHA) using an acid-base neutralization reaction and analysed their physicochemical properties. Subsequently, we have functionalized the nHA with alendronate (nHAALE), a well-known bisphosphonate drug used for the treatment of osteoporosis. An in vitro osteoclastogenesis test was carried out to evaluate the effect of nHAALE on the formation of osteoclast-like cells from monocytic precursor cells (i.e. RAW264.7 cell line) showing that nHAALE significantly promoted apoptosis of osteoclast-like cells. Subsequently, nHA and nHAALE were deposited on titanium disks using electrospray deposition (ESD), for which characterisation of the deposited coatings confirmed the presence of alendronate in nHAALE coatings with nanoscale thickness of about 700 nm. These results indicate that alendronate linked to hydroxyapatite nanocrystals has therapeutic potential and nHAALE can be considered as an appealing coating constituent material for orthopaedic and oral implants for application in osteoporotic patients.

In vitro and in vivo investigation of bisphosphonate-loaded hydroxyapatite particles for peri-implant bone augmentation.

Science.gov (United States)

Kettenberger, Ulrike; Luginbuehl, Vera; Procter, Philip; Pioletti, Dominique P

2017-07-01

Locally applied bisphosphonates, such as zoledronate, have been shown in several studies to inhibit peri-implant bone resorption and recently to enhance peri-implant bone formation. Studies have also demonstrated positive effects of hydroxyapatite (HA) particles on peri-implant bone regeneration and an enhancement of the anti-resorptive effect of bisphosphonates in the presence of calcium. In the present study, both hydroxyapatite nanoparticles (nHA) and zoledronate were combined to achieve a strong reinforcing effect on peri-implant bone. The nHA-zoledronate combination was first investigated in vitro with a pre-osteoclastic cell assay (RAW 264.7) and then in vivo in a rat model of postmenopausal osteoporosis. The in vitro study confirmed that the inhibitory effect of zoledronate on murine osteoclast precursor cells was enhanced by loading the drug on nHA. For the in vivo investigation, either zoledronate-loaded or pure nHA were integrated in hyaluronic acid hydrogel. The gels were injected in screw holes that had been predrilled in rat femoral condyles before the insertion of miniature screws. Micro-CT-based dynamic histomorphometry and histology revealed an unexpected rapid mineralization of the hydrogel in vivo through formation of granules, which served as scaffold for new bone formation. The delivery of zoledronate-loaded nHA further inhibited a degradation of the mineralized hydrogel as well as a resorption of the peri-implant bone as effectively as unbound zoledronate. Hyaluronic acid with zoledronate-loaded nHA, thanks to its dual effect on inducing a rapid mineralization and preventing resorption, is a promising versatile material for bone repair and augmentation. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

An improved biofunction of titanium for keratoprosthesis by hydroxyapatite-coating.

Science.gov (United States)

Dong, Ying; Yang, Jingxin; Wang, Liqiang; Ma, Xiao; Huang, Yifei; Qiu, Zhiye; Cui, Fuzhai

2014-03-01

Titanium framework keratoprosthesis has been commonly used in the severe corneal blindness, but the tissue melting occurred frequently around titanium. Since hydroxyapatite has been approved to possess a good tissue integration characteristic, nanostructured hydroxyapatite was coated on the surface of titanium through the aerosol deposition method. In this study, nanostructured hydroxyapatite coating was characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and auger electronic spectrometer. Biological evaluations were performed with rabbit cornea fibroblast in vitro and an animal model in vivo. The outcomes showed the coating had a grain-like surface topography and a good atomic mixed area with substrate. The rabbit cornea fibroblasts appeared a good adhesion on the surface of nanostructured hydroxyapatite in vitro. In the animal model, nanostructured hydroxyapatite-titanium implants were stably retained in the rabbit cornea, and by contrast, the corneal stroma became thinner anterior to the implants in the control. Therefore, our findings proved that nanostructured hydroxyapatite-titanium could not only provide an improved bond for substrate but also enhance the tissue integration with implants in host. As a promising material, nanostructured hydroxyapatite-titanium-based keratoprosthesis prepared by the aerosol deposition method could be utilized for the corneal blindness treatment.

Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces.

Science.gov (United States)

Wijesinghe, W P S L; Mantilaka, M M M G P G; Chathuranga Senarathna, K G; Herath, H M T U; Premachandra, T N; Ranasinghe, C S K; Rajapakse, R P V J; Rajapakse, R M G; Edirisinghe, Mohan; Mahalingam, S; Bandara, I M C C D; Singh, Sanjleena

2016-06-01

Preparation of hydroxyapatite coated custom-made metallic bone-implants is very important for the replacement of injured bones of the body. Furthermore, these bone-implants are more stable under the corrosive environment of the body and biocompatible than bone-implants made up of pure metals and metal alloys. Herein, we describe a novel, simple and low-cost technique to prepare biocompatible hydroxyapatite coated titanium metal (TiM) implants through growth of self-formed TiO2 thin-layer (SFTL) on TiM via a heat treatment process. SFTL acts as a surface binder of HA nanoparticles in order to produce HA coated implants. Colloidal HA nanorods prepared by a novel surfactant-assisted synthesis method, have been coated on SFTL via atomized spray pyrolysis (ASP) technique. The corrosion behavior of the bare and surface-modified TiM (SMTiM) in a simulated body fluid (SBF) medium is also studied. The highest corrosion rate is found to be for the bare TiM plate, but the corrosion rate has been reduced with the heat-treatment of TiM due to the formation of SFTL. The lowest corrosion rate is recorded for the implant prepared by heat treatment of TiM at 700 °C. The HA-coating further assists in the passivation of the TiM in the SBF medium. Both SMTiM and HA coated SMTiM are noncytotoxic against osteoblast-like (HOS) cells and are in high-bioactivity. The overall production process of bone-implant described in this paper is in high economic value. Copyright © 2016 Elsevier B.V. All rights reserved.

A study of the effect of low intensity laser therapy on the osseointegration of hydroxyapatite implants

International Nuclear Information System (INIS)

Rajab, A.A.

1999-01-01

Three significant developments over the last decade in the maxillofacial region have been the predictable use of dental implants, the employment of hydroxyapatite as an implant coating, with a potential for more rapid osseointegration, and the introduction of Low Intensity Laser Therapy (LILT) for the enhancement of healing. Implants, although proving a major advance in prosthetics have the disadvantage that loading has to be delayed for a period, which in the case of the mouth needs to be 3 - 6 months after insertion. Hydroxyapatite offers the possibility of a shortened period of delay. Low Intensity Laser Therapy (LILT) has been shown to accelerate the healing of bony fractures, both experimentally and clinically. This thesis sets out to evaluate whether LILT could enhance the process of osseointegration, particularly when used with ceramic hydroxyapatite implants in an animal model. If so, this could provide a future clinical combination which would allow earlier loading of hydroxyapatite coated dental implants and also their counterparts in femoral head replacement. There has been virtually no research work undertaken on this aspect. An animal research study has been undertaken to investigate the effect of LILT on the osseointegration of endosseous implants. HA ceramic implants were inserted in two different anatomical sites, namely the mandible and femur in 40 rabbits. The animals were divided into three groups, comprising a low energy laser group (25 J/cm 2 per treatment), a high energy group (125 J/cm 2 per treatment ) and a control group. Animals were sacrificed at four and twelve weeks, with equivalent numbers of representatives of the three groups. The evolved method of evaluation involved radiographic methods (plain x-ray, radiovisiography RVG and the innovative technique of x-ray microtomography XMT), mechanical push out testing (Instron machine) and histological examination (qualitative and quantitative histomorphometry). The conclusions of the study

Cementless Hydroxyapatite Coated Hip Prostheses

Science.gov (United States)

Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

2015-01-01

More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

Cementless Hydroxyapatite Coated Hip Prostheses

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Antonio Herrera

2015-01-01

Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

Histologic analysis of a retrieved hydroxyapatite-coated femoral prosthesis

DEFF Research Database (Denmark)

Søballe, K; Gotfredsen, K; Brockstedt-Rasmussen, H

1991-01-01

A hydroxyapatite-coated hip hemi-prosthesis was retrieved from a 98-year-old osteoporotic woman 12 weeks after implantation. Histologic analysis revealed bone and fibrous tissue almost evenly distributed around the surface of the implant circumference. Quantitative histologic analysis showed...... that 48% of the hydroxyapatite surface was covered by bone. Fibrous tissue covered 30% of the prosthetic surface, and 20% of the surface had no tissue coverage. Scanning electron microscopy showed direct contact without any clear boundary between the newly formed bone and the hydroxyapatite ceramic....

Development of implant/interconnected porous hydroxyapatite complex as new concept graft material.

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Kazuya Doi

Full Text Available BACKGROUND: Dental implant has been successfully used to replace missing teeth. However, in some clinical situations, implant placement may be difficult because of a large bone defect. We designed novel complex biomaterial to simultaneously restore bone and place implant. This complex was incorporated implant into interconnected porous calcium hydroxyapatite (IP-CHA. We then tested this Implant/IP-CHA complex and evaluated its effect on subsequent bone regeneration and implant stability in vivo. METHODOLOGY/PRINCIPAL FINDINGS: A cylinder-type IP-CHA was used in this study. After forming inside of the cylinder, an implant was placed inside to fabricate the Implant/IP-CHA complex. This complex was then placed into the prepared bone socket in the femur of four beagle-Labrador hybrid dogs. As a control, implants were placed directly into the femur without any bone substrate. Bone sockets were allowed to heal for 2, 3 and 6 months and implant stability quotients (ISQ were measured. Finally, tissue blocks containing the Implant/IP-CHA complexes were harvested. Specimens were processed for histology and stained with toluidine blue and bone implant contact (BIC was measured. The ISQs of complex groups was 77.8±2.9 in the 6-month, 72.0±5.7 in the 3-month and 47.4±11.0 in the 2-month. There was no significant difference between the 3- or 6-month complex groups and implant control groups. In the 2-month group, connective tissue, including capillary angiogenesis, was predominant around the implants, although newly formed bone could also be observed. While, in the 3 and 6-month groups, newly formed bone could be seen in contact to most of the implant surface. The BICs of complex groups was 2.18±3.77 in the 2-month, 44.03±29.58 in the 3-month, and 51.23±8.25 in the 6-month. Significant difference was detected between the 2 and 6-month. CONCLUSIONS/SIGNIFICANCE: Within the results of this study, the IP-CHA/implant complex might be able to achieve both

Antibacterial effects of silver-doped hydroxyapatite thin films sputter deposited on titanium

International Nuclear Information System (INIS)

Trujillo, Nathan A.; Oldinski, Rachael A.; Ma, Hongyan; Bryers, James D.; Williams, John D.; Popat, Ketul C.

2012-01-01

Since many orthopedic implants fail as a result of loosening, wear, and inflammation caused by repeated loading on the joints, coatings such as hydroxyapatite (HAp) on titanium with a unique topography have been shown to improve the interface between the implant and the natural tissue. Another serious problem with long-term or ideally permanent implants is infection. It is important to prevent initial bacterial colonization as existing colonies have the potential to become encased in an extracellular matrix polymer (biofilm) that is resistant to antibacterial agents. In this study, plasma-based ion implantation was used to examine the effects of pre-etching on plain titanium. Topographical changes to the titanium samples were examined and compared via scanning electron microscopy. Hydroxyapatite and silver-doped hydroxyapatite thin films were then sputter deposited on titanium substrates etched at − 700 eV. For silver-doped films, two concentrations of silver (∼ 0.5 wt.% and ∼ 1.5 wt.%) were used. Silver concentrations in the film were determined using energy dispersive X-ray spectroscopy. Hydroxyapatite film thicknesses were determined by measuring the surface profile using contact profilometry. Staphylococcus epidermidis and Pseudomonas aeruginosa adhesion studies were performed on plain titanium, titanium coated with hydroxyapatite, titanium coated with ∼ 0.5 wt.% silver-doped hydroxyapatite, and titanium coated with ∼ 1.5 wt.% silver-doped hydroxyapatite. Results indicate that less bacteria adhered to surfaces containing hydroxyapatite and silver; further, as the hydroxyapatite films delaminated, silver ions were released which killed bacteria in suspension. - Highlights: ► We have developed a combination of plasma-based ion implantation and ion beam sputter deposition technique. ► Silver-doped hydroxyapatite thin films on titanium were developed. ► The thin films showed the ability to control the concentration of silver that is doped within the

Effect of membranes and porous hydroxyapatite on healing in bone defects around titanium dental implants. An experimental study in monkeys

DEFF Research Database (Denmark)

Gotfredsen, K; Warrer, K; Hjørting-Hansen

1991-01-01

The purpose of the present study was to examine the effect of treating bony craters around titanium dental implant with polytetrafluoroethylene membranes (PTFE), with and without grafting of hydroxyapatite (HA), and with HA alone. 4 standardized bone defects were prepared in the alveolar ridge...

Characteristics of porous zirconia coated with hydroxyapatite

Indian Academy of Sciences (India)

However, porous hydroxyapatite bodies are mechanically weak and brittle, which makes shaping and implantation difficult. One way to solve this problem is to introduce a strong porous network onto which hydroxyapatite coating is applied. In this study, porous zirconia and alumina-added zirconia ceramics were prepared ...

Peculiarities of hydroxyapatite/nanodiamond composites as novel implants

International Nuclear Information System (INIS)

Pramatarova, L; Dimitrova, R; Pecheva, E; Spassov, T; Dimitrova, M

2007-01-01

Hydroxyapatite/detonation nanodiamond composites are created on silica glass and cover glass by simple soaking process in an open deposition type set-up. The supersaturated solution (simulated body fluid, SBF) is prepared in a way to resemble the composition of human blood plasma. The composite growth is carried out through the addition of detonation nanodiamond particles to the SBF. Scanning electron microscopy, X-ray diffraction and FTIR spectroscopy are used to determine the surface morphology and the structure of the hydroxyapatite /detonation nanodiamond composite layers. The applied methods provide evidence that the nanodiamond surface functional groups interact strongly with the biological solution. The detonation nanodiamond surface is chemically multifunctional (surface OH, C-O-H, C = C, C-O-C and C = O groups exist), so that the hydroxyapatite is grown both by physical adsorption and chemical interaction. The OH - groups are regarded to play an important role in the hydroxyapatite growth on a diamond's surface from SBF, as they charge it negatively and attract Ca 2+ ions, which in turn attract PO 4 3- ions, thus forming apatite nuclei

Decompression Retinopathy after ExPRESS Shunt Implantation for Steroid-Induced Ocular Hypertension: A Case Report

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Khawla Abu Samra

2011-01-01

Full Text Available Purpose. To present a unique case of decompression retinopathy after the implantation of ExPRESS drainage device. Method. A 25-year-old female patient underwent implantation of ExPRESS drainage device in the left eye for the management of steroid-induced ocular hypertension. Results. On the postoperative day one, best-corrected visual acuity in the left eye was 20/50. Fundus examination revealed diffuse intraretinal hemorrhages, some white-centered, throughout the retina. There was also marked tortuosity to the retinal vasculature and no evidence of choroidal effusion. Intravenous fluorescein angiography and indocyanine green did not contribute to the aetiopathogenesis. Conclusion. Decompression retinopathy can occur following the implantation of ExPRESS drainage device. It is very important to be aware of this complication in patients with relatively high intraocular pressure who is planned for filtration surgery, including the ExPRESS implant.

Valorization of Bone Waste of Saudi Arabia by Synthesizing Hydroxyapatite.

Science.gov (United States)

Amna, Touseef

2018-05-09

At present, hydroxyapatite is being frequently used for diverse biomedical applications as it possesses excellent biocompatibility, osteoconductivity, and non-immunogenic characteristics. The aim of the present work was to recycle bone waste for synthesis of hydroxyapatite nanoparticles to be used as bone extracellular matrix. For this reason, we for the first time utilized bio-waste of cow bones of Albaha city. The residual bones were utilized for the extraction of natural bone precursor hydroxyapatite. A facile scientific technique has been used to synthesize hydroxyapatite nanoparticles through calcinations of wasted cow bones without further supplementation of chemicals/compounds. The obtained hydroxyapatite powder was ascertained using physicochemical techniques such as XRD, SEM, FTIR, and EDX. These analyses clearly show that hydroxyapatite from native cow bone wastes is biologically and physicochemically comparable to standard hydroxyapatite, commonly used for biomedical functions. The cell viability and proliferation over the prepared hydroxyapatite was confirmed with CCk-8 colorimetric assay. The morphology of the cells growing over the nano-hydroxyapatite shows that natural hydroxyapatite promotes cellular attachment and proliferation. Hence, the as-prepared nano-hydroxyapatite can be considered as cost-effective source of bone precursor hydroxyapatite for bone tissue engineering. Taking into account the projected demand for reliable bone implants, the present research work suggested using environment friendly methods to convert waste of Albaha city into nano-hydroxyapatite scaffolds. Therefore, besides being an initial step towards accomplishment of projected demands of bone implants in Saudi Arabia, our study will also help in reducing the environmental burden by recycling of bone wastes of Albaha city.

Hydroxyapatite coating on cobalt alloys using electrophoretic deposition method for bone implant application

Science.gov (United States)

Aminatun; M, Shovita; I, Chintya K.; H, Dyah; W, Dwi

2017-05-01

Damage on bone due to osteoporosis and cancer triggered high demand for bone implant prosthesis which is a permanent implant. Thus, a prosthesis coated with hydroxyapatite (HA) is required because it is osteoconductive that can trigger the growth of osteoblast cells. The purpose of this study is to determine the optimum concentration of HA suspension in terms of the surface morphology, coating thickness, adhesion strength and corrosion rate resulting in the HA coating with the best characteristics for bone implant. Coating using electrophoretic deposition (EPD) method with concentrations of 0.02M, 0.04M, 0.06M, 0.08M, and 0.1M was performed on the voltage and time of 120V and 30 minutes respectively. The process was followed by sintering at the temperature of 900 °C for 10 minutes. The results showed that the concentration of HA suspension influences the thickness and the adhesion of layer of HA. The higher the concentration of HA-ethanol suspension the thicker the layer of HA, but its coating adhesion strength values became lower. The concentration of HA suspension of 0.04 M is the best concentration, with characteristics that meet the standards of the bone implant prosthesis. The characteristics are HA coating thickness of 199.93 ± 4.85 μm, the corrosion rate of 0.0018 mmpy and adhesion strength of 4.175 ± 0.716 MPa.

Discrete deposition of hydroxyapatite nanoparticles on a titanium implant with predisposing substrate microtopography accelerated osseointegration

International Nuclear Information System (INIS)

Nishimura, Ichiro; Huang Yuhong; Butz, Frank; Ogawa, Takahiro; Lin, Audrey; Wang, Chiachien Jake

2007-01-01

We report here a new versatile method to deposit discrete hydroxyapatite (HA) nanoparticles on a titanium (Ti) implant with predisposing substrate microtopography, which exhibited an unexpectedly robust biological effect. Commercially pure Ti substrates were treated with 3-aminopropyltriethoxysilane, on which HA nanoparticles (20 nm) were deposited and chemically bonded to TiO 2 . The HA deposition rate was linearly related to the treatment time and HA nanoparticles were deposited on up to 50% of the substrate surface. As a result, the discrete deposition of HA nanoparticles generated novel 20-40 nm nanotopography on the Ti substrate with microtopography that was smooth (turned) or roughened by double acid etching (DAE). The experimental implants with or without HA nanoparticles were surgically placed in rat femur and an implant push-in test was performed after two weeks of healing. The deposition of HA nanoparticles on the DAE surface increased the mechanical withstanding load by 129% and 782% as compared to the control DAE and turned implants, respectively. Micro-computed tomography-based 3D bone morphometry revealed equivalent bone volumes around the DAE implant with or without HA nanoparticles. These data suggest that the discrete deposition of HA nanoparticles accelerates the early osseointegration process, likely through increased shear bonding strengths

Discrete deposition of hydroxyapatite nanoparticles on a titanium implant with predisposing substrate microtopography accelerated osseointegration

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Ichiro [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Huang Yuhong [Chemat Technology, Incorporated, Northridge, CA (United States); Butz, Frank [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Ogawa, Takahiro [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Lin, Audrey [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States); Wang, Chiachien Jake [UCLA School of Dentistry, Weintraub Center for Reconstructive Biotechnology and Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, Los Angeles, CA (United States)

2007-06-20

We report here a new versatile method to deposit discrete hydroxyapatite (HA) nanoparticles on a titanium (Ti) implant with predisposing substrate microtopography, which exhibited an unexpectedly robust biological effect. Commercially pure Ti substrates were treated with 3-aminopropyltriethoxysilane, on which HA nanoparticles (20 nm) were deposited and chemically bonded to TiO{sub 2}. The HA deposition rate was linearly related to the treatment time and HA nanoparticles were deposited on up to 50% of the substrate surface. As a result, the discrete deposition of HA nanoparticles generated novel 20-40 nm nanotopography on the Ti substrate with microtopography that was smooth (turned) or roughened by double acid etching (DAE). The experimental implants with or without HA nanoparticles were surgically placed in rat femur and an implant push-in test was performed after two weeks of healing. The deposition of HA nanoparticles on the DAE surface increased the mechanical withstanding load by 129% and 782% as compared to the control DAE and turned implants, respectively. Micro-computed tomography-based 3D bone morphometry revealed equivalent bone volumes around the DAE implant with or without HA nanoparticles. These data suggest that the discrete deposition of HA nanoparticles accelerates the early osseointegration process, likely through increased shear bonding strengths.

Peculiarities of hydroxyapatite/nanodiamond composites as novel implants

Energy Technology Data Exchange (ETDEWEB)

Pramatarova, L [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences (Bulgaria); Dimitrova, R [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences (Bulgaria); Pecheva, E [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences (Bulgaria); Spassov, T [Sofia University, Faculty of Chemistry (Bulgaria); Dimitrova, M [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences (Bulgaria)

2007-12-15

Hydroxyapatite/detonation nanodiamond composites are created on silica glass and cover glass by simple soaking process in an open deposition type set-up. The supersaturated solution (simulated body fluid, SBF) is prepared in a way to resemble the composition of human blood plasma. The composite growth is carried out through the addition of detonation nanodiamond particles to the SBF. Scanning electron microscopy, X-ray diffraction and FTIR spectroscopy are used to determine the surface morphology and the structure of the hydroxyapatite /detonation nanodiamond composite layers. The applied methods provide evidence that the nanodiamond surface functional groups interact strongly with the biological solution. The detonation nanodiamond surface is chemically multifunctional (surface OH, C-O-H, C = C, C-O-C and C = O groups exist), so that the hydroxyapatite is grown both by physical adsorption and chemical interaction. The OH{sup -} groups are regarded to play an important role in the hydroxyapatite growth on a diamond's surface from SBF, as they charge it negatively and attract Ca{sup 2+} ions, which in turn attract PO{sub 4}{sup 3-} ions, thus forming apatite nuclei.

Prosthetic management of an ocular defect

Directory of Open Access Journals (Sweden)

Siddesh Kumar Chintal

2010-01-01

Full Text Available The disfigurement associated with the loss of an eye can cause significant physical and emotional problems. Various treatment modalities are available, one of which is implants. Although implant has a superior outcome, it may not be advisable in all patients due to economic factors. The present article describes the prosthetic management of an ocular defect with a custom-made ocular prosthesis.

Implantes de hidroxiapatita em falhas ósseas produzidas no fêmur de ratos submetidos ao tabagismo passivo Hydroxyapatite implants in bone defects produced in rat femurs submitted to passive tobacco exposure

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Thiago Cerizza Pinheiro

2008-10-01

menores quando comparados com os do grupo controle. CONCLUSÃO: A neoformação óssea em defeitos do esqueleto pode ocorrer naturalmente em animais submetidos ao tabagismo passivo, no entanto, de forma mais lenta e em menor proporção.INTRODUCTION: Defects with bone mass loss are frequently treated with bone autografts. Endografts of bones using biomaterials, such as hydroxyapatite (HA also have been used for the same purpose, replacing autografts. However, bone tissue health conditions are basic for osteointegration of the implant. Thus, excessive tobacco consumption, either as an active or as a passive smoker, may harm the process of bone neoformation with a hydroxyapatite implant due to its deleterious effects to bone tissue. OBJECTIVE: To evaluate the nutritional status of the animals and the process of bone neoformation when porous hydroxyapatite granules are implanted in bone defects of the femur of rats submitted to passive tobacco exposure. METHOD: Porous hydroxyapatite granules were implanted in bone defects produced in the left distal femoral epiphysis of rats subjected to prolonged passive tobacco exposure. The animals were followed along the treatment of tobacco exposure during six months, to evaluate their physical conditions. After eight weeks of the bone implant with the biomaterial, the animals were sacrificed and the specimens of the implant region were submitted to routine histological testing, and maintained in paraffin blocks for morphometric histological and radiological analysis. RESULTS: The mass variation of the experimental group was found to be more intense than that of the control group. As to radiological findings, the control group had an apparent more radio lucent and organized image. In the morphological analysis, there was a better closing of the bone defect and osteointegration of hydroxyapatite in the control group. Upon comparing the volume of bone formed in the receiving area of the femur between the control and the experimental group

Nanosized Hydroxyapatite Coating on PEEK Implants Enhances Early Bone Formation: A Histological and Three-Dimensional Investigation in Rabbit Bone

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Pär Johansson

2015-06-01

Full Text Available Polyether ether ketone (PEEK has been frequently used in spinal surgery with good clinical results. The material has a low elastic modulus and is radiolucent. However, in oral implantology PEEK has displayed inferior ability to osseointegrate compared to titanium materials. One idea to reinforce PEEK would be to coat it with hydroxyapatite (HA, a ceramic material of good biocompatibility. In the present study we analyzed HA-coated PEEK tibial implants via histology and radiography when following up at 3 and 12 weeks. Of the 48 implants, 24 were HA-coated PEEK screws (test and another 24 implants served as uncoated PEEK controls. HA-coated PEEK implants were always osseointegrated. The total bone area (BA was higher for test compared to control implants at 3 (p < 0.05 and 12 weeks (p < 0.05. Mean bone implant contact (BIC percentage was significantly higher (p = 0.024 for the test compared to control implants at 3 weeks and higher without statistical significance at 12 weeks. The effect of HA-coating was concluded to be significant with respect to early bone formation, and HA-coated PEEK implants may represent a good material to serve as bone anchored clinical devices.

Implantation of refractive multifocal intraocular lens with a surface-embedded near section for cataract eyes complicated with a coexisting ocular pathology.

Science.gov (United States)

Ouchi, M; Kinoshita, S

2015-05-01

To evaluate the postoperative outcomes of cataract eyes complicated with coexisting ocular pathologies that underwent implantation of a refractive multifocal intraocular lens (MIOL) with a surface-embedded near section. LENTIS MPlus (Oculentis GmbH) refractive MIOLs were implanted in 15 eyes with ocular pathologies other than cataract (ie, six high-myopia eyes with an axial length longer than 28 mm, two fundus albipunctatus eyes, two branch retinal-vein occlusion eyes, four glaucoma eyes (one with high myopia), and two keratoconus eyes). Uncorrected or corrected distance and near visual acuity (VA) (UDVA, UNVA, CDVA, and CNVA), contrast sensitivity, and defocus curve were measured at 1 day and 6 months postoperatively, and each patient completed a 6-month postoperative questionnaire regarding vision quality and eyeglass use. Thirteen eyes (87%) registered 0 or better in CDVA and 12 eyes (73%) registered better than 0 in CNVA. Contrast sensitivity in the eyes of all patients was comparable to that of normal healthy subjects. No patient required eyeglasses for distance vision, but three patients (20%) required them for near vision. No patient reported poor or very poor vision quality. With careful case selection, sectorial refractive MIOL implantation is effective for treating cataract eyes complicated with ocular pathologies.

Histomorphometric Assessment of Implant Coating with A Mixture of Strontium Chloride and Hydroxyapatite at Different Concentration

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Jani Ghasak H

2018-01-01

Full Text Available Background/purpose: Surface properties are one of the major keys of successful implant osseointegration in addition to mechanical strength and excellent biocompatibility of implant material. The purpose of this study is to make histological and histomorphometric analysis of an implant coated with strontium chloride (SrCl2 mixed with hydroxyapatite (HA at different concentrations, in rabbit tibia at 2 and 6 weeks of implantation time. Method: 48 commercially pure titanium screw shaped implants were placed in 24 healthy adult New Zeeland rabbits, each rabbit received 2 implants; one coated with mixture 1 (25% HA and 75% SrCl2 and the other coated with mixture 2 (75% HA and 25% SrCl2. Twelve rabbits were sacrificed at 2 weeks of healing and other twelve after 6 weeks. The new bone area and number of cells (osteoblast and osteoclast were assessed by light microscope. Result: Statistical analysis showed significant differences in new bone formation ratio after 2 weeks of healing and non-significant differences after 6 weeks of healing. Data also suggested that osteoblast was increased, and osteoclast was decreased in mixture 2 (75% HA and 25% SrCl2 more than mixture 1 (25% HA and 75% SrCl2. Conclusion: There was a significantly higher new bone formation ratio of mix 2 (25%Sr-75%HA coated Cp-Ti implants than mix 1 (75% Sr- 25% HA coated Cp-Ti implant at 2 weeks healing period, also there was an increase in new bone formation ratio with time for both coated materials (SrCl2 implants.

In vitro characterization of hydroxyapatite layers deposited by APS and HVOF thermal spraying methods

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Radu Alexandru Roşu

2012-03-01

Full Text Available Titanium alloys are successfully used in medicine as implants due to their high mechanical properties and good biocompatibility. To improve implant osseointegration of titanium alloys, they are covered with hydroxyapatite because of its bioactive properties. Coating the implants with hydroxyapatite by thermal spraying, due to the temperatures developed during the deposition process, the structure can be degraded, leading to formation of secondary phases, such as TCP, TT CP, CaO. The paper presents the experimental results of hydroxyapatite layers deposition by two thermal spraying methods: Atmospheric Plasma Spraying (APS and High Velocity Oxy-Fuel (HVOF. The microstructure of the deposited layers is characterized by X-ray diffraction analysis and electronic microscopy. The bioactivity of the hydroxyapatite layers was investigated in Simulated Body Fluid (SBF by immersing the covered samples deposited by the two thermal spraying methods. In both cases the coatings did not present defects as cracks or microcracks. X-ray diffraction performed on hydroxyapatite deposited layers shows that the structure was strongly influenced by plasma jet temperature, the structure consisting mainly of TCP (Ca3PO42. The samples deposited by HVO F after immersing in SBF lead to formation of biological hydroxyapatite, certifying the good bioactivity of the coatings.

Hydroxyapatite-coated magnesium implants with improved in vitro and in vivo biocorrosion, biocompatibility, and bone response.

Science.gov (United States)

Kim, Sae-Mi; Jo, Ji-Hoon; Lee, Sung-Mi; Kang, Min-Ho; Kim, Hyoun-Ee; Estrin, Yuri; Lee, Jong-Ho; Lee, Jung-Woo; Koh, Young-Hag

2014-02-01

Magnesium and its alloys are candidate materials for biodegradable implants; however, excessively rapid corrosion behavior restricts their practical uses in biological systems. For such applications, surface modification is essential, and the use of anticorrosion coatings is considered as a promising avenue. In this study, we coated Mg with hydroxyapatite (HA) in an aqueous solution containing calcium and phosphate sources to improve its in vitro and in vivo biocorrosion resistance, biocompatibility and bone response. A layer of needle-shaped HA crystals was created uniformly on the Mg substrate even when the Mg sample had a complex shape of a screw. In addition, a dense HA-stratum between this layer and the Mg substrate was formed. This HA-coating layer remarkably reduced the corrosion rate of the Mg tested in a simulated body fluid. Moreover, the biological response, including cell attachment, proliferation and differentiation, of the HA-coated samples was enhanced considerably compared to samples without a coating layer. The preliminary in vivo experiments also showed that the biocorrosion of the Mg implant was significantly retarded by HA coating, which resulted in good mechanical stability. In addition, in the case of the HA-coated implants, biodegradation was mitigated, particularly over the first 6 weeks of implantation. This considerably promoted bone growth at the interface between the implant and bone. These results confirmed that HA-coated Mg is a promising material for biomedical implant applications. © 2013 Wiley Periodicals, Inc.

In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants

Energy Technology Data Exchange (ETDEWEB)

Sutha, S.; Kavitha, K.; Karunakaran, G.; Rajendran, V., E-mail: veerajendran@gmail.com

2013-10-15

A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58–1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Highlights: • Hydroxyapatite particles are prepared with various silicon concentration • Prepared composites are blended with chitosan and coated on the implant • Corrosion resistance in simulated body fluid improves its stability • Increase in silicon concentration improves the antibacterial activity • Coated plate exhibit high in-vitro bioactivity in simulated body fluid.

In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants

International Nuclear Information System (INIS)

Sutha, S.; Kavitha, K.; Karunakaran, G.; Rajendran, V.

2013-01-01

A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58–1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Highlights: • Hydroxyapatite particles are prepared with various silicon concentration • Prepared composites are blended with chitosan and coated on the implant • Corrosion resistance in simulated body fluid improves its stability • Increase in silicon concentration improves the antibacterial activity • Coated plate exhibit high in-vitro bioactivity in simulated body fluid

Comparison of new bone formation, implant integration, and biocompatibility between RGD-hydroxyapatite and pure hydroxyapatite coating for cementless joint prostheses--an experimental study in rabbits.

Science.gov (United States)

Bitschnau, Achim; Alt, Volker; Böhner, Felicitas; Heerich, Katharina Elisabeth; Margesin, Erika; Hartmann, Sonja; Sewing, Andreas; Meyer, Christof; Wenisch, Sabine; Schnettler, Reinhard

2009-01-01

This is the first work to report on additional Arginin-Glycin-Aspartat (RGD) coating on precoated hydroxyapatite (HA) surfaces regarding new bone formation, implant bone contact, and biocompatibility compared to pure HA coating and uncoated stainless K-wires. There were 39 rabbits in total with 6 animals for the RGD-HA and HA group for the 4 week time period and 9 animals for each of the 3 implant groups for the 12 week observation. A 2.0 K-wire either with RGD-HA or with pure HA coating or uncoated was placed into the intramedullary canal of the tibia. After 4 and 12 weeks, the tibiae were harvested and three different areas of the tibia were assessed for quantitative and qualitative histology for new bone formation, direct implant bone contact, and formation of multinucleated giant cells. Both RGD-HA and pure HA coating showed statistically higher new bone formation and implant bone contact after 12 weeks than the uncoated K-wire. There were no significant differences between the RGD-HA and the pure HA coating in new bone formation and direct implant bone contact after 4 and 12 weeks. The number of multinucleated giant did not differ significantly between the RGD-HA and HA group after both time points. Overall, no significant effects of an additional RGD coating on HA surfaces were detected in this model after 12 weeks. (c) 2008 Wiley Periodicals, Inc.

Production and analysis of hydroxyapatite from Australian corals via hydrothermal process

International Nuclear Information System (INIS)

Hu, J.; Russell, J.; Ben-Nissan, B.

1999-01-01

Since the 1970s it is well known that if a biocompatible ceramic prosthesis with appropriate interconnected pores is used, growth of hard and soft tissue into the surface pores will be observed. A very strong attachment and hence the resultant mechanical and chemical bond to the existing surrounding tissue will be produced. Current artificial eyes although widely used encounter various problems due to the their motility and fail to deliver natural movement. They also cause sagging of the lids due to unsupported weight of the prosthesis. It is expected that application of a porous bioceramic such as the hydroxyapatite can generate good bonding to the tissue and hence a life-like eye movement. Hydroxyapatite (HAp) and related calcium phosphates have been studied for many years as implant materials, due to their similarity with the mineral phase of bone. From the point of view of biocompatibility, HAp seems to be the most suitable ceramic material for tissue replacement implants. Hydroxyapatite ceramics do not exhibit any cytoxic effects. It shows excellent biocompatibility with hard and soft tissues. Moreover, HAp can directly bond to the bone. Various preparation methods for HAp including the hydrothermal method have been used. The hydrothermal method was first used for hydroxyapatite formation directly from corals in 1974 by Roy and Linnehan. Complete replacement of aragonite by phosphatic material was achieved under 270degC and 103MPa using the hydrothermal process. This process has the disadvantage that the hydrothermal treatment must be carried out at a relatively high temperature under very high pressure. In 1996, HAp derived from Indian coral using hydrothermal process was developed by Sivakumar et al. However, the resultant material was in the form of a powder. Australia has rich variety of corals. Their application for implants have been studied very little. In this study, Australian corals selected were used for hydroxyapatite conversion. A new hydrothermal

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

Directory of Open Access Journals (Sweden)

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.

One-stage explant-implant procedure of exposed porous orbital implants

DEFF Research Database (Denmark)

Toft, Peter B; Rasmussen, Marie L Roed; Prause, Jan Ulrik

2011-01-01

Purpose:  To investigate the risks of implant exposure after a combined explant-implant procedure in patients with an exposed porous orbital implant. Methods:  Twenty-four consecutive patients who had a combined explant-implant procedure of an exposed hydroxyapatite (21) or porous polyethylene (3...... at the same procedure in sockets without profound signs of infection. The procedure carries a possible risk of poor motility....

Fabrication and characterization of porous hydroxyapatite ocular ...

Indian Academy of Sciences (India)

Unknown

risk of life or risk to the other eye of the patient. The lost eye can be ... fibrovascular growth are termed as integrated implants. Porous implants have the .... They were maintained under identical environment, management and standard diet with ...

[Enforcing osseointegration of dental implantates spray-coated by bioceramics with the help of hyaluronic acid and hydroxyapatite gel in experimental conditions].

Science.gov (United States)

Kulakov, A A; Volozhin, A I; Tkachenko, V M; Doktorov, A A; Salim, Ibrakhim Samir

2007-01-01

Influence of HAP-gel (2 g of 2% solution of hyaluronic acid mixed with 0,5 g of hydroxyapatite and 0,1 ml of colloidal silver) upon osseointegration in case of delayed introduction of titanium implantates in dog jaw. By scanning electron microscopy it was shown that solely use either of HAP-gel or of ceramic spraying increased direct contact area between bone and implantates in the 6 and 9 months time period. Combination of spray-coated ceramic with HAP-gel was effective in 3 months after implantation, when solely the HAP-gel or the ceramic spraying were little effective. In the following terms of experiment (6 and 9 months) significant differences between groups 3 and 4 (implantate with ceramic spraying but without HAP-gel in the alveolus and implantate with ceramic spraying and with HAP-gel in the alveolus) were not found. The area of implantate integration with jaw bone (cortical part of it was excluded) was equal to 80% and was maximal for the given conditions of the experiment.

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

Science.gov (United States)

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.

In vitro and in vivo evaluation of silicated hydroxyapatite and impact of insulin adsorption.

Science.gov (United States)

Lasgorceix, M; Costa, A M; Mavropoulos, E; Sader, M; Calasans, M; Tanaka, M N; Rossi, A; Damia, C; Chotard-Ghodsnia, R; Champion, E

2014-10-01

This study evaluates the biological behaviour, in vitro and in vivo, of silicated hydroxyapatite with and without insulin adsorbed on the material surface. Insulin was successfully adsorbed on hydroxyapatite and silicated hydroxyapatite bioceramics. The modification of the protein secondary structure after the adsorption was investigated by means of infrared and circular dichroism spectroscopic methods. Both results were in agreement and indicated that the adsorption process was likely to change the secondary structure of the insulin from a majority of α-helix to a β-sheet form. The biocompatibility of both materials, with and without adsorbed insulin on their surface, was demonstrated in vitro by indirect and direct assays. A good viability of the cells was found and no proliferation effect was observed regardless of the material composition and of the presence or absence of insulin. Dense granules of each material were implanted subcutaneously in mice for 1, 3 and 9 weeks. At 9 weeks of implantation, a higher inflammatory response was observed for silicated hydroxyapatite than for pure hydroxyapatite but no significant effect of adsorbed insulin was detected. Though the presence of silicon in hydroxyapatite did not improve the biological behaviour, the silicon substituted hydroxyapatite remained highly viable.

Enhanced osteoconductivity of sodium-substituted hydroxyapatite by system instability.

Science.gov (United States)

Sang Cho, Jung; Um, Seung-Hoon; Su Yoo, Dong; Chung, Yong-Chae; Hye Chung, Shin; Lee, Jeong-Cheol; Rhee, Sang-Hoon

2014-07-01

The effect of substituting sodium for calcium on enhanced osteoconductivity of hydroxyapatite was newly investigated. Sodium-substituted hydroxyapatite was synthesized by reacting calcium hydroxide and phosphoric acid with sodium nitrate followed by sintering. As a control, pure hydroxyapatite was prepared under identical conditions, but without the addition of sodium nitrate. Substitution of calcium with sodium in hydroxyapatite produced the structural vacancies for carbonate ion from phosphate site and hydrogen ion from hydroxide site of hydroxyapatite after sintering. The total system energy of sodium-substituted hydroxyapatite with structural defects calculated by ab initio methods based on quantum mechanics was much higher than that of hydroxyapatite, suggesting that the sodium-substituted hydroxyapatite was energetically less stable compared with hydroxyapatite. Indeed, sodium-substituted hydroxyapatite exhibited higher dissolution behavior of constituent elements of hydroxyapatite in simulated body fluid (SBF) and Tris-buffered deionized water compared with hydroxyapatite, which directly affected low-crystalline hydroxyl-carbonate apatite forming capacity by increasing the degree of apatite supersaturation in SBF. Actually, sodium-substituted hydroxyapatite exhibited markedly improved low-crystalline hydroxyl-carbonate apatite forming capacity in SBF and noticeably higher osteoconductivity 4 weeks after implantation in calvarial defects of New Zealand white rabbits compared with hydroxyapatite. In addition, there were no statistically significant differences between hydroxyapatite and sodium-substituted hydroxyapatite on cytotoxicity as determined by BCA assay. Taken together, these results indicate that sodium-substituted hydroxyapatite with structural defects has promising potential for use as a bone grafting material due to its enhanced osteoconductivity compared with hydroxyapatite. © 2013 Wiley Periodicals, Inc.

Gallium-containing hydroxyapatite for potential use in orthopedics

International Nuclear Information System (INIS)

Melnikov, P.; Teixeira, A.R.; Malzac, A.; Coelho, M. de B.

2009-01-01

A novel material that may be recommended for grafts and implants stimulating bone growth has been obtained by introducing gallium ions (up to 11.0 mass%) into crystalline lattice of hydroxyapatite. The doping was carried out using gallium nitrate and sodium gallate solutions. In both cases, lattice parameters of gallium-doped hydroxyapatite are identical to those of pure synthetic hydroxyapatite. Gallium does not replace calcium as a result of heterovalent substitution and consequently produces no distortions in the framework of hydroxyapatite matrix. It remains strongly fixed in the form of solid solution of intercalation. According to scanning electron microscopy images gallium insertion does not cause any morphological alterations in hydroxyapatite structure and the product developed meets physico-chemical criteria for biomaterial to be employed in orthopedic practice and local handling of traumatic injuries. Its future usage opens the opportunity to enhance osteosynthesis and calcium retention in loco.

Bioactive polyurethane implants with hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

Rozhnova, R.; Kebuladze, I.; Galatenko, N. [NAS Ukraine, Kiev (Ukraine). Dept. of Polymers of Medical Appointment

2001-07-01

Biologically active polyurethane compositions for plastic of bone defects that contain bioceramic - hydroxyapatite (HAP) and immunomodulator - levamisole (LEV) were designed. The influence of the biologically active fillers in structure polyurethane compositions on their physical and chemical properties in condition in vivo by method of Equilibrium Swelling, method of IR-spectroscopy, roentgen-structural analysis was studied. The introduce in structure of the biodegraded polymeric matrix of HAP is established to promote accumulation of the inorganic component of bone tissue in vivo which is being by basis of the bone formation in regenerating tissue. (orig.)

Application of interconnected porous hydroxyapatite ceramic block for onlay block bone grafting in implant treatment: A case report.

Science.gov (United States)

Ohta, Kouji; Tada, Misato; Ninomiya, Yoshiaki; Kato, Hiroki; Ishida, Fumi; Abekura, Hitoshi; Tsuga, Kazuhiro; Takechi, Masaaki

2017-12-01

Autogenous block bone grafting as treatment for alveolar ridge atrophy has various disadvantages, including a limited availability of sufficiently sized and shaped grafts, donor site morbidity and resorption of the grafted bone. As a result, interconnected porous hydroxyapatite ceramic (IP-CHA) materials with high porosity have been developed and used successfully in orthopedic cases. To the best of the author's knowledge, this is the first report of clinical application of an IP-CHA block for onlay grafting for implant treatment in a patient with horizontal alveolar atrophy. The present study performed onlay block grafting using an IP-CHA block to restore bone volume for implant placement in the alveolar ridge area without collecting autogenous bone. Dental X-ray findings revealed that the border of the IP-CHA block became increasingly vague over the 3-year period, whereas CT scanning revealed that the gap between the block and bone had a smooth transition, indicating that IP-CHA improved the process of integration with host bone. In follow-up examinations over a period of 5 years, the implants and superstructures had no problems. An IP-CHA block may be useful as a substitute for onlay block bone grafting in implant treatment.

Mechanical properties and biocompatibility of the sputtered Ti doped hydroxyapatite.

Science.gov (United States)

Vladescu, A; Padmanabhan, S C; Ak Azem, F; Braic, M; Titorencu, I; Birlik, I; Morris, M A; Braic, V

2016-10-01

The hydroxyapatite enriched with Ti were prepared as possible candidates for biomedical applications especially for implantable devices that are in direct contact to the bone. The hydroxyapatites with different Ti content were prepared by RF magnetron sputtering on Ti-6Al-4V alloy using pure hydroxyapatite and TiO2 targets. The content of Ti was modified by changing the RF power fed on TiO2 target. The XPS and FTIR analyses revealed the presence of hydroxyapatite structure. The hardness and elastic modulus of the hydroxyapatite were increased by Ti addition. After 5 days of culture, the cell viability of the Ti-6Al-4V was enhanced by depositing with undoped or doped hydroxyapatite. The Ti additions led to an increase in cell viability of hydroxyapatite, after 5 days of culture. The electron microscopy showed the presence of more cells on the surface of Ti-enriched hydroxyapatite than those observed on the surface of the uncoated alloys or undoped hydroxyapatite. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite: a histomorphometric study in rabbit bone.

Science.gov (United States)

Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito; Kjellin, Per; Currie, Fredrik; Wennerberg, Ann

2016-01-01

Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants in the rabbit femur were histologically evaluated at 3 weeks and 12 weeks after surgery. Twelve of the 24 implants were HA coated (test), and the remaining 12 served as uncoated PEEK controls. At 3 weeks and 12 weeks, the mean bone-implant contact was higher for test compared to control (P<0.05). The bone area inside the threads was comparable in the two groups, but the perforating hole showed more bone area for the HA-coated implants at both healing points (P<0.01). With these results, we conclude that nano-sized HA coating on PEEK implants significantly improved the osteogenic properties, and in a clinical situation this material composition may serve as an implant where a rapid bone fusion is essential.

Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

International Nuclear Information System (INIS)

Duta, L.; Oktar, F.N.; Stan, G.E.; Popescu-Pelin, G.; Serban, N.; Luculescu, C.; Mihailescu, I.N.

2013-01-01

Highlights: ► HA coatings synthesized by pulsed laser deposition. ► Comparative study of commercial vs. animal origin materials. ► HA coatings of animal origin were rougher and more adherent to substrates. ► Animal origin films can be considered as promising candidates for implant coatings. - Abstract: We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of ∼2 μm. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical–chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

The vestibular implant: Frequency-dependency of the electrically evoked Vestibulo-Ocular Reflex in humans

Directory of Open Access Journals (Sweden)

Raymond eVan De Berg

2015-01-01

Full Text Available The Vestibulo-Ocular Reflex (VOR shows frequency-dependent behavior. This study investigated whether the characteristics of the electrically evoked VOR (eVOR elicited by a vestibular implant, showed the same frequency-dependency.Twelve vestibular electrodes implanted in 7 patients with bilateral vestibular hypofunction were tested. Stimuli consisted of amplitude-modulated electrical stimulation with a sinusoidal profile at frequencies of 0.5Hz, 1Hz, and 2Hz. The main characteristics of the eVOR were evaluated and compared to the natural VOR characteristics measured in a group of age-matched healthy volunteers who were subjected to horizontal whole body rotations with equivalent sinusoidal velocity profiles at the same frequencies.A strong and significant effect of frequency was observed in the total peak eye velocity of the eVOR. This effect was similar to that observed in the natural VOR. Other characteristics of the (eVOR (angle, habituation-index, and asymmetry showed no significant frequency-dependent effect. In conclusion, this study demonstrates that, at least at the specific (limited frequency range tested, responses elicited by a vestibular implant closely mimic the frequency-dependency of the normal vestibular system.

Comparative Evaluation of Osseointegration of Dental Endodontic Implants with and without Plasma- Sprayed Hydroxy apatite Coating

Directory of Open Access Journals (Sweden)

Moosavi SB

2001-05-01

Full Text Available Bone osseointegration around dental implant can cause earlier stabilization and fixation of implant and reduce healing time. Hydroxyapatite coating can affect bone osseointegration and enhance its rates. The aim of this study was comparison of osseointegration between plasma sprayed hydroxyapatite coated and uncoated dental implants in cats. Four endodontic implants including, vitallium and two stainless steel with and without hydroxyapatite coating were prepared and placed in mandibular canines of 20 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, investigation by scanning electron microscopy showed significant difference in ossointegration between coated and uncoated dental implants and average bone osseointegration of coated implants was more than uncoated implants.

In vitro mechanical integrity of hydroxyapatite coated magnesium alloy

International Nuclear Information System (INIS)

Kannan, M Bobby; Orr, Lynnley

2011-01-01

The mechanical integrity of resorbable implants during service, especially in load bearing orthopaedic applications, is critical. The high degradation rate of resorbable magnesium and magnesium-based implants in body fluid may potentially cause premature in-service failure. In this study, a magnesium alloy (AZ91) was potentiostatically coated with hydroxyapatite at different cathodic voltages in an attempt to enhance the mechanical integrity. The mechanical integrity of the uncoated and hydroxyapatite coated alloys was evaluated after in vitro testing of the coated samples in simulated body fluid (SBF). The uncoated alloy showed 40% loss in the mechanical strength after five days exposure to SBF. However, the hydroxyapatite coated alloy exposed to SBF showed 20% improvement in the mechanical strength as compared to that of the uncoated alloy. The alloy coated potentiostatically at -2 V performed better than the -3 V coated alloy. The cross-sectional analysis of the coatings revealed relatively uniform coating thickness for the -2 V coated alloy, whereas the -3 V coated alloy exhibited areas of uneven coating. This can be attributed to the increase in hydrogen evolution on the alloy during -3 V coating as compared to -2 V coating. The scanning electron micrographs of the in vitro tested alloy revealed that hydroxyapatite coating significantly reduced the localized corrosion of the alloy, which is critical for better in-service mechanical integrity. Thus, the study suggests that the in vitro mechanical integrity of resorbable magnesium-based alloy can be improved by potentiostatic hydroxyapatite coating.

In vitro mechanical integrity of hydroxyapatite coated magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Kannan, M Bobby; Orr, Lynnley, E-mail: bobby.mathan@jcu.edu.au [Discipline of Chemical Engineering, School of Engineering and Physical Sciences, James Cook University, Townsville, Queensland 4811 (Australia)

2011-08-15

The mechanical integrity of resorbable implants during service, especially in load bearing orthopaedic applications, is critical. The high degradation rate of resorbable magnesium and magnesium-based implants in body fluid may potentially cause premature in-service failure. In this study, a magnesium alloy (AZ91) was potentiostatically coated with hydroxyapatite at different cathodic voltages in an attempt to enhance the mechanical integrity. The mechanical integrity of the uncoated and hydroxyapatite coated alloys was evaluated after in vitro testing of the coated samples in simulated body fluid (SBF). The uncoated alloy showed 40% loss in the mechanical strength after five days exposure to SBF. However, the hydroxyapatite coated alloy exposed to SBF showed 20% improvement in the mechanical strength as compared to that of the uncoated alloy. The alloy coated potentiostatically at -2 V performed better than the -3 V coated alloy. The cross-sectional analysis of the coatings revealed relatively uniform coating thickness for the -2 V coated alloy, whereas the -3 V coated alloy exhibited areas of uneven coating. This can be attributed to the increase in hydrogen evolution on the alloy during -3 V coating as compared to -2 V coating. The scanning electron micrographs of the in vitro tested alloy revealed that hydroxyapatite coating significantly reduced the localized corrosion of the alloy, which is critical for better in-service mechanical integrity. Thus, the study suggests that the in vitro mechanical integrity of resorbable magnesium-based alloy can be improved by potentiostatic hydroxyapatite coating.

Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

Science.gov (United States)

Linsheng, Li; Guoxiang, Lin; Lihui, Li

2016-08-12

In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.

Interactions of hydroxyapatite surfaces: conditioning films of human whole saliva.

Science.gov (United States)

Cárdenas, Marité; Valle-Delgado, Juan José; Hamit, Jildiz; Rutland, Mark W; Arnebrant, Thomas

2008-07-15

Hydroxyapatite is a very interesting material given that it is the main component in tooth enamel and because of its uses in bone implant applications. Therefore, not only the characterization of its surface is of high relevance but also designing reliable methods to study the interfacial properties of films adsorbed onto it. In this paper we apply the colloidal probe atomic force microscopy method to investigate the surface properties of commercially available hydroxyapatite surfaces (both microscopic particles and macroscopic discs) in terms of interfacial and frictional forces. In this way, we find that hydroxyapatite surfaces at physiological relevant conditions are slightly negatively charged. The surfaces were then exposed to human whole saliva, and the surface properties were re-evaluated. A thick film was formed that was very resistant to mechanical stress. The frictional measurements demonstrated that the film was indeed highly lubricating, supporting the argument that this system may prove to be a relevant model for evaluating dental and implant systems.

Microporous Ti implant compact coated with hydroxyapatite produced by electro-discharge-sintering and electrostatic-spray-deposition.

Science.gov (United States)

Jo, Y J; Kim, Y H; Jo, Y H; Seong, J G; Chang, S Y; Van Tyne, C J; Lee, W H

2014-11-01

A single pulse of 1.5 kJ/0.7 g of atomized spherical Ti powder from 300 μF capacitor was applied to produce the porous-surfaced Ti implant compact by electro-discharge-sintering (EDS). A solid core surrounded by porous layer was self-consolidated by a discharge in the middle of the compact in 122 μsec. Average pore size, porosity, and compressive yield strength of EDS Ti compact were estimated to be about 68.2 μm, 25.5%, and 266.4 MPa, respectively. Coatings with hydroxyapatite (HAp) on the Ti compact were conducted by electrostatic-spray-deposition (ESD) method. As-deposited HAp coating was in the form of porous structure and consisted of HAp particles which were uniformly distributed on the Ti porous structure. By heat-treatment at 700 degrees C, HAp particles were agglomerated each other and melted to form a highly smooth and homogeneous HAp thin film consisted of equiaxed nano-scaled grains. Porous-surfaced Ti implant compacts coated with highly crystalline apatite phase were successfully obtained by using the EDS and ESD techniques.

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.

Characterisation of Suspension Precipitated Nanocrystalline Hydroxyapatite Powders

International Nuclear Information System (INIS)

Mallik, P K; Swain, P.K.; Patnaik, S.C

2016-01-01

Hydroxyapatite (HA) is a well-known biomaterial for coating on femoral implants, filling of dental cavity and scaffold for tissue replacement. Hydroxyapatite possess limited load bearing capacity due to their brittleness. In this paper, the synthesis of nanocrystalline hydroxyapatite powders was prepared by dissolving calcium oxide in phosphoric acid, followed by addition of ammonia liquor in a beaker. The prepared solution was stirred by using magnetic stirrer operated at temperature of 80°C for an hour. This leads to the formation of hydroxyapatite precipitate. The precipitate was dried in oven for overnight at 100°C. The dried agglomerated precipitate was calcined at 800°C in conventional furnace for an hour. The influence of calcium oxide concentration and pH on the resulting precipitates was studied using BET, XRD and SEM. As result, a well-defined sub-rounded morphology of powders size of ∼41 nm was obtained with a salt concentration of 0.02 M. Finally, it can be concluded that small changes in the reaction conditions led to large changes in final size, shape and degree of aggregation of the hydroxyapatite particles. (paper)

In vitro mechanical integrity of hydroxyapatite coated magnesium alloy.

Science.gov (United States)

Kannan, M Bobby; Orr, Lynnley

2011-08-01

The mechanical integrity of resorbable implants during service, especially in load bearing orthopaedic applications, is critical. The high degradation rate of resorbable magnesium and magnesium-based implants in body fluid may potentially cause premature in-service failure. In this study, a magnesium alloy (AZ91) was potentiostatically coated with hydroxyapatite at different cathodic voltages in an attempt to enhance the mechanical integrity. The mechanical integrity of the uncoated and hydroxyapatite coated alloys was evaluated after in vitro testing of the coated samples in simulated body fluid (SBF). The uncoated alloy showed 40% loss in the mechanical strength after five days exposure to SBF. However, the hydroxyapatite coated alloy exposed to SBF showed 20% improvement in the mechanical strength as compared to that of the uncoated alloy. The alloy coated potentiostatically at -2 V performed better than the -3 V coated alloy. The cross-sectional analysis of the coatings revealed relatively uniform coating thickness for the -2 V coated alloy, whereas the -3 V coated alloy exhibited areas of uneven coating. This can be attributed to the increase in hydrogen evolution on the alloy during -3 V coating as compared to -2 V coating. The scanning electron micrographs of the in vitro tested alloy revealed that hydroxyapatite coating significantly reduced the localized corrosion of the alloy, which is critical for better in-service mechanical integrity. Thus, the study suggests that the in vitro mechanical integrity of resorbable magnesium-based alloy can be improved by potentiostatic hydroxyapatite coating. © 2011 IOP Publishing Ltd

Biocompatible cephalosporin-hydroxyapatite-poly(lactic-co-glycolic acid)-coatings fabricated by MAPLE technique for the prevention of bone implant associated infections

Science.gov (United States)

Rădulescu, Dragoş; Grumezescu, Valentina; Andronescu, Ecaterina; Holban, Alina Maria; Grumezescu, Alexandru Mihai; Socol, Gabriel; Oprea, Alexandra Elena; Rădulescu, Marius; Surdu, Adrian; Trusca, Roxana; Rădulescu, Radu; Chifiriuc, Mariana Carmen; Stan, Miruna S.; Constanda, Sabrina; Dinischiotu, Anca

2016-06-01

In this study we aimed to obtain functionalized thin films based on hydroxyapatite/poly(lactic-co-glycolic acid) (HAp/PLGA) containing ceftriaxone/cefuroxime antibiotics (ATBs) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The prepared thin films were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-Ray diffraction (XRD), selected area electron diffraction (SAED), and infra red (IR) analysis. HAp/PLGA/ATBs thin films sustained the growth of human osteoblasts, proving their good biocompatibility. The microscopic evaluation and the culture-based quantitative assay of the E. coli biofilm development showed that the thin films inhibited the initial step of microbial attachment as well as the subsequent colonization and biofilm development on the respective surfaces. This study demonstrates that MAPLE technique could represent an appealing technique for the fabrication of antibiotics-containing polymeric implant coatings. The bioevaluation results recommend this type of surfaces for the prevention of bone implant microbial contamination and for the enhanced stimulation of the implant osseointegration process.

Characterization of hydroxyapatite coating by pulse laser deposition technique on stainless steel 316 L by varying laser energy

International Nuclear Information System (INIS)

Khandelwal, Himanshu; Singh, Gurbhinder; Agrawal, Khelendra; Prakash, Satya; Agarwal, R.D.

2013-01-01

Highlights: ► Hydroxyapatite coating was successfully deposited on stainless steel substrate by pulse laser deposition at different energy levels (i.e. 300 mJ and 500 mJ, respectively). ► Variation in laser energy affects the surface characteristic of hydroxyapatite coating (particle size, surface roughness, uniformity, Ca/P ratio). ► Laser energy between 300 mJ and 500 mJ is the optimal choice for obtaining ideal Ca/P ratio. - Abstract: Hydroxyapatite is an attractive biomaterial mainly used in bone and tooth implants because it closely resembles human tooth and bone mineral and has proven to be biologically compatible with these tissues. In spite of this advantage of hydroxyapatite it has also certain limitation like inferior mechanical properties which do not make it suitable for long term load bearing applications; hence a lot of research is going on in the development of hydroxyapatite coating over various metallic implants. These metallic implants have good biocompatibility and mechanical properties. The aim of the present work is to deposit hydroxyapatite coating over stainless steel grade 316 L by pulse laser deposition technique by varying laser energy. To know the effect of this variation, the coatings were than characterized in detail by X-ray diffraction, finite emission-scanning electron microscope, atomic force microscope and energy dispersive X-ray spectroscopy.

Decreased Staphylococcus aureus and increased osteoblast density on nanostructured electrophoretic-deposited hydroxyapatite on titanium without the use of pharmaceuticals.

Science.gov (United States)

Mathew, Dennis; Bhardwaj, Garima; Wang, Qi; Sun, Linlin; Ercan, Batur; Geetha, Manisavagam; Webster, Thomas J

2014-01-01

Plasma-spray deposition of hydroxyapatite on titanium (Ti) has proven to be a suboptimal solution to improve orthopedic-implant success rates, as demonstrated by the increasing number of orthopedic revision surgeries due to infection, implant loosening, and a myriad of other reasons. This could be in part due to the high heat involved during plasma-spray deposition, which significantly increases hydroxyapatite crystal growth into the nonbiologically inspired micron regime. There has been a push to create nanotopographies on implant surfaces to mimic the physiological nanostructure of native bone and, thus, improve osteoblast (bone-forming cell) functions and inhibit bacteria functions. Among the several techniques that have been adopted to develop nanocoatings, electrophoretic deposition (EPD) is an attractive, versatile, and effective material-processing technique. The in vitro study reported here aimed to determine for the first time bacteria responses to hydroxyapatite coated on Ti via EPD. There were six and three times more osteoblasts on the electrophoretic-deposited hydroxyapatite on Ti compared with Ti (control) and plasma-spray-deposited hydroxyapatite on Ti after 5 days of culture, respectively. Impressively, there were 2.9 and 31.7 times less Staphylococcus aureus on electrophoretic-deposited hydroxyapatite on Ti compared with Ti (control) and plasma-spray-deposited hydroxyapatite on Ti after 18 hours of culture, respectively. Compared with uncoated Ti and plasma-sprayed hydroxyapatite coated on Ti, the results provided significant promise for the use of EPD to improve bone-cell density and be used as an antibacterial coating without resorting to the use of antibiotics.

Improvement of the stability of hydroxyapatite through glass ceramic reinforcement.

Science.gov (United States)

Ha, Na Ra; Yang, Zheng Xun; Hwang, Kyu Hong; Kim, Tae Suk; Lee, Jong Kook

2010-05-01

Hydroxyapatite has achieved significant application in orthopedic and dental implants due to its excellent biocompatibility. Sintered hydroxyapatites showed significant dissolution, however, after their immersion in water or simulated body fluid (SBF). This grain boundary dissolution, even in pure hydroxyapatites, resulted in grain separation at the surfaces, and finally, in fracture. In this study, hydroxyapatite ceramics containing apatite-wollastonite (AW) or calcium silicate (SG) glass ceramics as additives were prepared to prevent the dissolution. AW and SG glass ceramics were added at 0-7 wt% and powder-compacted uniaxially followed by firing at moisture conditions. The glass phase was incorporated into the hydroxyapatite to act as a sintering aid, followed by crystallization, to improve the mechanical properties without reducing the biocompatibility. As seen in the results of the dissolution test, a significant amount of damage was reduced even after more than 14 days. TEM and SEM showed no decomposition of HA to the secondary phase, and the fracture toughness increased, becoming even higher than that of the commercial hydroxyapatite.

Synthesis of calcium hydrogen phosphate and hydroxyapatite coating on SS316 substrate through pulsed electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Rajib, E-mail: rajibju4@gmail.com [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Sengupta, Srijan [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Saha, Partha [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Das, Karabi; Das, Siddhartha [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

2016-12-01

The orthopaedic implants for human body are generally made of different biomaterials like stainless steels or Ti based alloys. However, it has been found that from surface properties point of view, none of these materials is attractive for fast tissue or cell growth on the surface of implant. This is one of the most important criteria to assure quick bonding between implant and body tissues vis-à-vis minimum recovery time for the patient. Keeping in view of the above facts, this work involves the pulsed electro-deposition coating of biocompatible hydroxyapatite and its group compounds from a diluted bath of calcium and phosphate salt at various current densities over the biomaterial sheet of SS316. SEM study confirms different morphologies of the coatings at different current densities. Characterization techniques like X-ray diffraction, SEM with EDX and FTIR have been used to confirm the phase and percentage quantity of hydroxyapatite compound in the depositions. This coating can serve as a medium for faster tissue growth over the metallic implants. - Highlights: • Composite coatings of CaHPO{sub 4} and hydroxyapatite for biomedical application through pulsed electro-deposition. • Achieved optimum phase composition in view of crystallinity of both the phases. • Overall coating crystallinity of around 70% in view better bio compatibility. • In cyclic voltammetry it is observed that the deposition reaction is completely irreversible. • The deposited coating consists of nano-crystalline hydroxyapatite similar to human bone; which exhibits better bio-compatibility.

Porous hydroxyapatite and biphasic calcium phosphate ceramics promote ectopic osteoblast differentiation from mesenchymal stem cells

Energy Technology Data Exchange (ETDEWEB)

Zhang Lingli; Fan Hongsong; Zhang Xingdong [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064 (China); Hanagata, Nobutaka; Ikoma, Toshiyuki [Biomaterials Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Maeda, Megumi; Minowa, Takashi, E-mail: HANAGATA.Nobutaka@nims.go.j [Nanotechnology Innovation Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan)

2009-04-15

Because calcium phosphate (Ca-P) ceramics have been used as bone substitutes, it is necessary to investigate what effects the ceramics have on osteoblast maturation. We prepared three types of Ca-P ceramics with different Ca-P ratios, i.e. hydroxyapatite (HA), beta-tricalcium phosphate ({beta}-TCP), and biphasic calcium phosphate (BCP) ceramics with dense-smooth and porous structures. Comprehensive gene expression microarray analysis of mouse osteoblast-like cells cultured on these ceramics revealed that porous Ca-P ceramics considerably affected the gene expression profiles, having a higher potential for osteoblast maturation. In the in vivo study that followed, porous Ca-P ceramics were implanted into rat skeletal muscle. Sixteen weeks after the implantation, more alkaline-phosphatase-positive cells were observed in the pores of hydroxyapatite and BCP, and the expression of the osteocalcin gene (an osteoblast-specific marker) in tissue grown in pores was also higher in hydroxyapatite and BCP than in {beta}-TCP. In the pores of any Ca-P ceramics, 16 weeks after the implantation, we detected the expressions of marker genes of the early differentiation stage of chondrocytes and the complete differentiation stage of adipocytes, which originate from mesenchymal stem cells, as well as osteoblasts. These marker gene expressions were not observed in the muscle tissue surrounding the implanted Ca-P ceramics. These observations indicate that porous hydroxyapatite and BCP had a greater potential for promoting the differentiation of mesenchymal stem cells into osteoblasts than {beta}-TCP.

Histomorphometric analysis of rat alveolar wound healing with hydroxyapatite alone or associated to BMPs

Directory of Open Access Journals (Sweden)

Brandão Alexandre C.

2002-01-01

Full Text Available Several materials and techniques have been proposed to improve alveolar wound healing and decrease loss of bone height and thickness that normally follow dental extraction. The objective of this research was the histologic analysis of bone morphogenetic proteins implanted into dental alveoli of rats after extraction. A total of 45 adult male Wistar rats were divided into three groups of 15 animals each: control (no treatment, implanted with pure hydroxyapatite (HA, 3 mg and implanted with hydroxyapatite plus bone morphogenetic proteins (HA/BMPs, 3 mg. Five animals from each group were sacrificed at 7, 21 and 42 days after extraction for the histometric analyses of the osteoconductive potential of hydroxyapatite associated or not with BMPs. After dissection, fixation, decalcification and serial microtomy of 6-mm thick sections, the samples were stained with hematoxylin-eosin for histologic and histometric analyses. Both HA and HA/BMPs caused a delay in wound healing compared to control animals, evaluated by the percentage of bone tissue in the alveoli. The treatment with HA/BMPs had the greatest delay at 21 days, even though it produced values similar to the control group at 42 days. The materials did not improve alveolar repair in the normal period of wound healing and the association of HA/BMPs did not have osteoconductive properties with granulated hydroxyapatite as the vehicle.

Cell shape and spreading of stromal (mesenchymal) stem cells cultured on fibronectin coated gold and hydroxyapatite surfaces

DEFF Research Database (Denmark)

Dolatshahi-Pirouz, A; Jensen, Thomas Hartvig Lindkjær; Kolind, Kristian

2011-01-01

In order to identify the cellular mechanisms leading to the biocompatibility of hydroxyapatite implants, we studied the interaction of human bone marrow derived stromal (mesenchymal) stem cells (hMSCs) with fibronectin-coated gold (Au) and hydroxyapatite (HA) surfaces. The adsorption of fibronectin...

Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite: a histomorphometric study in rabbit bone

Directory of Open Access Journals (Sweden)

Johansson P

2016-04-01

Full Text Available Pär Johansson,1 Ryo Jimbo,1 Yoshihito Naito,2 Per Kjellin,3 Fredrik Currie,3 Ann Wennerberg1 1Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden; 2Oral Implant Center, Tokushima University Hospital, Tokushima, Japan; 3Promimic AB, Stena Center, Göteborg, Sweden Abstract: Polyether ether ketone (PEEK possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants in the rabbit femur were histologically evaluated at 3 weeks and 12 weeks after surgery. Twelve of the 24 implants were HA coated (test, and the remaining 12 served as uncoated PEEK controls. At 3 weeks and 12 weeks, the mean bone–implant contact was higher for test compared to control (P<0.05. The bone area inside the threads was comparable in the two groups, but the perforating hole showed more bone area for the HA-coated implants at both healing points (P<0.01. With these results, we conclude that nano-sized HA coating on PEEK implants significantly improved the osteogenic properties, and in a clinical situation this material composition may serve as an implant where a rapid bone fusion is essential. Keywords: HA, PEEK, osseointegration, histology, orthopedics, in vivo

Kinetics of hydroxyapatite deposition on solid substrates modified by sequential implantation of Ca and P ions - Part I. FTIR and Raman spectroscopy study

Science.gov (United States)

Pecheva, Emilia V.; Pramatarova, Liliana D.; Maitz, Manfred F.; Pham, Mihn T.; Kondyuirin, Alexey V.

2004-07-01

In this work, the kinetics of hydroxyapatite (HA) deposition on solid substrates from liquid precursor (simulated body fluid, SBF) is investigated. The surfaces of stainless steel, silicon and silica glass substrates are modified by sequential implantation of Ca and P ions. Three groups of samples of each material: (i) ion-implanted; (ii) ion-implanted and thermally treated at 873 K in air for 60 min; and (iii) untreated are prepared. To investigate the kinetics of the HA deposition, all three groups of samples are introduced at equal conditions into SBF whose supersaturation is maintained during the whole 6-day period of immersion. The layers are analyzed by FTIR and Raman spectroscopy. Both techniques complement each other and show the formation of HA with incorporated CO 32- and HPO 42- groups. Following the kinetics of the deposition process, it is concluded that the speed of deposition is different on the three materials modified by Ca and P implantation and by oxidation, compared to untreated samples but in order to distinguish clearly the effect of the ion implantation and oxidation the very initial moment of nucleation and layer growth should be more carefully investigated.

XRD and SEM analysis of hydroxyapatite during immersion in stimulated physiological solutions

International Nuclear Information System (INIS)

Yusof Abdullah; Idris Besar; Rosmamuhamadani Ramli; Abd Razak Daud

2000-01-01

XRD and SEM techniques were used to analyse the apatite layer developed on the synthetic hydroxyapatite surface following immersion in the simulated body fluid (SBF) that mimics the conditions of material experiences after implantation in the human body. Initially, the new layers formed after 7 day's incubation and increased with immersion time as crystallization of apatite phase. The XRD confirmed that the deposited layer was hydroxyapatite and crystallographically. With time, the crystal growth become more random and the intensity of the peaks decreased. During immersion, hydroxyapatite was precipitated from the SBF and coherently scattered with very small crystal. The SEM observation shows that the new precipitates were increased as well as incubation period increased. Therefore, hydroxyapatite ceramics are suggested to have very good biocompatibility. (Author)

Surface analysis of titanium dental implants with different topographies

Directory of Open Access Journals (Sweden)

Silva M.H. Prado da

2000-01-01

Full Text Available Cylindrical dental implants made of commercially pure titanium were analysed in four different surface finishes: as-machined, Al2O3 blasted with Al2O3 particles, plasma-sprayed with titanium beads and electrolytically coated with hydroxyapatite. Scanning electron microscopy (SEM with Energy Dispersive X-ray Analysis (EDX revealed the topography of the surfaces and provided qualitative results of the chemical composition of the different implants. X-ray Photoelectron Spectroscopy (XPS was used to perform chemical analysis on the surface of the implants while Laser Scanning Confocal Microscopy (LSM produced topographic maps of the analysed surfaces. Optical Profilometry was used to quantitatively characterise the level of roughness of the surfaces. The implant that was plasma-sprayed and the hydroxyapatite coated implant showed the roughest surface, followed by the implant blasted with alumina and the as-machined implant. Some remnant contamination from the processes of blasting, coating and cleaning was detected by XPS.

Suspension thermal spraying of hydroxyapatite: microstructure and in vitro behaviour.

Science.gov (United States)

Bolelli, Giovanni; Bellucci, Devis; Cannillo, Valeria; Lusvarghi, Luca; Sola, Antonella; Stiegler, Nico; Müller, Philipp; Killinger, Andreas; Gadow, Rainer; Altomare, Lina; De Nardo, Luigi

2014-01-01

In cementless fixation of metallic prostheses, bony ingrowth onto the implant surface is often promoted by osteoconductive plasma-sprayed hydroxyapatite coatings. The present work explores the use of the innovative High Velocity Suspension Flame Spraying (HVSFS) process to coat Ti substrates with thin homogeneous hydroxyapatite coatings. The HVSFS hydroxyapatite coatings studied were dense, 27-37μm thick, with some transverse microcracks. Lamellae were sintered together and nearly unidentifiable, unlike conventional plasma-sprayed hydroxyapatite. Crystallinities of 10%-70% were obtained, depending on the deposition parameters and the use of a TiO2 bond coat. The average hardness of layers with low (hydroxyapatite, with a Weibull modulus of ≈3.3. During soaking in simulated body fluid, glassy coatings were progressively resorbed and replaced by a new, precipitated hydroxyapatite layer, whereas coatings with 70% crystallinity were stable up to 14days of immersion. The interpretation of the precipitation behaviour was also assisted by surface charge assessments, performed through Z-potential measurements. During in vitro tests, HA coatings showed no cytotoxicity towards the SAOS-2 osteoblast cell line, and surface cell proliferation was comparable with proliferation on reference polystyrene culture plates. © 2013.

Substituted Hydroxyapatites with Antibacterial Properties

Science.gov (United States)

Kolmas, Joanna; Groszyk, Ewa; Kwiatkowska-Różycka, Dagmara

2014-01-01

Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency. PMID:24949423

Substituted Hydroxyapatites with Antibacterial Properties

Directory of Open Access Journals (Sweden)

Joanna Kolmas

2014-01-01

Full Text Available Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

Can the Hydroxyapatite-Coated Skin-Penetrating Abutment for Bone Conduction Hearing Implants Integrate with the Surrounding Skin?

Science.gov (United States)

van Hoof, Marc; Wigren, Stina; Duimel, Hans; Savelkoul, Paul H M; Flynn, Mark; Stokroos, Robert Jan

2015-01-01

Percutaneous implants, such as bone conduction hearing implants, suffer from complications that include inflammation of the surrounding skin. A sealed skin-abutment interface can prevent the ingress of bacteria, which should reduce the occurrence of peri-abutment dermatitis. It was hypothesized that a hydroxyapatite (HA)-coated abutment in conjunction with soft tissue preservation surgery should enable integration with the adjacent skin. Previous research has confirmed that integration is never achieved with as-machined titanium abutments. Here, we investigate, in vivo, if skin integration is achievable in patients using a HA-coated abutment. One titanium abutment (control) and one HA-coated abutment (case) together with the surrounding skin were surgically retrieved from two patients who had a medical indication for this procedure. Histological sections of the skin were investigated using light microscopy. The abutment was qualitatively analyzed using scanning electron microscopy. The titanium abutment only had a partial and thin layer of attached amorphous biological material. The HA-coated abutment was almost fully covered by a pronounced thick layer of organized skin, composed of different interconnected structural layers. Proof-of-principle evidence that the HA-coated abutment can achieve integration with the surrounding skin was presented for the first time.

Optimal properties for coated titanium implants with the hydroxyapatite layer formed by the pulsed laser deposition technique

Science.gov (United States)

Himmlova, Lucia; Dostalova, Tatjana; Jelinek, Miroslav; Bartova, Jirina; Pesakova, V.; Adam, M.

1999-02-01

Pulsed laser deposition technique allow to 'tailor' bioceramic coat for metal implants by the change of deposition conditions. Each attribute is influenced by the several deposition parameters and each parameter change several various properties. Problem caused that many parameters has an opposite function and improvement of one property is followed by deterioration of other attribute. This study monitor influence of each single deposition parameter and evaluate its importance form the point of view of coat properties. For deposition KrF excimer laser in stainless-steel deposition chamber was used. Deposition conditions (ambient composition and pressures, metallic substrate temperature, energy density and target-substrate distance) were changed according to the film properties. A non-coated titanium implant was used as a control. Films with promising mechanical quality underwent an in vitro biological tests -- measurement of proliferation activity, observing cell interactions with macrophages, fibroblasts, testing toxicity of percolates, observing a solubility of hydroxyapatite (HA) coat. Deposition conditions corresponding with the optimal mechanical and biochemical properties are: metal temperature 490 degrees Celsius, ambient-mixture of argon and water vapor, energy density 3 Jcm-2, target-substrate distance 7.5 cm.

Effect of hydroxyapatite coating on risk of revision after primary total hip arthroplasty in younger patients: findings from the Danish Hip Arthroplasty Registry

DEFF Research Database (Denmark)

Paulsen, Aksel; Pedersen, Alma B; Johnsen, Søren P

2007-01-01

BACKGROUND: The effect of hydroxyapatite (HA) on implant survival in the medium and long term is uncertain. We studied the effect of HA coating of uncemented implants on the risk of cup and stem revision in primary total hip arthroplasty (THA). PATIENTS AND METHODS: Using the Danish Hip Arthropla......BACKGROUND: The effect of hydroxyapatite (HA) on implant survival in the medium and long term is uncertain. We studied the effect of HA coating of uncemented implants on the risk of cup and stem revision in primary total hip arthroplasty (THA). PATIENTS AND METHODS: Using the Danish Hip...

Biocompatible cephalosporin-hydroxyapatite-poly(lactic-co-glycolic acid)-coatings fabricated by MAPLE technique for the prevention of bone implant associated infections

Energy Technology Data Exchange (ETDEWEB)

Rădulescu, Dragoş [Bucharest University Hospital, Department of Orthopedics and Traumatology, Bucharest (Romania); Grumezescu, Valentina [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Lasers Department, National Institute for Lasers, Plasma & Radiation Physics, Magurele, Bucharest (Romania); Andronescu, Ecaterina [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Holban, Alina Maria [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Microbiology Immunology Department, Faculty of Biology, University of Bucharest, 1–3 Portocalelor Lane, Sector 5, 77206 Bucharest (Romania); Research Institute of the University of Bucharest –ICUB, 91-95 Splaiul Independentei, 050095 Bucharest (Romania); Grumezescu, Alexandru Mihai, E-mail: grumezescu@yahoo.com [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Socol, Gabriel [Lasers Department, National Institute for Lasers, Plasma & Radiation Physics, Magurele, Bucharest (Romania); Oprea, Alexandra Elena [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest (Romania); Rădulescu, Marius [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1–7 Polizu Street, 011061 Bucharest (Romania); and others

2016-06-30

Graphical abstract: - Highlights: • HAp/PLGA thin coatings by Matrix Assisted Pulsed Laser Evaporation. • Anti-adherent coating on medical surfaces against S. aureus and P. aeruginosa colonization. • Coatings with potential applications in implant osseointegration. - Abstract: In this study we aimed to obtain functionalized thin films based on hydroxyapatite/poly(lactic-co-glycolic acid) (HAp/PLGA) containing ceftriaxone/cefuroxime antibiotics (ATBs) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The prepared thin films were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-Ray diffraction (XRD), selected area electron diffraction (SAED), and infra red (IR) analysis. HAp/PLGA/ATBs thin films sustained the growth of human osteoblasts, proving their good biocompatibility. The microscopic evaluation and the culture-based quantitative assay of the E. coli biofilm development showed that the thin films inhibited the initial step of microbial attachment as well as the subsequent colonization and biofilm development on the respective surfaces. This study demonstrates that MAPLE technique could represent an appealing technique for the fabrication of antibiotics-containing polymeric implant coatings. The bioevaluation results recommend this type of surfaces for the prevention of bone implant microbial contamination and for the enhanced stimulation of the implant osseointegration process.

Development and characterization of multi-element doped hydroxyapatite bioceramic coatings on metallic implants for orthopedic applications

International Nuclear Information System (INIS)

Furko, M.; Havasi, V.; Kónya, Z.; Grünewald, D.; Detsch, R.; Boccaccini, A.R.; Balázsi, C.

2018-01-01

Multi-element modified bioactive hydroxyapatite bioceramic (mHAp) coatings were successfully developed onto surgical grade titanium alloy material (Ti6Al4V). The coatings were prepared by pulse current deposition from electrolyte containing adequate amounts of calcium nitrate and ammonium dihydrogen phosphate at 70C. The pure HAp layer was doped and co-deposited with Ag, Zn, Mg, Sr ions. The biocompatible properties of layers were investigated by seeding osteoblast-like MG-63 cells onto the samples’ surface. The biocompatible measurements revealed enhanced bioactivity of modified HAp compared to uncoated implant materials and pure bioceramic coating. The morphology and structure of coatings and cells were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) as well as FT-IR and XRD measurements. The biodegradable properties of samples were investigated by electrochemical potentiodynamic measurements. [es

Carbon foam/hydroxyapatite coating for carbon/carbon composites: Microstructure and biocompatibility

Energy Technology Data Exchange (ETDEWEB)

Zhang, Leilei, E-mail: zhangleilei1121@aliyun.com; Li, Hejun; Li, Kezhi; Zhang, Shouyang; Lu, Jinhua; Li, Wei; Cao, Sheng; Wang, Bin

2013-12-01

To improve the surface biocompatibility of carbon/carbon composites, a carbon foam/hydroxyapatite coating was applied using a combination method of slurry procedure and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The biocompatibility of the carbon foam/hydroxyapatite coating was investigated by osteoblast-like MG63 cell culture tests. The results showed that the carbon foam could provide a large number of pores on the surface of carbon/carbon composites. The hydroxyapatite crystals could infiltrate into the pores and form the carbon foam/hydroxyapatite coating. The coating covered the carbon/carbon composites fully and uniformly with slice morphology. The cell response tests showed that the MG63 cells on carbon foam/hydroxyapatite coating had a better cell adhesion and cell proliferation than those on uncoated carbon/carbon composites. The carbon foam/hydroxyapatite coatings were cytocompatible and were beneficial to improve the biocompatibility. The approach presented here may be exploited for fabrication of carbon/carbon composite implant surfaces.

Carbon foam/hydroxyapatite coating for carbon/carbon composites: Microstructure and biocompatibility

International Nuclear Information System (INIS)

Zhang, Leilei; Li, Hejun; Li, Kezhi; Zhang, Shouyang; Lu, Jinhua; Li, Wei; Cao, Sheng; Wang, Bin

2013-01-01

To improve the surface biocompatibility of carbon/carbon composites, a carbon foam/hydroxyapatite coating was applied using a combination method of slurry procedure and ultrasound-assisted electrochemical deposition procedure. The morphology, microstructure and chemical composition of the coating were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. The biocompatibility of the carbon foam/hydroxyapatite coating was investigated by osteoblast-like MG63 cell culture tests. The results showed that the carbon foam could provide a large number of pores on the surface of carbon/carbon composites. The hydroxyapatite crystals could infiltrate into the pores and form the carbon foam/hydroxyapatite coating. The coating covered the carbon/carbon composites fully and uniformly with slice morphology. The cell response tests showed that the MG63 cells on carbon foam/hydroxyapatite coating had a better cell adhesion and cell proliferation than those on uncoated carbon/carbon composites. The carbon foam/hydroxyapatite coatings were cytocompatible and were beneficial to improve the biocompatibility. The approach presented here may be exploited for fabrication of carbon/carbon composite implant surfaces.

Mechanical Properties of Chitosan-Starch Composite Filled Hydroxyapatite Micro- and Nanopowders

Directory of Open Access Journals (Sweden)

Jafar Ai

2011-01-01

Full Text Available Hydroxyapatite is a biocompatible ceramic and reinforcing material for bone implantations. In this study, Starch-chitosan hydrogel was produced using the oxidation of starch solution and subsequently cross-linked with chitosan via reductive alkylation method (weight ratio (starch/chitosan: 0.38. The hydroxyapatite micropowders and nanopowders synthesized by sol-gel method (10, 20, 30, 40 %W were composited to hydrogels and were investigated by mechanical analysis. The results of SEM images and Zetasizer experiments for synthesized nanopowders showed an average size of 100 nm. The nanoparticles distributed as uniform in the chitosan-starch film. The tensile modulus increased for composites containing hydroxyapatite nano-(size particle: 100 nanometer powders than composites containing micro-(size particle: 100 micrometer powders. The swelling percentage decreased for samples containing hydroxyapatite nanopowder than the micropowders. These nanocomposites could be applied for hard-tissue engineering.

Effects of combined hydroxyapatite and human platelet rich plasma on bone healing in rabbit model: radiological, macroscopical, hidtopathological and biomechanical evaluation.

Science.gov (United States)

Oryan, A; Meimandi Parizi, A; Shafiei-Sarvestani, Z; Bigham, A S

2012-12-01

Hydroxyapatite is an osteoconductive material used as a bone graft extender and exhibits excellent biocompatibility with soft tissues such as skin, muscle and gums, making it an ideal candidate for orthopedic and dental implants or components of implants. Synthetic hydroxyapatite has been widely used in repair of hard tissues, and common uses include bone repair, bone augmentation, as well as coating of implants or acting as fillers in bone or teeth. On the other hand, human platelet rich plasma (hPRP) has been used as a source of osteoinductive factor. A combination of hPRP and hydroxyapatite is expected to create a composite with both osteoconductive and osteoinductive properties. This study examined the effect of a combination of hydroxyapatite and hPRP on osteogenesis in vivo, using rabbit model bone healing. A critical size defect of 10 mm long was created in the radial diaphysis of 36 rabbit and either supplied with hydroxyapatite-human PRP or hydroxyapatite or was left empty (control group). Radiographs of each forelimb were taken postoperatively on 1st day and then at the 2nd, 4th, 6th and 8th weeks post injury to evaluate bone formation, union and remodeling of the defect. The operated radiuses of half of the animals in each group were removed on 56th postoperative day and were grossly and histopathologically evaluated. In addition, biomechanical test was conducted on the operated and normal forearms of the other half of the animals of each group. This study demonstrated that hydroxyapatite-humanPRP, could promote bone regeneration in critical size defects with a high regenerative capacity. The results of the present study demonstrated that hydroxyapatite-hPRP could be an attractive alternative for reconstruction of the major diaphyseal defects of the long bones in animal models.

Ex vivo evaluation of ferromagnetism for metallic ocular and middle-ear prostheses exposed to a 1.5-T MR imager

International Nuclear Information System (INIS)

Shellock, F.G.; Schatz, C.; Shelton, C.; Brown, B.

1990-01-01

This paper determines ferromagnetism by measuring deflection angles for nine different metallic ocular and middle-ear biomedical implants exposed to a 1.5-T MR imager. Deflection angles were determined at the bore of a 1.5-t MR imager for two ocular (Fatio eyelid wire 0.008, Fatio eyelid wire 0.01) and seven middle-ear (House tantalum single loop, House tantalum double loop, IRP, Schuknecht tef-wire piston, Austin tytan piston, McGee piston, Robinson stapes prosthesis) biomedical implants. A previously described, standardized methodology was used to measure deflection angles. Deflection angles for the biomedical implants were 90 degrees for the first ocular implant, over 90 degrees for the second, and 0 degrees (no deflection measured) for the seven middle-ear implants

The evaluation of hydroxyapatite (HA) coated and uncoated porous tantalum for biomedical material applications

International Nuclear Information System (INIS)

Safuan, Nadia; Sukmana, Irza; Kadir, Mohammed Rafiq Abdul; Noviana, Deni

2014-01-01

Porous tantalum has been used as an orthopedic implant for bone defects as it has a good corrosion resistance and fatigue behaviour properties. However, there are some reports on the rejection of porous Ta after the implantation. Those clinical cases refer to the less bioactivity of metallic-based materials. This study aims to evaluate hydroxyapatite coated and uncoated porous Tantalum in order to improve the biocompatibility of porous tantalum implant and osseointegration. Porous tantalum was used as metallic-base substrate and hydroxyapatite coating has been done using plasma-spraying technique. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) techniques were utilizes to investigate the coating characteristics while Confocal Raman Microscopy to investigate the interface and image. The effect of coating to the corrosion behaviour was assessed by employing potentiodynamic polarization tests in simulated body fluid at 37±1 °C. Based on SEM and FESEM results, the morphologies as well the weight element consists in the uncoated and hydroxyapatite coated porous tantalum were revealed. The results indicated that the decrease in corrosion current density for HA coated porous Ta compared to the uncoated porous Ta. This study concluded that by coating porous tantalum with HA supports to decrease the corrosion rate of pure porous.

The Evaluation of Hydroxyapatite (HA) Coated and Uncoated Porous Tantalum for Biomedical Material Applications

Science.gov (United States)

Safuan, Nadia; Sukmana, Irza; Kadir, Mohammed Rafiq Abdul; Noviana, Deni

2014-04-01

Porous tantalum has been used as an orthopedic implant for bone defects as it has a good corrosion resistance and fatigue behaviour properties. However, there are some reports on the rejection of porous Ta after the implantation. Those clinical cases refer to the less bioactivity of metallic-based materials. This study aims to evaluate hydroxyapatite coated and uncoated porous Tantalum in order to improve the biocompatibility of porous tantalum implant and osseointegration. Porous tantalum was used as metallic-base substrate and hydroxyapatite coating has been done using plasma-spraying technique. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) techniques were utilizes to investigate the coating characteristics while Confocal Raman Microscopy to investigate the interface and image. The effect of coating to the corrosion behaviour was assessed by employing potentiodynamic polarization tests in simulated body fluid at 37±1 °C. Based on SEM and FESEM results, the morphologies as well the weight element consists in the uncoated and hydroxyapatite coated porous tantalum were revealed. The results indicated that the decrease in corrosion current density for HA coated porous Ta compared to the uncoated porous Ta. This study concluded that by coating porous tantalum with HA supports to decrease the corrosion rate of pure porous.

Macroporous hydroxyapatite bioceramics by solid freeform fabrication: towards custom implants

CSIR Research Space (South Africa)

Richter, PW

1999-08-01

Full Text Available structure that would be impossible to make by conventional manufacturing methods. Application of this technology to the manufacture of macro porous hydroxyapatite bio ceramics for bone substitute applications is discussed. A new design is described...

Graft shrinkage and survival rate of implants after sinus floor elevation using a nanocrystalline hydroxyapatite embedded in silica gel matrix: a 1-year prospective study.

Science.gov (United States)

El Hage, Marc; Abi Najm, Semaan; Bischof, Mvark; Nedir, Rabah; Carrel, Jean-Pierre; Bernard, Jean-Pierre

2012-06-01

The aims of this study were (1) to evaluate the vertical shrinkage percentage of nanocrystalline hydroxyapatite embedded in silica gel used for maxillary sinus floor elevation (SFE) and (2) to determine the survival rate of the implants 1 year after placement in the healed grafted sinuses. Eleven maxillary sinuses were augmented in eight patients with NanoBone. After a healing period averaging 14.42 months, 19 implants were placed and followed up with clinical and radiographic evaluation. Panoramic radiographs were taken immediately after SFE and at 12 months after grafting. Measurements of changes in height were made by a computerized measuring technique using an image editing software. The mean graft height shrinkage percentage at 12 months after surgery was 8.84% (±5.32). One implant was lost before loading. All the 18 remaining osseointegrated implants received the prosthetic rehabilitation and were controlled after 3 months of functional loading. The implant survival rate at the 1-year interval was 94.74%. A 100% NanoBone alloplastic graft used in lateral SFE procedures presented limited height shrinkage. Implants placed in these grafted sinuses showed survival rates similar to those found in published data. These results should be interpreted cautiously considering the study's reduced sample size.

Composite biocompatible hydroxyapatite-silk fibroin coatings for medical implants obtained by Matrix Assisted Pulsed Laser Evaporation

International Nuclear Information System (INIS)

Miroiu, F.M.; Socol, G.; Visan, A.; Stefan, N.; Craciun, D.; Craciun, V.; Dorcioman, G.; Mihailescu, I.N.; Sima, L.E.; Petrescu, S.M.; Andronie, A.; Stamatin, I.; Moga, S.; Ducu, C.

2010-01-01

The aim of this study was to obtain biomimetic inorganic-organic thin films as coatings for metallic medical implants. These contain hydroxyapatite, the inorganic component of the bony tissues, and a natural biopolymer - silk fibroin - added in view to induce the surface functionalization. Hydroxyapatite (HA), silk fibroin (FIB) and composite HA-FIB films were obtained by Matrix Assisted Pulsed Laser Evaporation (MAPLE) in order to compare their physical and biological performances as coatings on metallic prostheses. We used an excimer laser source (KrF*, λ = 248 nm, τ = 25 ns) operated at 10 Hz repetition rate. Coatings were deposited on quartz, Si and Ti substrates and then subjected to physical (FTIR, XRD, AFM, SEM) analyses, correlated with the results of the cytocompatibility in vitro tests. The hybrid films were synthesized from frozen targets of aqueous suspensions with 3:2 or 3:4 weight ratio of HA:FIB. An appropriate stoichiometric and functional transfer was obtained for 0.4-0.5 J/cm 2 laser fluence. FTIR spectra of FIB and HA-FIB films exhibited distinctive absorption maxima, in specific positions of FIB random coil form: 1540 cm -1 amide II, 1654 cm -1 amide I, 1243 cm -1 amide III, while the peak from 1027 cm -1 appeared only for HA and composite films. Osteosarcoma SaOs2 cells cultured 72 h on FIB and HA-FIB films showed increased viability, good spreading and normal cell morphology. The well-elongated, flattened cells are a sign of an appropriate interaction with the MAPLE FIB and composite HA-FIB coatings.

Composite biocompatible hydroxyapatite-silk fibroin coatings for medical implants obtained by Matrix Assisted Pulsed Laser Evaporation

Energy Technology Data Exchange (ETDEWEB)

Miroiu, F.M., E-mail: marimona.miroiu@inflpr.ro [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Socol, G.; Visan, A.; Stefan, N.; Craciun, D.; Craciun, V.; Dorcioman, G.; Mihailescu, I.N. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Sima, L.E.; Petrescu, S.M. [Institute of Biochemistry, Romanian Academy, 296 Splaiul Independentei, 060031 Bucharest (Romania); Andronie, A.; Stamatin, I. [3Nano-SAE Alternative Energy Sources-University of Bucharest, Faculty of Physics, 409 Atomistilor Street, RO-77125, Magurele-Ilfov (Romania); Moga, S.; Ducu, C. [University of Pitesti, Targul din Vale Str, no. 1, 110040 Pitesti (Romania)

2010-05-25

The aim of this study was to obtain biomimetic inorganic-organic thin films as coatings for metallic medical implants. These contain hydroxyapatite, the inorganic component of the bony tissues, and a natural biopolymer - silk fibroin - added in view to induce the surface functionalization. Hydroxyapatite (HA), silk fibroin (FIB) and composite HA-FIB films were obtained by Matrix Assisted Pulsed Laser Evaporation (MAPLE) in order to compare their physical and biological performances as coatings on metallic prostheses. We used an excimer laser source (KrF*, {lambda} = 248 nm, {tau} = 25 ns) operated at 10 Hz repetition rate. Coatings were deposited on quartz, Si and Ti substrates and then subjected to physical (FTIR, XRD, AFM, SEM) analyses, correlated with the results of the cytocompatibility in vitro tests. The hybrid films were synthesized from frozen targets of aqueous suspensions with 3:2 or 3:4 weight ratio of HA:FIB. An appropriate stoichiometric and functional transfer was obtained for 0.4-0.5 J/cm{sup 2} laser fluence. FTIR spectra of FIB and HA-FIB films exhibited distinctive absorption maxima, in specific positions of FIB random coil form: 1540 cm{sup -1} amide II, 1654 cm{sup -1} amide I, 1243 cm{sup -1} amide III, while the peak from 1027 cm{sup -1} appeared only for HA and composite films. Osteosarcoma SaOs2 cells cultured 72 h on FIB and HA-FIB films showed increased viability, good spreading and normal cell morphology. The well-elongated, flattened cells are a sign of an appropriate interaction with the MAPLE FIB and composite HA-FIB coatings.

Bioactivity and osteointegration of hydroxyapatite-coated stainless steel and titanium wires used for intramedullary osteosynthesis.

Science.gov (United States)

Popkov, Arnold V; Gorbach, Elena N; Kononovich, Natalia A; Popkov, Dmitry A; Tverdokhlebov, Sergey I; Shesterikov, Evgeniy V

2017-08-01

A lot of research was conducted on the use of various biomaterials in orthopedic surgery. Our study investigated the effects of nanostructured calcium-phosphate coating on metallic implants introduced into the bone marrow canal. Stainless steel or titanium 2-mm wires (groups 1 and 2, respectively), and hydroxyapatite-coated stainless steel or titanium wires of the same diameter (groups 3 and 4, respectively) were introduced into the tibial bone marrow canal of 20 dogs (each group = 5 dogs). Hydroxyapatite coating was deposited on the wires with the method of microarc oxidation. Light microscopy to study histological diaphyseal transverse sections, scanning electron microscopy to study the bone marrow area around the implant and an X-ray electron probe analyzer to study the content of calcium and phosphorus were used to investigate bioactivity and osteointegration after a four weeks period. Osteointegration was also assessed by measuring wires' pull-off strength with a sensor dynamometer. Bone formation was observed round the wires in the bone marrow canal in all the groups. Its intensity depended upon the features of wire surfaces and implant materials. Maximum percentage volume of trabecular bone was present in the bone marrow canals of group 4 dogs that corresponded to a mean of 27.1 ± 0.14%, while it was only 6.7% in group 1. The coating in groups 3 and 4 provided better bioactivity and osteointegration. Hydroxyapatite-coated titanium wires showed the highest degree of bone formation around them and greater pull-off strength. Nanostructured hydroxyapatite coating of metallic wires induces an expressed bone formation and provides osteointegration. Hydroxyapatite-coated wires could be used along with external fixation for bone repair enhancement in diaphyseal fractures, management of osteogenesis imperfecta and correction of bone deformities in phosphate diabetes.

Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

Energy Technology Data Exchange (ETDEWEB)

Parcharoen, Yardnapar [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Kajitvichyanukul, Puangrat [Center of Excellence on Environmental Research and Innovation, Faculty of Engineering, Naresuan University, Phitsanulok (Thailand); Sirivisoot, Sirinrath [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Termsuksawad, Preecha, E-mail: preecha.ter@kmutt.ac.th [Division of Materials Technology, School of Energy, Environment and Materials, King Mongkut' s University of Technology Thonburi, 126 Pracha Uthit Rd., Bang Mod, ThungKhru, Bangkok 10140 (Thailand)

2014-08-30

Highlights: • We found that different anodization time of titanium significantly effects on nanotube length which further impacts adhesion strength of hydroxyapatite coating layers. • Adhesion strength of Hydroxyapatite (HA) coated on titanium dioxide nanotubes is better than that of HA coated on titanium plate. • Hydroxyapatite coated on titanium dioxide nanotubes showed higher cell density and better spreading of MC3T3-E1 cells (bone-forming cells) than that coated on titanium plate surface. - Abstract: Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO{sub 2}) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO{sub 2} nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH{sub 4}F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO{sub 2} nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO{sub 2} nanotubes were found when high viscous electrolyte, NH{sub 4}F in glycerol, was used. Negative voltage (−4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO{sub 2} nanotubes was significantly increased by times. The TiO{sub 2} nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO{sub 2} nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that

HA-Coated Implant

DEFF Research Database (Denmark)

Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

2014-01-01

of improving the fixation of implants. Of these, hydroxyapatite (HA) is the most widely used and most extensively investigated. HA is highly osseoconductive, and the positive effect is well documented in both basic and long-term clinical research [1–6]. This chapter describes experimental and clinical studies...

Investigation on the effect of collagen and vitamins on biomimetic hydroxyapatite coating formation on titanium surfaces.

Science.gov (United States)

Ciobanu, Gabriela; Ciobanu, Octavian

2013-04-01

This study uses an in vitro experimental approach to investigate the roles of collagen and vitamins in regulating the deposition of hydroxyapatite layer on the pure titanium surface. Titanium implants were coated with a hydroxyapatite layer under biomimetic conditions by using a supersaturated calcification solution (SCS), modified by adding vitamins A and D3, and collagen. The hydroxyapatite deposits on titanium were investigated by means of scanning electron microscopy (SEM) coupled with X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results obtained have shown that hydroxyapatite coatings were produced in vitro under vitamins and collagen influence. Copyright © 2012 Elsevier B.V. All rights reserved.

Coralline hydroxyapatite bone graft substitutes in a canine metaphyseal defect model: Radiographic-biomechanical correlation

International Nuclear Information System (INIS)

Sartoris, D.J.; Resnick, D.; Holmes, R.E.; Tencer, A.F.; Texas Univ., Dallas; Mooney, V.

1986-01-01

Radiographic and biomechanical assessment of a new type of bone graft substitute derived from reef-building sea coral was performed in a canine metaphyseal defect model. Blocks of this material and autogenous iliac crest graft were implanted, respectively, into the right and left proximal tibial metaphyses of eight dogs. Qualitative and quantitative radiographic evaluation was performed in the immediate postoperative period and at 6 months after surgery. Biomechanical testing was carried out on all grafts following harvest at 6 months, as well as on nonimplanted coralline hydroxyapatite and autogenous iliac cancellous bone. In contrast to autografts, incorporation of coralline implants was characterized by predictable osseous growth and apposition with preservation of intrinsic architecture. Greater percent increase in radiography density, higher ultimate compressive strength, and lower stiffness with incorporation were documented advantages of coralline hydroxyapatite over autogenous graft. Densitometric measurements correlated moderately with strength for both types of graft material (r=0.65). These promising results have important implications to the clinical application of coralline hydroxyapatite bone graft substitutes as an alternative to autogenous grafting. (orig.)

In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants.

Science.gov (United States)

Sutha, S; Kavitha, K; Karunakaran, G; Rajendran, V

2013-10-01

A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58-1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. Copyright © 2013 Elsevier B.V. All rights reserved.

In vitro characterizations of mesoporous hydroxyapatite as a controlled release delivery device for VEGF in orthopedic applications.

Science.gov (United States)

Poh, Chye Khoon; Ng, Suxiu; Lim, Tee Yong; Tan, Hark Chuan; Loo, Joachim; Wang, Wilson

2012-11-01

Following bone implant surgery, prolonged ischemic conditions at the implant site often result in postsurgical complications like failure of osseointegration at the bone-implant interface which can lead to implant failure. Thus, restoration of the vascular supply is paramount to the proper development of the bone. High surface area mesostructured materials have been shown to be attractive candidates for bone regeneration to enhance cell adhesion and cell proliferation. This study uses hydroxyapatite, a naturally occurring mineral in the bone, fabricated to a range of suitable pore sizes, infused with vascular endothelial growth factor (VEGF), to be progressively released to stimulate revascularization. In this study, several characterizations including nitrogen adsorption analysis, Fourier-transformed infrared spectroscopy, X-ray diffraction, field emission scanning electron microscope, and transmission electron microscope were used to evaluate the synthesized mesoporous hydroxyapatite (MHA). The results showed that MHA can gradually release VEGF for enhancing revascularization, which is beneficial for orthopedic applications. Copyright © 2012 Wiley Periodicals, Inc.

Bone Implant Interface Investigation by Synchrotron Radiation X-Ray Microfluorescence

International Nuclear Information System (INIS)

Calasans-Maia, M.; Sales, E.; Lopes, R. T.; Granjeiro, J. M.; Lima, I.

2010-01-01

Zinc is known to play a relevant role in growth and development; it has stimulatory effects on in vitro and in vivo bone formation and an inhibitory effect on in vitro osteoclastic bone resorption. The inorganic component of the bone tissue is nonstoichiometric apatite; changes in the composition of hidroxyapatite are subject of studies in order to improve the tissue response after implantation. The objective of this study was to investigate the effect of 0.5% zinc-containing hydroxyapatite in comparison to hydroxyapatite on osseous repair of rabbit's tibia. Cylinders (2x6 mm) of both materials were produced according to the specification of the International Organization for Standardization. Ethics Commission on Teaching and Research in Animals approved this project (HUAP-195/06). Fifteen White New Zealand rabbits were submitted to general anesthesia and two perforations (2 mm) were made in each tibia for implantation of zinc-containing hydroxyapatite cylinders (left tibia) and hydroxyapatite cylinders (right tibia). After 1, 2 and 4 weeks, the animals were killed and one fragment of each tibia with the cylinder was collected and embedded in a methacrylate-based resin and cut into slices (∼200 μm thickness), parallel to the implant's long axis with a precision diamond saw for Synchrotron Radiation X-ray Microfluorescence investigation. The accomplishment of the standard procedures helped the planning, execution and the comparative analysis of the results. The chemical and physical properties of the biomaterials were modified after its implantation and the incorporation of zinc. Both materials are biocompatible and promote osteoconduction and favored bone repair.

Tensile properties and microstructural analysis of spheroidized hydroxyapatite-poly (etheretherketone) biocomposites

International Nuclear Information System (INIS)

Abu Bakar, M.S.; Cheang, P.; Khor, K.A.

2003-01-01

Poly(etheretherketone) or PEEK, is a high performance thermoplastic possessing exceptional mechanical properties, high temperature durability, good chemical and fatigue resistance. These coupled with its ability to withstand sterilization treatment, make it a preferred material for biomedical applications. This study examines the benefit of incorporating hydroxyapatite particulates in poly(etheretherketone) for possible usage as bone analogue materials. Flame spheroidized hydroxyapatite (FSHA) were incorporated into semi-crystalline poly(etheretherketone) polymer through a series of processes comprising melt compounding, granulating and injection molding. Biocomposites with high hydroxyapatite loading of up to 40 vol.% were processed successfully using this technique. Scanning electron microscopy (SEM) revealed fair dispersion and distribution of hydroxyapatite particles within the polymer matrix. The series of composites were characterized in terms of tensile and microhardness properties. Microstructural analysis was also carried out to correlate the structure-property relationship of the composite. The dependency of tensile properties such as modulus, strength and strain to fracture as well as the micro-hardness on the volume percentage of hydroxyapatite were investigated. By varying the amount of hydroxyapatite particles in the composite, a wide range of mechanical properties were obtained. In general, the tensile modulus and microhardness increased, while strength and strain to fracture decreased correspondingly with progressive addition of hydroxyapatite particles. The composite system under investigation also exhibited mechanical properties matching those of human bone. With hydroxyapatite loading beyond 30 vol.%, the modulus were within the bounds of the human cortical bone. Findings from this study suggest that this bioactive composite system have the potential as an alternative implant material for orthopaedic application

The impact of combined oral contraceptives on ocular tissues: a review of ocular effects

Directory of Open Access Journals (Sweden)

Marilita M. Moschos

2017-10-01

Full Text Available The aim of this manuscript is to review the action and adverse effects of combined oral contraceptives (COCs on ocular tissues. The percentage of unwanted pregnancies and the subsequent abortions make contraception crucial worldwide. Over 100 million women around the world use common contraceptive methods, including intrauterine devices, combined estrogen and progestin oral contraceptives, as well as progestin only preparations (oral contraceptives, implants or injections. COCs are widely used for contraception, but they are also indicated in menorrhagia, endometriosis, acne and hirsutism, fibroid uterus and premenstrual syndrome. However, they have been associated with high rates of cardiovascular events, venous thromboembolic disease, ischemic strokes and breast cancer. The incidence of COCs-related ocular complications is estimated to be 1 in 230 000, including dry eye symptoms, corneal edema, lens opacities and retinal neuro-ophthalmologic or vascular complications. We may infer that the serious ocular complications of COCs can be prevented by eliminating the estrogen dosage and choosing third-generation progestins. In any case, doctors should take into consideration the systemic and ocular history of the patients before selecting any method of contraception.

Examination of Sol-Gel Derived Hydroxyapatite Enhanced with Silver Nanoparticles using OCT and Raman Spectroscopy

OpenAIRE

Głowacki Maciej J.; Gnyba Marcin; Strąkowska Paulina; Gardas Mateusz; Kraszewski Maciej; Trojanowski Michał; Strąkowski Marcin R.

2017-01-01

Hydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements of HAp molecular composition and solvent evaporati...

Retention of albumin labelled with I-125 in the bio mineral hydroxyapatite

International Nuclear Information System (INIS)

Badillo A, V.E.; Bugarin C, A.; Monroy G, F.

2003-01-01

The demands of materials for the health in the entire world, especially of the odontological and traumatological sectors make every time to be but studied the hydroxyapatite (HAP) and their biocompatibility with the alive beings. The hydroxyapatite is considered as one of the inorganic exchangers by excellence, for what the fixation of ions and molecules have been widely studied and at the moment it is one of the materials of greater acceptance like implant. The surface of the material of implant is in intimate contact with the live tissue and its biocompatibility is determined in great measure by those surface properties of the bio material, which have a direct effect in the cellular response of the material. After administering the implant, the proteins are immediately adsorbed in the surface of the bio mineral. Specifically, the proteins of the blood are considered as key pieces to determine the acceptance of implants in alive beings. The adsorption of proteins it depends on the physicochemical properties of the material as well as of the environment composition. The surface properties of the HAP are relevant in the adsorption mechanisms of the proteins. In this work, it is reported the adsorption of the labelled with I-125 albumin protein and in function of two important physicochemical parameters: the pH value of the of the solution and the chemical nature of the solution; to see the influence of this last, its were studied three electrolytes NaF, NaCl and NaH 2 PO 4 . The existence of the active sites of hydroxyapatite surface, it is key piece in the interpretation of the fixation of the albumin protein in function also of their acid-base properties. (Author)

Multiple ocular abnormalities associated with trisomy 4p.

Science.gov (United States)

Hong, Samin; Kang, Sung Yong; Seong, Gong Je; Shin, Joo Youn; Kim, Chan Yun

2008-01-01

Ocular features associated with trisomy 4p have rarely been described. The authors have experienced multiple ocular abnormalities (bilateral cataracts, posterior synechiae, and posterior segment changes) associated with this chromosomal abnormality. It was presumed that these intraocular findings might be associated with the previous inflammatory process. In the current case, the patient recovered some useful vision after surgical removal of cataracts and intraocular lens implantations in both eyes. A detailed ophthalmic examination for patients with the autosomal imbalance is recom-mended.

Enhanced osseous implant fixation with strontium-substituted bioactive glass coating

NARCIS (Netherlands)

Newman, S.D.; Lotfibakhshaiesh, N.; O'Donnell, M.; Walboomers, X.F.; Horwood, N.; Jansen, J.A.; Amis, A.A.; Cobb, J.P.; Stevens, M.M.

2014-01-01

The use of endosseous implants is firmly established in skeletal reconstructive surgery, with rapid and permanent fixation of prostheses being a highly desirable feature. Implant coatings composed of hydroxyapatite (HA) have become the standard and have been used with some success in prolonging the

The Role of Bioceramics Coating in Dental Implant Reliability and Success

Directory of Open Access Journals (Sweden)

Mortazavi V

2000-05-01

Full Text Available Characterization of bioceramics coating and evaluation of the influence of kind of coating on"nthe implantation has been developed in recent years."nDifferent bioceramics coating like calcium phosphate, hydroxyapatite, fluorapatite and bioglass were"ncoated on dental and orthopedic implants. In-vitro and in-vivo experiments were done for evolution of"nimplant success and reliability and study of factors, which may influence the results."nResearches indicate that different bioceramic coating may affect the bone bonding mechanism."nBiodegredable calcium phosphate coating can be resorbed and be replaced with bone tissues."nHydroxyapatite cause earlier stabilization of dental implant in surrounding bone (biological fixation and"nreduce healing time. Bioglass can protect substrate and provide interfacial attachment to bone.

Preparation and mechanical properties of photo-crosslinked poly(trimethylene carbonate) and nano-hydroxyapatite composites.

Science.gov (United States)

Geven, Mike A; Barbieri, Davide; Yuan, Huipin; de Bruijn, Joost D; Grijpma, Dirk W

2015-01-01

Composite materials of photo-crosslinked poly(trimethylene carbonate) and nanoscale hydroxyapatite were prepared and their mechanical characteristics for application as orbital floor implants were assessed. The composites were prepared by solvent casting poly(trimethylene carbonate) macromers with varying amounts of nano-hydroxyapatite and subsequent photo-crosslinking. The incorporation of the nano-hydroxyapatite into the composites was examined by thermogravimetric analysis, scanning electron microscopy and gel content measurements. The mechanical properties were investigated by tensile testing and trouser tearing experiments. Our results show that nano-hydroxyapatite particles can readily be incorporated into photo-crosslinked poly(trimethylene carbonate) networks. Compared to the networks without nano-hydroxyapatite, incorporation of 36.3 wt.% of the apatite resulted in an increase of the E modulus, yield strength and tensile strength from 2.2 MPa to 51 MPa, 0.5 to 1.4 N/mm2 and from 1.3 to 3.9 N/mm2, respectively. We found that composites containing 12.4 wt.% nano-hydroxyapatite had the highest values of strain at break, toughness and average tear propagation strength (376% , 777 N/mm2 and 3.1 N/mm2, respectively).

Poly(vinyl alcohol) hydrogel coatings with tunable surface exposure of hydroxyapatite

Science.gov (United States)

Moreau, David; Villain, Arthur; Ku, David N; Corté, Laurent

2014-01-01

Insufficient bone anchoring is a major limitation of artificial substitutes for connective osteoarticular tissues. The use of coatings containing osseoconductive ceramic particles is one of the actively explored strategies to improve osseointegration and strengthen the bone-implant interface for general tissue engineering. Our hypothesis is that hydroxyapatite (HA) particles can be coated robustly on specific assemblies of PVA hydrogel fibers for the potential anchoring of ligament replacements. A simple dip-coating method is described to produce composite coatings made of microscopic hydroxyapatite (HA) particles dispersed in a poly(vinyl alcohol) (PVA) matrix. The materials are compatible with the requirements for implant Good Manufacturing Practices. They are applied to coat bundles of PVA hydrogel fibers used for the development of ligament implants. By means of optical and electronic microscopy, we show that the coating thickness and surface state can be adjusted by varying the composition of the dipping solution. Quantitative analysis based on backscattered electron microscopy show that the exposure of HA at the coating surface can be tuned from 0 to over 55% by decreasing the weight ratio of PVA over HA from 0.4 to 0.1. Abrasion experiments simulating bone-implant contact illustrate how the coating cohesion and wear resistance increase by increasing the content of PVA relative to HA. Using pullout experiments, we find that these coatings adhere well to the fiber bundles and detach by propagation of a crack inside the coating. These results provide a guide to select coated implants for anchoring artificial ligaments. PMID:25482413

Poly(vinyl alcohol) hydrogel coatings with tunable surface exposure of hydroxyapatite.

Science.gov (United States)

Moreau, David; Villain, Arthur; Ku, David N; Corté, Laurent

2014-01-01

Insufficient bone anchoring is a major limitation of artificial substitutes for connective osteoarticular tissues. The use of coatings containing osseoconductive ceramic particles is one of the actively explored strategies to improve osseointegration and strengthen the bone-implant interface for general tissue engineering. Our hypothesis is that hydroxyapatite (HA) particles can be coated robustly on specific assemblies of PVA hydrogel fibers for the potential anchoring of ligament replacements. A simple dip-coating method is described to produce composite coatings made of microscopic hydroxyapatite (HA) particles dispersed in a poly(vinyl alcohol) (PVA) matrix. The materials are compatible with the requirements for implant Good Manufacturing Practices. They are applied to coat bundles of PVA hydrogel fibers used for the development of ligament implants. By means of optical and electronic microscopy, we show that the coating thickness and surface state can be adjusted by varying the composition of the dipping solution. Quantitative analysis based on backscattered electron microscopy show that the exposure of HA at the coating surface can be tuned from 0 to over 55% by decreasing the weight ratio of PVA over HA from 0.4 to 0.1. Abrasion experiments simulating bone-implant contact illustrate how the coating cohesion and wear resistance increase by increasing the content of PVA relative to HA. Using pullout experiments, we find that these coatings adhere well to the fiber bundles and detach by propagation of a crack inside the coating. These results provide a guide to select coated implants for anchoring artificial ligaments.

Preparation and mechanical properties of photo-crosslinked poly(trimethylene carbonate) and nano-hydroxyapatite composites

NARCIS (Netherlands)

Geven, Mike Alexander; Barbieri, D.; Yuan, Huipin; de Bruijn, Joost Dick; Grijpma, Dirk W.

2015-01-01

Composite materials of photo-crosslinked poly(trimethylene carbonate) and nanoscale hydroxyapatite were prepared and their mechanical characteristics for application as orbital floor implants were assessed. The composites were prepared by solvent casting poly(trimethylene carbonate) macromers with

Reactive hydroxyapatite fillers for pectin biocomposites.

Science.gov (United States)

Munarin, Fabiola; Petrini, Paola; Barcellona, Giulia; Roversi, Tommaso; Piazza, Laura; Visai, Livia; Tanzi, Maria Cristina

2014-12-01

In this work, a novel injectable biocomposite hydrogel is produced by internal gelation, using pectin as organic matrix and hydroxyapatite either as crosslinking agent and inorganic reinforcement. Tunable gelling kinetics and rheological properties are obtained varying the hydrogels' composition, with the final aim of developing systems for cell immobilization. The reversibility by dissolution of pectin-hydroxyapatite hydrogels is achieved with saline solutions, to possibly accelerate the release of the cells or active agents immobilized. Texture analysis confirms the possibility of extruding the biocomposites from needles with diameters from 20 G to 30 G, indicating that they can be implanted with minimally-invasive approaches, minimizing the pain during injection and the side effects of the open surgery. L929 fibroblasts entrapped in the hydrogels survive to the immobilization procedure and exhibit high cell viability. On the overall, these systems result to be suitable supports for the immobilization of cells for tissue regeneration applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Dosimetric measurement of scattered radiation from dental implants in simulated head and neck radiotherapy.

Science.gov (United States)

Wang, R; Pillai, K; Jones, P K

1998-01-01

The purpose of this study was to examine the dose enhancement at bone-implant interfaces from scattered radiation during simulated head and neck radiotherapy. Three cylindric implant systems with different compositions (pure titanium, titanium-aluminum-vanadium alloy, titanium coated with hydroxyapatite) and a high gold content transmandibular implant system (gold-copper-silver alloy) were studied. Extruded lithium fluoride single crystal chips were used as thermoluminescent material to measure radiation dose enhancement at 0, 1, and 2 mm from the bone-implant interface. The relative doses in buccal, lingual, mesial, and distal directions were also recorded and compared. The results indicated that the highest dose enhancement occurred at a distance of 0 mm from the bone-implant interface for all the implant systems studied. The transmandibular implants had higher scattered radiation than other groups at 0 mm and at 1 mm from the bone-implant interface. There was no significant difference of dose enhancement between buccal, lingual, mesial, and distal directions. Titanium implants coated with hydroxyapatite demonstrated the best results under the simulated irradiation.

Bisphosphonates enhance bacterial adhesion and biofilm formation on bone hydroxyapatite.

Science.gov (United States)

Kos, Marcin; Junka, Adam; Smutnicka, Danuta; Szymczyk, Patrycja; Gluza, Karolina; Bartoszewicz, Marzenna

2015-07-01

Because of the suspicion that bisphosphonates enhance bacterial colonization, this study evaluated adhesion and biofilm formation by Streptococcus mutans 25175, Staphylococcus aureus 6538, and Pseudomonas aeruginosa 14454 reference strains on hydroxyapatite coated with clodronate, pamidronate, or zoledronate. Bacterial strains were cultured on bisphosphonate-coated and noncoated hydroxyapatite discs. After incubation, nonadhered bacteria were removed by centrifugation. Biofilm formation was confirmed by scanning electron microscopy. Bacterial colonization was estimated using quantitative cultures compared by means with Kruskal-Wallis and post-hoc Student-Newman-Keuls tests. Modeling of the interactions between bisphosphonates and hydroxyapatite was performed using the Density Functional Theory method. Bacterial colonization of the hydroxyapatite discs was significantly higher for all tested strains in the presence of bisphosphonates vs. Adherence in the presence of pamidronate was higher than with other bisphosphonates. Density Functional Theory analysis showed that the protonated amine group of pamidronate, which are not present in clodronate or zoledronate, forms two additional hydrogen bonds with hydroxyapatite. Moreover, the reactive cationic amino group of pamidronate may attract bacteria by direct electrostatic interaction. Increased bacterial adhesion and biofilm formation can promote osteomyelitis, cause failure of dental implants or bisphosphonate-coated joint prostheses, and complicate bone surgery in patients on bisphosphonates. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Biocompatibility of Poly(ester amide (PEA Microfibrils in Ocular Tissues

Directory of Open Access Journals (Sweden)

Martina Kropp

2014-01-01

Full Text Available Drug delivery systems (DDS are able to deliver, over long periods of time, therapeutic concentrations of drugs requiring frequent administration. Two classes of DDS are available, biodegradable and non-biodegradable. The larger non-biodegradable implants ensure long-term delivery, but require surgical interventions. Biodegradable biomaterials are smaller, injectable implants, but degrade hydrolytically and release drugs in non-zero order kinetics, which is inefficient for long-term sustained drug release. Biodegradable poly(ester amides (PEAs may overcome these difficulties. To assess their ocular biocompatibility and long-term behavior, PEA fibrils were analyzed in vitro and in vivo. In vitro, incubation in vitreous humor changes to PEA structure, suggests degradation by surface erosion, enabling drug release with zero order kinetics. Clinical and histological analysis of PEA fibrils implanted subconjunctivally and intravitreally showed the absence of an inflammatory response or other pathological tissue alteration. This study shows that PEA fibrils are biocompatible with ocular environment and degrade by surface erosion.

Evaluation of porous gradient hydroxyapatite/zirconia composites for repair of lumbar vertebra defect in dogs.

Science.gov (United States)

Shao, Rong-Xue; Quan, Ren-Fu; Huang, Xiao-Long; Wang, Tuo; Xie, Shang-Ju; Gao, Huan-Huan; Wei, Xi-Cheng; Yang, Di-Sheng

2016-04-01

To evaluate the effects of porous gradient composites with hydroxyapatite/zirconia and autologous iliac in repair of lumbar vertebra body defects in dogs. (1) New porous gradient hydroxyapatite/zirconia composites were prepared using foam immersion, gradient compound and high temperature sintering; (2) A total of 18 adult beagle dogs, aged five to eight months and weighted 10-13 kg, were randomly assigned into two subgroups, which were implanted with new porous gradient hydroxyapatite/zirconia composites (subgroup A in 12) or autologous iliac bone (subgroup B in 6); (3) The post-operative data were analyzed and compared between the subgroups to repair the vertebral body defect by roentgenoscopy, morphology and biomechanics. The porosity of new porous gradient hydroxyapatite/zirconia composites is at 25 poles per inch, and the size of pores is at between 150 and 300 µm. The post-operative roentgenoscopy displayed that new-bone formation is increased gradually, and the interface between composites and host-bone becomes became blur, and the new-bone around the composites were integrated into host-bone at 24 weeks postoperatively in subgroup A. As to subgroup B, the resorption and restructure were found at six weeks after the surgery, and the graft-bone and host-bone have been integrated completely without obvious boundary at 24 weeks postoperatively. Histomorphologic study showed that the amount of bone within pores of the porous gradient hydroxyapatite/zirconia composites increased continuously with a prolonged implantation time, and that partial composites were degradated and replaced by new-bone trabeculae. There was no significant difference between subgroups (P > 0.05) in the ultimate compressive strengths. New porous gradient hydroxyapatite/zirconia composites can promote the repair of bony defect, and induce bone tissue to ingrow into the pores, which may be applied widely to the treatment of bony defect in the future. © The Author(s) 2016.

Investigation on the effect of collagen and vitamins on biomimetic hydroxyapatite coating formation on titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Ciobanu, Gabriela, E-mail: gciobanu03@yahoo.co.uk [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, Prof. dr. docent Dimitrie Mangeron Rd., no. 63, zip: 700050, Iasi (Romania); Ciobanu, Octavian [“Grigore T. Popa” University of Medicine and Pharmacy, Faculty of Medical Bioengineering, Universitatii Str., no. 16, zip: 700115, Iasi (Romania)

2013-04-01

This study uses an in vitro experimental approach to investigate the roles of collagen and vitamins in regulating the deposition of hydroxyapatite layer on the pure titanium surface. Titanium implants were coated with a hydroxyapatite layer under biomimetic conditions by using a supersaturated calcification solution (SCS), modified by adding vitamins A and D{sub 3}, and collagen. The hydroxyapatite deposits on titanium were investigated by means of scanning electron microscopy (SEM) coupled with X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results obtained have shown that hydroxyapatite coatings were produced in vitro under vitamins and collagen influence. - Highlights: ► Hydroxyapatite was grown on Ti using a modified supersaturated calcification solution (M-SCS). ► Vitamins (A and D3) and collagen in M-SCS have a significant effect on apatite precipitation. ► M-SCS stimulates a biomimetic apatite deposition with 0.5–1 μm thickness in a short time. ► Hydroxyapatite crystallites have thin plate morphologies and size below 1 μm.

Investigation on the effect of collagen and vitamins on biomimetic hydroxyapatite coating formation on titanium surfaces

International Nuclear Information System (INIS)

Ciobanu, Gabriela; Ciobanu, Octavian

2013-01-01

This study uses an in vitro experimental approach to investigate the roles of collagen and vitamins in regulating the deposition of hydroxyapatite layer on the pure titanium surface. Titanium implants were coated with a hydroxyapatite layer under biomimetic conditions by using a supersaturated calcification solution (SCS), modified by adding vitamins A and D 3 , and collagen. The hydroxyapatite deposits on titanium were investigated by means of scanning electron microscopy (SEM) coupled with X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results obtained have shown that hydroxyapatite coatings were produced in vitro under vitamins and collagen influence. - Highlights: ► Hydroxyapatite was grown on Ti using a modified supersaturated calcification solution (M-SCS). ► Vitamins (A and D3) and collagen in M-SCS have a significant effect on apatite precipitation. ► M-SCS stimulates a biomimetic apatite deposition with 0.5–1 μm thickness in a short time. ► Hydroxyapatite crystallites have thin plate morphologies and size below 1 μm

Alveolar bone repair with strontium- containing nanostructured carbonated hydroxyapatite

Directory of Open Access Journals (Sweden)

André Boziki Xavier do Carmo

2018-01-01

Full Text Available ABSTRACT Objective: This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA as bone substitute materials. Methods: Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group. After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. Results: The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05. We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039 in both groups. Conclusion: The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant

International Nuclear Information System (INIS)

Akmal, Muhammad; Raza, Ahmad; Khan, Muhammad Mudasser; Khan, M. Imran; Hussain, Muhammad Asif

2016-01-01

Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6 vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10 h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3 h at 1325 K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi 2 , Ni 3 Ti, and Ni 4 Ti 3 . The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6 vol.% HA reinforced composite showed Ni 3 Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2 vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2 vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants. - Highlights: • NiTi-HA composites were synthesized using powder metallurgy route. • New phases such as NiTi 2 , Ni 3 Ti and Ni 4 Ti 3 were observed for sintered composites. • Mechanical properties enhanced with the increasing content of HA and new phases. • No martensitic transformation was observed for all composites by DSC analysis. • 2 vol.% HA composite is a novel candidate for biomedical implants.

Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant

Energy Technology Data Exchange (ETDEWEB)

Akmal, Muhammad, E-mail: muhammad.akmal@giki.edu.pk [Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640 (Pakistan); Raza, Ahmad, E-mail: ahmadrazac@yahoo.com [Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640 (Pakistan); Khan, Muhammad Mudasser; Khan, M. Imran [Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640 (Pakistan); Hussain, Muhammad Asif [Department of Chemical Engineering, Kangwon National University, Samcheok, 25913 (Korea, Republic of)

2016-11-01

Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6 vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10 h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3 h at 1325 K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi{sub 2}, Ni{sub 3}Ti, and Ni{sub 4}Ti{sub 3}. The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6 vol.% HA reinforced composite showed Ni{sub 3}Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2 vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2 vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants. - Highlights: • NiTi-HA composites were synthesized using powder metallurgy route. • New phases such as NiTi{sub 2}, Ni{sub 3}Ti and Ni{sub 4}Ti{sub 3} were observed for sintered composites. • Mechanical properties enhanced with the increasing content of HA and new phases. • No martensitic transformation was observed for all composites by DSC analysis. • 2 vol.% HA composite is a novel candidate for biomedical implants.

Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants.

Science.gov (United States)

Gryshkov, Oleksandr; Klyui, Nickolai I; Temchenko, Volodymyr P; Kyselov, Vitalii S; Chatterjee, Anamika; Belyaev, Alexander E; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

2016-11-01

Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO2) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. Copyright © 2016 Elsevier B.V. All rights reserved.

Innovative micro-textured hydroxyapatite and poly(l-lactic)-acid polymer composite film as a flexible, corrosion resistant, biocompatible, and bioactive coating for Mg implants.

Science.gov (United States)

Kim, Sae-Mi; Kang, Min-Ho; Kim, Hyoun-Ee; Lim, Ho-Kyung; Byun, Soo-Hwan; Lee, Jong-Ho; Lee, Sung-Mi

2017-12-01

The utility of a novel ceramic/polymer-composite coating with a micro-textured microstructure that would significantly enhance the functions of biodegradable Mg implants is demonstrated here. To accomplish this, bioactive hydroxyapatite (HA) micro-dots can be created by immersing a Mg implant with a micro-patterned photoresist surface in an aqueous solution containing calcium and phosphate ions. The HA micro-dots can then be surrounded by a flexible poly(l-lactic)-acid (PLLA) polymer using spin coating to form a HA/PLLA micro-textured coating layer. The HA/PLLA micro-textured coating layer showed an excellent corrosion resistance when it was immersed in a simulated body fluid (SBF) solution and good biocompatibility, which was assessed by in vitro cell tests. In addition, the HA/PLLA micro-textured coating layer had high deformation ability, where no apparent changes in the coating layer were observed even after a 5% elongation, which would be unobtainable using HA and PLLA coating layers; furthermore, this allowed the mechanically-strained Mg implant with the HA/PLLA micro-textured coating layer to preserve its excellent corrosion resistance and biocompatibility in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

Energy Technology Data Exchange (ETDEWEB)

Rojaee, Ramin, E-mail: raminrojaee@aim.com [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Fathi, Mohammadhossein [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Raeissi, Keyvan [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

2013-11-15

Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF{sub 2} conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

International Nuclear Information System (INIS)

Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

2013-01-01

Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF 2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

Science.gov (United States)

Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

2013-11-01

Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

Hydroxyapatite in total hip arthroplasty. Our experience with a plasma spray porous titanium alloy/hydroxyapatite double-coated cementless stem.

Science.gov (United States)

Castellini, Iacopo; Andreani, Lorenzo; Parchi, Paolo Domenico; Bonicoli, Enrico; Piolanti, Nicola; Risoli, Francesca; Lisanti, Michele

2016-01-01

Total hip arthroplasty could fail due to many factors and one of the most common is the aseptic loosening. In order to achieve an effective osseointegration and reduce risk of lossening, the use of cemented implant, contact porous bearing surface and organic coating were developed. Aim of this study was to evaluate clinical and radiological mid-term outcomes of a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem applied with "plasma spray" technique and to demonstrate the possibility to use this stem in different types of femoral canals. Between January 2008 and December 2012, 240 consecutive primary total hip arthroplasties (THAs) were performed using a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem. 182 patients were examined: 136 were females (74.7%) and 46 males (25.2%); average age was 72 years old (ranging from 26 to 92 years old). For each patient, Harris Hip Scores (HHS) and Womac Scores were collected. All X-ray images were analyzed in order to demonstrate stem survival rate and subsidence. Harris Hip Score was good or excellent in 85% of the cases (average 90%) and mean WOMAC score was 97.5 (ranging from 73.4 to 100). No cases of early/late infection or periprosthetic fracture were noticed, with an excellent implant survival rate (100%) in a mean period of 40 months (ranging from 24 and 84 months). 5 cases presented acute implant dislocation, 2 due to wrong cup positioning in a dysplastic acetabulum and 3 after ground level fall. Dorr classification of femoral geometry was uses and the results were: 51 type A bone, 53 type B bone and 78 type C bone. Stem subsidence over 2 mm was considered as a risk factor of future implant loosening and was evidenced in 3 female patients with type C of Dorr classification. No radiolucencies signs around the proximally coated portion of stem or proximal reabsorption were visible during the radiographic follow-up. Concerning the use of porous

Hydroxyapatite/poly(epsilon-caprolactone) double coating on magnesium for enhanced corrosion resistance and coating flexibility.

Science.gov (United States)

Jo, Ji-Hoon; Li, Yuanlong; Kim, Sae-Mi; Kim, Hyoun-Ee; Koh, Young-Hag

2013-11-01

Hydroxyapatite was deposited on pure magnesium (Mg) with a flexible poly(ε-caprolactone) interlayer to reduce the corrosion rate of Mg and enhance coating flexibility. The poly(ε-caprolactone) interlayer was uniformly coated on Mg by a spraying method, followed by hydroxyapatite deposition on the poly(ε-caprolactone) using an aerosol deposition method. In scanning electron microscopy observations, inorganic/organic composite-like structure was observed between the hydroxyapatite and poly(ε-caprolactone) layers, resulting from the collisions of hydroxyapatite particles into the poly(ε-caprolactone) matrix at the initial stage of the aerosol deposition. The corrosion resistance of the coated Mg was examined using potentiodynamic polarization tests. The hydroxyapatite/poly(ε-caprolactone) double coating remarkably improved the corrosion resistance of Mg in Hank's solution. In the in vitro cell tests, the coated Mg showed better cell adhesion compared with the bare Mg due to the reduced corrosion rate and enhanced biocompatibility. The stability and flexibility of hydroxyapatite/poly(ε-caprolactone) double coating was investigated by scanning electron microscopy inspections after the coated Mg was deformed. The hydroxyapatite coating on the poly(ε-caprolactone) interlayer revealed enhanced coating stability and flexibility without cracking or delamination during bending and stretching compared with the hydroxyapatite single coating. These results demonstrated that the hydroxyapatite/poly(ε-caprolactone) double coating significantly improved the surface corrosion resistance of Mg and enhanced coating flexibility for use of Mg as a biodegradable implant.

Surface modification of implants in long bone.

Science.gov (United States)

Förster, Yvonne; Rentsch, Claudia; Schneiders, Wolfgang; Bernhardt, Ricardo; Simon, Jan C; Worch, Hartmut; Rammelt, Stefan

2012-01-01

Coatings of orthopedic implants are investigated to improve the osteoinductive and osteoconductive properties of the implant surfaces and thus to enhance periimplant bone formation. By applying coatings that mimic the extracellular matrix a favorable environment for osteoblasts, osteoclasts and their progenitor cells is provided to promote early and strong fixation of implants. It is known that the early bone ongrowth increases primary implant fixation and reduces the risk of implant failure. This review presents an overview of coating titanium and hydroxyapatite implants with components of the extracellular matrix like collagen type I, chondroitin sulfate and RGD peptide in different small and large animal models. The influence of these components on cells, the inflammation process, new bone formation and bone/implant contact is summarized.

The possibilities of atmospheric plasma-spraying application to obtain hydroxyapatite coatings on the stainless steel samples

Directory of Open Access Journals (Sweden)

Mihailović Marija D.

2013-01-01

Full Text Available For decades, the standard metallic materials for hip implants, besides the 316LVM stainless steel, were titanium- and cobalt/chromium-based alloys. Although bioinert, due to their corrosion resistance, they are not biocompatible. Contemporary surgical implants are not made just of bioinert metal anymore, but with deposited bioactive hydroxyapatite (HAp coating. Hydroxyapatite is chemically identical with the mineral constituent of bones and teeth, what besides its biocompatibility provides bioactivity as well. The HAp limitations are, however, weak tensile strength and low fatigue resistance for long term loadings, if used alone. This is the reason for HAp to be deposited onto the surgical implant, and to enable its bioactivity, what means intergrowth with bones, and therefore the long-lasting and mechanical stable non-cemented prosthesis. This is important predominantly because the need for such prostheses for younger population, and a better life quality. There are several contemporary techniques that have been used for deposition of these coatings onto the metal implant. The possibilities of atmospheric plasma-spraying for obtaining the stable HAp coatings on the 316LVM stainless steel, ordinary used as a standard material for hip implants production are presented in this paper. The coatings of a commercially available hydroxyapatite powder were plasma-sprayed onto the specimens of medical grade 316LVM stainless steel under various operating conditions. The optical microscopy was used for microstructure and porosity characterization, while coating morphology and Ca/P ratio were analyzed using SEM equipped with EDX. Coating microstructure varied from a porous to a glassy structure, depending on operating conditions applied and coating thickness. Coating porosity was determined to be at the lower required limit requested for the bone-coating intergrowth possibility, but nevertheless adhesion measurements showed good results. The Ca/P ratio was

Synthesis and Characterization of Nano-Hydroxyapatite/mPEG-b-PCL Composite Coating on Nitinol Alloy

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Mohamadreza Etminanfar

2017-12-01

Full Text Available In this study the bioactivity of hydroxyapatite/poly(ε-caprolactone–poly(ethylene glycol bilayer coatings on Nitinol superelastic alloy was investigated. The surface of Nitinol alloy was activated by a thermo-chemical treatment and hydroxyapatite coating was electrodeposited on the alloy, followed by applying the polymer coating. The surface morphology of coatings was studied using FE-SEM and SEM. The data revealed that the hydroxyapatite coating is composed of one-dimensional nano sized flakes and the polymer coating is uniformly covered the sublayer. Also, High resolution TEM studies on the hydroxyapatite samples revealed that each flake contains nano-crystalline grains with a diameter of about 15 nm. The hydroxyapatite monolayer coating was rapidly covered by calcium phosphate crystals (Ca/P=1.7 after immersion in simulated body fluid confirming the bioactivity of the nanostructured flakes. However, the flakes were weak against applied external forces because of their ultra-fine thickness. Scratch test was applied on hydroxyapatite/polymer coating to evaluate delamination of the coating from substrate. It was shown that, the polymer coating has a great influence on toughening the hydroxyapatite coating. To assess the degradation effect of the polymer layer on hydroxyapatite coating, samples were immersed in phosphate-buffered saline at 37 ᵒC. SEM studies on the samples revealed that the beneath layer of hydroxyapatite appears after 72 h without any visible change in morphology. It seems that, application of a biodegradable polymer film on the nanostructured hydroxyapatite coating is a good way to support the coating during implantation processes

Implante intra-ocular de lentes dobráveis "piggyback" em paciente portador de catarata congênita no primeiro ano de vida: relato de caso Piggyback foldable intraocular lens implant in patient with congenital cataract in the first year of life: case report

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Leonardo Akaishi

2004-12-01

Full Text Available No presente relato os autores descrevem um caso de catarata congênita unilateral tratada cirurgicamente com implante intra-ocular de lentes dobráveis "piggyback", ainda não descrito na literatura nacional. São analisadas as diferenças e semelhanças com outros casos descritos na literatura.The authors report a case of congenital cataract, which was treated with piggyback foldable intraocular lens implant, not described in the Brazilian literature. The differences and similarities are analyzed with other reported cases in the literature.

Biogenic Hydroxyapatite: A New Material for the Preservation and Restoration of the Built Environment.

Science.gov (United States)

Turner, Ronald J; Renshaw, Joanna C; Hamilton, Andrea

2017-09-20

Ordinary Portland cement (OPC) is by weight the world's most produced man-made material and is used in a variety of applications in environments ranging from buildings, to nuclear wasteforms, and within the human body. In this paper, we present for the first time the direct deposition of biogenic hydroxyapatite onto the surface of OPC in a synergistic process which uses the composition of the cement substrate. This hydroxyapatite is very similar to that found in nature, having a similar crystallite size, iron and carbonate substitution, and a semi-crystalline structure. Hydroxyapatites with such a structure are known to be mechanically stronger and more biocompatible than synthetic or biomimetic hydroxyapatites. The formation of this biogenic hydroxyapatite coating therefore has significance in a range of contexts. In medicine, hydroxyapatite coatings are linked to improved biocompatibility of ceramic implant materials. In the built environment, hydroxyapatite coatings have been proposed for the consolidation and protection of sculptural materials such as marble and limestone, with biogenic hydroxyapatites having reduced solubility compared to synthetic apatites. Hydroxyapatites have also been established as effective for the adsorption and remediation of environmental contaminants such as radionuclides and heavy metals. We identify that in addition to providing a biofilm scaffold for nucleation, the metabolic activity of Pseudomonas fluorescens increases the pH of the growth medium to a suitable level for hydroxyapatite formation. The generated ammonia reacts with phosphate in the growth medium, producing ammonium phosphates which are a precursor to the formation of hydroxyapatite under conditions of ambient temperature and pressure. Subsequently, this biogenic deposition process takes place in a simple reaction system under mild chemical conditions and is cheap and easy to apply to fragile biological or architectural surfaces.

Synthesis and characterization of hydroxyapatite-gelatine composite materials for orthopaedic application

International Nuclear Information System (INIS)

Yanovska, A.; Kuznetsov, V.; Stanislavov, A.; Husak, E.; Pogorielov, M.; Starikov, V.; Bolshanina, S.; Danilchenko, S.

2016-01-01

The composite materials based on hydroxyapatite (HA) and gelatine (Gel) with addition of silver and zirconium oxide were obtained. The study investigates a combination of low powered ultrasonic irradiation and low concentration of gelatine in the co-precipitation synthesis. These composites have different weight ratios of organic/inorganic components and may be synthesized in two ways: simple mixing and co-precipitation. Both of which were compared. The estimation of porosity, in vivo testing, surface morphology and phase composition as well as the IR-analysis were provided. Hydroxyapatite was the main crystalline phase in obtained composites. While around powdered HA-Gel composite the connective tissue capsule is formed without bone tissue formation, HA-Gel-Ag porous composite implantation leads to formation of new bone tissue and activation of cell proliferation. Addition of silver ions into composite material allows decreasing inflammation on the first stage of implantation and has positive effect on bone tissue formation. Some of the obtained composite materials containing silver or ZrO_2 are biocompatible. bio-resorbable and osteoconductive with high level of porosity (75–85%). - Highlights: • Hydroxyapatite-gelatine composites with addition of Ag"+ and ZrO_2 were obtained. • Composites were synthesized in two ways: simple mixing and co-precipitation. • Co-precipitation synthesis combined ultrasonic treatment and low concentration of gelatine. • Obtained composites have different weight ratios of organic/inorganic components. • Some composites are osteoconductive and all of them have high level of porosity (75–85%).

Osteogenic protein-1 increases the fixation of implants grafted with morcellised bone allograft and ProOsteon bone substitute: an experimental study in dogs

DEFF Research Database (Denmark)

Jensen, T B; Overgaard, S; Lind, M

2007-01-01

Impacted bone allograft is often used in revision joint replacement. Hydroxyapatite granules have been suggested as a substitute or to enhance morcellised bone allograft. We hypothesised that adding osteogenic protein-1 to a composite of bone allograft and non-resorbable hydroxyapatite granules...... (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant...... surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three...

Effects of sodium hyaluronate on ocular inflammatory response and dry eye after phacoemulsification combined with IOL implantation for cataract

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Xing-Guang He

2018-04-01

Full Text Available AIM: To investigate the effect of sodium hyaluronate eye drops on ocular inflammatory response and dry eye after phacoemulsification combined with intraocular lenses(IOLimplantation for age-related cataract. METHODS: The clinical data of age-related cataract patients treated with phacoemulsification combined with IOL implantation in 200 cases(200 eyesof our hospital from June 2016 to July 2017 were retrospectively analyzed. According to the different postoperative application of eye drops they were divided into observation group and control group(100 cases each. The observation group was given sodium hyaluronate eye drops and the control group was given tobramycin dexamethasone eye drops. The results of BUT, FL, proteins concentration in aqueous and ocular surface disease index(OSDIscore were compared before and at the first day, the seventh day and the fourteenth day after the operation. And the incidence of conjunctival hyperemia and ciliary hyperemia was compared between 1d after surgery and 14d after surgery. RESULTS: There was no significant difference in OSDI scores between the two groups before and at 1d after surgery(P>0.05. The OSDI score of the two groups was higher than that before the operation on the first, the seventh and the fourteenth day after surgery(PPPP>0.05. The levels of BUT in the two groups were lower than those before operation on the first, the seventh and the fourteenth day after surgery(PPPP>0.05. The levels of FL in the two groups were different from those before operation(PPPPP>0.05; the incidence of conjunctival hyperemia and ciliary hyperemia in the two groups on the fourteenth day after surgery was lower than that on the first day after surgery(PPPPPCONCLUSION: The effect of sodium hyaluronate eye drops on improving dry eye after age-related cataract phacoemulsification combined with IOL implantation is greater than that of tobramycin dexamethasone eye drops, but it is less effective for eye inflammation than

Stiffness compatibility of coralline hydroxyapatite bone substitute under dynamic loading

Institute of Scientific and Technical Information of China (English)

REN ChaoFeng; HOU ZhenDe; ZHAO Wei

2009-01-01

When hydroxyapatite bone substitutes are implanted in human bodies, bone tissues will grow into their porous structure, which will reinforce their strength and stiffness. The concept of mechanical com-patibility of bone substitutes implies that their mechanical properties are similar to the bone tissues around, as if they were part of the bone. The mechanical compatibility of bone substitutes includes both static and dynamic behavior, due to the mechanical properties of bone depending on the strain rate. In this study, split Hopkinson pressure bar technique (SHPB) was employed to determine the dy-namic mechanical properties of coralline hydroxyapatite, bones with and bones without organic com-ponents, and their dynamic stress-strain curves of the three materials were obtained. The mechanical effects of collagens in bone were assessed, by comparing the difference between the Young's moduli of the three materials. As the implanted bone substitute becomes a part of bone, it can be regarded as an inclusion composite. The effective modulus of the composite was also evaluated in order to estimate its mechanical compatibility on stiffness. The evaluated result shows that the suitable porosity of HA is0.8, which is in favor of both static and dynamic stiffness compatibility.

CAD-CAM-generated hydroxyapatite scaffold to replace the mandibular condyle in sheep: preliminary results.

Science.gov (United States)

Ciocca, Leonardo; Donati, Davide; Fantini, Massimiliano; Landi, Elena; Piattelli, Adriano; Iezzi, Giovanna; Tampieri, Anna; Spadari, Alessandro; Romagnoli, Noemi; Scotti, Roberto

2013-08-01

In this study, rapid CAD-CAM prototyping of pure hydroxyapatite to replace temporomandibular joint condyles was tested in sheep. Three adult animals were implanted with CAD-CAM-designed porous hydroxyapatite scaffolds as condyle substitutes. The desired scaffold shape was achieved by subtractive automated milling machining (block reduction). Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Using the same technique, fixation plates were created and applied to the scaffold pre-operatively to firmly secure the condyles to the bone and to assure primary stability of the hydroxyapatite scaffolds during masticatory function. Four months post-surgery, the sheep were sacrificed. The hydroxyapatite scaffolds were explanted, and histological specimens were prepared. Different histological tissues penetrating the scaffold macropores, the sequence of bone remodeling, new apposition of bone and/or cartilage as a consequence of the different functional anatomic role, and osseointegration at the interface between the scaffold and bone were documented. This animal model was found to be appropriate for testing CAD-CAM customization and the biomechanical properties of porous, pure hydroxyapatite scaffolds used as joint prostheses.

Intra-ocular lens implantation after vitreous loss.

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Shah N

1991-10-01

Full Text Available Vitreous loss is a dreaded complication of cataract surgery, especially so with IOL implant which then may have to be abandoned. Thirty three cases of IOL implants, either anterior chamber or posterior chamber, after vitreous loss done in the past 3 years were studied. Of these, 18 (55% had a final visual acuity of 6/18 or better and none was worse than 6/60. The postoperative complications and findings and a review of literature are discussed.

[Apatite-forming ability of pure titanium implant after micro-arc oxidation treatment].

Science.gov (United States)

Tian, Zhihui; Zhang, Yu; Wang, Lichao; Nan, Kaihui

2013-10-01

To investigate the apatite forming ability of pure titanium implant after micro-arc oxidation treatment in simulated body fluid (SBF) and obtain implants with calcium phosphate (Ca-P) layers. The implants were immersed in (SBF) after micro-arc oxidation treatment for different time lengths, and their apatite forming ability and the morphology and constituents of the Ca-P layers formed on the sample surface were analyzed using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive electron probe. After immersion in SBF, large quantities of Ca-P layers were induced on the surface of the samples. The Ca-P layers were composed of octacalcium phosphate and carbonated hydroxyapatite, and the crystals showed a plate-like morphology with an oriented growth. The implants with micro-arc oxidation treatment show good apatite forming ability on the surface with rich calcium and phosphorus elements. The formed layers are composed of bone-like apatite including octacalcium phosphate and carbonated hydroxyapatite.

Recent Advances in Ocular Drug Delivery Systems

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Shinobu Fujii

2011-01-01

Full Text Available Transport of drugs applied by traditional dosage forms is restricted to the eye, and therapeutic drug concentrations in the target tissues are not maintained for a long duration since the eyes are protected by a unique anatomy and physiology. For the treatment of the anterior segment of the eye, various droppable products to prolong the retention time on the ocular surface have been introduced in the market. On the other hand, direct intravitreal implants, using biodegradable or non-biodegradable polymer technology, have been widely investigated for the treatment of chronic vitreoretinal diseases. There is urgent need to develop ocular drug delivery systems which provide controlled release for the treatment of chronic diseases, and increase patient’s and doctor’s convenience to reduce the dosing frequency and invasive treatment. In this article, progress of ocular drug delivery systems under clinical trials and in late experimental stage is reviewed.

Current status of grafts and implants in rhinoplasty: Part II. Homologous grafts and allogenic implants.

Science.gov (United States)

Sajjadian, Ali; Naghshineh, Nima; Rubinstein, Roee

2010-03-01

After reading this article, the participant should be able to: 1. Understand the challenges in restoring volume and structural integrity in rhinoplasty. 2. Identify the appropriate uses of various homologous grafts and allogenic implants in reconstruction, including: (a) freeze-dried acellular allogenic cadaveric dermis grafts, (b) irradiated cartilage grafts, (c) hydroxyapatite mineral matrix, (d) silicone implants, (e) high-density polyethylene implants, (f) polytetrafluoroethylene implants, and (g) injectable filler materials. 3. Identify the advantages and disadvantages of each of these biomaterials. 4. Understand the specific techniques that may aid in the use these grafts or implants. This review specifically addresses the use of homologous grafts and allogenic implants in rhinoplasty. It is important to stress that autologous materials remain the preferred graft material for use in rhinoplasty, owing to their high biocompatibility and low risk of infection and extrusion. However, concerns of donor-site morbidity, graft availability, and graft resorption have motivated the development and use of homologous and allogenic implants.

Novel selenium-doped hydroxyapatite coatings for biomedical applications.

Science.gov (United States)

Rodríguez-Valencia, C; López-Álvarez, M; Cochón-Cores, B; Pereiro, I; Serra, J; González, P

2013-03-01

Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. Copyright © 2012 Wiley Periodicals, Inc.

Ocular Toxicity after High-Dose Cefuroxime Injection into the Anterior Chamber

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Harun Çakmak

2016-08-01

Full Text Available Cephalosporins are beta-lactam antibiotics and, like penicillin derivatives, they show bacteriostatic effect by disrupting bacterial cell wall synthesis. Cefuroxime is a second generation cephalosporin and the use of intracameral cefuroxime after cataract surgery has been widely used in the endophthalmitis prophylaxis. A 78-year-old male patient was operated for cataracts in both eyes about 8 years ago. Ocular trauma has occurred in the left eye nine months ago. Vitrectomy surgery combined with intraocular lens extraction was performed and the patient was left aphakic. Secondary intraocular lens implantation was performed. In this paper, we present postoperative ocular findings in a patient who was given cefuroxime into the anterior chamber 2.5 times higher than the recommended dose (25 mg/ml after secondary intraocular lens implantation.

Adhesion of composite carbon/hydroxyapatite coatings on AISI 316L medical steel

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J. Gawroński

2009-07-01

Full Text Available In this paper are contains the results of studies concerning the problems associated with increased of hydroxyapatite (HAp adhesion, manufactured by using Pulse Laser Deposition (PLD method, to the austenitic steel (AISI 316L through the coating of carbon interlayer on it. Carbon coating was deposited by Radio Frequency Plasma Assisted Chemical Vapour Deposition (RF PACVD method.Test results unequivocally showed that the intermediate carbon layer in a determined manner increase the adhesion of hydroxyapatite to the metallic substrate. Obtained results give rise to deal with issues of manufacturing composite bilayer – carbon film/HAp – on ready implants, casted from austenitic cast steel by lost-wax process method as well as in gypsum forms.

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

Energy Technology Data Exchange (ETDEWEB)

Hahn, Byung-Dong, E-mail: cera72@kims.re.kr [Functional Ceramics Group, Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeong-Nam, 641-010 (Korea, Republic of); Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo [Functional Ceramics Group, Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeong-Nam, 641-010 (Korea, Republic of); Kim, Hyoun-Ee [School of Materials Science and Engineering, Seoul National University, San 56-1 Sillim-Dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Yoon, Byung-Ho; Jung, In-Kwon [GENOSS, Gyeonggi R and DB Center, Iui-dong, Yeongtong-gu, Suwon, Gyeonggi-do, 443-270 (Korea, Republic of)

2013-10-15

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

International Nuclear Information System (INIS)

Hahn, Byung-Dong; Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo; Kim, Hyoun-Ee; Yoon, Byung-Ho; Jung, In-Kwon

2013-01-01

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Osteoconductive hydroxyapatite coated PEEK for spinal fusion surgery

Science.gov (United States)

Hahn, Byung-Dong; Park, Dong-Soo; Choi, Jong-Jin; Ryu, Jungho; Yoon, Woon-Ha; Choi, Joon-Hwan; Kim, Jong-Woo; Ahn, Cheol-Woo; Kim, Hyoun-Ee; Yoon, Byung-Ho; Jung, In-Kwon

2013-10-01

Polyetheretherketone (PEEK) has attracted much interest as biomaterial for interbody fusion cages due to its similar stiffness to bone and good radio-transparency for post-op visualization. Hydroxyapatite (HA) coating stimulates bone growth to the medical implant. The objective of this work is to make an implant consisting of biocompatible PEEK with an osteoconductive HA surface for spinal or orthopedic applications. Highly dense and well-adhered HA coating was developed on medical-grade PEEK using aerosol deposition (AD) without thermal degradation of the PEEK. The HA coating had a dense microstructure with no cracks or pores, and showed good adhesion to PEEK at adhesion strengths above 14.3 MPa. The crystallinity of the HA coating was remarkably enhanced by hydrothermal annealing as post-deposition heat-treatment. In addition, in vitro and in vivo biocompatibility of PEEK, in terms of cell adhesion morphology, cell proliferation, differentiation, and bone-to-implant contact ratio, were remarkably enhanced by the HA coating through AD.

Coralline hydroxyapatite: a bone graft alternative in foot and ankle surgery.

Science.gov (United States)

Rahimi, F; Maurer, B T; Enzweiler, M G

1997-01-01

The use of coralline hydroxyapatite has become a viable bone grafting alternative. Its efficacy has been well established through multiple human and animal studies. Coralline hydroxyapatite enhances osteogenesis by providing a biocompatible lattice for the passage and assembly of vascular, fibroblastic, and osteoblastic tissues. It also provides support for surrounding osseous structures. The uses of this material are expanding into the realm of foot and ankle surgery. Its consideration as an appropriate bone graft substitute as well as multiple case studies demonstrating its surgical applicability are discussed. The implants utilized at Thorek Hospital and Medical Center over the past eight years, with an average follow-up of three and one-half years, have proven to be a valuable resource for augmentation where an osseous defect has occurred.

Suspension thermal spraying of hydroxyapatite: Microstructure and in vitro behaviour

Energy Technology Data Exchange (ETDEWEB)

Bolelli, Giovanni, E-mail: giovanni.bolelli@unimore.it [Department of Engineering “Enzo Ferrari”, Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena, MO (Italy); Bellucci, Devis; Cannillo, Valeria; Lusvarghi, Luca; Sola, Antonella [Department of Engineering “Enzo Ferrari”, Università di Modena e Reggio Emilia, Via Vignolese 905, 41125 Modena, MO (Italy); Stiegler, Nico; Müller, Philipp; Killinger, Andreas; Gadow, Rainer [Institute for Manufacturing Technologies of Ceramic Components and Composites (IMTCCC), Universität Stuttgart, Allmandring 7b, 70569 Stuttgart (Germany); Altomare, Lina; De Nardo, Luigi [Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano (Italy)

2014-01-01

In cementless fixation of metallic prostheses, bony ingrowth onto the implant surface is often promoted by osteoconductive plasma-sprayed hydroxyapatite coatings. The present work explores the use of the innovative High Velocity Suspension Flame Spraying (HVSFS) process to coat Ti substrates with thin homogeneous hydroxyapatite coatings. The HVSFS hydroxyapatite coatings studied were dense, 27–37 μm thick, with some transverse microcracks. Lamellae were sintered together and nearly unidentifiable, unlike conventional plasma-sprayed hydroxyapatite. Crystallinities of 10%–70% were obtained, depending on the deposition parameters and the use of a TiO{sub 2} bond coat. The average hardness of layers with low (< 24%) and high (70%) crystallinity was ≈ 3.5 GPa and ≈ 4.5 GPa respectively. The distributions of hardness values, all characterised by Weibull modulus in the 5–7 range, were narrower than that of conventional plasma-sprayed hydroxyapatite, with a Weibull modulus of ≈ 3.3. During soaking in simulated body fluid, glassy coatings were progressively resorbed and replaced by a new, precipitated hydroxyapatite layer, whereas coatings with 70% crystallinity were stable up to 14 days of immersion. The interpretation of the precipitation behaviour was also assisted by surface charge assessments, performed through Z-potential measurements. During in vitro tests, HA coatings showed no cytotoxicity towards the SAOS-2 osteoblast cell line, and surface cell proliferation was comparable with proliferation on reference polystyrene culture plates. - Highlights: • Thin, dense HA layers were originated by HVSFS deposition of molten agglomerates of ≈ 1 μm. • Tensile adhesion strength of HVSFS HA onto Ti well above the threshold of ISO 13779-2 • Crystallinity (10–70%) is determined by system temperature during deposition. • Crystallinity controls the reactivity during immersion in simulated body fluid. • SAOS-2 osteoblast-like cells adhered well and

Characterisation of a new alkoxide sol-gel hydroxyapatite

International Nuclear Information System (INIS)

Green, D.D.; Kannangara, G.S.K.; Milev, A.; Ben-Nissan, B.

1999-01-01

Hydroxyapatite (HAp) coatings have been used to promote bone growth and fixation towards implant surfaces to encourage faster recovery times for the recipient. Current coating processing techniques, capable of producing thin HAp layers are pulsed-laser deposition and sputtering (high-temperature processing). Other technologies are in vitro methods, electrodeposition and sol-gel, due to the fact that these techniques utilise lower processing temperatures they avoid structural instabilities of HAp at elevated temperatures. The term sol-gel encompasses any process of producing ceramic materials (single and mixed oxides, as well as non-oxides e.g. nitrides) from solutions. The sol-gel process was first identified by Ebelman, and has been used to produce ceramic powders, coatings, and bulk materials including glasses. The implementation of a sol-gel methodology enables increased stoichiometry and homogeneity, while having the ability to coat complex shapes. Sol-gel hydroxyapatite reported by Chai et al. employed tri ethyl phosphite [ P(OEt) 3 ] as the staring phosphorus alkoxide precursor, whereby it was established that in order to obtain monophasic hydroxyapatite upon firing there must be a 24 hour ripening period. The ripening period was determined to be an equilibrium step whereby the equilibrium intermediate phase lied in favour of a diethyl phosphite arrangement (species) within the sol. Therefore, the work here under taken was to produce hydroxyapatite using diethyl phosphite [HOP(OEt) 2 ] as a starting alkoxide precursor with a final aim to reduce or eliminate the ageing period as observed by Chai et al in P(OEt) 3 solutions

Synthesis and characterization of hydroxyapatite-gelatine composite materials for orthopaedic application

Energy Technology Data Exchange (ETDEWEB)

Yanovska, A., E-mail: biophy@yandex.ru [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Kuznetsov, V. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Stanislavov, A. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Husak, E. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine); Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Pogorielov, M. [Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Starikov, V. [National Technical University ”Kharkov Polytechnic Institute”, 21 Frunze Str., 61002, Kharkov (Ukraine); Bolshanina, S. [Sumy State University, Ministry of Education and Science of Ukraine, 2 R. Korsakova Str., 40007, Sumy (Ukraine); Danilchenko, S. [Institute of Applied Physics, National Academy of Sciences of Ukraine, 58 Petropavlovskaya Str., 40000, Sumy (Ukraine)

2016-11-01

The composite materials based on hydroxyapatite (HA) and gelatine (Gel) with addition of silver and zirconium oxide were obtained. The study investigates a combination of low powered ultrasonic irradiation and low concentration of gelatine in the co-precipitation synthesis. These composites have different weight ratios of organic/inorganic components and may be synthesized in two ways: simple mixing and co-precipitation. Both of which were compared. The estimation of porosity, in vivo testing, surface morphology and phase composition as well as the IR-analysis were provided. Hydroxyapatite was the main crystalline phase in obtained composites. While around powdered HA-Gel composite the connective tissue capsule is formed without bone tissue formation, HA-Gel-Ag porous composite implantation leads to formation of new bone tissue and activation of cell proliferation. Addition of silver ions into composite material allows decreasing inflammation on the first stage of implantation and has positive effect on bone tissue formation. Some of the obtained composite materials containing silver or ZrO{sub 2} are biocompatible. bio-resorbable and osteoconductive with high level of porosity (75–85%). - Highlights: • Hydroxyapatite-gelatine composites with addition of Ag{sup +} and ZrO{sub 2} were obtained. • Composites were synthesized in two ways: simple mixing and co-precipitation. • Co-precipitation synthesis combined ultrasonic treatment and low concentration of gelatine. • Obtained composites have different weight ratios of organic/inorganic components. • Some composites are osteoconductive and all of them have high level of porosity (75–85%).

Coating of the orthopaedic titanium alloys with sol-gel derived hydroxyapatite

International Nuclear Information System (INIS)

Milev, A.; Green, D.; Chai, C.S.; Ben-Nissan, B.

1999-01-01

Hydroxyapatite (HAp) is known to be both biocompatible and bioactive material, however, due to its poor mechanical properties and design limitations is not suitable for applying as a load bearing implant. This could be overcome by using appropriate metallic substrates covered with HAp, derived via different techniques. These coatings allow improved adhesion strength of the load bearing substrate to the bone, resulting in shorter healing periods as well as predictable behaviour of the implant for longer periods of time. There are different techniques of producing HAp appropriate for coating purposes. Due to the small particle size of the grains derived, sol-gel route is preferable where lower sintering temperatures are of primary importance. For better adhesion between substrate and hydroxyapatite coating, the surface of titanium substrate, in this study, was converted to titanium nitride and/or oxynitride. Sintering temperatures of 900 deg C have been used for producing crystalline HAp coatings. The control of sol-gel solutions and the analysis of the coatings were carried out using XRD, SEM and DTA techniques. Results obtained indicate high quality HAp coatings can be produced on titanium substrates especially with complex shapes that benefits over the other coating methods

Nanoscale hydroxyapatite particles for bone tissue engineering.

Science.gov (United States)

Zhou, Hongjian; Lee, Jaebeom

2011-07-01

Hydroxyapatite (HAp) exhibits excellent biocompatibility with soft tissues such as skin, muscle and gums, making it an ideal candidate for orthopedic and dental implants or components of implants. Synthetic HAp has been widely used in repair of hard tissues, and common uses include bone repair, bone augmentation, as well as coating of implants or acting as fillers in bone or teeth. However, the low mechanical strength of normal HAp ceramics generally restricts its use to low load-bearing applications. Recent advancements in nanoscience and nanotechnology have reignited investigation of nanoscale HAp formation in order to clearly define the small-scale properties of HAp. It has been suggested that nano-HAp may be an ideal biomaterial due to its good biocompatibility and bone integration ability. HAp biomedical material development has benefited significantly from advancements in nanotechnology. This feature article looks afresh at nano-HAp particles, highlighting the importance of size, crystal morphology control, and composites with other inorganic particles for biomedical material development. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Properties and in vivo investigation of nanocrystalline hydroxyapatite obtained by mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Silva, C.C.; Pinheiro, A.G.; Oliveira, R.S. de; Goes, J.C.; Aranha, N.; Oliveira, L.R. de; Sombra, A.S.B

2004-06-01

Mechanical alloying has been used successfully to produce nanocrystalline powders of hydroxyapatite (HA) using three different procedures. The milled HA was studied by X-ray diffraction, Infrared, Raman scattering spectroscopy and Scanning Electron Microscopy (SEM). We obtained HA with different degrees of crystallinity and time of milling. The grain size analysis through SEM and XRD shows particles with dimensions of 36.9, 14.3 and 35.5 nm (for (R1), (R2) and (R3), respectively) forming bigger units with dimensions given by 117.2, 110.8 and 154.4 nm (for (R1), (R2) and (R3), respectively). The Energy-Dispersive Spectroscopy (EDS) analysis showed that an atomic ratio of Ca/P=1.67, 1.83 and 1.50 for reactions (R1), (R2) and (R3), respectively. These results suggest that the R1 nanocrystalline ceramic is closer to the expected value for the ratio Ca/P for hydroxyapatite, which is 5/3 congruent with 1.67. The bioactivity analysis shows that all the samples implanted into the rabbits can be considered biocompatible, since they had been considered not toxic, had not caused inflammation and reject on the part of the organisms of the animals, during the period of implantation. The samples implanted in rabbits had presented new osseous tissue formation with the presence of osteoblasts cells.

Properties and in vivo investigation of nanocrystalline hydroxyapatite obtained by mechanical alloying

International Nuclear Information System (INIS)

Silva, C.C.; Pinheiro, A.G.; Oliveira, R.S. de; Goes, J.C.; Aranha, N.; Oliveira, L.R. de; Sombra, A.S.B.

2004-01-01

Mechanical alloying has been used successfully to produce nanocrystalline powders of hydroxyapatite (HA) using three different procedures. The milled HA was studied by X-ray diffraction, Infrared, Raman scattering spectroscopy and Scanning Electron Microscopy (SEM). We obtained HA with different degrees of crystallinity and time of milling. The grain size analysis through SEM and XRD shows particles with dimensions of 36.9, 14.3 and 35.5 nm (for (R1), (R2) and (R3), respectively) forming bigger units with dimensions given by 117.2, 110.8 and 154.4 nm (for (R1), (R2) and (R3), respectively). The Energy-Dispersive Spectroscopy (EDS) analysis showed that an atomic ratio of Ca/P=1.67, 1.83 and 1.50 for reactions (R1), (R2) and (R3), respectively. These results suggest that the R1 nanocrystalline ceramic is closer to the expected value for the ratio Ca/P for hydroxyapatite, which is 5/3 congruent with 1.67. The bioactivity analysis shows that all the samples implanted into the rabbits can be considered biocompatible, since they had been considered not toxic, had not caused inflammation and reject on the part of the organisms of the animals, during the period of implantation. The samples implanted in rabbits had presented new osseous tissue formation with the presence of osteoblasts cells

Difference in ocular surface temperature by infrared thermography in phakic and pseudophakic patients

Directory of Open Access Journals (Sweden)

Sniegowski M

2015-03-01

Full Text Available Matthew Sniegowski, Michael Erlanger, Raul Velez-Montoya, Jeffrey L Olson Ophthalmology Department, University of Colorado School of Medicine, Rocky Mountain Lions Eye Institute, Aurora, CO, USA Purpose: To assess the change in ocular surface temperature between healthy phakic and pseudophakic patients.Methods: We included patients with no history of ocular disease other than cataract. Patients were divided into three groups: clear lens, cataract, and pseudophakic. All patients had two ocular surface digital thermal scans. An average of five surface points was used as the mean ocular surface temperature. Results were analyzed with a one-way analysis of variance and a Tukey’s least significance difference test. The patients were further divided into phakic and pseudophakic groups. Correlation coefficients between several variables were done in order to assess dependencies.Results: Fifty-six eyes (28 cataracts, 12 clear lenses, 16 pseudophakic were enrolled. The mean ocular surface temperature in the cataract group was 34.14°C±1.51°C; clear lens: 34.43°C±2.27°C; and pseudophakic: 34.97°C±1.57°C. There were no statistical differences among the study groups (P=0.3. There was a nonsignificant negative correlation trend between age and surface temperature in the phakic group. The trend inverted in the pseudophakic group but without statistical significance.Conclusion: Although cataract extraction and intraocular lens implantation seem to induce a mild increase in ocular surface temperature, the effect is not clear and not significant. Keywords: digital thermal scans, intraocular lens implantation, cataract extraction

Carbonate hydroxyapatite and silicon-substituted carbonate hydroxyapatite

DEFF Research Database (Denmark)

Bang, L T; Long, B D; Othman, R

2014-01-01

The present study investigates the chemical composition, solubility, and physical and mechanical properties of carbonate hydroxyapatite (CO3Ap) and silicon-substituted carbonate hydroxyapatite (Si-CO3Ap) which have been prepared by a simple precipitation method. X-ray diffraction (XRD), Fourier......(3-)) site and also entered simultaneously into the hydroxyapatite structure. The Si-substituted CO3Ap reduced the powder crystallinity and promoted ion release which resulted in a better solubility compared to that of Si-free CO3Ap. The mean particle size of Si-CO3Ap was much finer than that of CO3Ap...

Microwave annealing for preparation of crystalline hydroxyapatite thin films

CSIR Research Space (South Africa)

Adams, D

2006-11-01

Full Text Available Hydroxyapatite (HA) is widely preferred as the bio- material coating of choice in both dental and ortho- paedic implants due to its favourable osteo-conductive and bioactive properties [1]. Sol–gel synthesis of HA offers a viable alternative to the high... viable option because it is performed in air. Microwave heating differs fundamentally from conventional heating in that heat energy is generated from within the material instead of originating from D. Adams (&) Department of Physics, University...

Coating of Bio-mimetic Minerals-Substituted Hydroxyapatite on Surgical Grade Stainless Steel 316L by Electrophoretic Deposition for Hard tissue Applications

Science.gov (United States)

Govindaraj, Dharman; Rajan, Mariappan

2018-02-01

Third-era bio-implant materials intend to empower particular live cell reactions at the atomic level, these materials represented with a resorbable and biocompatibility that bodies recuperate once they have been embedded. Necessitate to decrease expenses in public health services has required the utilization of surgical grade stainless steel (SS 316L) as the most inexpensive choice for orthodontic and orthopaedic implants. 316L SS is one of the broadly used implant biomaterials in orthodontic and orthopaedic surgeries. Yet, frequently those discharge for toxic metal ions is confirm from the implants and hence a second surgery is required will remove those implant material. One approach to managing the discharge of toxic metal ions is to coat the implant substance with bio-mimetic minerals in hydroxyapatite (HA). Bio-mimetic minerals such as magnesium (Mg), strontium (Sr), also zinc (Zn) were revealed with animate bone growth furthermore restrain bone resorption both in vitro and in vivo. The present work deals with the electrophoretic deposition (EPD) for multi minerals substituted hydroxyapatite (M-HA) on the surface treated 316L SS under distinctive temperatures (27°C, (room temperature), 60 and 80°C). The resultant coatings were characterized by FT-IR, XRD, SEM-EDX, adhesion strength and leach out analysis.

Stiffness compatibility of coralline hydroxyapatite bone substitute under dynamic loading

Institute of Scientific and Technical Information of China (English)

无

2009-01-01

When hydroxyapatite bone substitutes are implanted in human bodies,bone tissues will grow into their porous structure,which will reinforce their strength and stiffness.The concept of mechanical com-patibility of bone substitutes implies that their mechanical properties are similar to the bone tissues around,as if they were part of the bone.The mechanical compatibility of bone substitutes includes both static and dynamic behavior,due to the mechanical properties of bone depending on the strain rate.In this study,split Hopkinson pressure bar technique(SHPB) was employed to determine the dy-namic mechanical properties of coralline hydroxyapatite,bones with and bones without organic com-ponents,and their dynamic stress-strain curves of the three materials were obtained.The mechanical effects of collagens in bone were assessed,by comparing the difference between the Young’s moduli of the three materials.As the implanted bone substitute becomes a part of bone,it can be regarded as an inclusion composite.The effective modulus of the composite was also evaluated in order to estimate its mechanical compatibility on stiffness.The evaluated result shows that the suitable porosity of HA is 0.8,which is in favor of both static and dynamic stiffness compatibility.

Study of wettability and cell viability of H implanted stainless steel

Science.gov (United States)

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.

Oriented hydroxyapatite single crystals produced by the electrodeposition method

Energy Technology Data Exchange (ETDEWEB)

Santos, E.A. dos, E-mail: euler@ufs.br [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Moldovan, M.S. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Jacomine, L. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France); Mateescu, M. [IS2M - Equipe Interaction Surface-Matiere Vivant, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Werckmann, J. [IPCMS - Departement de Surfaces et Interfaces, 23, rue du Loess, BP 43, 67034 Strasbourg (France); Anselme, K. [IS2M - Equipe Interaction Surface-Matiere Vivant, 15, rue Jean Starcky, BP 2488, 68057 Mulhouse (France); Mille, P.; Pelletier, H. [INSA - Groupe Ingenierie des Surfaces, 24, Bld de la Victoire, 67084 Strasbourg (France)

2010-05-25

We propose here the use of cathodic electrodeposition as tool to fabricate implant coatings consisting in nano/micro single crystals of hydroxyapatite (HA), preferentially orientated along the c-axis. Coating characterization is the base of this work, where we discuss the mechanisms related to the deposition of oriented hydroxyapatite thin films. It is shown that when deposited on titanium alloys, the HA coating is constituted by two distinct regions with different morphologies: at a distance of few microns from the substrate, large HA single crystals are oriented along the c-axis and appear to grow up from a base material, consisting in an amorphous HA. This organized system has a great importance for cell investigation once the variables involved in the cell/surface interaction are reduced. The use of such systems could give a new insight on the effect of particular HA orientation on the osteoblast cells.

Use of micrometric latex beads to improve the porosity of hydroxyapatite obtained by chemical coprecipitation method

Science.gov (United States)

Webler, G. D.; Rodrigues, W. C.; Silva, A. E. S.; Silva, A. O. S.; Fonseca, E. J. S.; Degenhardt, M. F. S.; Oliveira, C. L. P.; Otubo, L.; Barros Filho, D. A.

2018-04-01

Hydroxyapatite is one of the most important biomaterials whose application mainly extends to implants and drug delivery. This work will discuss the changes in the pore size distribution of hydroxyapatite when there are latex beads present during the synthesis. These changes were monitored using different techniques: small angle X-ray scattering, X-ray diffraction, thermal gravimetrical analysis, N2 adsorption, scanning and transmission electron microscopy. Latex beads and hydroxyapatite form a single nanocomposite with well-distinguished inorganic and organic phases. Latex bead removal in the temperature range of 300-600 °C did not modify the original crystalline structure of hydroxyapatite. However, the latex beads favored an increase in the adsorption capacity of mesopores at temperatures higher than their glassy transition (Tg). The main result of this research work consists on the increase of surface area and pore size distribution obtained after the removal of latex beads template. Latex beads have been used in a different approach changing the porosity of hydroxyapatite scaffolds not only introducing new routes for cell integration but also broadening the pore size distribution which can result in a more high efficiency for drug release in living cells.

Hydroxyapatite formation on titania-based materials in a solution mimicking body fluid: Effects of manganese and iron addition in anatase.

Science.gov (United States)

Shin, Euisup; Kim, Ill Yong; Cho, Sung Baek; Ohtsuki, Chikara

2015-03-01

Hydroxyapatite formation on the surfaces of implanted materials plays an important role in osteoconduction of bone substitutes in bone tissues. Titania hydrogels are known to instigate hydroxyapatite formation in a solution mimicking human blood plasma. To date, the relationship between the surface characteristics of titania and hydroxyapatite formation on its surface remains unclear. In this study, titania powders with varying surface characteristics were prepared by addition of manganese or iron to examine hydroxyapatite formation in a type of simulated body fluid (Kokubo solution). Hydroxyapatite formation was monitored by observation of deposited particles with scale-like morphology on the prepared titania powders. The effect of the titania surface characteristics, i.e., crystal structure, zeta potential, hydroxy group content, and specific surface area, on hydroxyapatite formation was examined. Hydroxyapatite formation was observed on the surface of titania powders that were primarily anatase, and featured a negative zeta potential and low specific surface areas irrespective of the hydroxy group content. High specific surface areas inhibited the formation of hydroxyapatite because calcium and phosphate ions were mostly consumed by adsorption on the titania surface. Thus, these surface characteristics of titania determine its osteoconductivity following exposure to body fluid. Copyright © 2014 Elsevier B.V. All rights reserved.

Does hydroxyapatite coating have no advantage over porous coating in primary total hip arthroplasty? A meta-analysis.

Science.gov (United States)

Chen, Yun-Lin; Lin, Tiao; Liu, An; Shi, Ming-Min; Hu, Bin; Shi, Zhong-Li; Yan, Shi-Gui

2015-01-28

There are some arguments between the use of hydroxyapatite and porous coating. Some studies have shown that there is no difference between these two coatings in total hip arthroplasty (THA), while several other studies have shown that hydroxyapatite has advantages over the porous one. We have collected the studies in Pubmed, MEDLINE, EMBASE, and the Cochrane library from the earliest possible years to present, with the search strategy of "(HA OR hydroxyapatite) AND ((total hip arthroplasty) OR (total hip replacement)) AND (RCT* OR randomiz* OR control* OR compar* OR trial*)". The randomized controlled trials and comparative observation trials that evaluated the clinical and radiographic effects between hydroxyapatite coating and porous coating were included. Our main outcome measurements were Harris hip score (HHS) and survival, while the secondary outcome measurements were osteolysis, radiolucent lines, and polyethylene wear. Twelve RCTs and 9 comparative observation trials were included. Hydroxyapatite coating could improve the HHS (p hydroxyapatite coating had no advantages on survival (p = 0.32), polyethylene wear (p = 0.08), and radiolucent lines (p = 0.78). Hydroxyapatite coating has shown to have an advantage over porous coating. The HHS and survival was duration-dependent-if given the sufficient duration of follow-up, hydroxyapatite coating would be better than porous coating for the survival. The properties of hydroxyapatite and the implant design had influence on thigh pain incidence, femoral osteolysis, and polyethylene wear. Thickness of 50 to 80 μm and purity larger than 90% increased the thigh pain incidence. Anatomic design had less polyethylene wear.

Higher dose of palonosetron versus lower dose of palonosetron plus droperidol to prevent postoperative nausea and vomiting after eye enucleation and orbital hydroxyapatite implant surgery: a randomized, double-blind trial

Directory of Open Access Journals (Sweden)

Hu X

2017-05-01

Full Text Available Xiao Hu, Fang Tan, Lan Gong Department of Anesthesiology, The Eye, Ear, Nose and Throat Hospital of Fudan University, Shanghai Medical College of Fudan University, Shanghai, China Objective: Postoperative nausea and vomiting (PONV is commonly observed after eye enucleation and orbital hydroxyapatite implant surgery. This prospective, randomized, double-blind trial was conducted to investigate the hypothesis that compared with monotherapy using a higher dose of palonosetron, using a lower dose of palonosetron in combination with droperidol could reduce the incidence of PONV and achieve similar prophylaxis against PONV after the aforementioned surgery.Patients and methods: A total of 129 patients who were in the American Society of Anesthesiologists Classes I and II, aged between 18 and 70 years, and scheduled for eye enucleation and orbital hydroxyapatite implant surgery, were enrolled in this study. They were randomized into three groups: Group P2.5 (2.5 µg/kg palonosetron, Group P7.5 (7.5 µg/kg palonosetron, and Group P+D (2.5 µg/kg palonosetron and 15 µg/kg droperidol. Patients received the different antiemetic regimens intravenously 5 min before surgery. The severity of nausea and vomiting and the complete response (CR rate during a 72-h postoperative period were assessed.Results: All patients completed the trial. The nausea score of Group P2.5 was significantly higher than those of the other two groups at 0–4 h and 24–48 h (P<0.05. Vomiting scores among all groups were similar during all intervals (P>0.05. Compared with Group P2.5, the CR rate was significantly improved at all intervals in Group P+D, except at 4–72 h, and was also elevated at 24–72 h in Group P7.5 (P<0.05. Fewer patients in Group P2.5 did not experience any nausea or vomiting throughout the study (49% compared with those in Group P7.5 (67% and Group P+D (81%; P<0.01.Conclusion: Combining low-dose palonosetron with droperidol potentiated prophylaxis

Biological and physical properties of pulsed-laser-deposited zirconia/hydroxyapatite on titanium: in vitro study

Czech Academy of Sciences Publication Activity Database

Teuberová, Z.; Seydlová, M.; Dostálová, T.; Dvořánková, B.; Smetana, K. Jr.; Jelínek, Miroslav; Mašínová, Petra; Kocourek, Tomáš; Kolářová, K.; Wilson, J.

2007-01-01

Roč. 17, č. 1 (2007), s. 45-49 ISSN 1054-660X R&D Projects: GA MZd NR8512 Institutional research plan: CEZ:AV0Z10100522 Keywords : dental implants * hydroxyapatite * titanium * laser deposition * PLD Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.696, year: 2007

Implant Stability of Biological Hydroxyapatites Used in Dentistry

Directory of Open Access Journals (Sweden)

Maria Piedad Ramírez Fernández

2017-06-01

Full Text Available The aim of the present study was to monitor implant stability after sinus floor elevation with two biomaterials during the first six months of healing by resonance frequency analysis (RFA, and how physico-chemical properties affect the implant stability quotient (ISQ at the placement and healing sites. Bilateral maxillary sinus augmentation was performed in 10 patients in a split-mouth design using a bobine HA (BBM as a control and porcine HA (PBM. Six months after sinus lifting, 60 implants were placed in the posterior maxilla. The ISQ was recorded on the day of surgery from RFA at T1 (baseline, T2 (three months, and T3 (six months. Statistically significant differences were found in the ISQ values during the evaluation period. The ISQ (baseline was 63.8 ± 2.97 for BBM and 62.6 ± 2.11 for PBM. The ISQ (T2 was ~73.5 ± 4.21 and 67 ± 4.99, respectively. The ISQ (T3 was ~74.65 ± 2.93 and 72.9 ± 2.63, respectively. All of the used HAs provide osseointegration and statistical increases in the ISQ at baseline, T2 and T3 (follow-up, respectively. The BBM, sintered at high temperature with high crystallinity and low porosity, presented higher stability, which demonstrates that variations in the physico-chemical properties of a bone substitute material clearly influence implant stability.

Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

Science.gov (United States)

Parcharoen, Yardnapar; Kajitvichyanukul, Puangrat; Sirivisoot, Sirinrath; Termsuksawad, Preecha

2014-08-01

Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO2) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO2 nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH4F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO2 nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO2 nanotubes were found when high viscous electrolyte, NH4F in glycerol, was used. Negative voltage (-4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO2 nanotubes was significantly increased by times. The TiO2 nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO2 nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that growing on titanium plate surface.

In Vitro Evaluation of Nanoscale Hydroxyapatite-Based Bone Reconstructive Materials with Antimicrobial Properties.

Science.gov (United States)

Ajduković, Zorica R; Mihajilov-Krstev, Tatjana M; Ignjatović, Nenad L; Stojanović, Zoran; Mladenović-Antić, Snezana B; Kocić, Branislava D; Najman, Stevo; Petrović, Nenad D; Uskoković, Dragan P

2016-02-01

In the field of oral implantology the loss of bone tissue prevents adequate patient care, and calls for the use of synthetic biomaterials with properties that resemble natural bone. Special attention is paid to the risk of infection after the implantation of these materials. Studies have suggested that some nanocontructs containing metal ions have antimicrobial properties. The aim of this study was to examine the antimicrobial and hemolytic activity of cobalt-substituted hydroxyapatite nanoparticles, compared to hydroxyapatite and hydroxyapatite/poly-lactide-co-glycolide. The antibacterial effects of these powders were tested against two pathogenic bacterial strains: Escherichia coi (ATCC 25922) and Staphylococcus aureus (ATCC 25923), using the disc diffusion method and the quantitative antimicrobial test in a liquid medium. The quantitative antimicrobial test showed that all of the tested biomaterials have some antibacterial properties. The effects of both tests were more prominent in case of S. aureus than in E coli. A higher percentage of cobalt in the crystal structure of cobalt-substituted hydroxyapatite nanoparticles led to an increased antimicrobial activity. All of the presented biomaterial samples were found to be non-hemolytic. Having in mind that the tested of cobalt-substituted hydroxyapatite (Ca/Co-HAp) material in given concentrations shows good hemocompatibility and antimicrobial effects, along with its previously studied biological properties, the conclusion can be reached that it is a potential candidate that could substitute calcium hydroxyapatite as the material of choice for use in bone tissue engineering and clinical practices in orthopedic, oral and maxillofacial surgery.

No effect of platelet-rich plasma with frozen or processed bone allograft around noncemented implants

DEFF Research Database (Denmark)

Jensen, T B; Rahbek, O; Overgaard, S

2005-01-01

by isolating the buffy coat from autologous blood samples. Bone allograft was used fresh-frozen or processed by defatting, freeze drying, and irradiation. Cylindrical hydroxyapatite-coated titanium implants were inserted bilaterally in the femoral condyles of eight dogs. Each implant was surrounded by a 2.5-mm...

Nanostructured Si-substituted hydroxyapatite coatings for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Rau, Julietta V., E-mail: giulietta.rau@ism.cnr.it [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Fosca, Marco [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133 Rome (Italy); Cacciotti, Ilaria [Università di Roma “Tor Vergata”, Dipartimento di Ingegneria Industriale,UR INSTM “Roma Tor Vergata”, Via del Politecnico, 1-00133 Rome (Italy); Laureti, Sara [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via Salaria km 29.300-00016 Monterotondo Scalo (RM) (Italy); Bianco, Alessandra [Università di Roma “Tor Vergata”, Dipartimento di Ingegneria Industriale,UR INSTM “Roma Tor Vergata”, Via del Politecnico, 1-00133 Rome (Italy); Teghil, Roberto [Università della Basilicata, Dipartimento di Scienze, Via dell' Ateneo Lucano 10-85100, Potenza (Italy)

2013-09-30

In the present work, the Si-HAp coatings were deposited on titanium substrates by Pulsed Laser Deposition technique. For deposition, the Si-HAp targets (1.4 wt.% of Si), produced starting from wet synthesized powders, were used. The properties of coatings were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and Vickers microhardness. The obtained Si-HAp coatings presented a nanosized structure, proper thickness and hardness for applications in orthopedical and dental surgery, aimed at improving the stability and the osteointegration of bone implants. - Highlights: ► Pulsed Laser Deposition method was applied to coat heated Titanium supports. ► Films were deposited using a target of Silicon-Hydroxyapatite sintered ceramics. ► Nanostructured crystalline hard film was grown replicating target composition. ► Prepared coating could be used for orthopedic and dental implants applications.

Nanostructured Si-substituted hydroxyapatite coatings for biomedical applications

International Nuclear Information System (INIS)

Rau, Julietta V.; Fosca, Marco; Cacciotti, Ilaria; Laureti, Sara; Bianco, Alessandra; Teghil, Roberto

2013-01-01

In the present work, the Si-HAp coatings were deposited on titanium substrates by Pulsed Laser Deposition technique. For deposition, the Si-HAp targets (1.4 wt.% of Si), produced starting from wet synthesized powders, were used. The properties of coatings were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and Vickers microhardness. The obtained Si-HAp coatings presented a nanosized structure, proper thickness and hardness for applications in orthopedical and dental surgery, aimed at improving the stability and the osteointegration of bone implants. - Highlights: ► Pulsed Laser Deposition method was applied to coat heated Titanium supports. ► Films were deposited using a target of Silicon-Hydroxyapatite sintered ceramics. ► Nanostructured crystalline hard film was grown replicating target composition. ► Prepared coating could be used for orthopedic and dental implants applications

Hydroxyapatite coating on stainless steel by biomimetic method

International Nuclear Information System (INIS)

Dias, V.M.; Maia Filho, A.L.M.; Silva, G.; Sousa, E. de; Cardoso, K.R.

2010-01-01

Austenitic stainless steels are widely used in implants due to their high mechanical strength and corrosion, however, are not able to connect to bone tissue and were classified as bioinert. The calcium phosphate ceramics such as hydroxyapatite (HA) are bioactive materials and create strong chemical bonds with bone tissue, but its brittleness and low fracture toughness render its use in conditions of high mechanical stress. The coating of steel with the bioactive ceramics such as HA, combines the properties of interest of both materials, accelerating bone formation around the implant. In this study, austenitic stainless steel samples were coated with apatite using the biomimetic method. The effect of three different surface conditions of steel and the immersion time in the SBF solution on the coating was evaluated. The samples were characterized by SEM, EDS and X-ray diffraction. (author)

Hydroxyapatite-coated double network hydrogel directly bondable to the bone: Biological and biomechanical evaluations of the bonding property in an osteochondral defect.

Science.gov (United States)

Wada, Susumu; Kitamura, Nobuto; Nonoyama, Takayuki; Kiyama, Ryuji; Kurokawa, Takayuki; Gong, Jian Ping; Yasuda, Kazunori

2016-10-15

We have developed a novel hydroxyapatite (HAp)-coated double-network (DN) hydrogel (HAp/DN gel). The purpose of this study was to determine details of the cell and tissue responses around the implanted HAp/DN gel and to determine how quickly and strongly the HAp/DN gel bonds to the bone in a rabbit osteochondral defect model. Immature osteoid tissue was formed in the space between the HAp/DN gel and the bone at 2weeks, and the osteoid tissue was mineralized at 4weeks. The push-out load of the HAp/DN gel averaged 37.54N and 42.15N at 4 and 12weeks, respectively, while the push-out load of the DN gel averaged less than 5N. The bonding area of the HAp/DN gel to the bone was above 80% by 4weeks, and above 90% at 12weeks. This study demonstrated that the HAp/DN gel enhanced osseointegration at an early stage after implantation. The presence of nanoscale structures in addition to osseointegration of HAp promoted osteoblast adhesion onto the surface of the HAp/DN gel. The HAp/DN gel has the potential to improve the implant-tissue interface in next-generation orthopaedic implants such as artificial cartilage. Recent studies have reported the development of various hydrogels that are sufficiently tough for application as soft supporting tissues. However, fixation of hydrogels on bone surfaces with appropriate strength is a great challenge. We have developed a novel, tough hydrogel hybridizing hydroxyapatite (HAp/DN gel), which is directly bondable to the bone. The present study demonstrated that the HAp/DN gel enhanced osseointegration in the early stage after implantation. The presence of nanoscale structures in addition to the osseointegration ability of hydroxyapatite promoted osteoblast adhesion onto the surface of the HAp/DN gel. The HAp/DN gel has the potential to improve the implant-tissue interface in next-generation orthopaedic implants such as artificial cartilage. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Changes in anterior ocular structures and macula following deep sclerectomy with collagen implant.

Science.gov (United States)

Suominen, Sakari M A; Harju, Mika P; Hautamäki, Asta M E; Vesti, Eija T

2018-01-01

To determine the effect of intraocular pressure (IOP) lowering with deep sclerectomy (DS) on visual acuity, macular structures, and anterior ocular dimensions during the early postoperative period. We prospectively analyzed 35 eyes of 35 patients scheduled for DS. Our focus with the measurements was on early postoperative changes in anterior ocular and macular structures related to IOP lowering during the first month after DS. In addition to a clinical ophthalmologic examination, our measurements included corneal topography, measurement of ocular dimensions with optical biometry, and examination of macular structure with optical coherence tomography. These measurements were repeated 1, 2, and 4 weeks postoperatively. Best-corrected visual acuity (BCVA) decreased 1 week postoperatively to 0.22 (0.20) LogMAR (p = 0.006). The BCVA then increased to its preoperative level, 0.17 (0.18) (p = 0.28), after 4 weeks. Axial length decreased from 24.12 (1.81) mm to 24.04 (1.81) (p<0.001) 4 weeks postoperatively. The steeper meridian of corneal curvature and average corneal power increased postoperatively; central corneal thickness was decreased. No significant change appeared in other measurements. We found changes in corneal curvature and ocular dimensions after DS. These changes were relatively small and do not completely explain the decrease in visual acuity postoperatively. Macular structures showed no changes.

Implantation of silicon dioxide-based nanocrystalline hydroxyapatite and pure phase beta-tricalciumphosphate bone substitute granules in caprine muscle tissue does not induce new bone formation

Directory of Open Access Journals (Sweden)

Ghanaati Shahram

2013-01-01

Full Text Available Abstract Background Osteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue. Materials and methods One gram each of either a porous beta-tricalcium phosphate (β-TCP or an hydroxyapatite/silicon dioxide (HA/SiO2-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix. Results Both materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points. Conclusions This study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting.

Structure–property relationships of iron–hydroxyapatite ceramic matrix nanocomposite fabricated using mechanosynthesis method

Energy Technology Data Exchange (ETDEWEB)

Nordin, Jamillah Amer [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Prajitno, Djoko Hadi [Nuclear Technology Center for Materials and Radiometry, National Nuclear Energy, Bandung 40132 (Indonesia); Saidin, Syafiqah [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Nur, Hadi, E-mail: hadi@kimia.fs.utm.my [Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Department of Physics, Institut Sains dan Teknologi Nasional, Jl. Moh. Kahfi II, Jagakarsa, Jakarta Selatan 12640 (Indonesia); Hermawan, Hendra, E-mail: hendra.hermawan@gmn.ulaval.ca [Department of Mining, Metallurgical and Materials Engineering & CHU de Québec Research Center, Laval University, Québec City G1V 0A6 (Canada)

2015-06-01

Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone–implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12 h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12 h milling in the presence of HPO{sub 4}{sup 2−} ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12 h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis - Highlights: • Improvement of mechanical properties of HAp bioceramics by mechanosynthesis method • Structure–property relationship of iron–hydroxyapatite ceramic matrix nanocomposite • Milling time influenced the properties of iron–hydroxyapatite ceramic matrix nanocomposite.

Structure–property relationships of iron–hydroxyapatite ceramic matrix nanocomposite fabricated using mechanosynthesis method

International Nuclear Information System (INIS)

Nordin, Jamillah Amer; Prajitno, Djoko Hadi; Saidin, Syafiqah; Nur, Hadi; Hermawan, Hendra

2015-01-01

Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone–implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12 h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12 h milling in the presence of HPO 4 2− ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12 h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis - Highlights: • Improvement of mechanical properties of HAp bioceramics by mechanosynthesis method • Structure–property relationship of iron–hydroxyapatite ceramic matrix nanocomposite • Milling time influenced the properties of iron–hydroxyapatite ceramic matrix nanocomposite

Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants

Energy Technology Data Exchange (ETDEWEB)

Gryshkov, Oleksandr, E-mail: gryshkov@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany); Klyui, Nickolai I., E-mail: klyuini@ukr.net [College of Physics, Jilin University, 130012 Changchun (China); V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Temchenko, Volodymyr P., E-mail: tvp@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Kyselov, Vitalii S., E-mail: kyselov@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Chatterjee, Anamika, E-mail: chatterjee@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany); Belyaev, Alexander E., E-mail: belyaev@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Lauterboeck, Lothar, E-mail: lauterboeck@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany); Iarmolenko, Dmytro, E-mail: iarmolenko.dmytro@isp.kiev.ua [V. Lashkaryov Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028 Kyiv (Ukraine); Glasmacher, Birgit, E-mail: glasmacher@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz Universität Hannover, 30167 Hannover (Germany)

2016-11-01

Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO{sub 2}) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO{sub 2} using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO{sub 2} to the initial HA powder resulted in significant decomposition of the final HA/ZrO{sub 2} coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO{sub 2} coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. - Highlights: • Synthesis and characterization of porous biomorphic SiC ceramics derived from wood • Successful deposition of bioactive calcium phosphate coatings using gas detonation deposition • Porosity and pore size of Si

Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants

International Nuclear Information System (INIS)

Gryshkov, Oleksandr; Klyui, Nickolai I.; Temchenko, Volodymyr P.; Kyselov, Vitalii S.; Chatterjee, Anamika; Belyaev, Alexander E.; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

2016-01-01

Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO 2 ) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO 2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO 2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO 2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO 2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application. - Highlights: • Synthesis and characterization of porous biomorphic SiC ceramics derived from wood • Successful deposition of bioactive calcium phosphate coatings using gas detonation deposition • Porosity and pore size of SiC ceramics depend on wood

Ocular Hypertension

Science.gov (United States)

... Español Eye Health / Eye Health A-Z Ocular Hypertension Sections What Is Ocular Hypertension? Ocular Hypertension Causes ... Hypertension Diagnosis Ocular Hypertension Treatment What Is Ocular Hypertension? Leer en Español: ¿Qué es la hipertensión ocular? ...

Do Bone Graft and Cracking of the Sclerotic Cavity Improve Fixation of Titanium and Hydroxyapatite-coated Revision Implants in an Animal Model?

Science.gov (United States)

Elmengaard, Brian; Baas, Joergen; Jakobsen, Thomas; Kold, Soren; Jensen, Thomas B; Bechtold, Joan E; Soballe, Kjeld

2017-02-01

We previously introduced a manual surgical technique that makes small perforations (cracks) through the sclerotic bone shell that typically forms during the process of aseptic loosening ("crack" revision technique). Perforating just the shell (without violating the proximal cortex) can maintain overall bone continuity while allowing marrow and vascular elements to access the implant surface. Because many revisions require bone graft to fill defects, we wanted to determine if bone graft could further increase implant fixation beyond what we have experimentally shown with the crack technique alone. Also, because both titanium (Ti6Al4V) and hydroxyapatite (HA) implant surfaces are used in revisions, we also wanted to determine their relative effectiveness in this model. We hypothesized that both (1) allografted plasma-sprayed Ti6Al4V; and (2) allografted plasma-sprayed HA-coated implants inserted with a crack revision technique have better fixation compared with a noncrack revision technique in each case. Under approval from our Institutional Animal Care and Use Committee, a female canine animal model was used to evaluate the uncemented revision technique (crack, noncrack) using paired contralateral implants while implant surface (Ti6Al4V, HA) was qualitatively compared between the two (unpaired) series. All groups received bone allograft tightly packed around the implant. This revision model includes a cylindrical implant pistoning 500 μm in a 0.75-mm gap, with polyethylene particles, for 8 weeks. This engenders a bone and tissue response representative of the metaphyseal cancellous region of an aseptically loosened component. At 8 weeks, the original implants were revised and followed for an additional 4 weeks. Mechanical fixation was assessed by load, stiffness, and energy to failure when loaded in axial pushout. Histomorphometry was used to determine the amount and location of bone and fibrous tissue in the grafted gap. The grafted crack revision improved

Structural, compositional, mechanical characterization and biological assessment of bovine-derived hydroxyapatite coatings reinforced with MgF_2 or MgO for implants functionalization

International Nuclear Information System (INIS)

Mihailescu, Natalia; Stan, G.E.; Duta, L.; Chifiriuc, Mariana Carmen; Bleotu, Coralia; Sopronyi, M.; Luculescu, C.; Oktar, F.N.; Mihailescu, I.N.

2016-01-01

Hydroxyapatite (HA) is a consecrated biomaterial for bone reconstruction. In the form of thin films deposited by pulsed laser technologies, it can be used to cover metallic implants aiming to increase biocompatibility and osseointegration rate. HA of animal origin (bovine, BHA) reinforced with MgF_2 (2 wt.%) or MgO (5 wt.%) were used for deposition of thin coatings with improved adherence, biocompatibility and antimicrobial activity. For pulsed laser deposition experiments, a KrF* (λ = 248 nm, τ_F_W_H_M ≤ 25 ns) excimer laser source was used. The deposited structures were characterized from a physical–chemical point of view by X-Ray Diffraction, Fourier Transform Infra-Red Spectroscopy, Scanning Electron Microscopy in top- and cross-view modes, Energy Dispersive X-Ray Spectroscopy and Pull-out adherence tests. The microbiological assay using the HEp-2 cell line revealed that all target materials and deposited thin films are non-cytotoxic. We conducted tests on three strains isolated from patients with dental implants failure, i.e. Microccocus sp., Enterobacter sp. and Candida albicans sp. The most significant anti-biofilm effect against Microcococcus sp. strain, at 72 h, was obtained in the presence of BHA:MgO thin films. For Enterobacter sp. strain a superior antimicrobial activity at 72 h was noticed, in respect with simple BHA or Ti control. The enhanced antimicrobial performances, correlated with good cytocompatibility and mechanical properties recommend these biomaterials as an alternative to synthetic HA for the fabrication of reliable implant coatings for dentistry and other applications. - Highlights: • Novel biological derived HA coatings fabricated by pulsed laser deposition. • Renewable resources • Reinforcement with MgF_2 and MgO improves the HA coatings' bonding strength. • Significant anti-biofilm effect obtained for MgO reinforced HA films. • Alternative low cost solutions for a new generation of dental implants.

Biomineralization of hydroxyapatite in silver ion-exchanged nanocrystalline ZSM-5 zeolite using simulated body fluid.

Science.gov (United States)

Kaur, Balwinder; Srivastava, Rajendra; Satpati, Biswarup; Kondepudi, Kanthi Kiran; Bishnoi, Mahendra

2015-11-01

Silver ion-exchanged nanocrystalline zeolite (Ag-Nano-ZSM-5) and silver ion-exchanged conventional zeolite (Ag-ZSM-5) were synthesized. Zeolites were incubated in simulated body fluid at 310K for different time periods to grow hydroxyapatite in their matrixes. Significant large amount of hydroxyapatite was grown in Ag-Nano-ZSM-5 matrix after incubation in simulated body fluid when compared to Ag-ZSM-5. The resultant material was characterized using X-ray diffraction, N2-adsorption, scanning/transmission electron microscopy, energy dispersive X-ray, and inductively coupled plasma analysis. Mechanical properties such as compressive modulus, compressive strength, and strain at failure of the parent materials were evaluated. Biocompatibility assays suggested that Ag-Nano-ZSM-5 and hydroxyapatite grown in Ag-Nano-ZSM-5 were compatible and did not impose any toxicity to RAW 264.7 cells macrophase and Caco2 cells suggesting considerable potential for biomedical applications such as bone implants. Copyright © 2015 Elsevier B.V. All rights reserved.

Examination of Sol-Gel Derived Hydroxyapatite Enhanced with Silver Nanoparticles using OCT and Raman Spectroscopy

Directory of Open Access Journals (Sweden)

Głowacki Maciej J.

2017-03-01

Full Text Available Hydroxyapatite (HAp has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements of HAp molecular composition and solvent evaporation efficiency the Raman spectroscopy has been chosen. In order to evaluate dispersion and concentration of the silver nanoparticles inside the hydroxyapatite matrix, the optical coherence tomography (OCT has been used. Five samples were developed and examined ‒ a reference sample of pure HAp sol and four samples of HAp colloids with different silver nanoparticle solution volume ratios. The Raman spectra for each solution have been obtained and analyzed. Furthermore, a transverse-sectional visualization of every sample has been created and examined by means of OCT.

Thermal Diffusivity in Bone and Hydroxyapatite

Science.gov (United States)

Calderón, A.; Peña Rodríguez, G.; Muñoz Hernández, R. A.; Díaz Gongora, J. A. I.; Mejia Barradas, C. M.

2004-09-01

We report thermal diffusivity measurements in bull bone and commercial hydroxyapatite (HA), both in powder form, in order to determinate the thermal compatibility between these materials. Besides this, we report a comparison between these measured values and those of metallic samples frequently used in implants, as high purity titanium and stainless steel. Our results show a good thermal compatibility (74%) between HA and bone, both in powder form. Finally, it was obtained a one order of magnitude difference between the thermal diffusivity values of metallic samples and those corresponding values to bone and HA being this difference greater in titanium than in stainless steel, which is important to consider in some biomedical and dental applications.

Immobilisation of hydroxyapatite-collagen on polydopamine grafted stainless steel 316L: Coating adhesion and in vitro cells evaluation.

Science.gov (United States)

Tapsir, Zafirah; Jamaludin, Farah H; Pingguan-Murphy, Belinda; Saidin, Syafiqah

2018-02-01

The utilisation of hydroxyapatite and collagen as bioactive coating materials could enhance cells attachment, proliferation and osseointegration. However, most methods to form crystal hydroxyapatite coating do not allow the incorporation of polymer/organic compound due to production phase of high sintering temperature. In this study, a polydopamine film was used as an intermediate layer to immobilise hydroxyapatite-collagen without the introduction of high sintering temperature. The surface roughness, coating adhesion, bioactivity and osteoblast attachment on the hydroxyapatite-collagen coating were assessed as these properties remains unknown on the polydopamine grafted film. The coating was developed by grafting stainless steel 316L disks with a polydopamine film. Collagen type I fibres were then immobilised on the grafted film, followed by the biomineralisation of hydroxyapatite. The surface roughness and coating adhesion analyses were later performed by using AFM instrument. An Alamar Blue assay was used to determine the cytotoxicity of the coating, while an alkaline phosphatase activity test was conducted to evaluate the osteogenic differentiation of human fetal osteoblasts on the coating. Finally, the morphology of cells attachment on the coating was visualised under FESEM. The highest RMS roughness and coating adhesion were observed on the hydroxyapatite-collagen coating (hydroxyapatite-coll-dopa). The hydroxyapatite-coll-dopa coating was non-toxic to the osteoblast cells with greater cells proliferation, greater level of alkaline phosphate production and more cells attachment. These results indicate that the immobilisation of hydroxyapatite and collagen using an intermediate polydopamine is identical to enhance coating adhesion, osteoblast cells attachment, proliferation and differentiation, and thus could be implemented as a coating material on orthopaedic and dental implants.

[Clinical and ossification outcome of custom-made hydroxyapatite prothese for large skull defect].

Science.gov (United States)

Hardy, H; Tollard, E; Derrey, S; Delcampe, P; Péron, J-M; Fréger, P; Proust, F

2012-02-01

Cranioplasty is an everyday concern in neurosurgery, especially in decompressive craniectomy cases. Our surgical team uses custom-made hydroxyapatite implants for large and/or complex defects. Eight patients had a custom-made prosthesis. Each of them has been reviewed by an independent observer. Each patient described his feeling of satisfaction, using a questionnaire, graduated from "A" (really satisfied) to "D" (unsatisfied). Each of them also underwent a CT-scan (helicoidal acquisition, 0.6mm thick for multiplanar reconstruction) to evaluate qualitatively the ossification graduated from "0" (no ossification) to "5" (continuous ossification). Maximal under-prosthetic bone thickness, intra-prosthetic calcic density were also reported. Supervision delay was 43.7 months [6-99 months], average defect surface was 85.5 cm(2) [27.6-137.6 cm(2)], the craniectomy etiologies were intracranial hypertension (seven patients) and calvarial invasion (one patient). Implant tolerance was reparted in "A" score (50%) and "B" score (50%). Concerning ossification, six patients (75%) had a score of "2" or less and two patients had a score of "3" or "4". Hydroxyapatite custom-made implants for cranioplasty appear to be ideal for good aesthetic and tolerance results, but their ossification is hardly analyzed due to the prosthesis density higher than the bone's density. This is why we recommend them for children and in cases of complex defects such as pterion location. Copyright © 2011. Published by Elsevier Masson SAS.

Nanocarriers in ocular drug delivery: an update review.

Science.gov (United States)

Wadhwa, Sheetu; Paliwal, Rishi; Paliwal, Shivani Rai; Vyas, S P

2009-01-01

Controlled drug delivery to eye is one of the most challenging fields of pharmaceutical research. Low drug-contact time and poor ocular bioavailability due to drainage of solution, tear turnover and its dilution or lacrimation are the problems associated with conventional systems. In addition, anatomical barriers and physiological conditions of eye are also important parameters which control designing of drug delivery systems. Nanosized carriers like micro/nano-suspensions, liposome, niosome, dendrimer, nanoparticles, ocular inserts, implants, hydrogels and prodrug approaches have been developed for this purpose. These novel systems offer manifold advantages over conventional systems as they increase the efficiency of drug delivery by improving the release profile and also reduce drug toxicity. Conventional delivery systems get diluted with tear, washed away through the lacrimal gland and usually require administering at regular time intervals whereas nanocarriers release drug at constant rate for a prolonged period of time and thus enhance its absorption and site specific delivery. This review presents an overview of the various aspects of the ocular drug delivery, with special emphasis on nanocarrier based strategies, including structure of eye, its barriers, delivery routes and the challenges/limitations associated with development of novel nanocarriers. The recent progresses in therapy of ocular disease like gene therapy have also been included so that future options should also be considered from the delivery point of view. Recent progress in the delivery of proteins and peptides via ocular route has also been incorporated for reader benefit.

Electrospun Nanocomposite Materials, A Novel Synergy of Polyurethane and Bovine Derived Hydroxyapatite

Science.gov (United States)

Bozkurt, Y.; Sahin, A.; Sunulu, A.; Aydogdu, M. O.; Altun, E.; Oktar, F. N.; Ekren, N.; Gunduz, O.

2017-04-01

Polyurethane (PU) is a synthetic polymer that is used for construction of scaffold in tissue engineering applications in order to obtain desirable mechanical, physical and chemical properties like elasticity and durability. Bovine derived hydroxyapatite (BHAp) is a ceramic based natural polymer that is used as the most preferred implant material in orthopedics and dentistry due to their chemically and biologically similarity to the mineral phase found in the human bone structure. PU and bovine derived hydroxyapatite (BHAp) solutions with different concentrations were prepared with dissolving polyurethane and BHAp in Dimethylformamide (DMF) and Tetrahydrofuran (THF) solutions. Blended PU-BHAp solutions in different concentrations were used for electrospinning technique to create nanofiber scaffolds and new biocomposite material together. SEM, FTIR and physical analysis such as viscosity, electrical conductivity, density measurement and tensile strength measurement tests were carried out after production process.

Effect of the deposition temperature on corrosion resistance and biocompatibility of the hydroxyapatite coatings

Energy Technology Data Exchange (ETDEWEB)

Vladescu, A., E-mail: alinava@inoe.ro [National Institute for Optoelectronics, 409 Atomistilor Str., Magurele (Romania); Braic, M. [National Institute for Optoelectronics, 409 Atomistilor Str., Magurele (Romania); Azem, F. Ak [Dokuz Eylul University, Engineering Faculty, Metallurgical and Materials Engineering Department, Buca-Izmir (Turkey); Titorencu, I. [Institute of Cellular Biology and Pathology Nicolae Simionescu of the Romanian Academy, 8 B.P.Hasdeu, Bucharest (Romania); Braic, V. [National Institute for Optoelectronics, 409 Atomistilor Str., Magurele (Romania); Pruna, V. [Institute of Cellular Biology and Pathology Nicolae Simionescu of the Romanian Academy, 8 B.P.Hasdeu, Bucharest (Romania); Kiss, A. [National Institute for Optoelectronics, 409 Atomistilor Str., Magurele (Romania); Parau, A.C.; Birlik, I. [Dokuz Eylul University, Engineering Faculty, Metallurgical and Materials Engineering Department, Buca-Izmir (Turkey)

2015-11-01

Highlights: • Hydroxyapatite has been produced at temperature from 400 to 800 °C by magnetron sputtering. • Hydroxyapatite crystallinity is improved by increasing substrate temperature. • The increase of substrate temperature resulted in corrosion resistance increasing. • The coating shows high growth of the osteosarcoma cells over a wide temperature range. - Abstract: Hydroxyapatite (HAP) ceramics belong to a class of calcium phosphate-based materials, which have been widely used as coatings on titanium medical implants in order to improve bone fixation and thus to increase the lifetime of the implant. In this study, HAP coatings were deposited from pure HAP targets on Ti6Al4V substrates using the radio-frequency magnetron sputtering technique at substrate temperatures ranging from 400 to 800 °C. The surface morphology and the crystallographic structure of the films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion resistance of the coatings in saliva solution at 37 °C was evaluated by potentiodynamic polarization. Additionally, the human osteosarcoma cell line (MG-63) was used to test the biocompatibility of the coatings. The results showed that all of the coatings grown uniformly and that the increasing substrate temperature induced an increase in their crystallinity. Corrosion performance of the coatings was improved with the increase of the substrate temperature from 400 °C to 800 °C. Furthermore, all the coatings support the attachment and growth of the osteosarcoma cells with regard to the in vitro test findings.

Nanocarrier mediated retinal drug delivery: overcoming ocular barriers to treat posterior eye diseases.

Science.gov (United States)

Bisht, Rohit; Mandal, Abhirup; Jaiswal, Jagdish K; Rupenthal, Ilva D

2018-03-01

Effective drug delivery to the retina still remains a challenge due to ocular elimination mechanisms and complex barriers that selectively limit the entry of drugs into the eye. To overcome these barriers, frequent intravitreal injections are currently used to achieve high drug concentrations in vitreous and retina. However, these repetitive injections may result in several side effects. Recent advancements in the field of nanoparticle-based drug delivery could overcome some of these unmet needs and various preclinical studies conducted to date have demonstrated promising results of nanotherapies in the treatment of retinal diseases. Compared to the majority of commercially available ocular implants, the biodegradable nature of most nanoparticles (NPs) avoids the need for surgical implantation and removal after the release of the payload. In addition, the sustained drug release from NPs over an extended period of time reduces the need for frequent intravitreal injections and the risk of associated side effects. The nanometer size and highly modifiable surface properties make NPs excellent candidates for targeted ocular drug delivery. Studies have shown that nanocarriers enhance the intravitreal half-life and thus bioavailability of a number of drugs including proteins and peptides. In addition, they have shown promising results in delivering genetic material to the retinal tissues by protecting it from possible intravitreal degradation. This review covers the various challenges associated with drug delivery to the posterior segment of the eye, particularly the retina, and highlights the application of nanocarriers to overcome these challenges in context with recent advances in preclinical studies. WIREs Nanomed Nanobiotechnol 2018, 10:e1473. doi: 10.1002/wnan.1473 This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanomaterials and Implants. © 2017 Wiley Periodicals

Thin Bioactive Zn Substituted Hydroxyapatite Coating Deposited on Ultrafine Grained Titanium Substrate: Structure Analysis

Science.gov (United States)

Prosolov, Konstantin A.; Belyavskaya, Olga A.; Muehle, Uwe; Sharkeev, Yurii P.

2018-02-01

Nanocrystalline Zn substituted hydroxyapatite coatings were deposited by radiofrequency magnetron sputtering on the surface of ultrafine-grained titanium substrates. Cross section transmission electron microscopy provided information about the morphology and texture of the thin film while in-column energy dispersive X-ray analysis confirmed the presence of Zn in the coating. The Zn substituted hydroxyapatite coating was formed by an equiaxed polycrystalline grain structure. Effect of substrate crystallinity on the structure of deposited coating is discussed. An amorphous TiO2 sublayer of 8 nm thickness was detected in the interface between the polycrystalline coating and the Ti substrate. Its appearance in the amorphous state is attributed to prior to deposition etching of the substrate and subsequent condensation of oxygen-containing species sputtered from the target. This layer contributes to the high coating-to-substrate adhesion. The major P-O vibrational modes of high intensity were detected by Raman spectroscopy. The Zn substituted hydroxyapatite could be a material of choice when antibacterial osteoconductive coating with a possibility of withstanding mechanical stress during implantation and service is needed.

Thin Bioactive Zn Substituted Hydroxyapatite Coating Deposited on Ultrafine-Grained Titanium Substrate: Structure Analysis

Directory of Open Access Journals (Sweden)

Konstantin A. Prosolov

2018-02-01

Full Text Available Nanocrystalline Zn-substituted hydroxyapatite coatings were deposited by radiofrequency magnetron sputtering on the surface of ultrafine-grained titanium substrates. Cross-section transmission electron microscopy provided information about the morphology and texture of the thin film while in-column energy dispersive X-ray analysis confirmed the presence of Zn in the coating. The Zn-substituted hydroxyapatite coating was formed by an equiaxed polycrystalline grain structure. Effect of substrate crystallinity on the structure of deposited coating is discussed. An amorphous TiO2 sublayer of 8-nm thickness was detected in the interface between the polycrystalline coating and the Ti substrate. Its appearance in the amorphous state is attributed to prior to deposition etching of the substrate and subsequent condensation of oxygen-containing species sputtered from the target. This layer contributes to the high coating-to-substrate adhesion. The major P–O vibrational modes of high intensity were detected by Raman spectroscopy. The Zn-substituted hydroxyapatite could be a material of choice when antibacterial osteoconductive coating with a possibility of withstanding mechanical stress during implantation and service is needed.

Structural, compositional, mechanical characterization and biological assessment of bovine-derived hydroxyapatite coatings reinforced with MgF{sub 2} or MgO for implants functionalization

Energy Technology Data Exchange (ETDEWEB)

Mihailescu, Natalia [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania); Stan, G.E. [National Institute of Materials Physics, Magurele RO-077125 (Romania); Duta, L. [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania); Chifiriuc, Mariana Carmen [Department of Microbiology, Faculty of Biology, Bucharest RO-060101 (Romania); Bleotu, Coralia [Stefan S. Nicolau Institute of Virology, 85 Mihai Bravu Avenue, Bucharest RO-030304 (Romania); Sopronyi, M.; Luculescu, C. [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania); Oktar, F.N. [Department of Bioengineering, Faculty of Engineering, Marmara University, Goztepe, Istanbul TR-34722 (Turkey); Advance Nanomaterials Research Laboratory, Marmara University, Goztepe, Istanbul TR-34722 (Turkey); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania)

2016-02-01

Hydroxyapatite (HA) is a consecrated biomaterial for bone reconstruction. In the form of thin films deposited by pulsed laser technologies, it can be used to cover metallic implants aiming to increase biocompatibility and osseointegration rate. HA of animal origin (bovine, BHA) reinforced with MgF{sub 2} (2 wt.%) or MgO (5 wt.%) were used for deposition of thin coatings with improved adherence, biocompatibility and antimicrobial activity. For pulsed laser deposition experiments, a KrF* (λ = 248 nm, τ{sub FWHM} ≤ 25 ns) excimer laser source was used. The deposited structures were characterized from a physical–chemical point of view by X-Ray Diffraction, Fourier Transform Infra-Red Spectroscopy, Scanning Electron Microscopy in top- and cross-view modes, Energy Dispersive X-Ray Spectroscopy and Pull-out adherence tests. The microbiological assay using the HEp-2 cell line revealed that all target materials and deposited thin films are non-cytotoxic. We conducted tests on three strains isolated from patients with dental implants failure, i.e. Microccocus sp., Enterobacter sp. and Candida albicans sp. The most significant anti-biofilm effect against Microcococcus sp. strain, at 72 h, was obtained in the presence of BHA:MgO thin films. For Enterobacter sp. strain a superior antimicrobial activity at 72 h was noticed, in respect with simple BHA or Ti control. The enhanced antimicrobial performances, correlated with good cytocompatibility and mechanical properties recommend these biomaterials as an alternative to synthetic HA for the fabrication of reliable implant coatings for dentistry and other applications. - Highlights: • Novel biological derived HA coatings fabricated by pulsed laser deposition. • Renewable resources • Reinforcement with MgF{sub 2} and MgO improves the HA coatings' bonding strength. • Significant anti-biofilm effect obtained for MgO reinforced HA films. • Alternative low cost solutions for a new generation of dental implants.

Pedicle screws with a thin hydroxyapatite coating for improving fixation at the bone-implant interface in the osteoporotic spine: experimental study in a porcine model.

Science.gov (United States)

Ohe, Makoto; Moridaira, Hiroshi; Inami, Satoshi; Takeuchi, Daisaku; Nohara, Yutaka; Taneichi, Hiroshi

2018-03-30

OBJECTIVE Instrumentation failure caused by the loosening of pedicle screws (PSs) in patients with osteoporosis is a serious problem after spinal surgery. The addition of a thin hydroxyapatite (HA) surface coating applied by using a sputtering process was reported recently to be a promising method for providing bone conduction around an implant without a significant risk of coating-layer breakage. In this study, the authors evaluated the biomechanical and histological features of the bone-implant interface (BII) of PSs with a thin HA coating in an in vivo porcine osteoporotic spine model. METHODS Three types of PSs (untreated/standard [STPS], sandblasted [BLPS], and HA-coated [HAPS] PSs) were implanted into the thoracic and lumbar spine (T9-L6) of 8 mature Clawn miniature pigs (6 ovariectomized [osteoporosis group] and 2 sham-operated [control group] pigs). The spines were harvested from the osteoporosis group at 0, 2, 4, 8, 12, or 24 weeks after PS placement and from the control group at 0 or 24 weeks. Their bone mineral density (BMD) was measured by peripheral quantitative CT. Histological evaluation of the BIIs was conducted by performing bone volume/tissue volume and bone surface/implant surface measurements. The strength of the BII was evaluated with extraction torque testing. RESULTS The BMD decreased significantly in the osteoporosis group (p < 0.01). HAPSs exhibited the greatest mean extraction peak torque at 8 weeks, and HAPSs and BLPSs exhibited significantly greater mean torque than the STPSs at 12 weeks (p < 0.05). The bone surface/implant surface ratio was significantly higher for HAPSs than for STPSs after 2 weeks (p < 0.05), and bonding between bone and the implant surface was maintained until 24 weeks with no detachment of the coating layer. In contrast, the bone volume/tissue volume ratio was significantly higher for HAPSs than for BLPSs or STPSs only at 4 weeks. CONCLUSIONS Using PSs with a thin HA coating applied using a sputtering process

Effect of thermal decomposition of hydroxyapatite on the thermoluminescent response

International Nuclear Information System (INIS)

Sandoval C, K. J.; Zarate M, J.; Lemus R, J.; Rivera M, T.

2014-08-01

In this work, a study on the thermoluminescence (Tl) induced by gamma radiation in synthetic hydroxyapatite (Hap) annealed at different temperatures obtained by the precipitation method is presented. Synthesis of hydroxyapatite Hap was carried out starting from inorganic precursors [Ca(NO 3 ) 2 ·4H 2 O and (NH 4 ) 2 HPO 4 ]. The precipitate was filtered, washed, dried and then the powder was calcined at different temperatures until the Hap decomposition. The structural and morphological characterization was carried out using both X-ray diffraction (XRD) and scanning electron microscopy (Sem) techniques. Thermoluminescent (Tl) properties of Hap powders were irradiated at different gamma radiation doses. According to X ray diffraction patterns, the tricalcium diphosphate phase (Tcp) appear when the Hap was calcined at 900 grades C. Tl glow curve showed two peaks located at around 200 and 300 grades C, respectively. Tl response as a function of gamma radiation dose was in a wide range from 25 to 100 Gy. The fading of the Tl response at 134 days after irradiation was measured. Experimental results showed that the synthetic hydroxyapatite obtained by precipitation technique may have dosimetric applications when is annealed at temperature of 900 grades C, where the Tcp phase appears and contributes to Tl response, which opens the possibility of using this biomaterials in the area of dosimetry, as they are generally used for biomedical implants. (author)

Surface modification of yttria stabilized zirconia via polydopamine inspired coating for hydroxyapatite biomineralization

Science.gov (United States)

Zain, Norhidayu Muhamad; Hussain, Rafaqat; Kadir, Mohammed Rafiq Abdul

2014-12-01

Yttria stabilized zirconia (YSZ) has been widely used as biomedical implant due to its high strength and enhanced toughening characteristics. However, YSZ is a bioinert material which constrains the formation of chemical bonds with bone tissue following implantation. Inspired by the property of mussels, the surface of YSZ ceramics was functionalized by quinone-rich polydopamine to facilitate the biomineralization of hydroxyapatite. YSZ discs were first immersed in 2 mg/mL of stirred or unstirred dopamine solution at either 25 or 37 °C. The samples were then incubated in 1.5 simulated body fluid (SBF) for 7d. The effect of coating temperature for stirred and unstirred dopamine solutions during substrate grafting was investigated on the basis of chemical compositions, wettability and biomineralization of hydroxyapatite on the YSZ functionalized surface. The results revealed that the YSZ substrate grafted at 37 °C in stirred solution of dopamine possessed significantly improved hydrophilicity (water contact angle of 44.0 ± 2.3) and apatite-mineralization ability (apatite ratio of 1.78). In summary, the coating temperature and stirring condition during grafting procedure affected the chemical compositions of the films and thus influenced the formation of apatite layer on the substrate during the biomineralization process.

Fracture of a HTR-PMI cranioplastic implant after severe TBI.

Science.gov (United States)

López González, Antonio; Pérez Borredá, Pedro; Conde Sardón, Rebeca

2015-02-01

A 13-year-old girl with a large left fronto-parietal hard-tissue replacement patient-matched implant (HTR®-PMI) cranioplasty-since she suffered from a traumatic brain injury (TBI) 6 years ago-had a new severe TBI that detached and fractured the implant as well as caused a left subdural hematoma and a large frontal contusion. The hematoma and contusion were removed and the implant was substituted by a provisional titanium mesh. To the best of our knowledge, this is the first case reported about an HTR®-PMI fracture. It is theorized that the bone ingrowth into the macroporous implants, like those of hydroxyapatite, gives strength and resistance to the implant. But in the case we describe, no macroscopic bone ingrowth was detected 6 years after implantation and the traumatic force that impacted over the cranioplasty exceeded its properties.

Direct growth of carbon nanotubes on hydroxyapatite using MPECVD

International Nuclear Information System (INIS)

Duraia, El-Shazly M.; Hannora, A.; Mansurov, Z.; Beall, Gary W.

2012-01-01

Graphical abstract: Carbon nanotubes have been grown directly on hydroxyapatite by using microwave plasma-enhanced chemical vapor deposition (MPECVD). Highlights: ► CNTs have been successfully grown directly on hydroxyapatite using MPECVD. ► Diameter distribution of the CNTs lies in the range from 30 to 70 nm. ► The HA surface is partially transformed to β-TCP during the deposition. ► Grown CNTs have good quality and I G /I D ratio lies between 1.243 and 1.774. - Abstract: For the first time carbon nanotubes (CNTs) have been successfully grown directly on hydroxyapatite (HA) by using microwave plasma enhanced chemical vapor deposition (MPECVD). Such integration has potential to capitalize on the merits of both HA and CNTs. This type of coating could be useful to improve the interface between bone and the implant. Scanning electron microscope SEM investigations show that; the surface of the CNTs is relatively clean and free of amorphous carbon. The CNTs diameters lie in the range 30–70 nm. In addition HA encapsulation by carbon was observed at a growth temperature 750 °C. Raman spectroscopy indicates that the CNTs are of high quality and the I G /I D ratio lies between 1.243 and 1.774. The changes in the X-ray diffraction (XRD) patterns give an indication that during the plasma deposition the HA-substrate surface is subjected to a temperature sufficient for partial conversion to the β-tricalcium phosphate via dehydroxylation.

Anchorage of TiO2-blasted, HA-coated, and machined implants: an experimental study with rabbits

DEFF Research Database (Denmark)

Gotfredsen, K; Wennerberg, A; Johansson, C

1995-01-01

The purpose of this study was to evaluate the histometrical and biomechanical anchorage of TiO2-blasted implants and TiO2-blasted implants coated with hydroxyapatite. The control implants were machined. Twenty-six rabbits had a total of 156 implants placed in the proximal part of the tibia. Each...... rabbit had a machined, a TiO2-blasted, and a TiO2-blasted, HA-coated implant placed in each tibia. After a healing period of 3 and 12 weeks, respectively, the implants placed in the right tibia were used for removal torque test, and the implants placed in the left tibia were used for histomorphometrical...

Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation

Energy Technology Data Exchange (ETDEWEB)

Chen, Wei [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Tian, Bo [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Lei, Yong; Ke, Qin-Fei [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Zhu, Zhen-An, E-mail: zhuzhenan2006@126.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Guo, Ya-Ping, E-mail: ypguo@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China)

2016-10-01

Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120 °C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37 °C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. - Highlights: • We prepare hydroxyapatite coatings with oriented nanoplate and nanorod arrays. • Hydroxyapatite coatings are in situ converted from bioglass coatings. • Hydroxyapatite coatings have good cytocompatibility and osteogenic differentiation. • Oriented hydroxyapatite coatings are used for orthopedic implants.

Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation

International Nuclear Information System (INIS)

Chen, Wei; Tian, Bo; Lei, Yong; Ke, Qin-Fei; Zhu, Zhen-An; Guo, Ya-Ping

2016-01-01

Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120 °C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37 °C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. - Highlights: • We prepare hydroxyapatite coatings with oriented nanoplate and nanorod arrays. • Hydroxyapatite coatings are in situ converted from bioglass coatings. • Hydroxyapatite coatings have good cytocompatibility and osteogenic differentiation. • Oriented hydroxyapatite coatings are used for orthopedic implants.

Elders with implant overdentures: a 22-year clinical report.

Science.gov (United States)

Alsabeeha, Nabeel H M

2012-09-01

To report on the long-term survival and prosthodontic maintenance of two edentulous adults with mandibular overdentures supported by hydroxyapatite (HA)-coated implants. Mandibular implant overdentures are a successful treatment option with positive impact on the quality of life of elderly edentulous adults. Long-term survival of the implants requires continued rigorous prosthodontic maintenance. Two elderly edentulous adults with mandibular overdentures supported by 2 HA-coated implants were presented for prosthodontic rehabilitation after 22 years of placement. The implants were osseo-integrated and surviving at presentation based on accepted criteria. The mandibular implant overdentures suffered recurrent loss of retention and stability. Prosthodontic treatment involving the replacement of defective attachment systems and construction of new sets of mandibular implant overdentures opposing complete maxillary dentures is presented. The long-term survival of mandibular 2-implant overdentures requires continued prosthodontic maintenance. A conservative approach in the rehabilitation of two older edentulous adults with mandibular 2-implant overdentures was described including proper selection of attachment systems. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

In vivo evaluation of the bone integration of coated poly(vinyl-alcohol) hydrogel fiber implants.

Science.gov (United States)

Moreau, David; Villain, Arthur; Bachy, Manon; Proudhon, Henry; Ku, David N; Hannouche, Didier; Petite, Hervé; Corté, Laurent

2017-08-01

Recently, it has been shown that constructs of poly(vinyl alcohol) (PVA) hydrogel fibers reproduce closely the tensile behavior of ligaments. However, the biological response to these systems has not been explored yet. Here, we report the first in vivo evaluation of these implants and focus on the integration in bone, using a rabbit model of bone tunnel healing. Implants consisted in bundles of PVA hydrogel fibers embedded in a PVA hydrogel matrix. Half of the samples were coated with a composite coating of hydroxyapatite (HA) particles embedded in PVA hydrogel. The biological integration was evaluated at 6 weeks using histology and micro-CT imaging. For all implants, a good biological tolerance and growth of new bone tissue are reported. All the implants were surrounded by a fibrous layer comparable to what was previously observed for poly(ethylene terephthalate) (PET) fibers currently used in humans for ligament reconstruction. An image analysis method is proposed to quantify the thickness of this fibrous capsule. Implants coated with HA were not significantly osteoconductive, which can be attributed to the slow dissolution of the selected hydroxyapatite. Overall, these results confirm the relevance of PVA hydrogel fibers for ligament reconstruction and adjustments are proposed to enhance its osseointegration.

Characterisation and corrosion resistance of the electrodeposited hydroxyapatite and bovine serum albumin/hydroxyapatite films on Ti-6Al-4V-1Zr alloy surface

International Nuclear Information System (INIS)

Vasilescu, C.; Drob, P.; Vasilescu, E.; Demetrescu, I.; Ionita, D.; Prodana, M.; Drob, S.I.

2011-01-01

Graphical abstract: Display Omitted Research highlights: → EIS spectra for Ti6Al4V1Zr alloy were fitted with one time constant electric equivalent circuit. → For covered alloy the equivalent circuit contains two time constants. → Resistances of films increased in time revealing the improvement of the alloy protection capacity. → Surface roughness significantly increased by apatite formation, being favourably to cell adhesion. - Abstract: A new titanium base Ti-6Al-4V-1Zr alloy covered with hydroxyapatite or bovine serum albumin/hydroxyapatite was characterized in this paper in order to be used as implant material. Following techniques were used: linear polarization, electrochemical impedance spectroscopy, scanning electronic microscopy, Fourier transform infrared spectroscopy and atomic force microscopy. For HA or BSA/HA covered alloy, the electric equivalent circuit contains two time constants (for the passive film and for coatings). The resistance of the protective films increased in time and BSA/HA coating was slightly rougher than HA coating, this situation being favourably to the cell adhesion.

Characterisation and corrosion resistance of the electrodeposited hydroxyapatite and bovine serum albumin/hydroxyapatite films on Ti-6Al-4V-1Zr alloy surface

Energy Technology Data Exchange (ETDEWEB)

Vasilescu, C.; Drob, P. [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania); Vasilescu, E., E-mail: ec_vasilescu@yahoo.co [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania); Demetrescu, I.; Ionita, D.; Prodana, M. [Politehnica University of Bucharest, Faculty of Applied Chemistry and Material Science, Str. Polizu 1-7, 011061 Bucharest (Romania); Drob, S.I. [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania)

2011-03-15

Graphical abstract: Display Omitted Research highlights: {yields} EIS spectra for Ti6Al4V1Zr alloy were fitted with one time constant electric equivalent circuit. {yields} For covered alloy the equivalent circuit contains two time constants. {yields} Resistances of films increased in time revealing the improvement of the alloy protection capacity. {yields} Surface roughness significantly increased by apatite formation, being favourably to cell adhesion. - Abstract: A new titanium base Ti-6Al-4V-1Zr alloy covered with hydroxyapatite or bovine serum albumin/hydroxyapatite was characterized in this paper in order to be used as implant material. Following techniques were used: linear polarization, electrochemical impedance spectroscopy, scanning electronic microscopy, Fourier transform infrared spectroscopy and atomic force microscopy. For HA or BSA/HA covered alloy, the electric equivalent circuit contains two time constants (for the passive film and for coatings). The resistance of the protective films increased in time and BSA/HA coating was slightly rougher than HA coating, this situation being favourably to the cell adhesion.

Development of an accommodating intra-ocular lens - In vitro prevention of re-growth of pig and rabbit lens capsule epithelial cells

NARCIS (Netherlands)

van Kooten, Theo G.; Koopmans, Steven; Terwee, Thom; Norrby, Sverker; Hooymans, J. M. M.; Busscher, Henk J.

2006-01-01

Cataract surgery is routinely performed to replace the clouded lens by a rigid polymeric intra-ocular lens unable to accommodate. By implanting a silicone gel into an intact capsular bag the accommodating properties of the natural lens can be maintained or enhanced. The implantation success of

Synthesis, bioactivity and zeta potential investigations of chlorine and fluorine substituted hydroxyapatite.

Science.gov (United States)

Fahami, Abbas; Beall, Gary W; Betancourt, Tania

2016-02-01

Chlorine and fluorine substituted hydroxyapatites (HA-Cl-F) with different degrees of ion replacement were successfully prepared by the one step mechanochemical activation method. X-ray diffraction (XRD) and FT-IR spectra indicated that substitution of these anions in milled powders resulted in the formation of pure hydroxyapatite phase except for the small observed change in the lattice parameters and unit cell volumes of the resultant hydroxyapatite. Microscopic observations showed that the milled product had a cluster-like structure made up of polygonal and spherical particles with an average particle size of approximately ranged from 20±5 to 70±5nm. The zeta potential of milled samples was performed at three different pH (5, 7.4, and 9). The obtained zeta potential values were negative for all three pH values. Negative zeta potential was described to favor osseointegration, apatite nucleation, and bone regeneration. The bioactivity of samples was investigated on sintered pellets soaked in simulated body fluid (SBF) solution and apatite crystals formed on the surface of the pellets after being incubated for 14days. Zeta potential analysis and bioactivity experiment suggested that HA-Cl-F will lead to the formation of new apatite particles and therefore be a potential implant material. Copyright © 2015 Elsevier B.V. All rights reserved.

Substitution effects of a carbonated hydroxyapatite biomaterial against intoxication chloride nickel-exposed rats.

Science.gov (United States)

Boulila, Salha; Elfeki, Abdelfattah; Oudadesse, Hassane; Elfeki, Hafed

2015-03-01

This study aimed to investigate the potential effects of a synthetic apatite (carbonated hydroxyapatite) on the detoxification of a group of male "Wistar" rats exposed to nickel chloride. Toxicity was evaluated by rats' bioassay of nickel chloride. Wistar rats received this metal daily by gavage for seven days (4 mg/ml nickel chloride/200 g body weight, BW). To detoxify this organism, a subcutaneous implantation of the apatite is made. The results revealed that exposure to nickel induced oxidative stress, disorders in the balances of ferric phosphocalcic, renal failures, liver toxicity and significant increase in nickel rates in the bones of intoxicated rats. The application of the carbonated hydroxyapatite presented in this study restored those disorders back to normal. The synthetic apatite protected the rats against the toxic effects of nickel by lowering the levels of lipid peroxidation markers and improving the activities of defense enzymes. It also amended ferric and phosphocalcic equilibriums, protected liver and kidney functions and reduced the nickel rate in the bones of the rats. Overall, the results provided strong support for the protective role of carbonated hydroxyapatite in the detoxification of rats exposed to nickel. Those beneficial effects were further confirmed by physico-chemical characterization (X-ray diffraction and infrared spectroscopy), which revealed its property of anionic and cationic substitution, thus supporting its promising candidacy for future biomedical application. The hydroxyapatite is an effective biomaterial to solve health problems, particularly detoxification against metals (nickel).

Synthesis, bioactivity and zeta potential investigations of chlorine and fluorine substituted hydroxyapatite

International Nuclear Information System (INIS)

Fahami, Abbas; Beall, Gary W.; Betancourt, Tania

2016-01-01

Chlorine and fluorine substituted hydroxyapatites (HA-Cl–F) with different degrees of ion replacement were successfully prepared by the one step mechanochemical activation method. X-ray diffraction (XRD) and FT-IR spectra indicated that substitution of these anions in milled powders resulted in the formation of pure hydroxyapatite phase except for the small observed change in the lattice parameters and unit cell volumes of the resultant hydroxyapatite. Microscopic observations showed that the milled product had a cluster-like structure made up of polygonal and spherical particles with an average particle size of approximately ranged from 20 ± 5 to 70 ± 5 nm. The zeta potential of milled samples was performed at three different pH (5, 7.4, and 9). The obtained zeta potential values were negative for all three pH values. Negative zeta potential was described to favor osseointegration, apatite nucleation, and bone regeneration. The bioactivity of samples was investigated on sintered pellets soaked in simulated body fluid (SBF) solution and apatite crystals formed on the surface of the pellets after being incubated for 14 days. Zeta potential analysis and bioactivity experiment suggested that HA-Cl–F will lead to the formation of new apatite particles and therefore be a potential implant material. - Highlights: • Cl"− and F"− substituted hydroxyapatite was synthesized by mechanochemical process. • Structural features were influenced strongly by incorporation of different ions. • Microscopic observations showed a mean particle size of around 20 ± 5 to 70 ± 5 nm. • The bioactivity properties indicated that apatite was successfully formed.

Synthesis, bioactivity and zeta potential investigations of chlorine and fluorine substituted hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

Fahami, Abbas, E-mail: fahami@txstate.edu [Materials Science, Engineering and Commercialization Program, Texas State University, San Marcos, TX 78666 (United States); Beall, Gary W. [Department of Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX 78666 (United States); Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Betancourt, Tania [Materials Science, Engineering and Commercialization Program, Texas State University, San Marcos, TX 78666 (United States); Department of Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX 78666 (United States)

2016-02-01

Chlorine and fluorine substituted hydroxyapatites (HA-Cl–F) with different degrees of ion replacement were successfully prepared by the one step mechanochemical activation method. X-ray diffraction (XRD) and FT-IR spectra indicated that substitution of these anions in milled powders resulted in the formation of pure hydroxyapatite phase except for the small observed change in the lattice parameters and unit cell volumes of the resultant hydroxyapatite. Microscopic observations showed that the milled product had a cluster-like structure made up of polygonal and spherical particles with an average particle size of approximately ranged from 20 ± 5 to 70 ± 5 nm. The zeta potential of milled samples was performed at three different pH (5, 7.4, and 9). The obtained zeta potential values were negative for all three pH values. Negative zeta potential was described to favor osseointegration, apatite nucleation, and bone regeneration. The bioactivity of samples was investigated on sintered pellets soaked in simulated body fluid (SBF) solution and apatite crystals formed on the surface of the pellets after being incubated for 14 days. Zeta potential analysis and bioactivity experiment suggested that HA-Cl–F will lead to the formation of new apatite particles and therefore be a potential implant material. - Highlights: • Cl{sup −} and F{sup −} substituted hydroxyapatite was synthesized by mechanochemical process. • Structural features were influenced strongly by incorporation of different ions. • Microscopic observations showed a mean particle size of around 20 ± 5 to 70 ± 5 nm. • The bioactivity properties indicated that apatite was successfully formed.

A Multidisciplinary Approach for Rehabilitation of Enucleated Sockets: Ocular Implants with Custom Ocular Prosthesis.

Science.gov (United States)

Choudhury, Minati; Banu, Fathima; Natarajan, Shanmuganathan; Kumar, Anand; Tv, Padmanabhan

2018-02-16

Interdisciplinary prosthodontics goes beyond our imagination into fields that have a direct effect on our total body health and quality of life. Removal of an eye has a detrimental effect on the psychology of the patient. Enucleation involves removal of the eyeball proper and leads to an enophthalmic socket with a shrunken eye, which has a crippling effect on patient's emotional and social life. Custom-made eye prosthesis simulates the characteristics of the companion eye and helps in restoring the normal facial appearance. Restoration of saccadic eye movements occurring during speech is desirable because this greatly contributes to a normal facial expression. This can be achieved by an orbital implant, which helps in orbital volume replacement and restoration of prosthesis movement and comfort. This article describes prosthodontic rehabilitation of enucleated eye sockets with orbital implants for two patients.

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

International Nuclear Information System (INIS)

Parente, P.; Savoini, B.; Ferrari, B.; Monge, M.A.; Pareja, R.; Sanchez-Herencia, A.J.

2013-01-01

The capability of the colloidal method to produce yttria (Y 2 O 3 ) dispersed hydroxyapatite (HA) has been investigated as an alternative method to the conventional method of mechanical mixing and sintering for developing HA-based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce HA materials with highly dispersed Y 2 O 3 has been applied, and the effect of 10 wt.% Y 2 O 3 addition to HA investigated by thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy. These measurements evidence a remarkable effect of this Y 2 O 3 addition on decomposition mechanisms of synthetic HA. Results show that incorporation of Y 2 O 3 as dispersed second phase is beneficial because it hinders the decomposition mechanisms of HA into calcium phosphates. This retardation will allow the control of the sintering conditions for developing HA implants with improved properties. Besides, substitution of Ca 2+ with Y 3+ ions appears to promote the formation of OH − vacancies, which could improve the conductive properties of HA favorable to osseointegration. - Highlights: ► We reveal the influence of Y 2 O 3 on thermal stability of hydroxyapatite. ► Incorporation of Y 2 O 3 delays decomposition of hydroxyapatite to calcium phosphates. ► Addition of Y 2 O 3 enables sintering conditions more favorable to the densification.

Ostrich eggshell as calcium source for the synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc

International Nuclear Information System (INIS)

Ferreira, J.R.M.; Louro, L.H.L.; Costa, A.M.; Silva, M.H. Prado da; Campos, J.B. de

2016-01-01

In the present study, hydroxyapatite and Zn-substituted hydroxyapatite powders were synthesized using ostrich eggshell as a calcium source. The samples were analyzed by scanning electron microscopy with field emission gun, and X-ray diffraction (XRD) to identify the present phases, and X-ray fluorescence spectroscopy for quantitative chemical analysis of the synthesized and heat treated powders. The Fourier transform infrared spectroscopy technique was used before and after heat treatments at 700, 900 and 1100 °C in order to identify the functional groups present, as an additional technique to the XRD analysis. The results presented in this study represent a promising method for synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc, since the results showed no undesirable phases or impurities in the produced powders. It was observed that Zn-substituted hydroxyapatite showed higher thermal stability, when compared to pure hydroxyapatite. (author)

Ostrich eggshell as calcium source for the synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc

Energy Technology Data Exchange (ETDEWEB)

Ferreira, J.R.M.; Louro, L.H.L.; Costa, A.M.; Silva, M.H. Prado da [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Campos, J.B. de, E-mail: josericardo@r-crio.com, E-mail: louro@ime.eb.br, E-mail: andrea@r-crio.com, E-mail: brantjose@gmail.com, E-mail: marceloprado@ime.eb.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

2016-10-15

In the present study, hydroxyapatite and Zn-substituted hydroxyapatite powders were synthesized using ostrich eggshell as a calcium source. The samples were analyzed by scanning electron microscopy with field emission gun, and X-ray diffraction (XRD) to identify the present phases, and X-ray fluorescence spectroscopy for quantitative chemical analysis of the synthesized and heat treated powders. The Fourier transform infrared spectroscopy technique was used before and after heat treatments at 700, 900 and 1100 °C in order to identify the functional groups present, as an additional technique to the XRD analysis. The results presented in this study represent a promising method for synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc, since the results showed no undesirable phases or impurities in the produced powders. It was observed that Zn-substituted hydroxyapatite showed higher thermal stability, when compared to pure hydroxyapatite. (author)

Retention of albumin labelled with I-125 in the bio mineral hydroxyapatite; Retencion de albumina marcada con I-125 en el biomineral hidroxiapatita

Energy Technology Data Exchange (ETDEWEB)

Badillo A, V.E.; Bugarin C, A. [UAZ, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2003-07-01

The demands of materials for the health in the entire world, especially of the odontological and traumatological sectors make every time to be but studied the hydroxyapatite (HAP) and their biocompatibility with the alive beings. The hydroxyapatite is considered as one of the inorganic exchangers by excellence, for what the fixation of ions and molecules have been widely studied and at the moment it is one of the materials of greater acceptance like implant. The surface of the material of implant is in intimate contact with the live tissue and its biocompatibility is determined in great measure by those surface properties of the bio material, which have a direct effect in the cellular response of the material. After administering the implant, the proteins are immediately adsorbed in the surface of the bio mineral. Specifically, the proteins of the blood are considered as key pieces to determine the acceptance of implants in alive beings. The adsorption of proteins it depends on the physicochemical properties of the material as well as of the environment composition. The surface properties of the HAP are relevant in the adsorption mechanisms of the proteins. In this work, it is reported the adsorption of the labelled with I-125 albumin protein and in function of two important physicochemical parameters: the pH value of the of the solution and the chemical nature of the solution; to see the influence of this last, its were studied three electrolytes NaF, NaCl and NaH{sub 2}PO{sub 4}. The existence of the active sites of hydroxyapatite surface, it is key piece in the interpretation of the fixation of the albumin protein in function also of their acid-base properties. (Author)

Effect of thermal decomposition of hydroxyapatite on the thermoluminescent response

Energy Technology Data Exchange (ETDEWEB)

Sandoval C, K. J.; Zarate M, J.; Lemus R, J. [Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Investigaciones Metalurgicas, Ciudad Universitaria, Edificio U, 58060 Morelia, Michoacan (Mexico); Rivera M, T., E-mail: karlasandovalc@gmail.com [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico)

2014-08-15

In this work, a study on the thermoluminescence (Tl) induced by gamma radiation in synthetic hydroxyapatite (Hap) annealed at different temperatures obtained by the precipitation method is presented. Synthesis of hydroxyapatite Hap was carried out starting from inorganic precursors [Ca(NO{sub 3}){sub 2}·4H{sub 2}O and (NH{sub 4}){sub 2}HPO{sub 4}]. The precipitate was filtered, washed, dried and then the powder was calcined at different temperatures until the Hap decomposition. The structural and morphological characterization was carried out using both X-ray diffraction (XRD) and scanning electron microscopy (Sem) techniques. Thermoluminescent (Tl) properties of Hap powders were irradiated at different gamma radiation doses. According to X ray diffraction patterns, the tricalcium diphosphate phase (Tcp) appear when the Hap was calcined at 900 grades C. Tl glow curve showed two peaks located at around 200 and 300 grades C, respectively. Tl response as a function of gamma radiation dose was in a wide range from 25 to 100 Gy. The fading of the Tl response at 134 days after irradiation was measured. Experimental results showed that the synthetic hydroxyapatite obtained by precipitation technique may have dosimetric applications when is annealed at temperature of 900 grades C, where the Tcp phase appears and contributes to Tl response, which opens the possibility of using this biomaterials in the area of dosimetry, as they are generally used for biomedical implants. (author)

Penetrating ocular trauma from trampoline spring.

Science.gov (United States)

Spokes, David; Siddiqui, Salina; Vize, Colin

2010-02-01

The case is presented of a 12-year old boy who sustained severe penetrating ocular trauma while playing on a domestic trampoline. A main spring broke under tension and the hook had struck the eye at high velocity and penetrated the sclera. Primary repair was undertaken but on review it became apparent the eye could not be salvaged. Evisceration was carried out and an orbital implant was placed. Post-operative cosmesis is acceptable. This type of injury has not been reported before. Adult supervision of children on trampolines is recommended to minimise the chance of serious injury.

Novel hydroxyapatite biomaterial covalently linked to raloxifene.

Science.gov (United States)

Meme, L; Santarelli, A; Marzo, G; Emanuelli, M; Nocini, P F; Bertossi, D; Putignano, A; Dioguardi, M; Lo Muzio, L; Bambini, F

2014-01-01

Since raloxifene, a drug used in osteoporosis therapy, inhibits osteoclast, but not osteoblast functions, it has been suggested to improve recovery during implant surgery. The present paper describes an effective method to link raloxifene, through a covalent bond, to a nano-Hydroxyapatite-based biomaterial by interfacing with (3-aminopropyl)-Triethoxysilane as assessed by Infra Red-Fourier Transformed (IR-FT) spectroscopy and Scanning Electron Microscope (SEM). To evaluate the safety of this modified new material, the vitality of osteoblast-like cells cultured with the new biomaterial was then investigated. Raloxifene-conjugated HAbiomaterial has been shown to be a safe material easy to obtain which could be an interesting starting point for the use of a new functional biomaterial suitable in bone regeneration procedures.

Facoemulsificação, vitrectomia via pars plana e implante de lente intra-ocular em olhos com retinopatia diabética proliferativa Phacoemulsification, pars plana vitrectomy and intraocular lens implant in eyes with proliferative diabetic retinopathy

Directory of Open Access Journals (Sweden)

Armando Belfort Mattos

2004-06-01

Full Text Available OBJETIVO: Avaliar a viabilidade da técnica de facoemulsificação para a extração da catarata com implante de lente intra-ocular combinada à vitrectomia via pars plana em olhos com retinopatia diabética proliferativa, em um único procedimento cirúrgico. MÉTODOS: Foram revisados os prontuários de 47 pacientes (53 olhos com retinopatia diabética proliferativa e catarata que foram submetidos ao procedimento combinado de vitrectomia via pars plana, facoemulsificação e implante de lente intra-ocular no mesmo ato cirúrgico, entre janeiro de 1991 e setembro de 1998 no Bascom Palmer Eye Institute, hospital de olhos filiado à Universidade de Miami. O estudo foi realizado em conjunto com a Universidade Federal de São Paulo. Participaram do estudo 43 olhos de 40 pacientes. RESULTADOS: O tempo de seguimento variou de três a 60 meses com média de 20 meses. A idade dos pacientes variou de 37 a 77 anos com média de 59 anos. A acuidade visual melhorou duas linhas ou mais em relação ao pré-operatório em 26 (60,4% olhos, permaneceu a mesma em 9 (20,9% e piorou em 8 (18,6%. Em (23,2% 10 olhos a acuidade visual aumentou para 20/40. O teste estatístico chamado de "teste do sinal" mostrou-se estatisticamente significante na melhora da acuidade visual final. A complicação mais observada foi a hemorragia vítrea recorrente, ocorrendo em 12 (27,9% olhos, seguida pela inflamação transitória da câmara anterior em 9 olhos (20,9%. Complicações intra-operatórias relacionadas à extração do cristalino foram raras. No pós-operatório observaram-se captura da lente intra-ocular em 2 (4,6 % olhos e lente intra-ocular subluxada em 1 (2,3% olho. CONCLUSÕES: A cirurgia combinada de facoemulsificação, implante de lente intra-ocular e vitrectomia via pars plana em olhos com retinopatia diabética é procedimento bem tolerado e geralmente apresenta bons resultados com relação à acuidade visual. Um único procedimento para remover a catarata e

Direct growth of carbon nanotubes on hydroxyapatite using MPECVD

Energy Technology Data Exchange (ETDEWEB)

Duraia, El-Shazly M., E-mail: duraia_physics@yahoo.com [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Al-Farbi Kazakh National University, Almaty (Kazakhstan); Institute of Physics and Technology, Almaty (Kazakhstan); Texas State University-San Marcos, Department of Chemistry and Biochemistry, 601 University Dr., San Marcos, TX 78666 (United States); Hannora, A. [Suez Canal University, Faculty of Petroleum and Mining Engineering (Egypt); Mansurov, Z. [Al-Farbi Kazakh National University, Almaty (Kazakhstan); Beall, Gary W. [Texas State University-San Marcos, Department of Chemistry and Biochemistry, 601 University Dr., San Marcos, TX 78666 (United States)

2012-01-16

Graphical abstract: Carbon nanotubes have been grown directly on hydroxyapatite by using microwave plasma-enhanced chemical vapor deposition (MPECVD). Highlights: Black-Right-Pointing-Pointer CNTs have been successfully grown directly on hydroxyapatite using MPECVD. Black-Right-Pointing-Pointer Diameter distribution of the CNTs lies in the range from 30 to 70 nm. Black-Right-Pointing-Pointer The HA surface is partially transformed to {beta}-TCP during the deposition. Black-Right-Pointing-Pointer Grown CNTs have good quality and I{sub G}/I{sub D} ratio lies between 1.243 and 1.774. - Abstract: For the first time carbon nanotubes (CNTs) have been successfully grown directly on hydroxyapatite (HA) by using microwave plasma enhanced chemical vapor deposition (MPECVD). Such integration has potential to capitalize on the merits of both HA and CNTs. This type of coating could be useful to improve the interface between bone and the implant. Scanning electron microscope SEM investigations show that; the surface of the CNTs is relatively clean and free of amorphous carbon. The CNTs diameters lie in the range 30-70 nm. In addition HA encapsulation by carbon was observed at a growth temperature 750 Degree-Sign C. Raman spectroscopy indicates that the CNTs are of high quality and the I{sub G}/I{sub D} ratio lies between 1.243 and 1.774. The changes in the X-ray diffraction (XRD) patterns give an indication that during the plasma deposition the HA-substrate surface is subjected to a temperature sufficient for partial conversion to the {beta}-tricalcium phosphate via dehydroxylation.

[Osseontegration of trial implants of carbon fiber reinforced plastics].

Science.gov (United States)

Schreiner, U; Schwarz, M; Scheller, G; Schroeder-Boersch, H; Jani, L

2000-01-01

To what extent are carbon fibre-reinforced plastics (CFRP) suitable as an osseous integration surface for implants? CFRP test implants having a plexus-structured, rhombus-structured, and plexus-structured, hydroxyapatite surface were implanted in the femura of mini-plgs. Exposure time lasted 12 weeks. The implants were subjected to a macroradiological, a histological-histomorphometrical, and a fluorescence-microscopical evaluation. One half of the uncoated, plexus-structured implants were not osteointegrated, the other half displayed an osteointegration rate of 11.8% in the spongy area and 29.8% in the cortex layer. The HA-coated test implants showed an osteointegration of 29.5% in the spongiosa and 56.8% in the cortex layer. The rhombus-structured test implants had an osteointegration of 29.2% (spongiosa) and 46.2% (cortex layer). Compared to the osteointegration of metallic, especially titanium surfaces the CFRP surfaces tested by us fared worse, especially the uncoated, plexus-structured surfaces. For this reason we view very critically the use of carbon-fibre reinforced plastics together with the surfaces tested by us as osteointegrating surfaces.

Ostrich eggshell as calcium source for the synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc

Directory of Open Access Journals (Sweden)

J. R. M. Ferreira

Full Text Available Abstract In the present study, hydroxyapatite and Zn-substituted hydroxyapatite powders were synthesized using ostrich eggshell as a calcium source. The samples were analyzed by scanning electron microscopy with field emission gun, and X-ray diffraction (XRD to identify the present phases, and X-ray fluorescence spectroscopy for quantitative chemical analysis of the synthesized and heat treated powders. The Fourier transform infrared spectroscopy technique was used before and after heat treatments at 700, 900 and 1100 °C in order to identify the functional groups present, as an additional technique to the XRD analysis. The results presented in this study represent a promising method for synthesis of hydroxyapatite and hydroxyapatite partially substituted with zinc, since the results showed no undesirable phases or impurities in the produced powders. It was observed that Zn-substituted hydroxyapatite showed higher thermal stability, when compared to pure hydroxyapatite.

Synthesis and Characterization of Hydroxyapatite/Fullerenol Nanocomposites.

Science.gov (United States)

Djordjevic, Aleksandar; Ignjatovic, Nenad; Seke, Mariana; Jovic, Danica; Uskokovic, Dragan; Rakocevic, Zlatko

2015-02-01

Fullerenols are polyhydroxylated, water soluble derivatives of fullerene C60, with potential application in medicine as diagnostic agents, antioxidants or nano drug carriers. This paper describes synthesis and physical characterization of a new nanocomposite hydroxyapatite/fullerenol. Surface of the nanocomposite hydroxyapatite/fullerenol is inhomogeneous with the diameter of the particles in the range from 100 nm to 350 nm. The ζ potential of this nanocomposite is ten times lower when compared to hydroxyapatite. Surface phosphate groups of hydroxyapatite are prone to forming hydrogen bonds, when in close contact with hydroxyl groups, which could lead to formation of hydrogen bonds between hydroxyapatite and hydroxyl groups of fullerenol. The surface of hydroxyapatite particles (-2.5 mV) was modified by fullerenol particles, as confirmed by the obtained ζ potential value of the nanocomposite biomaterial hydroxyapatite/fullerenol (-25.0 mV). Keywords: Hydroxyapatite, Fullerenol, Nanocomposite, Surface Analysis.

Incorporating catechol into electroactive polypyrrole nanowires on titanium to promote hydroxyapatite formation

Directory of Open Access Journals (Sweden)

Zhengao Wang

2018-03-01

Full Text Available To improve the osteointegration property of biomedical titanium, nano-architectured electroactive coating was synthesized through the electrochemical polymerization of dopamine and pyrrole. The highly binding affinity of Ca2+ to the catechol moiety of doped dopamine enabled efficient interaction between polypyrrole/polydopamine nanowires and mineral ions. The results indicate that the PPy/PDA nanowires preserved its efficient electro-activity and accelerated the hydroxyapatite deposition in a simulated body fluid. The PPy/PDA nanowires coating could be applied to promote the osteointegration of titanium implant.

Synthesis and Antimicrobial Activity of a Silver-Hydroxyapatite Nanocomposite

Directory of Open Access Journals (Sweden)

Marcos Díaz

2009-01-01

Full Text Available A silver-hydroxyapatite nanocomposite has been obtained by a colloidal chemical route and subsequent reduction process in H2/Ar atmosphere at 350∘C. This material has been characterized by TEM, XRD, and UV-Visible spectroscopy, showing the silver nanoparticles (∼65 nm supported onto the HA particles (∼130 nm surface without a high degree of agglomeration. The bactericidal effect against common Gram-positive and Gram-negative bacteria has been also investigated. The results indicated a high antimicrobial activity for Staphylococcus aureus, Pneumococcus and Escherichia coli, so this material can be a promising antimicrobial biomaterial for implant and reconstructive surgery applications.

Investigation of the histology and interfacial bonding between carbonated hydroxyapatite cement and bone

International Nuclear Information System (INIS)

Mao Keya; Hao Libo; Tang Peifu; Wang Zheng; Wen Ning; Du Mingkui; Wang Jifang; Wang Yan; Yang Yun; Li Jiangtao

2009-01-01

An ideal bone implant should facilitate the formation of a new bone layer as an osteo-integrated interface between bone and the implanted biomaterials. In the present work, the interface between carbonated hydroxyapatite (CHA) cement and bone was evaluated by interfacial bonding strength measurements and histological characterizations. CHA cement was implanted into a mongrel dog's femoral supracondylar and below the tibial plateau area, and was then tested ex vivo by, respectively, detaching and pullout experiments. Polymethylmethacrylate (PMMA) was used as a control. CHA cement could be directly injected and solidified in situ to repair bone defects. Histology results showed that CHA bonded with bone through gradual remodeling and was replaced by new bone tissue, which is an attribute for excellent biocompatibility. The interfacial bonding strength increased with implantation time. After 16 weeks implantation, the measured detaching force and the pullout force between CHA and bone were 281 ± 16 N and 512.5 ± 14.5 N, respectively. These values were several times higher compared to 5 days implantation. In contrast, the control showed a fibrous microstructure between PMMA and bone, and the detaching force and the pullout force decreased with implantation time. The results strongly suggest that CHA can form a better osteo-integrated interface compared to PMMA, and could be used as an ideal biomaterial for bone defect repair.

A Bone Graft Substitutes Hydroxyapatite Coated Gentamycin (Bonigent) As Drug Delivery System

International Nuclear Information System (INIS)

Rusnah Mustaffa; Fauziah Othman; Asmah Rahmat; Mohd Reusmaazran Yusof; Shaaban Kasim; Narimah Abu Baka; Nasani Nasrul

2014-01-01

Porous hydroxyapatite coated with antibiotic gentamycin for drug delivery system is namely Bonigent. In this product, antibiotic (gentamycin) is coated into the scaffolds HA porous and Would then be released slowly into the bone tissue upon implantation, this way would increase drug penetration, thus avoiding systemic infection, preventing the formation of biofilm and improved healing. When a foreign material (implants or scaffolds of bone graft substitutes) is introduced into the body, there would be normally formation of biofilm that can lead to systemic infection and cause device failure. Surgeon will use antibiotic such as gentamycin to avoid these effects. The purpose of this project is to investigate the feasibility of fabricating a drug delivery system (DDS) that serves dual functions, to combating biofilms and to enhance bone in growths. We also successfully producing a scaffold HA bone graft substitutes incorporated with antibiotic gentamycin to combating bio-film and prevent the failure medical device implant for healthy and human nation. Bone graft substitutes into porous scaffolds suitable for drug delivery; loading the scaffolds with gentamycin; and study release rate in vivo were studied. Porous bone grafts substitutes are coated with antibiotic gentamycin by immerse technique. In order to limit biofilm formation, biomaterials loaded with suitable antibiotics can be used as a preventative measure. The biomaterials hydroxyapatite (HA) is an osteoconductive space filler and is produced locally by Malaysian Nuclear Agency. Porous HA and HA/ TCP has the potential to be used as synthetic bone graft materials because it is bioactive and biocompatible with bone tissues. Development of a product as bone graft substitute (BGS) with special ability of delivering drug (gentamycin) to bone tissue for better and more effective healing process. Characterization of the physical analysis, porosity, surface morphology by Scanning Electron Microscopy Analysis (SEM) and

Electrophoretic deposition of composite hydroxyapatite-chitosan coatings

International Nuclear Information System (INIS)

Pang Xin; Zhitomirsky, Igor

2007-01-01

Cathodic electrophoretic deposition has been utilized for the fabrication of composite hydroxyapatite-chitosan coatings on 316L stainless steel substrates. The addition of chitosan to the hydroxyapatite suspensions promoted the electrophoretic deposition of the hydroxyapatite nanoparticles and resulted in the formation of composite coatings. The obtained coatings were investigated by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, potentiodynamic polarization measurements, and electrochemical impedance spectroscopy. It was shown that the deposit composition can be changed by a variation of the chitosan or hydroxyapatite concentration in the solutions. Experimental conditions were developed for the fabrication of hydroxyapatite-chitosan nanocomposites containing 40.9-89.8 wt.% hydroxyapatite. The method enabled the formation of adherent and uniform coatings of thicknesses up to 60 μm. X-ray studies revealed that the preferred orientation of the hydroxyapatite nanoparticles in the chitosan matrix increases with decreasing hydroxyapatite content in the composite coatings. The obtained coatings provided the corrosion protection for the 316L stainless steel substrates

Application of fluoridated hydroxyapatite thin film coatings using KrF pulsed laser deposition.

Science.gov (United States)

Hashimoto, Yoshiya; Ueda, Mamoru; Kohiga, Yu; Imura, Kazuki; Hontsu, Shigeki

2018-06-08

Fluoridated hydroxyapatite (FHA) was investigated for application as an implant coating for titanium bone substitute materials in dental implants. A KrF pulsed excimer deposition technique was used for film preparation on a titanium plate. The compacts were ablated by laser irradiation at an energy density of 1 J/cm 2 on an area 1×1 mm 2 with the substrate at room temparature. Energydispersive spectrometric analysis of the FHA film revealed peaks of fluorine in addition to calcium and phosphorus. X-ray diffraction revealed the presence of crystalline FHA on the FHA film after a 10 h post annealing treatment at 450°C. The FHA film coating exhibited significant dissolution resistance to sodium phosphate buffer for up to 21 days, and favorable cell attachment of human mesenchymal stem cells compared with HA film. The results of this study suggest that FHA coatings are suitable for real-world implantation applications.

Composite synthetic hydroxyapatite 30%, in two physical states, as dermal filler

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Rodrigo Viana Sepúlveda

2013-08-01

Full Text Available The aim of this study was to evaluate the response to the implantation of synthetic hydroxyapatite 30% (HAP-91® in different physical states as dermal filler. Eighteen New Zealand rabbits were used, distributed randomly into two equal groups and then divided into three groups according to the postoperative period at 8, 21 and 49 days. One mL of HAP-91®, fluid and viscous, was implanted in the subcutaneous tissue, 1 cm proximal to the cranial crest of the right scapula. The thickness of the skin was measured before and after implantation and for the following 15 days. Pain sensitivity assessment was conducted, assigning the following scores: 0 - when the animal allowed the touch of the implant area and expressed no signs of pain; 1 - when the animal allowed the touch, but pain reaction occurred, like increase of the respiratory rate or attempt to escape; 2 - when the animal did not allow the touch to the implanted area. At 8, 21 and 49 days, biopsy of the implanted area was performed. No difference was observed between the thickness of the skin (p>0.05 and all animals received a score 0 for soreness. Histological analysis did not reveal any obvious inflammatory process, showing a predominance of mononuclear cells in samples of eight days and tissue organization around the biomaterial with a tendency to encapsulation. The results indicate that HAP-91®, both viscous and fluid, is biocompatible and suitable for dermal filling.

Basic research on maxillofacial implants

International Nuclear Information System (INIS)

Matsui, Yoshiro

2001-01-01

Osseointegrated implants have begun to be used not only in general practice in dentistry but also in various clinical situations in the maxillofacial region. The process has yielded three problems: the spread of application, new materials and diagnostic methods, and management for difficult situations. This paper presents basic data and clinical guidelines for new applications, it investigates the characteristics of the materials and the usefulness of a new diagnostic method, and it studies effective techniques for difficult cases. The results obtained are as follows: Investigations into the spreading application. The lateral and superior orbital rim have sufficient bone thickness and width for the implant body to be placed. Osseointegrated implants, especially by the fixed bridge technique, are not recommended in the craniofacial bone and jaws of young children. Implant placement into bone after/before irradiation must be performed in consideration of impaired osteogenesis, the decrease of trabecular bone, and the time interval between implantation and irradiation. Investigations into materials and diagnostic methods. Hydroxyapatite-coated and titanium implants should be selected according to the characteristics of the materials. A dental simulating soft may also be applicable in the craniofacial region. Investigations into the management of difficult cases. Hyperbaric oxygen therapy (HBO), bone morphogenetic protein (BMP), and tissue engineering should be useful for improving the quality and increasing the quantity of bone where implants are placed. Soft tissue around implants placed in the reconstructed area should be replaced with mucosal tissue. The data obtained here should be useful for increasing the efficiency of osseointegrated implants, but further basic research is required in the future. (author)

Basic research on maxillofacial implants

Energy Technology Data Exchange (ETDEWEB)

Matsui, Yoshiro [Showa Univ., Tokyo (Japan). School of Dentistry

2001-11-01

Osseointegrated implants have begun to be used not only in general practice in dentistry but also in various clinical situations in the maxillofacial region. The process has yielded three problems: the spread of application, new materials and diagnostic methods, and management for difficult situations. This paper presents basic data and clinical guidelines for new applications, it investigates the characteristics of the materials and the usefulness of a new diagnostic method, and it studies effective techniques for difficult cases. The results obtained are as follows: Investigations into the spreading application. The lateral and superior orbital rim have sufficient bone thickness and width for the implant body to be placed. Osseointegrated implants, especially by the fixed bridge technique, are not recommended in the craniofacial bone and jaws of young children. Implant placement into bone after/before irradiation must be performed in consideration of impaired osteogenesis, the decrease of trabecular bone, and the time interval between implantation and irradiation. Investigations into materials and diagnostic methods. Hydroxyapatite-coated and titanium implants should be selected according to the characteristics of the materials. A dental simulating soft may also be applicable in the craniofacial region. Investigations into the management of difficult cases. Hyperbaric oxygen therapy (HBO), bone morphogenetic protein (BMP), and tissue engineering should be useful for improving the quality and increasing the quantity of bone where implants are placed. Soft tissue around implants placed in the reconstructed area should be replaced with mucosal tissue. The data obtained here should be useful for increasing the efficiency of osseointegrated implants, but further basic research is required in the future. (author)

Qualitative evaluation of titanium implant integration into bone by diffraction enhanced imaging.

Science.gov (United States)

Wagner, A; Sachse, A; Keller, M; Aurich, M; Wetzel, W-D; Hortschansky, P; Schmuck, K; Lohmann, M; Reime, B; Metge, J; Arfelli, F; Menk, R; Rigon, L; Muehleman, C; Bravin, A; Coan, P; Mollenhauer, J

2006-03-07

Diffraction enhanced imaging (DEI) uses refraction of x-rays at edges, which allows pronounced visualization of material borders and rejects scattering which often obscures edges and blurs images. Here, the first evidence is presented that, using DEI, a destruction-free evaluation of the quality of integration of metal implants into bone is possible. Experiments were performed in rabbits and sheep with model implants to investigate the option for DEI as a tool in implant research. The results obtained from DEI were compared to conventional histology obtained from the specimens. DE images allow the identification of the quality of ingrowth of bone into the hydroxyapatite layer of the implant. Incomplete integration of the implant with a remaining gap of less than 0.3 mm caused the presence of a highly refractive edge at the implant/bone border. In contrast, implants with bone fully grown onto the surface did not display a refractive signal. Therefore, the refractive signal could be utilized to diagnose implant healing and/or loosening.

Qualitative evaluation of titanium implant integration into bone by diffraction enhanced imaging

Energy Technology Data Exchange (ETDEWEB)

Wagner, A [Department of Orthopaedics of the University of Jena at the Waldkrankenhaus ' Rudolf Elle' , Jena (Germany); Sachse, A [Department of Orthopaedics of the University of Jena at the Waldkrankenhaus ' Rudolf Elle' , Jena (Germany); Keller, M [Department of Orthopaedics of the University of Jena at the Waldkrankenhaus ' Rudolf Elle' , Jena (Germany); Aurich, M [Department of Orthopaedics of the University of Jena at the Waldkrankenhaus ' Rudolf Elle' , Jena (Germany); Wetzel, W-D [Department of Orthopaedics of the University of Jena at the Waldkrankenhaus ' Rudolf Elle' , Jena (Germany); Hortschansky, P [Hans-Knoell-Institut fuer Naturstoffforschung, Jena (Germany); Schmuck, K [DePuy Biotech GmbH, Jena (Germany); Lohmann, M [Hasylab at DESY, Hamburg (Germany); Reime, B [Hasylab at DESY, Hamburg (Germany); Metge, J [CELLS-ALBA, Universitat Autonoma de Barcelona (Spain); Arfelli, F [Department of Physics, University of Trieste, Trieste (Italy); Menk, R [ELETTRA, Trieste (Italy); Rigon, L [ELETTRA, Trieste (Italy); Muehleman, C [Department of Biochemistry, Rush Medical College, Chicago, IL (United States); Bravin, A [European Synchrotron Radiation Facility, BP220 38043, Grenoble (France); Coan, P [European Synchrotron Radiation Facility, BP220 38043, Grenoble (France); Mollenhauer, J [Department of Orthopaedics of the University of Jena at the Waldkrankenhaus ' Rudolf Elle' , Jena (Germany)

2006-03-07

Diffraction enhanced imaging (DEI) uses refraction of x-rays at edges, which allows pronounced visualization of material borders and rejects scattering which often obscures edges and blurs images. Here, the first evidence is presented that, using DEI, a destruction-free evaluation of the quality of integration of metal implants into bone is possible. Experiments were performed in rabbits and sheep with model implants to investigate the option for DEI as a tool in implant research. The results obtained from DEI were compared to conventional histology obtained from the specimens. DE images allow the identification of the quality of ingrowth of bone into the hydroxyapatite layer of the implant. Incomplete integration of the implant with a remaining gap of less than 0.3 mm caused the presence of a highly refractive edge at the implant/bone border. In contrast, implants with bone fully grown onto the surface did not display a refractive signal. Therefore, the refractive signal could be utilized to diagnose implant healing and/or loosening.

Qualitative evaluation of titanium implant integration into bone by diffraction enhanced imaging

International Nuclear Information System (INIS)

Wagner, A; Sachse, A; Keller, M; Aurich, M; Wetzel, W-D; Hortschansky, P; Schmuck, K; Lohmann, M; Reime, B; Metge, J; Arfelli, F; Menk, R; Rigon, L; Muehleman, C; Bravin, A; Coan, P; Mollenhauer, J

2006-01-01

Diffraction enhanced imaging (DEI) uses refraction of x-rays at edges, which allows pronounced visualization of material borders and rejects scattering which often obscures edges and blurs images. Here, the first evidence is presented that, using DEI, a destruction-free evaluation of the quality of integration of metal implants into bone is possible. Experiments were performed in rabbits and sheep with model implants to investigate the option for DEI as a tool in implant research. The results obtained from DEI were compared to conventional histology obtained from the specimens. DE images allow the identification of the quality of ingrowth of bone into the hydroxyapatite layer of the implant. Incomplete integration of the implant with a remaining gap of less than 0.3 mm caused the presence of a highly refractive edge at the implant/bone border. In contrast, implants with bone fully grown onto the surface did not display a refractive signal. Therefore, the refractive signal could be utilized to diagnose implant healing and/or loosening

Qualitative evaluation of titanium implant integration into bone by diffraction enhanced imaging

Science.gov (United States)

Wagner, A.; Sachse, A.; Keller, M.; Aurich, M.; Wetzel, W.-D.; Hortschansky, P.; Schmuck, K.; Lohmann, M.; Reime, B.; Metge, J.; Arfelli, F.; Menk, R.; Rigon, L.; Muehleman, C.; Bravin, A.; Coan, P.; Mollenhauer, J.

2006-03-01

Diffraction enhanced imaging (DEI) uses refraction of x-rays at edges, which allows pronounced visualization of material borders and rejects scattering which often obscures edges and blurs images. Here, the first evidence is presented that, using DEI, a destruction-free evaluation of the quality of integration of metal implants into bone is possible. Experiments were performed in rabbits and sheep with model implants to investigate the option for DEI as a tool in implant research. The results obtained from DEI were compared to conventional histology obtained from the specimens. DE images allow the identification of the quality of ingrowth of bone into the hydroxyapatite layer of the implant. Incomplete integration of the implant with a remaining gap of less than 0.3 mm caused the presence of a highly refractive edge at the implant/bone border. In contrast, implants with bone fully grown onto the surface did not display a refractive signal. Therefore, the refractive signal could be utilized to diagnose implant healing and/or loosening.

Time-dependent cytokine expression in bone of experimental animals after hydroxyapatite (Hap) implantation

International Nuclear Information System (INIS)

Pilmane, M; Salms, G; Salma, I; Skagers, A; Locs, J; Loca, D; Berzina-Cimdina, L

2011-01-01

Proinflammatory cytokines mediate bone loss around the implants in patients with peri-implant disease. However, there is no complete data about the expression of cytokines into the bone around the implants. The aim of this work was to investigate the distribution and appearance of inflammatory cytokines and anti-inflammatory proteins in the bone of jaw of experimental rabbits in different time periods after HAp implantation. Material was obtained from 8 rabbits in lower jaw 6 and 8 months after HAp implants were placed. Tissues were processed for immunohistochemical detection of tumor necrosis factor alfa (TNFα), Interleukin 1, 6, 8, 10 (IL-1, IL-6, IL-8, IL-10) and defensin 2. Results demonstrated practically unchanged expression of IL-6 and IL-10 between both - experimental and control side 6 months after implantation, while IL-1 and IL-8 notably increased in control side. IL-1 and IL-10 expression did not change in either the experimental side nor the controle side after 8 months HAP implantation, but IL-6 and IL-8 demonstrated a decrease in the control sites. Only IL-8 was elevated with time in experimental sites, while IL-10 showed individual variations in 2 cases.

Time-dependent cytokine expression in bone of experimental animals after hydroxyapatite (Hap) implantation

Energy Technology Data Exchange (ETDEWEB)

Pilmane, M [Riga Stradins University, Institute of Anatomy and Anthropology, Dzirciema 16, LV-1007, Riga (Latvia); Salms, G; Salma, I; Skagers, A [Riga Stradins University, Department of Oral and Maxillofacial Surgery, Dzirciema 20. LV-1007, Riga (Latvia); Locs, J; Loca, D; Berzina-Cimdina, L, E-mail: pilmane@latnet.lv [Riga Technical University, Riga Biomaterials innovation and development centre, Pulka 3/3, LV-1007, Riga (Latvia)

2011-06-23

Proinflammatory cytokines mediate bone loss around the implants in patients with peri-implant disease. However, there is no complete data about the expression of cytokines into the bone around the implants. The aim of this work was to investigate the distribution and appearance of inflammatory cytokines and anti-inflammatory proteins in the bone of jaw of experimental rabbits in different time periods after HAp implantation. Material was obtained from 8 rabbits in lower jaw 6 and 8 months after HAp implants were placed. Tissues were processed for immunohistochemical detection of tumor necrosis factor alfa (TNF{alpha}), Interleukin 1, 6, 8, 10 (IL-1, IL-6, IL-8, IL-10) and defensin 2. Results demonstrated practically unchanged expression of IL-6 and IL-10 between both - experimental and control side 6 months after implantation, while IL-1 and IL-8 notably increased in control side. IL-1 and IL-10 expression did not change in either the experimental side nor the controle side after 8 months HAP implantation, but IL-6 and IL-8 demonstrated a decrease in the control sites. Only IL-8 was elevated with time in experimental sites, while IL-10 showed individual variations in 2 cases.

OCULAR ASPECTS OF HYPERTHYROIDISM WITH SPECIAL REFERENCE TO OCULAR MYOPATHY

Directory of Open Access Journals (Sweden)

Mallika O. U

2017-04-01

Full Text Available BACKGROUND Hyperthyroidism can result in ocular manifestations even before systemic signs and symptoms develop. It is seen more in females and severe forms are more common in males. Early detection of ocular involvement can prevent vision threatening complications and troublesome discomforts affecting quality of vision. This clinical study highlights the importance of detailed ocular examination in hyperthyroidism. MATERIALS AND METHODS Fifty consecutive patients with ocular signs of hyperthyroidism were evaluated and followed up for an average period of 1 year. Detailed ocular examination included exophthalmometric measurements, ocular movements and Worth four-dot test. T3, T4, TSH, CT scan and antimicrosomal antibodies and antithyroglobulin antibodies were done along with routine investigations. Study Design- Prospective cohort study. RESULTS Statistical analysis did not reveal any correlation between the level of serum T3 and severity of ocular findings. Majority of the cases were euthyroid with moderate ocular myopathy having multiple muscle involvement. Inferior rectus was affected most. CONCLUSION The ocular signs of hyperthyroidism in the present study seem to be mild. The severe eye changes like corneal involvement and optic nerve changes were less common.

In situ annealing of hydroxyapatite thin films

International Nuclear Information System (INIS)

Johnson, Shevon; Haluska, Michael; Narayan, Roger J.; Snyder, Robert L.

2006-01-01

Hydroxyapatite is a bioactive ceramic that mimics the mineral composition of natural bone. Unfortunately, problems with adhesion, poor mechanical integrity, and incomplete bone ingrowth limit the use of many conventional hydroxyapatite surfaces. In this work, we have developed a novel technique to produce crystalline hydroxyapatite thin films involving pulsed laser deposition and postdeposition annealing. Hydroxyapatite films were deposited on Ti-6Al-4V alloy and Si (100) using pulsed laser deposition, and annealed within a high temperature X-ray diffraction system. The transformation from amorphous to crystalline hydroxyapatite was observed at 340 deg. C. Mechanical and adhesive properties were examined using nanoindentation and scratch adhesion testing, respectively. Nanohardness and Young's modulus values of 3.48 and 91.24 GPa were realized in unannealed hydroxyapatite films. Unannealed and 350 deg. C annealed hydroxyapatite films exhibited excellent adhesion to Ti-6Al-4V alloy substrates. We anticipate that the adhesion and biological properties of crystalline hydroxyapatite thin films may be enhanced by further consideration of deposition and annealing parameters

Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

Science.gov (United States)

Shrivastava, Pragya; Dalai, Sridhar; Sudera, Prerna; Sivam, Santosh Param; Vijayalakshmi, S.; Sharma, Pratibha

2013-02-01

With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO2 70 mol%, CaO 26 mol % and P2O5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

International Nuclear Information System (INIS)

Shrivastava, Pragya; Dalai, Sridhar; Vijayalakshmi, S.; Sudera, Prerna; Sivam, Santosh Param; Sharma, Pratibha

2013-01-01

With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO 2 70 mol%, CaO 26 mol % and P 2 O 5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

Characterization of Intraocular Pressure Increases and Management Strategies Following Treatment With Fluocinolone Acetonide Intravitreal Implants in the FAME Trials.

Science.gov (United States)

Parrish, Richard K; Campochiaro, Peter A; Pearson, P Andrew; Green, Ken; Traverso, Carlo E

2016-05-01

To compare elevated intraocular pressure (IOP) management and outcomes among patients with diabetic macular edema who received fluocinolone acetonide (FAc) implants versus sham-control treatment and explore the prior ocular steroid exposure impact on IOP outcomes. Best-corrected visual acuity (BCVA) was measured using Early Treatment Diabetic Retinopathy Study charts or electronic VA testers. Goldmann applanation tonometry was used to measure IOP. Elevated IOP was more common in FAc-versus sham control-treated patients. Medication, and less often trabeculoplasty or surgery, was used to lower IOP without affecting VA outcomes. No patient treated with 0.2 µg/day FAc who received prior ocular steroid required IOP-lowering surgery. Elevated IOP may occur following FAc implant receipt; however, in the present study, it was manageable and did not impact vision outcomes. Patients previously treated with ocular steroid did not require IOP-lowering surgery following 0.2 µg/day FAc implant administration. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:426-435.]. Copyright 2016, SLACK Incorporated.

Alveolar Ridge Augmentation with Three-Dimensional Printed Hydroxyapatite Devices: A Preclinical Study.

Science.gov (United States)

Fiorellini, Joseph P; Norton, Michael R; Luan, Kevin WanXin; Kim, David Minjoon; Wada, Kei; Sarmiento, Hector L

2018-02-14

The objective of this study was to evaluate the effectiveness of precise three-dimensional hydroxyapatite printed micro- and macrochannel devices for alveolar ridge augmentation in a canine model. All grafts induced minimal inflammatory and fibrotic reactions. Examination of undecalcified sections revealed that both types of grafts demonstrated bone ingrowth. The majority of the bone growth into the block graft was into the channels, though a portion grew directly into the construct in the form of small bony spicules. In conclusion, bone ingrowth was readily demonstrated in the middle of the implanted printed devices.

The Kinetics of Ampicillin Release from Hydroxyapatite for Bones Regeneration

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Giovanilton Ferreira da Silva

2009-01-01

Full Text Available Semisynthetic beta-lactam antibiotics are among the most used pharmaceuticals. Their use in veterinary and human medicine is in continuous expansion. There is a growing need for developing bioactive implants. Advantages of implantable drug delivery tools can include high release efficiency, precise dose control, low toxicity, and allow to overcome disadvantages connected with conventional methods. In this respect, hydroxyapatite (HA is an elective material. It enables to produce architectures similar to those of real bones. Here we studied a kinetic model to describe ampicillin release from HA. In the course of adsorption experiment, ampicillin was dissolved, maintained at 30∘C and shaken at 60 strokes/minute. Samples were withdrawn periodically for analysis and then returned to the mixture. Adsorbed amounts were measured by the difference of the concentration of the antibiotics before and after adsorption using UV adsorption at 225 nm. The aim of this work was to evaluate its application as ampicillin delivery carrier.

Study on nano-structured hydroxyapatite/zirconia stabilized yttria on healing of articular cartilage defect in rabbit

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Amir Sotoudeh

2013-05-01

Full Text Available PURPOSE: Articular Cartilage has limited potential for self-repair and tissue engineering approaches attempt to repair articular cartilage by scaffolds. We hypothesized that the combined hydroxyapatite and zirconia stabilized yttria would enhance the quality of cartilage healing. METHODS: In ten New Zealand white rabbits bilateral full-thickness osteochondral defect, 4 mm in diameter and 3 mm depth, was created on the articular cartilage of the patellar groove of the distal femur. In group I the scaffold was implanted into the right stifle and the same defect was created in the left stifle without any transplant (group II. Specimens were harvested at 12 weeks after implantation, examined histologically for morphologic features, and stained immunohistochemically for type-II collagen. RESULTS: In group I the defect was filled with a white translucent cartilage tissue In contrast, the defects in the group II remained almost empty. In the group I, the defects were mostly filled with hyaline-like cartilage evidenced but defects in group II were filled with fibrous tissue with surface irregularities. Positive immunohistochemical staining of type-II collagen was observed in group I and it was absent in the control group. CONCLUSION: The hydroxyapatite/yttria stabilized zirconia scaffold would be an effective scaffold for cartilage tissue engineering.

Ocular Melanoma

Science.gov (United States)

... is Ocular Melanoma? Leer en Español: ¿Qué es el melanoma ocular? Written By: Daniel Porter Reviewed By: Robert H Janigian Jr MD Sep. 01, 2017 Ocular melanoma (melanoma in or around the eye) is a type of cancer that develops in the cells that produce pigment. ...

Comparative physical, chemical and biological assessment of simple and titanium-doped ovine dentine-derived hydroxyapatite coatings fabricated by pulsed laser deposition

Science.gov (United States)

Duta, L.; Mihailescu, N.; Popescu, A. C.; Luculescu, C. R.; Mihailescu, I. N.; Çetin, G.; Gunduz, O.; Oktar, F. N.; Popa, A. C.; Kuncser, A.; Besleaga, C.; Stan, G. E.

2017-08-01

We report on the synthesis by Pulsed Laser Deposition of simple and Ti doped hydroxyapatite thin films of biological (ovine dentine) origin. Detailed physical, chemical, mechanical and biological investigations were performed. Morphological examination of films showed a surface composed of spheroidal particulates, of micronic size. Compositional analyses pointed to the presence of typical natural doping elements of bone, along with a slight non-stoichiometry of the deposited films. Structural investigations proved the monophasic hydroxyapatite nature of both simple and Ti doped films. Ti doping of biological hydroxyapatite induced an overall downgrade of the films crystallinity together with an increase of the films roughness. It is to be emphasized that bonding strength values measured at film/Ti substrate interface were superior to the minimum value imposed by International Standards regulating the load-bearing implant coatings. In vitro tests on Ti doped structures, compared to simple ones, revealed excellent biocompatibility in human mesenchymal stem cell cultures, a higher proliferation rate and a good cytocompatibility. The obtained results aim to elucidate the overall positive role of Ti doping on the hydroxyapatite films performance, and demonstrate the possibility to use this novel type of coatings as feasible materials for future implantology applications.

Hydroxyapatite synthesis using EDTA

Science.gov (United States)

Kang, Nak Heon; Kim, Soon Je; Song, Seung Han; Choi, Sang mun; Choi, Sik Young; Kim, Youn Jung

2013-01-01

Bone comprises structure of body and is consisted of inorganic substances. It exists in an organic structure in the body. Even though it is firm and has self healing mechanism, it can be damaged by trauma, cancer, or bone diseases. Allograft can be an alternative solution for autologous bone graft. Hydroxyapatite(Ca10(PO4)6(OH)2), an excellent candidate for allograft, can be applied to bone defect area. There are several methods to produce hydroxyapatite, however economical cost and time consuming make the production difficult. In this study we synthesized the hydroxyapatite with Ethyenediamine tetraacetic acid. Freeze Dried Bone Allograft(Hans Biomed) was used to be a control group. Synthesized hydroxyapatite was a rod shape, white powdery type substance with 2 ~ 5 μm length and 0.5 ~ 1 μm width. X-ray diffraction showed the highest sharp peak at 32° and high peaks at 25.8°, 39.8°, 46.8°, 49.5°, and 64.0° indicating a similar substance to the freeze Dried Bone Allograft. 3 days after the cell growth of synthesized hydroxyapatite showed 1.5 fold more than the Bone Allograft. Cellular and media alkaline phosphate activity increased similar to the bone alloagraft. In this study we came up with a new method to produce the hydroxyapatite. It is a convenient method that can be held in room temperature and low pressure. Also the the product can be manufactured in large quantity. It can be also transformed into scaffold structure which will perform a stronger configuration. The manufacturing method will help the bony defect patients and make future medical products. PMID:23714942

Hydroxyapatite synthesis using EDTA.

Science.gov (United States)

Kang, Nak Heon; Kim, Soon Je; Song, Seung Han; Choi, Sang mun; Choi, Sik Young; Kim, Youn Jung

2013-05-01

Bone comprises structure of the body and consisted of inorganic substances. It exists in an organic structure in the body. Even though it is firm and has self-healing mechanism, it can be damaged by trauma, cancer, or bone diseases. Allograft can be an alternative solution for autologous bone graft. Hydroxyapatite (Ca10(PO4)6(OH)2), an excellent candidate for allograft, can be applied to bone defect area. There are several methods to produce hydroxyapatite; however, economical cost and being time consuming make the production difficult. In this study, we synthesized hydroxyapatite with EDTA. Freeze-dried bone allograft (Hans Biomed) was used as the control group. Synthesized hydroxyapatite was a rod-shaped, white powdery substance with 2- to 5-μm length and 0.5- to 1-μm width. X-ray diffraction showed the highest sharp peak at 32°C and high peaks at 25.8°C, 39.8°C, 46.8°C, 49.5°C, and 64.0°C, indicating a similar substance to the freeze-dried bone allograft. After 3 days, the cell growth of synthesized hydroxyapatite showed 1.5-fold more than did the bone allograft. Cellular and media alkaline phosphate activity increased similar to the bone allograft. In this study, we came up with a new method to produce the hydroxyapatite. It is a convenient method that can be held in room temperature and low pressure. Also, the product can be manufactured in large quantity. It can be also transformed into scaffold structure, which will perform a stronger configuration. The manufacturing method will help the bony defect patients and make future medical products.

Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: Promising bone implant materials

Science.gov (United States)

Oyefusi, Adebola; Olanipekun, Opeyemi; Neelgund, Gururaj M.; Peterson, Deforest; Stone, Julia M.; Williams, Ebonee; Carson, Laura; Regisford, Gloria; Oki, Aderemi

2014-11-01

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method. Optimisation, characterisation and rheology.

Science.gov (United States)

Tredwin, Christopher J; Young, Anne M; Georgiou, George; Shin, Song-Hee; Kim, Hae-Won; Knowles, Jonathan C

2013-02-01

Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application. It was the objective of this study to characterise and optimise the production of Hydroxyapatite (HA), fluorhydroxyapatite (FHA) and fluorapatite (FA) using a sol-gel technique and assess the rheological properties of these materials. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethylphosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the sol-gel derived FHA and FA. Optimisation of the chemistry and subsequent characterisation of the sol-gel derived materials was carried out using X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). Rheology of the sol-gels was investigated using a viscometer and contact angle measurement. A protocol was established that allowed synthesis of HA, FHA and FA that were at least 99% phase pure. The more fluoride incorporated into the apatite structure; the lower the crystallisation temperature, the smaller the unit cell size (changes in the a-axis), the higher the viscosity and contact angle of the sol-gel derived apatite. A technique has been developed for the production of HA, FHA and FA by the sol-gel technique. Increasing fluoride substitution in the apatite structure alters the potential coating properties. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite as a potential bone graft substitute material

Science.gov (United States)

Florschutz, Anthony Vatroslav

implanted ectopically in a rodent animal model and histologically evaluated for biocompatibility, degradation, and bone formation in vivo. The gelatin-hydroxyapatite scaffolds retained dimensional structure over 28 days and did not elicit any undesirable systemic or local effects. Distinct areas of mineralization and osteoid/bone were noted in all the implanted scaffolds and quantitative differences were primarily dependent on the presence of hydroxyapatite.

Resident-performed Ex-PRESS shunt implantation versus trabeculectomy.

Science.gov (United States)

Seider, Michael I; Rofagha, Soraya; Lin, Shan C; Stamper, Robert L

2012-09-01

To compare outcomes between resident-performed trabeculectomy and Ex-PRESS shunt implantation. A consecutive cohort of 36 Ex-PRESS shunt implantations and 57 trabeculectomies (1 eye/patient) performed by resident surgeons in their third year of ophthalmic training at the University of California, San Francisco and at the San Francisco Veterans Administration Hospital, under the supervision of a single glaucoma fellowship-trained surgeon were included in this study. Eyes with PRESS shunt groups at all follow-up points. On average, the Ex-PRESS shunt group required significantly less ocular antihypertensive medication to control IOP at 3 months postoperative (P=0.01), but no difference was found at 6 months or 1 year (all, P≥0.28). A larger proportion of Ex-PRESS shunt patients had good IOP control without medication at 3 (P=0.057) and 6 months (P=0.076) postoperatively. No difference was found in the rates of sight-threatening complications between groups (all, P≥0.22). In the hands of ophthalmology residents in their third year of training, the trabeculectomy and Ex-PRESS shunt implantation procedures perform comparably in terms of postoperative IOP control, reduction in patient dependence on ocular antihypertensive medications, and risk of complication in our population.

Silica enhanced formation of hydroxyapatite nanocrystals in simulated body fluid (SBF) at 37 deg. C

Energy Technology Data Exchange (ETDEWEB)

Sadjadi, M.S., E-mail: m.s.sadjad@gmail.com [Department of Chemistry, Sciences and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Ebrahimi, H.R. [Department of Chemistry, Sciences and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Meskinfam, M. [Department of Chemistry, Tonekabon Branch, Islamic Azad University, Tonekabon (Iran, Islamic Republic of); Zare, K. [Department of Chemistry, University of Shahid Beheshti, Eveen Tehran (Iran, Islamic Republic of)

2011-10-17

Highlights: {yields} We report on fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in silica-containing simulated body fluid solution at 37 deg. C. {yields} Bioactivity and biodegradability of TCP precursor have been confirmed by the dissolution of TCP and formation of a bone like layer of new HA nanoparticles outside of the precursor after 24 h soaking in SBF solution. {yields} Successive nucleation and formation of tiny hexagonal HA nanoplates and nanorods have been confirmed by TEM results after 24 h soaking of TCP in silica-containing BSF solution. - Abstract: The chemical modification of implant (prosthesis) surfaces is being investigated worldwide for improving the fixation of orthopaedic and dental implants. The main goal in this surface modification approach is to achieve a faster bone growth and chemical bonding of the implant to the newly generated and/or remodeled bone. In this work, we report fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in simulated body fluid (SBF, inorganic components of human blood plasma) solutions at 37 deg. C, using calcium phosphate (TCP) and sodium silicate as precursors. Characterization and chemical analysis of the synthesized powders were performed by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated enhanced nucleation and formation of bone like layer of HA nanocrystals at the surface of TCP nanoparticles and occurrence of HA nanocrystals during 24 h soaking of TCP in SBF solution containing silica ions. The average size of a nanoparticle, using Scherrer formula, was found to be 18.2 nm.

Silica enhanced formation of hydroxyapatite nanocrystals in simulated body fluid (SBF) at 37 deg. C

International Nuclear Information System (INIS)

Sadjadi, M.S.; Ebrahimi, H.R.; Meskinfam, M.; Zare, K.

2011-01-01

Highlights: → We report on fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in silica-containing simulated body fluid solution at 37 deg. C. → Bioactivity and biodegradability of TCP precursor have been confirmed by the dissolution of TCP and formation of a bone like layer of new HA nanoparticles outside of the precursor after 24 h soaking in SBF solution. → Successive nucleation and formation of tiny hexagonal HA nanoplates and nanorods have been confirmed by TEM results after 24 h soaking of TCP in silica-containing BSF solution. - Abstract: The chemical modification of implant (prosthesis) surfaces is being investigated worldwide for improving the fixation of orthopaedic and dental implants. The main goal in this surface modification approach is to achieve a faster bone growth and chemical bonding of the implant to the newly generated and/or remodeled bone. In this work, we report fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in simulated body fluid (SBF, inorganic components of human blood plasma) solutions at 37 deg. C, using calcium phosphate (TCP) and sodium silicate as precursors. Characterization and chemical analysis of the synthesized powders were performed by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated enhanced nucleation and formation of bone like layer of HA nanocrystals at the surface of TCP nanoparticles and occurrence of HA nanocrystals during 24 h soaking of TCP in SBF solution containing silica ions. The average size of a nanoparticle, using Scherrer formula, was found to be 18.2 nm.

Bone tissue engineering with a collagen–hydroxyapatite scaffold and culture expanded bone marrow stromal cells

Science.gov (United States)

Villa, Max M.; Wang, Liping; Huang, Jianping; Rowe, David W.; Wei, Mei

2015-01-01

Osteoprogenitor cells combined with supportive biomaterials represent a promising approach to advance the standard of care for bone grafting procedures. However, this approach faces challenges, including inconsistent bone formation, cell survival in the implant, and appropriate biomaterial degradation. We have developed a collagen–hydroxyapatite (HA) scaffold that supports consistent osteogenesis by donor derived osteoprogenitors, and is more easily degraded than a pure ceramic scaffold. Herein, the material properties are characterized as well as cell attachment, viability, and progenitor distribution in vitro. Furthermore, we examined the biological performance in vivo in a critical-size mouse calvarial defect. To aid in the evaluation of the in-house collagen–HA scaffold, the in vivo performance was compared with a commercial collagen–HA scaffold (Healos®, Depuy). The in-house collagen–HA scaffold supported consistent bone formation by predominantly donor-derived osteoblasts, nearly completely filling a 3.5 mm calvarial defect with bone in all samples (n=5) after 3 weeks of implantation. In terms of bone formation and donor cell retention at 3 weeks postimplantation, no statistical difference was found between the in-house and commercial scaffold following quantitative histomorphometry. The collagen–HA scaffold presented here is an open and well-defined platform that supports robust bone formation and should facilitate the further development of collagen–hydroxyapatite biomaterials for bone tissue engineering. PMID:24909953

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.

Lanthanum-silicon-substituted hydroxyapatite: Mechanochemical synthesis and prospects for medical applications

Energy Technology Data Exchange (ETDEWEB)

Chaikina, M. V., E-mail: chaikinam@solid.nsc.ru; Bulina, N. V., E-mail: bulina@solid.nsc.ru; Prosanov, I. Yu., E-mail: prosanov@mail.ru [Institute of Solid State Chemistry and Mechanochemistry SB RAS, Kutateladze Street 18, Novosibirsk, 630128 (Russian Federation); Komarova, E. G., E-mail: katerina@ispms.tsc.ru; Sharkeev, Yu. P., E-mail: sharkeev@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Academicheskii Pr. 2/4, Tomsk, 634055 (Russian Federation)

2016-08-02

The paper presents the results of mechanochemical synthesis of hydroxyapatite (HAP) with simultaneous substitutions of lanthanum (La{sup 3+}) for calcium ions and silicate ((SiO{sub 4}){sup 4−}-group) for the phosphate group with the substituent concentrations in the range 0.2–2.0 mol per HAP mol. The use of Si-substituted HAP as a coating material promotes accelerated osteosynthesis and osteointegration of implants into the bone tissue. The replacement of calcium ions by La{sup 3+} in the HAP structure plays an antimicrobial role preventing inflammatory processes. Annealing-induced variations in the lattice parameters of synthesized samples indicate the substituent incorporation into the HAP structure. It is known that complex compounds with lanthanides are used for cancer chemotherapy. In particular, La plays a key role in the course of treatment of injured defects of bone tissue. In addition, La-substituted HAP can be used for filling bone defects and coating implants in postoperational areas affected by bone cancer.

Long-term ocular complications in aphakic versus pseudophakic eyes of children with juvenile idiopathic arthritis-associated uveitis

NARCIS (Netherlands)

Sijssens, K. M.; Los, L. I.; Rothova, A.; Schellekens, P. A. W. J. F.; van de Does, P.; Stilma, J. S.; de Boer, H. J.

Aim To evaluate the long-term follow-up of aphakic and pseudophakic eyes of children with juvenile idiopathic arthritis (JIA)-associated uveitis with a special interest in whether intraocular lens implantation increases the risk of developing ocular complications. Methods Data were obtained from the

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...

Synthesis and chemical and structural characterization of hydroxyapatite obtained from eggshell and tricalcium phosphate

OpenAIRE

Arboleda, Alejandro; Franco, Manuel; Caicedo, Julio; Tirado, Liliana; Goyes, Clara

2016-01-01

The eggshell is a common residue that is usually discarded without giving any use to it. In this paper the results obtained from a proposed procedure to get hydroxyapatite (HA) from eggshell are shown. The HA is a calcium phosphate which has been widely used as implant material due to the close similarity of its composition with the inorganic phase of natural bone. HA generally has a high cost and it is presented as micro and nanostructured bioceramics; the last one is a promising option for ...

Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

International Nuclear Information System (INIS)

Chao, Shao Ching; Wang, Ming-Jia; Pai, Nai-Su; Yen, Shiow-Kang

2015-01-01

Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO 3 ) 2 , NH 4 H 2 PO 4 and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space

Surface characterization of titanium based dental implants; Caracterizacao de implantes odontologicos a base de titanio

Energy Technology Data Exchange (ETDEWEB)

Castilho, Guilherme Augusto Alcaraz

2006-07-01

Dental implantology uses metallic devices made of commercially pure titanium in order to replace lost teeth. Titanium presents favorable characteristics as bio material and modern implants are capable of integrate, witch is the union between bone and implant without fibrous tissue development. Three of the major Brazilian implant manufacturers were chosen to join the study. A foreign manufacturer participated as standard. The manufacturers had three specimens of each implant with two different surface finishing, as machined and porous, submitted to analysis. Surface chemical composition and implant morphology were analyzed by X-ray photoelectron spectroscopy (XP S), scanning electron microscopy (SEM) and microprobe. Implant surface is mainly composed of titanium, oxygen and carbon. Few contaminants commonly present on implant surface were found on samples. Superficial oxide layer is basically composed of titanium dioxide (TiO{sub 2}), another oxides as Ti O and Ti{sub 2}O{sub 3} were also found in small amount. Carbon on implant surface was attributed to manufacturing process. Nitrogen, Phosphorous and Silicon appeared in smaller concentration on surface. There was no surface discrepancy among foreign and Brazilian made implants. SEM images were made on different magnification, 35 X to 3500 X, and showed similarity among as machined implants. Porous surface finishing implants presented distinct morphology. This result was attributed to differences on manufacturing process. Implant bioactivity was accessed through immersion on simulated body solution (SBF) in order to verify formation of an hydroxyapatite (HA) layer on surface. Samples were divided on three groups according to immersion time: G1 (7 days), G2 (14 days), G3 (21 days), and deep in SBF solution at 37 deg C. After being removed from solution, XPS analyses were made and then implants have been submitted to microprobe analysis. XPS showed some components of SBF solution on sample surface but microprobe

Comparative physical, chemical and biological assessment of simple and titanium-doped ovine dentine-derived hydroxyapatite coatings fabricated by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Duta, L.; Mihailescu, N.; Popescu, A.C.; Luculescu, C.R. [National Institute for Lasers, Plasma and Radiation Physics, 077125 Magurele (Romania); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, 077125 Magurele (Romania); Çetin, G.; Gunduz, O. [Department of Bioengineering, Faculty of Engineering, Marmara University, 34722 Istanbul (Turkey); Oktar, F.N. [Department of Bioengineering, Faculty of Engineering, Marmara University, 34722 Istanbul (Turkey); Department of Medical Imaging Techniques, Vocational School of Health Services, Marmara University, 34668 Istanbul (Turkey); Nanotechnology and Biomaterials Application & Research Centre, Marmara University, 34722 Istanbul (Turkey); Popa, A.C. [National Institute of Materials Physics, 077125 Magurele (Romania); Army Centre for Medical Research, 010195 Bucharest (Romania); Kuncser, A.; Besleaga, C. [National Institute of Materials Physics, 077125 Magurele (Romania); Stan, G.E., E-mail: george_stan@infim.ro [National Institute of Materials Physics, 077125 Magurele (Romania)

2017-08-15

Highlights: • Pulsed laser deposition of Ti doped hydroxyapatite films of biological origin. • Downgrade of films’ crystallinity and increase of roughness induced by Ti doping. • Bonding strength values superior to minimum value imposed by ISO standards. • Excellent biocompatibility in hMSC cultures of Ti doped structures. • Ti doped hydroxyapatite films as feasible materials for implantology applications. - Abstract: We report on the synthesis by Pulsed Laser Deposition of simple and Ti doped hydroxyapatite thin films of biological (ovine dentine) origin. Detailed physical, chemical, mechanical and biological investigations were performed. Morphological examination of films showed a surface composed of spheroidal particulates, of micronic size. Compositional analyses pointed to the presence of typical natural doping elements of bone, along with a slight non-stoichiometry of the deposited films. Structural investigations proved the monophasic hydroxyapatite nature of both simple and Ti doped films. Ti doping of biological hydroxyapatite induced an overall downgrade of the films crystallinity together with an increase of the films roughness. It is to be emphasized that bonding strength values measured at film/Ti substrate interface were superior to the minimum value imposed by International Standards regulating the load-bearing implant coatings. In vitro tests on Ti doped structures, compared to simple ones, revealed excellent biocompatibility in human mesenchymal stem cell cultures, a higher proliferation rate and a good cytocompatibility. The obtained results aim to elucidate the overall positive role of Ti doping on the hydroxyapatite films performance, and demonstrate the possibility to use this novel type of coatings as feasible materials for future implantology applications.

Comparative physical, chemical and biological assessment of simple and titanium-doped ovine dentine-derived hydroxyapatite coatings fabricated by pulsed laser deposition

International Nuclear Information System (INIS)

Duta, L.; Mihailescu, N.; Popescu, A.C.; Luculescu, C.R.; Mihailescu, I.N.; Çetin, G.; Gunduz, O.; Oktar, F.N.; Popa, A.C.; Kuncser, A.; Besleaga, C.; Stan, G.E.

2017-01-01

Highlights: • Pulsed laser deposition of Ti doped hydroxyapatite films of biological origin. • Downgrade of films’ crystallinity and increase of roughness induced by Ti doping. • Bonding strength values superior to minimum value imposed by ISO standards. • Excellent biocompatibility in hMSC cultures of Ti doped structures. • Ti doped hydroxyapatite films as feasible materials for implantology applications. - Abstract: We report on the synthesis by Pulsed Laser Deposition of simple and Ti doped hydroxyapatite thin films of biological (ovine dentine) origin. Detailed physical, chemical, mechanical and biological investigations were performed. Morphological examination of films showed a surface composed of spheroidal particulates, of micronic size. Compositional analyses pointed to the presence of typical natural doping elements of bone, along with a slight non-stoichiometry of the deposited films. Structural investigations proved the monophasic hydroxyapatite nature of both simple and Ti doped films. Ti doping of biological hydroxyapatite induced an overall downgrade of the films crystallinity together with an increase of the films roughness. It is to be emphasized that bonding strength values measured at film/Ti substrate interface were superior to the minimum value imposed by International Standards regulating the load-bearing implant coatings. In vitro tests on Ti doped structures, compared to simple ones, revealed excellent biocompatibility in human mesenchymal stem cell cultures, a higher proliferation rate and a good cytocompatibility. The obtained results aim to elucidate the overall positive role of Ti doping on the hydroxyapatite films performance, and demonstrate the possibility to use this novel type of coatings as feasible materials for future implantology applications.

Recent progress on fabrication and drug delivery applications of nanostructured hydroxyapatite.

Science.gov (United States)

Mondal, Sudip; Dorozhkin, Sergy V; Pal, Umapada

2018-07-01

Through this brief review, we provide a comprehensive historical background of the development of nanostructured hydroxyapatite (nHAp), and its application potentials for controlled drug delivery, drug conjugation, and other biomedical treatments. Aspects associated with efficient utilization of hydroxyapatite (HAp) nanostructures such as their synthesis, interaction with drug molecules, and other concerns, which need to be resolved before they could be used as a potential drug carrier in body system, are discussed. This review focuses on the evolution of perceptions, practices, and accomplishments in providing improved delivery systems for drugs until date. The pioneering developments that have presaged today's fascinating state of the art drug delivery systems based on HAp and HAp-based composite nanostructures are also discussed. Special emphasis has been given to describe the application and effectiveness of modified HAp as drug carrier agent for different diseases such as bone-related disorders, carriers for antibiotics, anti-inflammatory, carcinogenic drugs, medical imaging, and protein delivery agents. As only a very few published works made comprehensive evaluation of HAp nanostructures for drug delivery applications, we try to cover the three major areas: concepts, practices and achievements, and applications, which have been consolidated and patented for their practical usage. The review covers a broad spectrum of nHAp and HAp modified inorganic drug carriers, emphasizing some of their specific aspects those needed to be considered for future drug delivery applications. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease Nanotechnology Approaches to Biology > Cells at the Nanoscale. © 2017 Wiley Periodicals, Inc.

Miopatia ocular descendente Descending ocular myopathy: a case report

Directory of Open Access Journals (Sweden)

Marcos R. G. de Freitas

1975-06-01

Full Text Available Os autores apresentam caso de paciente jovem, do sexo feminino, com afecção muscular primária ocular e faríngea sem caráter familial. Foram feitos estudos eletromiográficos e histopatológicos musculares que confirmam o caráter miogênico do processo. É feita comparação entre a miopatia ocular e a miopatia ocular descendente, acreditando os autores que seriam variantesThe case of a 23 years old female patient, with primary involvement of the extraocular and faringeal muscles without familiar history is reported. Electromyographic and muscular biopsy studies proved the myogenic nature of the process. A clinical comparison between the ocular myopathy and the descending ocular myopathy is made, the authors thinking that both of them would be variants of the same muscle disease.

Antibacterial Efficiency of Hydroxyapatite Biomaterials with Biodegradable Polylactic Acid and Polycaprolactone Polymers Saturated with Antibiotics / Bionoārdāmu Polimēru Saturošu Un Ar Antibiotiskajām Vielām Piesūcinātu Biomateriālu Antibakteriālās Efektivitātes Noteikšana

Directory of Open Access Journals (Sweden)

Kroiča Juta

2016-08-01

Full Text Available Infections continue to spread in all fields of medicine, and especially in the field of implant biomaterial surgery, and not only during the surgery, but also after surgery. Reducing the adhesion of bacteria could decrease the possibility of biomaterial-associated infections. Bacterial adhesion could be reduced by local antibiotic release from the biomaterial. In this in vitro study, hydroxyapatite biomaterials with antibiotics and biodegradable polymers were tested for their ability to reduce bacteria adhesion and biofilm development. This study examined the antibacterial efficiency of hydroxyapatite biomaterials with antibiotics and biodegradable polymers against Staphylococcus epidermidis and Pseudomonas aeruginosa. The study found that hydroxyapatite biomaterials with antibiotics and biodegradable polymers show longer antibacterial properties than hydroxyapatite biomaterials with antibiotics against both bacterial cultures. Therefore, the results of this study demonstrated that biomaterials that are coated with biodegradable polymers release antibiotics from biomaterial samples for a longer period of time and may be useful for reducing bacterial adhesion on orthopedic implants.

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

Parente, P., E-mail: pparente@icv.csic.es [Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, Madrid 28049 (Spain); Savoini, B. [Departamento de Fisica, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganes 28911 (Spain); Ferrari, B. [Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, Madrid 28049 (Spain); Monge, M.A.; Pareja, R. [Departamento de Fisica, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganes 28911 (Spain); Sanchez-Herencia, A.J. [Instituto de Ceramica y Vidrio, CSIC, C/Kelsen 5, Madrid 28049 (Spain)

2013-03-01

The capability of the colloidal method to produce yttria (Y{sub 2}O{sub 3}) dispersed hydroxyapatite (HA) has been investigated as an alternative method to the conventional method of mechanical mixing and sintering for developing HA-based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce HA materials with highly dispersed Y{sub 2}O{sub 3} has been applied, and the effect of 10 wt.% Y{sub 2}O{sub 3} addition to HA investigated by thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy. These measurements evidence a remarkable effect of this Y{sub 2}O{sub 3} addition on decomposition mechanisms of synthetic HA. Results show that incorporation of Y{sub 2}O{sub 3} as dispersed second phase is beneficial because it hinders the decomposition mechanisms of HA into calcium phosphates. This retardation will allow the control of the sintering conditions for developing HA implants with improved properties. Besides, substitution of Ca{sup 2+} with Y{sup 3+} ions appears to promote the formation of OH{sup -} vacancies, which could improve the conductive properties of HA favorable to osseointegration. - Highlights: Black-Right-Pointing-Pointer We reveal the influence of Y{sub 2}O{sub 3} on thermal stability of hydroxyapatite. Black-Right-Pointing-Pointer Incorporation of Y{sub 2}O{sub 3} delays decomposition of hydroxyapatite to calcium phosphates. Black-Right-Pointing-Pointer Addition of Y{sub 2}O{sub 3} enables sintering conditions more favorable to the densification.

Hydroxyapatite grafted carbon nanotubes and graphene nanosheets: promising bone implant materials.

Science.gov (United States)

Oyefusi, Adebola; Olanipekun, Opeyemi; Neelgund, Gururaj M; Peterson, Deforest; Stone, Julia M; Williams, Ebonee; Carson, Laura; Regisford, Gloria; Oki, Aderemi

2014-11-11

In the present study, hydroxyapatite (HA) was successfully grafted to carboxylated carbon nanotubes (CNTs) and graphene nanosheets. The HA grafted CNTs and HA-graphene nanosheets were characterized using FT-IR, TGA, SEM and X-ray diffraction. The HA grafted CNTs and graphene nanosheets (CNTs-HA and Gr-HA) were further used to examine the proliferation and differentiation rate of temperature-sensitive human fetal osteoblastic cell line (hFOB 1.19). Total protein assays and western blot analysis of osteocalcin expression were used as indicators of cell proliferation and differentiation. Results indicated that hFOB 1.19 cells proliferate and differentiate well in treatment media containing CNTs-HA and graphene-HA. Both CNTs-HA and graphene-HA could be promising nanomaterials for use as scaffolds in bone tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

A comparison of resistance to fracture among four commercially available forms of hydroxyapatite cement.

Science.gov (United States)

Miller, Lee; Guerra, Aldo Benjamin; Bidros, Rafi Sirop; Trahan, Christopher; Baratta, Richard; Metzinger, Stephen Eric

2005-07-01

Hydroxyapatite cement is a relatively new biomaterial that has found widespread use in craniomaxillofacial surgery. Despite its common usage, complication rates as high as 32% have been reported. When failed implants are removed, implant fracture has been cited as a potential cause of failure. The purpose of this study was to evaluate resistance to fracture among 4 commercially available hydroxyapatite cement formulations. The materials tested included Norian Craniofacial Repair System (carbonated apatite cement) (AO North America, Devon, PA), Norian CRS Fast Set Putty (carbonated apatite cement) (AO North America), BoneSource (hydroxyapatite cement) (Stryker Leibinger, Portage, MI), and Mimix (hydroxyapatite cement) (Walter Lorenz Surgical, Inc, Jacksonville, FL). To ensure consistency, all materials were embedded in acrylic wells. Each material was placed into a well 2.54 cm in diameter and 0.953 cm in thickness. The materials were prepared per manufacturer specifications. All materials were incubated at 37.0 degrees C, in 6% CO2, 100% humidity for 36 hours. Using the Bionix MTS Test System, a 12-mm-diameter probe applied incremental force to the center of the disk at a rate of 0.1 mm per second. The transmitted force was measured using a Bionix MTS Axial-Torsional Load Transducer for each disk. The force which resulted in fracture was recorded for each material. Ten disks of each material were processed by this method, for a total of 40 disks. The significance of resistance to fracture for the 4 compounds was analyzed using 1-way analysis of variance with post hoc Scheffe method. Mean fracture force with related P values was plotted for direct comparison of group outcomes. Material type contributed significantly to variance in fracture force for the biomaterials studied. Norian CRS required the greatest mean fracture force (1385 N, SD+/-292 N), followed by Norian CRS Fast Set Putty (1143 N, SD+/-193 N). Mimix required a mean fracture force of 740 N, SD+/-79 N

Comparison of posterior capsule folds following intracapsular implantation of three types of intraocular lenses with different haptic design

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Ling-Lin Zhang

2018-04-01

Full Text Available AIM: To compare the incidence of posterior capsule folds among different types of intraocular lens(IOLto determine risk factors of posterior capsule folds. METHODS:It was a retrospective study. We collected the cases in which the patients underwent phacoemulsification(PHACOand IOL implantation and at least one of the three types of IOL was implanted, including 2-haptic 3-piece IOLs(HOYA PY60AD, 4-haptic 1-piece IOLs(Bausch & Lomb AO, 2-haptic 1-piece IOLs(AMO Tecnis ZCB00. The posterior capsule folds were measured using slit lamp microscope 2d after the surgery. Information of patient's age, gender, length of ocular axis, intraocular pressure, types of IOL were recorded. Posterior capsule fold risk indicators were identified by using logistic regression analysis. RESULTS: One hundred eighty-seven patients(242 eyeshad been collected, including 80 eyes implanted with HOYA PY60AD IOLs, 81 eyes implanted with Bausch & Lomb AO IOLs, 81 eyes implanted with AMO Tecnis ZCB00 IOLs. The incidence of posterior capsule folds of patients implanted with HOYA PY60AD IOLs was significantly higher than those of patients implanted with AMO Tecnis ZCB00 IOLs(56.3% vs 38.3%, P=0.027. While the incidence of patients implanted with Bausch & Lomb AO IOLs was significantly lower than those of patients implanted with AMO Tecnis ZCB00 IOLs(14.8% vs 38.3%, P=0.001. Multi-factor logistics regression analysis demonstrated that independent risk factors were type of IOLs and length of ocular axis. Compared with AMO Tecnis ZCB00 IOLs, using HOYA PY60AD IOLs increased the risk of posterior capsule folds \\〖P=0.020, OR(95%CI=2.145(1.129,4.073\\〗, while using Bausch & Lomb AO IOLs reduced the risk \\〖P=0.001, OR(95%CI=0.274(0.127, 0.591\\〗. Shorter ocular axis might increase the risk of posterior capsule folds \\〖P=0.012, OR(95%CI=0.669(0.489, 0.915\\〗. CONCLUSION: Haptic design should be an important consideration in IOL design. Compared with AMO Tecnis ZCB00 IOLs

Hydroxyapatite-silver nanoparticles coatings on porous polyurethane scaffold

International Nuclear Information System (INIS)

Ciobanu, Gabriela; Ilisei, Simona; Luca, Constantin

2014-01-01

The present paper is focused on a study regarding the possibility of obtaining hydroxyapatite-silver nanoparticle coatings on porous polyurethane scaffold. The method applied is based on a combined strategy involving hydroxyapatite biomimetic deposition on polyurethane surface using a Supersaturated Calcification Solution (SCS), combined with silver ions reduction and in-situ crystallization processes on hydroxyapatite-polyurethane surface by sample immersing in AgNO 3 solution. The morphology, composition and phase structure of the prepared samples were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. The data obtained show that a layer of hydroxyapatite was deposited on porous polyurethane support and the silver nanoparticles (average size 34.71 nm) were dispersed among and even on the hydroxyapatite crystals. Hydroxyapatite/polyurethane surface acts as a reducer and a stabilizing agent for silver ions. The surface plasmon resonance peak in UV-Vis absorption spectra showed an absorption maximum at 415 nm, indicating formation of silver nanoparticles. The hydroxyapatite-silver polyurethane scaffolds were tested against Staphylococcus aureus and Escherichia coli and the obtained data were indicative of good antibacterial properties of the materials. - Highlights: • The hydroxyapatite and silver nanoparticles were grown on the polyurethane scaffold • The hydroxyapatite/polyurethane acts as reducing agent, stabilizer and matrix for Ag • The samples were well characterized by SEM-EDX, XRD, XPS, UV-visible spectroscopy • The hydroxyapatite/silver polyurethane scaffold shows antibacterial property

Plasma Sprayed Hydroxyapatite Coatings: Influence of Spraying Power on Microstructure

International Nuclear Information System (INIS)

Mohd, S. M.; Abd, M. Z.; Abd, A. N.

2010-01-01

The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to enhance the bonding between the implant and bone in human body. The coating process was implemented at different spraying power for each spraying condition. The coatings formed from a rapid solidification of molten and partly molten particles that impact on the surface of substrate at high velocity and high temperature. The study was concentrated on different spraying power that is between 23 to 31 kW. The effect of different power on the coatings microstructure was investigated using scanning electron microscope (SEM) and phase composition was evaluated using X-ray diffraction (XRD) analysis. The coatings surface morphology showed distribution of molten, partially melted particles and some micro-cracks. The produced coatings were found to be porous as observed from the cross-sectional morphology. The coatings XRD results indicated the presence of crystalline phase of HA and each of the patterns was similar to the initial powder. Regardless of different spraying power, all the coatings were having similar XRD patterns.

Preparation and corrosion resistance of magnesium phytic acid/hydroxyapatite composite coatings on biodegradable AZ31 magnesium alloy.

Science.gov (United States)

Zhang, Min; Cai, Shu; Zhang, Feiyang; Xu, Guohua; Wang, Fengwu; Yu, Nian; Wu, Xiaodong

2017-06-01

In this work, a magnesium phytic acid/hydroxyapatite composite coating was successfully prepared on AZ31 magnesium alloy substrate by chemical conversion deposition technology with the aim of improving its corrosion resistance and bioactivity. The influence of hydroxyapatite (HA) content on the microstructure and corrosion resistance of the coatings was investigated. The results showed that with the increase of HA content in phytic acid solution, the cracks on the surface of the coatings gradually reduced, which subsequently improved the corrosion resistance of these coated magnesium alloy. Electrochemical measurements in simulated body fluid (SBF) revealed that the composite coating with 45 wt.% HA addition exhibited superior surface integrity and significantly improved corrosion resistance compared with the single phytic acid conversion coating. The results of the immersion test in SBF showed that the composite coating could provide more effective protection for magnesium alloy substrate than that of the single phytic acid coating and showed good bioactivity. Magnesium phytic acid/hydroxyapatite composite, with the desired bioactivity, can be synthesized through chemical conversion deposition technology as protective coatings for surface modification of the biodegradable magnesium alloy implants. The design idea of the new type of biomaterial is belong to the concept of "third generation biomaterial". Corrosion behavior and bioactivity of coated magnesium alloy are the key issues during implantation. In this study, preparation and corrosion behavior of magnesium phytic acid/hydroxyapatite composite coatings on magnesium alloy were studied. The basic findings and significance of this paper are as follows: 1. A novel environmentally friendly, homogenous and crack-free magnesium phytic acid/hydroxyapatite composite coating was fabricated on AZ31 magnesium alloy via chemical conversion deposition technology with the aim of enhancing its corrosion resistance and

Preparation and characterization of chitosan-silver/hydroxyapatite composite coatings onTiO{sub 2} nanotube for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Yan, Yajing [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhang, Xuejiao [Medical Informatics, Hebei North University, Zhangjiakou 075000 (China); Li, Caixia [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Huang, Yong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); College of Lab Medicine, Hebei North University, Zhangjiakou 075000 (China); Ding, Qiongqiong [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China); Pang, Xiaofeng, E-mail: xfpang@aliyun.com [Institute of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2015-03-30

Highlights: • Chitosan/silver-doped hydroxyapatite biocomposite coating was successfully deposited on anodized Ti by electrochemical deposition. • The chemical state of silver in the synthesized coatings was studied by XPS peak deconvolution. • The synthesized coatings have excellent antibacterial activity because of synergistic effect of the Ag and CS. • The CSAgHAp coatings showed good biocompatibility and no adverse effect in cell culture tests. - Abstract: A biocomposite coating containing chitosan, silver, and hydroxyapatite was developed on anodized titanium substrate by electrochemical deposition. Coatings were characterized by field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and polarisation studies. Results showed that the prepared coatings had compact and dense morphology with a thickness of 6.2 ± 0.7 μm and that silver was evenly distributed. Testing the prepared coatings with Gram-positive and Gram-negative bacterial strains exhibited antibacterial activity because of the synergistic effect of silver and chitosan. The prepared coatings were also found to be nontoxic to MC3T3-E1 cells. These results suggested that chitosan/silver-hydroxyapatite biocomposite coatings can prevent the bacterial infection of implants.

Spectral analysis of allogeneic hydroxyapatite powders

Science.gov (United States)

Timchenko, P. E.; Timchenko, E. V.; Pisareva, E. V.; Vlasov, M. Yu; Red'kin, N. A.; Frolov, O. O.

2017-01-01

In this paper we discuss the application of Raman spectroscopy to the in vitro analysis of the hydroxyapatite powder samples produced from different types of animal bone tissue during demineralization process at various acid concentrations and exposure durations. The derivation of the Raman spectrum of hydroxyapatite is attempted by the analysis of the pure powders of its known constituents. Were experimentally found spectral features of hydroxyapatite, based on analysis of the line amplitude at wave numbers 950-965 cm-1 ((PO4)3- (ν1) vibration) and 1065-1075 cm-1 ((CO3)2-(ν1) B-type replacement). Control of physicochemical properties of hydroxyapatite was carried out by Raman spectroscopy. Research results are compared with an infrared Fourier spectroscopy.

Spectral analysis of allogeneic hydroxyapatite powders

International Nuclear Information System (INIS)

Timchenko, P E; Timchenko, E V; Pisareva, E V; Vlasov, M Yu; Red’kin, N A; Frolov, O O

2017-01-01

In this paper we discuss the application of Raman spectroscopy to the in vitro analysis of the hydroxyapatite powder samples produced from different types of animal bone tissue during demineralization process at various acid concentrations and exposure durations. The derivation of the Raman spectrum of hydroxyapatite is attempted by the analysis of the pure powders of its known constituents. Were experimentally found spectral features of hydroxyapatite, based on analysis of the line amplitude at wave numbers 950-965 cm -1 ((PO 4 ) 3- (ν 1 ) vibration) and 1065-1075 cm -1 ((CO 3 ) 2- (ν 1 ) B-type replacement). Control of physicochemical properties of hydroxyapatite was carried out by Raman spectroscopy. Research results are compared with an infrared Fourier spectroscopy. (paper)

Compressive and swelling behavior of cuttlebone derived hydroxyapatite loaded PVA hydrogel implants for articular cartilage

Science.gov (United States)

Kumar, B. Y. Santosh; Kumar, G. C. Mohan; Isloor, Arun M.

2018-04-01

Developing a novel antibacterial, nontoxic and biocompatible hydrogel with superior physio mechanical properties is still becoming a challenge. Herein, we synthesize hydroxyapatite (HA) powder from cuttlefish bone and prepare a series of stiff, tough, high strength, biocompatible hydrogel reinforced with HA by integrating glutaraldehyde into PVA/HA. Powder was characterized by SEM and XRD. Compressive strength and swelling properties are studied and compare the results with the properties of healthy natural articular cartilage.

Diode λ830nm laser associated with hydroxyapatite and biological membranes: bone repair in rats

Science.gov (United States)

Carneiro, Vanda S. M.; Limeira, Francisco d. A.; Gerbi, Marleny E. M.; Menezes, Rebeca F. d.; Santos-Neto, Alexandrino P. d.; Araújo, Natália C.

2016-02-01

The aim of the present study was to histologically assess the effect of laser therapy (AsGaAl, 830nm, 40mW, CW, φ ~0,6mm, 16J/cm2 per session, four points of 4J/cm2) on the repair of surgical defects created in the femur of Wistar rats. Background data: Several techniques have been proposed for the correction of bone defects, including the use of grafts and membranes. Despite the increase in the use of laser therapy for the biomodulation of bone repair, very few studies have assessed the associations between laser light and biomaterials. Method: The defects were filled with synthetic micro granular hydroxyapatite (HA) Gen-phos® implants and associated with bovine bone membranes (Gen-derm®). Surgical bone defects were created in 48 rats and divided into four groups: Group IA (control, n=12); Group IB (laser, n=12); Group IIA (HA + membrane, n=12); Group IIB (HA + membrane + laser, n=12). The irradiated groups received the first irradiation immediately after surgery. This radiation was then repeated seven times every 48h. The animals were sacrificed after 15, 21, and 30 days. Results: When comparing the groups irradiated with implants and membranes, it was found that the repair of the defects submitted to laser therapy occurred more quickly, starting 15 and 21 days after surgery. By the 30th day, the level of repair of the defects was similar in the irradiated and the non-irradiated groups. New bone formation was confirmed inside the cavity by the implant's osteoconduction. In the irradiated groups, there was an increment of this new bone formation. Conclusions: In conclusion, the use of laser therapy, particularly when associated with hydroxyapatite and biological membranes, produced a positive biomodulation effect on the healing process of bone defects on the femurs of rats.

Osteogenic protein 1 device increases bone formation and bone graft resorption around cementless implants

DEFF Research Database (Denmark)

Jensen, Thomas B; Overgaard, Søren; Lind, Martin

2002-01-01

In each femoral condyle of 8 Labrador dogs, a non weight-bearing hydroxyapatite-coated implant was inserted surrounded by a 3 mm gap. Each gap was filled with bone allograft or ProOsteon with or without OP-1 delivered in a bovine collagen type I carrier (OP-1 device). 300 microg OP-1 was used...

Hydroxyapatite synthesis on solid surfaces using a biological approach

International Nuclear Information System (INIS)

Wang, A; Mei, J; Tse, Y Y; Jones, I P; Sammons, R L

2012-01-01

Many naturally occurring mineralisation processes yield hydroxyapatite (HA) or related salts, but biological routes to calcification have not generally been exploited for production of hydroxyapatite for clinical and industrial applications. Serratia sp. NCIMB 40259 is a non-pathogenic Gram-negative bacterium which is capable of growing as a biofilm on many surfaces and can be used to form HA coatings on a variety of polymeric and metallic materials, including titanium. Here we review previous work and report the results of more recent studies on the influence of titanium compositional and surface properties on Serratia adherence and proliferation and biomineralisation on commercially pure titanium (cp Ti) discs and a Ti mesh. Bacterial adherence was equivalent on cpTi and Ti6Al4V, and biofilms formed on both rough and mirror-polished cpTi surfaces. Embedded alumina particles and alkali treatment did not noticeably alter the precipitation of Serratia HA, nor the structure of the coating in comparison with non-treated substrates. Coatings were retained after sintering at 800°C in argon, although the original curved plate-like crystals changed to nano-scale β-tricalcium phosphate particles. A phosphorous-rich diffusion zone formed at the coating-titanium interface. Bacterial mineralisation may have applications as a method for producing coatings on implants in non load-bearing sites, and non-clinical applications where a high surface area is the major concern.

Hydroxyapatite synthesis on solid surfaces using a biological approach

Science.gov (United States)

Wang, A.; Mei, J.; Tse, Y. Y.; Jones, I. P.; Sammons, R. L.

2012-12-01

Many naturally occurring mineralisation processes yield hydroxyapatite (HA) or related salts, but biological routes to calcification have not generally been exploited for production of hydroxyapatite for clinical and industrial applications. Serratia sp. NCIMB 40259 is a non-pathogenic Gram-negative bacterium which is capable of growing as a biofilm on many surfaces and can be used to form HA coatings on a variety of polymeric and metallic materials, including titanium. Here we review previous work and report the results of more recent studies on the influence of titanium compositional and surface properties on Serratia adherence and proliferation and biomineralisation on commercially pure titanium (cp Ti) discs and a Ti mesh. Bacterial adherence was equivalent on cpTi and Ti6Al4V, and biofilms formed on both rough and mirror-polished cpTi surfaces. Embedded alumina particles and alkali treatment did not noticeably alter the precipitation of Serratia HA, nor the structure of the coating in comparison with non-treated substrates. Coatings were retained after sintering at 800°C in argon, although the original curved plate-like crystals changed to nano-scale β-tricalcium phosphate particles. A phosphorous-rich diffusion zone formed at the coating-titanium interface. Bacterial mineralisation may have applications as a method for producing coatings on implants in non load-bearing sites, and non-clinical applications where a high surface area is the major concern.

Adsorption of nickel on synthetic hydroxyapatite from aqueous solutions

International Nuclear Information System (INIS)

Rosskopfova, O.; Galambos, M.; Pivarciova, L.; Rajec, P.; Caplovicova, M.

2013-01-01

The sorption of nickel on synthetic hydroxyapatite was investigated using a batch method and radiotracer technique. The hydroxyapatite samples used in experiments were a commercial hydroxyapatite and hydroxyapatite of high crystallinity with Ca/P ratio of 1.563 and 1.688, respectively, prepared by a wet precipitation process. The sorption of nickel on hydroxyapatite was pH independent ranging from 4.5 to 6.5 as a result of buffering properties of hydroxyapatite. The adsorption of nickel was rapid and the percentage of Ni sorption on both samples of hydroxyapatite was >98 % during the first 15-30 min of the contact time for initial Ni 2+ concentration of 1 x 10 -4 mol dm -3 . The experimental data for sorption of nickel have been interpreted in the term of Langmuir isotherm and the value of maximum sorption capacity of nickel on a commercial hydroxyapatite and hydroxyapatite prepared by wet precipitation process was calculated to be 0.184 and 0.247 mmol g -1 , respectively. The sorption of Ni 2+ ions was performed by ion-exchange with Ca 2+ cations on the crystal surface of hydroxyapatite under experimental conditions. The competition effect of Co 2+ and Fe 2+ towards Ni 2+ sorption was stronger than that of Ca 2+ ions. NH 4 + ions have no apparent effect on nickel sorption. (author)

Contemporary guided bone regeneration therapy for unaesthetic anterior peri-implantitis case

Directory of Open Access Journals (Sweden)

Benso Sulijaya

2016-12-01

Full Text Available Background: Dental implant is one of an alternative solutions reconstruction therapy for missing teeth. Complication of dental implant could occurs and leading to implant failure. In order to restore the complication, surgical treatment with guided bone regeneration (GBR is indicated. The potential use of bone substitutes is widely known to be able to regenerate the bone surrounding the implant and maintain bone volume. Purpose: The study aimed to demonstrate the effectiveness of implant-bone fully coverage by using sandwich technique of biphasic calcium phosphate (BCP and demineralized freeze-dried bone allografts (DFDBA bone substitutes combined with collagen resorbable membrane. Case: A 24-year-old male came with diagnosis of peri-implantitis on implant #11. Clinical finding indicated that implant thread was exposed on the labial aspect. Case management: After initial therapy including oral hygiene improvement performed, an operator did a contemporary GBR to correct the defect. Bone graft materials used were 40% β-tri calcium phosphate (β-TCP-60% hydroxyapatite (HA on the outer layer and DFDBA on the inner layer of the defect. Resorbable collagen membrane was used to cover the graft. Conclusion: GBR with sandwich technique could serve as one of the treatment choices for correcting an exposed anterior implant that would enhance the successful aesthetic outcome.

The fabrication of well-interconnected polycaprolactone/hydroxyapatite composite scaffolds, enhancing the exposure of hydroxyapatite using the wire-network molding technique.

Science.gov (United States)

Cho, Yong Sang; Hong, Myoung Wha; Jeong, Hoon-Jin; Lee, Seung-Jae; Kim, Young Yul; Cho, Young-Sam

2017-11-01

In this study, the fabrication method was proposed for the well-interconnected polycaprolactone/hydroxyapatite composite scaffold with exposed hydroxyapatite using modified WNM technique. To characterize well-interconnected scaffolds in terms of hydroxyapatite exposure, several assessments were performed as follows: morphology, mechanical property, wettability, calcium ion release, and cell response assessments. The results of these assessments were compared with those of control scaffolds which were fabricated by precision extruding deposition (PED) apparatus. The control PED scaffolds have interconnected pores with nonexposed hydroxyapatite. Consequently, cell attachment of proposed WNM scaffold was improved by increased hydrophilicity and surface roughness of scaffold surface resulting from the exposure of hydroxyapatite particles and fabrication process using powders. Moreover, cell proliferation and differentiation of WNM scaffold were increased, because the exposure of hydroxyapatite particles may enhance cell adhesion and calcium ion release. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2315-2325, 2017. © 2016 Wiley Periodicals, Inc.

Cluster bomb ocular injuries.

Science.gov (United States)

Mansour, Ahmad M; Hamade, Haya; Ghaddar, Ayman; Mokadem, Ahmad Samih; El Hajj Ali, Mohamad; Awwad, Shady

2012-01-01

To present the visual outcomes and ocular sequelae of victims of cluster bombs. This retrospective, multicenter case series of ocular injury due to cluster bombs was conducted for 3 years after the war in South Lebanon (July 2006). Data were gathered from the reports to the Information Management System for Mine Action. There were 308 victims of clusters bombs; 36 individuals were killed, of which 2 received ocular lacerations and; 272 individuals were injured with 18 receiving ocular injury. These 18 surviving individuals were assessed by the authors. Ocular injury occurred in 6.5% (20/308) of cluster bomb victims. Trauma to multiple organs occurred in 12 of 18 cases (67%) with ocular injury. Ocular findings included corneal or scleral lacerations (16 eyes), corneal foreign bodies (9 eyes), corneal decompensation (2 eyes), ruptured cataract (6 eyes), and intravitreal foreign bodies (10 eyes). The corneas of one patient had extreme attenuation of the endothelium. Ocular injury occurred in 6.5% of cluster bomb victims and 67% of the patients with ocular injury sustained trauma to multiple organs. Visual morbidity in civilians is an additional reason for a global ban on the use of cluster bombs.

Characterization of mechanical properties of hydroxyapatite-silicon-multi walled carbon nano tubes composite coatings synthesized by EPD on NiTi alloys for biomedical application.

Science.gov (United States)

Khalili, Vida; Khalil-Allafi, Jafar; Sengstock, Christina; Motemani, Yahya; Paulsen, Alexander; Frenzel, Jan; Eggeler, Gunther; Köller, Manfred

2016-06-01

Release of Ni(1+) ions from NiTi alloy into tissue environment, biological response on the surface of NiTi and the allergic reaction of atopic people towards Ni are challengeable issues for biomedical application. In this study, composite coatings of hydroxyapatite-silicon multi walled carbon nano-tubes with 20wt% Silicon and 1wt% multi walled carbon nano-tubes of HA were deposited on a NiTi substrate using electrophoretic methods. The SEM images of coated samples exhibit a continuous and compact morphology for hydroxyapatite-silicon and hydroxyapatite-silicon-multi walled carbon nano-tubes coatings. Nano-indentation analysis on different locations of coatings represents the highest elastic modulus (45.8GPa) for HA-Si-MWCNTs which is between the elastic modulus of NiTi substrate (66.5GPa) and bone tissue (≈30GPa). This results in decrease of stress gradient on coating-substrate-bone interfaces during performance. The results of nano-scratch analysis show the highest critical distance of delamination (2.5mm) and normal load before failure (837mN) as well as highest critical contact pressure for hydroxyapatite-silicon-multi walled carbon nano-tubes coating. The cell culture results show that human mesenchymal stem cells are able to adhere and proliferate on the pure hydroxyapatite and composite coatings. The presence of both silicon and multi walled carbon nano-tubes (CS3) in the hydroxyapatite coating induce more adherence of viable human mesenchymal stem cells in contrast to the HA coated samples with only silicon (CS2). These results make hydroxyapatite-silicon-multi walled carbon nano-tubes a promising composite coating for future bone implant application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route

Energy Technology Data Exchange (ETDEWEB)

Rodrigues da Silva, Gisele [Federal University of Sao Joao Del Rei, School of Pharmacy, Divinopolis, Minas Gerais (Brazil); Silva-Cunha, Armando da [Federal University of Minas Gerais, School of Pharmacy, Belo Horizonte, Minas Gerais (Brazil); Behar-Cohen, Francine [INSERM, Physiopathology of ocular diseases: Therapeutic innovations, Institut des Cordeliers, Paris (France); Laboratoire d' Innovations Therapeutiques, Fondation Rothschild, Paris (France); Universite Rene Descartes, Hotel Dieu University Hospital, Paris (France); Ayres, Eliane [Federal University of Minas Gerais, Department of Metallurgical and Materials Engineering, Belo Horizonte, Minas Gerais (Brazil); Orefice, Rodrigo L., E-mail: rorefice@demet.ufmg.br [Federal University of Minas Gerais, Department of Metallurgical and Materials Engineering, Belo Horizonte, Minas Gerais (Brazil)

2011-03-12

The treatment of posterior segment ocular diseases, such as uveitis, by using eye drops and oral drugs is usually not effective due to the body's natural barriers to drug penetration. In this study, ocular implants to treat uveitis were synthesized by incorporating dexamethasone acetate, an important type of corticoid used in the treatment of some uveitis, into a biodegradable polyurethane containi clay nanoparticles. Biodegradable polyurethane nanocomposites having poly(caprolactone) oligomers as soft segments were obtained by delaminating clay particles within a polyurethane aqueous dispersion. The drug was incorporated into the polymer by dispersing it in the waterborne polyurethane followed by a drying step. Nanoparticles derived from clay were demonstrated to be able to tailor the mechanical properties of polyurethanes to achieve values that can match the properties of ocular soft tissues. Infrared spectra (FTIR) showed that the presence of clay particles was able to change the microphase separation process typical of polyurethanes. X-ray diffraction and small angle x-ray scattering (SAXS) results were explored to show that the incorporation of both dexamethasone acetate and nanocomponents derived from clay led to a less defined two-phase polyurethane. The presence of clay nanoparticles increased the rate of drug release measured in vitro. Human retinal pigment epithelial cells (ARPE-19) were cultured in contact with polyurethanes and polyurethane nanocomposites, and the viability of them (evaluated by using MTT assay after 7 days) showed that no toxic components were released from polyurethanes containing no drugs during the test.

Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route

International Nuclear Information System (INIS)

Rodrigues da Silva, Gisele; Silva-Cunha, Armando da; Behar-Cohen, Francine; Ayres, Eliane; Orefice, Rodrigo L.

2011-01-01

The treatment of posterior segment ocular diseases, such as uveitis, by using eye drops and oral drugs is usually not effective due to the body's natural barriers to drug penetration. In this study, ocular implants to treat uveitis were synthesized by incorporating dexamethasone acetate, an important type of corticoid used in the treatment of some uveitis, into a biodegradable polyurethane containi clay nanoparticles. Biodegradable polyurethane nanocomposites having poly(caprolactone) oligomers as soft segments were obtained by delaminating clay particles within a polyurethane aqueous dispersion. The drug was incorporated into the polymer by dispersing it in the waterborne polyurethane followed by a drying step. Nanoparticles derived from clay were demonstrated to be able to tailor the mechanical properties of polyurethanes to achieve values that can match the properties of ocular soft tissues. Infrared spectra (FTIR) showed that the presence of clay particles was able to change the microphase separation process typical of polyurethanes. X-ray diffraction and small angle x-ray scattering (SAXS) results were explored to show that the incorporation of both dexamethasone acetate and nanocomponents derived from clay led to a less defined two-phase polyurethane. The presence of clay nanoparticles increased the rate of drug release measured in vitro. Human retinal pigment epithelial cells (ARPE-19) were cultured in contact with polyurethanes and polyurethane nanocomposites, and the viability of them (evaluated by using MTT assay after 7 days) showed that no toxic components were released from polyurethanes containing no drugs during the test.

Preparation and characterization of gelatin–hydroxyapatite composite microspheres for hard tissue repair

Energy Technology Data Exchange (ETDEWEB)

Chao, Shao Ching [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Department of Minimally Invasive Skull Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, 1650 Taiwan Boulevard, Sect. 4, Taichung, Taiwan (China); Department of Neurosurgery, ChangHua Hospital, Ministry of Health and Welfare, 80 Chung Cheng Road, Sect. 2 Chiu Kuan Village, Changhua 500, Taiwan (China); Wang, Ming-Jia; Pai, Nai-Su [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China); Yen, Shiow-Kang, E-mail: skyen@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan (China)

2015-12-01

Gelatin–hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO{sub 3}){sub 2}, NH{sub 4}H{sub 2}PO{sub 4} and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G–HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6–10 nm and tangle into porous microspheres after blending. The cell culture indicates that G–HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G–HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G–HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS. - Highlights: • G–HA composite microspheres were prepared by hydroxyapatite and gelatin. • In vitro tests indicated that the G–HA microspheres were biocompatible and bioactive. • In in vitro tests, G–HA microspheres could be applied in hard tissue engineering. • G–HA had healed the bone defect and provides a high proportion of surface area to open space.

Preliminary biocompatible evaluation of nano-hydroxyapatite/polyamide 66 composite porous membrane

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Yili Qu

2010-06-01

Full Text Available Yili Qu1,3, Ping Wang1,3, Yi Man1, Yubao Li2, Yi Zuo2, Jidong Li21State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610064, China; 2Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064, China; 3These authors contributed equally to this workAbstract: Nano-hydroxyapatite/polyamide 66 (nHA/PA66 composite with good bioactivity and osteoconductivity was employed to develop a novel porous membrane with asymmetric structure for guided bone regeneration (GBR. In order to test material cytotoxicity and to investigate surface-dependent responses of bone-forming cells, the morphology, proliferation, and cell cycle of bone marrow stromal cells (BMSCs of rats cultured on the prepared membrane were determined. The polygonal and fusiform shape of BMSCs was observed by scanning electronic microscopy (SEM. The proliferation of BMSCs cultured on nHA/PA66 membrane tested by the MTT method (MTT: [3-{4,5-dimethylthiazol-2yl}-2,5-diphenyl-2H-tetrazoliumbromide] was higher than that of negative control groups for 1 and 4 days’ incubation and had no significant difference for 7 and 11 days’ culture. The results of cell cycle also suggested that the membrane has no negative influence on cell division. The nHA/PA66 membranes were then implanted into subcutaneous sites of nine Sprague Dawley rats. The wounds and implant sites were free from suppuration and necrosis in all periods. All nHA/PA66 membranes were surrounded by a fibrous capsule with decreasing thickness 1 to 8 weeks postoperatively. In conclusion, the results of the in vitro and in vivo studies reveal that nHA/PA66 membrane has excellent biocompatibility and indicate its use in guided tissue regeneration (GTR or GBR.Keywords: hydroxyapatite/polyamide, barrier membrane, biocompatibility, guided bone regeneration

Study on carbonated hydroxyapatite as a thermoluminescence dosimeter

International Nuclear Information System (INIS)

Shafaei, M.; Sardari, D.; Ziaie, F.; Larijani, M.M.

2015-01-01

In this study, carbonated hydroxyapatite nanoparticles were used for thermoluminescence dosimetry. The nano-structure carbonated hydroxyapatite synthesized via hydrolysis of CaHPO 4 and CaCO 3 . The obtained nano powders were characterized by XRD technique and FTIR spectroscopy system. The carbonated hydroxyapatite samples were irradiated at different doses using 60 Co gamma rays, and were subjected to thermoluminescence measurement system, consequently. The TL glow curve exhibited two distinguishable peaks centered at around of 165 C and 310 C. The TL response of carbonated hydroxyapatite samples as a function of absorbed dose was linear in the range of 25-1000 Gy. Other dosimetric features of the carbonated hydroxyapatite nanoparticles including fading and reproducibility were also investigated.

Ocular TRUST: nationwide antimicrobial susceptibility patterns in ocular isolates.

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Asbell, Penny A; Colby, Kathryn A; Deng, Sophie; McDonnell, Peter; Meisler, David M; Raizman, Michael B; Sheppard, John D; Sahm, Daniel F

2008-06-01

Ocular Tracking Resistance in U.S. Today (TRUST) annually evaluates in vitro antimicrobial susceptibility of Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae to ciprofloxacin, gatifloxacin, levofloxacin, moxifloxacin, penicillin, azithromycin, tobramycin, trimethoprim, and polymyxin B in national samples of ocular isolates. Laboratory investigation. Prospectively collected ocular isolates (197 S. aureus, 49 S. pneumoniae, and 32 H. influenzae) from 35 institutions and archived ocular isolates (760 S. pneumoniae and 356 H. influenzae) from 34 institutions were tested by an independent, central laboratory. Mean minimum inhibitory concentrations that would inhibit growth of 90% of the tested isolates (MIC(90)) were interpreted as susceptible, intermediate, or resistant according to standardized breakpoints for systemic treatment. S. aureus isolates were classified as methicillin susceptible (MSSA) or methicillin resistant (MRSA). MSSA or MRSA susceptibility patterns were virtually identical for the fluoroquinolones, that is, MSSA susceptibility was 79.9% to 81.1% and MRSA susceptibility was 15.2%. Trimethoprim was the only agent tested with high activity against MRSA. All S. pneumoniae isolates were susceptible to gatifloxacin, levofloxacin, and moxifloxacin; 89.8% were susceptible to ciprofloxacin. H. influenzae isolates were 100% susceptible to all tested agents but trimethoprim. Ocular TRUST 1 data were consistent with the eight-year longitudinal sample of archived ocular isolates. The fluoroquinolones were consistently active in MSSA, S. pneumoniae, and H. influenzae. After more than a decade of intensive ciprofloxacin and levofloxacin use as systemic therapy, 100% of ocular S. pneumoniae isolates were susceptible to gatifloxacin, levofloxacin, and moxifloxacin; nonsusceptibility to ciprofloxacin was less than 15%. High-level in vitro MRSA resistance suggests the need to consider alternative therapy to fluoroquinolones when MRSA is a

Evaluation of hydroxyapatite-putty as a hemostatic agent

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Momota, Y.; Miyamoto, Y.; Takechi, M.; Yuasa, T.; Toh, T.; Nagayama, M. [Tokushima Univ. (Japan). First Dept. of Oral and Maxillofacial Surgery; Ishikawa, K.; Suzuki, K. [Okayama Univ. Dental School (Japan). Dept. of Biomaterials

2001-07-01

Although bone wax is often used as a hemostatic agent for bone in surgery, some problems in biocompatibility have been pointed out. Therefore, we have evaluated hydroxyapatite-putty (HAP-putty) as a hemostatic agent for bone. Adhesive strength of HAP-putty to bone increased with the amount of sodium alginate, reaching maximum value in case of containing 8% sodium alginate. An actual hemostatic ability of HAP-putty was evaluated using rabbits. Bleeding from bone was arrested within 3 minutes. Thus, HAP-putty showed excellent hemostatic ability. Soft tissue response to HAP-putty was evaluated in rabbit subcutaneous tissue. Histological observation revealed slight inflammatory response around HAP-putty. HAP-putty partially transformed to HAP 24 hours after the implantation. In conclusion, HAP-putty could be a useful hemostatic agent for bone due to its good hemostatic ability and excellent biocompatibility. (orig.)

OCULAR ASPECTS OF HYPERTHYROIDISM WITH SPECIAL REFERENCE TO OCULAR MYOPATHY

OpenAIRE

Mallika O. U; Suma Job

2017-01-01

BACKGROUND Hyperthyroidism can result in ocular manifestations even before systemic signs and symptoms develop. It is seen more in females and severe forms are more common in males. Early detection of ocular involvement can prevent vision threatening complications and troublesome discomforts affecting quality of vision. This clinical study highlights the importance of detailed ocular examination in hyperthyroidism. MATERIALS AND METHODS Fifty consecutive patients with ocu...

Synthetic Hydroxyapatite as a Biomimetic Oral Care Agent.

Science.gov (United States)

Enax, Joachim; Epple, Matthias

Human tooth enamel consists mostly of minerals, primarily hydroxyapatite, Ca10(PO4)6(OH)2, and thus synthetic hydroxyapatite can be used as a biomimetic oral care agent. This review describes the synthesis and characterization of hydroxyapatite from a chemist's perspective and provides an overview of its current use in oral care, with a focus on dentin hypersensitivity, caries, biofilm management, erosion, and enamel lesions. Reviews and original research papers published in English and German were included. The efficiency of synthetic hydroxyapatite in occluding open dentin tubules, resulting in a protection for sensitive teeth, has been well documented in a number of clinical studies. The first corresponding studies on caries, biofilm management and erosion have provided evidence for a positive effect of hydroxyapatite either as a main or synergistic agent in oral care products. However, more in situ and in vivo studies are needed due to the complexity of the oral milieu and to further clarify existing results. Due to its biocompatibility and similarity to biologically formed hydroxyapatite in natural tooth enamel, synthetic hydroxyapatite is a promising biomimetic oral care ingredient that may extend the scope of preventive dentistry.

Biodegradable Ceramics Consisting of Hydroxyapatite for Orthopaedic Implants

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Thomas K. Monsees

2017-11-01

Full Text Available This study aims to analyze hydroxyapatite (HAP coatings enriched with Mg and Ti prepared by a magnetron sputtering technique on Ti6Al4V substrate. For preparation of the coatings, three magnetron targets (HAP, MgO and TiO2 were simultaneously co-worked. The concentration of Mg added was varied by modifying the power applied to the MgO target. In all coatings, the Ti concentration was maintained constant by keeping the same cathode power fed during the whole deposition. The influence of different Mg dopant contents on the formation of phase, microstructure and morphology of the obtained Ti-doped HAP coatings were characterized by Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. Moreover, the effects of Mg addition upon corrosion, mechanical and biological properties were also investigated. Mg- and Ti-doped HAP coating obtained at low radio-frequency (RF power fed to the MgO target provided material with high corrosion resistance compared to other coatings and bare alloy. A slight decrease in hardness of the coatings was found after the Mg addition, from 8.8 to 5.7 GPa. Also, the values of elastic modulus were decreased from 87 to 53 GPa, this being an advantage for biomedical applications. The coatings with low Mg concentration proved to have good deformation to yielding and higher plastic properties. Biological test results showed that the novel surfaces exhibited excellent properties for the adhesion and growth of bone cells. Moreover, early adherent vital cell numbers were significantly higher on both coatings compared to Ti6Al4V, suggesting that Mg ions may accelerate initial osteoblast adhesion and proliferation.

Finite Element Simulation of Diametral Strength Test of Hydroxyapatite

International Nuclear Information System (INIS)

Ozturk, Fahrettin; Toros, Serkan; Evis, Zafer

2011-01-01

In this study, the diametral strength test of sintered hydroxyapatite was simulated by the finite element software, ABAQUS/Standard. Stress distributions on diametral test sample were determined. The effect of sintering temperature on stress distribution of hydroxyapatite was studied. It was concluded that high sintering temperatures did not reduce the stress on hydroxyapatite. It had a negative effect on stress distribution of hydroxyapatite after 1300 deg. C. In addition to the porosity, other factors (sintering temperature, presence of phases and the degree of crystallinity) affect the diametral strength of the hydroxyapatite.

Ocular lesions and experimental choline deficiency Lesiones oculares y deficiencia experimental de colina

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Georgina P. Ossani

2006-10-01

Full Text Available Previous studies have shown ocular haemorrhages in choline-deficient rats. The aim of this paper is to study further the relationship between ocular and renal lesions and biochemical alterations in rats fed a choline-deficient diet. Fifty one weanling male Wistar rats, were divided into two groups. Thirty one of them were fed a choline-deficient diet and the rest was fed a choline-supplemented diet ad libitum. Animals from both groups were killed between the fifth and the eighth day. Urea, creatinine and homocysteine concentrations in blood were determined. Eyes were used for light microscopy study; high resolution light microscopy and the study of the retina as "rétine a plat". Kidneys were studied by light microscopy. Choline-supplemented rats did not show ocular or renal lesion. Choline-deficient rats that showed renal lesions, tubular or cortical necrosis, did not always have ocular changes. There were no ocular changes in the only choline-deficient rat without renal lesion. The ocular changes consisted mainly in haemorrhage in both cameras and ciliary and vitreous bodies. Correlations between ocular and renal lesion (r=0.72, pEstudios previos han demostrado hemorragia ocular en ratas deficientes en colina. El objetivo de este trabajo es profundizar en la relación entre las alteraciones oculares, renales y bioquímicas en ratas deficientes en colina. Cincuenta y una ratas Wistar macho recién destetadas fueron divididas en dos grupos: treinta y una fueron alimentadas con una dieta colino deficiente y el resto con colina suplementada ad-libitum. Los animales de ambos grupos fueron sacrificados entre el quinto y el octavo día. Se midió la concentración de urea, creatinina y homocisteína en sangre. Los ojos fueron estudiados por microscopía de luz, microscopía óptica de alta resolución y para el estudio de la retina como retina plana. Los riñones fueron estudiados por microscopía de luz. Las ratas suplementadas con colina no

In Vivo Bone Formation Within Engineered Hydroxyapatite Scaffolds in a Sheep Model.

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Lovati, A B; Lopa, S; Recordati, C; Talò, G; Turrisi, C; Bottagisio, M; Losa, M; Scanziani, E; Moretti, M

2016-08-01

Large bone defects still represent a major burden in orthopedics, requiring bone-graft implantation to promote the bone repair. Along with autografts that currently represent the gold standard for complicated fracture repair, the bone tissue engineering offers a promising alternative strategy combining bone-graft substitutes with osteoprogenitor cells able to support the bone tissue ingrowth within the implant. Hence, the optimization of cell loading and distribution within osteoconductive scaffolds is mandatory to support a successful bone formation within the scaffold pores. With this purpose, we engineered constructs by seeding and culturing autologous, osteodifferentiated bone marrow mesenchymal stem cells within hydroxyapatite (HA)-based grafts by means of a perfusion bioreactor to enhance the in vivo implant-bone osseointegration in an ovine model. Specifically, we compared the engineered constructs in two different anatomical bone sites, tibia, and femur, compared with cell-free or static cell-loaded scaffolds. After 2 and 4 months, the bone formation and the scaffold osseointegration were assessed by micro-CT and histological analyses. The results demonstrated the capability of the acellular HA-based grafts to determine an implant-bone osseointegration similar to that of statically or dynamically cultured grafts. Our study demonstrated that the tibia is characterized by a lower bone repair capability compared to femur, in which the contribution of transplanted cells is not crucial to enhance the bone-implant osseointegration. Indeed, only in tibia, the dynamic cell-loaded implants performed slightly better than the cell-free or static cell-loaded grafts, indicating that this is a valid approach to sustain the bone deposition and osseointegration in disadvantaged anatomical sites.

Evaluation in vitro and in vivo of biomimetic hydroxyapatite coated on titanium dental implants

International Nuclear Information System (INIS)

Rigo, E.C.S.; Boschi, A.O.; Yoshimoto, M.; Allegrini, S.; Konig, B.; Carbonari, M.J.

2004-01-01

Among several materials used as dental implants, metals present relatively high tensile strengths. Although metals are biotolerable, they do not adhere to bone tissues. On the other hand, bioactive ceramics are known to chemically bind to bone tissues, but they are not enough mechanically resistant to tension stresses. To overcome this drawback, biotolerable metals can be coated with bioactive ceramics. Various methods can be employed for coating ceramic layers on metal substrates, among them ion sputtering, plasma spray, sol-gel, electrodeposition and a biomimetic process [E.C.S. Rigo, L.C. Oliveira, L.A. Santos, A.O. Boschi, R.G. Carrodeguas. Implantes metalicos recobertos com hidroxiapatita. Revista de Engenharia Biomedica, vol. 15 (1999), numeros 1-2, 21-29. Rio de Janeiro]. The aim of this work was to study the effect of the substitution of G glass, employed in the conventional biomimetic method during the nucleation stage, by a solution of sodium silicate (SS) on the chemical and morphological characteristics, and the adhesion of biomimetic coatings deposited on Ti implants. The obtained coatings were analyzed by diffuse reflectance FTIR spectroscopy (DRIFT) and scanning electron microscopy (SEM). Titanium implants were immersed in synthetic body fluid (SBF) and SS. All implants were left inside an incubator at 37 deg. C for 7 days, followed by immersion in 1.5 SBF and taken back to the incubator for additional 6 days at 37 deg. C. The 1.5 SBF were refreshed every 2 days. At the end of the treatment, the implants were washed in distilled and deionized water and dried at room temperature. To check the osseointegration, titanium implants coated with biomimetic method were inserted in rabbit's tibia, remaining there for 8 weeks. During the healing period, polyfluorochrome sequential labeling was inoculated in the rabbits to determine the period of bone remodeling. Results from DRIFT and SEM showed that, for all processing variants employed, a HA coating was

Better early osteogenesis of electroconductive hydroxyapatite-calcium titanate composites in a rabbit animal model.

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Mallik, Prafulla Kumar; Basu, Bikramjit

2014-03-01

In view of the fact that bone healing can be enhanced due to external electric field application, it is important to assess the influence of the implant conductivity on the bone regeneration in vivo. To address this issue, this study reports the in vivo biocompatibility property of multistage spark plasma sintered hydroxyapatite (HA)-80 wt % calcium titanate (CaTiO3 ) composites and monolithic HA, which have widely different conductivity property (14 orders of magnitude difference). The ability of bone regeneration was assessed by implantation in cylindrical femoral bone defects of rabbit animal model for varying time period of 1, 4, and 12 weeks. The overall assessment of the histology results suggests that the progressive healing of bone defects around HA-80 wt % CaTiO3 is associated with a better efficacy with respect to (w.r.t) early stage neobone formation, which is histomorphometrically around 140% higher than monolithic HA. Overall, this study demonstrates that the in vivo biocompatibility property of HA-80 wt % CaTiO3 with respect to local effects after 12 weeks of implantation is not compromised both qualitatively and quantitatively, and a comparison with control implant (HA) points toward the critical role of electrical conductivity on better early stage bone regeneration. Copyright © 2013 Wiley Periodicals, Inc.

Investigating the addition of SiO₂-CaO-ZnO-Na₂O-TiO₂ bioactive glass to hydroxyapatite: Characterization, mechanical properties and bioactivity.

Science.gov (United States)

Yatongchai, Chokchai; Placek, Lana M; Curran, Declan J; Towler, Mark R; Wren, Anthony W

2015-11-01

Hydroxyapatite (Ca10(PO4)6(OH)2) is widely investigated as an implantable material for hard tissue restoration due to its osteoconductive properties. However, hydroxyapatite in bulk form is limited as its mechanical properties are insufficient for load-bearing orthopedic applications. Attempts have been made to improve the mechanical properties of hydroxyapatite, by incorporating ceramic fillers, but the resultant composite materials require high sintering temperatures to facilitate densification, leading to the decomposition of hydroxyapatite into tricalcium phosphate, tetra-calcium phosphate and CaO phases. One method of improving the properties of hydroxyapatite is to incorporate bioactive glass particles as a second phase. These typically have lower softening points which could possibly facilitate sintering at lower temperatures. In this work, a bioactive glass (SiO2-CaO-ZnO-Na2O-TiO2) is incorporated (10, 20 and 30 wt%) into hydroxyapatite as a reinforcing phase. X-ray diffraction confirmed that no additional phases (other than hydroxyapatite) were formed at a sintering temperature of 560 ℃ with up to 30 wt% glass addition. The addition of the glass phase increased the % crystallinity and the relative density of the composites. The biaxial flexural strength increased to 36 MPa with glass addition, and there was no significant change in hardness as a function of maturation. The pH of the incubation media increased to pH 10 or 11 through glass addition, and ion release profiles determined that Si, Na and P were released from the composites. Calcium phosphate precipitation was encouraged in simulated body fluid with the incorporation of the bioactive glass phase, and cell culture testing in MC-3T3 osteoblasts determined that the composite materials did not significantly reduce cell viability. © The Author(s) 2015.

In vivo behavior of surface modified Ti6Al7Nb alloys used in selective laser melting for custom-made implants. A preliminary study.

Science.gov (United States)

Rotaru, H; Armencea, G; Spîrchez, Diana; Berce, C; Marcu, Teodora; Leordean, D; Kim, Seong Gon; Lee, Sang Woon; Dinu, C; Băciuţ, G; Băciuţ, Mihaela

2013-01-01

The objectives of this study were to test the biocompatibility and to evaluate the osseointegration of Titanium-Aluminum-Niobium (Ti6Al7Nb) alloy used in the manufacturing of personalized implants with selective laser melting (SLM) technology and to compare the growth viability of osteoblastic-like cells on different Ti6Al7Nb alloy samples (plain, coated with hydroxyapatite or SiO2-TiO2) implanted into the cranial bone of Wistar rats. In terms of biocompatibility, the cone-beam computer-tomography head scans taken at the moment of sacrifice of each group (one, two and three months) showed no implant displacement, no osteolysis and no liquid collection around the implants. At one month, around all types of implants new bone formation was noticed, although around the plain Ti6Al7Nb implant a large amount of powder debris was present. Still, no inflammatory reaction was seen. At two months, the distance between the implants and the calvarial bone margins diminished. A thin layer of fibrous tissue was noticed around the Ti6Al7Nb implant coated with hydroxyapatite but no bone contact was achieved. In the group sacrificed at three months there was still no bone contact, but noticeable were the SiO2-TiO2. In the group sacrificed at three months SiO2-TiO2 particles detached from the implant and completely integrated in the tissue were noticeable. All results suggested that the Ti6Al7Nb alloy with or without infiltration is well biologically tolerated.

Novel surface coating materials for endodontic dental implant

International Nuclear Information System (INIS)

Fathi, M.H.; Mortazavi, V.; Moosavi, S.B.

2003-01-01

The aim of this study was to design and produce novel coating materials in order to obtain two goals including; improvement of the corrosion behavior of metallic dental endodontic implant and the bone osteointegration simultaneously. Stainless steel 316L (SS) was used as a metallic substrate and a novel Hydroxyapatite/Titanium (HA/Ti) composite coating was prepared on it. Structural characterization techniques including XRD, SEM and EDX were utilized to investigate the microstructure and morphology of the coating. Electrochemical tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility. Two types of endodontic implants including; SS with and without (HA/Ti) composite coating were prepared and subsequently implanted in the mandibular canine of 20 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, osteointegration evaluation and histopathological interpretation was carried out using SEM and optical microscopy. Results indicate that the novel HA/Ti composite coating improves the corrosion behavior and biocompatibility of SS endodontic dental implant. The clinical evaluation (in vivo test) results showed that there was significant difference in osteointegration between coated and uncoated endodontic dental implants and average bone osteointegration of coated implants were more than uncoated implants. The histopathological results and bone tissue response to the coated implants was acceptable and it was concluded that HA/Ti composite coated SS could be used as well as an endodontic dental implant. (author)

Controlling the degradation rate of AZ91 magnesium alloy via sol–gel derived nanostructured hydroxyapatite coating

Energy Technology Data Exchange (ETDEWEB)

Rojaee, Ramin, E-mail: raminrojaee@aim.com [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Fathi, Mohammadhossein [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Raeissi, Keyvan [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

2013-10-15

Magnesium (Mg) alloys have been introduced as new generation of biodegradable orthopedic materials in recent years since it has been proved that Mg is one of the main minerals required for osseous tissue revival. The main goal of the present study was to establish a desired harmony between the necessities of orthopedic patient body to Mg{sup 2+} ions and degradation rate of the Mg based implants as a new class of biodegradable/bioresorbable materials. This prospect was followed by providing a sol–gel derived nanostructured hydroxyapatite (n-HAp) coating on AZ91 alloy using dip coating technique. Phase structural analysis, morphology study, microstructure characterization, and functional group identification were performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The prepared samples were immersed in simulated body fluid in order to study the formation of apatite-like precipitations, barricade properties of the n-HAp coating, and to estimate the dosage of released Mg{sup 2+} ions within a specified and limited time of implantation. Electrochemical polarization tests were carried out to evaluate and compare the corrosion behavior of the n-HAp coated and uncoated samples. The changes of the in vitro pH values were also evaluated. Results posed the noticeable capability of n-HAp coating on stabilizing alkalization behavior and improving the corrosion resistance of AZ91 alloy. It was concluded that n-HAp coated AZ91 alloy could be a good candidate as a type of biodegradable implant material for biomedical applications. - Highlights: • Nanostructured hydroxyapatite coatings were applied on Mg based alloy. • The whole corrosion process of Mg based alloy was controlled in body fluid. • This coating was able to act as a barrier against further release of Mg{sup 2+} ions. • The coating improved the stabilization of Mg alkalization behavior.

Controlling the degradation rate of AZ91 magnesium alloy via sol–gel derived nanostructured hydroxyapatite coating

International Nuclear Information System (INIS)

Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

2013-01-01

Magnesium (Mg) alloys have been introduced as new generation of biodegradable orthopedic materials in recent years since it has been proved that Mg is one of the main minerals required for osseous tissue revival. The main goal of the present study was to establish a desired harmony between the necessities of orthopedic patient body to Mg 2+ ions and degradation rate of the Mg based implants as a new class of biodegradable/bioresorbable materials. This prospect was followed by providing a sol–gel derived nanostructured hydroxyapatite (n-HAp) coating on AZ91 alloy using dip coating technique. Phase structural analysis, morphology study, microstructure characterization, and functional group identification were performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The prepared samples were immersed in simulated body fluid in order to study the formation of apatite-like precipitations, barricade properties of the n-HAp coating, and to estimate the dosage of released Mg 2+ ions within a specified and limited time of implantation. Electrochemical polarization tests were carried out to evaluate and compare the corrosion behavior of the n-HAp coated and uncoated samples. The changes of the in vitro pH values were also evaluated. Results posed the noticeable capability of n-HAp coating on stabilizing alkalization behavior and improving the corrosion resistance of AZ91 alloy. It was concluded that n-HAp coated AZ91 alloy could be a good candidate as a type of biodegradable implant material for biomedical applications. - Highlights: • Nanostructured hydroxyapatite coatings were applied on Mg based alloy. • The whole corrosion process of Mg based alloy was controlled in body fluid. • This coating was able to act as a barrier against further release of Mg 2+ ions. • The coating improved the stabilization of Mg alkalization behavior

INTERACTION OF BIOMATERIALS CONTAINING CALCIUM HYDROXYAPATITE/ POLY-L-LACTIDE WITH THE SIMULATED BODY FLUID

Directory of Open Access Journals (Sweden)

Marija Petković

2011-12-01

Full Text Available The purpose of biomaterials is to replace a part or a function of the body in a safe, physiologically and economically acceptable way. The process of the reconstruction of bone defects has always been a big problem in orthopedics and maxillofacial surgery. Since hydroxyapatite (HAp was detected as a component, the predominant constituent and the integral element of Mammalian bones, the development of the phospate ceramics as potential materials for implantation was enabled. This study investigated whether and in which way biomaterial calcium hydroxyapatite/poly-L-lactide (HAp/PLLA interacts with the ionic composition of the human plasma. The simulated body fluid (SBF is an artificial fluid that has the ionic composition and ionic concentration similar to the human blood plasma. HAp/PLLA was incubated for 1, 2, 3 and 5 weeks in SBF. The surfaces of both treated and untreated materials were analyzed on a scanning electron microscopy (SEM, and were also exposed to the energy dispersive X-ray spectroscopy (EDS, while SBF was submitted to the measuring of pH and electrical conductivity. However, our results indicate that the degradational changes of the material HAp/PLLA in SBF start from the surface of the treated material and that observed changes are the consequence of dissolution of its polymer component and the precipitation of the material similar to hydroxyapatite on its surface. This material shows good characteristics that place it among good candidates for the application in orthopedics and maxillofacial surgery.

Electrospun polyvinyl alcohol–collagen–hydroxyapatite nanofibers: a biomimetic extracellular matrix for osteoblastic cells

International Nuclear Information System (INIS)

Song Wei; Shi Tong; Ren Weiping; Markel, David C; Wang Sunxi; Mao Guangzhao

2012-01-01

The failure of prosthesis after total joint replacement is due to the lack of early implant osseointegration. In this study polyvinyl alcohol–collagen–hydroxyapatite (PVA-Col-HA) electrospun nanofibrous meshes were fabricated as a biomimetic bone-like extracellular matrix for the modification of orthopedic prosthetic surfaces. In order to reinforce the PVA nanofibers, HA nanorods and Type I collagen were incorporated into the nanofibers. We investigated the morphology, biodegradability, mechanical properties and biocompatibility of the prepared nanofibers. Our results showed these inorganic–organic blended nanofibers to be degradable in vitro. The encapsulated nano-HA and collagen interacted with the PVA content, reinforcing the hydrolytic resistance and mechanical properties of nanofibers that provided longer lasting stability. The encapsulated nano-HA and collagen also enhanced the adhesion and proliferation of murine bone cells (MC3T3) in vitro. We propose the PVA-Col-HA nanofibers might be promising modifying materials on implant surfaces for orthopedic applications. (paper)

Effect of Zn2+, Fe3+ and Cr3+ addition to hydroxyapatite for its application as an active constituent of sunscreens

Science.gov (United States)

de Araujo, T. S.; de Souza, S. O.; de Sousa, E. M. B.

2010-11-01

Biocompatible phosphate materials are used in different applications like bone and dental implants, drug delivery systems and others, but could also be applied in inorganic sunscreens. Using sunscreens is extremely necessary, because long time exposure to sun can cause skin cancer. In this work chemical precipitation method has been used to produce hydroxyapatite. Cr3+, Zn2+ and Fe3+ doped samples were characterized using powder X-Ray Diffraction (XRD) and Optical Absorption techniques. X-ray diffraction measurements confirmed the materials were in the expected crystalline structures. The crystallite size as measured from the X-ray pattern was 23-27 nm (±1). The absorption spectra in the ultraviolet and visible ranges indicate that appropriately doped and sized hydroxyapatite particles may have potential applications as active constituents of sunscreens.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: bonding to titanium and scanning electron microscopy.

Science.gov (United States)

Tredwin, Christopher J; Georgiou, George; Kim, Hae-Won; Knowles, Jonathan C

2013-05-01

Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) production has been characterised and optimised by the sol-gel method and the dissolution and biological properties of these materials were investigated. It was the objective of this study to investigate the potential bond strength and interaction of these materials with titanium. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the FHA and FA sol-gels. Using a spin coating technique the sol-gels were coated onto commercially pure titanium disks and crystallised at various temperatures. Using scanning electron microscopy (SEM) and elemental analysis, the surface characteristics, coating thickness and interaction of the Ti substrate and coating were investigated. The bond strengths of the coating to the Ti were investigated using an Instron Universal Load Testing Machine. Statistical analysis was performed with a two-way analysis of variance and post hoc testing with a Bonferroni correction. (1) Coating speed inversely influenced the coating thickness. (2) Increasing fluoride ion substitution and heating temperature significantly increased bond strength and (3) increasing fluoride ion substitution increased the coating thickness. FHA and FA synthesised using the sol-gel technique may offer a superior alternative to coating titanium implants with HA and plasma spraying. HA, FHA and FA materials synthesised by the sol-gel method may also have a use as bone grafting materials. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Effect of pores formation process and oxygen plasma treatment to hydroxyapatite formation on bioactive PEEK prepared by incorporation of precursor of apatite.

Science.gov (United States)

Yabutsuka, Takeshi; Fukushima, Keito; Hiruta, Tomoko; Takai, Shigeomi; Yao, Takeshi

2017-12-01

is an important factor to achieve high adhesive strength of hydroxyapatite layer to the PEEK substrate. This material is expected to be a candidate for next-generation implant materials with high bioactivity. Copyright © 2017 Elsevier B.V. All rights reserved.

X-linked ocular albinism in Blacks. Ocular albinism cum pigmento.

Science.gov (United States)

O'Donnell, F E; Green, W R; Fleischman, J A; Hambrick, G W

1978-07-01

X-linked ocular albinism can be an unsuspected cause of congenital nystagmus in blacks. In this study, eight of ten black ocular albinos from two kindreds had nonalbinotic, moderately pigmented fundi and no transillumination of the iris. We refer to this paradoxical condition as "ocular albinism cum pigmento." The only constant ophthalmoscopic feature was a foveal hypoplasia. Biopsy of clinically normal skin to demonstrate giant pigment granules is the most accurate means of diagnosis.

Bone Regeneration of Hydroxyapatite with Granular Form or Porous Scaffold in Canine Alveolar Sockets

Science.gov (United States)

JANG, SEOK JIN; KIM, SE EUN; HAN, TAE SUNG; SON, JUN SIK; KANG, SEONG SOO; CHOI, SEOK HWA

2017-01-01

This study was undertaken to assess bone regeneration using hydroxyapatite (HA). The primary focus was comparison of bone regeneration between granular HA (gHA) forms and porous HA (pHA) scaffold. The extracted canine alveolar sockets were divided with three groups: control, gHA and pHA. Osteogenic effect in the gHA and pHA groups showed bone-specific surface and bone mineral density to be significantly higher than that of the control group (psocket healing. For new bone formation during 8 weeks' post-implantation, HA with porous scaffold was superior to the granular form of HA. PMID:28438860

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.

Bone regeneration based on nano-hydroxyapatite and hydroxyapatite/chitosan nanocomposites: an in vitro and in vivo comparative study

International Nuclear Information System (INIS)

Tavakol, S.; Nikpour, M. R.; Amani, A.; Soltani, M.; Rabiee, S. M.; Rezayat, S. M.; Chen, P.; Jahanshahi, M.

2013-01-01

Surface morphology, surface wettability, and size distribution of biomaterials affect their in vitro and in vivo bone regeneration potential. Since nano-hydroxyapatite has a great chemical and structural similarity to natural bone and dental tissues, incorporated biomaterial of such products could improve bioactivity and bone bonding ability. In this research, nano-hydroxyapatite (23 ± 0.09 nm) and its composites with variety of chitosan content [2, 4, and 6 g (45 ± 0.19, 32 ± 0.12, and 28 ± 0.12 nm, respectively)] were prepared via an in situ hybridization route. Size distribution of the particles, protein adsorption, and calcium deposition of powders by the osteoblast cells, gene expression and percentage of new bone formation area were investigated. The highest degree of bone regeneration potential was observed in nano-hydroxyapatite powder, while the bone regeneration was lowest in nano-hydroxyapatite with 6 g of chitosan. Regarding these data, suitable size distribution next to size distribution of hydroxyapatite in bone, smaller size, higher wettability, lower surface roughness of the nano-hydroxyapatite particles and homogeneity in surface resulted in higher protein adsorption, cell differentiation and percentage of bone formation area. Results obtained from in vivo and in vitro tests confirmed the role of surface morphology, surface wettability, mean size and size distribution of biomaterial besides surface chemistry as a temporary bone substitute.

Hydroxyapatite-silver nanoparticles coatings on porous polyurethane scaffold.

Science.gov (United States)

Ciobanu, Gabriela; Ilisei, Simona; Luca, Constantin

2014-02-01

The present paper is focused on a study regarding the possibility of obtaining hydroxyapatite-silver nanoparticle coatings on porous polyurethane scaffold. The method applied is based on a combined strategy involving hydroxyapatite biomimetic deposition on polyurethane surface using a Supersaturated Calcification Solution (SCS), combined with silver ions reduction and in-situ crystallization processes on hydroxyapatite-polyurethane surface by sample immersing in AgNO3 solution. The morphology, composition and phase structure of the prepared samples were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. The data obtained show that a layer of hydroxyapatite was deposited on porous polyurethane support and the silver nanoparticles (average size 34.71 nm) were dispersed among and even on the hydroxyapatite crystals. Hydroxyapatite/polyurethane surface acts as a reducer and a stabilizing agent for silver ions. The surface plasmon resonance peak in UV-Vis absorption spectra showed an absorption maximum at 415 nm, indicating formation of silver nanoparticles. The hydroxyapatite-silver polyurethane scaffolds were tested against Staphylococcus aureus and Escherichia coli and the obtained data were indicative of good antibacterial properties of the materials. © 2013.

Effect of Zinc Oxide Addition on Antibacterial Behavior of Hydroxyapatite-Poly lactic-co-glycolic acid Scaffold for Bone Tissue Engineering Applications

Directory of Open Access Journals (Sweden)

Narges Abotalebi

2018-03-01

Full Text Available Introduction: Infection after the surgery is one of the problems of bone scaffolds implants which is normally treated by systemic administration of antibiotics. But due to the poor blood circulation in bone tissue, large antibiotic doses are needed which lead to further drawbacks to renal and hepatic systems. Material and method: In this study, the effect of zinc oxide addition on antibacterial behavior of hydroxyapatite- Poly lactic-co-glycolic acid scaffold was evaluated. The synthesized composite was characterized by X-ray diffraction, scanning electron microscopy equipped with elemental analysis and Fourier transform infrared spectra. In order to determine the antibacterial activity of the fabricated scaffold, Staphylococcus aureus (ATTC 25922 and Escherichia coli (ATTC 25923 were used as test microorganisms. Results: The results showed that Hydroxyapatite- Poly lactic-co-glycolic acid scaffold did not make inhibition zone in culture medium but the modification of Hydroxyapatite- Poly lactic-co-glycolic acid scaffold’s surface by zinc oxide particles caused Hydroxyapatite- Poly lactic-co-glycolic acid- zinc oxide scaffold to have antibacterial inhibition zone of 12 and 20 mm for Escherichia coli and Staphylococcus aureus, respectively. Discussion and conclusion: This study revealed that the addition of antibacterial agent to applicable bone tissue engineering scaffolds could be considered as an appropriate way to prevent the growth of infection at the scaffold site.

The Relationship Between Ocular Itch, Ocular Pain, and Dry Eye Symptoms (An American Ophthalmological Society Thesis).

Science.gov (United States)

Galor, Anat; Small, Leslie; Feuer, William; Levitt, Roy C; Sarantopoulos, Konstantinos D; Yosipovitch, Gil

2017-08-01

To evaluate associations between sensations of ocular itch and dry eye (DE) symptoms, including ocular pain, and DE signs. A cross-sectional study of 324 patients seen in the Miami Veterans Affairs eye clinic was performed. The evaluation consisted of questionnaires regarding ocular itch, DE symptoms, descriptors of neuropathic-like ocular pain (NOP), and evoked pain sensitivity testing on the forehead and forearm, followed by a comprehensive ocular surface examination including corneal mechanical sensitivity testing. Analyses were performed to examine for differences between those with and without subjective complaints of ocular itch. The mean age was 62 years with 92% being male. Symptoms of DE and NOP were more frequent in patients with moderate-severe ocular itch compared to those with no or mild ocular itch symptoms. With the exception of ocular surface inflammation (abnormal matrix metalloproteinase 9 testing) which was less common in those with moderate-severe ocular itch symptoms, DE signs were not related to ocular itch. Individuals with moderate-severe ocular itch also demonstrated greater sensitivity to evoked pain on the forearm and had higher non-ocular pain, depression, and post-traumatic stress disorders scores, compared to those with no or mild itch symptoms. Subjects with moderate-severe ocular itch symptoms have more severe symptoms of DE, NOP, non-ocular pain and demonstrate abnormal somatosensory testing in the form of increased sensitivity to evoked pain at a site remote from the eye, consistent with generalized hypersensitivity.

Surface modification of yttria stabilized zirconia via polydopamine inspired coating for hydroxyapatite biomineralization

Energy Technology Data Exchange (ETDEWEB)

Zain, Norhidayu Muhamad [Medical Devices and Technology Group, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Hussain, Rafaqat [Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Kadir, Mohammed Rafiq Abdul, E-mail: rafiq@biomedical.utm.my [Medical Devices and Technology Group, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia)

2014-12-15

Highlights: • Synthesis of functionalized yttria stabilized zirconia using polydopamine. • Improved hydrophilicity of the grafted samples with low contact angle of 44.0 ± 2.3. • Apatite layer with Ca/P ratio of 1.78 formed on the surface of the grafted samples. • Atomic percentage of Ca 2p increased by 2-fold at coating temperature of 37 °C. - Abstract: Yttria stabilized zirconia (YSZ) has been widely used as biomedical implant due to its high strength and enhanced toughening characteristics. However, YSZ is a bioinert material which constrains the formation of chemical bonds with bone tissue following implantation. Inspired by the property of mussels, the surface of YSZ ceramics was functionalized by quinone-rich polydopamine to facilitate the biomineralization of hydroxyapatite. YSZ discs were first immersed in 2 mg/mL of stirred or unstirred dopamine solution at either 25 or 37 °C. The samples were then incubated in 1.5 simulated body fluid (SBF) for 7d. The effect of coating temperature for stirred and unstirred dopamine solutions during substrate grafting was investigated on the basis of chemical compositions, wettability and biomineralization of hydroxyapatite on the YSZ functionalized surface. The results revealed that the YSZ substrate grafted at 37 °C in stirred solution of dopamine possessed significantly improved hydrophilicity (water contact angle of 44.0 ± 2.3) and apatite-mineralization ability (apatite ratio of 1.78). In summary, the coating temperature and stirring condition during grafting procedure affected the chemical compositions of the films and thus influenced the formation of apatite layer on the substrate during the biomineralization process.

Surface modification of yttria stabilized zirconia via polydopamine inspired coating for hydroxyapatite biomineralization

International Nuclear Information System (INIS)

Zain, Norhidayu Muhamad; Hussain, Rafaqat; Kadir, Mohammed Rafiq Abdul

2014-01-01

Highlights: • Synthesis of functionalized yttria stabilized zirconia using polydopamine. • Improved hydrophilicity of the grafted samples with low contact angle of 44.0 ± 2.3. • Apatite layer with Ca/P ratio of 1.78 formed on the surface of the grafted samples. • Atomic percentage of Ca 2p increased by 2-fold at coating temperature of 37 °C. - Abstract: Yttria stabilized zirconia (YSZ) has been widely used as biomedical implant due to its high strength and enhanced toughening characteristics. However, YSZ is a bioinert material which constrains the formation of chemical bonds with bone tissue following implantation. Inspired by the property of mussels, the surface of YSZ ceramics was functionalized by quinone-rich polydopamine to facilitate the biomineralization of hydroxyapatite. YSZ discs were first immersed in 2 mg/mL of stirred or unstirred dopamine solution at either 25 or 37 °C. The samples were then incubated in 1.5 simulated body fluid (SBF) for 7d. The effect of coating temperature for stirred and unstirred dopamine solutions during substrate grafting was investigated on the basis of chemical compositions, wettability and biomineralization of hydroxyapatite on the YSZ functionalized surface. The results revealed that the YSZ substrate grafted at 37 °C in stirred solution of dopamine possessed significantly improved hydrophilicity (water contact angle of 44.0 ± 2.3) and apatite-mineralization ability (apatite ratio of 1.78). In summary, the coating temperature and stirring condition during grafting procedure affected the chemical compositions of the films and thus influenced the formation of apatite layer on the substrate during the biomineralization process

Synthesis of nanocrystalline hydroxyapatite by using precipitation method

International Nuclear Information System (INIS)

Mobasherpour, I.; Heshajin, M. Soulati; Kazemzadeh, A.; Zakeri, M.

2007-01-01

In this investigation, hydroxyapatite powder has been synthesized from the calcium nitrate hydrated and di-ammonium hydrogen phosphate solution by precipitation method and heat treatment of hydroxyapatite powders. In order to study the structural evolution, the Fourier transform infrared spectroscopy (FTIR), the X-ray diffraction (XRD) and simultaneous thermal analysis (STA) were used. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to estimate the particle size of the powder and observe the morphology and agglomeration state of the powder. Results show that hydroxyapatite nanocrystalline can successfully be produced by precipitation technique from raw materials. Hydroxyapatite grain gradually increased in size when temperature increased from 100 to 1200 o C, and the hydroxyapatite hexagonal-dipyramidal phase was not transformed to the other calcium phosphates phases up to 1200 o C

Processing of hydroxyapatite obtained by combustion synthesis

International Nuclear Information System (INIS)

Canillas, M.; Rivero, R.; García-Carrodeguas, R.; Barba, F.; Rodríguez, M.A.

2017-01-01

One of the reasons of implants failure are the stress forces appearing in the material–tissue interface due to the differences between their mechanical properties. For this reason, similar mechanical properties to the surrounding tissue are desirable. The synthesis of hydroxyapatite by solution combustion method and its processing have been studied in order to obtain fully dense ceramic bodies with improved mechanical strength. Combustion synthesis provides nanostructured powders characterized by a high surface area to facilitate the following sintering. Moreover, synthesis was conducted in aqueous and oxidizing media. Oxidizing media improve homogenization and increase the energy released during combustion. It gives rise to particles whose morphology and size suggest lower surface energies compared with aqueous media. The obtained powders were sintered by using a controlled sintering rate schedule. Lower surfaces energies minimize the shrinkage during sintering and relative densities measurements and diametral compression test confirm improved densification and consequently mechanical properties. [es

Processing of hydroxyapatite obtained by combustion synthesis

Directory of Open Access Journals (Sweden)

M. Canillas

2017-09-01

Full Text Available One of the reasons of implants failure are the stress forces appearing in the material–tissue interface due to the differences between their mechanical properties. For this reason, similar mechanical properties to the surrounding tissue are desirable. The synthesis of hydroxyapatite by solution combustion method and its processing have been studied in order to obtain fully dense ceramic bodies with improved mechanical strength. Combustion synthesis provides nanostructured powders characterized by a high surface area to facilitate the following sintering. Moreover, synthesis was conducted in aqueous and oxidizing media. Oxidizing media improve homogenization and increase the energy released during combustion. It gives rise to particles whose morphology and size suggest lower surface energies compared with aqueous media. The obtained powders were sintered by using a controlled sintering rate schedule. Lower surfaces energies minimize the shrinkage during sintering and relative densities measurements and diametral compression test confirm improved densification and consequently mechanical properties.

Ocular Sarcoidosis

Science.gov (United States)

Pasadhika, Sirichai; Rosenbaum, James T

2015-01-01

Sarcoidosis is one of the leading causes of inflammatory eye disease. Ocular sarcoidosis can involve any part of the eye and its adnexal tissues, and may cause uveitis, episcleritis/scleritis, eyelid abnormalities, conjunctival granuloma, optic neuropathy, lacrimal gland enlargement and orbital inflammation. Glaucoma and cataract can be complications from inflammation itself or adverse effects from therapy. Ophthalmic manifestations can be isolated, or associated with other organ involvement. Patients with ocular sarcoidosis can present with a wide range of clinical presentations and severity. Multi-disciplinary approaches are required to achieve the best treatment outcomes for both ocular and systemic manifestations. PMID:26593141

Study of sorption processes of strontium on the synthetic hydroxyapatite

International Nuclear Information System (INIS)

Rosskopfova, O.; Galambos, M.; Rajec, P.

2011-01-01

The sorption of strontium on synthetic hydroxyapatite was investigated using batch method and radiotracer technique. The hydroxyapatite samples were prepared by a wet precipitation process followed by calcination of calcium phosphate that precipitated from aqueous solution. Also, commercial hydroxyapatites were used. The sorption of strontium on hydroxyapatite depended on the method of preparation and it was pH independent ranging from 4 to 9 as a result of buffering properties of hydroxyapatite. The distribution coefficient K d was significantly decreased with increasing concentration of Sr 2+ and Ca 2+ ions in solution with concentration above 1 x 10 -3 mol dm -3 . The percentage strontium sorption for commercial and by wet method prepared hydroxyapatite was in the range of 83-96%, while calcined hydroxyapatite was ranging from 10 to 30%. The experimental data for sorption of strontium have been interpreted in the term of Langmuir isotherm. The sorption of Sr 2+ ions was performed by ion-exchange with Ca 2+ cations on the crystal surface of hydroxyapatite. Although calcined hydroxyapatite is successfully used as biomaterial for hard tissues repair, it is not used for the treatment of liquid wastes. (author)

Sol-Gel Derived Hydroxyapatite Coating on Mg-3Zn Alloy for Orthopedic Application

Science.gov (United States)

Singh, Sanjay; Manoj Kumar, R.; Kuntal, Kishor Kumar; Gupta, Pallavi; Das, Snehashish; Jayaganthan, R.; Roy, Partha; Lahiri, Debrupa

2015-04-01

In recent years, magnesium and its alloys have gained a lot of interest as orthopedic implant constituents because their biodegradability and mechanical properties are closer to that of human bone. However, one major concern with Mg in orthopedics is its high corrosion rate that results in the reduction of mechanical integrity before healing the bone tissue. The current study evaluates the sol-gel-derived hydroxyapatite (HA) coating on a selected Mg alloy (Mg-3Zn) for decreasing the corrosion rate and increasing the bioactivity of the Mg surface. The mechanical integrity of the coating is established as a function of the surface roughness of the substrate and the sintering temperature of the coating. Coating on a substrate roughness of 15-20 nm and sintering at 400°C shows the mechanical properties in similar range of bone, thus making it suitable to avoid the stress-shielding effect. The hydroxyapatite coating on the Mg alloy surface also increases corrosion resistance very significantly by 40 times. Bone cells are also found proliferating better in the HA-coated surface. All these benefits together establish the candidature of sol-gel HA-coated Mg-3Zn alloy in orthopedic application.

Synthesis, characterization and cell behavior of fluoridated hydroxyapatite

Science.gov (United States)

Qu, Haibo

Fluorine-containing hydroxyapatite (Ca5(PO4) 3(OH)1-xFx FHA), where F- partially replaces OH- in hydroxyapatite (HA), is recognized as a possible biomaterial for bone and tooth implants and gaining attention in the last several years as a possible alternative to HA. In this study, FHA powders were synthesized through a pH-cycling method. It was discovered that fluorine incorporation increased with the fluorine content in the initial solution and the number of pH cycles employed. A relatively low fluorine incorporation efficiency, ˜60%, was attained for most of the FHA samples. The short time of stay at each pH cycle and the limited number of cycles used are believed to be the main reasons of the low fluorine incorporation into the apatite structure. It was also revealed that the FHA particles produced by the pH-cycling method were inhomogeneous. They were a mixture of hydroxyapatite and F-rich apatite (or FA) particles. The mechanisms of incorporation of fluorine ions into hydroxyapatite by a pH cyclicing method were studied using TEM, XRD and fluorine measurement. Instead of forming laminated structures as reported by other research groups, a mixture of nano-sized F-rich apatite (FHA) and hydroxyapatite (HA) particles were obtained using the pH-cyclicing method. After calcination, these FHA particles were homogenized and became single phased FHA. The effect of fluorine content, preparing method, and sintering temperature on both the bulk density and biaxial flexural strength of sintered FHA was studied. Both uniaxially pressed un-milled (UPU) and cold isostatically pressed milled (IPM) FHA discs were sintered at temperatures between 1200˜400°C at an interval of 100°C. It was found that the fluorine content had a significant impact on the sintering behavior, densification, and mechanical properties of FHA discs. A close correlation between the sintered density and biaxial flexural strength of the specimens was revealed, where the biaxial flexural strength

Resultados preliminares do implante de lente intra-ocular fácica artisan para correção de miopia Preliminary results of artisan phakic intraocular lens implantation to correct myopia

Directory of Open Access Journals (Sweden)

Leonardo Akaishi

2007-06-01

Full Text Available OBJETIVOS: Avaliar os resultados preliminares quanto à eficácia, estabilidade e segurança da lente intra-ocular de câmara anterior Artisan em olhos fácicos para correção de miopia. MÉTODOS: Foi analisado retrospectivamente o resultado de 34 olhos fácicos que receberam o implante de lente intra-ocular Artisan para correção de miopia. Os parâmetros avaliados foram: contagem endotelial pré e pós-operatória, acuidade visual sem correção pré e pós-operatória, melhor acuidade visual com correção pré e pós-operatória, equivalente esférico pré e pós-operatório, ganho e perda de linhas de visão e complicações. RESULTADOS: Dezoito pacientes (34 olhos foram incluídos neste estudo. Quatorze eram do sexo feminino (77,8% e 4 do sexo masculino. A idade média dos pacientes era de 30 anos (DP ± 7,3, variando de 21 a 46 anos. O período médio de seguimento foi de 8,5 meses (DP ± 3,6. A média de perda endotelial foi de 4,75% em 6 meses. A acuidade visual sem correção pré-operatória era de 0,02 (20/800 variando de 0,01 a 0,13. O equivalente esférico médio pré-operatório na refração dinâmica era de -13,25 D, variando de -5,75 D a -19,75 D. No último seguimento a acuidade visual sem correção era de 0,64 (20/32 variando de 0,33 a 1,00. O equivalente esférico médio na refração dinâmica era de -1,18 D (DP ± 0,92 variando de + 0,25 a -3,0. Entre as complicações observadas em nosso estudo 1 (3,4% paciente apresentou deslocamento da lente por trauma necessitando de uma segunda intervenção para reposicionamento. CONCLUSÃO: O uso de lente fácica de câmara anterior Artisan para correção de miopia no presente estudo se mostrou seguro, eficaz e com boa previsibilidade. No entanto, estudo prospectivo com maior número de casos e maior seguimento é necessário para determinar a segurança do procedimento a longo prazo.PURPOSE: To observe the preliminary results based on the efficacy, stability and safety of

Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study.

Science.gov (United States)

Chadda, Harshita; Naveen, Sangeetha Vasudevaraj; Mohan, Saktiswaren; Satapathy, Bhabani K; Ray, Alok R; Kamarul, Tunku

2016-07-01

Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail. The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination. Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software. Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis. The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Laser fabrication of Ag-HA nanocomposites on Ti6Al4V implant for enhancing bioactivity and antibacterial capability

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiangmei; Man, H.C., E-mail: mfhcman@polyu.edu.hk

2017-01-01

For titanium alloy implants, both surface bioactivity and antibacterial infection are the two critical factors in determining the success of clinical implantation of these metallic implants. In the present work, a novel nanocomposite layer of nano-silver-containing hydroxyapatite (Ag-HA) was prepared on the surface of biomedical Ti6Al4V by laser processing. Analysis using SEM, EDS and XRD shows the formation of an Ag-HA layer of about 200 μm fusion bonded to the substrate. Mineralization tests in simulated body fluid (SBF) showed that laser fabricated Ag-HA nanocomposite layer favors the deposition of apatite on the surface of the implants. Antibacterial tests confirmed that all Ag-HA nanocomposite layers can kill bacteria while a higher Ag content would lower the cytocompatibility of these coatings. Cell viability decreases when the Ag content reaches 5% in these coatings, due to the larger amount of Ag leached out, as confirmed by ion release evaluation. Our results reveal that laser fabricated Ag-HA nanocomposite coatings containing 2% Ag show both excellent cytocompatibility and antibacterial capability. - Highlights: • Silver-containing hydroxyapatite (Ag-HA) nanocomposite layer was fabricated on Ti6Al4V by laser technique. • Both bioactivity and antibacterial capability were significantly enhanced compared with bare Ti6Al4V. • Ag-HA nanocomposite coatings containing 2% Ag show both excellent cytocompatibility and antibacterial capability.

Electrochemical Evaluation of Hydroxyapatite/ZrN Coated Magnesium Biodegradable Alloy in Ringer Solution as a Simulated Body Fluid

OpenAIRE

Seyed Rahim Kiahosseini; Abdollah Afshar; Majid Mojtahedzadeh Larijani; Mardali Yousefpour

2015-01-01

Magnesium alloys as biodegradable materials can be used in body as an implant materials but since they have poor corrosion resistance, it is required to decrease their corrosion rate by biocompatible coatings. In this study, hydroxyapatite (HA) coatings in the presence of an intermediate layer of ZrN as a biocompatible material, deposited on AZ91 magnesium alloy by ion beam sputtering method at 300 °C temperature and at different times 180, 240, 300, 360 and 420 min. Then changes in corrosion...

The effects of bone marrow aspirate, bone graft, and collagen composites on fixation of titanium implants

DEFF Research Database (Denmark)

Babiker, Hassan; Ding, Ming; Sandri, Monica

2012-01-01

Replacement of extensive local bone loss especially in revision joint arthroplasty and spine fusion is a significant clinical challenge. Allograft and autograft have been considered as gold standards for bone replacement. However, there are several disadvantages such as donor site pain, bacterial...... contamination, and non union as well as the potential risk of disease transmission. Hydroxyapatite and collagen composites (HA/Collagen) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effects of newly developed HA/Collagen-composites with and without bone...... marrow aspirate (BMA) on enhancement of bone implant fixation. Method: Titanium alloy implants were inserted into bilateral femoral condyles of eight skeletally mature sheep, four implants per sheep. The implant had a circumferential gap of 2 mm. The gap was filled with: HA/Collagen; HA...

Synthesis and Characterization of Hydroxyapatite Powder by Wet Precipitation Method

Science.gov (United States)

Cahyaningrum, S. E.; Herdyastuty, N.; Devina, B.; Supangat, D.

2018-01-01

Hydroxyapatite is main inorganic component of the bone with formula Ca10(PO4)6(OH)2. Hydroxyapatite can be used as substituted bone biomaterial because biocompatible, non toxic, and osteoconductive. In this study, hydroxyapatite is synthesized using wet precipitation method from egg shell. The product was sintered at different temperatures of 800°C to 1000°C to improve its crystallinity. The hydroxyapatite was characterized by X-ray analysis, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) to reveal its phase content, morphology and types of bond present within it. The analytical results showed hydroxyapatite had range in crystallinity from 85.527 to 98.753%. The analytical functional groups showed that presence of functional groups such as OH, (PO4)3 2-, and CO3 2- that indicated as hydroxyapatite. The result of characterization SEM indicated that hydroxyapatite without sintering and HAp sintering at 800 °C were irregular shape without pore. The best hydroxyapatite with temperature sintering at 900 °C showed oval shaped with pores without agglomerated.

Vancomycin–chitosan composite deposited on post porous hydroxyapatite coated Ti6Al4V implant for drug controlled release

Energy Technology Data Exchange (ETDEWEB)

Yang, Chi-Chuan [Department of Materials Science and Engineering, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China); Lin, Chien-Chung [Department of Materials Science and Engineering, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China); Department of Orthopaedic Surgery, Taichung Armed Force General Hospital, 348, Sec. 2, Jhongshan Road, Taiping City, Taichung 411, Taiwan (China); Liao, Jiunn-Wang [Graduate Institute of Veterinary Pathobiology, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China); Yen, Shiow-Kang, E-mail: skyen@dragon.nchu.edu.tw [Department of Materials Science and Engineering, National Chung Hsing, University 250, Kuo-Kuang Road, Taichung 40227, Taiwan (China)

2013-05-01

Through the hydrogen bonds and the deprotonation, the vancomycin–chitosan composite has been originally deposited on Ti4Al4V by electrochemical technology. However, the rapid destruction of the hydrogen bonding between them by polar water molecules during immersion tests revealed 80% drug burst in a few hours. In this study, the post porous hydroxyapatite (HA) coated Ti4Al4V is prepared for the subsequent electrolytic deposition of vancomycin–chitosan composite to control the drug release. As expected, the initial burst is reduced to 55%, followed by a steady release about 20% from day 1 to day 5 and a slower release of the retained 25% after day 6, resulting in bacterial inhibition zone diameter of 30 mm which can last for more than a month in antibacterial tests, compared with the coated specimen without HA gradually loosing inhibition zone after 21 days. Besides, the cell culture indicates that the vancomycin–chitosan/HA composite coated has enhanced the proliferation, the differentiation and the mineralization of the osteoblast-like cell. In general, it is helpful for the osteointegration on permanent implants. Consistently, it effectively provides the prophylaxis and therapy of osteomyelitis according to the results of the rabbit infection animal model. - Highlights: ► The releasing curve of the vancomycin–chitosan/HA composite revealed three periods. ► The drug release sustained one month due to the effect of post porous HA coating. ► The composite coating could treat the osteomyelitis in the rabbit infection model.

Nanoscale Topographical Characterization of Orbital Implant Materials

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Marco Salerno

2018-04-01

Full Text Available The search for an ideal orbital implant is still ongoing in the field of ocular biomaterials. Major limitations of currently-available porous implants include the high cost along with a non-negligible risk of exposure and postoperative infection due to conjunctival abrasion. In the effort to develop better alternatives to the existing devices, two types of new glass-ceramic porous implants were fabricated by sponge replication, which is a relatively inexpensive method. Then, they were characterized by direct three-dimensional (3D contact probe mapping in real space by means of atomic force microscopy in order to assess their surface micro- and nano-features, which were quantitatively compared to those of the most commonly-used orbital implants. These silicate glass-ceramic materials exhibit a surface roughness in the range of a few hundred nanometers (Sq within 500–700 nm and topographical features comparable to those of clinically-used “gold-standard” alumina and polyethylene porous orbital implants. However, it was noted that both experimental and commercial non-porous implants were significantly smoother than all the porous ones. The results achieved in this work reveal that these porous glass-ceramic materials show promise for the intended application and encourage further investigation of their clinical suitability.

Miopatia ocular descendente

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Marcos R. G. de Freitas

1975-06-01

Full Text Available Os autores apresentam caso de paciente jovem, do sexo feminino, com afecção muscular primária ocular e faríngea sem caráter familial. Foram feitos estudos eletromiográficos e histopatológicos musculares que confirmam o caráter miogênico do processo. É feita comparação entre a miopatia ocular e a miopatia ocular descendente, acreditando os autores que seriam variantes

Qualidade de vida de pacientes pseudofácicos submetidos à cirurgia de catarata com implante de lente intra-ocular acomodativa Quality of life of pseudophakic patients with accommodative intraocular lens implant

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Filipe de Oliveira

2004-06-01

Full Text Available OBJETIVO: Avaliar a função visual e satisfação dos pacientes submetidos à cirurgia de catarata com implante de lente intra-ocular acomodativa e o impacto na sua qualidade de vida. MÉTODOS: Retrospectivamente, foram avaliados questionários aplicados após um ano da cirurgia de 22 pacientes que foram incluídos num estudo clínico para avaliar segurança e eficácia de uma lente intra-ocular de silicone de câmara posterior designada para corrigir visão para longe e perto. RESULTADOS: Do total dos pacientes operados, 16 (73% eram bilaterais e 6 (27% unilaterais, com idade média de 70,2 anos. Dos pacientes com implante unilateral, 5 (83,3% declararam melhora acentuada da visão e 1 (16,7% referiu máxima melhora. Quanto ao nível de satisfação, 5 (83,3% ficaram satisfeitos e 1 (16,7% muito satisfeito com o resultado cirúrgico. A visão noturna foi declarada como sem dificuldade por 3 (50,0%, pouca dificuldade por 2 (33,3% e dificuldade moderada por 1 (16,7%. No grupo bilateral, 7 (43,8% consideraram excelente a qualidade da visão para perto, 7 (43,8% muito boa, 1 (6,2% adequada e 1 (6,2% ruim. A visão intermediária foi classificada como excelente por 6 (37,5%, muito boa por 9 (56,3% e adequada por 1 (6,2%. A qualidade da visão para longe foi considerada excelente por 9 (56,3%, muito boa por 3 (43,8%, adequada por 2 (12,5% e não muito boa por 2 (12,5%. Em relação à visão noturna 9 (56,3% declararam não ter dificuldade alguma, 5 (31,2% pouca dificuldade e 2 (12,5% dificuldade moderada. CONCLUSÕES: Considerando a propriedade óptica da LIO, a maioria dos pacientes apresentou uma melhora considerável da função visual, sem a necessidade de correção óptica, e, portanto, com impacto positivo na qualidade de vida.PURPOSE: To evaluate the visual function and satisfaction of patients who underwent cataract surgery and were implanted with an accommodative intraocular lens and the impact in their quality of life. METHODS

Orbital implants: State-of-the-art review with emphasis on biomaterials and recent advances.

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Baino, Francesco; Potestio, Isabel

2016-12-01

In the treatment of severe oculo-orbital traumas, intraocular malignancies or other life-threatening conditions it is sometimes necessary to surgically remove the patient's diseased eye. Following the removal of the eye, an orbital implant is inserted into the anophthalmic socket in order to provide satisfactory volume replacement and restore the aesthetic appearance of a normal eye. Over the last decades, the implant design and the criteria of materials selection evolved from simple non-porous polymeric sphere to devices with more complex shape and functionalities for ensuring better clinical outcomes in the long-term. Polymeric and ceramic porous implants have gained prominence since their highly interconnected porous architecture allows them to act as a passive framework for fibrovascular in-growth offering reduced complication rates and the possibility of pegging to enhance the motility of the artificial eye. However, there are still drawbacks to these materials. Some critical aspects of today's orbital implants include the risk of migration and extrusion, postoperative infections and low motility transmitted to the aesthetic ocular prosthesis. Hence, the development of novel biomaterials with enhanced functionalities (e.g. angiogenesis, antibacterial effect, in situ mouldability) which enable an improved outcome of eye replacement is more than ever desirable and represents one of the most challenging topics of research in the field of ocular implants. This review summarizes the evolution of orbital implants and provides an overview of the most recent advances in the field as well as some critical remarks for materials design, selection, characterization and translation to clinical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting.

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Shuai, Cijun; Zhou, Yuanzhuo; Yang, Youwen; Feng, Pei; Liu, Long; He, Chongxian; Zhao, Mingchun; Yang, Sheng; Gao, Chengde; Wu, Ping

2017-03-17

Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA) was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

Systematic analysis of ocular trauma by a new proposed ocular trauma classification

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Bhartendu Shukla

2017-01-01

Full Text Available Purpose: The current classification of ocular trauma does not incorporate adnexal trauma, injuries that are attributable to a nonmechanical cause and destructive globe injuries. This study proposes a new classification system of ocular trauma which is broader-based to allow for the classification of a wider range of ocular injuries not covered by the current classification. Methods: A clinic-based cross-sectional study to validate the proposed classification. We analyzed 535 cases of ocular injury from January 1, 2012 to February 28, 2012 over a 4-year period in an eye hospital in central India using our proposed classification system and compared it with conventional classification. Results: The new classification system allowed for classification of all 535 cases of ocular injury. The conventional classification was only able to classify 364 of the 535 trauma cases. Injuries involving the adnexa, nonmechanical injuries and destructive globe injuries could not be classified by the conventional classification, thus missing about 33% of cases. Conclusions: Our classification system shows an improvement over existing ocular trauma classification as it allows for the classification of all type of ocular injuries and will allow for better and specific prognostication. This system has the potential to aid communication between physicians and result in better patient care. It can also provide a more authentic, wide spectrum of ocular injuries in correlation with etiology. By including adnexal injuries and nonmechanical injuries, we have been able to classify all 535 cases of trauma. Otherwise, about 30% of cases would have been excluded from the study.

Surface bioactivity modification of titanium by CO 2 plasma treatment and induction of hydroxyapatite: In vitro and in vivo studies

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Hu, Xixue; Shen, Hong; Shuai, Kegang; Zhang, Enwei; Bai, Yanjie; Cheng, Yan; Xiong, Xiaoling; Wang, Shenguo; Fang, Jing; Wei, Shicheng

2011-01-01

Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.

Comparação entre os resultados pós-operatórios de pacientes submetidos ao procedimento tríplice e transplante de córnea combinado a fixação secundária de lente intra-ocular Comparison between the postoperative results of triple procedure and combined penetrating keratoplasty/ transsclerally sutured posterior chamber lens implantation

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Daniela Maggioni Pereira Leão

2006-08-01

Full Text Available OBJETIVO: Comparar os resultados pós-operatórios de 2 grupos de pacientes submetidos a transplante de córnea com técnicas e tempo cirúrgico diferentes, em relação à abordagem do cristalino e/ou lente intra-ocular. MÉTODOS: Neste estudo retrospectivo foram analisados 37 olhos de pacientes divididos em 2 grupos: extração de catarata, implante de lentes intra-oculares (LIO e transplante de córnea no mesmo tempo cirúrgico - grupo 1 (G1 e extração de catarata sem implante de lentes intra-oculares no primeiro tempo cirúrgico e fixação secundária de lentes intra-oculares associada a transplante de córnea no segundo tempo cirúrgico - grupo 2 (G2. As variáveis estudadas foram: acuidade visual, pressão intra-ocular (PIO, astigmatismo refracional, astigmatismo ceratométrico e complicações pós-operatórias. RESULTADOS: Foi observado melhora da acuidade visual nos 2 grupos (G1 pPURPOSE: To compare the outcomes of two surgical techniques of penetrating keratoplasty with different surgical time, regarding the crystalline and the intraocular lens. METHODS: This retrospective study included 37 patients' eyes divided into 2 groups: extracapsular cataract extraction, posterior chamber intraocular lens implantation and penetrating keratoplasty (Group 1, G1 and transscleral fixation of posterior chamber lens and penetrating keratoplasty (Group 2, G2. The following parameters were recorded: visual acuity, intraocular pressure, refractive astigmatism, complication and keratometric astigmatism. RESULTS: Visual acuity improved in the two groups (G1 p<0.001 and G2 p=0.008. In G2 a significant change for the worse of intraocular pressure outcome was observed when compared with the other group (p=0.014. Regarding refractive and keratometric astigmatism no significant differences between the groups were found. The follow-up was 11 months. CONCLUSION: The most important negative prognostic factor affecting visual acuity was the postkeratoplasty

Ferroelectric Polarization in Nanocrystalline Hydroxyapatite Thin Films on Silicon

Science.gov (United States)

Lang, S. B.; Tofail, S. A. M.; Kholkin, A. L.; Wojtaś, M.; Gregor, M.; Gandhi, A. A.; Wang, Y.; Bauer, S.; Krause, M.; Plecenik, A.

2013-01-01

Hydroxyapatite nanocrystals in natural form are a major component of bone- a known piezoelectric material. Synthetic hydroxyapatite is widely used in bone grafts and prosthetic pyroelectric coatings as it binds strongly with natural bone. Nanocrystalline synthetic hydroxyapatite films have recently been found to exhibit strong piezoelectricity and pyroelectricity. While a spontaneous polarization in hydroxyapatite has been predicted since 2005, the reversibility of this polarization (i.e. ferroelectricity) requires experimental evidence. Here we use piezoresponse force microscopy to demonstrate that nanocrystalline hydroxyapatite indeed exhibits ferroelectricity: a reversal of polarization under an electrical field. This finding will strengthen investigations on the role of electrical polarization in biomineralization and bone-density related diseases. As hydroxyapatite is one of the most common biocompatible materials, our findings will also stimulate systematic exploration of lead and rare-metal free ferroelectric devices for potential applications in areas as diverse as in vivo and ex vivo energy harvesting, biosensing and electronics. PMID:23884324

Synthesis and characterization of praseodymium-142 hydroxyapatite (142Pr-HA)

International Nuclear Information System (INIS)

Duyeh Setiawan; Daud Nurhasan

2015-01-01

The use of radioisotope of lanthanide group with range of beta energy 0.4 - 2.2 MeV has been renewed interest in nuclear medicine. Praseodymium-142 radioisotope ( 142 Pr, t 1/2 = 19.2 hours, E β = 2.16 MeV) is suitable for applications radiotherapy. Labelled of the hydroxyapatite (Ca 10 (PO 4 )6(OH) 2 ) can be used as carrier of radionuclide after injection in the body injection. This research aim as a preliminary studies to make praseodymium-142 hydroxyapatite ( 142 Pr-HA) as a radiotherapy agent. The optimum condition of praseodymium-142 hydroxyapatite synthesis by controlling several parameters such as the pH and the weight of hydroxyapatite was obtained from process by used the nonradioactive praseodymium. The optimum condition of hydroxyapatite by praseodymium are at pH 5 and weight ratio praseodymium : hydroxyapatite is 1 : 16. The percentage of labeling hydroxyapatite with 142 PrCl 3 was 99.50% and the radiochemical purity of 142 Pr-Ha was 95.20%. (author)

Delivery of therapeutics for deep-seated ocular conditions - status quo.

Science.gov (United States)

Nguyen, Hubert; Eng, Shawn; Ngo, Thanh; Dass, Crispin R

2018-04-19

There is a need for research into designing effective pharmaceutical systems for delivering therapeutic drugs to the posterior of the eye for glaucoma-related pathology, macular degeneration, diabetic retinopathy, macular oedema, retinitis and choroiditis. Conventionally, eye drops have been extensively utilised for topical drug delivery to the anterior segment of the eye, but are less effective for delivery of therapeutics to the back of the eye due to significant barriers hampering drug penetration into the target intraocular tissue. This review explores some of the current and novel delivery systems employed to deliver therapeutics to the back of the eye such as those using liposomes, ocular implants, in situ gels, and nanoparticles, and how they can overcome some of these limitations. Issues such as blinking, precorneal fluid drainage, tear dilution and turnover, conjunctiva and nasal drug absorption, the corneal epithelium, vitreous drug clearance, and the blood-ocular barriers are reviewed and discussed. Further studies are needed to address their shortcomings such as drug compatibility and stability, economic viability and patient compliance. © 2018 Royal Pharmaceutical Society.

Ocular Straylight

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Sigrid Mueller-Schotte OD, MSc

2015-10-01

Full Text Available Intra-ocular straylight can cause decreased visual functioning, and it may cause diminished vision-related quality of life (VRQOL. This cross-sectional population-based study investigates the association between straylight and VRQOL in middle-aged and elderly individuals. Multivariable linear regression analyses were used to assess the association between straylight modeled continuously and cutoff at the recommended fitness-to-drive value, straylight ≥ 1.4 log(s, and VRQOL. The study showed that participants with normal straylight values, straylight ≤ 1.4 log(s, rated their VRQOL slightly better than those with high straylight values (straylight ≥ 1.4 log(s. Furthermore, multivariable regression analysis revealed a borderline statistical significant association ( p = .06 between intra-ocular straylight and self-reported VRQOL in middle-aged and elderly individuals. The association between straylight and self-reported VRQOL was not influenced by the status of the intra-ocular lens (natural vs. artificial intra-ocular lens after cataract extraction or the number of (instrumental activities of daily living that were reported as difficult for the elderly individuals.

Persistent fetal vasculature: ocular features, management of cataract and outcomes

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Marcia Beatriz Tartarella

2013-06-01

Full Text Available PURPOSES: To describe ocular features, management of cataract and functional outcomes in patients with persistent fetal vasculature. METHODS: Retrospective, descriptive case series of patients with persistent fetal vasculature. Data were recorded from the Congenital Cataract Section of Federal University of São Paulo, Brazil from 2001 to 2012. All patients were evaluated for sex, age at diagnosis, systemic findings, laterality, age at surgery, and initial and final follow-up visual acuities. Follow-up and complications after cataract surgery were recorded. Ultrasound was performed in all cases and ocular eco-Doppler was performed in most. RESULTS: The study comprised 53 eyes from 46 patients. Age at diagnosis ranged from 5 days of life to 10 years-old (mean 22.7 months. Twenty-seven patients were male (58.7%. Persistent fetal vasculature was bilateral in 7 patients (15.2%. Forty-two eyes (79.2% had combined (anterior and posterior forms PFV presentation, 5 eyes (9.4% had only anterior persistent fetal vasculature presentation and 6 eyes (11.3% had posterior persistent fetal vasculature presentation. Thirty-eight eyes (71.7% were submitted to cataract surgery. Lensectomy combined with anterior vitrectomy was performed in 18 eyes (47.4%. Phacoaspiration with intraocular lens implantation was performed in 15 eyes (39.5%, and without lens implantation in 5 eyes (13.2%. Mean follow-up after surgery was 44 months. Postoperative complications were posterior synechiae (3 cases, retinal detachment (2 cases, phthisis (3 cases, posterior capsular opacification (8 cases, inflammatory pupillary membrane (5 cases, glaucoma (4 cases, intraocular lens implantation displacement (1 case and vitreous hemorrhage (2 cases. Complications were identified in 19 (50% of the 38 operated eyes. Visual acuity improved after cataract surgery in 83% of the eyes. CONCLUSIONS: Patients with persistent fetal vasculature have variable clinical presentation. There is an

Sorption of technetium on composite chitosan-hydroxyapatite from aqueous solutions

International Nuclear Information System (INIS)

Pivarciova, L.; Rosskopfova, O.; Galambos, M.; Rajec, P.

2013-01-01

Biomaterials such as natural polymers (chitosan) and hydroxyapatite have an important application in material for bone replacement. Most of chitosan/hydroxyapatite composites are prepared by mixing hydroxyapatite particles with chitosan matrices. Another method of preparation of chitosan/hydroxyapatite composite is in-situ generation of nano-hydroxyapatite in chitosan matrix. The most common biomaterial used in the past years in hard tissue regeneration was hydroxyapatite, owing to its properties as biocompatibility, bioactivity, non-toxicity, non-immunogenicity etc. Chitosan is a polyaminosacharide, partially deacetylated product of chitin. Chitosan can be used in combination with other materials to enhance bone growth such as bone filling paste. The aims of this work were: the influence of the contact time on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of pH on sorption of pertechnate anions on chitosan/hydroxyapatite composites; the effect of foreign ions on sorption of pertechnate anions on chitosan/hydroxyapatite composites. The author concluded: the percentage of technetium sorption after 1 hour of contact time was > 97 %. In the initial pH range of 2.9-10.2, the percentage of technetium sorption on chitosan/hydroxyapatite composites CH/HA(A), CH/HA(B), CH/HA 30:70, ZCH was > 98 % and on CH/HA 50:50 was > 94%. The competition effect of Fe 2+ towards TcO 4 :- sorption is stronger than competition effect of other observed cations for all examined composites with the same weight ratio. The percentage of the technetium sorption was the same for all composites with the weight ratio of 30:70. (authors)

Mechanical properties of titanium-hydroxyapatite (Ti-HA) composite coating on stainless steel prepared by thermal spraying

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Rosmamuhamadani, R.; Azhar, N. H.; Talari, M. K.; Yahaya, Sabrina M.; Sulaiman, S.; Ismail, M. I. S.

2017-09-01

Addition of hydroxyapatite (HA) can enhance the bioactivity of the common metallic implant due to its similarity with natural bones and teeth. In this investigation, high velocity oxy-fuel (HVOFT) technique was used to deposit titanium-hydroxyapatite (Ti-HA) composite on stainless steel substrate plate with different percentage of HA for biomedical applications. The aim of this research is to investigate the mechanical properties of Ti-HA coating such as hardness, adhesion strength and wear behaviour. The hardness and strength was determined by using SHIMADZU-microhardness Vickers tester and PosiTest AT portable adhesion tester respectively. The wear test was performed by using pin-on-disk equipment and field emission scanning electron microscope (FESEM) used to determine the extent of surface damage. From the results obtained, mechanical properties such as hardness and adhesion strength of titanium (Ti) coating decreased with the increased of HA contents. Meanwhile, the coefficient of friction of Ti-10% HA coating shows the highest value compare to others as three-body abrasion had occurred during the test.

A novel electrospun silk fibroin/hydroxyapatite hybrid nanofibers

International Nuclear Information System (INIS)

Ming, Jinfa; Zuo, Baoqi

2012-01-01

A novel electrospinning of silk fibroin/hydroxyapatite hybrid nanofibers with different composition ratios was performed with methanoic acid as a spinning solvent. The silk fibroin/hydroxyapatite hybrids containing up to 30% hydroxyapatite nanoparticles could be electrospun into the continuous fibrous structure. The electrospun silk fibroin/hydroxyapatite hybrid nanofibers showed bigger diameter and wider diameter distribution than pure silk fibroin nanofibers, and the average diameter gradually increased from 95 to 582 nm. At the same time, the secondary structure of silk fibroin/hydroxyapatite nanofibers was characterized by X-ray diffraction, Fourier transform infrared analysis, and DSC measurement. Comparing with the pure silk fibroin nanofibers, the crystal structure of silk fibroin was mainly amorphous structure in the hybrid nanofibers. X-ray diffraction results demonstrated the hydroxyapatite crystalline nature remained as evidenced from the diffraction planes (002), (211), (300), and (202) of the hydroxyapatite crystallites, which was also confirmed by Fourier transform infrared analysis. The thermal behavior of hybrid nanofibers exhibited the endothermic peak of moisture evaporation ranging from 86 to 113 °C, and the degradation peak at 286 °C appeared. The SF/HAp nanofibers mats containing 30% HAp nanoparticles showed higher breaking tenacity and extension at break for 1.1688 ± 0.0398 MPa and 6.55 ± 1.95%, respectively. Therefore, the electrospun silk fibroin/hydroxyapatite hybrid nanofibers should be provided potentially useful options for the fabrication of biomaterial scaffolds for bone tissue engineering. -- Highlights: ► The novel SF/HAp nanofibers were directly prepared by electrospinning method. ► The nanofiber diameter had significant related to the content of HAp. ► The crystal structure of silk fibroin was mainly amorphous structure in the hybrid nanofibers. ► The HAp crystals existing in the hybrid nanofibers were characterized

Evaluating the effects of hydroxyapatite coating on the corrosion behavior of severely deformed 316Ti SS for surgical implants

International Nuclear Information System (INIS)

Mhaede, Mansour; Ahmed, Aymen; Wollmann, Manfred; Wagner, Lothar

2015-01-01

The present work investigates the effects of severe plastic deformation by cold rolling on the microstructure, the mechanical properties and the corrosion behavior of austenitic stainless steel (SS) 316Ti. Hydroxyapatite coating (HA) was applied on the deformed material to improve their corrosion resistance. The martensitic transformation due to cold rolling was recorded by X-ray diffraction spectra. The effects of cold rolling on the corrosion behavior were studied using potentiodynamic polarization. The electrochemical tests were carried out in Ringer's solution at 37 ± 1 °C. Cold rolling markedly enhanced the mechanical properties while the electrochemical tests referred to a lower corrosion resistance of the deformed material. The best combination of both high strength and good corrosion resistance was achieved after applying hydroxyapatite coating. - Highlights: • Cold rolling markedly increases the hardness of SS 316Ti from 125 to 460 HV10. • Higher deformation degrees lead to lower corrosion resistance. • Application of HA-coating leads to significant improvement of the corrosion resistance

Preparation and characterization of collagen-hydroxyapatite/pectin composite.

Science.gov (United States)

Wenpo, Feng; Gaofeng, Liang; Shuying, Feng; Yuanming, Qi; Keyong, Tang

2015-03-01

Pectin, a kind of plant polysaccharide, was introduced into collagen-hydroxyapatite composite system, and prepared collagen-hydroxyapatite/pectin (Col-HA/pectin) composite in situ. The structure of the composite was investigated by XRD, SEM, and FT-IR. The mechanical properties, water absorption, enzyme degradation, and cytotoxicity of the composite were investigated as well. The results show that the inorganic substance in the composite materials is hydroxyapatite in relatively low crystallinity. A new interface appeared by the interaction among hydroxyapatite and collagen-pectin, and formed smooth fine particles. The mechanical properties, water absorption, enzyme degradation, and cytotoxicity indicate a potential use in bone replacement for the new composite. Copyright © 2014 Elsevier B.V. All rights reserved.

Cadmium immobilization by hydroxyapatite

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Smičiklas Ivana D.

2003-01-01

Full Text Available The contamination of air, soil and water by cadmium is a great environmental problem. If cadmium occurs in nature in ionic form, soluble in water, it easily enters into the food chain. Hydroxyapatite (HAP, Ca-o(POAe(OH2 is a sparingly soluble salt and an excellent matrix for the removal of heavy metals from solutions. Considerable research attention has been paid to the bond between Cc/2+ ions and synthetic hydroxyapatite of known composition. The sorption mechanism is complex. The dominant process is ion exchange, but surface adsorption, surface complexation and coprecipitation can also contribute to the overall mechanism. The sorption capacity depends on the characteristics of hydroxyapatite itself and on the experimental conditions. Under optimum conditions a maximum capacity of 0.8 mol Cd2+/mol HAP can be achieved. HAP is a potential sorbent for the remediation of contaminated water and soil, for industrial waste treatment, and it is also referenced as a material that can be used as a barrier around waste depositories.

[Study on biocompatibility of hydroxyapatite/high density polyethylene (HA/HDPE) nano-composites artificial ossicle].

Science.gov (United States)

Wang, Guohui; Zhu, Shaihong; Tan, Guolin; Zhou, Kechao; Huang, Suping; Zhao, Yanzhong; Li, Zhiyou; Huang, Boyun

2008-06-01

This study was aimed to evaluate the biocompatibility of Hydroxyapatite/High density polyethylene (HA/ HDPE) nano-composites artificial ossicle. The percentage of S-period cells were detected by flow cytometry after L929 cells being incubated with extraction of the HA/HDPE nano-composites; the titanium materials for clinical application served as the contrast. In addition, both materials were implanted in animals and the histopathological evaluations were conducted. There were no statistically significant differences between the two groups (P >0.05). The results demonstrated that the HA/HDPE nano-composite artificial ossicle made by our laboratory is of a good biocompatibility and clinical application outlook.

Effects of cell-attachment and extracellular matrix on bone formation in vivo in collagen-hydroxyapatite scaffolds.

Science.gov (United States)

Villa, Max M; Wang, Liping; Rowe, David W; Wei, Mei

2014-01-01

Cell-based tissue engineering can be used to replace missing or damaged bone, but the optimal methods for delivering therapeutic cells to a bony defect have not yet been established. Using transgenic reporter cells as a donor source, two different collagen-hydroxyapatite (HA) scaffolds, and a critical-size calvarial defect model, we investigated the effect of a cell-attachment period prior to implantation, with or without an extracellular matrix-based seeding suspension, on cell engraftment and osteogenesis. When quantitatively compared, the in-house scaffold implanted immediately had a higher mean radiopacity than in-house scaffolds incubated overnight. Both scaffold types implanted immediately had significantly higher area fractions of donor cells, while the in-house collagen-HA scaffolds implanted immediately had higher area fractions of the mineralization label compared with groups incubated overnight. When the cell loading was compared in vitro for each delivery method using the in-house scaffold, immediate loading led to higher numbers of delivered cells. Immediate loading may be preferable in order to ensure robust bone formation in vivo. The use of a secondary ECM carrier improved the distribution of donor cells only when a pre-attachment period was applied. These results have improved our understanding of cell delivery to bony defects in the context of in vivo outcomes.

In situ deposition of hydroxyapatite on graphene nanosheets

International Nuclear Information System (INIS)

Neelgund, Gururaj M.; Oki, Aderemi; Luo, Zhiping

2013-01-01

Graphical abstract: A facile chemical precipitation method is reported for effective in situ deposition of hydroxyapatite on graphene nanosheets. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. Display Omitted Highlights: ► It is a facile and effective method for deposition of HA on GR nanosheets. ► It avoids the use of harmful reducing agents like hydrazine, NaBH 4 etc. ► GR nanosheets were produced using bio-compatible, ethylenediamine. ► The graphitic structure of synthesized GR nanosheets was high ordered. ► The ratio of Ca to P in HA was 1.64, which is close to ratio in natural bone. -- Abstract: Graphene nanosheets were effectively functionalized by in situ deposition of hydroxyapatite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

In situ deposition of hydroxyapatite on graphene nanosheets

Energy Technology Data Exchange (ETDEWEB)

Neelgund, Gururaj M. [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Oki, Aderemi, E-mail: aroki@pvamu.edu [Department of Chemistry, Prairie View A and M University, Prairie View, TX 77446 (United States); Luo, Zhiping [Microscopy and Imaging Center and Materials Science and Engineering Program, Texas A and M University, College Station, TX 77843 (United States)

2013-02-15

Graphical abstract: A facile chemical precipitation method is reported for effective in situ deposition of hydroxyapatite on graphene nanosheets. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. Display Omitted Highlights: ► It is a facile and effective method for deposition of HA on GR nanosheets. ► It avoids the use of harmful reducing agents like hydrazine, NaBH{sub 4} etc. ► GR nanosheets were produced using bio-compatible, ethylenediamine. ► The graphitic structure of synthesized GR nanosheets was high ordered. ► The ratio of Ca to P in HA was 1.64, which is close to ratio in natural bone. -- Abstract: Graphene nanosheets were effectively functionalized by in situ deposition of hydroxyapatite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

Electrochemical characterization of pulsed layer deposited hydroxyapatite-zirconia layers on Ti-21Nb-15Ta-6Zr alloy for biomedical application

Energy Technology Data Exchange (ETDEWEB)

Izquierdo, Javier [Department of Chemistry, Universidad de La Laguna, P.O. Box 456, E-38200 La Laguna, Tenerife (Spain); Bolat, Georgiana [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, 73 Prof. Dr. Doc. D. Mangeron Street, 700050 Iasi (Romania); Cimpoesu, Nicanor [“Gheorghe Asachi” Technical University of Iasi, Faculty of Materials Science, 61-63 Prof. Dr. Doc. D. Mangeron Street, 700050 Iasi (Romania); Trinca, Lucia Carmen [Science Department, University of Agricultural Sciences and Veterinary Medicine, M. Sadoveanu Alley 3, 700490 Iasi (Romania); Mareci, Daniel, E-mail: danmareci@yahoo.com [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, 73 Prof. Dr. Doc. D. Mangeron Street, 700050 Iasi (Romania); Souto, Ricardo Manuel, E-mail: rsouto@ull.es [Department of Chemistry, Universidad de La Laguna, P.O. Box 456, E-38200 La Laguna, Tenerife (Spain); Institute of Material Science and Nanotechnology, Universidad de La Laguna, E-38200 La Laguna, Tenerife (Spain)

2016-11-01

Highlights: • New quarternary Ti-based alloy for biomaterial application. • Combined hydroxyapatite-zirconia coating produced by pulsed laser deposition. • Porous layer formed on the coated alloy blocks electron transfer reactions. • Electrochemical behaviour consistent with passive film with duplex structure. • HA–ZrO{sub 2} coated Ti-21Nb-15Ta-6Zr exhibits high potential for osseointegration. - Abstract: A new titanium base Ti-21Nb-15Ta-6Zr alloy covered with hydroxyapatite-zirconia (HA–ZrO{sub 2}) by pulsed laser deposition (PLD) technique was characterized regarding its corrosion resistance in simulated physiological Ringer’s solution at 37 °C. For the sake of comparison, Ti-6Al-4V standard implant alloy, with and without hydroxyapatite-zirconia coating, was also characterized. Multiscale electrochemical analysis using both conventional averaging electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization, and spatially-resolved microelectrochemical techniques (scanning electrochemical microscopy, SECM) were used to investigate the electrochemical behaviour of the materials. In addition, scanning electron microscopy evidenced that no relevant surface morphology changes occurred on the materials upon immersion in the simulated physiological solution, despite variations in their electrochemical behaviour. Although uncoated metals appear to show better performances during conventional corrosion tests, the response is still quite similar for the HA–ZrO{sub 2} coated materials while providing superior resistance towards electron transfer due to the formation of a more dense film on the surface, thus effectively behaving as a passive material. It is believed corrosion of the HA–ZrO{sub 2} coated Ti-21Nb-15Ta-6Zr alloy will have negligible effect upon biochemical and cellular events at the bone-implant interface and could facilitate osseointegration.

Study of sorption processes of copper on synthetic hydroxyapatite

International Nuclear Information System (INIS)

Rosskopfova, O.; Galambos, M.; Ometakova, J.; Rajec, P.; Caplovicova, M.

2012-01-01

The sorption of copper on synthetic hydroxyapatite was investigated using a batch method and radiotracer technique. The hydroxyapatite sample prepared by a wet precipitation process was of high crystallinity with Ca/P ratio of 1.688. The sorption of copper on hydroxyapatite was pH independent ranging from 4 to 6 as a result of buffering properties of hydroxyapatite. The adsorption of copper was rapid and the percentage of Cu sorption was >98% during the first 15-30 min of the contact time. The experimental data for sorption of copper have been interpreted in the term of Langmuir isotherm. The sorption of Cu 2+ ions was performed by ion-exchange with Ca 2+ cations on the crystal surface of hydroxyapatite under experimental conditions. The competition effect of Zn 2+ , Fe 2+ and Pb 2+ towards Cu 2+ sorption was stronger than that of Co 2+ , Ni 2+ and Ca 2+ ions. The ability of the bivalent cations to depress the sorption of copper on hydroxyapatite was in the following order Pb 2+ > Fe 2+ > Zn 2+ > Co 2+ ∼ Ni 2+ . (author)

The synthesis of hydroxyapatite through the precipitation method.

Science.gov (United States)

Shah, Rizal K; Fahmi, M N; Mat, Akil H; Zainal, Arifin A

2004-05-01

Hydroxyapatite (HA) has been earmarked as suitable for implantation within the human of its chemical makeup to human bone. In this paper, HA powders were synthesized via the precipitation method where phosphoric acid (H3PO4) was titrated into calcium hydroxide solution [Ca(OH)2]. Two parameters such as temperature and stirring rate were identified as factors that influenced the amount and purity of HA powder. Phase identification of the synthesized powder was done using X-Ray Diffraction (XRD). The results show that HA phase can be synthesized from this titration process of Ca(OH)2 and H3PO4 with yield amount of HA powder around 45 - 61 grams but with less than hundred percent purity. In order to study the effect of heat treatment to HA crystals structure, HA powder was calcined at 850 degrees C for 2 hours. It's found that the degree of crystallinity increases after calcination because of lattice expansion when the materials were heated at higher temperature

Impedance and modulus spectroscopic study of nano hydroxyapatite

Science.gov (United States)

Jogiya, B. V.; Jethava, H. O.; Tank, K. P.; Raviya, V. R.; Joshi, M. J.

2016-05-01

Hydroxyapatite (Ca10 (PO4)6 (OH)2, HAP) is the main inorganic component of the hard tissues in bones and also important material for orthopedic and dental implant applications. Nano HAP is of great interest due to its various bio-medical applications. In the present work the nano HAP was synthesized by using surfactant mediated approach. Structure and morphology of the synthesized nano HAP was examined by the Powder XRD and TEM. Impedance study was carried out on pelletized sample in a frequency range of 100Hz to 20MHz at room temperature. The variation of dielectric constant, dielectric loss, and a.c. conductivity with frequency of applied field was studied. The Nyquist plot as well as modulus plot was drawn. The Nyquist plot showed two semicircle arcs, which indicated the presence of grain and grain boundary effect in the sample. The typical behavior of the Nyquist plot was represented by equivalent circuit having two parallel RC combinations in series.

Tumor ocular metastásico Metastatic ocular tumor

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Martha G Domínguez Expósito

2004-06-01

Full Text Available El carcinoma metastásico del ojo es considerado la neoplasia maligna que más frecuente se encuentra de forma intraocular. Solo cerca del 10 % de las personas que tienen una o más lesiones metastásicas intraoculares son detectadas clínicamente antes de la muerte. A menudo, el carcinoma metastásico ocular es diagnosticado por el oftalmólogo ante la presencia de síntomas oculares. Las lesiones están localizadas con preferencia en coroides. Nos motivo a realizar la presentación de este caso la presencia de lesiones intraoculares múltiples tumorales metastásicos en un paciente cuyo síntoma de presentación fue la disminución de la agudeza visualThe eye metastatic carcinoma is considered the most frequently found intraocular malignant neoplasia. Only 10 % of the persons with one or more metastatic intraocular injuries are clinically detected before death. The metastatic ocular carcinoma is often diagnosed by the ophthalmologist in the presence of ocular symptoms. The injuries are preferably located in the choroid. The appearance of multiple metastatic intraaocular tumoral injuries in a patient whose chief complaint was the reduction of visual acuity motivated us to presente this case

Iron(III) and manganese(II) substituted hydroxyapatite nanoparticles: Characterization and cytotoxicity analysis

International Nuclear Information System (INIS)

Li Yan; Nam, C T; Ooi, C P

2009-01-01

Calcium hydroxyapatite (HA) is the main inorganic component of natural bones and can bond to bone directly in vivo. Thus HA is widely used as coating material on bone implants due to its good osteoconductivity and osteoinductivity. Metal ions doped HA have been used as catalyst or absorbents since the ion exchange method has introduced new properties in HA which are inherent to the metal ions. For example, Mn 2+ ions have the potential to increase cell adhesion while Fe 3+ ions have magnetic properties. Here, Fe(III) substituted hydroxyapatite (Fe-HA) and Mn(II) substituted hydroxyapatite (Mn-HA) were produced by wet chemical method coupled with ion exchange mechanism. Compared with pure HA, the colour of both Fe-HA and Mn-HA nanoparticles changed from white to brown and pink respectively. The intensity of the colours increased with increasing substitution concentrations. XRD patterns showed that all samples were single phased HA while the FTIR spectra revealed all samples possessed the characteristic phosphate and hydroxyl adsorption bands of HA. However, undesired adsorption bands of carbonate substitution (B-type carbonated HA) and H 2 O were also detected, which was reasonable since the wet chemical method was used in the synthesis of these nanoparticles. FESEM images showed all samples were elongated spheroids with small size distribution and of around 70 nm, regardless of metal ion substitution concentrations. EDX spectra showed the presence of Fe and Mn and ICP-AES results revealed all metal ion substituted HA were non-stoichiometric (Ca/P atomic ratio deviates from 1.67). Fe-HA nanoparticles were paramagnetic and the magnetic susceptibility increased with the increase of Fe content. Based on the extraction assay for cytotoxicity test, both Fe-HA and Mn-HA displayed non-cytotoxicity to osteoblast.

Effect of Zn{sup 2+}, Fe{sup 3+} and Cr{sup 3+} addition to hydroxyapatite for its application as an active constituent of sunscreens

Energy Technology Data Exchange (ETDEWEB)

De Araujo, T S; De Souza, S O; De Sousa, E M B, E-mail: tatiana.araujo@cefetse.edu.b

2010-11-01

Biocompatible phosphate materials are used in different applications like bone and dental implants, drug delivery systems and others, but could also be applied in inorganic sunscreens. Using sunscreens is extremely necessary, because long time exposure to sun can cause skin cancer. In this work chemical precipitation method has been used to produce hydroxyapatite. Cr{sup 3+}, Zn{sup 2+} and Fe{sup 3+} doped samples were characterized using powder X-Ray Diffraction (XRD) and Optical Absorption techniques. X-ray diffraction measurements confirmed the materials were in the expected crystalline structures. The crystallite size as measured from the X-ray pattern was 23-27 nm ({+-}1). The absorption spectra in the ultraviolet and visible ranges indicate that appropriately doped and sized hydroxyapatite particles may have potential applications as active constituents of sunscreens.

Detection of hydroxyapatite in calcified cardiovascular tissues.

Science.gov (United States)

Lee, Jae Sam; Morrisett, Joel D; Tung, Ching-Hsuan

2012-10-01

The objective of this study is to develop a method for selective detection of the calcific (hydroxyapatite) component in human aortic smooth muscle cells in vitro and in calcified cardiovascular tissues ex vivo. This method uses a novel optical molecular imaging contrast dye, Cy-HABP-19, to target calcified cells and tissues. A peptide that mimics the binding affinity of osteocalcin was used to label hydroxyapatite in vitro and ex vivo. Morphological changes in vascular smooth muscle cells were evaluated at an early stage of the mineralization process induced by extrinsic stimuli, osteogenic factors and a magnetic suspension cell culture. Hydroxyapatite components were detected in monolayers of these cells in the presence of osteogenic factors and a magnetic suspension environment. Atherosclerotic plaque contains multiple components including lipidic, fibrotic, thrombotic, and calcific materials. Using optical imaging and the Cy-HABP-19 molecular imaging probe, we demonstrated that hydroxyapatite components could be selectively distinguished from various calcium salts in human aortic smooth muscle cells in vitro and in calcified cardiovascular tissues, carotid endarterectomy samples and aortic valves, ex vivo. Hydroxyapatite deposits in cardiovascular tissues were selectively detected in the early stage of the calcification process using our Cy-HABP-19 probe. This new probe makes it possible to study the earliest events associated with vascular hydroxyapatite deposition at the cellular and molecular levels. This target-selective molecular imaging probe approach holds high potential for revealing early pathophysiological changes, leading to progression, regression, or stabilization of cardiovascular diseases. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Hydroxyapatite coatings of fracture fixation plates for orthopedic applications

International Nuclear Information System (INIS)

Omar, M.A.; Abdullah, N.S.; Yahya, N.M.; Subuki, I.; Hassan, N.; Mohamad, S.M.

2007-01-01

The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to improve their adhesion to bone. The present study investigates the plasma sprayed process of HA on the fracture fixation plates fabricated by metal injection moulding process. The phase and microstructure of the coatings were studied and their microhardness measured. The phase composition of coatings was analyzed by the use of X-ray diffraction method. The homogeneity of the deposit and coating thickness were evaluated using scanning electron microscope (SEM). The results suggest that the nature of the coating morphology, phase and crystallinity changes with respect to the plasma sprayed processing parameters. The XRD revealed the presence of both amorphous and crystalline phases. In addition, the powder particles also melt partially in some region and coating microstructure varied from a porous structure to a smooth glassy structure or a typical lamellar structure. (author)

Alergia ocular: un reto diagnóstico Ocular allergy: a diagnostic challenge

Directory of Open Access Journals (Sweden)

Ricardo Cardona Villa

2007-12-01

Full Text Available El ojo es uno de los órganos más sensibles y está permanentemente expuesto a diversos agentes ambientales. Dado que la conjuntiva es un tejido inmunológicamente activo, no es sorprendente que sea un sitio común de respuestas alérgicas. Las alergias oculares son un grupo de enfermedades que afectan la superficie conjuntival y están asociadas usualmente a reacciones de hipersensibilidad tipo 1. Pueden ser divididas en varias categorías: conjuntivitis alérgica estacional, conjuntivitis alérgica perenne, queratoconjuntivitis vernal y queratoconjuntivitis atópica. La inflamación de la superficie ocular produce prurito, lagrimeo, edema conjuntival y fotofobia. Como en otras enfermedades alérgicas, se puede desarrollar una condición crónica, acompañada de remodelación de los tejidos oculares. Las estrategias para el tratamiento de la alergia ocular han aumentado exponencialmente y los clínicos disponen de un inventario cada vez mayor de agentes dirigidos a la protección del ojo contra la inflamación. En este trabajo presentamos una revisión sobre las principales formas de alergia ocular, haciendo énfasis en el cuadro clínico, el diagnóstico y las nuevas opciones terapéuticas disponibles en la actualidad. The eye, one of the most sensitive organs, is permanently exposed to different environmental agents. Since the conjunctiva is an immunologically active tissue, it is not surprising for it to be a common site for allergic responses. Ocular allergies constitute a group of diseases affecting the conjunctival surface; they are usually associated with type 1 hypersensitivity reactions. This disorder can be divided into several categories: seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal keratoconjunctivitis and atopic keratoconjunctivitis. Ocular surface inflammation results in itching, tearing, conjunctival edema, and photophobia. As is the case with other allergic diseases, a chronic situation can also

Characterization of hydroxyapatite substituted with silicon

International Nuclear Information System (INIS)

Silva, H.M. da; Soares, G.A.; Mateescu, M.; Anselme, K.; Palard, M.; Champion, E.

2009-01-01

Incorporation of silicon (Si) ions into hydroxyapatite structure (HA) influences on physical, chemical and physiological properties. Some studies reported the improved bioactivity Si substitution, and it also accelerates the biomineralization process. The main objective of this work is to characterize stoichiometric hydroxyapatite and hydroxyapatite substituted with 1.13% in weight of Si (SiHA) using a wet precipitation method followed by a heat treatment. SEM/EDS, AFM, DRX and FTIR analyses were used to characterize the samples. EDS and FTIR results confirmed the presence of Si. Silicon induces small changes on crystal structure of HA, not detected on X-ray diffraction patterns of sintered tablets of SiHA and HA. No secondary phases were observed, that indicates the Si had entered the HA lattice. (author)

Si-substituted hydroxyapatite nanopowders: Synthesis, thermal stability and sinterability

International Nuclear Information System (INIS)

Bianco, Alessandra; Cacciotti, Ilaria; Lombardi, Mariangela; Montanaro, Laura

2009-01-01

Synthetic hydroxyapatites incorporating small amounts of Si have shown improved biological performances in terms of enhanced bone apposition, bone in-growth and cell-mediated degradation. This paper reports a systematic investigation on Si-substituted hydroxyapatite (Si 1.40 wt%) nanopowders produced following two different conventional wet methodologies: (a) precipitation of Ca(NO 3 ) 2 .4H 2 O and (b) titration of Ca(OH) 2 . The influence of the synthesis process on composition, thermal behaviour and sinterability of the resulting nanopowders is studied. Samples were characterised by electron microscopy, induced coupled plasma atomic emission spectroscopy, thermal analysis, infrared spectroscopy, N 2 adsorption measurements, X-ray diffraction and dilatometry. Semicrystalline Si-substituted hydroxyapatite powders made up of needle-like nanoparticles were obtained, the specific surface area ranged between 84 and 110 m 2 /g. Pure and Si-substituted hydroxyapatite nanopowders derived from Ca(NO 3 ) 2 .4H 2 O decomposed around 1000 deg. C. Si-substituted hydroxyapatite nanopowders obtained from Ca(OH) 2 were thermally stable up to 1200 deg. C and showed a distinct decreased thermal stability with respect to the homologous pure sample. Si-substituted hydroxyapatites exhibited higher sintering temperature and increased total shrinkage with respect to pure powders. Nanostructured dense ceramics were obtained by sintering at 1100 deg. C Si-substituted hydroxyapatites derived from Ca(OH) 2

A process for the development of strontium hydroxyapatite

International Nuclear Information System (INIS)

Zahra, N; Fayyaz, M; Iqbal, W; Irfan, M; Alam, S

2014-01-01

A procedure for the preparation of Strontium Hydroxyapatite is adapted to produce high purity and better homogeneity ceramic with good Crystallinity. The strontium substituted bone cement has potential for use in orthopedic surgeries. Ionic Strontium (Sr) in humans shares the same physiological pathway as calcium and can be deposited in the mineral structure of the bone. In the present study, a novel concept of preparing Sr-contained Hydroxyapatite bone cement by using a precipitation method is proposed to get an ideal biomaterial that possesses potential degradability and more excellent pharmacological effect. Chemical analysis, Fourier Transform Infra Red analysis and Thermogravimetric/ Differential Scanning Calorimetric studies were conducted on prepared Strontium Hydroxyapatite sample to characterize the incorporation of 15% Sr 2 + into the crystal lattice of Hydroxyapatite. Strontium was quantitatively incorporated into Hydroxyapatite where its substitution for calcium provoked a linear shift of the infrared absorption bands of the hydroxyl and phosphate groups. Thus, the formation of Sr-HAp was confirmed by Chemical Analysis, FT-IR and TGA/DSC results

A process for the development of strontium hydroxyapatite

Science.gov (United States)

Zahra, N.; Fayyaz, M.; Iqbal, W.; Irfan, M.; Alam, S.

2014-06-01

A procedure for the preparation of Strontium Hydroxyapatite is adapted to produce high purity and better homogeneity ceramic with good Crystallinity. The strontium substituted bone cement has potential for use in orthopedic surgeries. Ionic Strontium (Sr) in humans shares the same physiological pathway as calcium and can be deposited in the mineral structure of the bone. In the present study, a novel concept of preparing Sr-contained Hydroxyapatite bone cement by using a precipitation method is proposed to get an ideal biomaterial that possesses potential degradability and more excellent pharmacological effect. Chemical analysis, Fourier Transform Infra Red analysis and Thermogravimetric/ Differential Scanning Calorimetric studies were conducted on prepared Strontium Hydroxyapatite sample to characterize the incorporation of 15% Sr2+ into the crystal lattice of Hydroxyapatite. Strontium was quantitatively incorporated into Hydroxyapatite where its substitution for calcium provoked a linear shift of the infrared absorption bands of the hydroxyl and phosphate groups. Thus, the formation of Sr-HAp was confirmed by Chemical Analysis, FT-IR and TGA/DSC results.

A process for the development of strontium hydroxyapatite

International Nuclear Information System (INIS)

Zahra, N.; Fayyaz, M.; Iqbal, W.; Irfan, M.; Alam, S.

2013-01-01

A procedure for the preparation of Strontium Hydroxyapatite is adapted to produce high purity and better homogeneity ceramic with good Crystallinity. The strontium substituted bone cement has potential for use in orthopedic surgeries. Ionic Strontium (Sr) in humans shares the same physiological pathway as calcium and can be deposited in the mineral structure of the bone. In the present study, a novel concept of preparing Sr-contained Hydroxyapatite bone cement by using a precipitation method is proposed to get an ideal biomaterial that possesses potential degradability and more excellent pharmacological effect. Chemical analysis, Fourier Transform Infra Red analysis and Thermogravimetric/ Differential Scanning Calorimetric studies were conducted on prepared Strontium Hydroxyapatite sample to characterize the incorporation of 15 percentage Sr2+ into the crystal lattice of Hydroxyapatite. Strontium was quantitatively incorporated into Hydroxyapatite where its substitution for calcium provoked a linear shift of the infrared absorption bands of the hydroxyl and phosphate groups. Thus, the formation of Sr-HAp was confirmed by Chemical Analysis, FT-IR and TGA/DSC results. (author)

In vitro corrosion and cytocompatibility properties of nano-whisker hydroxyapatite coating on magnesium alloy for bone tissue engineering applications.

Science.gov (United States)

Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

2015-03-17

We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.

X-ray and neutron diffraction studies of crystallinity in hydroxyapatite coatings.

Science.gov (United States)

Girardin, E; Millet, P; Lodini, A

2000-02-01

To standardize industrial implant production and make comparisons between different experimental results, we have to be able to quantify the crystallinity of hydroxyapatite. Methods of measuring crystallinity ratio were developed for various HA samples before and after plasma spraying. The first series of methods uses X-ray diffraction. The advantage of these methods is that X-ray diffraction equipment is used widely in science and industry. In the second series, a neutron diffraction method is developed and the results recorded are similar to those obtained by the modified X-ray diffraction methods. The advantage of neutron diffraction is the ability to obtain measurements deep inside a component. It is a nondestructive method, owing to the very low absorption of neutrons in most materials. Copyright 2000 John Wiley & Sons, Inc.

Hydroxyapatite nanorods: soft-template synthesis, characterization and preliminary in vitro tests.

Science.gov (United States)

Nguyen, Nga Kim; Leoni, Matteo; Maniglio, Devid; Migliaresi, Claudio

2013-07-01

Synthetic hydroxyapatite nanorods are excellent candidates for bone tissue engineering applications. In this study, hydroxyapatite nanorods resembling bone minerals were produced by using soft-template method with cetyltrimethylammonium bromide. Composite hydroxyapatite/poly(D, L)lactic acid films were prepared to evaluate the prepared hydroxyapatite nanorods in terms of cell affinity. Preliminary in vitro experiments showed that aspect ratio and film surface roughness play a vital role in controlling adhesion and proliferation of human osteoblast cell line MG 63. The hydroxyapatite nanorods with aspect ratios in the range of 5.94-7 were found to possess distinctive properties, with the corresponding hydroxyapatite/poly(D, L)lactic acid films promoting cellular confluence and a fast formation of collagen fibers as early as after 7 days of culture.

Preparing hydroxyapatite-silicon composite suspensions with homogeneous distribution of multi-walled carbon nano-tubes for electrophoretic coating of NiTi bone implant and their effect on the surface morphology

International Nuclear Information System (INIS)

Khalili, Vida; Khalil-Allafi, Jafar; Xia, Wei; Parsa, Alireza B.; Frenzel, Jan; Somsen, Christoph; Eggeler, Gunther

2016-01-01

Graphical abstract: - Highlights: • The stable composite suspensions of hydroxyapatite, silicon and multi-walled carbon nano-tubes was prepared using functionalization of and multi-walled carbon nano-tubes in HNO_3 vapor and triethanolamine as dispersing agent. • The zeta potential of composite suspensions is less than that of hydroxyapatite suspension. • The silicon particles presence in suspension causes to decrease the charge carrier in suspension and current density during electrophoretic deposition. • The orientation of multi-walled carbon nano-tubes to parallel direction of the applied electric field during electrophoretic deposition can facilitate their moving towards the cathode and increase current density. • The more zeta potential of suspension, the lower roughness of coatings during electrophoretic deposition. - Abstract: Preparing a stable suspension is a main step towards the electrophoretically depositing of homogeneous and dense composite coatings on NiTi for its biomedical application. In the present study, different composite suspensions of hydroxyapatite, silicon and multi-walled carbon nano-tubes were prepared using n-butanol and triethanolamine as media and dispersing agent, respectively. Multi-walled carbon nanotubes were first functionalized in the nitric acid vapor for 15 h at 175 °C, and then mixed into suspensions. Thermal desorption spectroscopy profiles indicate the formation of functional groups on multi-walled carbon nano-tubes. An excellent suspension stability can be achieved for different amounts of triethanolamine. The amount of triethanolamine can be increased by adding a second component to a stable hydroxyapatite suspension due to an electrostatic interaction between components in suspension. The stability of composite suspension is less than that of the hydroxyapatite suspension, due to density differences, which under the gravitational force promote the demixing. The scanning electron microscopy images of the

Incidência de opacificação de cápsula posterior em pacientes submetidos à facoemulsificação e implante de lentes intra-oculares acrílicas hidrofílicas expansíveis Incidence of posterior capsule opacification in patients submitted to phacoemulsification and expandable acrylic intraocular lens implantation

Directory of Open Access Journals (Sweden)

Hilton Arcoverde Gonçalves de Medeiros

2006-06-01

Full Text Available OBJETIVO: Avaliar prospectivamente os resultados das lentes intra-oculares de polímeros expansíveis implantadas em pacientes submetidos à facoemulsificação, quanto à incidência de opacificação de cápsula posterior, levando em consideração a biocompatibilidade das lentes expansíveis. MÉTODOS: O grupo de estudo foi composto por 830 pacientes, 1.200 olhos, que foram submetidos a facoemulsificação, utilizando a mesma técnica, variando-se apenas o diâmetro da capsulorrexe, pelo mesmo cirurgião, no período de 1998 a 2002, com implante de lente intra-ocular hidrofílica expansível. O acompanhamento médio foi de 2,4 anos, variando de seis meses a quatro anos. RESULTADOS: O número total de opacificação de cápsula posterior foi de 54 casos. CONCLUSÃO: A incidência de opacificação de cápsula posterior encontrada no grupo foi de 4,6%.PURPOSE: To evaluate prospectively the results of expandable acrylic intraocular lenses in patients submitted to phacoemulsification as regard posterior capsule opacification. METHODS: The study group consisted of 830 patients, 1,200 eyes that underwent phacoemulsification from 1998 to 2002, by the same surgeon, using the same technique but with different diameters of capsulorrhexis, with expandable hydrophilic acrylic intraocular lens implantation. The mean follow-up was 2.4 years, ranging from 6 months to 4 years. RESULTS: The total number of posterior capsule opacification was 54 cases. CONCLUSIONS: The incidence of posterior capsule opacification was 4.6% in these patients.