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North Kingstown, RI, United States

Jarrell J.D.,Brown University | Jarrell J.D.,BioIntraface Inc. | Dolly B.,Brown University | Morgan J.R.,Brown University
Journal of Biomedical Materials Research - Part A

Metal-organic chemistry allows for molecular mixing and creation of a range of submicron phase-separated structures from normally brittle metal oxides and flexible polymers with improved bioactivity and delivery properties. In this study, we used a high throughput platform to investigate the in.uence of organic metal oxide doping of polydimethylsiloxane (PDMS) coatings on cellular bioactivity and controlled release of vanadium compared with titanium oxide coatings without additional PDMS. Metal-organic-derived titanium and or vanadium was doped into PDMS and used to form a coating on the bottom of cell culture microplates in the absence of added water, acids, or bases. These hybrid coatings were rapidly screened to establish how titanium and vanadium concentration in.uences cell proliferation, adhesion, and morphology. We demonstrate that titanium doping of PDMS can be used to improve cell proliferation and adhesion, and that vanadium doping caused a biphasic dose response in proliferation. A 28-day vanadium and titanium elution study indicated that titanium was not released, but the presence of PDMS in coatings increased delivery rates of vanadium compared with titania coatings without polymer. Hybrid coatings of titanium-doped polymers have potential for improving wound healing dynamics, soft-tissue integration of medical implants, and use as controlled delivery vehicles. © 2009 Wiley Periodicals, Inc. Source

Tran N.,Brown University | Tran N.,Weiss Center for Orthopaedic Trauma Research | Tran P.A.,Brown University | Tran P.A.,Weiss Center for Orthopaedic Trauma Research | And 10 more authors.
BioMed Research International

Bone infection remains a formidable challenge to the medical field. The goal of the current study is to evaluate antibacterial coatings in vitro and to develop a large animal model to assess coated bone implants. A novel coating consisting of titanium oxide and siloxane polymer doped with silver was created by metal-organic methods. The coating was tested in vitro using rapid screening techniques to determine compositions which inhibited Staphylococcus aureus growth, while not affecting osteoblast viability. The coating was then applied to intramedullary nails and evaluated in vivo in a caprine model. In this pilot study, a fracture was created in the tibia of the goat, and Staphylococcus aureus was inoculated directly into the bone canal. The fractures were fixed by either coated (treated) or non-coated intramedullary nails (control) for 5 weeks. Clinical observations as well as microbiology, mechanical, radiology, and histology testing were used to compare the animals. The treated goat was able to walk using all four limbs after 5 weeks, while the control was unwilling to bear weight on the fixed leg. These results suggest the antimicrobial potential of the hybrid coating and the feasibility of the goat model for antimicrobial coated intramedullary implant evaluation. © 2013 Nhiem Tran et al. Source

Tran N.,Brown University | Tran N.,Weiss Center for Orthopaedic Trauma Research | Kelley M.N.,Brown University | Kelley M.N.,Weiss Center for Orthopaedic Trauma Research | And 11 more authors.
Materials Science and Engineering C

Bacterial infection remains one of the most serious issues affecting the successful installation and retention of orthopedic implants. Many bacteria develop resistance to current antibiotics,which complicates or prevents traditional antibiotic-dependent eradication therapy. In this study, a hybrid coating of titanium dioxide and polydimethylsiloxane (PDMS) was synthesized to regulate the release of silver. The coatings were benefited from the antimicrobial activity of silver ion, the biocompatibility of titanium dioxide, and the flexibility of the polymer. Three studied silver doped coatings with different titanium dioxide-PDMS ratios effectively inhibited the attachment and growth of Staphylococcus aureus and Staphylococcus epidermidis in a dose-dependent manner. The coatings were successfully applied on the discs of polyether ether ketone (PEEK), a common spinal implant material and antibacterial property of these coatingswas assessed via Kirby Bauer assay.More importantly, these selected coatings completely inhibited biofilm formation. The release study demonstrated that the release rate of silver from the coating depended on doping levels and also the ratios of titanium dioxide and PDMS. This result is crucial for designing coatings with desired silver release rate on PEEK materials for antimicrobial applications. © 2014 Elsevier B.V. All rights reserved. Source

Thomas N.P.,Brown University | Tran N.,Brown University | Tran N.,Weiss Center for Orthopaedic Trauma Research | Tran P.A.,Brown University | And 9 more authors.
Journal of Materials Science: Materials in Medicine

Zirconia is a transition metal oxide with current applications to orthopedic implants. It has been shown to up-regulate specific genes involved in bio-integration and injury repair. This study examines the effects of zirconia and polydimethylsiloxane (PDMS) hybrids on the proliferation and viability of human primary osteoblast and fibroblast cells. In this study, zirconia-PDMS hybrid coatings were synthesized using a modified sol gel process. The hybrid material was characterized using optical microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and contact angle analysis. This study demonstrates that Zr-PMDS surface materials display hydrophobic surface properties coupled with a preferential deposition of polymer near the surface. Primary osteoblast and fibroblast proliferation and viability on hybrid coated surfaces were evaluated via a rapid screening methodology using WST-1 and calcein AM assays. The cells were seed at 5,000 cells per well in 96-well plates coated with various composition of Zr-PDMS hybrids. The results showed increasing cell proliferation with increasing zirconia concentration, which peaked at 90 % v/v zirconia. Proliferation of osteoblasts and fibroblasts displayed similar trends on the hybrid material, although osteoblasts displayed a bi-phasic dose response by the calcein AM assay. The results of this current study show that Zr-PDMS may be used to influence tissue-implant integration, supporting the use of the hybrid as a promising coating for orthopedic trauma implants. © 2013 Springer Science+Business Media New York. Source

BioIntraface Inc. | Date: 2009-01-26

Coatings sold as an integral component of implantable medical devices; coatings sold as an integral component of medical devices, namely, surgical instruments, catheters, and surgical support debridement platform; bioactive or photoactive surface coatings sold as an integral component of medical devices, namely, surgical instruments, catheters, and surgical support debridement platform; coatings sold as an integral component of orthopedic fixation devices used in transplant and/or implant surgery; coatings sold as an integral component of medical devices, namely, spinal fusion devices, orthopedic devices for diagnostic and therapeutic use, fracture fixation devices, bone-anchored prosthetics for limb replacement, transcutaneous osseointegrative devices, external fixation pins, devices used in orthopedic surgery to position surgical instruments, implants, and/or patients limbs, medical apparatus and instruments for use in orthopedic or spinal surgery, orthopedic apparatus and instruments, splints (orthopedic or surgical), and vertebral orthopedic devices; anti-bacterial and bioactive coatings sold as an integral component of internal fracture fixation devices; coatings including a polymer or metal oxide sold as an integral component of non-implantable medical devices.

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