Polyurethane-based bioadhesive was synthesized with polyols derived from castor oil (chemically modified and unmodified) and hexamethylene diisocyanate with chitosan addition as a bioactive filler. The objective was to evaluate the effect of type of polyols with the incorporation of low-concentrations of chitosan on the mechanical and biological properties of the polymer to obtain suitable materials in the design of biomaterials. The results showed that increasing physical crosslinking increased the mechanical and adhesive properties. An in vitro cytotoxic test of polyurethanes showed cellular viability. The biocompatibility of the polyurethanes favors the adhesion of L929 cells at 6, 24, and 48 h. The polyurethanes showed bacterial inhibition depending on the polyol and percentage of chitosan. The antibacterial effect of the polyurethanes for Escherichia coli decreased 60–90% after 24 h. The mechanical and adhesive properties together with biological response in this research suggested these polyurethanes as external application tissue bioadhesives.

A novel multifunctional and biocompatible ultrananocrystalline diamond (UNCD) film technology developed recently represents a new material with a unique combination of functionalities, including biocompatibility, to enable a new generation of implantable medical devices and scaffolds for tissue engineering. Following a description of the synthesis and properties of UNCD films and a comparison with other diamond film technologies, this article focuses on descriptions of key UNCD-based medical devices to treat specific medical conditions requiring effective therapies: (1) A UNCD-coated microchip (artificial retina) implantable inside the eye on the retina to restore partial vision to people blinded by retinitis pigmentosa and macular degeneration produced by genetically induced degeneration of the retina photoreceptors. (2) A UNCD-coated intraocular device for treatment of glaucoma in the eye. (3) UNCD-coated metal dental implants with potential order of magnitude longer life and superior performance than current implants.