Synthesis and characterization of silica-chitosan hybrid materials as antibacterial coatings for titanium implants

Abstract

Although implants are becoming increasingly common in dental practice, before implantation strict patient selection criteria have to be implemented since the implants should have a good chance of osseointegration into the maxillary bone. Moreover, the implanted sites can become severely infected and, consequently, the implant might have to be removed. To avoid implant-related infections and to promote the osseointegration of commercial Titanium implants, different silica-chitosan matrices were synthesized using the sol-gel process. Three different alkoxysilanes were used, methyltrimethoxysilane (MTMOS), 3glycidoxypropyltrimethoxysilane (GPTMS), and tetraethoxysilane (TEOS). The network formed during the matrix synthesis gradually degrades in aqueous media, and during this hydrolytic degradation, silicon is released, inducing bone formation. Chitosan, with its high biocompatibility and strong antibacterial activity, was selected to confer antibacterial properties to the coatings. The synthesized hybrids were characterized using 29 Si-and 13 C-NMR to verify the correct formation of the network. The technique was also used to confirm the covalent union between chitosan and the silicon network. Hydrolytic degradation and silicon release studies in the aqueous media were examined, showing the effective silicon release from the hybrids. The analysis of cell cultures in vitro demonstrated that the hybrid coatings were not cytotoxic and promoted cell proliferation on their surfaces. The coatings containing 5%-10% chitosan had substantial antibacterial properties. The introduction of different amounts of chitosan and TEOS modulated the degradation of the coatings and, consequently, the Si release.

Silver Nanoparticles on Chitosan/Silica Nanofibers: Characterization and Antibacterial Activity

“…According to the literature reports, a silica phase can be incorporated into the chitosan matrix to improve the mechanical properties of a biopolymer [33]. The creation of inorganic/biopolymer composites as chitosan/silica hybrids with advanced physicochemical properties determines the extent of the improvement of biopolymer stability by the bioinert component.…”

Surface Characterization of Electro-Assisted Titanium Implants: A Multi-Technique Approach

“…As far as coating synthesis is concerned, ATR-FTIR spectroscopy is widely used to confirm coating formation on titanium [51][52][53][54][55][56][57][58]. For example, the hydroxyapatite/lignin composite coatings on titanium implants, developed by Erakovic et al, were also studied by means of ATR-FTIR.…”

Bibliographic review on the state of the art of strontium and zinc based regenerative therapies. Recent developments and clinical applications

“…76 Different surface modifications have been recently described for inclusion of osteogenic elements. 77 On this subject, eight articles discussed the possibilities of doping titanium surfaces with Sr, well known for its possibilities to intensify bone regenerating features, such as SrTiO 3 /TiO 2 76 and Sr loaded titania nanotubes, 78 consisting of adding the Sr through a hydrothermal treatment. 79,80 In both cases, the RAW 264.7 cell line was used for the experiment in vitro, although B. Mi et al expanded their experiment in vivo, performing it on Sprague-Dawley rats (Fig.…”