Bone healing performance of electrophoretically deposited apatite–wollastonite/chitosan coating on titanium implants in rabbit tibiae

Abstract

Bone healing of tibial defect in rabbit model was used to evaluate a composite coating of apatite-wollastonite/chitosan on titanium implant. This coating has been developed to overcome the shortcomings, such as implant loosening and lack of adherence, of uncoated titanium implant. An electrophoretic deposition technique was used to coat apatite-wollastonite/chitosan on titanium implants. The present study was designed to evaluate the bone response of coated as compared to uncoated titanium implants in an animal model. After an implantation period of 14 (group A), 21 (group B), 35 (group C) and 42 days (group D), the bone-implant interfaces and defect site healing was evaluated using radiography, scintigraphy, histopathology, fluorescence labeling and haematology. Radiography of defect sites treated with coated implants suggested expedited healing. Scintigraphy of coated implant sites indicated faster bone metabolism than uncoated implant sites. Histopathological examination and fluorescence labeling of bone from coated implant sites revealed higher osteoblastic activity and faster mineralization. Faster bone healing in the case of coated implant sites is attributed to higher cell adhesion on electrostatically charged chitosan surfaces and apatite-wollastonite-assisted mineralization at bone-implant interfaces. Haematological studies showed no significant differences in haemoglobin, total erythrocyte and leukocyte counts, done using one way-ANOVA, during the entire study period. Our results show that AW/chitosan-coated implants have the advantages of faster bone healing, increased mechanical strength and good bone-implant bonding.

Nanocoating of Titanium Implant Surfaces with Organic Molecules. Polysaccharides Including Glycosaminoglycans

“…36 The polysaccharides were coated on titanium directly or in cooperation with other molecules such as collagen I, 13 18-21 29 collagen II, 16 calcium phosphate, 32 gelatine 34 and silk fibroin 35 (Tables II and III).…”

“…The animal polysaccharides used for surface modifications were chitosan, which was investigated by in vitro studies, [30][31][32][33][34][35] and in vivo studies. 36 The polysaccharides were coated on titanium directly or in cooperation with other molecules such as collagen I, 13 18-21 29 collagen II, 16 calcium phosphate, 32 gelatine 34 and silk fibroin 35 (Tables II and III).…”

“…35 This might indicate a faster bone matrix mineralisation. 46 The positive effect of chitosan on attachment, proliferation and mineralization of bone cells encouraged to continue investigations on chitosan nanocoating in vivo to confirm the in vitro results.…”

Electrophoretic deposition of biomaterials

“…Bioactivity studies showed that CHIT enhanced the apatite formation rate in SBF, and apatite particles formed in SBF showed sheet-like morphology. It was also shown that AW/CHIT coatings exhibited good adhesion to Ti substrates and haemocompatibility (Sharma et al 2009a,b), as well as faster bone healing when implanted in rabbit tibiae (Sharma et al 2009c). …”

Scaffolds containing chitosan/carboxymethyl cellulose/mesoporous wollastonite for bone tissue engineering

“…CS/CMC scaffolds containing bioactive glass have also been reported for bone tissue engineering applications [17]. Wollastonite (WS) or calcium silicate is a silicon based ceramic particle and is biocompatible, biodegradable and bioactive in nature [18][19][20]. Mesoporous particles are found to possess high specific surface area and pore volume which significantly improved the kinetic process of apatite formation on their surface thereby exhibiting better bioactivity [21,22] Biomaterial interaction with cell could activate intracellular signaling components/regulators resulting in osteogenesis.…”