JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE RESEARCH ARTICLE J Tissue Eng Regen Med 2009; 3: 501–511. Published online 20 July 2009 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/term.186 Bone healing performance of electrophoretically deposited apatite – wollastonite/chitosan coating on titanium implants in rabbit tibiae Smriti Sharma 1 , Dronacharya J. Patil 3 , Vivek P. Soni 1 , L. B. Sarkate 3 , Gajendra S. Khandekar 3 and Jayesh R. Bellare 1,2 * 1 School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India 2 Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India 3 Department of Veterinary Surgery and Radiology, Bombay Veterinary College, Parel, Mumbai, India 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. Copyright  2009 John Wiley & Sons, Ltd. Received 31 December 2008; Revised 8 April 2009; Accepted 12 May 2009 Keywords orthopaedic implants; apatite–wollastonite/chitosan coating; electrophoretic deposition; radiography; scintigraphy; histopathology; fluorescence labelling; bone bonding 1. Introduction There is an increasing group of patients with challenging bone problems where implants are more prone to failure, which is caused mainly due to implant loosening and peri-implantitis. This can ultimately lead to inflammation in the bone surrounding the implant and bone loss (recession). There is a need for simple methods that *Correspondence to: Jayesh R. Bellare, School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India. E-mail: jb@iitb.ac.in improve short- and long-term implant stability. An increase in the number of orthopaedic and dental prosthetic surgery motivated researchers to explore for new biomaterials for bone implants (Sollazzo et al., 2008). The clinical success of the implants is related to their early osseo-integration (Guehennec et al., 2007). The rate and quality of osseo-integration in titanium implants are related to their surface properties. New techniques of surface treatment and deposition have been developed to modify the implant surface and thus give to it new properties, such as protection of the implant from degradation and corrosion, to improve tissue integration. Copyright  2009 John Wiley & Sons, Ltd.