Hydroxyapatite‐Coated Ti6Al4V With Liposome‐Encapsulated Gooseberry Extract for Orthopedic Applications

ABSTRACT

This study investigates gooseberry ( Phyllanthus emblica ) extract (GB) as a bioactive additive to provide antibacterial activity and activity against osteosarcoma cells in hydroxyapatite‐coated Ti6Al4V implants while maintaining osteoblast cytocompatibility. Aqueous extraction of GB yields a multicomponent formulation containing hydrophilic bioactive constituents that are prone to rapid release and poor retention under physiological conditions, thereby limiting their utility in implant‐based delivery systems. To address this limitation, GB was encapsulated within liposomes to mitigate burst release and enable sustained delivery from implant surfaces. When incorporated onto plasma‐sprayed hydroxyapatite‐coated Ti6Al4V substrates, liposomal encapsulation reduced burst release within the first 48 h by 18% at pH 5.0 and 27% at pH 7.4. The formulation reduced osteosarcoma cell viability by 58% ± 7% after 11 days and decreased Pseudomonas aeruginosa and Staphylococcus aureus viability by 78% ± 3% and 45% ± 6%, respectively, within 48 h. Importantly, the system exhibited no cytotoxic effects toward osteoblasts, as demonstrated by MTT cell viability assays. In vivo evaluation of GB‐treated implants after 6 weeks further demonstrated no adverse effect on early bone formation, with histological analysis showing a trend toward increased bone formation relative to control implants. These results demonstrate the feasibility of stabilizing and delivering a complex, hydrophilic natural extract from implant surfaces using liposomal encapsulation while maintaining osteoblast compatibility and without adversely affecting early bone formation in vivo.