The use of polymer/antibiotic film and bio-activated ceramic to regulate the antimicrobial and bone growth effects on porous titanium beads implant

Abstract

Total hip arthroplasty (THA) is an established procedure to restore mobility and to improve quality of life in patients that suffer from severe osteoarthritis or femoral fractures in close proximity to the hip joint The technology of sintering coated titanium (Ti) bead on titanium prosthesis has been developed for many years The porous surface of the sintered titanium beads has good roughness and porosity to induce better bone ingrowth After implantation the formation of a bacterial surface biofilm and compromised immunity at the implant/tissue interface may lead to persistent infections around titanium implants So far extensive inflammation and poor osseointegration have been identified as the major reasons for early orthopedic implant failures In this study we focus on the development of a polymer-coated ceramic composite for antimicrobial drug delivery A micro-arc oxidation (MAO) was used to produce a porous structure comprising calcium acetate hydrate (Ca(CH3COO)2‧H2O) and sodium phosphate monobasic monohydrate (NaH2PO4‧H2O) for improving the biocompatibility of titanium Using a drop-dry method aqueous drug was loaded into the porous surface Finally Polylactic acid-polyglycolic acid (PLGA) a biodegradable polymer and Poly gamma glutamic acid (?-PGA) were coated through spin coating as a barrier to control drug release The use of PLGA film can effectively regulate the release rate and amount of the antibiotic dose within the body The phenomenon of inflammation or infection decreased for the effect of long-circulated drug release The bactericidal effect of antibiotic on the porous surface was evaluated by using MRSA bacteria (SA10780) Additionally the results obtained from UV-Vis analysis suggested that the drug was successfully filled into coatings and released over time with antibiotic/Polymer solution which could provide a high bactericidal effect against MRSA by the bactericidal effect of antibiotic These findings demonstrate that using porous structure with PLGA and ?-PGA is promising as cost-effective drug delivery formulation for delivering drugs locally and continuously Furthermore antimicrobial study demonstrates that the antimicrobial activity of antibiotic toward the growth inhibition of a bacterium model of MRSA is not compromised after being loaded into the porous structure We demonstrate the preparation and characteristics of Ti implants with a layer of MAO porous coating that have extended drug release properties biocompatibility for human osteoblasts and potentially improved antibacterial properties With the reserved drug activity the porous structure based drug delivery system may find various applications in tissue engineering and pharmaceutical science

Date of Award	2016 Aug 31
Original language	English
Supervisor	Tzer-Min Lee (Supervisor)