EFFECT OF TEMPERATURE AND ULTRAVIOLET LIGHT ON THE BACTERIAL KILL EFFECTIVENESS OF ANTIBIOTIC-INFUSED 3D PRINTED IMPLANTS
The cost associated with the treatment of Prosthetic Joint Infections ( PJI ) is over a billion dollars , in the United States alone . The current gold standard for treatment of infection after total knee arthroplasty is a 2-stage process whereby the implant is removed and a temporary spacer made of PMMA ( bone cement ) with antibiotics is inserted . The patient receives a 6-8 week course of intravenous antibiotics , and then returns to surgery for a re-implantation of a new joint replacement . Unfortunately , PMMA as a drug delivery material has limitations in terms of mechanical and drug-eluting properties . Furthermore , the polymerization reaction for PMMA is highly exothermic , thereby limiting the variety of antibiotics used for the treatment of infections . We have designed a family of 3D printed orthopaedic implants that not only overcome the limitations of PMMA , but can also be designed to be load bearing and customized to individual patient needs . Our implants are `smart ’ since they incorporate built-in design features such as micro-channels and reservoirs that enable them to act as antibiotic delivery vehicles . From the perspective of fundamental science , such implants must necessarily comply with the competing requirements stemming from both mechanics and biological perspectives . In particular , we examined the effect of print manufacturing conditions ( high temperature and UV light exposure ) on the kill effectiveness of eluted antibiotics in collaboration with Cooper University Health Care . Our results indicate that 3D print manufacturing conditions such as those encountered in FDM and SLA printing do not adversely impact the bacterial kill effectiveness of the printed implants .
Shivakumar Ranganathan Associate Professor
VIRGINIA TECH MECHANICAL ENGINEERING ANNUAL REPORT • 2019-2020 • RESEARCH 37