Friday, September 28, 2018 10:30 AM–12:00 PM abstracts: innovation, surface technology and biomechanics

BACKGROUND CONTEXT Spine implant infections are devastating conditions that incur significant cost and morbidity. Definitive explantation of the implants is often a last resort as it can destabilize the spine. Antibiotic eluting implant coatings have been developed to improve resistance to biofilm infections, although current coatings require a fabrication process that can take several weeks. As such, utilizing branched poly (ethyelene glycol) and poly (allyl mercaptan) (PEG-PAM) polymers, a rapid, point-of-application coating that can be applied in the OR immediately prior to implantation was developed. PURPOSE This study aims to elucidate the role of the rapid application, novel PEG-PAM polymer coating loaded with antibiotics in the prevention of spinal implant biofilm infections. STUDY DESIGN/SETTING This is a basic science investigation utilizing spinal implants coated with PEG-PAM polymer loaded with antibiotics within a mouse model of spine infection. The spine implants are inoculated with bioluminescentStaphylococcus aureusfor longitudinal quantification of bacterial burden. PATIENT SAMPLE Twenty 12-week-oldC57BL/6 wild type mice were utilized, 10 for each experimental group. OUTCOME MEASURES Utilizing an established mouse model of spinal implant infection,in vivobioluminescence imaging was performed using an IVIS Lumina II (PerkinElmer, Hopkinton, MA)on POD 0, 1, 3, 5, 7, 10, 14, 18, 21, and 25 to quantify bacterial burden over time. METHODS A novel, biodegradable coating using branched poly (ethyelene glycol) and poly (allyl mercaptan) (PEG-PAM) polymers was designed to deliver antibiotics. The in vivo efficacy of PEG-PAM coating delivering Vancomycin was tested using a well-established mouse model of spinal implant infection in which bioluminescent Xen 36Staphylococcus aureuswere inoculated on implants surgically inserted into the L4 spinous process. PEG-PAM coating alone and PEG-PAM coating with Vancomycin were tested. The primary outcome was the quantity of bioluminescence produced by bacteria for 24 days following inoculation. RESULTS Bioluminescence levels were elevated with the PEG-PAM coating alone with its curve matching historical infected controls. Initial experiments with one layer of PEG-PAM loaded vancomycin revealed no difference in bioluminescence compared to PEG-PAM coating alone. Subsequent experiments with three layers of PEG-PAM loaded with vancomycin revealed complete suppression of infection at all times points (p CONCLUSIONS Based on these data, triple layered PEG-PAM polymer loaded with Vancomycin provides sustained suppression of bacterial infection. The application process of PEG-PAM polymer was completed within minutes obviating the need for prefabrication and potentially maximizing surgeon flexibility within the OR to add various adjuncts as needed.