Sustained Antibiotic Release from Photopatterned Polymeric Hydrogels and Nanoparticle/Hydrogel Hybrid Systems

Hydrogels have emerged as a multipurpose platform for a myriad of different functions within the biomedical field. Beyond being a tunable and diverse material, hydrogel application in drug delivery is particularly fitting due to the fact that they are biocompatible and can be made biodegradable. Utilizing hydrogels as an antibiotic coating around orthopedic implants will treat numerous incidents of bacterial infection from knee and hip replacements each year. Hydrogel matrices are made using Michael-Type addition chemistry of derivatives of polyethylene glycol—a common, FDA approved polymer. Varying the ratio of polymeric functional groups and introducing photopatterned regions to previously homogenous hydrogels will increase local crosslink-density and prolong the release of antibiotics out of the gel system. A similar sustained release effect can be induced by suspending mPEG-PLGA (monomethoxypoly(ethyleneglycol)--poly(Lactide-co-glycolide)) nanoparticles loaded with antibiotics within the hydrogel matrix, creating a hybrid delivery system. By calculating the diffusion coefficient of each gel type and comparing drug release profiles, optimal gel properties can be selected for. Experimentation has shown sustained release can be achieved by increasing functional group ratio as well as curing via a two-step process. Hydrogel/nanoparticle gels exhibit a linear release curves that may lead to prolonged antibiotic release in patients and has potential to be used in many other administration applications.