This thesis addresses infection risks associated with orthopedic implants and focuses on challenges associated with tackling bacterial biofilms comprising antibiotic resistant organisms. Here, a proof-of-concept drug delivery system for prevention of implant-associated infections is presented. The aim of this study was to characterize two materials, PluronicF108andF127, by evaluating their physical and drug releasing properties to develop a controllable, thermosensitive on-demand drug delivery. The two hydrogels were characterized in terms of their rheological and micelle forming properties at various concentrations, using the inverted tube test and dynamic light scattering, respectively. Their stability was assessed by recording the weight loss ratio of the hydrogel and the drug release characteristics were assessed by monitoring the release of a hydrophobic dye. The cytotoxicity of the system was also tested in vitro.

The rheological assessment showed that the lower sol-gel temperature was in the range of 20-35◦ C and the upper gel-sol transition was in the range of 45-65◦ C, depending on the mass fraction concentration, hydrophilicity and the type of solvent. Furthermore, these characteristics also influence the critical micellar concentration, stability and therefore their release. The most stable hydrogel com position was 20 wt% Pluronic F127 in 1x phosphate-buffered saline (PBS). This study demonstrated a proof-of-concept of an on-demand drug releasing system com prising Pluronic F127 and polycaprolactone (PCL) as thermoresponsive components. The system showed that it can be used for single as well as intermittent release. Increasing the stability of the Pluronic, however, is further desirable. The system offers a non-invasive approach for an on-demand drug delivery. It requires, however, further work to enhance stability of the hydrogel to minimize passive release.