Injectable Microbeads with a Thermo-Responsive Shell and a pH-Responsive Core as a Dual-Switch-Controlled Release System

An efficient delivery suspension should exhibit zero premature release behaviors during storage and possess the stimuli-responsive drug release characteristics at the target tissues. Stimuli-responsive delivery systems support on-demand controlled release activities that can carry drugs more effectively to the diseased tissues, maximizing therapeutic effectiveness and minimizing the toxicity of delivered drugs to the healthy tissues. Additionally, a related investigation has demonstrated that vancomycin at a low concentration has minimal effects on the replication of osteoblasts; nevertheless, very high concentrations can lead to cell death. The capacity of the developed MBs to differentiate between the in vivo environments of healthy and inflamed tissues was investigated using a mouse model. In the study, the right sides of the backs of mice were subcutaneously treated with Staphylococcus aureus, simulating post-operative wound infections, while the left sides of their backs were allowed untreated and served as healthy tissues.