Hui Yu,Xiaojing Chen,Jie Cai,Dongdong Ye,Yuxiao Wu,Peifeng Liu
Long-term antibacterial medical dressings can prevent infection as skin wounds heal. In this study, we used the hydrophobic antibacterial drug amoxicillin as a model to prepare drug-loaded nanomicelles using a film dispersion–hydration method, and drug-loaded nanomicelles were coaxially electrospun into nanofiber to create a novel nanomicelle-in-nanofiber (NM-in-NF) drug delivery system. Scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of nanomicelles and nanofibers. Thermal property of as-prepared samples was tested using differential scanning calorimetry. The drug release behavior, cytotoxicity, and antibacterial properties of NM-in-NFs were examined in vitro to evaluate the system’s potential to be used in the treatment of skin wounds. Experimental results indicated that the novel NM-in-NF system had dual controlled release effect, which greatly reduced burst release and prolonged effective drug duration. Moreover, NM-in-NFs was also found to be safe and non-toxic, with a broad-spectrum antibacterial activity. It thus could potentially be used in long-term antibacterial medical dressings to treat skin wounds.
In this work, the tumor-targeted ultra-pH-responsive conjugates (PBA/Dex-g-OE) and nontargeted conjugates (Dex-g-OE) were successfully prepared and could easily self-assemble into stable micelles with lower CMC values in neutral aqueous solution. Transmission electron microscopy and dynamic light scattering measurement indicated that the resulting micelles have desirable size distribution and regular spherical shape. The PBA/Dex-g-OE micelles possessed high stability in physiological condition and were pH sensitive to both extracellular and intracellular acidic conditions. Doxorubicin (DOX) was efficiently loaded to give the DOX-loaded micelles (PBA/Dex-g-OE-DOX and Dex-g-OE-DOX) with the desirable drug loading contents. In vitro cellular uptake and growth inhibition assays suggested that PBA/Dex-g-OE-DOX micelles were more efficiently internalized by monolayer tumor cells and three-dimensional multicellular tumor spheroids (MCTS) than nontargeted micelles (Dex-g-OE-DOX), leading to the fast and complete destruction of MCTS in vitro.