Construction and drug release performance of thermosensitive copolymer-modified hollow mesoporous silica and the composite nanofibers

Traditional drug-loaded nanofibers face challenges such as unstable drug loading and excessively rapid release. In light of these issues, this study employs a thermosensitive copolymer (P(NIPAM-co-AM)) to coat hollow mesoporous silica nanoparticles (HMSN), incorporating them as drug carriers in conjunction with poly(ε-caprolactone) (PCL) nanofibers. The drug release and antibacterial performance of the composite nanofiber membrane were investigated. Firstly, the HMSN surface was functionalized through free radical polymerization by grafting a copolymer of isopropylacrylamide (NIPAM) and acrylamide (AM) (P(NIPAM-co-AM)). Hydrophobic drug ciprofloxacin (CIP) was loaded into the modified nanoparticles (P(NIPAM-co-AM)-HMSN or PHMSN). The analysis of the microstructure, composition, and temperature-responsibility of the drug-loaded particles were performed using SEM, TEM, TG, BET analysis, FTIR, UV-Vis spectroscopy, etc. Blending PCL with drug-loaded PHMSN, a composite fibrous membrane (CIP@PHMSN-PCL) was fabricated using electrospinning. CIP@PHMSN-PCL exhibited temperature-stimulated drug releasing, with cumulative release rates of CIP reaching 90.78% and 72.67% at 45℃ and 25℃ after 72 h, respectively. The Korsmeyer-Peppas model apply described the drug release kinetics, suggesting the diffusion as the primary mechanisms for drug release from the composite fiber membrane. At 45℃, the drug-loaded fiber membrane exhibited a 100% inhibition rate against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). At 25℃, the inhibition rates were 92.34% and 95.83% against E. coli and S. aureus, respectively, demonstrating temperature-dependent drug release performance of the CIP@PHMSN-PCL membrane. In summary, the drug-loaded PHMSN composite nanofiber membrane exhibits temperature-regulated drug release functionality and excellent antibacterial activity, holding potential application value in the biomedical field.