A UV-triggered superhydrophobic-to-superhydrophilic smart composite for preventing bacterial adhesion and enabling on-demand drug release

A smart material with antibacterial adhesion and controlled drug release. • The smart material can avoid secondary pollution. • The smart material can prevent premature release. Smart drug delivery systems have attracted broad attention in biomedicine and related fields. However, existing drug delivery systems face critical issues including premature drug release and easy bacterial adhesion on the surface leading to secondary contamination. In this study, we designed a smart composite material (SSTP) that integrates resistance to bacterial adhesion with controlled drug release. Porous polylactic acid (PPLA) was used as the drug carrier, and superhydrophobic TiO₂ (S-TiO₂) was spray-deposited onto the PPLA surface to fabricate SSTP, which exhibited a UV-triggered transition from a superhydrophobic state to a superhydrophilic state. Initially, SSTP is in a “closed” anti-contamination state characterized by superhydrophobicity and low adhesion, exhibiting a contact angle (CA) of approximately 152 ± 2° and a roll-off angle (RA) of approximately 9 ± 2° This state effectively prevents bacterial contamination and premature drug release. Upon UV irradiation, SSTP transitions from the superhydrophobic “closed” state to a superhydrophilic “open” state, thereby facilitating drug release. Furthermore, SSTP exhibits good biocompatibility, indicating its potential for biomedical applications. The SSTP designed and fabricated in this study offers new insights into the design of novel smart antibacterial materials. Download: Download high-res image (231KB) Download: Download full-size image A smart material capable of resisting bacterial contamination and enabling controlled drug release was prepared. The material initially exists in a superhydrophobic and low-adhesion state, effectively preventing bacterial contamination. Upon ultraviolet irradiation, it undergoes a transition from a superhydrophobic to a superhydrophilic state, enabling controllable drug release. The fabrication of this material mitigates secondary bacterial contamination and premature release of the drug.