A facile tannic acid/gentamicin-loaded biodegradable silk fibroin lifting thread with robust mechanical and antibacterial properties

Fishbone-structured SF lifting threads were prototyped. • Glycerol/Ca 2+ regulation improved the mechanical properties of SF threads. • Tannic acid and gentamicin endowed the threads with antioxidant and antibacterial functions. • TA/GEN@SFs showed in vitro antibacterial activity against E. coli and S. aureus. • TA/GEN@SFs attenuated inflammatory infiltration and fibrous capsule formation in vivo . Facial thread lifting is widely employed in minimally invasive rejuvenation for its rapid recovery. However, its clinical acceptance is heavily limited by common complications, particularly local infections and severe inflammatory responses. Herein, a multifunctional silk fibroin (SF) lifting thread incorporating tannic acid (TA) and gentamicin (GEN) was fabricated using a custom-designed mold with a biomimetic fishbone architecture and was denoted as TA/GEN@SFs. TA/GEN@SFs exhibited excellent mechanical properties, with a breaking force of up to 40.00 ± 2.30 N and an elongation at break of 13.20 ± 0.98%. Moreover, TA/GEN@SFs showed significant antibacterial activity against Escherichia coli and Staphylococcus aureus , with inhibition zone diameters of 4.21 ± 0.33 mm and 5.71 ± 0.44 mm, respectively. In addition, TA/GEN@SFs achieved a free radical scavenging rate of 56.12 ± 3.31%, indicating notable antioxidant capability. Results from in vivo subcutaneous implantation further demonstrated that TA/GEN@SFs effectively modulated the wound microenvironment by suppressing excessive fibrosis and shortening the inflammatory phase. Overall, this study offers a promising strategy for creating functional implants in medical aesthetics. Download: Download high-res image (115KB) Download: Download full-size image