Self-reinforced silk nanofibrils networks enable ultrafine fibroin monofilament sutures applied in minimally invasive surgery.

Summary

The authors created ultrafine, strong silk fibroin monofilament sutures by embedding β-sheet-rich silk nanofibrils into RRSF and inducing a highly oriented self-reinforcing network via water-immersion stretching. The sutures met USP 9-0 standards (39.38 μm diameter, 0.31 N tensile strength), showed antibacterial activity and 43% 30-day degradation, and reduced inflammation and scarring in animal models.

Key Findings

• 0.1 wt% silk nanofibrils plus a 2.5× stretching multiplier increased tensile strength by 33% versus no SFNF.
• Achieved USP 9-0 monofilament sutures (39.38 μm diameter, 0.31 N tensile strength).
• Demonstrated antibacterial activity and 43.09% degradation within 30 days.
• Animal studies showed improved wound closure, reduced inflammation, and minimized scarring.
• Fluorescence imaging and simulations confirmed a highly oriented, self-reinforcing SFNF network.

Clinical Implications

Ultrafine but strong monofilament sutures could improve cosmetic outcomes in microsurgery by reducing incision size and scarring, while antibacterial activity may lower infection risk.

Limitations

• Preclinical study without human clinical trials.
• Long-term durability and degradation beyond 30 days were not assessed.

Future Directions

Scale-up manufacturing, suture handling ergonomics, and first-in-human trials in microsurgery and aesthetic procedures; evaluation of long-term performance and infection outcomes.