Gold Nanoparticle-Collagen Gels for Soft Tissue Augmentation.

Collagen soft tissue fillers suffer from fast reabsorption, which minimizes their use as a tissue-engineered construct. Extensive cross-linking can be utilized to extend longevity, but changes in microstructure and biomechanics can have deleterious effects. To enhance longevity while still achieving a natural microstructure, gold nanoparticles (AuNPs) were conjugated to fibrilized collagen and homogenized into an injectable form for use as a soft tissue filler. A long-term animal study in Yucatan swine was conducted to assess biocompatibility and longevity. Two formulations of the AuNP-collagen were compared to porcine cross-linked collagen and commercially available hyaluronic acid (HA). The results of the study demonstrated that the AuNPs may provide enhanced longevity over 6 months compared to HA and cross-linked collagen. Irritation scores indicated that the AuNP-collagen construct (AuNP-CC) demonstrated low irritation compared to the cross-linked collagen and HA while histology scores demonstrated good biocompatibility. Overall, it may be possible to utilize AuNPs to stabilize and increase the longevity of CC while still achieving biocompatibility.