Microneedling radiofrequency enhances poly-L-lactic acid penetration that effectively improves facial skin laxity without lipolysis

Background: Microneedle fractional radiofrequency (MFR) is commonly used for skin laxity treatment, and poly-L-lactic acid (PLLA) can stimulate collagen synthesis in the body. However, the synergy of their combination for skin rejuvenation has not been proven. We aimed to evaluate the combined efficacy of PLLA and MRF and the potential mechanism underlying skin laxity. Methods: This prospective, randomized study included C57BL/6 mice treated with MFR, MFR+PLLA, and CO 2 laser+PLLA and 32 patients who underwent split-face treatments with MFR or MFR+PLLA twice every 2 months. The global aesthetic improvement scale, Facial Laxity Rating scale of the whole face, ECCA grading scale of acne scars, and VISIA parameters on both treated sides were evaluated. Dermatological changes were measured by ultrasonography in the submental space, and adverse events were documented. Results: PLLA was delivered by channels produced by MFR but not CO 2 laser in the mice model. Thirty patients were treated with split-face MFRF+PLLA or MFRF, revealing an improvement in VISIA wrinkle percentile (0.020) compared with the age-matched controls (0.000). The thickness of the dermis increased, while the fat layer did not change significantly. No adverse effects were observed. Conclusions: PLLA can be delivered via microchannels produced by MFR. PLLA enhances the efficacy of MFR for skin laxity without lipolysis.