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. The authors 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 plus PLLA, and carbon dioxide laser plus PLLA and 32 patients who underwent split-face treatments with MFR or MFR plus PLLA twice every 2 months. The Global Aesthetic Improvement Scale, Facial Laxity Rating scale of the whole face, the Echelle d'Evaluation Clinique des Cicatrices d'Acne grading scale of acne scars, and VISIA parameters on both treated sides were evaluated. Dermatologic 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 carbon dioxide laser in the mouse model. Thirty patients were treated with split-face MFR plus PLLA or MFR, revealing an improvement in VISIA wrinkle percentile (0.020) compared with the age-matched controls (0.000). The thickness of the dermis increased, whereas the fat layer did not change significantly. No adverse effects were observed. CONCLUSIONS: PLLA can be delivered through microchannels produced by MFR. PLLA enhances the efficacy of MFR for skin laxity without lipolysis.