A Hybrid Gel of Hyaluronic Acid and Poly-L-Lactic Acid for Nasolabial Folds by Ligament-targeted Injection

Background: Nasolabial folds (NLFs) significantly impact facial aesthetics. A novel filler combining cross-linked sodium hyaluronate with poly- L -lactic acid-b-polyethylene glycol microspheres (PLLA-b-PEG/HA) has shown potential. This study evaluated the efficacy and safety of the PLLA-b-PEG/HA filler for NLF correction with an innovative ligament-targeted injection technique. Methods: This retrospective study was reported in accordance with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Thirteen participants presenting with mild to severe bilateral NLFs (WSRS scores 2-4), were examined between December 2022 and February 2023. Treatment involved injections of PLLA-b-PEG/HA at the temporal, preauricular, zygomatic, and mandibular ligaments. Efficacy was assessed via the WSRS, Global Aesthetic Improvement Scale, FACE-Q satisfaction with cheeks scale, and participants’ satisfaction during a 12-month follow-up period. Results: At the 12 months, a statistically significant improvement was observed in the mean WSRS score, which decreased from 3.00 ± 0.71 to 1.85 ± 0.90 ( P < 0.05), with a response rate of 84.62%. The improvement was sustained through the 12-month period. Significant enhancements were also noted in both the FACE-Q and Global Aesthetic Improvement Scale scores at each posttreatment follow-up visit, with participants reporting high levels of satisfaction. The PLLA-b-PEG/HA filler demonstrated an acceptable safety profile, with only 1 case of transient mild erythema and edema reported. Conclusions: These preliminary findings suggest that the PLLA-b-PEG/HA filler, combined with a ligament-targeted injection technique, shows promising efficacy and a favorable safety profile for NLF correction over 12 months.