Single-Arm Study for the Characterization of Human Tissue Response to Injectable Poly-L-Lactic Acid


  • This study was funded by sanofi-aventis U.S. LLC Inc. Editorial support for this sanofi-aventis–funded article was provided by Peloton Advantage, LLC. Dr. Guana is an employee of Sanofi, the sponsor of the study, as Senior Director, GT Allergy and Dermatology, USMA. The authors were fully responsible for the content, editorial decisions, and opinions expressed in the current article. No author received an honorarium related to the development of this manuscript.

Address correspondence and reprint requests to: David Goldberg, MD, Director, Skin Laser & Surgery Specialists of NY/NJ, The Galleria, 115 E. 57th Street, Suite 710, New York, NY 10016, or e-mail:



Injectable poly-L-lactic acid (PLLA) is a synthetic polymer indicated for the correction of facial wrinkles and folds. Animal studies have shown that implantation of PLLA stimulates collagen synthesis; human studies have been limited.


To investigate human tissue response to injectable PLLA.

Methods and Materials

In this exploratory single-arm, open-label study, 14 healthy subjects were administered injectable PLLA; punch biopsies at 3, 6, and 12 months were analyzed for qualitative and quantitative changes from baseline in collagen types I and III and assessed for inflammatory responses.


Quantitative and qualitative increases were observed for collagen types I and III at 3 and 6 months and were statistically significant for collagen type I at 3 and 6 months. Post hoc analyses at 12 months showed nominal collagen increases but were hindered by technical difficulties. The degree of inflammatory response was similar to baseline at 3, 6, and 12 months; all subjects were found to have no or mild inflammation after baseline. Adverse events were mild and among those reported previously.


Results of this study in humans found statistically significant stimulation of collagen type I with no or mild inflammatory response after administration of injectable PLLA.