title: Single-arm study for the characterization of human tissue response to injectable poly-L-lactic acid.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  To investigate human tissue response to injectable PLLA.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Skin Laser and Surgery Specialists of NY/NJ, New York, New York 10016, USA. drdavidgoldberg@skinandlasers.com
authors: David
authors: D
authors: Goldberg
authors: Adriana
authors: A
authors: Guana
authors: Andrea
authors: A
authors: Volk
authors: Elizabeth
authors: E
authors: Daro-Kaftan
mesh_terms: D000328:Adult; D005260:Female; D024022:Fibrillar Collagens / Q000187:drug effects*; D006801:Humans; D007249:Inflammation / Q000139:chemically induced; D007271:Injections, Intradermal; D019344:Lactic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D011091:Polyesters; D011108:Polymers / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D024022:Fibrillar Collagens; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)