The biological basis for poly-L-lactic acid-induced augmentation

J Dermatol Sci. 2015 Apr;78(1):26-33. doi: 10.1016/j.jdermsci.2015.01.012. Epub 2015 Feb 7.


Background: Granulomatous reactions to poly-L-lactic acid (PLLA)-based filler have been described previously. Neither the biological background of these partly late-onset reactions or the desired augmenting effect of PLLA has been studied to date. Histological studies have revealed foreign body reactions and foreign body giant cell formation.

Objective: The aim of this study was to increase our knowledge about the biological mechanisms behind the augmenting effect of PLLA-based filler.

Methods: We characterised the cell infiltrate and collagen type of PLLA-treated tissue by immunofluorescence staining. The expression of genes related to collagen metabolism was determined.

Results: CD68(+) macrophages were found next to PLLA. CD90(+) fibroblasts were found alongside. αSMA-positive structures indicated myofibroblasts and neovascularisation. Substantial collagen type III deposition was detected next to PLLA particles and collagen type I was found at the periphery of PLLA encapsulations. mRNA expression for collagen type I and III transcripts, as well as for TGFβ1 and TIMP1, was upregulated significantly.

Conclusion: PLLA-induced augmentation is most likely based on capsule formation orchestrating macrophages, (myo-)fibroblasts, and collagen type I and III fibres. We observed considerably slower degradation of PLLA particles than described previously. Thus PLLA particles were still retrievable 28 months after subcutaneous application.

Keywords: (Myo-)fibroblasts; Collagen type I; Collagen type III; Filler; Macrophages; Poly-l-lactic acid.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biopsy
  • Collagen Type I / genetics
  • Collagen Type I / metabolism
  • Collagen Type III / genetics
  • Collagen Type III / metabolism
  • Cosmetic Techniques*
  • Dermal Fillers / administration & dosage*
  • Dermal Fillers / adverse effects
  • Dermal Fillers / metabolism
  • Female
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Germany
  • Humans
  • Immunohistochemistry
  • Injections, Subcutaneous
  • Lactic Acid / administration & dosage*
  • Lactic Acid / adverse effects
  • Lactic Acid / metabolism
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Macrophages / pathology
  • Middle Aged
  • Myofibroblasts / drug effects
  • Myofibroblasts / metabolism
  • Myofibroblasts / pathology
  • Polyesters
  • Polymers / administration & dosage*
  • Polymers / adverse effects
  • Polymers / metabolism
  • Prospective Studies
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Subcutaneous Tissue / drug effects*
  • Subcutaneous Tissue / metabolism
  • Subcutaneous Tissue / pathology
  • Time Factors
  • Tissue Inhibitor of Metalloproteinase-1 / genetics
  • Transforming Growth Factor beta1 / genetics
  • Up-Regulation


  • Collagen Type I
  • Collagen Type III
  • Dermal Fillers
  • Polyesters
  • Polymers
  • RNA, Messenger
  • TGFB1 protein, human
  • TIMP1 protein, human
  • Tissue Inhibitor of Metalloproteinase-1
  • Transforming Growth Factor beta1
  • Lactic Acid
  • poly(lactide)