title: Rheological properties of cross-linked hyaluronic acid dermal fillers.
abstract: OBJECTIVE
  Ha based dermal fillers in recent years aroused big interest in the area of cosmetic surgery for the rejuvenation of the dermis. There is not a ideal dermal filler (DF) for all applications and in commerce there are many types of DF that differ for their chemical-physical properties. So the aim of this paper is to correlate the rheological and physical properties of different DF to their clinical effectiveness.
  
  
  METHODS
  In this frame the samples have been subjected to oscillation dynamic rheological and steady shear measurements.
  
  
  RESULTS
  Our results demonstrate that the viscoelastic properties of different DF varie strongly also considering fillers of the same family. Furthermore it was found that the materials physical properties influence significantly the performance of dermal filler. In particular the clinical data appear to correlate with the concentration of the polymer and with the product between the concentration and the percent elasticity, so these should be crucial parameters for the clinical performance of DF.
  
  
  CONCLUSIONS
  So rheological data can be a tool to have an indication on the efficacy and longevity of DF but it has to be considered that production technology, in-vivo-conditions, injector skills and experience influence them also significantly.
authors: Division of General Surgery, University of Naples SUN, Naples, Italy.
authors: Stefano
authors: S
authors: Santoro
authors: Luisa
authors: L
authors: Russo
authors: Vincenzo
authors: V
authors: Argenzio
authors: Assunta
authors: A
authors: Borzacchiello
mesh_terms: D020405:Dermis; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry*; D008422:Materials Testing; D012212:Rheology / Q000379:methods; D017768:Skin, Artificial
chemical_list: D006820:Hyaluronic Acid