title: Biocompatibility of agarose gel as a dermal filler: histologic evaluation of subcutaneous implants.
abstract: BACKGROUND
  The search for safe and effective tissue fillers has been an ongoing effort in plastic and cosmetic surgery over recent decades. Biocompatibility is a prerequisite for any substance to be used as an implant material, and potential biomaterials need to be characterized by histologic evaluation of tissue responses. Collagen is a well-known tissue filler. Agarose gel is widely used in bioengineering. Both products are considered biocompatible. The purpose of this study was to evaluate the bioactivity of agarose gel as a dermal filler compared with collagen.
  
  
  METHODS
  Tissue responses to agarose gel and collagen were evaluated in a rat in vivo model (n = 96). Four groups were evaluated: group 1 (n = 24), rats with agarose gel implants; group 2 (n = 24), rats with collagen implants; group 3, a placebo group (n = 24); and group 4, a control group (n = 24). Responses and biocompatibility were assessed by histopathologic and histomorphometric evaluation at 1 week to 8 months after implantation.
  
  
  RESULTS
  Agarose gel showed marked bioactivity and biodegradation, although the implants integrated well into tissues: newly formed collagen bands were observed inside the implants and no granulomas were detected. Collagen implants showed low cell infiltration and a significant loss of product over time.
  
  
  CONCLUSIONS
  Agarose gel is a biocompatible product that can be considered for use as a tissue filler. Further investigation is required to assess its long-term efficacy and safety.
authors: Santiago de Compostela, Spain From the Departments of Plastic and Reconstructive Surgery and Clinical Epidemiology, Clinical University Hospital, Santiago de Compostela, and the Departments of Experimental Dermatology and Morphological Sciences, Santiago de Compostela University, School of Medicine.
authors: Sergio
authors: S
authors: Fernández-Cossío
authors: Alvaro
authors: A
authors: León-Mateos
authors: Francisco Gude
authors: FG
authors: Sampedro
authors: María Teresa Castaño
authors: MTC
authors: Oreja
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage*; D003094:Collagen / Q000008:administration & dosage; D005782:Gels; D008297:Male; D008422:Materials Testing; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D012685:Sepharose / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D001672:Biocompatible Materials; D005782:Gels; C064154:NuSieve agarose; D003094:Collagen; D012685:Sepharose