title: In vivo and in vitro evaluation of an Acetobacter xylinum synthesized microbial cellulose membrane intended for guided tissue repair.
abstract: BACKGROUND
  Barrier materials as cellulose membranes are used for guided tissue repair. However, it is essential that the surrounding tissues accept the device. The present study histologically evaluated tissue reaction to a microbial cellulose membrane after subcutaneous implantation in mice. Furthermore, the interaction between mesenchymal stem cells and the biomaterial was studied in vitro to evaluate its ability to act as cellular scaffold for tissue engineering.
  
  
  METHODS
  Twenty-five Swiss Albino mice were used. A 10 x 10 mm cellulose membrane obtained through biosynthesis using Acetobacter xylinum bacteria was implanted into the lumbar subcutaneous tissue of each mouse. The mice were euthanatized at seven, 15, 30, 60, and 90 days, and the membrane and surrounding tissues were collected and examined by histology.
  
  
  RESULTS
  A mild inflammatory response without foreign body reaction was observed until 30 days post-surgery around the implanted membrane. Polarized microscopy revealed that the membrane remained intact at all evaluation points. Scanning electron microscopy of the cellulose membrane surface showed absence of pores. The in vitro evaluation of the interaction between cells and biomaterial was performed through viability staining analysis of the cells over the biomaterial, which showed that 95% of the mesenchymal stem cells aggregating to the cellulose membrane were alive and that 5% were necrotic. Scanning electron microscopy showed mesenchymal stem cells with normal morphology and attached to the cellulose membrane surface.
  
  
  CONCLUSIONS
  The microbial cellulose membrane evaluated was found to be nonresorbable, induced a mild inflammatory response and may prove useful as a scaffold for mesenchymal stem cells.
authors.affiliation: Department of Veterinary Surgery and Anesthesiology, São Paulo State University, Botucatu, SP, Brazil. periclesmendes@hotmail.com
authors.forename: Péricles Nóbrega
authors.initials: PN
authors.lastname: Mendes
authors.forename: Sheila Canevese
authors.initials: SC
authors.lastname: Rahal
authors.forename: Oduvaldo Câmara Marques
authors.initials: OC
authors.lastname: Pereira-Junior
authors.forename: Viciany Erique
authors.initials: VE
authors.lastname: Fabris
authors.forename: Sara Lais Rahal
authors.initials: SL
authors.lastname: Lenharo
authors.forename: João Ferreira
authors.initials: JF
authors.lastname: de Lima-Neto
authors.forename: Fernanda
authors.initials: F
authors.lastname: da Cruz Landim-Alvarenga