title: Asymmetric PDLLA membranes containing Bioglass® for guided tissue regeneration: characterization and in vitro biological behavior.
abstract: OBJECTIVE
  In the treatment of periodontal defects, composite membranes might be applied to protect the injured area and simultaneously stimulate tissue regeneration. This work describes the development and characterization of poly(d,l-lactic acid)/Bioglass® (PDLLA/BG) composite membranes with asymmetric bioactivity. We hypothesized that the presence of BG microparticles could enhance structural and osteoconductivity performance of pure PDLLA membranes.
  
  
  METHODS
  The membranes were prepared by an adjusted solvent casting method that promoted a non-uniform distribution of the inorganic component along the membrane thickness. In vitro bioactive behavior (precipitation of an apatite layer upon immersion in simulated body fluid, SBF), SEM observation, FTIR, swelling, weight loss and mechanical properties of the developed biomaterials were evaluated. Cell behavior on the membranes was assessed using both human bone marrow stromal cells and human periodontal ligament cells.
  
  
  RESULTS
  Just the BG rich face of the composite membranes induced the precipitation of bone-like apatite in SBF, indicating that this biomaterial exhibit asymmetric osteoconductive properties. SEM images, DNA content and metabolic activity quantification revealed an improved cell adhesion and proliferation on the composite membranes. Composite membranes also stimulated cell differentiation, mineralization, and production of extracellular matrix and calcium nodules, suggesting the positive effect of adding the bioactive microparticles in the PDLLA matrix.
  
  
  CONCLUSIONS
  The results indicate that the proposed asymmetric PDLLA/BG membranes could have potential to be used in guided tissue regeneration therapies or in orthopedic applications, with improved outcomes.
authors: 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Guimarães, Portugal.
authors: Ana I
authors: AI
authors: Leal
authors: Sofia G
authors: SG
authors: Caridade
authors: Jinling
authors: J
authors: Ma
authors: Na
authors: N
authors: Yu
authors: Manuela E
authors: ME
authors: Gomes
authors: Rui L
authors: RL
authors: Reis
authors: John A
authors: JA
authors: Jansen
authors: X Frank
authors: XF
authors: Walboomers
authors: João F
authors: JF
authors: Mano
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000704:Analysis of Variance; D001031:Apatites / Q000737:chemistry; D001672:Biocompatible Materials / Q000138:chemical synthesis*; D001861:Bone Regeneration / Q000502:physiology*; D002118:Calcium / Q000032:analysis; D018929:Cell Culture Techniques; D002516:Ceramics / Q000737:chemistry*; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D010518:Periodontitis / Q000628:therapy; D011091:Polyesters / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; C022107:Bioglass; D011091:Polyesters; D000469:Alkaline Phosphatase; D002118:Calcium