title: Adipose-derived stem cells cultivated on electrospun l-lactide/glycolide copolymer fleece and gelatin hydrogels under flow conditions - aiming physiological reality in hypodermis tissue engineering.
abstract: BACKGROUND
  Generation of adipose tissue for burn patients that suffer from an irreversible loss of the hypodermis is still one of the most complex challenges in tissue engineering. Electrospun materials with their micro- and nanostructures are already well established for their use as extracellular matrix substitutes. Gelatin is widely used in tissue engineering to gain thickness and volume. Under conventional static cultivation methods the supply of nutrients and transport of toxic metabolites is controlled by diffusion and therefore highly dependent on size and porosity of the biomaterial. A widely used method in order to overcome these limitations is the medium perfusion of 3D biomaterial-cell-constructs. In this study we combined perfusion bioreactor cultivation techniques with electrospun poly(l-lactide-co-glycolide) (P(LLG)) and gelatin hydrogels together with adipose-derived stem cells (ASCs) for a new approach in soft tissue engineering.
  
  
  METHODS
  ASCs were seeded on P(LLG) scaffolds and in gelatin hydrogels and cultivated for 24 hours under static conditions. Thereafter, biomaterials were cultivated under static conditions or in a bioreactor system for three, nine or twelve days with a medium flow of 0.3ml/min. Viability, morphology and differentiation of cells was monitored.
  
  
  RESULTS
  ASCs seeded on P(LLG) scaffolds had a physiological morphology and good viability and were able to migrate from one electrospun scaffold to another under flow conditions but not migrate through the mesh. Differentiated ASCs showed lipid droplet formations after 21 days. Cells in hydrogels were viable but showed rounded morphology. Under flow conditions, morphology of cells was more diffuse.
  
  
  CONCLUSIONS
  ASCs could be cultivated on P(LLG) scaffolds and in gelatin hydrogels under flow conditions and showed good cell viability as well as the potential to differentiate. These results should be a next step to a physiological three-dimensional construct for soft tissue engineering and regeneration.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. Electronic address: Alfred.Gugerell@meduniwien.ac.at.
authors.forename: Alfred
authors.initials: A
authors.lastname: Gugerell
authors.affiliation: Department for Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria. Electronic address: Anne.Neumann@boku.ac.at.
authors.forename: Anne
authors.initials: A
authors.lastname: Neumann
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. Electronic address: Johanna.Kober@meduniwien.ac.at.
authors.forename: Johanna
authors.initials: J
authors.lastname: Kober
authors.affiliation: Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy. Electronic address: ltammaro@unisa.it.
authors.forename: Loredana
authors.initials: L
authors.lastname: Tammaro
authors.affiliation: Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Nobelstrasse 12, 70569 Stuttgart, Germany. Electronic address: Eva.Hoch@igvp.uni-stuttgart.de.
authors.forename: Eva
authors.initials: E
authors.lastname: Hoch
authors.affiliation: Biomaterials Department, INNOVENT e. V., Prüssingstraße 27B, 07745 Jena, Germany. Electronic address: MS@innovent-jena.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schnabelrauch
authors.affiliation: Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University Graz, Auenbruggerplatz 29, 8036 Graz, Austria. Electronic address: Lars.Kamolz@medunigraz.at.
authors.forename: Lars
authors.initials: L
authors.lastname: Kamolz
authors.affiliation: Department for Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria. Electronic address: Cornelia.Kasper@boku.ac.at.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Kasper
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. Electronic address: Maike.Keck@meduniwien.ac.at.
authors.forename: Maike
authors.initials: M
authors.lastname: Keck
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D018929:Cell Culture Techniques; D005109:Extracellular Matrix; D005780:Gelatin; D006801:Humans; D020100:Hydrogels; D011098:Polyglactin 910; D013234:Stem Cells / Q000166:cytology*; D040521:Subcutaneous Tissue; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D020100:Hydrogels; D011098:Polyglactin 910; D005780:Gelatin
keywords: Adipose-derived stem cells; Bioreactor; Electrospinning; Hydrogel; Scaffold; Skin tissue engineering