gms | German Medical Science

132. Kongress der Deutschen Gesellschaft für Chirurgie

Deutsche Gesellschaft für Chirurgie

28.04. - 01.05.2015, München

ASC-seeded alginate scaffolds and their angiogenic properties in vitro as a pre-model for autologous soft tissue replacement

Meeting Abstract

  • Christine Lämmle - Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Plastische Chirurgie und Schwerbrandverletzte, Bochum, Deutschland
  • Marina Handel - Hohenstein Institute, Hygiene, Umwelt und Medizin, Bönnigheim, Deutschland
  • Timo Hammer - Hohenstein Institute, Hygiene, Umwelt und Medizin, Bönnigheim, Deutschland
  • Frank Jacobsen - Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Plastische Chirurgie und Schwerbrandverletzte, Bochum, Deutschland
  • Marcus Lehnhardt - Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Plastische Chirurgie und Schwerbrandverletzte, Bochum, Deutschland
  • Dirk Höfer - Hohenstein Institute, Hygiene, Umwelt und Medizin, Bönnigheim, Deutschland
  • Tobias Hirsch - Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Plastische Chirurgie und Schwerbrandverletzte, Bochum, Deutschland

Deutsche Gesellschaft für Chirurgie. 132. Kongress der Deutschen Gesellschaft für Chirurgie. München, 28.04.-01.05.2015. Düsseldorf: German Medical Science GMS Publishing House; 2015. Doc15dgch626

doi: 10.3205/15dgch626, urn:nbn:de:0183-15dgch6264

Published: April 24, 2015

© 2015 Lämmle et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Introduction: Adipose-derived stem cells (ASCs) have been in the center of interest in medical research for the last decade. Characteristically, they can be differentiated into osteocytes, chondrocytes and adipocytes, and due to their uncomplicated extraction from adipose tissue, they are an excellent alternative to hematogenous stem cells. They deliver angiogenic factors to secure their own blood supply in tissues. Plastic surgeons therefore hope to find a benefit in using ASCs for the treatment of soft tissue defects. The challenge in medical practice is the combination of ASCs on a biocompatible scaffold that allows the exchange between ASCs and the surrounding vital tissue in vivo. Alginate is a clinically well-known biopolymer that can measure up to those requirements. The intention of this study was to produce an alginate-based scaffold, seeded with ASCs, to analyze its possible use in autologous soft tissue replacement.

Material and methods: First we established an alginate scaffold that was convenient in its shape, consistancy and reproducability. In order to explore its biocompatibility, we used well-known cytotoxicity assays, such as the MTT-assay for showing the scaffold’s inhibiting effect on the growth of mouse fibroblasts (L929). Porcine adipose-derived stem cells (pASCs) were isolated, characterized and differentiated into adipocytes for 21 days. The capacity of pASCs to promote angiogenesis was determined by a VEGF-ELISA. Furthermore, we analyzed this capacity in pASC-seeded alginate scaffolds on the CAM-angiogenesis model. This assay can be seen as a prestep to animal experiments and is undertaken on the oxygen exchange membrane of chicken embryos (chorioallantoic membrane = CAM). The angiogenic properties of pASC-seeded scaffolds were determined by counting embryonic blood vessels growing towards the scaffolds. In addition, we compared the angiogenic capacity of alginate scaffolds, seeded only with pASCs, and those in combination with collagen and pASCs.

Results: After successfully establishing a production process for alginate scaffolds and the isolation and characterization of pASCs, we showed that pASCs as well as humane (hASCs) and murine ASCs (M2), seeded into the scaffolds, differentiated into adipocytes. The alginate scaffolds showed cytotoxic effects in the MTT-assay that could be minimized by washing the scaffolds in double-destilled water. The VEGF-secretion of pASCs in a monolayer showed decrease during the 21-day-differentiation into adipocytes. The same could be shown in pASC-seeded alginate scaffolds. On day 7 of adipogenic differentiation, the possible point of implantation into vital tissue, the pASCs in the scaffolds showed a significantly higher VEGF-secretion than those in a monolayer. The CAM-angiogenesis-assay showed a significantly higher count of embryonic blood vessels using pASC-seeded alginate scaffolds than the negative controls. The same effect could be observed in scaffolds that were seeded with pASCs in combination with collagen. There was no significant difference in the collagen group and the pASC-only group.

Conclusion: The acquired data indicate that the ASC-seeded scaffolds were both angiogenically functional and might promote wound healing in vivo. The next step would be applying the scaffolds on an animal model to show the in vivo integration of the implants and to reveal a possible inflammation or rejection process in a vital organism.