Publication
Neocartilage Formation in 1 g, Simulated, and Microgravity Environments: Implications for Tissue Engineering
Publisher:
Mary Ann Liebert Inc
Date:
05-2010
DOI:
10.1089/TEN.TEA.2008.0624
Abstract: The aim of this study was to analyze and compare the deposition of cartilage-specific extracellular matrix components and cellular organization in scaffold-free neocartilage produced in microgravity and simulated microgravity. Porcine chondrocytes were seeded (100 x 10(6)/mL) into cylindrical culture chambers (n = 8) and cultured in the following environments: (i) microgravity during the Flight 7S (Cervantes mission) on the International Space Station (ISS), (ii) simulated microgravity in a random positioning machine (RPM), and (iii) normal gravity (1 g, control). After 16 days, each neocartilage tissue was processed for histology, immunohistochemistry, quantitative real-time reverse transcriptase-polymerase chain reaction, and histomorphometric analysis. Weaker extracellular matrix staining of ISS neocartilage tissue was noted compared with both Earth-cultivated tissues. Higher collagen II/I expression ratios were observed in ISS s les compared with control tissue. Conversely, higher aggrecan/versican gene expression profiles were seen in control 1 g s les compared with microgravity s les. Cell density produced in microgravity was significantly reduced compared with the normal gravity neocartilage tissues. Tissue cultivated on the RPM showed intermediate characteristics compared with ISS and 1 g conditions. These data indicate that the RPM system does not sustain microgravity. Although microgravity impacts the development of in vitro generated cartilage, simulated microgravity using the RPM may be a useful tool to produce cartilaginous tissue grafts with fewer cells.