15502-m-pleumeekers

particularly donor-dependent. (Figure 3) None of the constructs had mineralized or ossified. Also, vascularization within the construct, was never observed. Cells were more heterogeneously distributed in constructs containing either h AMSC/ b ACs or h BMSC/ b ACs compared to b ACs only. Collagen type II was abundantly present in constructs containing b AC or h BMSC/ b ACs. Again, hAMSC/bACs contained collagen type II in a donor-dependent manner. (Figure 3) Figure 3. Macroscopic appearance and immunohistochemical analyses of constructs containing h MSCs and/or b ACs, 8 weeks after subcutaneous implantation in mice. Macroscopic appearance (top row) of cartilage constructs, as well as a collagen type II immunohistochemical staining (bottom rows), 8 weeks after subcutaneous implantation. h AMSC = human Adipose-tissue-derived Mesenchymal Stem Cell ( n=3 experiments with 3 independent donors) ; h BMSC = human Bone-marrow-derived Mesenchymal Stem Cell ( n=3 experiments with 3 independent donors) ; b AC = bovine Articular Chondrocyte ( n=3 experiments with 3 pools of donors). Per experiment, 2 samples were used for analyses. In vivo , DNA- and sGAG-content were not detected in cell-free alginate constructs. (Data not shown) h AMSC/ b ACs and h BMSC/ b ACs contained similar quantities of cartilage matrix as constructs containing b ACs only. Moreover sGAG formation in co-cultures was independent of the origin of the h MSC-source used ( p =0.916). (Figure 4A) Collagen production demonstrated a similar trend, again without statistical significant differences between h AMSC/ b ACs and h BMSC/ b ACs ( p =1.000). (Figure 4B) Normalization of the data to their initially seeded primary ACs revealed more distinct differences between mixed-cell-type and single-cell-type populations: h AMSC/ b ACs and h BMSC/ b ACs produced significantly more sGAG and collagen per initially seeded primary ACs compared to b ACs ( h AMSC/ b ACs p <0.01 ; h BMSC/ b ACs p <0.05). (Figure 4) After subcutaneous implantation, the elastic modulus was 96 CHAPTER 5