Bm hmscs

Human Bone Marrow Mesenchymal Stem Cells (BM-hMSCs) were purchased from PromoCell, 69126 Heidelberg, Germany, and expanded as previously described [13 (link)]. Briefly, BM-hMSCs were expanded in the presence of a growth medium (GM), a high glucose-based Dulbecco’s modified Eagle’s medium (DMEM) with 2% L-glutamine/penicillin-streptomycin/amphotericin B solution, 1 mM sodium pyruvate, MEM Non Essential Amino Acids Solution 1X and 10% fetal bovine serum (FBS) (referred as complete medium FBS) or 5% human platelet lysate (hPL) (referred as complete medium hPL) at 37 °C and 5% CO₂ in an incubator.

For the purpose of the study, commercial BM-hMSCs (PromoCell, Heidelberg, Germany) were expanded, as previously described [39 (link)]. All experiments were conducted with cells between passage 3 and 4.
Dry scaffolds were placed in a 24-well non-adherent plate (Corning, Sigma-Aldrich, St. Louis, MO, USA) for cell seeding. The cell concentration was adapted to have the required number of cells in a volume of 50μL of growth medium (GM), consisting of DMEM medium supplemented with FBS. A small drop (7 × 10⁵/50 μL viable BM-hMSCs) was slowly deposited on the top of each dry scaffold, waiting for 2 h at 37 °C for the complete absorption of the drop. After this time, 1 mL of GM was added to each well. The cell culture medium was changed three times per week. Each construct was analyzed on day 28 for cell viability and cell proliferation.
Additionally, we seeded BM-hMSCs in the PLA-CH(L), PLA-CH(M) and PLA-CH(H) to investigate the osteogenic differentiation capability of the scaffolds at day 28, following the protocol previously published [39 (link)]. Particularly, BM-hMSCs were grown in osteogenic medium (OM) for 28 days.