Bone cell interaction with extracellular matrix (ECM) microenvironment is of critical importance when engineering surface interfaces for bone regeneration. In this work layer-by-layer films of type I collagen (Coll), the major constituent of bone ECM, and heparin (hep), a glycosaminoglycan, were assembled on poly(L-lactic acid) (PLLA) substrates to evaluate the impact of the biomacromolecular coating on cell activity. The surface modification of PLLA demonstrated that the hep/coll multilayer is stable after 10 bilayers (confirmed by contact angle, infrared spectroscopy, and morphological-analysis). This simple approach provided novel information On the effect of heparin, on type I collagen hierarchical :organization and subsequent cell response of osteoblast-like (MC3T3-E1) and human bone marrow-derived mesenchymal stein cells (hMSCs). Interestingly, the number of deposited heparin layers (1 or 10) appeared to play an important role in the self-assembly of collagen into fibrils, stabilizing the fibrous collagen layer; and potentially impacting hMSCs activity.
