  Poly-dl-lactic acid (PDLLA) was blended with type I collagen to attempt to
overcome the instantaneous gelation of electrospun collagen scaffolds in
biological environments. Scaffolds based on blends of type I collagen and PDLLA
were investigated for material stability in cell culture conditions (37
{\deg}C; 5% CO2) in which post-electrospinning glutaraldehyde crosslinking was
also applied. The resulting wet-stable webs were cultured with bone marrow
stromal cells (HBMSC) for five weeks. Scanning electron microscopy (SEM),
confocal laser scanning microscopy (CLSM), Fourier transform infra-red
spectroscopy (FTIR) and biochemical assays were used to characterise the
scaffolds and the consequent cell-scaffold constructs. To investigate any
electrospinning-induced denaturation of collagen, identical PDLLA/collagen and
PDLLA/gelatine blends were electrospun and their potential to promote
osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios
of 40/60, 60/40 and 80/20 resulted in satisfactory wet stabilities in a humid
environment, although chemical crosslinking was essential to ensure long term
material cell culture. Scaffolds of PDLLA/collagen at a 60:40 weight ratio
provided the greatest stability over a five-week culture period. The
PDLLA/collagen scaffolds promoted greater cell proliferation and osteogenic
differentiation compared to HMBSCs seeded on the corresponding PDLLA/gelatine
scaffolds, suggesting that any electrospinning-induced collagen denaturation
did not affect material biofunctionality within 5 weeks in vitro.
