Results showed that MSCs were typical fibroblast-like and possessed a better proliferating capability; the activity of alkaline phosphatase (ALP) and the secretion of osteocalcin of MSCs were produced gradually and increased continuously; the cells seeded on three-dimensional porous nano-hydroxylapatite scaffolds adhered, proliferated and differentiated well.
The PLLA nanofibres displayed a significantly better proliferation rate, and enabled endothelial cells to proliferate in the monolayer.
The smaller pores in the matrix allowed cells to spread better and proliferate faster, while cells in the larger pores tended to form large aggregates and had lower proliferation rate.
In fact, CD15-positive cells, similar to CD133-positive cells, survive better and proliferate faster as compared with their negative counterparts (Supplementary Figure 3), indicating its potential to complement some part of CD133 function.
It has been demonstrated that a small subset of cancer cells with stem cell properties, referred to as 'cancer stem cells' (CSCs), survive intensive anticancer therapies better than proliferating progenitor cells or differentiated tumour cells (Dean et al, 2005).
Moreover, unlike fibroblasts, which proliferate better in 3% oxygen [ 27], keratinocytes proliferate better in 20% oxygen [ 57].
The selective importance of heme in tumor cell proliferation and function is also consistent with the previous observation that NSCLC cells require serum (containing heme) for maintenance and proliferation, whereas the normal lung cells survive and proliferate better with growth factors in the absence of serum [148, 149].
In our preliminary cell culture tests, osteoblast cells were found to attach and proliferate better on the chemically treated samples compared to the untreated alloys.
This finding is important as Fischbach-Teschl and Estroff showed previously that breast cancer cells can better adhere and proliferate on smaller, less-perfect HA crystals.
It may be because the stem cells proliferate better than cartilage cells, or because they are more receptive to molecular signals coming from the wounded tissues.
