Discussion
Our findings suggest that using parathyroid hormone or lactoferrin as a singular factor to promote tendon healing may not be of benefit, but for use in tendon-bone healing there would be no detrimental effect on the tendon itself.
Methods
Tenocyte proliferation and collagen production were assessed by alamarBlue® and Sirius red as-says, respectively. To assess tenocyte trans-differentiation, changes in the expression of genes important in tenocyte, chondrocyte and osteoblast biology were determined using real-time PCR.
Results
Parathyroid hormone and lactoferrin had no effect on tenocyte growth or collagen production, with minimal changes in gene expression and no detrimental effects observed to suggest trans-differentiation away from tendon cell behaviour. Tenogenic factors PDGF, IGF-1 and TGF all increasetenocyte collagen production, however, the gene expression data suggests that PDGF promotes severe de-differentiation of the tenocytes.