Following injuries resulting in a gap, tendons generally do not heal sufficiently because the defect does not fill with reparative tissue, or the resulting scar tissue is not functionally adequate. The objective of this study was to engineer a collagen-GAG (CG) copolymer to facilitate tendon regeneration. Previous work in our laboratory using similar porous resorbable analogs of extracellular matrix have led to regeneration of skin and peripheral nerve.
Matrices with controlled pore structure were produced by adapting the manufacturing technique developed in our laboratory for grafts with cylindrical geometry. CG suspensions contained within silicone elastomer tubes were frozen and lyophilized in a controlled manner. Quantitative optical microscopy was used to determine the percent porosity, average pore size, and pore orientation of the matrices.
The CG matrices, formed in silicone elastomer tubes, 3.8 mm in diameter, had average pore sizes ranging from 20 to 150 μm. his range of pore sizes was comparable to that obtained previously using a diameter of 1.5 mm.1 The average pore size did not appear to be strongly dependent on the tubing diameter. The homogeneity of the pore structure and the pore channel orientation could be controlled by adjusting the temperature of the bath used for freezing the CG suspension and the velocity with which the graft was immersed into the coolant bath.