Characterization of biocompatible collagen fibers--a promising candidate for cardiac patch

Type I and III collagens form the natural framework of the heart, and decellularized heart tissue revealed a fine weave of three dimensionally arranged collagen fibers. To mimic this structure for the fabrication of a cardiac patch, a process has been devised to extract solid atelopeptide collagen from bovine tendon while preserving its inherent tensile properties. Unlike chemical/enzymatic methods, which involve cellular disruption or reconstitution, this microbial collagen extraction process helps to get pure collagen fibers with their native properties intact. There is economy of extraction time, hence enhancement of productivity. The extracted collagen type I and III fibers have a D-periodicity of ∼67 nm, as commonly observed in collagen fibrils under transmission electron microscopy. Mechanical properties such as stress-strain relationship of the fibers were studied, and tensile strength was found to be 112.30 +/- 10.0 MPa. In vitro and in vivo studies reveal that the biocompatible fibers could be woven as a fleece to get a three-dimensional scaffold with good mechanical strength, not offered by soluble collagen preparations, suitable for tissue engineering applications, particularly as a cardiac patch.