Ultra-rapid engineered collagen constructs tested in an in vivo nursery site

Collagen is a naturally occurring structural protein, highly conserved across species. Conventionally, tissue engineering aims to convert cell-seeded constructs into a tissue-like architecture with biomimetic function. However, cell-mediated remodelling of biomaterial scaffolds in vitro has proved to be slow, costly and difficult to control. We have recently developed a novel process for ultra-rapid engineering of tissue-like constructs without the need for cell-based remodelling. Using plastic compression of type I collagen gels, the densities of collagen and cells together with mechanical properties can be brought controllably to near-tissue levels in minutes rather than weeks/months. We have now implanted these constructs in a test site across intercostal spaces in a rabbit model designed to provide cyclical tensile loading in vivo, to test their integration, cell ingrowth and angiogenic response over 5 weeks. Post-implanted constructs were recovered and tested for host vascularization, inflammatory response and mechanical integrity.