This Small Business Innovation Research Phase I project will investigate manufacturability of the proposed innovation in the field of tissue engineering, overcome related research challenges, and estimate the market opportunity. We have developed, tested and patented novel process to induce self-assembly of molecular collagen into a number of collagen scaffolds with the organizations found in human tissues. The process is computer controlled and highly reproducible. The scaffolds with aligned-crimp fibrils have been implanted with and without cells into animals and have been found to induce the formation of new functional vasculature mostly aligned along the fibrils and maintain implanted cells viable for extended times in the ischemic tissue. We believe that our scaffolds could improve vascular function in conditions such as lymphedema and peripheral ischemia and be adaptable for diverse uses in tissue engineering. Therefore the goal of the project is to focus on the development of scalable manufacturing process for the preparation of nanofibrillar collagen scaffolds in a thread-like multi-luminal format and test them in-vitro and in-vivo in suitable animal models with and without plated cells. Scale-up system will include a novel collagen delivery device, semi-automated tooling to manufacture longer threads and both optical and laser inspection tools.
The broader impact/commercial potential of this project is based on the nature of our platform technology. Many current repair operations, such as rotator cuff repair and ligament replacement, use cadaver derived materials. Utilizing our approach, we can produce safe, strong, biocompatible replacements whose dimensions match those of the patient. Further, our materials should be less expensive. Stem cell applications in regenerative medicine have been limited by poor survival and lack of retention in target tissue. When delivered on our multi-luminal thread-like scaffolds, we achieve good survival and localization with the potential to enhance repair and facilitate stem cell application. The issue of cell and material retention in injectable gels, as well as vascularization and nutrient diffusion in three-dimensional scaffolds, remains a challenge. Advantages of our thread-like scaffolds are: large surface area for cell attachment due to their open, multi-luminal structure; fibril alignment directing cell alignment and migration; extended survival and maintenance of cells implanted on the threads; tunable mechanical properties to achieve the desired function and persistence. Our scaffolds will be used alone as well as loaded with cells for repair and regeneration of vascular and lymphatic systems and represent a significant step toward a major unmet medical need.
The goal of the NSF Phase I project was to develop key manufacturing modules for producing BioBridge™, a novel thread-like multiluminal collagen scaffold developed by Fibralign Corporation. BioBridge is designed to provide novel therapy for treating ischemia, a widespread and debilitating vascular disease with limited treatment options, by promoting and guiding revascularization. Our earlier collaboration with Stanford University showed that collagen membranes formed by aligned 30-nm diameter fibrils can orient cytoskeletal protein F-actin assembly in endothelial cells along the nanofibril direction and promote reduced adhesiveness of endothelial cells for monocytes, when compared to membranes formed by random or thick fibrils. Cell survival after implantation into normal or ischemic hindlimb tissue was markedly prolonged when endothelial cells were cultured and implanted on the aligned nanofibrillar scaffolds, in comparison to randomly oriented scaffolds. These results present a new approach for therapeutic cell delivery and for enhancement of cell survival in vivo. Prior to the project, we also demonstrated a method for creating a collagen membrane with the thickness of 1/60 of the human hair and forming it into a thread-like multiluminal scaffold such that all nanofibrills are aligned longitudinally along the thread axis. This nanopatterned scaffold provides high surface area for cell attachment, induces endothelial cell alignment and directs their migration along the fibrils. In addition, these scaffolds promote cell survival up to 14 days under ischemic conditions in vivo (published in Biomaterials, May, 2013). During the six month project, Fibralign successfully designed and built five planned modules that were used for precisely fabricating and characterizing the BioBridge thread-like scaffolds. These modules were then optimized and used to produce scaffolds that were tested by Stanford University both in vitro and in vivo (ischemia hind limb model) to confirm the survival and maintenance of primary ECs on Fibralign collagen scaffold as earlier published. The manufacturing modules completed under Phase 1 will be used going forward for development and clinical testing of implant devices to treat ischemic conditions, including peripheral arterial disease, by inducing guided revascularization of ischemic tissue. Manufacturing viability has been recently demonstrated. Fibralign used these modules to produce 150 scaffolds in support of a successful large animal study (unrelated to NSF) for treating secondary lymphedema. This break through study showed for the first time ever that nanofibrillar collagen scaffolds induced guided lymphatic regeneration, providing a potential treatment for a chronic and prevalent disease that currently has no cure. The findings have been accepted for presentation at the Symposium on Lymphedema Surgical Treatment (Barcelona, Spain) held on 5 March 2014 and the Gordon Research Conference: Molecular Mechanisms in Lymphatic Function & Disease held on 9-14 March 2014 (Lucca, Italy). Fibralign also successfully secured and completed a Phase 1B project during the second half of 2013 with an undisclosed industry partner to develop and fabricate multi-layer collagen scaffolds using Fibralignâ€™s Nanoweave™ technology. The project involved characterizing a range of process parameters, understanding their basic mechanical properties, and evaluating their suitability for a specific commercial application.