Martin King

The Society for Biomaterials is an organization that connects individuals from industry, business, universities, the healthcare sector, and government to the field of biomaterials. A range of different disciplines, including materials science, biomedical engineering, medical textiles, microbiology, biotechnology, cell biology, pharmaceutical science and polymer science are some of the many areas that utilize biomaterials to improve the current standard of healthcare and the quality of life for patients suffering from disease or serious injuries. The goal of the Society for Biomaterials student chapter is to identify students interested in biomaterials, to generate student interest in and interaction with the biomaterials field, and to facilitate networking opportunities and activities for students seeking research, education, and professional development opportunities. The purpose of the Biomaterials Day event is to connect groups from across disciplines to gather and collaborate on advances in biomaterials used in healthcare and medical applications. It also aims to share the latest innovations in biomaterials, tissue engineering, and regenerative medicine being developed both at universities and in industry within the North Carolina area. The event includes oral presentations by invited speakers from North Carolina academia and industry, as well as oral and poster presentations by students and sponsors. This event has been created to initiate dialogue, give students the opportunity to showcase their work, and help establish networks and collaborations with all personnel involved in biomaterials, bridging researchers across departmental and institutional affiliations in order to advance the state of biomaterials technology within the North Carolina life sciences community. We look to the NC Biotechnology Center for their financial support. In addition, we ask that NC Biotechnology extends the publicity for this event by announcing it to its member organizations.

Biomaterials Day is a one-day event to connect groups from all disciplines to gather and collaborate on advances in biomaterials used in healthcare and medical applications, and give students opportunities to showcase their work and get inspiration, as well as help them establish networks and collaborations in the field.

This joint project proposal between North Carolina State University and the University of the Punjab in Pakistan has two overlapping goals. First, the textile sector is the backbone of Pakistan??????????????????s economy, and conventional textile production of fashion fabrics accounts for more than 95% of the output from its textile industry. However, there is another neglected and more profitable option for the future. This is the production of technical textiles or engineered textiles with a higher added value and profit margin. This proposal plans to harness over the next 3 years the technical expertise at the College of Textiles to establish a Technical Textiles Research Center or incubator at the University of the Punjab, with modern and flexible weaving and finishing equipment that will permit the development of technical textiles and particularly medical textiles for use in hospitals and clinics. By promoting a shift towards the production of technical and medical textiles, this will contribute significantly to the advancement of Pakistan??????????????????s economy. At the same time, the US healthcare sector needs immediate and significant assistance in controlling and reducing the current epidemic of hospital acquired nosocomial infections. The College of Textiles at North Carolina State University is already undertaking research to develop novel antimicrobial medical textile products based on marine natural biopolymers. This work needs to be expanded and strengthened by using the composite membranes, nanomaterials and research experience generated by researchers at the University of the Punjab in the area of sustainable natural biopolymers.

There are growing numbers of biomedical applications where the use of a resorbable biomaterial is increasingly important from the point of view of the patient, the surgeon, the device manufacturer and the healthcare system. For example, a growing number of clinical operations are now relying on resorbable sutures, stents, vascular devices and tissue engineering scaffolds. One of the main advantages of the resorbable device for the clinician and the healthcare system is that the patient does not require a second surgical operation for device removal. There are however, a number of disadvantages from the manufacturers point of view in processing, cleaning, sterilizing and storing a resorbable polymer that tends to resorb (i.e. degrade) whenever it is exposed to elevated temperatures and relative humidity. The purpose of this study is to select a couple of key fiber forming resorbable polymers and study their resorption profile experimentally during melt spinning and drawing in terms of their loss in molecular weight and loss in breaking strength. This experimental approach will be complemented by mathematical modeling to train an artificial neural network, to predict the change in molecular weight due to the melt spinning processing and subsequent thermal drawing conditions as well as predicting the resorption profile in terms of the loss in strength and loss in mass based on the final molecular weight and its distribution. It is anticipated that this will generate relationships between melt processing conditions, POY drawing conditions and the rate of resorption that can be applied to other resorbable polymers that experience the same resorption mechanism.

In response to the severe shortage of viable organs for transplantation, surgeons are eager for appropriate solutions to cure or regenerate natural tissues. A new paradigm and therapeutic approach known as regenerative medicine or tissue engineering (TE) involves growing the patient's cells outside the body usually in a bioreactor on a specially designed scaffold which gradually degrades during tissue regeneration. The success of this approach relies on the TE scaffold design and its three dimensional (3D) architecture of resorbable yarns to create a thick, porous and hierarchical structure. Our collaborators at Wake Forest Institute of Regenerative Medicine have identified two particular medical applications where there is an immediate clinical demand for a regenerative medicine approach and where there is an attractive commercial opportunity to provide a tissue engineering scaffold. The first of these involves creating the complex tissue matrix at a "Muscle-Tendon Junction" (MTJ). The second requires the fabrication of a tubular scaffold of less than 6 mm in diameter to serve as a coronary artery bypass or replacement. This proposal builds on our prior research that has demonstrated the proof-of-concept, that we can harness the latest textile spacer knitting technologies to fabricate three dimensional porous bioresorbable tissue engineering scaffolds that will eventually be manufactured, packaged, sterilized and ready for clinical use in a wide range of tissue engineering and regenerative medicine applications. Unlike other narrow-targeted scaffold designs, our scaffold has high design flexibility and can be used as a scaffold template for a variety of applications.

Implantable endovascular stent-grafts have become routine devices for the treatment of abdominal and thoracic aneurysms. Because they are fabricated from a tubular flexible non-permeable graft fabric or membrane, which is attached to a rigid stent, they can be collapsed, loaded into a sheath and delivered to the site of the aneurysm intra- or endovascularly by means of a delivery catheter. They are then expanded in situ so as to occlude the aneurysmal sac and ensure that it is isolated from normal pulsatile arterial blood pressure. However, given that such devices are permanent implants and should continue to function in a pulsatile blood flow environment for the life of the patient, the question of long-term biostability needs to be addressed. Examples of explanted specimens that have been retrieved from patients after a few months and up to several years indicate that in certain cases premature failure is caused by the abrasive action that can occur between the textile graft fabric and the metallic stent. There is a need to study this phenomenon in vitro so as to understand the contributing factors that lead to abrasion and wear. This will lead to the appropriate selection of materials and their structures that favor reduced levels of abrasion between the components and thus avoid such complications in future generations of endovascular stent-grafts.

With a view to the future demand for resorbable biomedical textiles and tissue engineering scaffold materials in the new emerging clinical therapy of regenerative medicine, Atex Technologies wishes to position itself as a leader in the design, engineering and production of resorbable biomedical textile structures. Atex Technologies Inc. wishes to start investing in the field of resorbable fiber-forming polymers. Given the current importance and clinical relevance of a wide range of hydrolytically catalyzed resorbable fiber-forming polymers, Atex Technologies Inc. needs to make a decision in the near future about which hydrolytically initiated resorbable polymers it plans to spin into yarns, fabricate, clean, finish, sterilize and package as biomedical textile products and how it is going to accomplish this in a low humidity "routine" manufacturing environment with the use of non-aqueous based yarn lubricants. This proposal enables Atex Technologies to make that decision.

Tengion Inc., a clinical-stage biotechnology company has pioneered the ?Organ Regeneration Platform? that enables the company to create proprietary autologous product candidates, such as the neo-urinary conduit, that harnesses the intrinsic regenerative pathways of the body to produce native-like organs and tissues, such as bladder tissue, for bladder cancer patients requiring urinary diversion following bladder removal. These autologous products seek to eliminate the need to utilize other tissues of the body, to avoid donor organs and the administration of anti-rejection medications. In order to achieve these goals a resorbable polyglycolic acid (PGA) nonwoven needle-punched scaffold material is purchased from Concordia Medical Inc. of Warwick, RI. During the processing of this scaffold material by Tengion Inc., a resorbable polylactide-co-glycolic acid (PLGA) coating is applied to improve epithelial cell attachment. The strength loss profile of this PGA + PLGA composite material has been found to depend on a number of key parameters, such as the temperature and pH of the environment, the presence of various enzymes and other chemical species, as well as the porosity and surface area of the scaffold structure. Therefore it is important for Tengion Inc. to have a good understanding of the mechanism and the rate of resorption of this PLGA coated PGA fibrous composite material, which can vary depending on the controllable storage, processing and sterilization conditions as well as the subsequent in vivo conditions. The process of resorption (or degradation) of the fibrous PGA component of the nonwoven scaffold and the associated changes in mechanical performance are most likely dependent on at least two different phenomena. First the tensile strength of the nonwoven needlepunched fibrous web is reduced by a loss of friction between adjacent fibers. This is a surface phenomenon that depends on the erosion of material in the outer layers of the fibers as well as changes in the surface morphology, (for example the formation of pores, pits, grooves and striations). Loss of surface friction during a tensile test of the nonwoven scaffold then leads to the fibers slipping past each other, fiber separation, loss of entanglement and web failure without fiber breakage. It is proposed in the second of two projects to generate a mathematical model that describes and predicts changes in the mechanical properties of this type of bonded nonwoven structure which will depend on the changes in the fibrous structure under applied loading, such as preferred fiber orientation and fiber curvature, and the assumptions about the extent of individual fiber freedom within the 3 dimensional web.

In response to the severe shortage of viable organs for transplantation, we are proposing to harness the latest fiber spinning, surface bioactivation and textile knitting technologies to prepare and fabricate 3 dimensional porous bioresorbable tissue engineering (TE) scaffolds that will be biocompatible and support the adhesion and proliferation of cells for use in the preparation of a range of different tissues and applications in regenerative medicine. At the present time the PI is working jointly with a number of medical and clinical partners at different universities and hospitals in North Carolina, the USA and Canada, who are enthusiastic about using textile scaffolds for growing a range of different cell lines, and thereby generating different types of tissues, such as those found in arteries, the bladder, liver, mouth (oral mucosa), pancreas and urethra. Discussions are already underway between the College of Textiles at NCSU and Wake Forest University?s Institute of Regenerative Medicine (WFIRM) to identify how standardized tissue engineering scaffolds might be produced commercially using established textile industry production methods and quality control systems. The motivation for this commercialization is to hasten the translation of such regenerative medical therapies from the bench top to the bedside in the shortest possible time, and thereby accelerate the regeneration of viable new organs within the patients themselves without having to rely on the current difficult and sometimes disappointing procedures associated with organ transplantation.

Given that there are currently about 90,000 patients in the USA waiting for organ transplantation and the annual healthcare cost of maintaining these patients is in excess of $500 billion, there is considerable interest within the healthcare community to develop viable tissue engineered substitutes using the regenerative medicine paradigm. Dr. Martin King in the College of Textiles at NCSU is applying the latest fiber spinning and textile fabrication technologies to the preparation of porous resorbable structures that will promote cell migration and proliferation through the thickness of the synthetic scaffold. Dr. David Gerber, who has much experience in the characterization, isolation and function of mature islets as well as pancreatic progenitor cell populations, will undertake the biological evaluation of these scaffolds an in vitro culture system. By integrating the work of these two laboratories the PI?s are creating a new multidisciplinary team that has diverse experience and a unique synergy for tackling projects with significant translational impact, such as the creation of new drug discovery assays and the development of cell and tissue based therapies.