Bio-Based Materials in Medicine Johnathan Marks and Blake Morell

Summary Background Motivation Basic Principles Examples Conclusion Further Research

Background Bio-based materials –Biomass derived (Type 1) Polysaccharides and proteins –Bio-monomer derived (Type 2) Polylactic acid (PLA) –Microorganism derived (Type 3) Polyhydrocyalkanoate (PHA), xanthan, and bacterial cellulose

Background Weber, C. J., "Biobased Packaging Materials for the Food Industry: Status and Perspectives"

Motivation Prevalence of chronic conditions –Cardiovascular disease –Diabetes –Arthritis –Neurodegenerative disease Biopolymers ideal for new biomedical devices –Effectively interface with human cells and tissue –Properties can be easily tuned to match properties of target tissues

Basic Principles Materials Engineering biology Processing Scale-up laboratory-moving.aspx water.com/web/index.php?option=com_content&view=article&id=58&lang=en

Biomedical Material Specifications Biocompatibility Performance requirements Non-toxic Non-inflammatory Shelf stability Usability Ratner, B. D., et al., "Biomaterials Science: An Introduction to Materials in Medicine"

Carbohydrates for Wound Closure Current problem: leakage from internal wounds –Need tissue adhesives Synthetic chemicals –Cyanoacrylates or glutaraldehyde Poor biocompatibility and performance problems Hydrogel tissue adhesives based on polysaccharide dextran

Carbohydrates for Wound Closure Dextran - polysaccharide of D-glucose units –Manufactured by bacteria Reaction: dextran aldehyde with multi-arm polyethylene glycol-amines makes cross-linked hydrogel Benefits: free of blood products, non-cytotoxic, capable of difficult incisions Bhatia, S. K., "Bio-Base Materials Step into the Operating Room"

Soy for Bone Repair Current problem: no bone reconstruction materials that meet requirements Soybeans: contain bioactive phytoestrogens –Induce differentiation of osteoblasts Santin, M. et al., "Soybean-based Biomaterials: Preparation, Properties and Tissue Regeneration Potential"

Soy for Bone Repair Synthesis - processed into films, membranes, porous scaffolds, and granules Benefits: ductility, bioactive, injectable Santin, M. et al., "Soybean-based Biomaterials: Preparation, Properties and Tissue Regeneration Potential"

Silk for Scaffolding Tissues Silk fibers are superior to synthetic high- performance fiber –Alanine - and glycine- rich protein consisting of repeating crystalline and amorphous regions –Good biocompatibility and biodegradability Silk scaffolds used to engineer cartilage, vascular, bone, and ligament tissues Liu, H., et al., "Electrospun sulfated silk fibroin nanofibrous scaffolds for vascular tissue engineering"

Bone Tissue Scaffold modified with RGD –Support cellular adhesion Mesenchymal stem cells –From bone marrow –Differentiate into bone, cartilage, or muscle Combine to form organized bone-like structure Mandal, B. B., et al., "High-strength silk protein scaffolds for bone repair"

Vascular Tissue Silk nanofibers manufactured by aqueous-based electrospinning Support the growth of aortic endothelial cells and coronary artery smooth-muscle cells Can be formed into tubes that withstand human blood pressures

Growth of Vascular Tissue Liu, H., et al., "Electrospun sulfated silk fibroin nanofibrous scaffolds for vascular tissue engineering"

Conclusion Search for materials with optimum compatibility with the human body Naturally sourced biopolymers are ideal for new biomedical devices Successful applications in wound closure, tissue repair, and tissue regeneration Field of bio-based materials for biomedical implants still developing

Further Research Detailed models of cellular proliferation and tissue repair Mechanistic study of interactions between biopolymers with cells, tissues, and organs Synthesize polymers from monomers obtained from agricultural resources Polymers derived from microbial production Reliable, cost-effective, scaled-up production

References Bhatia, S. K., "Bio-Based Materials Step into the Operating Room," American Institute of Chemical Engineers, pp (Sept. 2012). Weber, C. J., "Biobased Packaging Materials for the Food Industry: Status and Perspectives," European Union Directorate 12, Royal Veterinary and Agricultural Univ., Frederiksberg, Denmark (2000). Santin, M., and L. Ambrosio, "Soybean-Based Biomaterials: Preparation, Properties and Tissue Regenertation Potential," Expert Reviews in Medical Devices, 5 (3), pp (May 2008). Liu, H., et al., "Electrospun sulfated silk fibroin nanofibrous scaffolds for vascular tissue engineering," Biomaterials, 32 (15), pp (May 2011). Mandal, B. B., et al., "High-strength silk protein scaffolds for bone repair," Proceedings of the National Academy of Sciences of the United States of America, (May 2012).

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