BIOM 7432/8432: Advanced Biomaterials (Syllabus)

Course Description: Materials used in biomedical applications in relationship to corrosion, crack propagation, creep, and related topics; tissue ingrowth into materials

BIOM 4906: Tissue Engineering (Syllabus)

Course Description: To study the design, development, and implantation of tissue engineered components. Analysis of the basis for cell growth and differentiation, control of tissue development (in vivo & in vitro), models for tissue engineering, and transplantation of engineered cells and tissues. The emphasis of these analyses will be focused on the cardiovascular system (blood vessels and cardiac prostheses), musculoskeletal system (Bone, cartilage, and tendons), and skin

Immune Response Testing of Electrospun Polymers: An Important Consideration in the Evaluation of Biomaterials

Due primarily to cell sourcing issues, many in the field of tissue engineering have opted to create scaffolds that promote in situ regeneration, using the body as both the bioreactor and the cell source for the remodeling of scaffolds, resulting in the formation of native tissue. This practice raises many concerns, with the body’s immune response to such an implant often being neglected as a potential problem in preliminary design and biocompatibility testing. More importantly, what happens over time in terms of the immune responses as the biodegradable scaffold structures being utilized to promote in situ regeneration begin to degrade, forming structural fragments and degradation products? In summary, immune response evaluations are critical considerations that must be conducted when evaluating bioresorbable scaffolds. In addition, it is essential that these evaluations analyze materials for their potential dose-response and time-course effects on the various components of innate and acquired immunity

A comparative study of polyurethane nanofibers with different patterns and its analogous nanofibers containing MWCNTs

Tissue engineering is a multidisciplinary field that has evolved in various dimensions in recent years. One of the main aspects in this field is the proper adjustment and final compatibility of implants at the target site of surgery. For this purpose, it is desired to have the materials fabricated at the nanometer scale, since these dimensions will ultimately accelerate the fixation of implants at the cellular level. In this study, electrospun polyurethane nanofibers and their analogous nanofibers containing MWCNTs are introduced for tissue engineering applications. Since MWCNTs agglomerate to form bundles, a high intensity sonication procedure was used to disperse them, followed by electrospinning the polymer solutions that contained these previously dispersed MWCNTs. Characterization of the produced nanofibers has confirmed production of different non-woven mats, which include random, semi-aligned and mostly aligned patterns. A simultaneous and comparative study was conducted on the nanofibers with respect to their thermal stability, mechanical properties and biocompatibility. Results indicate that the mostly aligned nanofibers pattern presents higher thermal stability, mechanical properties, and biocompatibility. Furthermore, incorporation of MWCNTs among the different arrangements significantly improved the mechanical properties and cell alignment along the nanofibers

Electrospun Collagen: A Tissue Engineering Scaffold with Unique Functional Properties in a Wide Variety of Applications

Type I collagen and gelatin, a derivative of Type I collagen that has been denatured, can each be electrospun into tissue engineering scaffolds composed of nano- to micron-scale diameter fibers. We characterize the biological activity of these materials in a variety of tissue engineering applications, including endothelial cell-scaffold interactions, the onset of bone mineralization, dermal reconstruction, and the fabrication of skeletal muscle prosthetics. Electrospun collgen (esC) consistently exhibited unique biological properties in these functional assays. Even though gelatin can be spun into fibrillar scaffolds that resemble scaffolds of esC, our assays reveal that electrospun gelatin (esG) lacks intact α chains and is composed of proinflammatory peptide fragments. In contrast, esC retains intact α chains and is enriched in the α 2(I) subunit. The distinct fundamental properties of the constituent subunits that make up esC and esG appear to define their biological and functional properties

Platelet-Rich Plasma in Bone Regeneration: Engineering the Delivery for Improved Clinical Efficacy

Human bone is a tissue with a fairly remarkable inherent capacity for regeneration; however, this regenerative capacity has its limitations, and defects larger than a critical size lack the ability to spontaneously heal. As such, the development and clinical translation of effective bone regeneration modalities are paramount. One regenerative medicine approach that is beginning to gain momentum in the clinical setting is the use of platelet-rich plasma (PRP). PRP therapy is essentially a method for concentrating platelets and their intrinsic growth factors to stimulate and accelerate a healing response. While PRP has shown some efficacy in both in vitro and in vivo scenarios, to date its use and delivery have not been optimized for bone regeneration. Issues remain with the effective delivery of the platelet-derived growth factors to a localized site of injury, the activation and temporal release of the growth factors, and the rate of growth factor clearance. This review will briefly describe the physiological principles behind PRP use and then discuss how engineering its method of delivery may ultimately impact its ability to successfully translate to widespread clinical use

Electrospun Fibrinogen-Polydioxanone Composite Matrix: Potential for In Situ Urologic Tissue Engineering

Our objective is to demonstrate an electrospun fibrinogen-PDO (polydioxanone) composite scaffold will retain the superior cellular interaction of fibrinogen while producing a product with the functional strength needed for direct implantation. Fibrinogen-PDO composite scaffolds were electrospun with PDO ratios of 0% (pure fibrinogen), 10%, 20%, 30%, 40%, 50% and 100% (pure PDO) and disinfected using standard methods. Scaffolds were seeded with human BSM (bladder smooth muscle cells) and incubated with twice weekly media changes. Samples were removed at 7, 14 and 21 days for evaluation by collagen assay, scanning electron microscopy and histology. Cell seeding and culture demonstrated human BSM readily migrate throughout and remodel electrospun fibrinogen-PDO composite scaffolds with deposition of native collagen. Cell migration and collagen deposition increased with increasing fibrinogen concentration while scaffold integrity increased with increasing PDO concentration. Electrospun fibrinogen-PDO composite structures promote rapid cellular in-growth by human BSM while maintaining structural integrity. The fibrinogen to PDO ratio can be adjusted to achieve the desired properties required for a specific tissue engineering application. Our ultimate objective is to utilize this innovative biomaterial technology to produce an acellular, bioresorbable product that enables in situ tissue regeneration. While there is still much work to be done, these initial findings indicate fibrinogen-PDO composite scaffolds deserve further investigation

A Preliminary Study on the Potential of Manuka Honey and Platelet-Rich Plasma in Wound Healing

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration

A Preliminary Study on the Potential of Manuka Honey and Platelet-Rich Plasma in Wound Healing

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration