Samuel Hudson

Project Title: A Medical Textile for Comprehensive Wound Care: A laminated Multifunctional Electrospun Fabric that is Hemostatic, Anti-Inflammatory and Anti-Microbial Hemostasis is the physiological process to arrest bleeding and minimize blood loss from damaged blood vessels. Hemostasis can be accelerated by contact of the blood with foreign materials. The goal of this research is to develop and evaluate materials which could be used in hemostatic wound dressings to arrest the heavy bleeding associated with traumatic wounds. This would be accomplished by the novel approach of using a composite material to create an in situ artificial blood clot. A mesh of micron scale fibers to mimic the fibrous network formed by the self association of fibrin, would be combined with a material or agent that would lead to the gelation of the soluble blood proteins. This would lead to the in situ formation of a blood clot, at a more rapid rate than could naturally occur by the enzymatic processes associated with natural blood clot formation. The mesh material would be obtained by the electrospining of liquid crystal cellulose acetate solutions, which lead to fibers of the dimensions of the naturally occurring fibrin fibers and would have tensile strength associated with liquid crystal processed fibers, unlike the electrospun fibers of isotropic solutions. This mesh would be blended with and embedded with an agent that would gel the soluble blood proteins by cross linking reactions with the pendent thiol and amino groups found in these proteins. For example, fibroinogen, the precursor protein to the fibrin fibers found in a natural blood clot has at least 26 thiol groups per chain. Biopolymers such as chitosan, which already has the natural property of causing the agglutinization of erthrocyte (red blood) cells and activating platelet cells, would be further modified to lead to the cross linking and subsequent gelation of the soluble blood proteins, such a fibronogen and albumin. These modifications would be accomplished by synthesizing chitosan derivatives containing dangling aldehyde groups and other groups associated with selective reactions with the thiol group. These materials would be further enhanced by combing them with amylose, modified to be highly water absorbent. By adsorbing the water from the blood plasma, the proteins would be concentrated along with the platelet cells, further accelerating the natural blood clotting mechanisms and the cross linking of the principal protein found in blood, albumin. In vitro methods with fresh porcine blood would be utilized to demonstrate the efficacy of the candidate materials. The broader outcome of this effort will be a new approach to the combination and fabrication of materials that will robustly staunch the flow of blood in a traumatic wound and lead to a new generation of hemostatic wound dressings. It would also provide cross training of junior researchers in blood physiology and polymer science, to develop their understanding of the essential interdisciplinary and complementary nature of both research fields for the development of advanced bioengineering materials for the 21st century.

This SBIR project brings together the skills and resources of laboratories at Loma Linda University, North Carolina State University, and Scion Cardio-Vascular Inc. (Scion C-V) to advance cytokine treatment for superficial bladder cancer by overcoming significant barriers for achieving paracrine delivery to target cells. This treatment delivers the cytokine interleukin 12 (IL-12) to the bladder wall using Scion C-V������������������s mucoadherent, depyrogenated chitosan (Ch) hydrogel (Ch+IL-12) as the excipient vehicle. Therapeutic effectiveness of the depyrogenated Ch+IL-12 hydrogel will be studied in a relevant mouse bladder cancer model, replicating the pre-clinical studies performed at the National Cancer Institute (NCI). The NCI studies showed remarkable cures of bladder cancer in a mouse model treated with intravesicular Ch+IL-12. The NCI was preparing to test treatment of superficial bladder cancer with Ch+IL-12 in a controlled clinical trial but cancelled the study because of widespread pyrogen contamination in commercially available ����������������medical grade��������������� chitosans. Pyrogen contamination is a well recognized problem that limits the applicability of chitosan as an excipient for implantable biomedical applications. There is an urgent need to define versatile alternative, non-viral methods that reduce the systemic toxicity of chitosan and IL-12 to improve bladder cancer immunotherapy.

The emergence of new infectious diseases and the resurgence of diseases previously controlled by vaccination and treatment are creating unprecedented public health challenges, constituting a significant threat to both global health and national security. The movement of people and goods around the world has increased the opportunity for a local outbreak to become a world-wide pandemic before the causative agent(s) can even be identified. Recent disease outbreaks of Sudden Acute Respiratory Syndrome (SARS), multidrug-resistant tuberculosis, Ebola viral hemorrhagic fever, West Nile viral encephalitis, intentional anthrax, and H5N1 viral infections in humans have heightened concerns about global health security.1 Significant resources have been invested in biosecurity, biosurveillance and medical countermeasures to negate these threats. A variety of different methods are available for collection of biological specimens including blood, urine, sputum, nasopharyngeal (NP) washes, NP aspirates, NP swabs, etc. The use of NP swabs for specimen collection has been an important advance in testing for infectious diseases3, due to ease of use, low material costs and yield of specimens of good quality for detection of pathogens by nucleic acid amplification tests. Swabs can be stored either dry or in media or agar for transportation, however, optimal results samples require cold transport on wet ice and cold storage, refrigeration (2 to 8°C) or freezing (-80°C) if testing is delayed. Current transport mediums (Amies or Stuart media, etc.) are microbe specific (i.e. bacterial or virus), and also have temperature requirements that call for cold-chain transport, a temperature controlled supply chain that must be analyzed, measured, controlled, documented and validated. The most detrimental factors effecting biological sample integrity are likely to occur during transport. With the increased frequency of transport delays due to cost containment measures, consolidations, and services being shifted to centralized or reference laboratories, the ability to preserve sample integrity has become increasingly difficult. To preserve sample integrity throughout the entire collection, transport, and storage process there is a need for a collection material with a corresponding preservation matrix that would increase viral and bacterial viability without temperature control requirements. The collection material would also have a large surface area for maximum recovery capacity and complete controlled release of all biological within the system for maximum analyte recovery, while still retaining compatibility with downstream analyses. To meet this need, Luna Innovations Incorporated proposes to develop a biological specimen collection and transport system that utilizes the stabilizing characteristics of a silica-based encapsulation technology in combination with a unique 3-D nanofiber swab composed of degradable biopolymer to preserve specimen integrity (e.g. viability) while also enhancing analyte recovery. The Phase I program will focus on adapting Luna’s saccharide-modified silica matrices (SBIR Phase II, “Encapsulated Cell Microfluidic Sensor for Water Toxicant Detection” Contract W81XWH-11-C-0023) for maximum viability of a variety of pathogens (bacteria and viruses) at temperatures above -20°C. Luna will team with Dr. Sam Hudson, College of Textiles at North Carolina State University (NC State) to develop the degradable nanofiber biopolymer, maximize analyte recovery and ensure ease of compatibility with down-stream processing. The proposed system of biospecimen collection on a degradable nanofiber swab followed by encapsulation in a saccharide-modified silicate stabilizing matrix will provide significant improvements in storage stability and quantitative recovery of biological analytes (pathogens) as compared to current sample collection technologies, increasing detection capabilities and eliminating the need for cold-chain transport.

Our goal is to develop a resorbable, chitosan-based sealant/hemostat to facilitate the performance of laparoscopic partial nephrectomies (LPN). LPN, a nephron sparing endourologic procedure, can be complicated by bleeding, urine leakage, and prolonged kidney warm ischemia time (1). This procedure remains one of the most underutilized laparoscopic procedures due to the technical complexity of achieving and maintaining hemostasis. A safe, chitosan-based sealant/hemostat with advantages over currently available agents will fill an important clinical need. Specific Aim 1. To depyrogenate our proprietary topical microfibrillar chitosan hemostat by a novel, non-thermal nitrogen plasma technology to enable FDA approval for implantation.* Specific Aim 2. To establish the safety and efficacy of our implanted hemostat using the porcine LPN survival model. These phase I feasibility studies demonstrating that ?this new chitosan product is safe and effective? will be followed by a Phase II SBIR application. The Phase II study will compare safety, effectiveness and cost of our new product to other FDA-approved resorbable hemostats for LPN.

The globalization of disease (2009 H1N1, 2003 SARS) and continued threat of biological weapons have significantly increased world-wide focus on infectious diseases giving them a prime position on the international agenda. The most important step in preventing the spread of infectious disease is rapid and accurate pathogen detection. Currently, etiological agent identification in biological samples is carried out by physicians, laboratories and epidemiologists utilizing a variety of microbial culture and molecular diagnostic techniques. These detection methods commonly utilize swab-like sample collection methods considered cost effective, convenient and do not require trained personnel for sample collection. While technological advances (e.g. immunoassays, molecular diagnostics, and serology) have significantly increased the ability to accurately identify and quantify pathogens in biological samples, and accurate detection requires quality samples. Biological sample quality is completely dependent on proper collection, transport, and storage. The most detrimental factors effecting biological sample integrity are likely to occur during transport. With the increased frequency of transport delays due to cost containment measures, consolidations, and services being shifted to centralized or reference laboratories the ability to preserve sample integrity during transport has become a major factor in ensuring sample integrity. Current preservation methods utilize the addition of transport media (Amies or Stuart media, etc.) or agar for retention of pathogen viability. However, these transport mediums are specific to microbe type (i.e. bacterial or virus) and many still have cold temperature requirements, and at this time no universal transport media exists with the capability of retaining viability of mixed pathogen samples of undetermined etiological origin. The ideal transport medium would: maintain viral and bacterial viability without temperature control requirements, deter bacterial overgrowth, prevent sample drying, allow maximum analyte recovery, and be compatible with downstream analyses. In order to meet this need Luna Inc., teaming with Dr. Sam Hudson, College of Textiles at North Carolina State University (NC State), is proposing to leverage silica-based encapsulation technology in combination with degradable/dissolvable biopolymer nanofibers in order to create a novel material for biological specimen collection and preservation. In the Phase I program, Luna Innovations will leverage technology utilizing saccharide-modified silica matrices in order to develop materials for enhanced preservation of biological samples. Dr. Hudson at NC State will synthesize easily degradable nanofibrous swab materials for rapid dissolution of the collection/preservation matrix, increasing analyte recovery and compatibility with downstream analysis. The proposed technology will provide significant improvements in storage stability, and quantitative recovery of biological pathogens, increasing detection capabilities and eliminating the need for cold chain transport. The ability of a sol-gel matrix to decrease metabolic activity without compromising cell viability will minimize possible organism overgrowth while still retaining maximum viability for detection/analysis.

This proposal addresses the need for conducting fundamental research to develop and evaluate highly absorbable inexpensive chitosan/cellulose based structures with high surface area using electrospun nanofibers. Our team?s main goal is to form and evaluate composite structures for wound dressings. The structures consist mainly of two components. The first is cellulose based hydrogelled materials capable of absorbing at least 10 times of its weight of wound discharge liquids. The hydrogel fibrous structures will be formed by grafting with a vinyl monomer to impart hydrophilic functional groups. The second is a nonwoven layer of nanofibers formed by electrospinning the nanofibers from chitosan/cellulose solutions. We will form a range of extremely thin nonwovens from chitosan/cellulose nanofibers using different blend ratios, electric fields, solution concentrations, and process speeds and study the impact of these on the formed structures (fiber diameter and orientation, surface area, and pore size). The combined fibrous structures of hyrogelled and nanofibers nonwoven will be evaluated for healing performance. Contact kill performance of the structures against range of bacteria and yeast in static test (AATCC Method 100) and dynamic mode (ASTM E-2149-01) will be evaluated. The percent reduction of bacteria (number killed as a percent of total number) as a function of time will be monitored (Modified ASTM E-2149-01). These tests assess healing performance/time of the developed fibrous structures. The healing performance will be correlated to the structural parameters of the nanofibers and the hydrogilled layers a matter that leads to design wound dressings to meet specific needs.

The objective of this research is to develop novel bi-component nanofiber structures that could be used as scaffolds for engineering soft tissues. The approach proposed involves co-axial electrospinning of two different polymers, both biodegradable but one of natural and the other of synthetic origin, to produce ?sheath-core? structure. The natural polymer will form the sheath and is expected to aid in cell adhesion and proliferation while the synthetic polymer will form the core and impart strength and elasticity. Both polymers are biodegradable but one in the sheath, after initiating cell growth and proliferation, will biodegrade first. This will expose the core, which will allow the tissue to continue to grow longer before it itself biodegrades and leaves the tissue ready for implantation. The effects of the processing variables on the relative distribution of the sheath and the core in terms of the diameter of the core, the thickness of the sheath, and the overall diameter of bi-component fibers will be investigated as will be the effects of the material variables on the in vitro degradation rate of sheath and core with respect to their dimensions. Also, the mechanical properties of the resulting hybrid nonwoven webs will be determined. In a parallel effort an effective sterilization method will be identified which will not adversely affect the mechanical integrity of the scaffolds. In the final phase of the project actual cell-culture studies will be performed to evaluate the viability of these textile-based structures for engineering of soft tissues for clinical applications.

This proposal focuses solely on Phase 1 of a three phase project to develop a revolutionary healthcare garment that could supersede the inadequate attire patients are currently expected to wear when receiving healthcare services. The key objectives of Phase 1 are to provide a comprehensive description of the requirements for well-designed, comfortable and functional healthcare garments, and of the market opportunity for such garments. Requirements of all customers in the supply network including the patients, healthcare providers, manufacturers and distributors of gowns, hospital purchasing officers, members of central surgical supply teams, family caregivers and other stakeholders will be considered in the research. Data will be gathered through site visits to healthcare facilities and through teleconferencing to ensure a broad and representative sample. Qualitative data collection techniques employed may include observation, personal interviews, telephone interviews and teleconferences, and focus groups either in person or via teleconference. Through these, the researchers will gather information about key issues, and delineate specific product requirements and market concerns. Surveys may be employed to acquire quantitative data on the importance of product requirements to each customer group, and the scope of potential markets. Successful completion of Phase 1 will result in a comprehensive set of customer requirements for healthcare garments useful to hospitals, home care suppliers, hospices, nursing homes, extended care facilities, and related industries. It will also provide a market analysis useful to suppliers considering participation in Phases 2 and 3. Results will be shared through conferences, publication of research results, and by engaging stakeholders including producers, distributors, and auxiliary businesses in the work. Our research team is uniquely qualified to undertake this work. Though there is some risk that we will encounter challenges in gathering the data within the proposed timeline, we are minimizing this risk by partnering with WakeMed Health and Hospitals.

Chitin, found in the shells of crabs, lobsters, shrimp and other crustaceans, as well as insect exoskeletons and cell walls of some fungi, is considered the second most abundant natural resource on earth next to cellulose. Each year in the United States, thousands of tons of chitin are produced as processing wastes of the crabbing and shrimp industry. Chitosan, derived from the acetylation of chitin, is a versatile polymer that can be converted into films, fibers, coatings, gels, beads, pastes, solutions and powders. Chitosan has been shown to have anti-microbial activity against bacteria, viruses and fungi, and has been reported to induce the expression of a variety of genes involved in plant defense. In addition to its mode of action as an elicitor of plant host defense responses, chitosan possesses unique chemical properties that may further contribute to its effectiveness as a potential bio-pesticide. The focus of this project will be on these unique physical properties of chitosan and modifications that can be made to its structure that will capitalize on its anti-microbial activity. The mechanism for growth inhibition by chitosan is distinctly different from that of currently used synthetic pesticides. This is of importance due to the widespread occurrence of pesticide resistance. Because chitosan functions by inducing the expression of host defense genes and by physical exclusion of the pathogen, resistance to chitosan would be highly unlikely. The overall objective of this research is to utilize a natural waste product for direct application in managing plant health. This will require designing and developing chemical derivatives of chitosan that exhibit a high degree of anti-microbial activity. The identification of such derivatives could ultimately lead to the commercial development of a new bio-pesticide.

3TEX will supply Carbon Nanotube Fiber from which NCSU will form single yarn composites. NCSU will analyze mechanical properties and return samples to 3TEX.