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Associate Professor This email address is being protected from spambots. You need JavaScript enabled to view it.
Hoehn 370
(205) 934-8426

Research and Teaching Interests: Biomaterials enhanced regeneration, Tissue engineering, Degradable scaffolds and repair devices (metals and polymers predominantly) 

Office Hours: By appointment

Education:

  • B.S., Northwestern University, Biomedical Engineering
  • M.S., University of Dayton, Materials Engineering
  • Ph.D., Clemson University, Bioengineering

I was born in Chicago, IL and stayed there through college at Northwestern University. My major was BME with a concentration in biomaterials. I graduated when BME programs were first being developed; there was not a department at Northwestern, but it had the largest enrollment in the School of Engineering. I was in the marching band there, which I continued throughout graduate school (not many graduate students in college marching bands). I continued my education at University of Dayton; the main research center there was in materials engineering, and included experts in biomaterials (bioglass and ceramics). My research was on crystal growth in gout, which has kept me interested in the biological response to fibers and particles. In gout as well as implants the inflammatory response is greatest when the diameter of the fiber/crystal/particle is close to the size of macrophages (the key cell in the foreign body response). They ultimately convinced me to get my Ph.D. at the school where biomaterials really started: Clemson University.

At Clemson I studied failure modes of percutaneous devices, which is related to the diameter of the dacron fibers I used for the skin-penetrating device. I got married (met her in the marching band), had our first child, and then moved to Texas for my first academic job in Bioengineering at Texas A&M (note: it is important to have a baby right before making a big move). While I was at Texas A&M we had three more children (the last right before moving here — because again it is important to have a baby right before making a big move). I have been at UAB for 31 years; during that time I have been the research advisor for 10 Ph.D. students and 34 M.S. students.

My main research area is biomaterial enhanced regeneration. This includes basic research to enhance wound healing (studies of oxygen, electric and magnetic fields, growth factors, etc.) and to enhance the scaffolding of the biomaterial (studies changing the implant configuration, the implant surface, the implant bioactivity, the implant degradation rate, the implant drug delivery rate, etc.). In doing these studies (especially clinical studies) I realized that there was a need for better quantification techniques of healing. Therefore research has also been aimed at developing better in vivo quantification techniques as well as portable non-invasive assessments of the ability of these systems to enhance healing. This research is conducted using cell culture and animal studies as well as has been applied to tissue regeneration for the following clinical applications pressure ulcers, burns, blood vessels, nerves, bone, cartilage, microvascular anastomosis, and catheter design.

You can learn more about my research in the "Research Interests" section below.

Download Curriculum Vitae (PDF)

  • Recent Courses

    I helped develop and still participate in the two-semester senior design sequence. This is in essence what a BME degree leads up to: giving the student enough content knowledge so they can go through the design process in a BME application as well as understand the steps to commercialize a medical device.

    The other main class I teach is a tissue interaction course, which is for both graduate and undergraduate students. The class has three parts:

    1. Students are exposed to histology and implant pathophysiology so they can understand the histology portion of biomaterials papers and talks.
    2. The course then goes into more depth about the types of biological responses around implants.
    3. Finally, students use the first two parts to help go through the steps necessary to get regulatory approval of a device of the student’s choosing.

  • Research Interests

    Most of what I do relates to restorative/repair phenomenon. My interest is in designing better scaffold systems to help repair and regenerate damaged tissue. Although the main interest is in degradable regenerative systems; it is realized that in many cases you have to start with a system that is not degradable or regenerative and research ways to make it that way (I call this the biocompatibility hierarchy). I have also examined methods to attach tissue and/or immobilize it to help in the healing process (e.g. bone plates, intramedullary rods, and sutures).

    Over the years different matrix materials and strategies have been used. In the last 20 years the main application has been skin wounds. Most recently it has been degradable metals for orthopedics. For skin wounds, the most recent efforts have been in developing a treatment for pressure ulcers in an injured spinal cord that could be delivered at the patient’s home by a home-health nurse.  The goal is not only to shorten the healing time, but to do so in a cost-effective, commercializable way. This is similar to part of the design requirements for our students in senior design projects. Although I have explored tissue engineering methods to get the maximum healing benefit; — with stem cells, growth factors, and gene therapy — the ultimate solution needs to be as simple as possible with a reasonable path through the FDA and lead to a reduction in health care costs (typically by moving care to less expensive settings and provided by individuals who charge less for their services — also reducing post treatment care time and therefore costs).

    One of the solutions has been an electric bandage that mimics the field in regenerative animals vs. the scarring in humans. This came out of a M.S. project and turned into a company (with my former student as president) that developed a product that is being sold overseas (recently bought by L’Oreal). The other approach has been using a natural tissue adhesive scaffold to mimic the structure, function, and mechanical properties of the normal provisional wound healing matrix; degrading and releasing factors and chemoattractants as the wound heals under biofeedback control. In addition, we have been adding the patient’s own stem cells (endothelial progenitor cells or mesenchymal stem cells). The system works as a two part glue that sets up in and conforms to the wound as well as can be administered at the patient’s home.

    I have also been working on commercializing degradable metals for orthopedic applications. This came from collaborators at the University of Alabama who have developed a surface treatment that can slow the degradation of Mg-based metals, in a controllable way, in order to make them useful for orthopedic applications. We have just finished a Phase I STTR showing in vitro feasibility and are currently working on Phase II proposals that will select specific applications (some that senior design students have worked on). The initial focus will be on internal fixation devices.

  • Select Publications
    • Sealy, M., Guo, Y., Caslaru, R., Sharkins, J., and Feldman, D., Fatigue performance of biodegradable magnesium–calcium alloy processed by laser shock peening for orthopedic implants, Int J Fatigue, 82:428-436, 2016 (online September 2015).
    • Stoff A, Rivera AA, Sanjib Banerjee N, Moore ST, Michael Numnum T, Espinosa-de-Los-Monteros A, Richter DF, Siegal GP, Chow LT, Feldman D, Vasconez LO, Michael Mathis J, Stoff-Khalili MA, Curiel DT, Promotion of incisional wound repair by human mesenchymal stem cell transplantation. Exp Dermatol. 2009 Apr;1 8(4):362-9.
    • Jennings, A., Chen, D., and Feldman, D., Transcriptional response of dermal fibroblasts in direct current electric fields, Bioelectromagnetics, 29(5): 394-405, 2008.
    • McClain, A. and Feldman, D., Engineering applications for middle school mathematics education: supporting an inquiry-based classroom environment, American Society for Engineering Education, 2007.
    • Kilpadi, D. and Feldman, D., Biocompatibility of silicone gel breast Implants, Biomaterials Engineering and Devices: Human Applications, Vol. 1, ed. D. Wise, 2000, Humana Press, Totowa, NJ, 57-84.
    • Bowman, J. and Feldman, D., Tissue adhesives for growth factor delivery, Biomaterials and Bioengineering Handbook, ed. D. Wise, 2000, Marcel Dekker, New York, 261-312.
    • Feldman, D., Barker, T., Blum B., Kilpadi, D., and Redden, R., Tissue assessment of skin substitutes, Biomaterials and Bioengineering Handbook, ed. D. Wise, 2000, Marcel Dekker, New York, 773-806.
    • Feldman, D., Barker, T., Bowman, J., Blum B., Kilpadi, D., and Redden, R., Biomaterial enhanced regeneration for skin wounds, Biomaterials and Bioengineering Handbook, ed. D. Wise, 2000, Marcel Dekker, New York,  807-842.
    • Saltz, R., Sierra, D., Feldman, D., Saltz, M., Dimick, A., and Vasconez, L., Experimental and clinical applications of fibrin glue, Plastic and Reconstructive Surgery, 88(6): 1005-1015, 1991.
  • Academic Distinctions and Professional Societies
    • Adjunct appointment at UAH and the University of Alabama
    • Secondary faculty appointment in Materials Engineering at UAB
    • Society for Biomaterials
    • Wound Healing Society
    • Biomedical Engineering Society
  • Student Groups
    • Faculty advisor for BMES
    • Faculty advisor for SFB