Lisa J. Gould

Effect of NASA light-emitting diode irradiation on wound healing.

OBJECTIVE The purpose of this study was to assess the effects of hyperbaric oxygen (HBO) and near-infrared light therapy on wound healing. BACKGROUND DATA Light-emitting diodes (LED), originally developed for NASA plant growth experiments in space show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper, we review and present our new data of LED treatment on cells grown in culture, on ischemic and diabetic wounds in rat models, and on acute and chronic wounds in humans. MATERIALS AND METHODS In vitro and in vivo (animal and human) studies utilized a variety of LED wavelength, power intensity, and energy density parameters to begin to identify conditions for each biological tissue that are optimal for biostimulation. RESULTS LED produced in vitro increases of cell growth of 140-200% in mouse-derived fibroblasts, rat-derived osteoblasts, and rat-derived skeletal muscle cells, and increases in growth of 155-171% of normal human epithelial cells. Wound size decreased up to 36% in conjunction with HBO in ischemic rat models. LED produced improvement of greater than 40% in musculoskeletal training injuries in Navy SEAL team members, and decreased wound healing time in crew members aboard a U.S. Naval submarine. LED produced a 47% reduction in pain of children suffering from oral mucositis. CONCLUSION We believe that the use of NASA LED for light therapy alone, and in conjunction with hyperbaric oxygen, will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the NASA Marshall Space Flight Center-SBIR Program.

Guidelines for the treatment of pressure ulcers

1. Co-chaired this panel 2. University of Washington, Seattle, WA 3. University of Texas Medical Branch Galveston, Galveston, TX 4. Sinai Hospital, Baltimore, MD 5. Johns Hopkins Medical Institutions, Baltimore, MD 6. University of Southern Denmark, Odense University Hospital, Odense, Denmark 7. University of South Florida, Tampa, FL 8. University of Virginia Health System, Charlottesville, VA 9. St. Louis Medical Center, St. Louis, MO, and 10. University of San Francisco, San Francisco, CA

Effect of NASA Light-Emitting Diode Irradiation on Molecular Changes for Wound Healing in Diabetic Mice

OBJECTIVE The purpose of this study was to assess the changes in gene expression of near-infrared light therapy in a model of impaired wound healing. BACKGROUND DATA Light-Emitting Diodes (LED), originally developed for NASA plant growth experiments in space, show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper we present the effects of LED treatment on wounds in a genetically diabetic mouse model. MATERIALS AND METHODS Polyvinyl acetal (PVA) sponges were subcutaneously implanted in the dorsum of BKS.Cg-m +/+ Lepr(db) mice. LED treatments were given once daily, and at the sacrifice day, the sponges, incision line and skin over the sponges were harvested and used for RNA extraction. The RNA was subsequently analyzed by cDNA array. RESULTS Our studies have revealed certain tissue regenerating genes that were significantly upregulated upon LED treatment when compared to the untreated sample. Integrins, laminin, gap junction proteins, and kinesin superfamily motor proteins are some of the genes involved during regeneration process. These are some of the genes that were identified upon gene array experiments with RNA isolated from sponges from the wound site in mouse with LED treatment. CONCLUSION We believe that the use of NASA light-emitting diodes (LED) for light therapy will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the Defense Advanced Research Projects Agency (DARPA) and NASA Marshall Space Flight Center-SBIR Program.

Guidelines for the treatment of venous ulcers

1. Co-chaired this panel2. University of South Florida, Tampa, FL3. Healthpoint Ltd., Fort Worth, TX4. University of California, San Francisco, CA5. University of Texas Medical Branch, Galveston, TX6. University of Cardiff, Cardiff, Wales, UK7. University of Pennsylvania, Philadelphia, PA8. Private practice, Warren, PA9. Private practice, Tamarac, FL10. University of Pittsburgh, Pittsburgh, PA11. St. Louis University, St. Louis, MO, and12. Washington University, St. Louis, MO

Proteolytic activity in wound fluids and tissues derived from chronic venous leg ulcers.

Venous leg ulcers affect approximately 1% of the general population and 3.6% of those over the age of 65. The goal of the research described herein is to shorten the time to healing by developing wound care alternatives that are based on a comprehensive understanding of the venous ulcer wound environment. The proteolytic and inflammatory components in wound fluids and tissue biopsy samples were characterized in subjects with documented long‐standing venous ulcers that had showed resistance to standard therapy. All wounds showed polymicrobial colonization with greater than 106 CFU/g. Myeloperoxidase, a measure of leukocyte infiltration, was also markedly elevated in these wounds. Zymography revealed the presence of both pro‐matrix metalloproteinase (MMP)‐2 and pro‐MMP‐9 in wound fluids and to a lesser extent in tissue biopsies. Using an immunocapture activity assay we reveal a sevenfold excess of MMP‐9 in wound fluid as compared to tissue, with 73% in the activated form. In contrast, MMP‐8 total protein levels were nearly equal in wound fluids and biopsies. Fibronectin, a critical component of the extracellular matrix, was shown to be degraded in both wound fluids and biopsy samples. Finally, the potential of a novel wound dressing to neutralize several constituents of this hostile wound environment is shown.

Hyperbaric oxygen attenuates apoptosis and decreases inflammation in an ischemic wound model.

The molecular mechanisms whereby hyperbaric oxygen (HBO) improves ischemic wound healing remain elusive. In this study, a rat model of wound ischemia was used to test the hypothesis that HBO enhances wound healing by modulating hypoxia-inducible factor-1alpha (HIF-1alpha) signaling. Male Sprague-Dawley rats underwent creation of a previously validated ischemic flap. Three groups underwent daily treatment: HBO (90 minutes, 2.4 atm); systemic administration of the free radical scavenger, N-acetylcysteine (NAC 150 mg kg(-1) intraperitoneal); control (neither HBO nor NAC). HBO treatment improved healing of the ischemic wounds. Analysis of ischemic wound tissue extracts demonstrated significantly reduced expression of HIF-1alpha, p53, and BNip3. Additionally, HBO increased expression of Bcl-2 while decreasing cleaved caspase-3. DNA fragmentation was abolished and the number of TUNEL-positive cells was reduced compared to the other groups. Vascular endothelial growth factor, cyclooxygenase-2, and neutrophil infiltration were reduced in ischemic wounds treated with HBO. These results indicate that HBO improves ischemic wound healing by downregulation of HIF-1alpha and subsequent target gene expression with attenuation of cell apoptosis and reduction of inflammation.

Guidelines for the prevention of pressure ulcers

The Wound Healing Society is a professional organization of physicians, nurses, physical therapists, basic scientists, clinical researchers, and industrial researchers dedicated to assuring that every patient receives optimal wound care. Its mission is to advance the science and practice of wound healing. To that end, the following comprehensive, evidence- and consensus-based guidelines were developed to address the Prevention of Pressure Ulcers. The guidelines are presented in generic terms; the details of specific tests, therapies, and procedures are the discretion of an interdisciplinary team of health care professionals who establish, implement, and evaluate policies and procedures directed at the prevention of pressure ulcers.

Characterization of a preclinical model of chronic ischemic wound

Chronic ischemic wounds presenting at wound clinics are heterogeneous with respect to etiology, age of the wound, and other factors complicating wound healing. In addition, there are ethical challenges associated with collecting repeated biopsies from a patient to develop an understanding of the temporal dynamics of the mechanisms underlying chronic wounds. The need for a preclinical model of ischemic wound is therefore compelling. The porcine model is widely accepted as an excellent preclinical model for human wounds. A full-thickness bipedicle flap approach was adopted to cause skin ischemia. Closure of excisional wounds placed on ischemic tissue was severely impaired resulting in chronic wounds. Histologically, ischemic wounds suffered from impaired re-epithelialization, delayed macrophage recruitment and poorer endothelial cell abundance and organization. Compared with the pair-matched nonischemic wound, unique aspects of the ischemic wound biology were examined on days 3, 7, 14, and 28 by systematic screening of the wound tissue transcriptome using high-density porcine GeneChips. Ischemia markedly potentiated the expression of arginase-1, a cytosolic enzyme that metabolizes the precursor of nitric oxide l-arginine. Ischemia also induced the SOD2 in the wound tissue perhaps as survival response of the challenged tissue. Human chronic wounds also demonstrated elevated expression of SOD2 and arginase-1. This study provides a thorough database that may serve as a valuable reference tool to develop novel hypotheses aiming to elucidate the biology of ischemic chronic wounds in a preclinical setting.

Optimization and validation of an ischemic wound model

Localized tissue ischemia is a key factor in the development and poor prognosis of chronic wounds. Currently, there are no standardized animal models that provide sufficient tissue to evaluate the effect of modalities that may induce angiogenesis, and in vitro models of angiogenesis do not mimic the complexity of the ischemic wound bed. Therefore, we set out to develop a reproducible ischemic model for use in wound‐healing studies. Male Sprague–Dawley rats underwent creation of dorsal bipedicle skin flaps with centrally located excisional wounds. Oxygen tension, wound‐breaking strength, wound area, lactate, and wound vascular endothelial growth factor (VEGF) were compared in flaps measuring 2.5 and 2.0 × 11 cm with and without an underlying silicone sheet. We found that the center of the 2.0 cm flap with silicone remains in the critically ischemic range up to 14 days without tissue necrosis (33±4 vs. 49±6 mmHg in controls). Wound healing and breaking strength were significantly impaired and tissue lactate from the center of this flap was 2.9 times greater than tissue from either nonischemic controls and 2.5 cm flap (0.23±0.05 mg/dL/mg sample vs. 0.09±0.02 and 0.08±0.02, respectively). Vascular endothelial growth factor was 2 times greater than the nonischemic control. This ischemic wound model is relatively inexpensive, easy to perform, reproducible, and reliable. The excisional wounds provide sufficient tissue for biochemical and histologic analysis, and are amenable to the evaluation of topical and systemic therapies that may induce angiogenesis or improve wound healing.

Study of the neural and vascular anatomy of the anterolateral thigh flap

UNLABELLED The purpose of this study was to perform a detailed investigation of the vascular and neural structures of the anterolateral thigh (ALT) flap, with emphasis on the peripheral neurovascular system of the subcutaneous adipofascial layer. METHODS Ten cadavers were examined after injection of latex into the bilateral external iliac arterial system. The nutrient vessels of the femoral cutaneous nerves and the relationship between these vessels and the adjacent tissue were studied. RESULTS The intrinsic and extrinsic neurocutaneous vascular systems surrounding the cutaneous nerves in the deep adipofascial layer were explored. The extrinsic neurocutaneous vascular system consisted of chain-like anastomoses formed by segmental arteries derived from perforators and revealed a distinct axial course along the nerves. The first segmental artery of the extrinsic neurocutaneous system was found to be the longest and to have the greatest diameter. The three-dimensional vascular structure of the ALT flap resembled a tree, in that the nutrient vessels arborised in each layer with their length and diameter decreasing from the deep adipofascial layer to the superficial adipofascial layer. Two categories of branch vessels connect the suprafascial plexus and subdermal plexus in the ALT flap: (1) large branches derived directly from the perforator ascend obliquely or vertically to the skin and (2) small branches arise from the nerves nutrient artery and ascend to the skin. CONCLUSIONS The ALT flap is ideal for soft-tissue reconstruction in the Asian population. Preservation of the large branch vessels ensures flap survival during primary defatting, allowing for improved contour in single-stage reconstructions. It is also possible to design a proximally pedicled neurocutaneous flap based on the cutaneous nerve in the thigh and its corresponding vascular system. This neurocutaneous flap may offer a novel advantage for sensate reconstruction of the perineum.