Date of Award


Degree Type


Degree Name

Master of Science in Biomedical Sciences

First Advisor

Charlotte Greene, PhD

Second Advisor

Marcus Bell, PhD

Third Advisor

David Cavanaugh, BS


Introduction The goal of this study was to determine if the repair of full thickness skin incisions in an animal model could be improved by using a CO2 laser vs. scalpel, commercial vs. swine intestinal submucosa (SIS) sutures, and addition of exogenous nerve growth factor (NGF).

Materials and Methods A rat model was used to evaluate the following tissue components: prevalence of mast cell granules, thickness of epidermis, organization of collagen, infiltration of tissue into SIS, neutrophil presence around suture holes, and granulation tissue production around suture holes.

Results Added NGF led to a significant decrease in the number of granules in mast cells following laser incisions. A significant number of neutrophils were detected in skin following laser incision without added NGF. Added NGF significantly increased the band iv of granulation tissue for both types of incision methods however, the laser resulted in a significantly wider band of granulation tissue with or without added NGF. A thicker epithelium was apparent following use of laser as was the level of collagen organization. Added NGF significantly increased incorporation of skin elements into SIS sutures. The use of the laser without NGF resulted in greatest collagen organization, number of mast cell granules, and neutrophils, and significantly greater vascularization.

Discussion The greater extent and duration of granulation tissue proliferation following laser incision may be attributable to an inappropriately high laser dosage. Collagen organization improves with laser use. Incorporation of tissue into SIS sutures was promoted by adding NGF, but unaffected by surgical technique. Increased vascularity following laser incision suggested blood vessels re-opened or angiogenesis occurred post-surgery. With added NGF, epidermal width following laser incision was even greater in contrast to the scalpel incised group. Depending upon the intent of the surgeon, the use of surgical modality, suture material, or additional exogenous NGFs has to be tailored to the specific patient and desired outcome