Pilot study to evaluate a novel three-dimensional wound measurement device.

As the burden of diabetes continues to grow and treatment standards require careful tracking of wound progress, clinicians increasingly need to rely on technological improvements in wound measurement technologies to track the progress of their treatments. This study aims to determine the accuracy of a new three-dimensional wound measurement (3DWM) device against laser-assisted wound measurement (LAWM) devices and traditional methods of wound measurement. Using several wound models, we demonstrate that the 3DWM device measures wound area, depth and volume similarly to the other methods tested. This is especially apparent when changes in wound measurements were compared between the two devices. Differences between the two technologies were apparent when analysing wound measurement time and measurement repeatability. There was a significantly lower incidence of error in measurements between the 3DWM device and the LAWM device. Finally, the measurement time was significantly faster with the 3DWM device compared to the LAWM device. Together, these data demonstrate that the 3DWM device provides an accurate and reproducible method for measuring changes in wound healing similar to other available technologies. Further, the use of the 3DWM device provides a faster and more consistent measurement, which is critical for clinical application and use.

Ultraviolet-A Light and Negative-Pressure Wound Therapy to Accelerate Wound Healing and Reduce Bacterial Proliferation.

BACKGROUND: Ultraviolet (UV)-A therapy is a simple, inexpensive, and effective modality for wound healing, with tremendous potential to improve healing and reduce clinical infections in a number of clinical settings. To date, application of UV-A relies on bulky and hard-to-dose lamps that provide inconsistent therapy, thus making it difficult to apply therapy that is appropriate for the patient. METHODS: This study was designed to test the effectiveness of a novel wound therapy device that combines UV-A with traditional negative-pressure wound therapy (NPWT) to promote wound healing. Furthermore, we tested the ability of fiberoptic UV-A delivery to inhibit bacterial proliferation. Finally, we assayed the level of DNA damage that results from UV-A as compared to established UV-C therapies. Wound healing studies were performed in a porcine model using an articulated therapy arm that allows for continued therapy administration over an extended time course. Negative-pressure wound therapy was administered alone or with UV-A fiberoptic therapy for 2 weeks. Dressings were changed twice a week, at which time wound area was assessed. RESULTS: Data demonstrate that UV-A with NPWT treatment of wounds results in greater healing than NPWT alone. Using the same therapy device, we demonstrate that exposure of Staphylococcus aureus and Pseudomonas aeruginosa to fiberoptic UV-A results in decreased colony area and number of both bacterial strains. Finally, we show that UV-A induces minimal DNA damage in human fibroblasts and no more DNA damage in wound tissue as compare to intact skin. CONCLUSIONS: These data demonstrate that UV-A can decrease bacterial proliferation and promote wound healing when coupled with NPWT.

Hemodynamics, electrolytes, and organ histology of larger-volume liposuction in a porcine model.

Liposuction is a procedure that allows the surgical removal of excess adipose tissue in healthy individuals. Lipoplasty is commonly performed with few clinical side effects. However, with increased lipoaspirate volumes, complications have been reported. In addition, the abnormal appearance of fat cells in other tissues subsequent to lipoplasty has been reported in a small number of cases. The authors examined whether larger-volume lipoplasty, in the porcine model, resulted in disturbances in cardiac or pulmonary output levels, electrolytes, and liver chemistry analyses or alterations in organ histology. Nine adult porcine specimens were subjected to either lipoplasty (n = 6) with the superwet technique or no lipoplasty (n = 3). Using a Swan-Ganz catheter, cardiac output and pulmonary artery pressure measurements were obtained from initial placement before lipoplasty until 48 hours postoperatively. Blood analyte measurements were obtained. Upon euthanization, liver, kidney, and lung specimens were collected and tissue sections were prepared. No significant differences or trends were observed in cardiac parameters or blood analytes between control and experimental groups. Significant elevations in serum aspartate aminotransferase and alanine aminotransferase enzyme levels (p < 0.03) were observed in animals postoperatively (10 to 48 hours) subjected to lipoplasty compared with controls. Upon gross examination, the lung tissues of animals subjected to lipoplasty unexpectedly demonstrated patchy petechial hemorrhages on the pleural surface. Tissue sections revealed marked hemorrhagic congestion and evidence of pulmonary edema. Fat emboli were also identified within the pulmonary and renal systems.

Genome editing of mouse fibroblasts by homologous recombination for sustained secretion of PDGF-B and augmentation of wound healing.

BACKGROUND: Exogenous cytokines, such as platelet-derived growth factor (PDGF)-B, can augment wound healing, but sustained delivery to maintain therapeutic levels remains a problem. "Genome editing" is a new technology in which precise genome modifications are made within cells using engineered site-specific nucleases. Genome editing avoids many of the complications associated with traditional gene therapy and the use of viral vectors, including random integration, imprecise gene expression, and inadvertent oncogene activation. METHODS: This study demonstrates site-specific nuclease-mediated integration of a PDGF-B transgene into a predefined locus within the genome of primary mouse fibroblasts. Engineered fibroblasts were applied to splinted mouse wounds and evaluated after 14 days and 5 months for the retention of engineered fibroblasts, wound healing morphology, angiogenesis, and systemic PDGF-B expression. RESULTS: The application of engineered PDGF-B-expressing fibroblasts enhanced wound healing compared with controls. Low-level, constitutive expression of PDGF-B was achieved without detectable levels of systemic PDGF-B. The mechanism of improved wound healing is, at least in part, the result of increased wound vascularization, as the wounds treated with PDGF-B fibroblasts had a blood vessel density 2.5 times greater than controls. After 5 months, the engineered fibroblasts persisted in the wound bed. No adverse effects were detected from the application of these fibroblasts after 5 months as assessed by hematoxylin and eosin staining of wounds and by mouse necropsy. CONCLUSIONS: These data support that site-specific genome editing allows for sustained cell-based cytokine delivery. Furthermore, sustained release of PDGF-B increases the speed and quality of wound healing after a single application.

Validation of a laser-assisted wound measurement device for measuring wound volume.

BACKGROUND: Accurate and precise wound measurement is an essential part of the medical record when monitoring a patient with a chronic wound. This study was designed to determine if a new device, a laser-assisted wound measurement (LAWM) device, provides valid measurements for wound area, depth, and volume. METHODS: We compared four methods to evaluate the area and volume of 12 wounds of differing size and depth that were created on the dorsum of a sacrificed pig. We evaluated the LAWM device, digital photograph assessment with National Institutes of Health ImageJ software, measurements of depth with a ruler, and weight-to-volume assessment with dental paste. We then sought to cross validate this data with further analyses obtained from these measurements using a Play-Doh®-based wound as a model for constant area with different depths. RESULTS: We demonstrate that the LAWM device measures wound area accurately. Depth (and therefore volume) measurements, however, are artificially low. This inaccuracy is the same for shallow and deep wounds. CONCLUSIONS: The inaccuracy in the depth and volume measurements with the LAWM device results in an artificially low measurement. However, this may not affect percentage difference measurements. Further studies will need to be performed to determine if this device can accurately determine wound changes in the clinical setting.