Visualization of morphological and molecular features associated with chronic ischemia in bioengineered human skin

Use of voltammetric analysis for fast and objective discrimination of the etiology, evolution, and bacterial infection of lower limb ulcers

The timely recognition of leg ulcers (LU) etiology and infection is pivotal to optimize management and accelerate healing. The objective of this proof-of-concept study was to test the diagnostic performance of voltammetric analysis (VA) on ulcer exudate to identify LU etiology, infection, and predict clinical course. We enrolled 25 patients aged ≥60 years, affected by 42 venous/arterial LU. Clinical examination (Leg Ulcer Measurement Tool score, LUMT), swab culture, and VA were performed at baseline and 30 days. The ability of VA to predict outcomes was tested using partial least square-discrimination analysis. Mean age was 75 years (SD 11.1), 9/25 were male. The accuracy, sensitivity, and specificity vs. etiology were 97.4, 100%, and 94.1%, respectively; the corresponding figures were 95.2%, 100%, 88.9%, for infection and 94%, 84.6%, 100% for predicted objective LUMT worsening. VA is a promising diagnostic/prognostic tool for management of LU that may allow a more timely targeted therapy.

Hypoxia preconditioning of tissue-engineered mucosa enhances its angiogenic capacity in vitro

Improving vascularization of tissue-engineered oral mucosa (TEM) is a major challenge in the field of plastic surgery. Hypoxia is a stimulator of angiogenesis through a number of mechanisms. Therefore, hypoxia is a critical parameter that can be controlled in an effort to improve angiogenesis. In the present study we studied the secretion of a number of angiogenic factors during hypoxia exposure and evaluated the effect of TEM conditioned medium on endothelial cells. TEM was constructed by seeding human oral mucosa keratinocytes and fibroblasts on acellular human donor skin. TEM was exposed to hypoxia during 6, 12, and 24 h. Cellular hypoxia was assessed by immunolocalization of the hypoxia-inducible factor-1α. Secretion of vascular endothelial growth factor, placental growth factor (PlGF), tissue inhibitors of matrix metalloproteinases-1 and -2, and the activity of matrix metalloproteinase-9 significantly increased during hypoxia exposure. Moreover, conditioned medium from hypoxic TEM strongly enhanced endothelial cell proliferation and migration. In vitro exposure of TEM to hypoxia improves its capacity to support endothelial cell proliferation and migration, which suggests that hypoxia preconditioning of TEM potentially improves angiogenic responses for in vivo implantation.