Structural Analysis of Human Tissue

Background The skin is a large organ that participates in many protective and homeostatic
processes. The functions of the skin can be roughly divided into systemic and local ; both
are interrelated but relationships are poorly understood and studying them requires a
multiscale approach. Particularly, for the local responses that are mediated by activation of
proteolytic and signaling pathways such as coagulation and inflammation, the relevant scale
corresponds to the micrometer and nanometer dimensions of cells and macromolecules,
respectively. There is very little information on the physicochemical characteristics of the
skin at these scales.

Objective The investigators propose to analyze fresh human skin samples using several
up-to-date technologies to obtain parameters on the mechanical, biochemical and structural
distribution of the main components of the capillary-tissue unit.

Hypothesis/Rationale Our working hypothesis is that both structural components of the dermis,
such as glycosaminoglycans, and key mediators of homeostatic pathways, such as the
procoagulant tissue factor are not evenly distributed along parallel planes. The
investigators further hypothesize that the distribution patterns determine functional and
mechanical differences along dermal layers.

Methods Using a dermatome, human skin will be dissected along planes parallel to the
epidermis into several layers each approximately .0012mm thick. The layers will be analyzed
with respect to composition of diffusible proteins and glycosaminoglycans; subjected to high
resolution MRI and AFM scanning; and evaluated for swelling rate and equilibrium swelling
pressure.

Significance This study will provide new information on material characteristics and
functional structure of the human skin at resolutions relevant to the macromolecular and
cellular processes that mediate local responses to injury and maintain local homeostatic
mechanisms. The data will be further processed to obtain realistic parameters that are needed
to develop predictive models of the skin capillary tissue unit. These models will bring new
and deeper understanding on skin physiology and pathology and will aid in the discovery and
testing of new preventive and therapeutic approaches targeting dysfunctions of the local
homeostatic balance in the skin. Potentially, by exploiting the versatility of mathematical
simulations in the skin model, the findings will also be applicable to other tissue organs.

Inclusion Criteria:

- Subjects, male or female , between the ages of 18 to 65 years of age, who will be
having surgery to remove excess skin from the abdominal area by surgeons in the
Department of Plastic & Reconstructive Surgery

Exclusion Criteria:

- Subjects younger then 18 years of age or older than 65 years of age, and are not
having excxess skin surgically removed