Collagen Fibers & Wounds
 

A wound is a break in the tissues of the body. Some injuries, like cuts and scrapes, are called open wounds; others, like deep bruises, are called closed wounds. They are usually caused by external forces such as motor vehicle accidents, falls, burns, and the mishandling of sharp objects, tools, machinery, and weapons. 

    
The intended use of the Laser Doppler Perfusion imager is two-dimensional mapping of peripheral blood perfusion (circulation) and  for visualization of two-dimensional microvascular flow-maps in a number of clinical settings including investigations of peripheral vascular disease, skin irritants, diabetics, burns, and organ transplants.

Laser 
Doppler 
Perfusion 
images

  LISCA - Laser Perfusion Imaging of Wounds     LISCA - Laser Perfusion Wound Imaging
    

      Up to 5,000,000 wounds, many chronic, occur every year in the U.S.  When skin is injured, the natural "weave-like" structure of the collagen fibers is destroyed.  Collagen is the major structural protein of skin and is responsible for its tensile strength, elasticity, and pliability. It is synthesized in the dermis by FIBROBLASTS. 
     

     Fibroblasts produce tropocollagen, which is the forerunner of collagen, and ground substance, an amorphous, gel-like matrix that fills the spaces between cells and fibers in connective tissue.
     Scarring is caused by excess production of collagen during healing.
To minimize blood loss and infection the body initiates a rapid heal: FIBROBLASTS [EM] produce and begin laying down thin, linear strips of replacement collagen.  As new skin cells grow on the replacement collagen fibers, they manufacture a pale, less flexible material that eventually forms scar tissue.


Some current research solutions to helping wound repairing:   [skin cell culture]
 

1.  cultured human dermal tissue  -  Artificial Skin...[Apligraft / Dermagraft] a bioengineered product that contains cultured (lab-grown) human dermal material (including the foreskin of circumsized infants), proteins, and growth factors. Applied to the wound, this material proliferates, generating new human dermal tissue.  Dermagraft foreskin can be grown on layered matrix substrates (polymer fibers) making skin grafts that secrete growth factors.

2.  ELECTROSOLS - Oxford Biotech Company
          a spray-on dressing of a synthetic polymer (2 micrometer in dia): the polymer is sprayed on a wound and an electric field is applied the wound, which now has a lower electric potential and attracts collagen forming fibroblasts, that recreate the original collagen fiber patterns.

3.  CHITOSAN - a chitin based material derived from crab shells, may help provides a scaffold for skin cell growth.  Applied in a 3 layer dressing: a) Chitosan on teflon sheets, b) a starch-based polymer (which helps transport away pus and edema),  and cotton gause. The body absorbs the Chitosan leaving new skin in its place.

4.  OaSIS - Small Intestine Sub-mucosa
          a complex of collagen fibers and growth factors found in a common throw-away product from pork production (1 pig can give 90 feet of SIS.  The complex can make an excellent framework for tissue growth without scarring.  The pig SIS is washed, sterilized, tripped of unwanted cells and freeze-dried (it looks like parchment paper).   When applied to a wound it promotes blood vessel growth and the SIS is reabsorbed as it replaces the wounded cells.

 
 
 
 

 

 

 

cmallery - july 2000
last update -
March 30, 2007