1. Are there any external resources that can be used by the damaged component?
Answer: Yes
2. Do these external resources directly replace the damaged component?
Answer: Yes
3. Can the repair begin without an external energy resource?
Answer: No
4. Does the external resource belong to the original mechanism?
Answer: Yes
12) Bioengineered skin grafts for venous leg and diabetic foot ulcers
Humans can get ulcers on their legs and feet that donÕt heal properly. Scientists have designed bilayered bioengineered skin substitute (BBSS) to replace the ulcers and prevent problems (Curran & Plosker). One type of bioengineered skin is Aligraf which uses neonatal foreskin keratinocytes and fibroblasts, while in a bovine type 1 collagen matrix (Curran & Plosker). The keratinocytes and fibroblasts are stored in cryopreservation vials to be used later. When the time comes for their use keratinocytes are proliferated and differentiate into the epidermal layer in the same culture that the fibroblasts are proliferating differentiating into the dermal layer. These layers are later incubated which produces a stratum corneum and makes the complete skin graft (ÒHow Is It Made?Ó). It has been found that BBSS does not produce antigen-presenting cells which allows the recipients body to have a better chance of not rejecting the skin graft (Curran & Plosker). Once the skin has been put in place on the recipient the surgeons stitch it on and place a dressing over it. Blood vessels will also form from endothelial
cells given off by the recipients mesoderm. This allows for the grafted skin to receive blood. Over time the epithelial cells in the epidermis proliferate and fill in the space between the recipients skin and the grafted skin.
Curran, M. P., and G. L. Plosker. “Bilayered Bioengineered Skin Substitute (Apligraf): A Review of Its Use in the Treatment of Venous Leg Ulcers and Diabetic FootUlcers.” BioDrugs 16.6 (2002):439-55. NCBI. Web. 15 Jan. 2015.
http://www.ncbi.nlm.nih.gov/pubmed/12463767
“How Is It Made?” Apligraf: How Is It Made? Apligraf, 2010. Web. 16 Jan. 2015.
http://www.apligraf.com/professional/what_is_apligraf/how_is_it_made/
Recent Comments