Tissue-Engineered Skin Grafts for Burn Victims

Burn injuries can destroy large areas of skin, the body’s protective barrier, and pose immediate risks of fluid loss, infection, and death. For survivors, deep burns leave scars, contractures, and lifelong functional limitations. Traditional skin grafting, which involves harvesting a patient’s own skin or using donor skin, has been the standard for decades. However, it faces serious limitations when burns cover a large surface area or when donor sites are exhausted. To overcome this challenge, scientists and surgeons have developed tissue-engineered skin, which is are living, lab-grown substitute designed to restore both structure and function to damaged tissue.

Cell collection is the first step in the process. The patient has a tiny sample of healthy skin removed, usually only a few square centimetres. Two primary cell types are separated from this sample: fibroblasts, which create the supporting dermal layer underneath, and keratinocytes, which form the outer epidermal layer. These cells are cultivated in nutrient-rich media under sterile laboratory conditions, where they proliferate quickly.

Next comes scaffold fabrication. The scaffold acts as a 3D framework for the cells to attach, grow, and organise. It can be made from natural materials like collagen, fibrin, or hyaluronic acid, or from synthetic polymers such as polylactic acid. The scaffold needs to be biodegradable so that it can dissolve gradually as new skin tissue grows, flexible but strong, and porous enough to allow nutrients and oxygen to permeate through.

Cells are seeded onto the scaffold in discrete layers after the scaffold is prepared.  Fibroblasts are placed first to form the dermal base, followed by keratinocytes that create the epidermal surface. In advanced systems, other cell types (such as melanocytes, endothelial cells, or stem cells) may be added to promote pigmentation, blood vessel growth, and long-term integration. After that, the construct is put in a bioreactor to develop under carefully regulated oxygen, temperature, and humidity levels. The engineered graft develops the fundamental structure of natural skin over a period of days or weeks.

In order to prevent infection, surgeons clean the wound bed and remove any dead tissue from the burn site once it has matured. The engineered graft is carefully applied, often using surgical adhesives or fine sutures to secure it in place. Angiogenesis, the formation of new blood vessels that link the patient's circulation to the implanted tissue, is necessary for successful grafting. This step is crucial for delivering oxygen and nutrients, ensuring the graft survives and integrates into the skin.

As healing progresses, the engineered skin gradually bonds with the surrounding tissue. The scaffold degrades naturally, leaving behind layers of new skin composed of the patient’s own cells. Over time, the regenerated tissue thickens, strengthens, and begins to take on the appearance and elasticity of normal skin. Rehabilitation includes moisturising, physiotherapy, and careful monitoring to prevent scarring and contraction.

by Shanisse Tan at Incisionary

APA References

Reynolds, S. (2023, February 13). Engineering skin grafts for complex body parts. National Institutes of Health (NIH). https://www.nih.gov/news-events/nih-research-matters/engineering-skin-grafts-complex-body-parts.

Przekora, A. (2020, July 6). A concise review on tissue engineered artificial skin grafts for chronic wound treatment: Can we reconstruct functional skin tissue in vitro?. MDPI. https://www.mdpi.com/2073-4409/9/7/1622.

Przekora A. (2020). A Concise Review on Tissue Engineered Artificial Skin Grafts for Chronic Wound Treatment: Can We Reconstruct Functional Skin Tissue In Vitro?. Cells, 9(7), 1622. https://doi.org/10.3390/cells9071622.

Evolution, W. (2023, January 20). Bio-Engineered skin grafts. Wound Evolution. https://www.woundevolution.com/wound-care/wound-treatment/bio-engineered-skin-grafts/.

Phillips TJ. Tissue-Engineered Skin: An Alternative to Split-Thickness Skin Grafts? Arch Dermatol. 1999;135(8):977–978. doi:10.1001/archderm.135.8.977

Phua, Q.H., Han, H.A. & Soh, BS. Translational stem cell therapy: vascularized skin grafts in skin repair and regeneration. J Transl Med 19, 83 (2021). https://doi.org/10.1186/s12967-021-02752-2.

Ye Xu, Xiangyi Wu, Yuanyuan Zhang, Yunru Yu, Jingjing Gan, Qian Tan, Engineered artificial skins: Current construction strategies and applications, Engineered Regeneration, Volume 4, Issue 4, 2023, Pages 438-450, ISSN 2666-1381, https://doi.org/10.1016/j.engreg.2023.09.001.

Chelladurai Karthikeyan Balavigneswaran, Sowmya Selvaraj, T.K. Vasudha, Saravanakumar Iniyan, Vignesh Muthuvijayan, Tissue engineered skin substitutes: A comprehensive review of basic design, fabrication using 3D printing, recent advances and challenges, Biomaterials Advances, Volume 153, 2023, 213570, ISSN 2772-9508, https://doi.org/10.1016/j.bioadv.2023.213570.