Another feather on the cap of IIT Delhi as they 3D printed a human skin. The bioprinted skin has a certain anatomically relevant structural, mechanical and biochemical features similar to native human skin. The produced skin is already being used by ITC Ltd for experiments.
The skin is composed of two important layers — the inner dermis (made of fibroblasts) and the outer epidermis (keratinocytes, melanocytes). The junction between the two layers is not flat but is undulatory or wavy. The undulatory morphology is important as it provides biochemical cues and mechanical support to the epidermis layer, provides structural stability to the skin by making the two layers adhere to each other, and not allow cells to cross the junction.
Unlike the currently available tissue-engineered skin equivalents, the team led by Sourabh Ghosh from the institute’s Department of Textile Technology was successful in creating this wavy junction in the bioprinted skin model. The results were published in the journal Bioprinting. The study was funded by ITC Ltd.
The undulatory junction was designed using 3D CAD and 10 layers of dermis were constructed through bioprinting followed by eight layers of epidermis. “We designed the pattern so that both layers fit and the interface had a wavy pattern,” says Prof. Ghosh. Silk bioink mixed with fibroblasts was used for growing the dermis, while bioink mixed with keratinocytes and melanocytes was used for growing the epidermis.
The bioprinted skin also retained the original dimension without any shrinkage for up to three weeks. Traditionally, collagen used for developing skin constructs start shrinking within a few weeks thus affecting the morphology. Testing on such skin constructs therefore cannot be carried out beyond one week.
The bioprinted skin model will have wide applications in testing cosmetics. It can also reduce and probably even replace testing on animals. It can also be used for testing dermatology drugs on human skin and at a future date even help in testing drugs for personalised medicine.