Breakthrough in microtia treatment

Researchers of the Tissue Engineering and Biofabrication Laboratory of the ETH Zurich unveiled a novel approach to addressing microtia, a congenital condition affecting approximately 1.46 in 10,000 children worldwide. Microtia, characterised by malformed ears, significantly impacts affected children’s self-esteem and overall well-being.

Yesterday – on October 4^th – a study funded by the Swiss national science foundation and published in Science Advances introduced a pioneering solution to this problem. Their method involves the fusion of tissue-engineered human skin and bioprinted cartilage, providing a potential transplantable ear for microtia patients. The team successfully demonstrated the viability of this approach by integrating the engineered ear onto immunocompromised rats.

The novelty of this procedure lies in the combination of advanced tissue engineering techniques. The team utilised hyaluronan transglutaminase and cartilage cells to bioprint the outer ear, or auricle. Simultaneously, they developed pigmented and vascularised skin using human skin cells and collagen hydrogels. By maturing the printed auricle for up to 17 weeks and preparing the dermis and epidermis with human skin cells, the researchers created two distinct tissue-engineered constructs: 3D cartilage and skin. Following in vitro mechanical testing of both components, the researchers transplanted them onto immunocompromised rats. A critical factor in the success of the transplant was the integration to the rat’s vasculature, which occurred within a week, enabling blood perfusion and skin maturation.

Traditionally, the gold standard for treatment involves cartilage harvesting from the ribcage, a complex procedure often deferred until patients reach the age of 10 due to its challenges. Existing alternatives, such as polyethylene implants, come with their own set of complications, including infections and skin contraction. This new technique eliminates the need for ribcage cartilage harvesting, allowing for operations at an earlier age, thereby addressing a crucial limitation of existing treatments.  Future studies will explore larger transplants and diverse animal models to ensure the method’s efficacy and safety.