Advances in the Development of Auricular Cartilage Bioimplants

Conditions such as congenital abnormalities, cancer, infections, and trauma can severely impact the integrity of the auricular cartilage, resulting in the need for a replacement structure. Current implants, carved from the patient's rib, involve multiple surgeries and carry risks of adverse events such as contamination, rejection, and reabsorption. Tissue engineering aims to develop lifelong auricular bioimplants using different methods, different cell types, growth factors and maintenance media formulations, and scaffolding materials compatible with the host. This review aims to examine the progress in auricular bioengineering, focusing on improvements derived from in vivo models and clinical trials, as well as the author's suggestions to enhance the methods. For this scope review, 30 articles were retrieved through Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, plus 6 manually selected articles. The methods reported in the articles were categorized into four levels according to the development phases: source of cells, cell media supplementation, scaffold, or scaffold-free methods, and experimental in vivo or clinical approaches. Many methods have demonstrated potential for the development of bioimplants; four clinical trials reported a structure like the external ear that could be maintained after overcoming post-transplant inflammation. However, several challenges must be solved, such as obtaining a structure that accurately replicates the shape and size of the patient's healthy contralateral auricle and improvements to avoid immunological rejection and resorption of the bioimplant.