Auricle shaping using 3D printing and autologous diced cartilage

Current auricle reconstruction techniques face limitations in achieving natural shape and mechanical properties. While traditional grafting methods rely on cartilage shaping, they often lack structural fidelity and long-term viability. Prior research has shown that autologous cartilage grafts can integrate well, but maintaining the desired morphology remains a challenge. The need for a mold that supports cartilage fusion while allowing extracellular matrix development has remained unmet. Existing studies have explored 3D printing for anatomical modeling, but few have combined it with autologous cartilage and growth factors. The gap motivating this work lies in the lack of a reproducible method for auricle shaping that preserves both form and function. This paper introduces a novel approach using 3D-printed molds and PRP to enhance cartilage integration. The study aims to address these limitations by testing a new reconstruction strategy in an animal model.

This study aimed to develop and test a method for auricle reconstruction using a 3D-printed mold and autologous diced cartilage. The specific problem addressed is the difficulty of maintaining auricle shape and viability during reconstruction. The motivation stems from the need for a reliable, anatomically accurate technique that supports cartilage fusion. The authors propose using a porous mold to guide cartilage integration and PRP to enhance cell viability. The study tests whether this method can produce a structurally sound auricle with natural mechanical properties. The approach combines 3D printing with biological grafting to improve outcomes in auricle reconstruction. The goal is to demonstrate that this method can achieve high fidelity to natural auricle anatomy and function. The study focuses on validating this method in a controlled animal model.

The researchers used Materialise Magics v20.03 to design a 3D-printed auricle mold with a porous structure. Ten molds were printed using selective laser sintering with polyamide material. Cartilage was harvested from New Zealand rabbits and diced into small pieces. Platelet-rich plasma was prepared from the same animals to mix with the cartilage. The cartilage-PRP mixture was placed into the hollow mold and implanted onto the rabbits' backs for four months. Histological analysis was performed to assess chondrocyte viability and matrix production. Biomechanical testing measured the stiffness of the reconstructed auricles. The study evaluated shape fidelity, weight retention, and mechanical properties of the grafts.

The 3D-printed molds were 0.6 mm thick with interconnected pores of 0.1 to 0.3 cm. After four months, the diced cartilage fused into an auricle shape with high anatomical fidelity. The weight of the cartilage remained stable at 5.157 ± 0.230 g. Histological staining showed viable chondrocytes and extracellular matrix components like collagen II and glycosaminoglycans. The reconstructed auricles exhibited stiffness of 0.158 ± 0.187 N/mm, similar to human auricles. The mold supported cartilage integration without structural collapse. The PRP mixture enhanced cell viability and matrix production. The results suggest this method can produce functional auricle grafts with natural shape and mechanical properties.

The authors conclude that the 3D-printed mold successfully guided cartilage fusion into an auricle shape. The method preserved cartilage viability and produced appropriate extracellular matrix components. The reconstructed auricles showed mechanical properties comparable to human tissue. The study demonstrates the feasibility of using 3D printing and PRP for auricle reconstruction. The results suggest this approach could improve anatomical accuracy in auricle grafting. The method may provide a reproducible solution for auricle shaping in clinical settings. The findings support further exploration of this technique in larger animal models. The study highlights the potential of combining 3D printing with autologous cartilage for tissue engineering.