Objectives/Goals: We aim to develop new tissue-engineered ear tissue that more closely mimics native elastic cartilage and maintains its topographic form for reconstructive auricular surgery. By integrating decellularized cartilage (DCM) into chondrocyte-seeded collagen matrices, we seek to improve structural stability to support future clinical translation. Methods/Study Population: Bovine auricular chondrocytes were isolated via enzymatic digestion, expanded to passage 3, and encapsulated at 25 million cells/mL into four construct formulations composed of 1% type I collagen mixed with varying amounts of DCM: (1) 100% collagen, (2) 70% collagen + 30% DCM, (3) 40% collagen + 60% DCM, and (4) 10% collagen + 90% DCM. DCM was prepared by zesting ovine rib cartilage into ~0.5 mm³ flakes, followed by chemical and enzymatic decellularization. Constructs were packed into 3D-printed scaffolds and cultured for 0, 1, or 2 months. At each timepoint, constructs were assessed for gross volume, volume retention (normalized to baseline), and angle at the dome–base interface as a geometric surrogate for shape retention. Histology evaluated cell distribution and cartilage-specific matrix deposition. Results/Anticipated Results: At baseline, volumes were comparable across groups. By 1 and 2 months, constructs with higher DCM content yielded significantly greater volume retention. At 2 months, mean retention in the 90% DCM group was 94.0%±6.2%, compared to 64.7%±4.1% in 30% DCM (p<0.01) and 74.7%±5.9% in 0% DCM (p<0.05). Angle analysis likewise showed that higher DCM preserved sharper dome–base curvature. Mean angle change at 2 months was 3.0°±3.6° in 90% DCM versus 17.6°±5.7° (70% DCM, p<0.01), 16.3°±5.7° (30% DCM, p<0.05), and 21.6°±8.1° (0% DCM, p<0.001). In all groups, histology confirmed chondrocyte viability, and inclusion of DCM did not hinder cell distribution in collagen. These findings suggest DCM reinforces construct stability, and we anticipate similar volume and shape retention in upcoming in vivo rat studies. Discussion/Significance of Impact: Incorporating DCM improves in vitro form retention in bioengineered ear cartilage without impeding cell viability, suggesting DCM can act as an internal rebar to resist contraction and preserve geometry. By continuing to advance this construct translationally, next in vivo , we aim to enable its eventual use in clinical ear reconstruction.
Liao et al. (Wed,) studied this question.