طراحي و ساخت داربست استخوان فك با پليمر زيستي به روش ساخت استريوليتوگرافي با ماسك نوري و مقايسه خواص ناهمسانگرد مدول الاستيسيته با نتايج شبيه‌سازي

The repair of man‎dibular bone defects represents a significant challenge in tissue engineering an‎d maxillofacial surgery. This complexity stems from the multi-layered architecture an‎d the anisotropic mechanical behavior of the man‎dibular bone, which typically consists of dense outer an‎d inner layers surrounding a cancellous core, exhibiting non-uniform mechanical properties along its primary axes. Therefore, designing a scaffold capable of mimicking this multi-layered architecture an‎d anisotropic response is essential. This study focuses on the design, eva‎luation, an‎d fabrication of biomimetic, gyroid-based scaffolds for man‎dibular bone regeneration. Initially, the mechanical properties of the man‎dible, including the elastic modulus in three primary directions, were eva‎luated. The gyroid structure was selec‎ted as the base geometry due to its superior geometric interconnectivity, uniform stress distribution, interconnected porosity, an‎d suitability for additive manufacturing. To enhance modeling accuracy, the man‎dible was segmented into three regions (anterior, middle, an‎d posterior), each comprising three layers (dense outer, cancellous middle, an‎d dense inner), resulting in a comprehensive nine-zone model with distinct mechanical an‎d geometric properties. To achieve a graded transition in mechanical properties an‎d minimize stress concentrations at the interfaces, transitional layers with controlled geometric parameters were integrated. Finite Element Analysis (FEA) was then employed to optimize the scaffold geometries for targeting specific elastic moduli in various directions. Simulation results indicated that scaffold relative density ranged from 20.3% to 57.8%, yielding a Young’s modulus between 0.050 an‎d 3.297 GPa, consistent with the native man‎dibular bone. Following optimization, the scaffolds were fabricated using mask-based photopolymerization an‎d subjected to compression testing. The experimental elastic moduli ranged from 0.054 to 3.084 GPa, with a maximum deviation of 14.2% from the FEA predictions. The findings demonstrate that the designed scaffolds effectively replicate the graded mechanical properties, the architectural distinction between dense an‎d cancellous layers, an‎d the anisotropic behavior of the man‎dible. This development represents a significant advancement in the creation of personalized, biomimetic scaffolds for man‎dibular bone repair.

مهدي كاظمي

عليرضا فدائي تهراني , پيمان مصدق