Optimal structural characteristics of bone tissue engineering scaffolds from bionics and PSO-BP-NSGA III integrated algorithm

Abstract

The repair of large segmental bone defects has always been a significant challenge in clinical practice, with stress shielding being one of the key issues. Here, tree-like fractal biomimetic scaffolds were created based on the morphological similarity between natural trees and bone trabeculae. To optimize the balance between high yield strength and low elastic modulus of the scaffold, an integrated particle swarm optimization-backpropagation-non-dominated sorting genetic algorithm III (PSO-BP-NSGA III) was employed. The scaffolds were fabricated using selective laser melting three-dimensional printing with Ti6Al4V, and their mechanical performance was experimentally evaluated and compared with the algorithm’s predictions. The tree-like fractal scaffold exhibited a radial gradient in porosity, similar to that of natural bone. The second-order fractal scaffold achieved an effective synergy between yield strength and Young’s modulus, demonstrating high yield strength and low Young’s modulus. Additionally, it showed a favorable fluid flow gradient and permeability, with a comprehensive permeability of 3.13 × 10−8 m². The relative errors between the test and predicted values of yield strength and Young’s modulus were 0.83% and 7.93% respectively, indicating that the PSO-BP-NSGA III integrated algorithm has good predictive ability. These findings establish a validated bionic design framework that integrates advanced optimization algorithms to guide the development of bone tissue engineering scaffolds.  

 

Keywords

Integrated algorithm / Multi-objective optimization / Stress shielding / Tree-like fractal scaffold / Young’s modulus

Funding

This work was supported by the Natural Science Foundation of Chongqing Municipality (Grant no: CSTB2023NSCQ-MSX0255), the Key Project of Science and Technology Research Program of Chongqing Education Commission (Grant no.: KJZD-K202203104), and the Science and Technology Research Program of Chongqing Education Commission (Grant no.: KJQN202403112).

Conflict of Interest

The authors declare that there is no conflict of interest.

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