Geometry as a Factor for Tissue Growth: Towards Shape Optimization of Tissue Engineering Scaffolds

TLDR

Scaffold design for tissue engineering typically prioritizes large adhesion surfaces and high permeability, but recent studies show that macroscopic geometry also influences tissue deposition kinetics. This study applies a previously proposed osteoblast curvature model to predict bone matrix growth in pores of varying shapes. Predictions were tested using MC3T3‑E1 cells cultured in 2‑mm‑thick hydroxyapatite plates with prismatic square or cross‑shaped pores. Microscopy confirmed the model, revealing that cross‑shaped pores achieve twice the initial tissue deposition rate of square pores, indicating shape optimization can accelerate bone ingrowth.

Abstract

Abstract Scaffolds for tissue engineering are usually designed to support cell viability with large adhesion surfaces and high permeability to nutrients and oxygen. Recent experiments support the idea that, in addition to surface roughness, elasticity and chemistry, the macroscopic geometry of the substrate also contributes to control the kinetics of tissue deposition. In this study, a previously proposed model for the behavior of osteoblasts on curved surfaces is used to predict the growth of bone matrix tissue in pores of different shapes. These predictions are compared to in vitro experiments with MC3T3‐E1 pre‐osteoblast cells cultivated in two‐millimeter thick hydroxyapatite plates containing prismatic pores with square‐ or cross‐shaped sections. The amount and shape of the tissue formed in the pores measured by phase contrast microscopy confirms the predictions of the model. In cross‐shaped pores, the initial overall tissue deposition is twice as fast as in square‐shaped pores. These results suggest that the optimization of pore shapes may improve the speed of ingrowth of bone tissue into porous scaffolds.