Fabrication and in vitro characterization of three-dimensional organic/inorganic scaffolds by robocasting

TL;DR

This study demonstrates the fabrication of hybrid organic/inorganic scaffolds with controlled microstructures using robotic assisted deposition, showing promising mechanical properties and bioactivity suitable for tissue engineering applications.

Contribution

It introduces a novel room-temperature robocasting method for creating customizable, bioactive hybrid scaffolds with controlled porosity and composition for tissue engineering.

Findings

Hybrid scaffolds with 200-500 μm pores were successfully fabricated.

Inorganic content increased scaffold stiffness without brittleness.

Scaffolds maintained properties after 20 days in simulated body fluid.

Abstract

A key issue for the fabrication of scaffolds for tissue engineering is the development of processing techniques flexible enough to produce materials with a wide spectrum of solubility (bioresorption rates) and mechanical properties matching those of calcified tissues. These techniques must also have the capability of generating adequate porosity to further serve as a framework for cell penetration, new bone formation, and subsequent remodeling. In this study, we show how hybrid organic/inorganic scaffolds with controlled microstructures can be built using robotic assisted deposition at room temperature. Polylactide or polycaprolactone scaffolds with pore sizes ranging between 200-500 {\mu}m and hydroxyapatite contents up to 70 wt % were fabricated. Compressive tests revealed an anisotropic behavior of the scaffolds, strongly dependent on their chemical composition. The inclusion of an inorganic component increased their stiffness but they were not brittle and could be easily machined even for ceramic contents up to 70 wt%. The mechanical properties of hybrid scaffolds did not degrade significantly after 20 days in simulated body fluid. However, the stiffness of pure polylactide scaffolds increased drastically due to polymer densification. Scaffolds containing bioactive glasses were also printed. After 20 days in simulated body fluid they developed an apatite layer on their surface.