Porous iron-reinforced polylactic acid TPMS bio-scaffolds: Interlocking reinforcement and synergistic degradation

Abstract

Porous materials are expected to bring a positive impact on enhancing interfaces and mechanics due to their unique pore networks. Herein, porous iron (pFe) was used as the reinforcing phase to strengthen poly (lactic acid) (PLA) matrix, and PLA/pFe scaffolds were prepared via selective laser sintering (SLS) technique. Scaffold models were constructed using triply periodic minimal surfaces (TPMS) and the optimal porosity was obtained by mechanical evaluation. The results showed that pFe incorporation significantly improved mechanical properties, especially for PLA/5pFe scaffold, which was 121% higher than that of PLA scaffold. It may be that molten PLA molecules penetrate the pore network of pFe particles, forming spatial interlocks and encapsulations, thereby improving the efficiency of stress transfer. In addition, a chemical catalytic cycle is expected to be formed between PLA hydrolysis and pFe degradation to promote the degradation of composite scaffolds. Moreover, the composite scaffold also showed good biomineralization and cytocompatibility in vitro. These properties make the PLA/pFe composite scaffold promising for bone tissue engineering applications.

Keywords

• TPMS Scaffold
• Porous iron
• Interlocking reinforcement
• Synergistic degradation
• Cytocompatibility