Preparation and biocompatibility of diphasic magnetic nanocomposite scaffold

Abstract

We describe the study of a new type of diphasic magnetic nanocomposite scaffold (PLGA/Col-I-PLGA/n-HA/Fe₂O₃) and its preparation using a novel low-temperature deposition manufacturing (LDM) technology. In order to study the biocompatibility of this scaffold, we evaluated and explored its feasibility as a scaffold for tissue engineering. Diphasic magnetic nanocomposite scaffolds (PLGA/Col-I-PLGA/n-HA/Fe₂O₃) were prepared using LDM technology. The mechanical properties of the scaffold were tested using an electronic testing machine, electron microscopy was utilized to observe the ultrastructure, and a medium (ethanol) immersion method was used to determine the porosity of the scaffold. The scaffold was co-cultured with bone mesenchymal stem cells (BMSCs) and was induced to differentiate. The biocompatibility of the scaffold was then tested. The mechanical test results of the diphasic magnetic nanocomposite scaffold demonstrated good mechanical properties. Electron microscopy studies revealed two layers of pore sizes each with a uniform distribution, with the upper cartilage pore size observed to be small while the middle continuous phase was found to be in a good integration. Pore size and porosity test results demonstrated a cartilage layer pore size of 186 μm, with a porosity measured to be 89.5%. The pore size and porosity of the bone layer were 394 μm and 86.1%, respectively. These properties met the design requirements of double layer scaffolds. Co-culture of the diphasic magnetic nanocomposite scaffold and bone mesenchymal stem cells (BMSCs) exhibited good proliferation of bone mesenchymal stem cells (BMSCs), and the scaffold was found to be able to promote differentiation of the differentiation-oriented cells. These results demonstrated a good biocompatibility of the diphasic magnetic nanocomposite scaffold. The diphasic magnetic nanocomposite scaffold (PLGA/Col-I-PLGA/n-HA/Fe₂O₃) was found to have suitable mechanical properties as well as cell compatibility. The measured pore size and porosity met the requirements for cell adhesion and cell growth, which matched more closely to that of the physiological structure of normal articular cartilage and subchondral bones. We expect this to represent new technology for improved repair of cartilage and subchondral bone lesions caused by osteoarthritis or trauma.

Keywords: 3D printing; Diphasic magnetic nanoparticles; Low-temperature deposition manufacturing.