Antibacterial properties and bioactivity of HACC- and HACC-Zein-modified mesoporous bioactive glass scaffolds

Infection and its complications are one of the greatest threats to the health of orthopedic patients. Mesoporous bioglass (MBG) scaffolds are characterized by well-ordered, three-dimensional, nanometer-sized mesoporous structures, which facilitate the adhesion of hydroxyapatite and the loading of drugs. MBG has been widely used as a new-generation biomaterial in bone tissue engineering. However, MBG is very brittle and lacks antibacterial activity. This limits its applications in the treatment of bone defects, especially large bone defects complicated by infection. In order to dispel these disadvantages, a novel hydroxypropyltrimethyl ammonium chloride chitosan (HACC) and a class of prolamine proteins found in maize, Zeins, were here used to modify the traditional MBG scaffolds. Two new types of scaffold, MBG-HACC scaffolds and MBG-HACC-Zein scaffolds, were made. Transmission electron microscopy (TEM), small angle X-ray diffraction (SAXRD), and Barrett-Joyner-Halenda (BJH) were used to analyze the surface properties of these MBG scaffolds. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), mechanical experiments, and synchrotron radiation microcomputer tomography (SRμCT) were used to compare the features of the traditional and modified scaffolds and to analyze the mineralization of the scaffold after being soaked in simulated body fluid (SBF). Confocal laser scanning microscopy (CLSM) was used to compare the antibacterial properties and biocompatibility of the scaffolds at various points in time. The current study demonstrates that all these prepared MBG scaffolds possessed well-ordered, three-dimensional, nanometer-sized mesoporous structures and that HACC-Zein-modified MBG scaffolds are characterized by strong bioactivity and by effective, prolonged antibacterial activity. Finally, biocompatibility was demonstrated by studying the in vitro proliferation and viability of human mesenchymal stem cells (hMSCs).