In the last few decades, research on biocomposite nanomaterials has grown exponentially due to the global demand for novel solutions in bone tissue engineering and repair. In the present study, it is reported the design and synthesis of biocomposites based on glycol chitosan (GLY-CHI) matrices incorporated with nano-hydroxyapatite particles (nHA) produced via an eco-friendly chemical colloidal process in water media followed by solvent casting and evaporation methods at room temperature. The structure, morphology, and crystallinity of the components and biocomposites were extensively characterized by light microscopy (LM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), wavelength dispersive X-ray fluorescence spectroscopy (WD-XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray micro-computed tomography analysis (μCT). Furthermore, cytotoxicity and cell viability tests were performed on three cell lines using a 3-(4,5-dimethylthiazol-2yl) 2,5-diphenyl tetrazolium bromide (MTT) assay, an alkaline phosphatase (ALP) activity test, and LIVE/DEAD assays. The results demonstrated that the GLY-CHI ligand played a major role in the nucleation, growth and colloidal stabilization of calcium phosphate particles at nanoscale dimensions with a narrow distribution and average size of 74±15nm. The FTIR spectroscopy associated with the XRD results indicated that nanosized hydroxyapatite (nHA) was the predominant calcium phosphate phase produced in the colloidal processing route. In addition, the X-ray micro-CT analysis of the nanocomposite membranes showed that nHA particles were homogenously dispersed in the glycol-chitosan polymeric matrix. Moreover, according to the in vitro bioassays, the biocomposites showed an adequate cell viability response and non-cytotoxic behavior toward osteoblastic-like (SAOS) and embryonic cell lines (HEK293T). Finally, the results of osteogenic differentiation tests demonstrated that the nHA/GLY-CHI composites are osteoinductive for human bone marrow mesenchymal stem cells (HBMS), which can be envisioned for prospective use in tissue engineering (e.g., bone, cartilage and periodontal) applications.

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In this study, conventional restorative glass ionomer cement (GIC) was modified by embedding it with mechanically processed cellulose fibers. Two concentrations of fibers were weighed and agglutinated into the GIC during manipulation, yielding Experimental Groups 2 (G2; 3.62 wt% of fibers) and 3 (G3; 7.24 wt% of fibers), which were compared against a control group containing no fibers (G1). The compressive strengths and elastic modulus of the three groups, and their diametral tensile strengths and stiffness, were evaluated on a universal test machine. The compressive and diametral tensile strengths were significantly higher in G3 than in G1. Statistically significant differences in elastic modulus were also found between G2 and G1 and between G2 and G3, whereas the stiffness significantly differed between G1 and G2. The materials were then characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Heterogeneously shaped particles were found on the G2 and G3 surfaces, and the cement matrices were randomly interspersed with long intermingled fibers. The EDS spectra of the composites revealed the elemental compositions of the precursor materials. The physically processed cellulosic fibers (especially at the higher concentration) increased the compressive and diametral tensile strengths of the GIC, and demonstrated acceptable elastic modulus and stiffness.