The effects of anodized titanium (Ti) with a potential hydrogen fluoride (HF) acid pretreatment through cathodization on the formation of nano-porous Ti dioxide (TiO₂) layer were characterized using field-emission scanning electron microscopy, grazing incidence X-ray diffractometer, and contact angle goniometer. The biocompatibility was determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test. Analytical results found that a well-aligned nano-porous structure was formed on the anodized Ti surface with HF pretreatment concentration above 0.5%. Microstructure of the nano-porous Ti dioxide surface generated by anodization with HF pretreatment was composed of anatase and rutile phases, while the anodized Ti sample with HF pretreatment concentration of 0.5% presented excellent hydrophilicity surface. An in-vitro biocompatibility also indicated that osteoblast cells grown on the surface of the anodized Ti sample with HF pretreatment increased with the increase of culture time. The filopodia of osteoblast cells not only adhered flat, but also tightly grabbed the nano-porous structure for promoting cell adhesion and proliferation. Therefore, the anodized Ti with HF pretreatment can form a functionalized surface with great biocompatibility for biomedical applications, particularly for dental implants.

In this study, we proposed a three-dimensional (3D) printed porous (termed as 3DPP) scaffold composed of bioceramic (beta-tricalcium phosphate (β-TCP)) and thermoreversible biopolymer (pluronic F-127 (PF127)) that may provide bone tissue ingrowth and loading support for bone defect treatment. The investigated scaffolds were printed in three different ranges of pore sizes for comparison (3DPP-1: 150–200 μm, 3DPP-2: 250–300 μm, and 3DPP-3: 300–350 μm). The material properties and biocompatibility of the 3DPP scaffolds were characterized using scanning electron microscopy, X-ray diffractometry, contact angle goniometry, compression testing, and cell viability assay. In addition, micro-computed tomography was applied to investigate bone regeneration behavior of the 3DPP scaffolds in the mini-pig model. Analytical results showed that the 3DPP scaffolds exhibited well-defined porosity, excellent microstructural interconnectivity, and acceptable wettability (θ < 90°). Among all groups, the 3DPP-1 possessed a significantly highest compressive force 273 ± 20.8 Kgf (* p < 0.05). In vitro experiment results also revealed good cell viability and cell attachment behavior in all 3DPP scaffolds. Furthermore, the 3DPP-3 scaffold showed a significantly higher percentage of bone formation volume than the 3DPP-1 scaffold at week 8 (* p < 0.05) and week 12 (* p < 0.05). Hence, the 3DPP scaffold composed of β-TCP and F-127 is a promising candidate to promote bone tissue ingrowth into the porous scaffold with decent biocompatibility. This scaffold particularly fabricated with a pore size of around 350 μm (i.e., 3DPP-3 scaffold) can provide proper loading support and promote bone regeneration in bone defects when applied in dental and orthopedic fields.

This study aimed to investigate the free calcium released from different brands of toothpaste after incorporation with a beta-tricalcium phosphate (β-TCP)/amorphous calcium phosphate (ACP) mixed powder and with β-TCP powder alone. Four brands of toothpaste were used for the experiment: Nano-Bio Activation Toothpaste, Colgate Total Advanced Whitening Toothpaste, BORONIA Herbal Whitening, and BioMin F. The investigated β-TCP and ACP powders were prepared by a two-step sintering method using raw coral material. Analytical results found that the mean calcium concentration of the β-TCP/ACP (2:1) powder in deionized water was 3.4% when the pH was between 5 and 9. Moreover, statistical results revealed that the toothpaste containing β-TCP powder had significantly higher calcium concentrations than the normal toothpaste. The toothpaste containing mixed β-TCP/ACP powder had a higher calcium concentration than the toothpaste containing only β-TCP powder. Twice as much free calcium could be released from β-TCP/ACP toothpaste than from β-TCP-only toothpaste. Thus, toothpaste containing β-TCP/ACP mixed powder offers greater benefits to facilitate the remineralization of enamel than toothpaste containing only β-TCP.

The present study established a maximum standard for printing quality and developed a preliminary ideal index to print three-dimensional (3D) construct using the Gly-Arg-Gly-Asp (GRGD) peptide modified Pluronic-F127 hydrogel (hereafter defined as 3DG bioformer (3BE)) as bioink. In addition, the biocompatibility of 3BE for 3D printing applications was carefully investigated. For biocompatibility study and ideal printing parameter, we used the formulation of 3BE in three different concentrations (3BE-1: 25%, 3BE-2: 30%, and 3BE-3: 35%). The 3BE hydrogels were printed layer by layer as a cube-like construct with all diameters of the needle head under the same feed (100 mm/s). The printing parameters were determined using combinations of 3BE-1, 3BE-2, and 3BE-3 with three different standard needle sizes (Φ 0.13 mm, Φ 0.33 mm, and Φ 0.9 mm). The printed constructs were photographed and observed using optical microscopy. The cell viability and proliferation were evaluated using Live/Dead assay and immunofluorescence staining. Results showed that a stable of printed line and construct could be generated from the 3BE-3 combinations. Cytotoxicity assay indicated that the 3BE hydrogels possessed well biocompatibility. Bioprinting results also demonstrated that significant cell proliferation in the 3BE-3 combinations was found within three days of printing. Therefore, the study discovered the potential printing parameters of 3BE as bioink to print a stable construct that may also have high biocompatibility for cell encapsulation. This finding could serve as valuable information in creating a functional scaffold for tissue engineering applications.

The present study aimed to synthesize biphasic calcium phosphate ceramics (CaPs) composed of β-tricalcium phosphate (β-TCP) and hydroxyapatite (HAp) from the propagated Scleractinian coral and dicalcium phosphate anhydrous using a solid-state reaction followed by heat treatment at a temperature of 1100 °C for 1 h to 7 days. The as-prepared coral and coral-derived biphasic CaPs samples were characterized through scanning electron microscopy, X-ray diffractometry, Fourier transform infrared spectroscopy, and Raman spectroscopy. The cell response of the biphasic CaPs was evaluated by in vitro cytotoxicity assessment using mouse fibroblast (L929) cells. The bilateral femoral defect rabbit model was used to assess the early local reaction of the coral-derived biphasic CaPs bone graft on tissue. The results confirmed that the co-existence of β-TCP and HAp was formed at 1100 °C for 1 h. The ratio of HA/β-TCP increased as the heat-treatment time increased. The coral-derived biphasic CaPs comprising 61% HAp and 39% β-TCP (defined as HT-3) were not cytotoxic. Furthermore, no significant differences in local tissue reaction were observed between the HT-3 sample and autogenous bone. Therefore, the synthesized coral-derived biphasic CaPs is a candidate for bone grafting due to its good biocompatibility.

This study evaluated whether three-dimensional alginate–gelatin hydrogels (AGHs) crosslinked with calcium chloride (CaCl₂) enhance the osteo-odontogenic differentiation of odontoblast-like cells in vitro. Two seeding configurations were compared: inter-hydrogel (INT) surface seeding and intra-hydrogel (INTR) encapsulation. Here, the MDPC-23 cells were cultured in AGHs crosslinked with 70 or 100 mM CaCl₂ and assessed for proliferation, cytoskeletal morphology, alkaline phosphatase (ALPase) activity, osteo-odontogenic gene expression, and mineralized nodule formation. After 7 days, cell proliferation was significantly greater in the alginate–gelatin hydrogel (AGH) groups than in the control group. Cells in the intra alginate–gelatin hydrogel 100 (INTR-AGH100) remained predominantly rounded, whereas those in the inter alginate–gelatin hydrogel 100 (INT-AGH100) formed irregular clusters on the hydrogel surface. ALPase activity was highest in INTR-AGH100 at the early stage of culture. Both INT-AGH100 and INTR-AGH100 showed significantly increased expression of DSPP, DMP-1, BSP, OCN, OPN, and Runx-2, together with enhanced mineralized nodule formation. Although no significant differences were detected between the two seeding strategies in all assays, distinct morphological patterns were observed, and the INTR configuration showed relatively greater early differentiation-related activity. These findings suggest that 100 mM CaCl₂-crosslinked AGHs provide a favorable three-dimensional microenvironment under the present experimental conditions and represent a promising in vitro scaffold platform to support future studies of scaffold-guided dentin regeneration.