Keng-Liang Ou

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.

In this study, an innovative hierarchical porous oxide surface (HPOS) with an increased surface area was developed on biomedical 316L stainless steel (SS) implants to promote early bone and implant integration. The surface features and in vivo performance of the HPOS implant were examined using field-emission scanning electron microscopy, nanoindenter, roughness measurement instrument, contact angle goniometer, micro-computed tomography, and histological analysis. Results showed that the HPOS consisted of a hybrid micro-nano-pores structure and had a relatively low elastic modulus (150.6 ± 7.8 GPa, *p < 0.05), high roughness (8.6 ± 1.2 μm, **p < 0.01), and a low contact angle (15.6 ± 1.8°, ***p < 0.001). Additionally, rapid new bone formation was observed on the HPOS of the 316L SS implant modified at 5 V for 5 min, producing pore sizes from approximately 300 nm to 13.5 μm, with bone contact interfaces exceeding 64% at 12 weeks. The HPOS maintained mechanical interlocking ability at the microscale, which positively influenced osseointegration. Moreover, the difference in new bone formation thickness between the unmodified control group (0.45 ± 0.11 mm) and the modified 316L SS implant with HPOS (0.66 ± 0.13 mm) was statistically significant at 12 weeks post-implantation (*p < 0.05). These findings suggest that forming an innovative HPOS on a 316L SS implant could offer a potential solution to enhance early-stage osseointegration in clinical applications.

Background: Tooth extraction procedures often lead to bone resorption, which can have adverse effects on the dimensions of the alveolar ridge. Research has shown that socket preservation techniques using bone graft substitutes can effectively minimize early bone loss in such cases. α–calcium sulfate hemihydrate (α-CSH) has garnered significant attention as a potential bone graft material due to its favorable properties, including osteoconductivity, angiogenic potential, and biocompatibility. Considering these facts, we developed a preliminary protocol for applying α-CSH in addressing alveolar bone loss following tooth extraction. Objective: This research’s general objective is to evaluate the feasibility and initial effectiveness of α-CSH as bone-inducing graft material for socket preservation after tooth extraction. Methods: This preliminary clinical trial will involve 30 fresh extraction sockets from individuals aged 18-35 years. The participants will be divided into 2 groups: one group will receive α-CSH graft material after tooth extraction for socket preservation, while the other group will not receive any graft material. Throughout the study, the participants will be closely monitored for safety measures, which will include clinical examinations, radiographic imaging, and blood tests. Radiographic imaging will be used extensively to assist the progress of bone formation. Results: The study commenced enrollment in August 2022 and is scheduled to conclude post assessments and analyses by the end of 2023. The results of the study are anticipated to be accessible in late 2024. Conclusions: This clinical study represents the initial investigation in humans to assess the feasibility and efficacy of α-CSH in alveolar bone regeneration. We hypothesize that the inclusion of α-CSH can greatly expedite the process of bone formation within fresh sockets, resulting in a swift restoration of bone height without the disadvantages associated with harvesting autogenous bone graft. Trial Registration: Indonesia Registry Center INA-D02FAHP; https://tinyurl.com/2jnf6n3s International Registered Report Identifier (IRRID): DERR1-10.2196/49922

BACKGROUND Tooth extraction procedures often lead to bone resorption, which can have adverse effects on the dimensions of the alveolar ridge. Research has shown that socket preservation techniques using bone graft substitutes can effectively minimize early bone loss in such cases. α–calcium sulfate hemihydrate (α-CSH) has garnered significant attention as a potential bone graft material due to its favorable properties, including osteoconductivity, angiogenic potential, and biocompatibility. Considering these facts, we developed a preliminary protocol for applying α-CSH in addressing alveolar bone loss following tooth extraction. OBJECTIVE This research’s general objective is to evaluate the feasibility and initial effectiveness of α-CSH as bone-inducing graft material for socket preservation after tooth extraction. METHODS This preliminary clinical trial will involve 30 fresh extraction sockets from individuals aged 18-35 years. The participants will be divided into 2 groups: one group will receive α-CSH graft material after tooth extraction for socket preservation, while the other group will not receive any graft material. Throughout the study, the participants will be closely monitored for safety measures, which will include clinical examinations, radiographic imaging, and blood tests. Radiographic imaging will be used extensively to assist the progress of bone formation. RESULTS The study commenced enrollment in August 2022 and is scheduled to conclude post assessments and analyses by the end of 2023. The results of the study are anticipated to be accessible in late 2024. CONCLUSIONS This clinical study represents the initial investigation in humans to assess the feasibility and efficacy of α-CSH in alveolar bone regeneration. We hypothesize that the inclusion of α-CSH can greatly expedite the process of bone formation within fresh sockets, resulting in a swift restoration of bone height without the disadvantages associated with harvesting autogenous bone graft. CLINICALTRIAL Indonesia Registry Center INA-D02FAHP; https://tinyurl.com/2jnf6n3s INTERNATIONAL REGISTERED REPORT DERR1-10.2196/49922

The present study was to investigate the rheological property, printability, and cell viability of alginate–gelatin composed hydrogels as a potential cell-laden bioink for three-dimensional (3D) bioprinting applications. The 2 g of sodium alginate dissolved in 50 mL of phosphate buffered saline solution was mixed with different concentrations (1% (0.5 g), 2% (1 g), 3% (1.5 g), and 4% (2 g)) of gelatin, denoted as GBH-1, GBH-2, GBH-3, and GBH-4, respectively. The properties of the investigated hydrogels were characterized by contact angle goniometer, rheometer, and bioprinter. In addition, the hydrogel with a proper concentration was adopted as a cell-laden bioink to conduct cell viability testing (before and after bioprinting) using Live/Dead assay and immunofluorescence staining with a human corneal fibroblast cell line. The analytical results indicated that the GBH-2 hydrogel exhibited the lowest loss rate of contact angle (28%) and similar rheological performance as compared with other investigated hydrogels and the control group. Printability results also showed that the average wire diameter of the GBH-2 bioink (0.84 ± 0.02 mm (*** p < 0.001)) post-printing was similar to that of the control group (0.79 ± 0.05 mm). Moreover, a cell scaffold could be fabricated from the GBH-2 bioink and retained its shape integrity for 24 h post-printing. For bioprinting evaluation, it demonstrated that the GBH-2 bioink possessed well viability (>70%) of the human corneal fibroblast cell after seven days of printing under an ideal printing parameter combination (0.4 mm of inner diameter needle, 0.8 bar of printing pressure, and 25 °C of printing temperature). Therefore, the present study suggests that the GBH-2 hydrogel could be developed as a potential cell-laden bioink to print a cell scaffold with biocompatibility and structural integrity for soft tissues such as skin, cornea, nerve, and blood vessel regeneration applications.