The extracts of bredigite bioceramics enhanced the pluripotency of human dental pulp cells

Bioceramics for Guided Bone Regeneration: A Multicenter Randomized Controlled Trial

OBJECTIVES

To compare the clinical effectiveness of a novel bioceramic (BC) with a control xenograft (BO) for guided bone regeneration (GBR) performed simultaneously with implant placement.

MATERIALS AND METHODS

This clinical study enrolled patients with insufficient bone volume who required GBR during implant placement to increase bone width using either BC or BO. Outcome measures included a dimensional reduction in buccal bone thickness measured by cone beam computed tomography performed immediately post-surgery and at 6 months postoperatively (ΔHBBT), soft tissue healing at 14 days, 1 month, and 6 months postoperatively, and complications rates. The primary outcome was the change in buccal bone thickness around the implant.

RESULTS

Of the total 152 patients included, 76 from each group received BC and BO treatments. The ΔHBBT in BC and BO groups were -0.276 mm (-0.432, -0.121) and -0.614 mm (-0.769, -0.459) mm, respectively, rejecting the null hypothesis. No significant difference in soft tissue healing was observed between the two groups, with no inflammatory changes in 96.05% and 90.79% of the BC and BO groups, respectively, at 2 weeks postoperatively. However, the BC group exhibited a lower overall complication rate (3.95%), including mild inflammation, poor soft tissue healing, and bone graft extrusion in 3 out of 76 patients.

CONCLUSIONS

Both BC and BO demonstrated favorable outcomes in bone regeneration and soft tissue healing when used for simultaneous implant placement and bone augmentation.

The 3D-Printed Ordered Bredigite Scaffold Promotes Pro-Healing of Critical-Sized Bone Defects by Regulating Macrophage Polarization

Background

Repairing critical-sized bone defects secondary to traumatic or tumorous damage is a complex conundrum in clinical practice; in this case, artificial scaffolds exhibited preferable outcomes. Bredigite (BRT, Ca₇MgSi₄O₁₆) bioceramic possesses excellent physicochemical properties and biological activity as a promising candidate for bone tissue engineering.

Methods

Structurally ordered BRT (BRT-O) scaffolds were fabricated by a three-dimensional (3D) printing technique, and the random BRT (BRT-R) scaffolds and clinically available β-tricalcium phosphate (β-TCP) scaffolds were compared as control groups. Their physicochemical properties were characterized, and RAW 264.7 cells, bone marrow mesenchymal stem cells (BMSCs), and rat cranial critical-sized bone defect models were utilized for evaluating macrophage polarization and bone regeneration.

Results

The BRT-O scaffolds exhibited regular morphology and homogeneous porosity. In addition, the BRT-O scaffolds released higher concentrations of ionic products based on coordinated biodegradability than the β-TCP scaffolds. In vitro, the BRT-O scaffolds facilitated RWA264.7 cells polarization to pro-healing M2 macrophage phenotype, whereas the BRT-R and β-TCP scaffolds stimulated more pro-inflammatory M1-type macrophages. A conditioned medium derived from macrophages seeding on the BRT-O scaffolds notably promoted the osteogenic lineage differentiation of BMSCs in vitro. The cell migration ability of BMSCs was significantly enhanced under the BRT-O-induced immune microenvironment. Moreover, in rat cranial critical-sized bone defect models, the BRT-O scaffolds group promoted new bone formation with a higher proportion of M2-type macrophage infiltration and expression of osteogenesis-related markers. Therefore, in vivo, BRT-O scaffolds play immunomodulatory roles in promoting critical-sized bone defects by enhancing the polarization of M2 macrophages.

Conclusion

3D-printed BRT-O scaffolds can be a promising option for bone tissue engineering, at least partly through macrophage polarization and osteoimmunomodulation.

Stimulation of Osteogenic Differentiation of Induced Pluripotent Stem Cells (iPSCs) Using Bioactive Glasses: An in vitro Study

Selection and use of an optimal cell source for bone tissue engineering (BTE) remain a challenging issue; the invention of induced pluripotent stem cells (iPSCs) have created new hopes on this regard. At the present study, we attempted to show the usability of iPSCs in combination with bioactive glasses (BGs) for bone regeneration applications. For this aim, iPSCs were cultured and incubated with the strontium and cobalt-containing BGs for different intervals (1, 5, and 7 days). The cell cytotoxicity and attachment were assessed using MTT assay and scanning electron microscopy (SEM), respectively. Moreover, the osteogenic differentiation of iPSCs seeded onto the glasses was evaluated using alkaline phosphatase (ALP) activity assay and real-time PCR. The obtained results clarified that although the cell viability is decreased during a 7 day period, the iPSCs could adhere and expand onto the BGs particles and over-express the osteogenic markers, including osteocalcin, osteonectin, and Runx2. Based on the data, we conclude that iPSCs in a combination of BGs can be considered as a potential candidate for BTE strategies.