β-TCP from 3D-printed composite scaffolds acts as an effective phosphate source during osteogenic differentiation of human mesenchymal stromal cells

Emerging Technologies to Enhance Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells: Focus on Nanomaterials and Bioactive Compounds

Bone tissue damage and associated disorders significantly compromise the quality of life of affected patients, and existing therapeutic options remain limited. Bone marrow mesenchymal stem cells (BMSCs) play a crucial role in bone regenerative medicine, owing to their ability to differentiate into osteoblasts. Utilizing cutting-edge technologies, nanomaterials, and bioactive compounds can emulate the natural bone tissue microenvironment, offer a three-dimensional scaffold that facilitates the osteogenic differentiation of BMSCs, and modulate signals at the molecular level, thereby showing promise for applications in bone regeneration and repair. This review seeks to discuss the latest research advancements, elucidate the underlying mechanisms, and highlight the potential benefits of these technologies in augmenting the osteogenic capacity of BMSCs. Furthermore, the challenges and future directions for integrating these technologies in practical settings are discussed to pioneer new vistas in bone regenerative medicine.

The Influence of Physiological Blood Clot on Osteoblastic Cell Response to a Chitosan-Based 3D Scaffold-A Pilot Investigation

BACKGROUND

The use of ex vivo assays associated with biomaterials may allow the short-term visualization of a specific cell type response inserted in a local microenvironment. Blood is the first component to come into contact with biomaterials, providing blood clot formation, being substantial in new tissue formation. Thus, this research investigated the physiological blood clot (PhC) patterns formed in 3D scaffolds (SCAs), based on chitosan and 20% beta-tricalcium phosphate and its effect on osteogenesis. Initially, SCA were inserted for 16 h in rats calvaria defects, and, after that, osteoblasts cells (OSB; UMR-106 lineage) were seeded on the substrate formed. The groups tested were SCA + OSB and SCA + PhC + OSB. Cell viability was checked by MTT and mineralized matrix formation in OSB using alizarin red (ARS). The alkaline phosphatase (ALP) and bone sialoprotein (BSP) expression in OSB was investigated by indirect immunofluorescence (IF). The OSB and PhC morphology was verified by scanning electron microscopy (SEM).

RESULTS

The SCA + PhC + OSB group showed greater cell viability (p = 0.0169). After 10 days, there was more mineralized matrix deposition (p = 0.0365) and high ALP immunostaining (p = 0.0021) in the SCA + OSB group. In contrast, BSP was more expressed in OSB seeded on SCA with PhC (p = 0.0033).

CONCLUSIONS

These findings show the feasibility of using PhC in ex vivo assays. Additionally, its inclusion in the experiments resulted in a change in OSB behavior when compared to in vitro assays. This "closer to nature" environment can completely change the scenario of a study.

Absorbable calcium and phosphorus bioactive membranes promote bone marrow mesenchymal stem cells osteogenic differentiation for bone regeneration

Large segmental bone defects are commonly operated with autologous bone grafting, which has limited bone sources and poses additional surgical risks. In this study, we fabricated poly(lactide-co-glycolic acid) (PLGA)/β-tricalcium phosphate (β-TCP) composite membranes by electrostatic spinning and further promoted osteogenesis by regulating the release of β-TCP in the hope of replacing autologous bone grafts in the clinical practice. The addition of β-TCP improved the mechanical strength of PLGA by 2.55 times. Moreover, β-TCP could accelerate the degradation of PLGA and neutralize the negative effects of acidification of the microenvironment caused by PLGA degradation. In vitro experiments revealed that PLGA/TCP10 membranes are biocompatible and the released β-TCP can modulate the activity of osteoblasts by enhancing the calcium ions concentration in the damaged area and regulating the pH of the local microenvironment. Simultaneously, an increase in β-TCP can moderate the lactate content of the local microenvironment, synergistically enhancing osteogenesis by promoting the tube-forming effect of human umbilical vein endothelial cells. Therefore, it is potential to utilize PLGA/TCP bioactive membranes to modulate the microenvironment at the site of bone defects to promote bone regeneration.