Delivery of dimethyloxalylglycine in calcined bone calcium scaffold to improve osteogenic differentiation and bone repair

Effect of Dimethyloxalylglycine on Stem Cells Osteogenic Differentiation and Bone Tissue Regeneration-A Systematic Review

Dimethyloxalylglycine (DMOG) has been found to stimulate osteogenesis and angiogenesis of stem cells, promoting neo-angiogenesis in bone tissue regeneration. In this review, we conducted a comprehensive search of the literature to investigate the effects of DMOG on osteogenesis and bone regeneration. We screened the studies based on specific inclusion criteria and extracted relevant information from both in vitro and in vivo experiments. The risk of bias in animal studies was evaluated using the SYRCLE tool. Out of the 174 studies retrieved, 34 studies met the inclusion criteria (34 studies were analyzed in vitro and 20 studies were analyzed in vivo). The findings of the included studies revealed that DMOG stimulated stem cells' differentiation toward osteogenic, angiogenic, and chondrogenic lineages, leading to vascularized bone and cartilage regeneration. Addtionally, DMOG demonstrated therapeutic effects on bone loss caused by bone-related diseases. However, the culture environment in vitro is notably distinct from that in vivo, and the animal models used in vivo experiments differ significantly from humans. In summary, DMOG has the ability to enhance the osteogenic and angiogenic differentiation potential of stem cells, thereby improving bone regeneration in cases of bone defects. This highlights DMOG as a potential focus for research in the field of bone tissue regeneration engineering.

Insight into the effect of biomaterials on osteogenic differentiation of mesenchymal stem cells: A review from a mitochondrial perspective

Bone damage may be triggered by a variety of factors, and the damaged area often requires a bone graft. Bone tissue engineering can serve as an alternative strategy for repairing large bone defects. Mesenchymal stem cells (MSCs), the progenitor cells of connective tissue, have become an important tool for tissue engineering due to their ability to differentiate into a variety of cell types. The precise regulation of the growth and differentiation of the stem cells used for bone regeneration significantly affects the efficiency of this type of tissue engineering. During the process of osteogenic induction, the dynamics and function of localized mitochondria are altered. These changes may also alter the microenvironment of the therapeutic stem cells and result in mitochondria transfer. Mitochondrial regulation not only affects the induction/rate of differentiation, but also influences its direction, determining the final identity of the differentiated cell. To date, bone tissue engineering research has mainly focused on the influence of biomaterials on phenotype and nuclear genotype, with few studies investigating the role of mitochondria. In this review, we provide a comprehensive summary of researches into the role of mitochondria in MSCs differentiation and critical analysis regarding smart biomaterials that are able to "programme" mitochondria modulation was proposed. STATEMENT OF SIGNIFICANCE: : • This review proposed the precise regulation of the growth and differentiation of the stem cells used to seed bone regeneration. • This review addressed the dynamics and function of localized mitochondria during the process of osteogenic induction and the effect of mitochondria on the microenvironment of stem cells. • This review summarized biomaterials which affect the induction/rate of differentiation, but also influences its direction, determining the final identity of the differentiated cell through the regulation of mitochondria.

One-Pot Facile Encapsulation of Dimethyloxallyl Glycine by Nanoscale Zeolitic Imidazolate Frameworks-8 for Enhancing Vascularized Bone Regeneration

In the process of bone tissue regeneration, regulation of osteogenesis-angiogenesis coupling is of great importance. Therefore, dimethyloxallyl glycine (DMOG) is loaded by nanoscale zeolitic imidazolate frameworks-8 (ZIF-8) to obtain a drug-loading system that can promote osteogenesis-angiogenesis coupling. Characterization of the drug-loading nanoparticles (DMOG@ZIF-8) reveals that DMOG is successfully loaded into ZIF-8 by two different methods, and the DMOG@ZIF-8 is prepared using the one-pot method (OD@ZIF-8) achieves higher loading efficiency and longer release time than those prepared using the post-loading method (PD@ZIF-8). In vitro studies found that DMOG@ZIF-8 significantly enhances the migration, tube formation, and angiogenesis-related protein secretion of human umbilical vein endothelial cells as well as the extracellular matrix mineralization, alkaline phosphatase activity, and osteogenesis-related protein secretion of bone marrow mesenchymal stem cells. Moreover, OD@ZIF-8 nanoparticles are more efficient than PD@ZIF-8 nanoparticles in induction of osteogenesis-angiogenesis coupling. Then, in vivo cranial critical defect model shows that the addition of OD@ZIF-8 significantly promotes vascularized bone formation as indicated by the results including microcomputed tomographic, histological and immunofluorescence staining, and so on. Taken together, loading ZIF-8 with DMOG may be a promising solution for critical-sized bone defect reconstruction and the one-pot method is preferred in the preparation of such drug-loading system.

Vascularized Tumor Spheroid-on-a-Chip Model Verifies Synergistic Vasoprotective and Chemotherapeutic Effects

Prolyl hydroxylases (PHD) inhibitors have been observed to improve drug distribution in mice tumors via blood vessel normalization, increasing the effectiveness of chemotherapy. These effects are yet to be demonstrated in human cell models. Tumor spheroids are three-dimensional cell clusters that have demonstrated great potential in drug evaluation for personalized medicine. Here, we used a perfusable vascularized tumor spheroid-on-a-chip to simulate the tumor microenvironment in vivo and demonstrated that the PHD inhibitor dimethylallyl glycine prevents the degradation of normal blood vessels while enhancing the efficacy of the anticancer drugs paclitaxel and cisplatin in human esophageal carcinoma (Eca-109) spheroids. Our results point to the potential of this model to evaluate anticancer drugs under more physiologically relevant conditions.