Hyaluronic acid-based hydrogels with tobacco mosaic virus containing cell adhesive peptide induce bone repair in normal and osteoporotic rats

Perspectives on Osteoarthritis Treatment with Mesenchymal Stem Cells and Radix Achyranthis Bidentatae

Knee osteoarthritis, a widespread degenerative condition, impacts a younger population and leads to high disability rates. Nature often provides solutions for aging and disease prevention. Mesenchymal stem cells (MSCs) and Radix Achyranthis Bidentatae (AB) are natural substances with potential. MSCs can transform into various tissues, alleviating symptoms by releasing factors and miRNA, potentially slowing osteoarthritis progression. AB's compositions target knee joint cells, enhancing internal conditions and joint function. Both MSCs and AB share mechanisms for immune regulation, reducing cartilage apoptosis, promoting chondrocyte formation, and addressing osteoporosis. They also influence estrogen and gut flora. This article reviews their roles in treating osteoarthritis, discussing apoptosis reduction, chondrocyte growth, bone enhancement, angiogenesis, and regulation of estrogen and intestinal flora. It explores their relationship and suggests AB's potential in stimulating mesenchymal stem cell repair for knee osteoarthritis treatment.

COL6A3 enhances the osteogenic differentiation potential of BMSCs by promoting mitophagy in the osteoporotic microenvironment

BACKGROUND

Bone marrow mesenchymal stem cells (BMSCs) have been widely recognized as a highly promising option for cell-based tissue engineering therapy targeting osteoporosis. However, the osteogenic differentiation of BMSCs is impeded by the limited viability and diminished capacity for bone formation within the osteoporotic microenvironment.

METHODS

In this study, the COL6A3 gene was confirmed through an extensive analysis of the preceding single-cell sequencing database. The generation of an inflammatory microenvironment resembling osteoporotic cell transplantation was achieved by employing lipopolysaccharide (LPS). A lentivirus targeting the COL6A3 gene was constructed, and a Western blotting assay was used to measure the marker proteins of osteogenesis, adipogenesis, and mitophagy. Immunofluorescence was utilized to observe the colocalization of mitochondria and lysosomes. The apoptosis rate of each group was evaluated using the TUNEL assay, and the mitochondrial membrane potential was assessed using JC-1 staining.

RESULTS

This investigation discovered that the impaired differentiation capacity and decreased viability of BMSCs within the inflammatory microenvironment were markedly ameliorated upon overexpression of the specific COL6A3 gene. Moreover, the administration of COL6A3 gene overexpression successfully mitigated the inhibitory impacts of LPS on mitophagy and the expression of inflammatory mediators, specifically inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in BMSCs. To clarify the underlying mechanism, the role of mitophagy during the differentiation of COL6A3 gene-modified BMSCs in the inflammatory microenvironment was evaluated using the mitophagy inhibitor Mdivi-1.

CONCLUSIONS

In the context of lipopolysaccharide (LPS) stimulation, COL6A3 enhances the differentiation of BMSCs into osteogenic and adipogenic lineages through the promotion of mitophagy and the maintenance of mitochondrial health. Our findings may provide a novel therapeutic approach utilizing stem cells in the treatment of osteoporosis.

Organoid extracellular vesicle-based therapeutic strategies for bone therapy

With the rapid development of population ageing, bone-related diseases seriously affecting the life of the elderly. Over the past few years, organoids, cell clusters with specific functions and structures that are self-induced from stem cells after three-dimensional culture in vitro, have been widely used for bone therapy. Moreover, organoid extracellular vesicles (OEVs) have emerging as promising cell-free nanocarriers due to their vigoroso physiological effects, significant biological functions, stable loading capacity, and great biocompatibility. In this review, we first provide a comprehensive overview of biogenesis, internalisation, isolation, and characterisation of OEVs. We then comprehensively highlight the differences between OEVs and traditional EVs. Subsequently, we present the applications of natural OEVs in disease treatment. We also summarise the engineering modifications of OEVs, including engineering parental cells and engineering OEVs after isolation. Moreover, we provide an outlook on the potential of natural and engineered OEVs in bone-related diseases. Finally, we critically discuss the advantages and challenges of OEVs in the treatment of bone diseases. We believe that a comprehensive discussion of OEVs will provide more innovative and efficient solutions for complex bone diseases.

Performance of iCare quantitative computed tomography in bone mineral density assessment of the hip and vertebral bodies in European spine phantom

BACKGROUND

Osteoporosis is a systemic bone disease which can increase the risk of osteoporotic fractures. Dual-energy X-ray absorptiometry (DXA) is considered as the clinical standard for diagnosing osteoporosis by detecting the bone mineral density (BMD) in patients, but it has flaws in distinguishing between calcification and other degenerative diseases, thus leading to inaccurate BMD levels in subjects. Mindways quantitative computed tomography (Mindways QCT) is a classical QCT system. Similar to DXA, Mindways QCT can directly present the density of trabecular bone, vascular or tissue calcification; therefore, it is more accurate and sensitive than DXA and has been widely applied in clinic to evaluate osteoporosis. iCare QCT osteodensitometry was a new phantom-based QCT system, recently developed by iCare Inc. (China). It has been gradually applied in clinic by its superiority of taking 3-dimensional BMD of bone and converting BMD values to T value automatically. This study aimed at evaluating the osteoporosis detection rate of iCare QCT, compared with synchronous Mindways QCT (USA).

METHODS

In this study, 131 patients who underwent hip phantom-based CT scan were included. Bone mineral density (BMD) of the unified region of interests (ROI) defined at the European spine phantom (ESP, German QRM) including L1 (low), L2 (medium), and L3 (high) vertebral bodies was detected for QCT quality control and horizontal calibration. Every ESP scan were taken for 10 times, and the mean BMD values measured by iCare QCT and Mindways QCT were compared. Hip CT scan was conducted with ESP as calibration individually. T-scores gained from iCare QCT and Mindways QCT were analyzed with Pearson correlation test. The detection rates of osteoporosis were compared between iCare QCT and Mindways QCT. The unified region of interests (ROI) was delineated in the QCT software.

RESULTS

The results showed that there was no significant difference between iCare QCT and Mindways QCT in the evaluation of L1, L2, and L3 vertebrae bodies in ESP. A strong correlation between iCare QCT and Mindways QCT in the assessment of hip T-score was found. It was illustrated that iCare QCT had a higher detection rate of osteoporosis with the assessment of hip T-score than Mindways QCT did. In patients < 50 years subgroup, the detection rate of osteoporosis with iCare QCT and Mindways QCT was equal. In patients ≥ 50 years subgroup, the detection rate of osteoporosis with iCare QCT (35/92, 38.0%) was higher than that with Mindways QCT. In female subgroup, the detection rate of osteoporosis with iCare QCT was significantly higher than Mindways QCT. In male subgroup, the detection rate of osteoporosis with iCare QCT was also markedly higher than Mindways QCT. The detection rate of osteoporosis by iCare QCT was higher than Mindways QCT with hip bone assessment. Of course, the results of the present study remain to be further verified by multicenter studies in the future.

Self-Assembled Thermoresponsive Nanogel from Grafted Hyaluronic Acid as a Biocompatible Delivery Platform for Curcumin with Enhanced Drug Loading and Biological Activities

A hyaluronic acid-grafted poly(N-isopropylacrylamide) (HA-pNIPAM) was synthesized as a polymeric nanogel platform for encapsulation and delivery of hydrophobic bioactive compounds using curcumin as a model drug. As demonstrated by transmission electron microscopy and dynamic light scattering techniques, the HA-pNIPAM was simply assembled into spherical nano-sized particles with the thermoresponsive behavior. The success of curcumin aqueous solubilization was confirmed by fluorescent spectroscopy. The resulting nanogel formulation enhanced the aqueous solubility and uptake into NIH-3T3 cells of curcumin. This nanogel formulation also demonstrates cytocompatibility against NIH-3T3 cells, which deems it safe as a delivery vehicle. Moreover, the formulation has a slight skin-protection effect using an artificial skin equivalence model. The curcumin-loaded HA-pNIPAM nanogel showed an anti-proliferative activity against MDA-MB-231, Caco-2, HepG2, HT-29, and TNF-α-induced hyperproliferation of keratinocyte (HaCaT) cells. The thermoresponsive HA-pNIPAM nanogel reported here could be further optimized as a platform for controlled-release systems to encapsulate pharmaceuticals for therapeutic applications.