Mineralization, degradation and osteogenic property of polylactide multicomponent porous composites for bone repair: In vitro and in vivo study.

Gelatin and hydroxyapatite were assembled into polylactide porous matrix to prepare multicomponent porous composites for bone repair (PLA-gH). PLA-gH possessed a superior ability of mineralization. During simulated body fluids (SBF), the spherical Ca-P depositions on surface of PLA-gH became bulk as Ca/P decreased, while they locally turned into the rod with different variation in Ca/P during SBF containing bovine serum albumin (SBF-BSA), indicating that the mineralization of PLA-gH could be regulated by BSA. Meanwhile, PLA-gH possessed good degradation behaviour, especially in SBF-BSA, the degradation of PLA porous matrix was higher than that in SBF after 14-day immersion, whose crystallinity (Xc) decreased to a slightly lower level. Gelatin and hydroxyapatite endowed PLA-gH with good osteogenic property, characterized by obvious osteogenic differentiation and bone regeneration. In terms of predicting the cytocompatibility, osteogenic differentiation and new bone mineralization of PLA-gH by in vitro methods, applying SBF-BSA may be more reliable than SBF.

Hyaluronic Acid-Based Reactive Oxygen Species-Responsive Multifunctional Injectable Hydrogel Platform Accelerating Diabetic Wound Healing.

Diabetic wounds are more likely to develop into complex and severe chronic wounds. The objective of this study is to develop and assess a reactive oxygen species (ROS)-responsive multifunctional injectable hydrogel for the purpose of diabetic wound healing. A multifunctional hydrogel (HA@Cur@Ag) is successfully synthesized with dual antioxidant, antibacterial, and anti-inflammatory properties by crosslinking thiol hyaluronic acid (SH-HA) and disulfide-bonded hyperbranched polyethylene glycol (HB-PBHE) through Michael addition; while, incorporating curcumin liposomes and silver nanoparticles (AgNPs). The HA@Cur@Ag hydrogel exhibits favorable biocompatibility, degradability, and injectivity. The outcomes of in vitro and in vivo experiments demonstrate that the hydrogel can effectively be loaded with and release curcumin liposomes, as well as silver ions, thereby facilitating diabetic wound healing through multiple mechanisms, including ROS scavenging, bactericidal activity, anti-inflammatory effects, and the promotion of angiogenesis. Transcriptome sequencing reveals that the HA@Cur@Ag hydrogel effectively suppresses the activation of the tumour necrosis factor (TNF)/nuclear factor κB (NF-κB) pathway to ameliorate oxidative stress and inflammation in diabetic wounds. These findings suggest that this ROS-responsive multifunctional injectable hydrogel, which possesses the ability to precisely coordinate and integrate intricate biological and molecular processes involved in wound healing, exhibits notable potential for expediting diabetic wound healing.

Definition of follicular helper T cell and cytokines expression in synovial fluid of rheumatoid arthritis.

OBJECTIVE: This study aimed to assess the role of synovial fluid (SF) CD4+T, CD19+B, follicular helper cells (Tfh), and cytokines in the pathogenesis of rheumatoid arthritis (RA). METHODS: This study enrolled 16 patients with RA and 8 patients with osteoarthritis (OA). The frequencies of the SF CD4+ T, CD19+ B, Tfh cells, and Tfh subsets were assessed using flow cytometry. The medical condition in patients with RA was evaluated using The Disease Activity Score 28 (DAS28), the Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI). Levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), anti-cyclic citrullinated peptide (anti-CCP), and rheumatoid factor (RF) were measured. The cytokines IL-4, IL-13, IL-21, and BLyS were measured by ELISA test. RESULTS: The percentages of SF CD4+T, CD19+B, and PD-1+CXCR5+ Tfh in RA patients were higher than those in OA patients. And the Tfh2 was the main subset among Tfh subsets. In addition, levels of IL-21 and BLyS were higher in patients with RA compared to patients with OA. Furthermore, the treatment of TNF-α inhibitors may be associated with decreased levels of SF Tfh. CONCLUSIONS: Elevated SF Tfh, B cell, and cytokines expression profiles were observed in RA patients. Tfh2 was the major subset of the Tfh, and IL-21 and BLyS were significantly enhanced. Additionally, TNF-α inhibitors reduced Tfh in SF. Therefore, Tfh, B, and Tfh2 cells could play a significant role in the progression of RA. Key Points •Tfh cells in the synovial fluid are significantly higher in RA patients and are dominated by the Tfh2 subpopulation. •Synovial fluid Tfh cells decrease in RA patients after anti-TNF-α treatment.

Multifunctional Injectable Hydrogel Microparticles Loaded with miR-29a Abundant BMSCs Derived Exosomes Enhanced Bone Regeneration by Regulating Osteogenesis and Angiogenesis.

The study investigated whether both the osteogenic and angiogenic potential of Exos (Exosomes) can be enhanced by overexpression of exosomal miRNA (microRNA) and to confirm whether Exos loaded in HMPs (Hydrogel microparticles) exert long-term effects during new bone formation. BMSCs and Exos are successfully obtained. In vitro and in vivo experiments confirmed that HDAC4 (Histone deacetylase 4) is inhibited by miR-29a overexpression accompanied by the upregulation of RUNX2 (Runt-related transcription factor 2) and VEGF (Vascular Endothelial Growth Factor), thereby enhancing osteogenic and angiogenic capabilities. The HMP@Exo system is synthesized from HB-PEGDA (Hyperbranched Poly Ethylene Glycol Diacrylate)- and SH-HA (Sulfhydryl-Modified Hyaluronic Acid)-containing Exos using a microfluidic technique. The HMP surface is modified with RGD (Arg-Gly-Asp) peptides to enhance cell adhesion. The system demonstrated good injectability, remarkable compatibility, outstanding cell adhesion properties, and slow degradation capacity, and the sustained release of Agomir-29a-Exos (Exosomes derived from Agomir-29a transfected BMSCs) from HMPs enhanced the proliferation and migration of BMSCs and HUVECs (Human Umbilical Vein Endothelial Cells) while promoting osteogenesis and angiogenesis. Overall, the findings demonstrate that the HMP@Exo system can effectively maintain the activity and half-life of Exos, accompanied by overexpression of miR-29a (microRNA-29a). The injectable system provides an innovative approach for accelerating fracture healing by coupling osteogenesis and angiogenesis.

Injectable hyperbranched PEG crosslinked hyaluronan hydrogel microparticles containing mir-99a-3p modified subcutaneous ADSCs-derived exosomes was beneficial for long-term treatment of osteoarthritis.

Exosomes (Exos) secreted by adipose-derived stem cells (ADSCs) have shown potential in alleviating osteoarthritis (OA). Previous studies indicated that infrapatellar fat pad (IPFP) derived stem cells (IPFSCs) may be more suitable for the treatment of OA than subcutaneous adipose tissue (ScAT) derived stem cells (ScASCs). However, it remains unclear which type of Exos offers superior therapeutic benefit for OA. This study first compared the differences between Exos derived from IPFP stem cells (ExosIPFP) and ScAT stem cells (ExosScAT) in OA treatment. Results suggested that ExosIPFP significantly inhibit the degradation of cartilage extracellular matrix (ECM) than ExosScAT, following this, the differences in microRNA (miRNA) expression between the two types of Exos using small RNA sequencing were performed. Subsequently, miR-99 b-3p was chosen and over-expressed in ExosScAT (ExosScAT-99b-3p), both in vivo and in vitro experiments demonstrated its efficacy in inhibiting the expression of ADAMTS4, promoting the repair of the ECM in OA. Finally, microfluidic technology was performed to fabricate a hyaluronan-based hydrogel microparticles (HMPs) for encapsulating Exos (HMPs@exos), the injectability, sustained release of Exos and long-term therapeutic effect on OA were validated. In summary, these results suggest miR-99 b-3p regulates the degradation of cartilage ECM by targeting ADAMTS4, the upregulation of miR-99 b-3p in ExosScAT would enable them to exhibit comparable or even superior effectiveness to ExosIPFP for OA treatment, making it a promising approach for OA treatment. Considering the abundant resources of ScAT and the limited availability of IPFP, ScAT harvested through liposuction could be genetically engineered to yield Exos for OA treatment. Furthermore, the encapsulation of Exos in HMPs provides an injectable sustained local drug release system, which could potentially enhance the efficacy of Exos and hold potential as future therapeutic strategies.

Rapid On-site identification of geographical origin and storage age of tangerine peel by Near-infrared spectroscopy.

The feasibility of identifying geographical origin and storage age of tangerine peel was explored by using a handheld near-infrared (NIR) spectrometer combined with machine learning. A handheld NIR spectrometer (900-1700 nm) was used to scan the outer surface of tangerine peel and collect the corresponding NIR diffuse reflectance spectra. Principal component analysis (PCA) combined with Mahalanobis distance were used to detect outliers. The accuracies of all models in the anomaly set were much lower than that in calibration set and test set, indicating that the outliers were effectively identified. After removing the outliers, in order to initially explore the clustering characteristics of tangerine peels, PCA was performed on tangerine peels from different origins and the same origin with different storage ages. The results showed that the tangerine peels from the same origin or the same storage age had the potential to cluster, indicating that the spectral data of the same origin or the same storage age had a certain similarity, which laid the foundation for subsequent modeling and identification. However, there were quite a few samples with different origins or different storage ages overlapped and could not be distinguished from each other. In order to achieve qualitative identification of origin and storage age, Savitzky-Golay convolution smoothing with first derivative (SGFD) and standard normal variate (SNV) were used to preprocess the raw spectra. Random forest (RF), K-nearest neighbor (KNN) and linear discriminant analysis (LDA) were used to establish the discriminant model. The results showed that SGFD-LDA could accurately distinguish the origin and storage age of tangerine peel at the same time. The origin identification accuracy was 96.99%. The storage age identification accuracy was 100% for Guangdong tangerine peel and 97.15% for Sichuan tangerine peel. This indicated that the near-infrared spectroscopy (NIRS) combine with machine learning can simultaneously and rapidly identify the origin and storage age of tangerine peel on site.

L-Carnitine ameliorates congenital myopathy in a tropomyosin 3 de novo mutation transgenic zebrafish.

BACKGROUND: Congenital myopathy (CM) is a group of clinically and genetically heterogeneous muscle disorders, characterized by muscle weakness and hypotonia from birth. Currently, no definite treatment exists for CM. A de novo mutation in Tropomyosin 3-TPM3(E151G) was identified from a boy diagnosed with CM, previously TPM3(E151A) was reported to cause CM. However, the role of TPM3(E151G) in CM is unknown. METHODS: Histopathological, swimming behavior, and muscle endurance were monitored in TPM3 wild-type and mutant transgenic fish, modelling CM. Gene expression profiling of muscle of the transgenic fish were studied through RNAseq, and mitochondria respiration was investigated. RESULTS: While TPM3(WT) and TPM3(E151A) fish show normal appearance, amazingly a few TPM3(E151G) fish display either no tail, a crooked body in both F0 and F1 adults. Using histochemical staining for the muscle biopsy, we found TPM3(E151G) displays congenital fiber type disproportion and TPM3(E151A) resembles nemaline myopathy. TPM3(E151G) transgenic fish dramatically swimming slower than those in TPM3(WT) and TPM3(E151A) fish measured by DanioVision and T-maze, and exhibit weaker muscle endurance by swimming tunnel instrument. Interestingly, L-carnitine treatment on TPM3(E151G) transgenic larvae significantly improves the muscle endurance by restoring the basal respiration and ATP levels in mitochondria. With RNAseq transcriptomic analysis of the expression profiling from the muscle specimens, it surprisingly discloses large downregulation of genes involved in pathways of sodium, potassium, and calcium channels, which can be rescued by L-carnitine treatment, fatty acid metabolism was differentially dysregulated in TPM3(E151G) fish and rescued by L-carnitine treatment. CONCLUSIONS: These results demonstrate that TPM3(E151G) and TPM3(E151A) exhibit different pathogenicity, also have distinct gene regulatory profiles but the ion channels were downregulated in both mutants, and provides a potential mechanism of action of TPM3 pathophysiology. Our results shed a new light in the future development of potential treatment for TPM3-related CM.

Discovery in CRISPR-Cas9 system. / CRISPR-Cas9系统的发现.

The 2020 Nobel Prize in Chemistry was awarded to the American scientist Jennifer A. Doudna and the French scientist Emmanuelle Charpentier, in recognition of their discovery in one of the greatest weapons in genetic technology: CRISPR-Cas9 gene scissors. The CRISPR-Cas system is a bacterial defense immune system against exogenous genetic material. Because the system can specifically recognize and cut DNA, this technology is widely used for precise editing of animal, plant, and microbial DNA. The discovery of CRISPR-Cas9 gene scissors enables the tedious and complicated cell gene editing work to be completed in a few weeks or even less, which has promoted the development of gene editing technology in various fields and brought revolutionary influence to the field of life sciences. At the same time, CRISPR gene editing technology has become one of the new therapies for tumors because of its large number of targets and relatively simple operation, and it also makes gene therapy possible. Although the technology still needs to solve technical problems such as off-target and promoter inefficiency, the CRISPR-Cas system will show its unique advantages in more fields with the continuous development of life science and basic medicine.