Injectable and Near-Infrared-Responsive Hydrogels Encapsulating Dopamine-Stabilized Gold Nanorods with Long Photothermal Activity Controlled for Tumor Therapy.

Gold nanorods (AuNRs) are confirmed to have excellent and repeated photothermal properties under near-infrared (NIR)-light irradiation above 780 nm. However, AuNRs easily leaked out from local pathological tissues and circulated in the body, reducing photothermal therapy (PTT) efficacy. By complexing AuNRs with a scaffold via interactions, AuNRs might be dispersed in the scaffold and fixed in the tumor site. Thus, based on the mussel-mimetic adhesion concept, AuNRs were designed to be coated with polydopamine (PDA), and then the prepared polydopamine-coated AuNRs (AuNR-PDA) were incorporated into a thermosensitive injectable hydrogel composed of ß-glycerophosphate-bound chitosan (CGP) and dopamine-modified alginate (Alg-DA) efficiently. Due to the strong interactions between PDA and polymers, AuNR-PDA could be immobilized stably and evenly into the obtained CGP/Alg-DA/AuNR composite hydrogel, which can avoid overheating locally or leaking out. The sol-gel transition temperature of the composite hydrogel was adjusted to the body temperature at around 37 °C to be conveniently injectable in vivo. With NIR irradiation at 808 nm of wavelength, the composite hydrogel was locally heated quickly to over 50 °C depending on controlling the irradiation powers and times. Moreover, the in vitro cytotoxicity test of the composite hydrogel showed good biocompatibility to normal cells but obvious suppression to tumor cells' growth under multiple times of photothermal therapy. Furthermore, the in vivo antitumor test demonstrated the obvious suppression to tumor growth of the CGP/Alg-DA/AuNR composite hydrogel under multiple PTTs. Therefore, the injectable CGP/Alg-DA/AuNR hydrogel could be a promising candidate for the long-term repeated photothermal treatment of tumors.

Platelet rich plasma combined with arthroscopic microfracture versus arthroscopic microfracture alone for the treatment of knee cartilage injury.

OBJECTIVE: To investigate the clinical efficacy of platelet-rich plasma (PRP) injection combined with arthroscopic microfracture technique in treating knee cartilage injury. METHODS: The clinical data of 120 patients with knee cartilage injuries treated in Jiangnan University Medical Center from October 2019 to December 2021 were analyzed retrospectively. Among them, 55 cases underwent the arthroscopic microfracture technique alone (control group), and the other 65 cases underwent PRP combined with the arthroscopic microfracture technique (observation group). The visual analogue scale (VAS) score, Lysholm knee joint score, MRI image indexes, the incidence of adverse events, and patient satisfaction during treatment were compared between groups before and after surgery. RESULTS: Before surgery and at 3, 6, and 12 months after surgery, VAS scores in both groups showed a decreasing trend with time (F = 40.780, P<0.001); VAS scores in the observation group were lower than those in the control group (F = 302.300, P<0.001); there was an interaction between grouping and time (F = 10.350, P<0.001); Lysholm score in both groups showed an increasing trend with time (F = 153.500, P<0.001); Lysholm scores in the observation group were higher than those in the control group (F = 488.000, P<0.001); there was an interaction between grouping and time (F = 25.570, P<0.001). At 12 months after surgery, the subchondral bone marrow oedema volumes and bone marrow defect areas in the observation group were smaller than those in the control group; while repaired cartilage thicknesses of the observation group were more significant than those of the control group (all P<0.05). Patient satisfaction in the observation group was higher than that the control group (95.38% VS 80%, P<0.05). There was no statistical difference in the incidence of adverse events between the control group and the observation group (7.27% VS 3.64%). The clinical efficacy was judged to be effective in 81 cases and markedly effective in 39 patients. Logistic regression analysis showed that age and body mass index (BMI) were independent factors affecting the treatment efficacy. CONCLUSION: PRP combined with the arthroscopic microfracture technique has high safety in treating knee cartilage injuries. Compared with the arthroscopic microfracture alone, PRP combined with arthroscopic microfracture technique can effectively relieve pain, promote the repair of defective cartilage, improve knee joint function, and increase patient satisfaction. It is worthy of clinical promotion.

RNA-Seq Reveals the mRNAs, miRNAs, and lncRNAs Expression Profile of Knee Joint Synovial Tissue in Osteoarthritis Patients.

Osteoarthritis (OA) is a chronic disease common in the elderly population and imposes significant health and economic burden. Total joint replacement is the only currently available treatment but does not prevent cartilage degeneration. The molecular mechanism of OA, especially the role of inflammation in disease progression, is incompletely understood. We collected knee joint synovial tissue samples of eight OA patients and two patients with popliteal cysts (controls), measured the expression levels of lncRNAs, miRNAs, and mRNAs in these tissues by RNA-seq, and identified differentially expressed genes (DEGs) and key pathways. In the OA group, 343 mRNAs, 270 lncRNAs, and 247 miRNAs were significantly upregulated, and 232 mRNAs, 109 lncRNAs, and 157 miRNAs were significantly downregulated. mRNAs potentially targeted by lncRNAs were predicted. Nineteen overlapped miRNAs were screened based on our sample data and GSE 143514 data. Pathway enrichment and functional annotation analyses showed that the inflammation-related transcripts CHST11, ALDH1A2, TREM1, IL-1ß, IL-8, CCL5, LIF, miR-146a-5p, miR-335-5p, lncRNA GAS5, LINC02288, and LOC101928134 were differentially expressed. In this study, inflammation-related DEGs and non-coding RNAs were identified in synovial samples, suggesting that competing endogenous RNAs have a role in OA. TREM1, LIF, miR146-5a, and GAS5 were identified to be OA-related genes and potential regulatory pathways. This research helps elucidate the pathogenesis of OA and identify novel therapeutic targets for this disorder.

Has_circ_0010220 regulates the miR-574-3p/IL-6 axis to increase doxorubicin resistance in osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common primary bone malignancy. It has an aggressive nature and produces drug resistance in diseased patients, which in turn causes obstacles in treating cancer with chemotherapy. The objective of our investigation was to analyze the function and hsa_circ_0010220 mechanism in doxorubicin (DOX) resistance to OS. METHODS: The hsa_circ_0010220, IL-6, and miR-574-3p levels in OS diseased tissues and cell resistance towards DOX drug were elucidated by qRT-PCR and Elisa assay. The DOX half-inhibitory concentration (IC50) was quantified by Cell Counting Kit-8. For this study, we used RNA pull-down, RNA immunoprecipitation, and a dual-luciferase reporter experiment to identify the proteins that interacted with has_circ_0010220, IL-6, and miR-574-3p in OS cells that have developed resistance towards DOX. RESULTS: The results indicated upregulated Hsa_circ_0010220 and IL-6 expression, However, DOX-resistant OS tissues and cells showed a downregulation of miR-574-3p. Reducing DOX resistance in vitro was achieved by silencing Has_circ_0010220. Further, by sponging miR-574-3p, increasing has_circ_0010220 boosted DOX resistance. However, miR-574-3p bound to IL-6 and inhibited DOX resistance. Additionally, it was discovered that hsa_circ_0010220 sponged miR-574-3p for upregulating IL-6 expression. CONCLUSIONS: Hsa_circ_0010220 encouraged OS resistance to DOX by miR-574-3p/IL-6 axis regulation, suggesting its potency as a promising biomarker for treating OS.

Long non-coding RNA ZNFX1 antisense 1 (ZFAS1) suppresses anti-oxidative stress in chondrocytes during osteoarthritis by sponging microRNA-1323.

LncRNAs play a regulatory role in osteoarthritis (OA); however, the detailed mechanism remains to be elucidated. This study aimed to investigate the role of lncRNA zinc finger NFX1-type containing 1 (ZNFX1) antisense 1 (ZFAS1) in OA progression and explore its possible mechanismsagainst oxidative stress. Human cartilage specimens were obtained from 10 patients without OA who underwent traumatic amputation and 25 patients with OA who underwent total knee replacement surgery. Chondrocytes were prepared from harvested articular cartilage. ZFAS1, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) expression levels were analyzed using quantitative reverse transcription PCR and WB. The chondrocyte growth was indicated by MTT and colony formation assays. Chondrocyte apoptosis, reactive oxygen species generation, and anti-oxidative enzymes activities were also measured. ZFAS1 expression was reduced in OA samples and lipopolysaccharide (LPS)-treated chondrocytes used as an OA cell model mimic. ZFAS1 overexpression facilitated proliferation and repressed oxidative stress, inflammation, and apoptosis in LPS-induced chondrocytes. ZFAS1 also activated the anti-oxidative Nrf2-HO-1 pathway. ZFAS1 directly targeted miR-1323, which partially reversed the effects of ZFAS1 on chondrocyte proliferation, oxidative stress, inflammation, and apoptosis. Furthermore, Nrf2 was negatively regulated by miR-1323. The effect of miR-1323 inhibition was partly abrogated by the administration of brusatol, an Nrf2 inhibitor. Collectively, the results showed that ZFAS1 promoted chondrocyte proliferation and repressed oxidative stress, possibly by regulating the novel miR-1323-Nrf2 axis of the inflammation and apoptosis triggered by LPS, indicating that ZFAS1 is a promising therapeutic target for OA.

Plasticity and Deformation Mechanisms of Ultrafine-Grained Ti in Necking Region Revealed by Digital Image Correlation Technique.

The conventional engineering stress-strain curve could not accurately describe the true stress-strain and local deformability of the necking part of tensile specimens, as it calculates the strain by using the whole gauge length, assuming the tensile specimen was deformed uniformly. In this study, we employed 3D optical measuring digital image correlation (DIC) to systematically measure the full strain field and local strain during the whole tensile process, and calculate the real-time strain and actual flow stress in the necking region of ultrafine-grained (UFG) Ti. The post-necking elongation and strain hardening exponent of the UFG Ti necking part were then measured as 36% and 0.101, slightly smaller than those of the coarse grained Ti (52% and 0.167), suggesting the high plastic deformability in the necking part of the UFG Ti. Finite elemental modeling (FEM) indicates that when necking occurs, strain is concentrated in the necking region. The stress state of the necking part was transformed from uniaxial in the uniform elongation stage to a triaxial stress state. A scanning electron microscopic (SEM) study revealed the shear and ductile fracture, as well as numerous micro shear bands in the UFG Ti, which are controlled by cooperative grain boundary sliding. Our work revealed the large plastic deformability of UFG metals in the necking region under a complex stress state.

PLEK2 promotes osteosarcoma tumorigenesis and metastasis by activating the PI3K/AKT signaling pathway.

Increasing evidence suggest that pleckstrin-2 (PLEK2) acts as an oncogene in several malignancies. The present study aimed to investigate the effects of PLEK2 on osteosarcoma (OS) tumorigenesis and metastasis. PLEK2 expression in OS was analyzed via bioinformatics, reverse transcription-quantitative PCR, western blot and immunohistochemistry analyses. The Cell Counting Kit-8 (CCK-8), colony formation and EdU assays were performed to assess the role of PLEK2 in OS cell proliferation. The pro-metastatic effects of PLEK2 were assessed via the Transwell and wound healing assays. In addition, the PLEK2 downstream pathway was analyzed via bioinformatics analysis and verified via western blot analysis. The results demonstrated that PLEK2 expression was upregulated in both OS cell lines and specimens. The results of the CCK-8, colony formation and EdU assays demonstrated that PLEK2 promoted OS cell proliferation in vitro. The in vivo experiments further demonstrated that PLEK2 knockdown significantly suppressed OS growth. In addition, the Transwell and wound healing assays indicated that PLEK2 promoted OS invasiveness in vitro, which was induced by the activation of the epithelial-to-mesenchymal transition process. Bioinformatics analysis revealed that PLEK2 can activate the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) pathway, which was verified via western blot analysis. Taken together, the results of the present study suggest that PLEK2 may play a tumor-promoting role in OS via the PI3K/AKT signaling pathway.

Treatment of meniscal injury: a current concept review.

Meniscal injury is one of the most common injuries to the knee. The menisci are important for normal knee function. And loss of a meniscus increases the risk of subsequent development of degenerative changes in the knee. Now there are different techniques available for meniscal injury. These techniques include expectant treatment, meniscectomy, meniscal repair, meniscal replacement, and meniscal tissue engineering. Expectant treatment is the appropriate treatment for minor tears of the menisci. Meniscectomy being favored at the beginning is now obsolete. Meniscus repair has become a standard procedure. Meniscal replacement and tissue engineering are used to deal with considerable meniscal injuries. The purpose of this paper is to provide current knowledge regarding the anatomy and function of the menisci, incidence, aetiology, symptoms, signs, investigations and treatments of meniscal injury.

Preparation and properties of dopamine-modified alginate/chitosan-hydroxyapatite scaffolds with gradient structure for bone tissue engineering.

Three-dimensional (3D) homogenous scaffolds composed of natural biopolymers have been reported as superior candidates for bone tissue engineering. There are still remaining challenges in fabricating the functional scaffolds with gradient structures to similar with natural bone tissues, as well as high mechanical properties and excellent affinity to surround tissues. Herein, inspired by the natural bone structure, a gradient-structural scaffold composed of functional biopolymers was designed to provide an optimized 3D environment for promoting cell growth. To increase the interactions among the scaffolds, dopamine (DA) was employed to modify alginate (Alg) and needle-like nano-hydroxyapatite (HA) was prepared with quaternized chitosan as template. The obtained dopamine-modified alginate (Alg-DA) and quaternized chitosan-templated hydroxyapatite (QCHA) were then used to fabricate the porous gradient scaffold by "iterative layering" freeze-drying technique with further crosslinking by calcium ions (Ca2+ ). The as-prepared Alg-DA/QCHA gradient scaffolds were possessed seamlessly integrated layer structures and high levels of porosity at around 77.5%. Moreover, the scaffolds showed higher compression modules (1.7 MPa) than many other biopolyermic scaffolds. The gradient scaffolds showed appropriate degradation rate to satisfy with the time of the bone regeneration. Both human chondrocytes and fibroblasts could adhesive and growth well on the scaffolds in vitro. Furthermore, an excellent osteogenetic activity of the gradient scaffold can effectively promote the regeneration of the bone tissue and accelerate the repair of the bone defects in vivo, compared with that of the scaffold with the homogenous structure. The novel multilayered scaffold with gradient structure provided an interesting option for bone tissue engineering. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1615-1627, 2019.

miR-195 inhibits the proliferation and migration of chondrocytes by targeting GIT1.

Previous studies have demonstrated that G-protein coupled receptor kinase interacting protein-1 (GIT1) and microRNAs (miRNAs) serve an important role in chondrocyte proliferation and migration. However, a limited number of studies conducted thus far have investigated the association between GIT1 and miRNAs. In the present study, putative miR­195 binding sites in the GIT1 3'­untranslated region were identified using common bioinformatic algorithms (miRanda, TargetScan, miRBase and miRWalk), and it was demonstrated that they may be involved in regulating GIT1 expression. Following transfection of miR­195 mimics in chondrocytes, the expression of GIT1 was significantly reduced, whereas the expression was significantly increased following transfection with miR­195 inhibitors. In addition, the results of the current study demonstrated that increased miR­195 expression may downregulate chondrocyte proliferation and reduce cell migration. However, chondrocyte proliferation and migration was enhanced following suppression of miR­195 expression. Furthermore, upon co­transfection of miR­195 and GIT1 expression vectors, the inhibitory effect of miR­195 on chondrocyte proliferation and migration was attenuated. Therefore, miR­195 may affect chondrocyte proliferation and migration via targeted regulation of GIT1 expression. The results of the current study provide novel evidence for the regulatory mechanisms of miRNAs in bone and cartilage tissues, which may facilitate further research and provide a greater understanding of different osteoarticular diseases.

miR-125a-3p targetedly regulates GIT1 expression to inhibit osteoblastic proliferation and differentiation.

Osteoblasts are a prerequisite for osteogenesis and bone formation, and play a key role in metabolic balance, growth, development and wound repair. G protein-coupled receptor kinase interacting protein 1 (GIT1) and a series of miRNAs are known to have important effects in the growth and migration of osteoblasts, but little is known about micro RNAs (miRNAs) targeting GIT1. The present study found that miR-125a-3p has matching sites on GIT1. In the osteoblastic differentiation process of human bone marrow-derived mesenchymal stem cells (HMSCs), the expression of miR-125a-3p was suppressed compared with that in non-differentiating (HMSCs) while the expression of GIT1 showed a gradual and significant increase. Thus, miR-125a-3p expression was negatively correlated with the expression of GIT1. Following the transfection of human osteoblasts with miR-125a-3p mimics and inhibitors, respectively, the effect on GIT1 expression was opposite to the change of miR-125a-3p expression. In addition, the impact of miR-125a-3p and GIT1 on osteoblastic proliferation and differentiation was detected, and the results indicated that miR-125a-3p targetedly regulated GIT1 expression to inhibit osteoblastic proliferation and differentiation. These findings may provide a theoretical basis for clarifying the physiological and pathological role of miRNAs in osteoblast differentiation and maturation processes, and for the physiological and pathological investigation of bone.

Restorative effect and mechanism of mecobalamin on sciatic nerve crush injury in mice.

Mecobalamin, a form of vitamin B12 containing a central metal element (cobalt), is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral nerves, but its molecular mechanism remains unclear. In the present study, we performed sciatic nerve crush injury in mice, followed by daily intraperitoneal administration of mecobalamin (65 µg/kg or 130 µg/kg) or saline (negative control). Walking track analysis, histomorphological examination, and quantitative real-time PCR showed that mecobalamin significantly improved functional recovery of the sciatic nerve, thickened the myelin sheath in myelinated nerve fibers, and increased the cross-sectional area of target muscle cells. Furthermore, mecobalamin upregulated mRNA expression of growth associated protein 43 in nerve tissue ipsilateral to the injury, and of neurotrophic factors (nerve growth factor, brain-derived nerve growth factor and ciliary neurotrophic factor) in the L4-6 dorsal root ganglia. Our findings indicate that the molecular mechanism underlying the therapeutic effect of mecobalamin after sciatic nerve injury involves the upregulation of multiple neurotrophic factor genes.

Chondrogenesis of myoblasts in biodegradable poly-lactide-co-glycolide scaffolds.

Myoblasts are considered to be an alternative cell source for cell-based meniscal repair due to their multiple differentiation potentials. This study addresses the chondrogenic differentiation of myoblasts seeded into poly-lactide-co-glycolide (PLGA) scaffolds following implantation in a subcutaneous pocket of nude mice. Canine myoblasts isolated from a Beagle were expanded and seeded into PLGA scaffolds and cultured in cartilage-derived morphogenetic protein-2 (CDMP-2) and transforming growth factor-ß1 (TGF-ß1)-containing medium for 2 weeks in vitro. The constructs were implanted into a subcutaneous pocket of 24 combined immunodeficiency mice and harvested after 8 and 12 weeks, respectively. Hematoxylin and eosin staining of the sections of the engineered cartilage at 8 and 12 weeks revealed the regeneration of fibrocartilage. Immunohistochemical staining confirmed a similar distribution of collagen type â…¡ in the engineered cartilage as the normal meniscus. At 12 weeks, expression of mRNAs for type â…  collagen, type â…¡ collagen and aggrecan was detected by RT-PCR. The compressive moduli of engineered cartilage reached 85.72% of the normal meniscus at 12 weeks, with a high level of glycosaminoglycan (GAG) content (no statistical difference from normal). Myoblast-seeded PLGA scaffolds express a stable chondrogenic phenotype in a heterotopic model of cartilage transplantation and represent a suitable tool for tissue engineering of cartilage.

Chondrogenic differentiation of canine myoblasts induced by cartilage-derived morphogenetic protein-2 and transforming growth factor-ß1 in vitro.

The meniscus has limited ability to repair itself following injury. However, tissue engineering provides new means of meniscus repair. Myoblasts, which possess the potential of multi-directional differentiation, may be ideal seed cells in meniscus tissue engineering. Myoblasts from different animals showed slight differences in morphology and in the potential to differentiate. In the present study, we isolated myoblasts from canines and induced chondrogenesis in order to establish a new experimental model of seed cells. Myoblasts were isolated and harvested from Beagle canines. To induce chondrogenesis, cartilage-derived morphogenetic protein-2 (CDMP-2) at different concentrations (10, 20, 50 and 100 ng/ml), transforming growth factor-ß1 (TGF-ß1; 10, 20, 30 and 50 ng/ml), and different concentrations of CDMP-2 (10, 20, 50 and 100 ng/ml) together with TGF-ß1 (20 ng/ml) were added to the cultured pellets. After 21 days of in vitro culture, chondrogenic differentiation was evaluated by histological and immunohistochemical techniques. The degree of gene expression was measured by quantitative RT-PCR. Based on the histological staining of glycosaminoglycan, using the toluidine blue dye-binding method, we found that CDMP-2 initiated chondrogenic differentiation of myoblasts, as did TGF-ß1. Furthermore, CDMP-2 conferred a stronger stimulatory effect than TGF-ß1. The combination of CDMP-2 and TGF-ß1 synergistically induced chondrogenesis of myoblasts. This synergistic chondrogenic effect of CDMP-2 together with TGF-ß1 was further confirmed by quantification of glycosaminoglycan using dimethylmethylene blue dye-binding assay and immunohistochemical analysis of the expression of cartilage-specific proteins collagen I and II. Canine myoblasts can be induced into chondrocytes by CDMP-2 and TGF-ß1 in vitro, suggesting that myoblasts are suitable as seed cells for meniscus tissue engineering.

Repair of meniscal defect using an induced myoblast-loaded polyglycolic acid mesh in a canine model.

Defects of the meniscus greatly alter knee function and predispose the joint to degenerative changes. The purpose of this study was to test a recently developed cell-scaffold combination for the repair of a critical-size defect in the canine medial meniscus. A bilateral, complete resection of the anterior horn of the medial meniscus was performed in 18 Beagle canines. A PLGA scaffold was implanted into the defect of one knee of 6 canines and the contralateral defect was left untreated. Scaffolds loaded with autologous myoblasts and cultured in a chondrogenic medium for 14 days were implanted in a second series of 12 canines. Empty scaffolds were implanted in the contralateral knees. Menisci were harvested at 12 weeks. Untreated defects had a muted fibrous healing response. Defects treated with cell-free implants also showed predominantly fibrous tissue, whereas fibrocartilage was present in several scaffolds. The thickness of the repair tissue after treatment with cell-free scaffolds was significantly greater compared to the controls (p<0.05). Pre-cultured implants integrated with the host tissue, and 9 of 12 contained meniscus-like fibrocartilage when compared to 2 of the 12 controls (p<0.05). The thickness of the pre-cultured implant repair tissue was greater compared to the controls (p<0.05). This study demonstrates the repair of a critical size meniscal defect using a stem cell and scaffold-based tissue engineering approach.