Medical sealant devices for in vivo hemostasis are far from satisfactory in the aged society. A major challenge is effective integration of quick hemorrhage control of the increased anticoagulated ...patients, high safety, and facile accessibility. Here, a well‐defined ammonolysis‐based Tetra‐PEG hydrogel sealant is developed with rapid gelation speed, strong tissue adhesion, and high mechanical strength. Introduction of cyclized succinyl ester groups into a hydrogel matrix endows the sealant with fast degradable and controllably dissolvable properties. The hydrogel possesses outstanding hemostatic capabilities even under the anticoagulated conditions while displaying excellent biocompatibility and feasibility. These results reveal that the optimized hydrogel may be a facile, effective, and safe sealant for hemorrhage control in vivo.
A PEG sealant with fast and controllable degradation properties is constructed for in vivo visceral organ hemostasis, which possesses high hemostatic efficacy even under anticoagulated situations and which, even more remarkably, does not hinder the tissue healing and cause side effects.
Abstract Background Hip fractures are always associated with a high postoperative mortality, the preoperative predictors for mortality have neither been well identified or summarised. This systematic ...review and meta-analysis was performed to identify the preoperative non-interventional predictors for mortality in hip fracture patients, especially focused on 1 year mortality. Methods Non-interventional studies were searched in Pubmed, Embase, Cochrane central database (all to February 26th, 2011). Only prospective studies and retrospective studies with prospective collected data were included. Qualities of included studies were assessed by a standardised scale previous reported for observational studies. The effects of individual studies were combined with the study quality score using a previous reported model of best-evidence synthesis. The hazard ratios of strong evidence predictors were combined only by high quality studies. Results 75 included studies with 94 publications involving 64,316 patients were included and the available observations was a heterogeneous group. The overall inpatient or 1 month mortality was 13.3%, 3–6 months was 15.8%, 1 year 24.5% and 2 years 34.5%. There were strong evidence for 12 predictors, including advanced age, male gender, nursing home or facility residence, poor preoperative walking capacity, poor activities of daily living, higher ASA grading, poor mental state, multiple comorbidities, dementia or cognitive impairment, diabetes, cancer and cardiac disease. We also identified 7 moderate evidence and 12 limited evidence mortality predictors, and only the race was identified as the conflicting evidence predictor. Conclusion Whilst there is no conclusive evidence of the preoperative predictors for mortality following hip fractures, special attention should be paid to the above 12 strong evidence predictors. Future researches were still needed to evaluate the effects of these predictors.
Osteoclasts are the exclusive cells of bone resorption. Abnormally activating osteoclasts can lead to low bone mineral density, which will cause osteopenia, osteoporosis, and other bone disorders. To ...date, the mechanism of how osteoclast precursors differentiate into mature osteoclasts remains elusive. MicroRNAs (miRNAs) are novel regulatory factors that play an important role in numerous cellular processes, including cell differentiation and apoptosis, by post-transcriptional regulation of genes. Recently, a number of studies have revealed that miRNAs participate in bone homeostasis, including osteoclastic bone resorption, which sheds light on the mechanisms underlying osteoclast differentiation. In this review, we highlight the miRNAs involved in regulating osteoclast differentiation and bone resorption, and their roles in osteoporosis.
Tissue engineering is a promising strategy for the repair and regeneration of damaged tissues or organs. Biomaterials are one of the most important components in tissue engineering. Recently, ...magnetic hydrogels, which are fabricated using iron oxide-based particles and different types of hydrogel matrices, are becoming more and more attractive in biomedical applications by taking advantage of their biocompatibility, controlled architectures, and smart response to magnetic field remotely. In this literature review, the aim is to summarize the current development of magnetically sensitive smart hydrogels in tissue engineering, which is of great importance but has not yet been comprehensively viewed.
Osteoarthritis (OA) is a major disease that causes disability in middle-aged and elderly people. A comprehensive understanding of its pathogenesis is of great significance in finding new clinical ...diagnosis and treatment schemes. The role of Semaphorin 3A (Sema3A) in OS has attracted attention recently, and the purpose of this study is to analyze the mechanisms underlying its impact on OS. First, a rat model of OS was established. Hematoxylin-eosin (HE) and TUNEL staining showed that the modeled rats presented typical pathological manifestations of OS, confirming the success of the modeling. Sema3A was significantly underexpressed in OS rats. Subsequently, Sema3A abnormal expression vectors were constructed to intervene in chondrocytes isolated from OS rats. It was found that the proliferation of chondrocytes was decreased, the apoptosis was increased, and the mitochondrial damage and autophagy were intensified after silencing Sema3A expression, while the above pathological processes were reversed when Sema3A expression was increased. In conclusion, Sema3A has an important influence on the pathological progression of OS, and molecular therapies targeting to increase Sema3A expression may become a new treatment for OS in the future.
Mesenchymal stem cell (MSC) is an absorbing candidate for cell therapy in treating spinal cord injury (SCI) due to its great potential for multiple cell differentiation, mighty paracrine secretion as ...well as vigorous immunomodulatory effect, of which are beneficial to the improvement of functional recovery post SCI. However, the therapeutic effects of MSC on SCI have been limited because of the gradual loss of MSC stemness in the process of expanding culture. Therefore, in this study, we aimed to maintain those beneficial properties of MSC via three-dimensional spheroid cell culture and then compared them with conventionally-cultured MSCs in the treatment of SCI both in vitro and in vivo with the aid of two-photon microscope. We found that 3D human placenta-derived MSCs (3D-HPMSCs) demonstrated a significant increase in secretion of anti-inflammatory factors and trophic factors like VEGF, PDGF, FGF via QPCR and Bio-Plex assays, and showed great potentials on angiogenesis and neurite morphogenesis when co-cultured with HUVECs or DRGs in vitro. After transplantation into the injured spinal cord, 3D-HPMSCs managed to survive for the entire experiment and retained their advantageous properties in secretion, and exhibited remarkable effects on neuroprotection by minimizing the lesion cavity, inhibiting the inflammation and astrogliosis, and promoting angiogenesis. Further investigation of axonal dieback via two-photon microscope indicated that 3D-HPMSCs could effectively alleviate axonal dieback post injury. Further, mice only treated with 3D-HPMSCs obtained substantial improvement of functional recovery on electrophysiology, BMS score, and Catwalk analysis. RNA sequencing suggested that the 3D-HPMSCs structure organization-related gene was significantly changed, which was likely to potentiate the angiogenesis and inflammation regulation after SCI. These results suggest that 3D-HPMSCs may hold great potential for the treatment of SCI.
Persisted myelin debris inhibit axon regeneration and contribute to further tissue damage after spinal cord injury (SCI). The traditional view is that myelin debris is mainly cleared by microglia and ...macrophages, while astrocytes cannot directly engulf myelin debris because they are absent from lesion core. Here, we definitely showed that astrocytes could directly uptake myelin debris both in vitro and in vivo to effectively complement the clearance function. Therefore, it can be shown that astrocytes can exert myelin clearance effect directly and indirectly after spinal cord injury. The damaged myelin debris was transported to lysosomes for degradation through endocytosis pathways, finally resulting in excessive gliosis. This process may be a potential target for regulating neural tissue repair and excessive glia scar formation after SCI.
•Insufficient myelin debris clearance after SCI.•Astrocytes directly clear myelin debris.•Myelin debris was transported to lysosomes degradation through endocytosis.
The dorsal root ganglia (DRG) contain the somas of first-order sensory neurons critical for somatosensation. Due to technical difficulties, DRG neuronal activity in awake behaving animals remains ...unknown. Here, we develop a method for imaging DRG at cellular and subcellular resolution over weeks in awake mice. The method involves the installation of an intervertebral fusion mount to reduce spinal movement, and the implantation of a vertebral glass window without interfering animals' motor and sensory functions. In vivo two-photon calcium imaging shows that DRG neuronal activity is higher in awake than anesthetized animals. Immediately after plantar formalin injection, DRG neuronal activity increases substantially and this activity upsurge correlates with animals' phasic pain behavior. Repeated imaging of DRG over 5 weeks after formalin injection reveals persistent neuronal hyperactivity associated with ongoing pain. The method described here provides an important means for in vivo studies of DRG functions in sensory perception and disorders.
1,4,5 This may be because of a lack of understanding of the morphological changes that take place in the proximal humerus at different ages. ...in this study, we analyzed and compared the anatomical ...degeneration pattern of the medullary canal between older and younger patients to have a better understanding of the medullary morphology of proximal humerus anatomically and the application of endosteal support clinically. ...the section of the medullary canal at the level of the SP was calibrated, the best fitting circle of the section was obtained using the automatic fitting arc function of 3-matic software, and the diameter (Ds) of the circle was measured Figure 1F. ...in older patients, expansion of the proximal humeral medullary cavity renders the medullary cavity irregular, which does not anatomically match with the shape of the existing nails or struts Figure 1G. ...a more effective anatomical supporting augment is needed for the treatment of older patients. ...compared with younger patients, the medullary canal of the proximal humerus expanded significantly, especially the medial offset, showing an “eggshell”-like cavity structure in older patients.
Angiogenesis and osteogenesis are coupled. However, the cellular and molecular regulation of these processes remains to be further investigated. Both tissues have recently been recognized as ...endocrine organs, which has stimulated research interest in the screening and functional identification of novel paracrine factors from both tissues. This review aims to elaborate on the novelty and significance of endocrine regulatory loops between bone and the vasculature. In addition, research progress related to the bone vasculature, vessel-related skeletal diseases, pathological conditions, and angiogenesis-targeted therapeutic strategies are also summarized. With respect to future perspectives, new techniques such as single-cell sequencing, which can be used to show the cellular diversity and plasticity of both tissues, are facilitating progress in this field. Moreover, extracellular vesicle-mediated nuclear acid communication deserves further investigation. In conclusion, a deeper understanding of the cellular and molecular regulation of angiogenesis and osteogenesis coupling may offer an opportunity to identify new therapeutic targets.
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