BACKGROUND:As tissue engineering brings new hope to the worldwide problem of articular cartilage repair,the construction of light-curing 3D printed hydrogel scaffolds with biomimetic composition is of great significance for cartilage tissue engineering. OBJECTIVE:To construct a biomimetic methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold by digital light processing 3D printing technology,and to evaluate its biocompatibility. METHODS:Wharton's jelly was isolated and extracted from human umbilical cord,then decellulated,freeze-dried,ground into powder,and dissolved in PBS to prepare 50 g/L acellular Wharton's jelly solution.Methylallylated hyaluronic acid was prepared,lyophilized and dissolved in PBS to prepare 50 g/L methylallylated hyaluronic acid solution.Acellular Wharton's jelly solution was mixed with methacrylyacylated hyaluronic acid solution at a volume ratio of 1:1,and was used as bio-ink after adding photoinitiator.Methylacrylylated hyaluronic acid hydrogel scaffolds(labeled as HAMA hydrogel scaffolds)and methylacrylylated hyaluronic acid/acellular Wharton's jelly gel scaffolds(labeled as HAMA/WJ hydrogel scaffolds)were prepared by digital light processing 3D printing technology,and the microstructure,swelling performance,biocompatibility,and cartilage differentiation performance of the scaffolds were characterized. RESULTS AND CONCLUSION:(1)Under scanning electron microscope,the two groups of scaffolds showed a three-dimensional network structure,and the fiber connection of HAMA/WJ hydrogel scaffold was more uniform.Both groups achieved swelling equilibrium within 10 hours,and the equilibrium swelling ratio of HAMA/WJ hydrogel scaffold was lower than that of HAMA hydrogel scaffold(P＜0.05).(2)CCK-8 assay showed that HAMA/WJ hydrogel scaffold could promote the proliferation of bone marrow mesenchymal stem cells compared with HAMA hydrogel scaffold.Dead/live staining showed that bone marrow mesenchymal stem cells grew well on the two groups of scaffolds,and the cells on the HAMA/WJ hydrogel scaffolds were evenly distributed and more cells were found.Phalloidine staining showed better adhesion and spread of bone marrow mesenchymal stem cells in HAMA/WJ hydrogel scaffold than in HAMA.(3)Bone marrow mesenchymal stem cells were inoculated into the two groups for chondrogenic induction culture.The results of qRT-PCR showed that the mRNA expressions of agglutinoglycan,SOX9 and type Ⅱ collagen in the HAMA/WJ hydrogel scaffold group were higher than those in the HAMA hydrogel scaffold group(P＜0.05,P＜0.01).(4)These findings indicate that the digital light processing 3D bioprinting HAMA/WJ hydrogel scaffold can promote the proliferation,adhesion,and chondrogenic differentiation of bone marrow mesenchymal stem cells.

Objective To observe the effects of Daizong Prescription on glycogen metabolism in adipose tissue of obese mice;To explore its regulatory mechanism in activating browning in the white adipose tissue.Methods A obesity model was established by feeding high-fat diet to C57BL/6J mice.The obese mice were divided into model group,metformin group(0.15 g/kg),and Daizong Prescription low-(0.20 g/kg)and high-dosage(0.40 g/kg)groups.Mice fed a standard diet were set as the normal group,with 12 mice in each group.Each medication group was given corresponding drugs by gavage for 6 consecutive weeks.Body mass and fasting blood glucose were monitored,serum triglycerides(TG),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)contents were measured.Brown adipose tissue from the interscapular region and white adipose tissue from the inguinal,perirenal and epididymal region were collected,the adipose tissue mass was measured,and the body fat coefficient was calculated.HE staining was performed to observe morphological changes in adipose tissue,PAS staining was used to observe glycogen distribution in adipose tissue,immunohistochemistry staining was performed to detect the expressions of Gys2,Ppp1r3c,and GSK-3β in inguinal white adipose tissue.Results Compared with the normal group,the body mass and fasting blood glucose in different time points of the model group significant increase(P<0.05,P<0.01),and serum TC and HDL-C contents significantly increased(P<0.01);the mass and body fat coefficient of white adipose tissue in inguinal,perirenal,and epididymis significantly increased(P<0.01),the cells in white adipose tissue in inguinal were hypertrophic and appeared as large vacuoles,with less glycogen accumulation,the expressions of Gys2 and Ppp1r3c significantly decreased(P<0.01).Compared with the model group,the mice in Daizong Prescription high-dosage group showed a significant decrease in body mass and fasting blood glucose at 4 and 6 weeks of administration(P<0.05,P<0.01),and the contents of serum TG,TC,HDL-C,and LDL-C were significantly decreased(P<0.01);the mass and body fat coefficient in white adipose tissue of perirenal and epididymal significantly decreased(P<0.05,P<0.01),and the mass of inguinal white adipose tissue significantly decreased(P<0.05),multiple irregularly shaped small vacuoles could be seen in inguinal white adipose tissue,accompanied by nuclear aggregation and increased glycogen accumulation,the expressions of Gys2 and Ppp1r3c significantly increased(P<0.01).There was no significant difference in the expression of GSK-3β inguinal white adipose tissue of mice among the groups.Conclusion Daizong Prescription can increase the activity of Gys2 by upregulating the expression of Ppp1r3c,promote glycogen synthesis,induce browning of adipose tissue,increase fat heat production,and improve obesity and related disorders of glycolipid metabolism.

Humans ; Consensus ; Pancreatic Neoplasms/therapy* ; Neuroendocrine Tumors/therapy*

Group A Streptococcus (GAS) is a very important pathogen, especially for children.On a global scale, GAS is an important cause of morbidity and mortality.But the burden of disease caused by GAS is still unknown in China and also has not obtained enough attention.For this purpose, the expert consensus is comprehensively described in diagnosis, treatment and prevention of GAS diseases in children, covering related aspects of pneumology, infectiology, immunology, microbiology, cardiology, nephrology, critical care medicine and preventive medicine.Accordingly, the consensus document was intended to improve management strategies of GAS disease in Chinese children.

BACKGROUND: With the development of cartilage tissue engineering, affinity peptides have attracted some attention because of their special affinity to some key factors of cartilage tissue engineering. OBJECTIVE: To review the screening and identification of various affinity peptides and their application in cartilage tissue engineering. METHODS: The articles related to affinity peptides in CNKI, Wanfang, and PubMed were searched by computer from January 2000 to May 2020. “Affinity peptides, cartilage tissue engineering, mesenchymal stem cell, scaffold” in English and Chinese were used as key words. Finally, 66 articles were included for analysis. RESULTS AND CONCLUSION: Many polypeptides with specific amino acid sequence can bind with some cells, factors and molecules, and have affinity. According to different targets, they can be divided into cell affinity peptide, factor affinity peptide and extracellular matrix molecular affinity peptide. Affinity peptides have been used in cartilage tissue engineering through screening and identification to enhance the repair effect of tissue engineering by adhering fine cells, recruitment factors and molecules. In many strategies of biomimetic cartilage multilayer scaffolds, affinity peptides that interact with specific molecules play an important role in simulating the environment of normal cartilage. At the same time, with the development of cartilage tissue engineering technology, especially the application of computer-aided technology, it provides a new strategy for the use of affinity peptides. However, the residence time, degradation rate and degradation pathway of affinity peptides in vivo are relatively few, which need to be further understood.

Due to good mechanical properties and biocompatibility, tissue engineering scaffolds have become the vital method for repairing and regenerating articular cartilage defects. With the continuous development of tissue engineering technology, many scaffolds preparation and formation methods have been developed and tested in the past decade, however, the preparation of ideal regenerative scaffolds remain controversial. As load-bearing tissue inside the body joints, the matrix structure and cell composition of articular cartilage are hierarchical, and there are several smooth natural gradients from the cartilage surface to the subchondral bone layer, including cell phenotype and number, specific growth factors, matrix composition, fiber arrangement, mechanical properties, nutrient and oxygen consumption. Therefore, in the design of regenerative scaffolds, it is necessary to achieve these gradients to regenerate articular cartilage in situ. In recent studies, many new biomimetic gradient scaffolds have been used to simulate the natural gradient of articular cartilage. These scaffolds show different mechanical, physicochemical or biological gradients in the structure, and have achieved good repair effects. The related articles on tissue engineering for the treatment of articular cartilage defects were retrieved by searching databases with key wordsarticular cartilage injury, cartilage repair and gradient scaffolds. In this work,the structural, biochemical, biomechanical and nutrient metabolism gradients of natural articular cartilage were studied and summarized firstly. Then, the latest design and construction of articular cartilage gradient scaffolds were classified. Besides that, the material composition (such as hydrogels, nanomaterials, etc.) and the preparation process (such as electrospinning, 3D printing, etc.) of grandient scaffolds were further enhanced. Finally, the prospect and challenge of biomimetic gradient scaffolds in cartilage engineering are discussed, which provides a theoretical basis for the successful application of gradient scaffolds in clinical transformation.

OBJECTIVE: Bufalin is an effective drug for the treatment of liver cancer. But its high toxicity, poor water-solubility, fast metabolism and short elimination half-life limit its use in tumor treatment. How to make the drug accumulate in the tumor and reduce side effects while maintaining its efficacy are urgent problems to be solved. The goal of this study is to solve these problems. METHODS: A copolymer with tunable poly-N-isopropylacrylamide and polylactic acid was designed and synthesized. The corresponding dual targeting immunomicelles (DTIs) loaded with bufalin (DTIs-BF) were synthesized by copolymer self-assembly in an aqueous solution. The size and structure of DTIs-BF were determined by ZetaSizer Nano-ZS and transmission electron microscopy. Then, its temperature sensitivity, serum stability, critical micelle concentration (CMC), entrapment efficiency (EE), drug release and non-cytotoxicity of blank block copolymer micelles (BCMs) were evaluated. Next, the effects of DTIs-BF on cellular uptake, cytotoxicity, and tumor cell inhibition were evaluated. Finally, the accumulation of DTIs-fluorescein isothiocyanate (FITC) and the in vivo anti-tumor effect were observed using an interactive video information system. RESULTS: DTIs-BF had a small size, spherical shape, good temperature sensitivity, high serum stability, low CMC, high EE, and slow drug release. The blank BCMs had very low cytotoxicity. Compared with free bufalin, the in vitro cellular internalization and cytotoxicity of DTIs-BF against SMMC-7721 cells were significantly enhanced, and the effects were obviously better at 40 °C than 37 °C. In addition, the therapeutic effect on SMMC-7721 cells was further enhanced by the programmed cell death specifically caused by bufalin. When DTIs-FITC were injected intravenously in BALB/c nude mice bearing liver cancer, the accumulation of FITC was significantly increased in tumors. CONCLUSION DTIs-BF is a potentially effective nano-formulation and has broad prospects in the clinical treatment of liver cancer.
Animals ; Antineoplastic Agents/pharmacology* ; Bufanolides ; Cell Line, Tumor ; Liver Neoplasms/drug therapy* ; Mice ; Mice, Inbred BALB C ; Mice, Nude

The treatment of articular cartilage (AC) injury caused by various reasons is still a major clinical problem. The emergence of cartilage tissue engineering brings new hope for the treatment of AC injury. In general, AC tissue engineering can be divided into two categories, including cell-based tissue engineering and cell-free tissue engineering. Although cell-based tissue engineering can repair cartilage damage to a certain extent, existing therapeutic strategies still suffer from limited cell sources, high costs, risk of disease transmission, and complex procedures. However, the cell-free tissue engineering avoids these shortcomings and brings hope for in-situ AC regeneration. Non-cellular tissue engineering is mainly used to recruit endogenous stem cells/progenitor cells (SCPCs) to reach the site of cartilage injury, and provide a suitable regenerative microenvironment to promote cell proliferation and chondrogenic differentiation, then the maturation of new cartilage tissue was promoted. Therefore, it is also called as cell-homing in situ tissue engineering. Successful recruitment of endogenous SCPCs is the first step in in-situ cartilage tissue engineering. This review aims to introduce chemokine response of cartilage injury, systematically summarize traditional chemoattractant (chemokines and growth factors etc.) and emerging chemoattractant (functional peptides, exosomes and nucleic acid adapters etc.), evaluate the combination mode between chemoattractant and delivery devices, discuss the prospects and challenges of chemoattractant-mediated in situ tissue engineering and provide theoretical basis for the design of endogenous SCPCs homing-based in situ tissue engineering.

Once pulp necrosis or apical periodontitis occurs on immature teeth, the weak root and open root apex are challenging to clinicians. Berberine (BBR) is a potential medicine for bone disorders, therefore, we proposed to apply BBR in root canals to enhance root repair in immature teeth. An in vivo model of immature teeth with apical periodontitis was established in rats, and root canals were filled with BBR, calcium hydroxide or sterilized saline for 3 weeks. The shape of the roots was analyzed by micro-computed tomography and histological staining. In vitro, BBR was introduced into stem cells from apical papilla (SCAPs). Osteogenic differentiation of stem cells from apical papilla was investigated by alkaline phosphatase activity, mineralization ability, and gene expression of osteogenic makers. The signaling pathway, which regulated the osteogenesis of SCAPs was evaluated by quantitative real time PCR, Western blot analysis, and immunofluorescence. In rats treated with BBR, more tissue was formed, with longer roots, thicker root walls, and smaller apex diameters. In addition, we found that BBR promoted SCAPs osteogenesis in a time-dependent and concentration-dependent manner. BBR induced the expression of β-catenin and enhanced β-catenin entering into the nucleus, to up-regulate more runt-related nuclear factor 2 downstream. BBR enhanced root repair in immature teeth with apical periodontitis by activating the canonical Wnt/β-catenin pathway in SCAPs.
Animals ; Berberine ; pharmacology ; Cell Differentiation ; drug effects ; Dental Papilla ; Male ; Osteogenesis ; drug effects ; Periapical Periodontitis ; therapy ; Rats ; Stem Cells ; cytology ; drug effects ; metabolism ; Wnt Signaling Pathway ; drug effects ; Wnt3A Protein ; genetics ; metabolism ; X-Ray Microtomography

OBJECTIVE: To investigate the inhibitory effect of Zhenwu Decoction on ventricular hypertrophy in rats with uremic cardiomyopathy and explore the mechanism. METHODS: Cardiocytes isolated from suckling rats were divided into control group and indoxyl sulfate (IS) group, and the protein synthesis was assayed with [H]- leucine incorporation and cellular protein expressions were detected using Western blotting. Fifty SD rats were randomly divided into sham operation group, model group, and low- and high-dose Zhenwu Decoction treatment groups, and except for those in the sham operation group, all the rats underwent 5/6 nephrectomy. Four weeks after the operation, the rats in low- and high-dose treatment groups were given Zhenwu Decoction gavage at the dose of 4.5 g/kg and 13.5 g/kg, respectively; the rats in the sham-operated and model groups were given an equal volume of distilled water. After 4 weeks of treatment, serum levels of IS were determined, and cardiac and ventricular mass indexes were measured in the rats; cardiac ultrasound was performed and Western blotting was used to measure the expressions of BNP, p-ERK1/2, p-p38 and p-JNK in the myocardium. RESULTS: Rat cardiomyocytes treated with IS showed significantly enhanced protein synthesis and increased expression levels of BNP, p-erk1/2, and p-p38 as compared with the control cells ( < 0.01), but the expression of p-jnk was comparable between the two groups. In the animal experiment, the rats in the model group showed significantly increased serum creatinine (SCr) and urea nitrogen (BUN) levels, 24-h urine protein (24 hUpro), plasma IS level, left ventricular mass index (LVMI) and whole heart mass index (HMI) compared with those in the sham group ( < 0.01); Both LVESD and LVEDD were significantly reduced and LVAWS, LVAWD, LVPWS and LVPWD were significantly increased in the model rat, which also presented with obvious cardiomyocyte hypertrophy and increased myocardial expressions of BNP, p-ERK1/2, p-p38 and p-jnk ( < 0.01). Compared with the rats in the model group, the rats treated with low-dose and high-dose Zhenwu Decoction had significantly lowered levels of SCr, BUN, 24 hUpro and IS ( < 0.05) and decreased LVMI and HMI; LVESD, LVEDD, LVPWS, LVAWS, and LVAWD were improved more obviously in the high-dose group, and the myocardial expressions of BNP, p-ERK1/2, p-p38 and p-JNK was significantly downregulated after the treatment. CONCLUSIONS Zhenwu Decoctin can reduce plasma IS levels and inhibit ventricular hypertrophy to delay ventricular remodeling in rats with uremic cardiomyopathy.
Animals ; Blood Urea Nitrogen ; Cardiomegaly ; prevention & control ; Cardiomyopathies ; complications ; Creatinine ; blood ; Drugs, Chinese Herbal ; pharmacology ; Heart Ventricles ; Indican ; blood ; pharmacology ; Myocytes, Cardiac ; drug effects ; metabolism ; Nephrectomy ; Random Allocation ; Rats ; Rats, Sprague-Dawley