Hyaluronic acid (HA) possesses excellent biocompatibility, biodegradability, and non-immunogenicity, and exhibits active targeting capability to receptors such as cluster of differentiation 44 (CD44). Therefore, HA has become an important material for the design and preparation of drug delivery carriers in recent years. HA is rich in functional groups that can be chemically modified, but different modification methods and sites can affect its biological properties. This paper summarizes and discusses the effects of chemical modification on the biological properties of HA based on the formation mechanisms of such properties, as well as the derivatization and characterization methods of HA, so as to provide some reference for rational research on chemical modification of HA.

ObjectiveTo analyze the epidemiological characteristics of long COVID and to investigate its main influencing factors by examining individuals infected with SARS-CoV-2 between March and June 2022 in two communities in Shanghai, to lay the foundation for further research on the mechanism and clinical treatment of long COVID, and to provide the basis for the development of inexpensive, convenient, and feasible prevention and intervention strategies. MethodsA cross-sectional study was conducted, enrolling 6 410 individuals infected with SARS-CoV-2. Data were collected through a questionnaire survey. The incidence and common symptoms of long COVID were analyzed, along with their associations with demographic characteristics, medical history, and behavioral factors. A logistic regression model was used to identify the major factors associated with the development of long COVID symptoms. ResultsThe overall incidence rate of long COVID among the study population was 13.9%. The most commonly reported symptoms included fatigue (65.1%), attention disorders (23.1%), and cough (16.9%). The analysis showed that having underlying chronic diseases (OR=2.580, 95%CI: 2.165‒3.074), a history of allergies (OR=1.418, 95%CI: 1.003‒1.971), current smoking (OR=1.461, 95%CI: 1.013‒2.079), ever smoking (OR=2.462, 95%CI: 1.687‒3.551), a greater number of symptoms during the acute phase [1 symptom (OR=1.778, 95%CI: 1.459‒2.162), 2 symptoms (OR=2.749, 95%CI: 2.209‒3.409), ≥3 symptoms (OR=7.792, 95%CI: 6.333‒9.593)] and aggravated symptoms during the acute phase (OR=1.082, 95%CI: 1.070‒1.094) were factors associated with a higher risk of developing long COVID symptoms. Additionally, individuals who had consumed alcohol in the past year (OR=1.914, 95%CI: 1.344‒2.684) were more prone to objective long COVID symptoms. Among individuals under 50 years of age, females (OR=1.427, 95%CI: 1.052‒1.943) were more likely to develop objective long COVID symptoms. ConclusionThis study has identified the diversity of long COVID symptoms, which involve multiple organs and systems, including fatigue, attention disorders, cough, and joint pain. It has also revealed associations between long COVID and various demographic factors (e.g., age, gender), personal medical history (e.g., underlying chronic diseases, history of allergies), acute-phase characteristics (e.g., number and severity of symptoms), and behavioral factors (e.g., smoking, alcohol consumption). These findings highlight the need for further research and ongoing surveillance of long COVID and may inform the development of more targeted health management strategies for specific populations.

Colitis-associated cancer(CAC)is a specific type of colorectal cancer that develops from inflammatory bowel disease(IBD).Myeloid-derived suppressor cells(MDSCs)are a group of myeloid cells with immunosuppressive properties,and MDSCs in the tumor microenvironment proliferate and activate during the development of colitis-associated cancer,inhibiting T-cell production and impairing their function,which impedes the immunotherapeutic effect of colitis-associated cancer.In this paper,we review the immunosuppressive mechanisms of MDSCs in the development of inflammatory bowel disease to colitis-associated cancers and the current drugs targeting MDSCs for immunotherapy of inflammatory colorectal cancers,with a view to providing new strategies for the treatment of colitis-associated cancers.

Objective To investigate the effects of cinbufagin(CB)on the proliferation,migration and invasion ability as well as epithelial-mesenchymal transition(EMT)of human colon cells HCT116.Methods Logarithmically grown HCT116 cells were randomly divided into blank group and experimental-L,-M,-H groups;the blank group did not receive any treatment(0 nmol·L-1),and experimental-L,-M,-H groups were cultured in 1 640 medium containing 17.5,35 and 70 nmol·L-1 cinbufagin for 48 h.Cell counting kit-8(CCK-8)was used to detect the effect of cinbufagin on the survival rate of HCT116 cells;cloning assay was used to detect the effect of cinbufagin on the proliferation of HCT116 cells;cell scratch assay and Transwell assay were used to detect the effect of cinbufagin on the migration and invasive ability of HCT116 cells;Western blot was used to detect the expression levels of janus kinase 2(JAK2)/signal transducers and activators of transcription 3(STAT3)pathway and EMT-related proteins of HCT116 cells.Results The number of clone formation in blank group and experimental-L,-M,-H groups were 122.67±24.42,73.67±15.82,44.33±4.51 and 21.67±1.53;the rates of migration of scratches were(44.64±9.15)％,(26.91±2.94)％,(19.28±1.52)％and(6.33±2.30)％;the number of invaded cells were 120.33±1.15,58.33±9.07,33.33±1.53 and 18.33±3.21;the relative protein expression of phosphorylated JAK-2(p-JAK-2)/JAK-2 were 1.02±0.06,0.94±0.05,0.75±0.22 and 0.49±0.22;relative protein expression of phosphorylated STAT3(p-STAT3)/STAT3 were 0.89±0.10,0.72±0.04,0.65±0.06 and 0.52±0.18;relative protein expression of E-cadherin were 0.30±0.14,0.41±0.13,0.49±0.14 and 0.69±0.17;relative protein expression of N-cadherin were 0.96±0.11,0.78±0.04,0.69±0.12 and 0.40±0.15;Snail relative protein expression were 0.89±0.08,0.62±0.15,0.44±0.15 and 0.27±0.09;Vimentin relative protein expression were 0.92±0.09,0.76±0.13,0.63±0.01 and 0.43±0.09,respectively.The above indexes in experimental-H group showed statistically significant differences compared to blank group(all P＜0.05).Conclusion HCT116 can inhibit the invasion and metastasis of human colorectal cancer cells HCT116 by inhibiting epithelial-mesenchymal transition through JAK2/STAT3 pathway.

Objective To explore the mechanism of inhibition of colorectal cancer cells HT29 proliferation,migration and invasion by bufalin through Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)pathway.Methods Human colorectal cancer HT29 cells were randomly divided into control group and experimental-L,-M,-H groups.The cells in the control group were not treated,and the cells in the experimental-L,-M,-H groups were treated with 2.5,5.0 and 10.0 μmol·L-1 bufalin for 48 h.After HT29 cells were infected with FLAG STAT3 lentivirus,the cells were divided into lentivirus infection group and experiment-H(10.0 pmol·L-1 bufalin)+lentivirus infection group.Cell viability was detected by cell counting kit 8(CCK-8).Cloning experiment to verify cell proliferation rate;Transwell experiment verified the migration ability of cells after bufalin treatment;the transfection efficiency of lentivirus and the expression of cell-related proteins were detected by Western blot.Results After 48 h of drug action,the number of cells in the control group,experimental-L,-M,-H groups were 1 003.25±255.53,698.00±152.25,562.13±31.56 and 449.50±82.40,respectively;the number of invasive cells were 932.00±188.84,742.22±108.64,514.67±124.82 and 343.56±86.42,respectively;the protein expression level of p-JAK2 were 1.37±0.27,0.97±0.06,0.74±0.06 and 0.39±0.12,respectively.The number of cells in the control group,experimental-H group,lentivirus infection group,and experimental-H+lentivirus infection group were 906.88±211.71,389.00±143.08,1 279.38±210.34 and 604.75±12.52,respectively;the number of invasive cells were 671.22±44.74,246.11±28.16,1 080.78±119.13 and 574.78±16.23,respectively.Compared with the control group,there were statistically significant differences in the number of cell proliferation,the number of cell invasion and the relative levels of p-JAK2 in the experimental-M and-H groups(all P＜0.05).Compared with the control group,the number of cell proliferation and the number of cell invasion in the experimental-H group,the lentivirus infection group,and the high-dose experimental+lentivirus infection group were statistically significant(all P＜0.05).Conclusion Bufalin can inhibit the proliferation,migration and invasion of colorectal cancer by activating the JAK2/STAT3 signalling pathway.

Objective:To explore the effect and safety of mesenchymal stem cell exosome microneedle introduction in the treatment of melasma.Methods:Thirty cases of female patients with stable melasma in the Department of Dermatology, Changsha Meilai Medical Beauty Hospital, aged (36±5) years and with a disease duration of (42.4±20.7) months, from July 2021 to July 2022, were retrospectively included. According to Fitzpatrick skin typing, 23 cases of type Ⅲ and 7 cases of type Ⅳ were included. All patients were locally anesthetized with lidocaine cream for 30 min, and rolled with a 0.5 mm needle in a zigzag pattern with even force, in the order of the right cheek, the left cheek, the forehead, the nose, the mandible, and the upper lip. During the rolling process, 3 ml of MSC exosome medical liquid wound dressing was applied to the facial skin, and after it was fully absorbed, exosome was locally readministered in the area of melasma. Treatment ended with a slight redness at the site of application. 1 MSC exosome wound dressing was appllied as a cold compress for 15 min after treatment. Treatment was given once every 2 weeks for 6 consecutive sessions. All the patients were followed up at 4 and 12 weeks after the last session, and the area and severity index of melasma (MASI) were scored before and after the treatment, the clinical efficiency and patient satisfaction rate and the incidence of adverse reactions were also counted.Results:At 4 and 12 weeks after the end of treatment, the skin color of all 30 patients was brighter than that before treatment, and no recurrence of melasma symptoms seen. At 12 weeks after the end of treatment, the decrease rate of MASI score was 66.1%, among which the decrease rate of MASI score in patients with type Ⅲ melasma was 63.9%, and the decrease rate of MASI score in patients with type Ⅳ melasma was 63.9%. Among the 30 patients, 1 case was cured, 25 cases showed obvious improved, 4 cases were improved, and no cases were ineffective, with an effective rate of 86.7% (26/30). Five patients were very satisfied, 18 patients were satisfied, 6 patients were generally satisfied, and 1 patient was dissatisfied; the patient satisfaction rate was 76.7% (23/30). No serious adverse reactions occurred in all patients.Conclusions:MSC exosome microneedle introduction is safe and effective in the treatment of melasma without serious adverse reactions.

The Dionex CaboPac^TM PA10 BioLC^TM Analyical 2 mm × 250 mm column was used with a protective column (Dionex CaboPac^TM PA10 BioLC^TM Guard 2 mm × 50 mm). 100 mmol·L^-1 sodium hydroxide solution was used as eluent; the flow rate was 0.25 mL·min^-1. Sample tray temperature: 35 ℃. The pulse amperometric detector was adopted, and the waveform was Gold CWE, Ag-AgCl RE, Carbo, Quad. The samples were cultured with 8 concentrations of glycogen substrates (0.31, 1.25, 2.5, 5, 10, 20, 30, and 40 mg·mL^-1). D-Glucose concentrations were measured at 5 different time points (T0, T1, T2, T3 and T4). The glucose concentration from T1 to T4 minus the glucose concentration at T0. The reaction rate was calculated at different glycogen substrate concentrations. These reaction rates are plotted against substrate concentrations using Michaelis-Menten equation. The kinetic parameters were expressed as V_max (nmol·mg^-1·min^-1) and K_m (mg·mL^-1). The RSD of glucose standard curve R² (n = 6, linear range: 1.25-500 μmol·L^-1) was 0.1% and the RSD (n = 6) of the slope of the standard curve was 2.2%. The mean limit of quantitation was 0.14 μmol·L^-1, and the mean limit of detection was 0.05 μmol·L^-1. The RSD of K_m and V_max were 4.4% and 4.6% respectively in three separate experiments. The durability of the method was good. The method was developed for the on-line automatic determination of the hydrolysis kinetics of acid α-glucosidase (GAA) for injection by ion chromatography. The method has good precision, repeatability and durability, and can be used for the determination of glycogen hydrolysis kinetics of GAA for injection, and could reference value for the enzyme kinetics evaluation of recombinant enzyme replacement therapy.

OBJECTIVE: To establish an intestinal organoid model that mimic acute graft versus host disease (aGVHD) caused intestinal injuries by using aGVHD murine model serum and organoid culture system, and explore the changes of aGVHD intestine in vitro by advantage of organoid technology. METHODS: 20-22 g female C57BL/6 mice and 20-22 g female BALB/c mice were used as donors and recipients for bone marrow transplantation, respectively. Within 4-6 h after receiving a lethal dose (8.0 Gy) of γ ray total body irradiation, a total of 0.25 ml of murine derived bone marrow cells (1×10⁷/mice, n=20) and spleen nucleated cells (5×10⁶/mice, n=20) was infused to establish a mouse model of aGVHD (n=20). The aGVHD mice were anesthetized at the 7th day after transplantation, and the veinal blood was harvested by removing the eyeballs, and the serum was collected by centrifugation. The small intestinal crypts of healthy C57BL/6 mice were harvested and cultivated in 3D culture system that maintaining the growth and proliferation of intestinal stem cells in vitro. In our experiment, 5%, 10%, 20% proportions of aGVHD serum were respectively added into the organoid culture system for 3 days. The formation of small intestinal organoids were observed under an inverted microscope and the morphological characteristics of intestinal organoids in each groups were analyzed. For further evaluation, the aGVHD intestinal organoids were harvested and their pathological changes were observed. Combined with HE staining, intestinal organ morphology evaluation was performed. Combined with Alcian Blue staining, the secretion function of aGVHD intestinal organoids was observed. The distribution and changes of Lgr5⁺ and Clu⁺ intestinal stem cells in intestinal organoids were analyzed under the conditions of 5%, 10% and 20% serum concentrations by immunohistochemical stainings. RESULTS: The results of HE staining showed that the integrity of intestinal organoids in the 5% concentration serum group was better than that in the 10% and 20% groups. The 5% concentration serum group showed the highest number of organoids, the highest germination rate and the lowest pathological score among experimental groups, while the 20% group exhibited severe morphological destruction and almost no germination was observed, and the pathological score was the highest among all groups(t=3.668, 4.334,5.309,P<0.05). The results of Alican blue staining showed that the secretion function of intestinal organoids in serum culture of aGVHD in the 20% group was weaker than that of the 5% group and 10% of the organoids, and there was almost no goblet cells, and mucus was stainned in the 20% aGVHD serum group. The immunohistochemical results showed that the number of Lgr5⁺ cells of intestinal organoids in the 5% group was more than that of the intestinal organoids in the 10% aGVHD serum group and 20% aGVHD serum group. Almost no Clu⁺ cells were observed in the 5% group. The Lgr5⁺ cells in the 20% group were seriously injuried and can not be observed. The proportion of Clu⁺ cells in the 20% group significantly increased. CONCLUSION The concentration of aGVHD serum in the culture system can affect the number and secretion function of intestinal organoids as well as the number of intestinal stem cells in organoids. The higher the serum concentration, the greater the risk of organoid injury, which reveal the characteristics of the formation and functional change of aGVHD intestinal organoids, and provide a novel tool for the study of intestinal injury in aGVHD.
Mice ; Female ; Animals ; Mice, Inbred C57BL ; Bone Marrow Transplantation ; Graft vs Host Disease ; Stem Cells ; Organoids

Humans ; Adult ; Lymphoma, Mantle-Cell/drug therapy* ; Rituximab/therapeutic use* ; Bendamustine Hydrochloride/therapeutic use* ; Lymphoma, B-Cell/pathology* ; Lymphoma, Non-Hodgkin/drug therapy* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use*

The twenty-first century has already recorded more than ten major epidemics or pandemics of viral disease, including the devastating COVID-19. Novel effective antivirals with broad-spectrum coverage are urgently needed. Herein, we reported a novel broad-spectrum antiviral compound PAC5. Oral administration of PAC5 eliminated HBV cccDNA and reduced the large antigen load in distinct mouse models of HBV infection. Strikingly, oral administration of PAC5 in a hamster model of SARS-CoV-2 omicron (BA.1) infection significantly decreases viral loads and attenuates lung inflammation. Mechanistically, PAC5 binds to a pocket near Asp49 in the RNA recognition motif of hnRNPA2B1. PAC5-bound hnRNPA2B1 is extensively activated and translocated to the cytoplasm where it initiates the TBK1-IRF3 pathway, leading to the production of type I IFNs with antiviral activity. Our results indicate that PAC5 is a novel small-molecule agonist of hnRNPA2B1, which may have a role in dealing with emerging infectious diseases now and in the future.
Animals ; Mice ; Antiviral Agents/pharmacology* ; COVID-19 ; Hepatitis B virus ; Interferon Type I/metabolism* ; SARS-CoV-2/drug effects* ; Heterogeneous-Nuclear Ribonucleoprotein Group A-B/antagonists & inhibitors*