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Objective:To investigate the antibacterial and osteogenic properties of biomimetic mineralized iodine-loaded coating with micro-nano topography on the surface of bone implants.Methods:After the fiber network structure of sodium hydrogen titanate was constructed by alkali thermal reaction on the surface of Ti6Al4V (noted as AT), it was biomimetically mineralized in the modified simulated body fluid to form a micro-nano topology with high specific surface area (noted as AT-CaP), and finally loaded with PVPI to construct a novel antibacterial osseointegration coating (noted as AT-CaP-PVPI). The study was conducted in AT, AT-CaP, and AT-CaP-PVPI groups, in each of which 3 parallel experiments were performed. The morphology and colony counting of Staphylococcus aureus on the coating surface were observed to detect the in vitro antibacterial performance of the coating. Fifteen male SD rats were randomly divided into 3 groups ( n=5): AT, AT-CaP, and AT-CaP-PVPI. After intramedullary injection of Staphylococcus aureus into the lower end of the femur in the SD rats, titanium rods coated with AT, AT-CaP, and AT-CaP-PVPI were inserted into the marrow cavity. The osteogenesis, volume ratio of new bone mass and number of trabeculae on the surface of the femoral implants were compared between the 3 groups 4 weeks after operation. Results:In AT and AT-CaP groups, a large number of bacteria grew in their inherent elliptical or spherical shape on the implant surface and a large number of colonies were seen on the plate; in AT-CaP-PVPI group, the bacteria on the coating surface exhibited membrane deformation and depression, some of them were completely broken and dissolved, and a large number died. There was almost no new bone formation around the implants in AT group; new bone scattered around the implants with discontinuous distribution in AT-CaP group; a great amount of new bone was seen around the implants with even distribution but no signs of infection in AT-CaP-PVPI group. The volume ratio of new bone mass and the number of trabeculae on the implant surface in AT-CaP-PVPI group were 0.453±0.206 and 6.055±0.536, respectively, significantly higher than those in AT group (0.046±0.028 and 1.667±1.249) and AT-CaP group (0.188±0.052 and 3.804±0.889) ( P<0.05). Conclusion:Biomimetic mineralized iodine-loaded coating with micro-nano topography on the surface of bone implants shows good antibacterial and osteogenic properties.
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Objective:To establish the hepatic organoid of hepatitis B virus (HBV) infection on the basis of induced pluripotent stem cells (iPSC) and an inverted colloidal crystal polyethylene glycol scaffold (ICC), and to evaluate the antiviral effect of nucleoside drugs.Methods:iPSC was differentiated into hepatocyte-like cells (HLC), and inoculated into ICC to construct a hepatic organoid. The relative mRNA expressions of Nanog homeobox (NANOG), sex determining region Y-box (SOX) 2, SOX17, forkhead box protein A2 (FOXA2), alpha fetoprotein (AFP) and albumin (ALB) were detected by real time quantitative polymerase chain reaction (RT-qPCR). Confocal laser microscopy was used to photograph the three-dimension (3D) structure of organs. The expression of sodium taurocholate cotransporting polypeptide (NTCP) in HLC was analyzed by Western blot and immunofluorescence. HepG2.2.15 cells were used to extract HBV virus particles to infect hepatic organoid. The relative expression of HBV pregenome RNA (pgRNA) in cells was detected by RT-qPCR. The expressions of hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg) in cytoplasm were observed under confocal laser microscopy. A total of 0.5 μmol/L entecavir and 0.5 μmol/L lamivudine were used to treat the infected cells respectively. The relative expression of HBV pgRNA in infected and uninfected cells was detected by RT-qPCR. Independent sample t test and one-way analysis of variance were used for statistical analysis. Results:Within 21 days of iPSC differentiation, the mRNA expressions of NANOG and SOX2 in stem cells markers decreased ( F=158.90 and 8.31, respectivley; P<0.001 and P=0.002, respectively), while the mRNA expressions of SOX17 and FOXA2 in the endoderm increased first and then decreased ( F=37.23 and 82.57, respectively, both P<0.001). In the later stage of differentiation, the mRNA expressions of AFP and ALB in liver cells increased ( F=4.65 and 34.64, respectively, P=0.012 and P<0.001, respectively), and all differences were statistically significant. NTCP was highly expressed in differentiated cells detected by Western blot and fluorescence microscopy, the protein expression level was 0.803±0.099. Confocal laser microscopy confirmed that the differentiated cells expressed ALB and presented spherical structure in ICC. The expression of HBV pgRNA and the immunostaining of HBsAg and HBcAg confirmed that HBV successfully infected hepatic organoid. Three days after the application of entecavir and lamivudine, the HBV pgRNA level decreased significantly both in entecavir group (0.665±0.220) and lamivudine group (0.503±0.117) compared to the uninfected cells (3.347±0.454), and the differences were both statistically significant ( t=10.53 and 12.72, respectively, both P<0.001). Conclusions:HLC display hepatic specific genes ALB and NTCP. Hepatic organoids constructed with iPSC and ICC have human liver function and can be infected by HBV. Entecavir and lamivudine could effectively inhibit the replication of HBV in hepatic organoids.
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Objective:To explore the effect and mechanism of dendritic cell derived exosomes (Dexs) loading ubiquitinated (Ub) hepatitis D antigen (HDAg) on activating specific cytotoxic T lymphocytes (CTL).Methods:Ub-S-HDAg-Dexs were co-cultured with dendritic cells (DC) which were from the femora of C57BL/6 mice for 48 h, then flow cytometry was used to detect the maturity of DC (CD86, CD80 and major histocompatibility complex (MHC) Ⅱ). The spleen-derived T lymphocytes from C57BL/6 mice were added in vitro to activate DC and co-cultivated for 72 h. The T cells were divided into Ub-S-HDAg-Dexs group (add 50 μg/mL Ub-S-HDAg-Dexs), Blank-Dexs group (add 50 μg/mL DC derived exosomes without plasmid transfection), Con-Dexs group (add 50 μg/mL DC derived exosomes transfected by cantrol plasmid), PBS group (add 50 μL/mL phosphate buffered saline), and Ub-S-HDAg-Dexs+ AG490 group (add 50 μg/mL Ub-S-HDAg-Dexs, DC and T lymphocytes stimulated by exosomes, and 50 μmol/L AG490 was also added to the cell mix). Flow cytometry was used to detect CD8 + T cells secreting interferon-gamma, non-radioactive lactate dehydrogenase release test to detect the killing activity of specific CTL. Real-time quantitative polymerase chain reaction (PCR) and Western blotting were used to detect the mRNA and protein expressions of JAK kinase (JAK) 2, GATA-binding protein 3 (GATA3), T-bet, signal transduction and activator of transcription (STAT) 1 and STAT4. Independent sample t test were used for statistical analysis. Results:The positive rates of the surface molecules CD80, CD86, MHCⅡof DC stimulated by Ub-S-HDAg-Dexs were 83.850%±0.219%、68.910%±0.134%、84.320%±0.445%, respectively.In the Ub-S-HDAg-Dexs group, the rate of CD8 + T cells secreting interferon-gamma was 6.420%±0.028%, which was higher than those of other groups, including PBS group, Blank-Dexs group, Con-Dexs group and Ub-S-HDAg-Dexs+ AG490 group ( t=90.78, 30.32, 63.06 and 85.42, respectively, all P<0.001). The cytotoxicity of T cells in the Ub-S-HDAg-Dexs group was 82.4%±3.9%, which was higher than those of other groups ( t=17.28, 9.74, 3.95 and 15.89, respectively, all P<0.050). The relative mRNA expressions of JAK2, T-bet, STAT1, STAT4 in Ub-S-HDAg-Dexs group were higher than those in other groups, including Con-Dexs group ( t=10.74, 32.34, 13.00 and 16.28, respectively, all P<0.001), Blank-Dexs group ( t=15.05, 21.51, 6.46 and 13.12, respectively, all P<0.050), PBS group ( t=21.83, 41.42, 7.30 and 17.50, respectively, all P<0.050), Ub-S-HDAg-Dexs+ AG490 group ( t=35.75, 20.69, 17.02 and 17.07, respectively, all P<0.001), and the differences were all statistically significant. The protein expressions of T-bet, STAT1, STAT4 in Ub-S-HDAg-Dexs group increased compared with those in PBS group ( t=346.70, 57.54 and 55.81, respectively, all P<0.001), with statistical significance. In the presence of AG490, the protein expressions of T-bet, STAT1 and STAT4 decreased compared with those in Ub-S-HDAg-Dexs group, and the differences were statistically significant ( t=355.40, 52.79 and 126.10, respectively, all P<0.001). Conclusions:Ubiquitinated HDAg transported by exosomes could effectively promote DC maturation, induce T lymphocyte differentiation, and generate specific CTL responses, which provides a new idea for the treatment of hepatitis D.
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Objective:To clarify the effect of ubiquitination hepatitis B virus core antigen (Ub-HBcAg) on dendritic cells (DC) autophagy, and to explore the mechanism of autophagy in enhancing DC antigen presentation and inducing hepatitis B virus-specific cytotoxic T lymphocyte (CTL) responses.Methods:Ub-HBcAg lentiviral vector (LV-Ub-HBcAg), lentiviral vector-hepatitis B virus core antigen (LV-HBcAg) and no-load plasmid LV (LV) were constructed and packaged. DC2.4 cells were divided into LV-Ub-HBcAg group, LV-HBcAg group and LV group. The blank control group (NC group) was also set. The protein expression of autophagy-related protein P62, microtubule associated protein 1 light chain 3 beta (LC3B), autophagy related 5(ATG5) and Beclin-1 were detected by Western blotting. The expressions of co-stimulatory molecules such as CD86, CD80 and major histocompatibility complex (MHC)-Ⅱ were detected by flow cytometry. Cell counting kit-8 (CCK-8) method was used to detect T lymphocytes proliferation. The non-radioactive lactic acid dehydrogenase (LDH) release method was applied to detect the killing ability of CTL. Statistical analysis was conducted by independent sample t test. Results:The relative protein expressions of LC3B-Ⅱ/LC3B-Ⅰ, Beclin-1 and ATG5 in NC group were 0.445±0.076, 0.522±0.026 and 0.761±0.038, respectively, which were all lower than those in LV-Ub-HBcAg group (0.926±0.021, 0.919±0.016 and 1.451±0.028, respectively). The relative protein expression of P62 in the NC group was higher than that in LV-Ub-HBcAg group ((1.875±0.016) vs (0.647±0.121)). The differences were all statistically significant ( t=6.102, 9.842, 17.490 and 10.590, respectively, all P<0.01). The expressions of CD86 (75.51%), CD80 (83.35%), MHC-Ⅱ (66.66%) in the LV-Ub-HBcAg group were high, and those in the NC group were 8.03%, 7.49%, 0.04%, respectively. The specific CTL killing rate ((65.310±2.091)%) of the LV-Ub-HBcAg group was significantly higher than both NC group ((14.400±0.497)%) and LV-HBcAg group ((54.870±1.443)%), and the differences were both statistically significant ( t=23.690 and 4.111, respectively, both P<0.05). Conclusion:Ub-HBcAg promotes the DC autophagy, up-regulates the expressions of costimulatory molecules on cell surface of DC to induce the maturation and activation, and then stimulates T lymphocyte to induce a stronger specific CTL response under the effort of ubiquitination.
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PURPOSE: The effect of air pollution-related particulate matter (PM) on epithelial barrier function and tight junction (TJ) expression in human nasal mucosa has not been studied to date. This study therefore aimed to assess the direct impact of PM with an aerodynamic diameter less than 2.5 μm (PM2.5) on the barrier function and TJ molecular expression of human nasal epithelial cells. METHODS: Air-liquid interface cultures were established with epithelial cells derived from noninflammatory nasal mucosal tissue collected from patients undergoing paranasal sinus surgery. Confluent cultures were exposed to 50 or 100 µg/mL PM2.5 for up to 72 hours, and assessed for 1) epithelial barrier integrity as measured by transepithelial resistance (TER) and permeability of fluorescein isothiocyanate (FITC) 4 kDa; 2) expression of TJs using real-time quantitative polymerase chain reaction and immunofluorescence staining, and 3) proinflammatory cytokines by luminometric bead array or enzyme-linked immunosorbent assay. RESULTS: Compared to control medium, 50 and/or 100 µg/mL PM2.5-treatment 1) significantly decreased TER and increased FITC permeability, which could not be restored by budesonide pretreatment; 2) significantly decreased the expression of claudin-1 messenger RNA, claudin-1, occludin and ZO-1 protein; and 3) significantly increased production of the cytokines interleukin-8, TIMP metallopeptidase inhibitor 1 and thymic stromal lymphopoietin. CONCLUSIONS: Exposure to PM2.5 may lead to loss of barrier function in human nasal epithelium through decreased expression of TJ proteins and increased release of proinflammatory cytokines. These results suggest an important mechanism of susceptibility to rhinitis and rhinosinusitis in highly PM2.5-polluted areas.
Assuntos
Humanos , Asma , Budesonida , Claudina-1 , Citocinas , Ensaio de Imunoadsorção Enzimática , Células Epiteliais , Fluoresceína , Fluoresceína-5-Isotiocianato , Imunofluorescência , Interleucina-8 , Mucosa , Mucosa Nasal , Ocludina , Material Particulado , Permeabilidade , Reação em Cadeia da Polimerase , Rinite , RNA Mensageiro , Junções ÍntimasRESUMO
2019 novel coronavirus (2019-nCoV) is one of the beta coronaviruses and was identified as the pathogen of the severe "coronavirus disease 2019 (COVID-19)" in 2019. China has formally included the 2019-nCoV in the statutory notification and control system for infectious diseases according to the Law of the People's Republic of China on the Prevention and Treatment of Infectious Diseases. Currently, the national defending actions on the 2019-nCoV in China is in a critical period. Burn Department is also confronted with risk of infection by the 2019-nCoV. According to the guidelines on the diagnosis and treatment of COVID-19 (6th trial edition), the latest relative literature at home and abroad, the features of the COVID-19, recommendations for the COVID-19 prevention and control issued by the National Health Commission of China, and management experience of diagnosis and treatment in the related disciplines, we put forward recommendations for the medical practices of burn treatment during the outbreak of the COVID-19 in outpatient and emergency treatment, inpatient treatment, operation and ward management, etc. We hope these recommendations could benefit the professionals of the same occupation as us and related hospital managers, improve the treatment of burn during the outbreak of the COVID-19, and avoid or reduce the risk of infection of medical staff .
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In order to improve the quality of the clinical teaching of postgraduates in burn surgery and cultivate high-quality interdisciplinary talents , this study explores the significance and role of the concept of holistic integrative medicine in the clinical teaching of postgraduates in burn surgery. By cultivating the thinking of holistic integrative medicine among teachers and students, a variety of teaching methods are used to integrate burn surgery with multiple disciplines such as rehabilitation medicine, plastic surgery, psychology , and pathophysiology in the clinical teaching of postgraduates . The results show that the introduction of the concept of holistic integrative medicine in the clinical teaching of postgraduates can enhance their enthusiasm for learning, improve the quality of teaching, and provide a reference for exploring the training model for high-quality talents in burn surgery.