Objective:To construct a calcium alginate (ALG-Ca 2+) composite hydrogel loaded with chlorella protein (Cp) (ALG-Ca 2+@Cp) and investigate its combined effect with microwave hyperthermia on the proliferation, apoptosis, and immune activation of mouse pancreatic cancer cells. Methods:ALG-Ca 2+@Cp was prepared using a physical cross-linking method and its physiochemical properties was characterized via scanning electron microscopy, rheological analysis, Ca 2+ release experiments, and microwave thermal conversion tests. The BCA protein quantification assay was used to evaluate the adsorption capacity of ALG-Ca 2+@Cp for pancreatic cancer cell antigens. The effects of ALG-Ca 2+@Cp extract combined with microwave intervention on pancreatic cancer cell proliferation, apoptosis protein expression, and cell viability were assessed using CCK-8 assays, ELISA, and Calcein-AM/PI double fluorescence staining. Flow cytometry was performed to determine the maturation-promoting ability of ALG-Ca 2+@Cp on immature mouse bone marrow-derived dendritic cells (BMDCs). Results:ALG-Ca 2+@Cp exhibited a three-dimensional network structure with a storage modulus (G') greater than the loss modulus (G''), demonstrating typical hydrogel properties. The hydrogel loaded with 0.5 mol/ml Ca 2+ reached 48°C after 5 minutes of microwave irradiation at 5.0 W/cm 2, and Ca 2+ release plateaued within 5 minutes. ALG-Ca 2+@Cp effectively adsorbed pancreatic cancer cell antigens. Combined with microwave treatment, it significantly reduced pancreatic cancer cell proliferation ( A450 value 0.39±0.07 vs 2.78±0.15) and increased apoptosis markers calreticulin (CRT) and high mobility group box-1 protein (HMGB1) [(557.09±37.84) pg/ml vs (135.14±11.84) pg/ml, (4.77±0.18) ng/ml vs (1.6±0.16) ng/ml], leading to decreased cell viability; and all the differences were statistically significant (all P value <0.05). ALG-Ca 2+@Cp synergistically promoted the maturation of immature BMDCs in the presence of pancreatic cancer antigens, with a CD 80+ positivity rate of (75.67±6.53)%. Conclusions:ALG-Ca 2+@Cp is successfully constructed. Its combination with microwave hyperthermia can significantly enhance the cytotoxicity and immune activation against mouse pancreatic cancer cells by targeting intracellular antigens and inducing immunogenic cell death.

BACKGROUND:It has been proved that induced pluripotent stem cells can differentiate into cardiomyocytes,but there are few reports on the maturity of differentiated cardiomyocytes.OBJECTIVE:To explore the effect of prolonging the induced differentiation time on the morphology,sarcomere length,binuclear cell content,cardiac gene expression,cardiac protein expression,and mitochondrial function of cardiomyocytes derived from induced pluripotent stem cells.METHODS:Bone morphogenetic protein 4,CH IR 99021,and IWR1 were used to induce pluripotent stem cells to differentiate into cardiomyocytes,and differentiated cardiomyocytes were collected on days 20 and 40 respectively.The expression levels of cardiac genes and proteins in differentiated cardiomyocytes were detected by RT-PCR and immunofluorescence,respectively.LAS X image analysis software was used to analyze the morphology and sarcomere length of differentiated cardiomyocytes.MitoTracker Green FM mitochondrial staining was used to detect total mitochondria.JC-1 mitochondrial staining was used to detect mitochondrial membrane potential.RESULTS AND CONCLUSION:Differentiated card io myocytes on day 40 had longer cell circumference and sarcomere length,and larger cell area than those on day 20(P＜0.05).The proportion of multinucleated cells rose sharply from about 16％on day 20 to about 29％on day 40(P＜0.05).Differentiated cardiomyocytes on day 40 had gene expression levels that were more similar to those of the primary cardiomyocytes,and the expression levels of SERCA2A,Cx-43,and α-MHC genes were significantly higher than on day 20(P＜0.05).Compared with the differentiated cardiomyocytes on day 20,the expression density of TNNT2 and α-MHC protein was relatively higher,the distribution density of mitochondria was larger,and the number of functional mitochondria was greater on day 40(P＜0.05).The results show that prolonging the induced differentiation time can increase the maturity of differentiated cardiomyocytes by increasing the length of sarcomere and the number of functional mitochondria,as well as improving the expression levels of cardiac genes and proteins.

BACKGROUND:It has been proved that induced pluripotent stem cells can differentiate into cardiomyocytes,but there are few reports on the maturity of differentiated cardiomyocytes.OBJECTIVE:To explore the effect of prolonging the induced differentiation time on the morphology,sarcomere length,binuclear cell content,cardiac gene expression,cardiac protein expression,and mitochondrial function of cardiomyocytes derived from induced pluripotent stem cells.METHODS:Bone morphogenetic protein 4,CH IR 99021,and IWR1 were used to induce pluripotent stem cells to differentiate into cardiomyocytes,and differentiated cardiomyocytes were collected on days 20 and 40 respectively.The expression levels of cardiac genes and proteins in differentiated cardiomyocytes were detected by RT-PCR and immunofluorescence,respectively.LAS X image analysis software was used to analyze the morphology and sarcomere length of differentiated cardiomyocytes.MitoTracker Green FM mitochondrial staining was used to detect total mitochondria.JC-1 mitochondrial staining was used to detect mitochondrial membrane potential.RESULTS AND CONCLUSION:Differentiated card io myocytes on day 40 had longer cell circumference and sarcomere length,and larger cell area than those on day 20(P＜0.05).The proportion of multinucleated cells rose sharply from about 16％on day 20 to about 29％on day 40(P＜0.05).Differentiated cardiomyocytes on day 40 had gene expression levels that were more similar to those of the primary cardiomyocytes,and the expression levels of SERCA2A,Cx-43,and α-MHC genes were significantly higher than on day 20(P＜0.05).Compared with the differentiated cardiomyocytes on day 20,the expression density of TNNT2 and α-MHC protein was relatively higher,the distribution density of mitochondria was larger,and the number of functional mitochondria was greater on day 40(P＜0.05).The results show that prolonging the induced differentiation time can increase the maturity of differentiated cardiomyocytes by increasing the length of sarcomere and the number of functional mitochondria,as well as improving the expression levels of cardiac genes and proteins.

Objective:To construct a calcium alginate (ALG-Ca 2+) composite hydrogel loaded with chlorella protein (Cp) (ALG-Ca 2+@Cp) and investigate its combined effect with microwave hyperthermia on the proliferation, apoptosis, and immune activation of mouse pancreatic cancer cells. Methods:ALG-Ca 2+@Cp was prepared using a physical cross-linking method and its physiochemical properties was characterized via scanning electron microscopy, rheological analysis, Ca 2+ release experiments, and microwave thermal conversion tests. The BCA protein quantification assay was used to evaluate the adsorption capacity of ALG-Ca 2+@Cp for pancreatic cancer cell antigens. The effects of ALG-Ca 2+@Cp extract combined with microwave intervention on pancreatic cancer cell proliferation, apoptosis protein expression, and cell viability were assessed using CCK-8 assays, ELISA, and Calcein-AM/PI double fluorescence staining. Flow cytometry was performed to determine the maturation-promoting ability of ALG-Ca 2+@Cp on immature mouse bone marrow-derived dendritic cells (BMDCs). Results:ALG-Ca 2+@Cp exhibited a three-dimensional network structure with a storage modulus (G') greater than the loss modulus (G''), demonstrating typical hydrogel properties. The hydrogel loaded with 0.5 mol/ml Ca 2+ reached 48°C after 5 minutes of microwave irradiation at 5.0 W/cm 2, and Ca 2+ release plateaued within 5 minutes. ALG-Ca 2+@Cp effectively adsorbed pancreatic cancer cell antigens. Combined with microwave treatment, it significantly reduced pancreatic cancer cell proliferation ( A450 value 0.39±0.07 vs 2.78±0.15) and increased apoptosis markers calreticulin (CRT) and high mobility group box-1 protein (HMGB1) [(557.09±37.84) pg/ml vs (135.14±11.84) pg/ml, (4.77±0.18) ng/ml vs (1.6±0.16) ng/ml], leading to decreased cell viability; and all the differences were statistically significant (all P value <0.05). ALG-Ca 2+@Cp synergistically promoted the maturation of immature BMDCs in the presence of pancreatic cancer antigens, with a CD 80+ positivity rate of (75.67±6.53)%. Conclusions:ALG-Ca 2+@Cp is successfully constructed. Its combination with microwave hyperthermia can significantly enhance the cytotoxicity and immune activation against mouse pancreatic cancer cells by targeting intracellular antigens and inducing immunogenic cell death.

Objective:To explore the properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle (AgNP) Chlorella (hereinafter referred to as the composite hydrogel) and its effects on healing of infected full-thickness skin defect wounds in mice. Methods:The research was an experimental research. The simple gelatin-polyethylene glycol hydrogel (hereinafter referred to as the simple hydrogel) and the composite hydrogel were prepared, and the appearance and injectability of the two hydrogels were observed at 55 and 37 ℃, and under the irradiation of 808 nm near-infrared light, respectively. An electronic universal testing machine was employed to assess the tensile and compressive stress-strain properties of both types of hydrogels at room temperature. Additionally, the cyclic compressive stress-strain properties of the composite hydrogel were examined at 80% of the maximum compressive stress. Staphylococcus aureus or Escherichia coli solution was added to phosphate buffer solution (PBS), simple hydrogel, and composite hydrogel, respectively. The part of composite hydrogel containing Staphylococcus aureus or Escherichia coli solution was irradiated with near-infrared light for 5 minutes. After each sample was incubated for 6 h, the dilution plating method was used to detect and calculate the mortality rates of the two bacteria at 24 h of culture ( n=5). The discarded foreskin tissue was taken from a 6-year-old healthy boy admitted to the Department of Urology of the First Affiliated Hospital of Naval Medical University for circumcision. Primary human fibroblasts (HFbs) were isolated using the enzyme extraction method, routinely cultured to the 3 rd to 6 th passages for subsequent cellular experiments. Composite hydrogel extracts with final mass concentrations of 100.0, 50.0, 25.0, 12.5, and 0 mg/mL were respectively prepared and used to culture HFbs, and the cell proliferation after 24 h of culture was detected using a cell counting kit 8 ( n=3). A total of twenty 6-8 weeks old C57BL/6J female mice were utilized, and a full-thickness skin defect was surgically created on the back of each mouse. The wounds were infected with Staphylococcus aureus solution. The infected mice were divided into blank control group, simple hydrogel group, composite hydrogel group, and combined treatment group according to the random number table, and the wounds were treated with PBS, simple hydrogel, composite hydrogel, and composite hydrogel+light irradiation (under the irradiation of 808 nm near-infrared light for 5 min), respectively, with 5 mice in each group. On post injury day (PID) 0 (immediately after the first wound treatment), 3, 7, and 14, an overall assessment of wound exudation and healing were conducted, and the wound healing rates on PID 7 and 14 were calculated ( n=5). On PID 14, hematoxylin-eosin staining was performed to observe histopathological changes in the mouse wound. Results:Both simple hydrogel and composite hydrogel were in a solution state at 55 ℃ and transition to a gel state when cooling to 37 ℃. After the two hydrogels were irradiated by near-infrared light, only the composite hydrogel reheated up and returned to the solution state again with injectability. The maximum tensile stress of the composite hydrogel was up to 301.42 kPa, with a corresponding strain of 87.19%; the maximum compressive stress was up to 413.79 kPa, with a corresponding strain of 91.67%, which was similar to the tensile and compressive properties of the simple hydrogel. After 10 compression cycles, the maximum compressive stress of the composite hydrogel still reached 84.1% of the first compressive stress. After 24 h of culture, the mortality rate of Staphylococcus aureus treated with simple hydrogel was significantly higher than that treated with PBS ( P<0.05); the mortality rates of Escherichia coli and Staphylococcus aureus treated with composite hydrogel alone were significantly higher than those treated with simple hydrogel ( P<0.05); the mortality rates of Escherichia coli and Staphylococcus aureus treated with composite hydrogel+light irradiation were significantly higher than those treated with composite hydrogel alone ( P<0.05). After 24 h of culture, compared with that cultured in composite hydrogel immersion solution with final mass concentration of 0 mg/mL, the proliferation activity of HFbs cultured in composite hydrogel immersion solution with final mass concentrations of 25.0 and 50.0 mg/mL was significantly enhanced ( P<0.05), while the proliferation activity of HFbs cultured in composite hydrogel immersion solution with final mass concentration of 100 mg/mL was significantly decreased ( P<0.05). On PID 0 and 3, more purulent secretions were seen in the wounds of mice in blank control group and simple hydrogel group, while only a small amount of exudate was observed in the wounds of mice in composite hydrogel group, and no obvious infection was observed in the wounds of mice in combined treatment group. On PID 7 and 14, the wound healing rates of mice in simple hydrogel group were significantly higher than those in blank control group ( P<0.05); the wound healing rates of mice in composite hydrogel group were significantly higher than those in simple hydrogel group ( P<0.05); the wound healing rates in combined treatment group were significantly higher than those in composite hydrogel group ( P<0.05). On PID 14, the wounds of mice in blank control group exhibited a high infiltration of inflammatory cells with no new epithelial layer observed; the wounds of mice in simple hydrogel group displayed a short length of newly formed epithelium with a small amount of inflammatory cells; the wounds of mice in composite hydrogel group exhibited continuous formation of new epithelium and a large amount of immature granulation tissue; the wounds of mice in combined treatment group showed continuous epithelialization with less immature granulation tissue. Conclusions:The prepared composite hydrogel exhibits excellent thermosensitivity, photothermal properties, and injectability, as well as excellent mechanical properties, antibacterial properties, and biocompatibility, and can promote the healing of infected full-thickness skin defect wounds in mice.

Objective:To analyze current situation of hospice care in Jinshan District of Shanghai and provide recommendations for development of hospice care. Methods:This cross-sectional study included 8 hospice care institutions， their health staff and 316 patients during May-August， 2019. Results were analyzed by quantitative and qualitative methods. Results:There had 80 approved beds in Jinshan District， but only 53 beds were used for 189 inpatients in 2017. Hospice care institutions received financial supports from district government at the construction stage， but relied on their own for daily operation costs. The motivation of health staff to work in hospice care was not strong. Among the hospice care workers， 18% had no certification for hospice care， and only 5% of them had senior professional titles. Continued education for health workers in hospice care was weak and the workers were under heavy stress. Conclusion:The potential needs for hospice care were unmet while hospice care was under-utilization in Jinshan District. The development of hospice care was unbalanced， and the health workers lacked motivation. The resources of hospice care need to be strengthened.