A multiple-stimuli-responsive drug-conjugated cross-linked micelles was prepared by radical copolymerization. The chemical structure, morphology, and size of the cross-linked micelles were characterized, and the drug loading of the micelle was calculated. The experimental results indicated that the hydrodynamic size of the drug-loaded micelles were about 100 nm, and the as prepared micelles could be degraded and swelled in presence of reducing glutathione (GSH). The low critical solution temperature (LCST) of the micelle was around 39.4℃. According to the experimental results, the micelles will shrink at temperature above the LCST. Subsequently, the accumulative drug release rate was up to 91.78% under acidic (pH 5.0), reductive (GSH 10 mmol/L) and high temperature (42.0℃) conditions mimicking the tumor microenvironment, while a relatively low release rate of 1.12% was observed without stimulation. The drug-conjugated cross-linked micelles showed a strong cell uptake behavior. In the cytotoxicity assay, the micelles exhibited effective anti-cancer activity and excellent biocompatibility. In brief, the experimental results show that the as-prepared drug-conjugated cross-linked micelle exhibits multiple stimuli-responsiveness, which holds great promise for anti-cancer drug delivery.
Objective To investigate the intervention effect of 3-phosphoinositede dependent protein kinase-1 (PDK1) inhibitor on prostaglandin E2 (PGE2) in smoking-induced chronic obstructive pulmonary disease (COPD) mice. Methods Fifty C57BL/6 male mice were randomly divided into normal control group, smoking group, smoking +low dose PDK1 inhibitor group, smoking + medium dose PDK1 inhibitor group and high dose PDK1 inhibitor group with 10 mice in each group. The mice in the normal control group inhaled phosphate-buffered saline twice a day for 12 weeks, and the mice in the smoking group were fumigated twice a day, 5 days per week for 12 weeks, and the other three groups were given intraperitoneal injection of low-dose PDK1 inhibitor OSU-03012 (0.25 mg/kg), medium-dose PDK1 inhibitor (0.5 mg/kg) and high-dose PDK1 inhibitor (1.0 mg/kg) respectively before smoking. After smoking, lung function was tested, the bronchoalveolar lavage fluid (BALF) of each mouse was taken for cell count, the PGE2 in serum and BALF of mice was determined by enzyme linked immunosorbent assay, and the lung tissue of mice was sectioned with paraffin and stained by hematoxylin-eosin (HE), and pathological changes were observed under microscope. Results Compared with the control group, FEV100/FVC and FEV200/FVC of the mice in each smoking group were significantly decreased (P<0.05); The number of cells in BALF of smoking group was significantly higher than that of normal control group (P<0.05). There was no significant difference in the total number of BALF cells, the proportion of neutrophils and macrophages between the smoking + low-dose PDK1 inhibitor group and the smoking group. However, the total number of BALF cells and the proportion of neutrophils in the smoking + medium dose PDK1 inhibitor group and the high dose PDK1 inhibitor group gradually decreased, while the proportion of macrophages gradually increased, compared with the normal control group, the PGE2 concentrations of serum and BALF in the smoking group and the smoking + PDK1 inhibitor group were significantly higher than those in the control group. Compared with the smoking group, the PGE2 concentrations of serum and BALF in the middle and high dose PDK1 inhibitor groups were significantly lower than those in the smoking group. HE staining of lung tissue showed that there were a large number of inflammatory cell infiltration, alveolar cavity dilatation, alveolar wall rupture and fusion, alveolar formation, significant decrease in the number of alveoli and other pathological changes in the smoking group, which were consistent with the pathological changes of COPD. The inflammatory cell infiltration, mucus obstruction and alveolar dilatation were slightly alleviated in the smoking + low-dose PDK1 inhibitor group, while the inflammatory cell infiltration, alveolar wall thinning and alveolar dilatation were improved in both the medium-dose inhibitor group and the high-dose inhibitor group, and the improvement was more obvious in the high-dose inhibitor group. Conclusion The lung function of the smoked COPD mouse decreases, the airway inflammation is obvious, and the secretion of PGE2 is also increased, while the use of PDK1 inhibitor could reduce the secretion of PGE2, reduce airway inflammation and pathological changes, and improve lung function in a dose-dependent manner.
Objective The human amniotic epithel ial cells (hAECs) are a recently identified new type of stem cells.It has previously been shown that hAECs express hepatocyte-related gene and possess intracellular features and functional properties of hepatocytes. The hAECs may be a candidate seed cell for l iver regeneration. To research the survival and migrationin vivo of hAECs via adeno-associated virus-mediated the green fluorescent protein gene (AAV-GFP) transfection, and toexplore the expression of hepatocyte-l ike function. Methods Thirty nude mice (aging 6-8 weeks, half males and females, and weighing 20-22 g) were randomly divided into 3 groups (groups A, B, and C, n=10). The mice of groups A and C were made the 2/3 partial hepatectomy model, and the mice of group B underwent open abdominal operation without hepatectomy. The hAECs transfected by AAV-GFP were transplanted into the inferior end of the spleen in groups A and B with a cell density of 5 × 106/mL and a volume of 0.2 mL; the same volume of normal sal ine was injected in group C. At 4 hours, the nude mice were sacrificed and the samples of l iver, spleen, heart, lung, brain, and kidney were harvested and the general observation, histological observation, and immunofluorescence detection were performed for the hAECs survival, migration, and the functional properties of hepatocytes. Results No tumor tissue was found in l iver and spleen of 3 groups, and HE staining showed no tumor cells. There were a lot of roundl ike and deeply-stained cells with less cytoplasm and large nucleus in the spleen and the l iver of group A; no abnormal cells were found in l iver and spleen of groups B and C and in kidney, heart, bung, and brain of groups A, B, and C. The GFP+ cells were detected in the spleen and l iver of group A with expressing human albumin, but no GFP+ cells was found in l iver and spleen of groups B and C and in heart, kidney, lung, and brain of groups A, B, and C. Conclusion AAV-GFP infected hAECs transplanted into SCID nude mice with hepatectomy can keep the hepatocyte-l ike function. It will be beneficial to further identify their biological characteristics.
Objective
To investigate the effect of human placental-derived mesenchymal stem cells (PMSCs) on immunological rejection in mouse allogeneic skin transplantation.
Methods
The placenta fetal tissues from voluntary donors were used to isolate and culture the PMSCs, and the 3rd passage PMSCs were used in the experiment. Thirty Vr
∶
CD1 (ICR) mice at age of 1-2 days were used as skin donors for allogeneic skin transplantation. Thirty C57BL/6 mice at age of 6-8 weeks as recipients were made back skin defect of 12 mm in diameter and were randomly divided into 3 groups (n=10): group A, autograft; group B, allogeneic graft + PBS tail vein injection; and group C, allogeneic graft + human PMSCs (1 × 105 cells/mouse) tail vein injection. The flap survival was observed. At 7 days after skin transplantation, blood leukocyte counting, abdominal fluid macrophage activation, and the expression levels of interleukin 4 (IL-4), interleukin 17 (IL-17), and interferon γ (INF-γ) in blood and spleen were detected by ELISA and RT-PCR, respectively.
Results
The flap survival time was significantly longer in group A [(58.33 ± 4.04) days] than in groups B and C [(3.80 ± 0.92) days and (6.80 ± 0.82) days] (P lt; 0.05), and in group C than in group B (P lt; 0.05). At 7 days after transplantation, the blood leukocyte number was (6.32 ± 0.45) × 109/L in group A, (7.45 ± 0.52) × 109/L in group B, and (6.35 ± 0.39)× 109/ L in group C, and it was significantly more in group B than in groups A and C (P lt; 0.05). The macrophage activation rate of the abdominal fluid was 6.87% ± 2.40% in group A, 7.84% ± 0.44% in group B, and 15.98% ± 2.87% in group C; group C was significantly higher than groups A and B (P lt; 0.01). ELISA results showed that there was no significant difference in the concentrations of IL-4 among 3 groups (P gt; 0.05). Compared with group B, the concentrations of IL-17 and IFN-γ were significantly reduced in group C (P lt; 0.05), while the concentration of IFN-γ was significantly increased in group B when compared with group A (P lt; 0.05). RT-PCR results showed that there were significant differences in the expressions of IL-4, IL-17, and IFN-γ mRNA between groups B, C and group A (P lt; 0.05); the expressions of IL-4 and IFN-γ mRNA were significantly lower in group C than in group B (P lt; 0.05).
Conclusion
Human PMSCs transplantation can suppress the acute immunological rejection in allogeneic skin transplantation. The possible mechanism may be partially related to the inhibitory effect on the secretion of IL-17 and IFN-γ.
ObjectiveTo discuss the effects of coix seed extract injection on rate of tumor of C57 mice liver cancer model, tumor size, and serum IL-6.
MethodsUsing chemical carcinogens diethyl nitrosamine (DEN) to establish the mice model of liver cancer, liver cancer mouse model to coix seed extract was given observation of C57 mice liver cancer model come tumor formation rate, tumor growth, and the change of serum IL-6.
ResultsC57 mice after intraperitoneal injection of coix seed extract injection model of liver cancer tumor rate (55.6%) significantly lower than the DEN group (87.5%), P < 0.01; tumor diameter[(0.3±0.05) cm] was lower than that in group DEN[(0.8±0.06) cm], P < 0.01. The serum level of IL-6 in C57 mice after treated with coix seed extract significantly lower than that in group DEN (P < 0.01).
ConclusionCoix seed extract can effectively inhibit the tumor rate and the growth of tumor in hepatocellular carcinoma model of C57 mice, and decrease the level of serum IL-6.
ObjectiveTo explore the endothelial cells from human peripheral blood and islet of rat co-transplantation under the renal capsule of diabetic nude mice to improve the survival and function of transplanted islet.
MethodsThe endothelial cells from human peripheral blood(5×105)and freshly isolated rat islet cells were co-transplanted under the renal capsule of diabetic nude mice model, then the fasting blood glucose, body weight, peripheral blood C-peptide level, and intraperitoneal glucose tolerance test(IPGTT) were measured to evaluated the islet graft survival and function.
ResultsCompared with the control group, the fasting blood glucose level significantly decreased(P < 0.01), peripheral blood C-peptide level rised(P < 0.01), and body weight increased(P < 0.01) of receptor nude mice in experience group, the IPGTT also improved.
ConclusionThe endothelial cells from human peripheral blood and islet of rat co-transplan-tation can obviously improve the survival and function of transplanted islet of nude mice.
Objective
To investigate how to establish stable mice cervical heart transplantation model.
Methods
Totally, 40 male C57 mice with the age of 6-8 weeks and weight of 19-24 g were randomly divided into recipients and donors (n=20 in each group). Mice cervical heart transplantation model was established by connecting the ascending aorta of donors to the right cervical common artery of recipients through end to side anastmosis and the pulmonary artery of donors to the right external jugular vein of recipients through end to end anastmosis.
Results
More than 95% recipients survived after surgery. Cold ischemia time was 15±5 min, warm ischemia time 23±6 min, and the whole operation took about 55±15 min. The recipients survived more than 30 d with functional heart grafts. Histologically, there was no difference between the heart graft one month after the transplantion and the normal heart.
Conclusion
Cervical heart transplantation of mice model is reliable and feasible, which is easy to monitor the survival condition of heart graft by visual examination and palpation, which will benefit the basic research in transplantation field.
Objective To study the expressions of human ether-a-go-go related gene (HERG) in CD1 mice gallbladder and interstitial cells of Cajal (ICC) and explore their possible implications. Methods The expression of HERG protein in gallbladder tissue slices obtained from CD1 mice was detected by immunohistochemistry method. The expression of HERG mRNA in gallbladder tissue was detected by reverse transcription (RT)-PCR. The production of HERG protein was confirmed in the CD1 mice gallbladder by Western blot. Enzymatically dispersed cells were identified as ICC using the specific ICC marker c-kit antibody, and the double positive cells of c-kit and HERG were observed by laser passing confocal microscope. Results HERG was present in the CD1 mice gallbladder tissues for the yellow or buffy positive reaction. At the same time, the expression of mRNA specific for the HERG gene and production of HERG protein in the CD1 mice gallbladder tissues were indicated by RT-PCR and Western blot analysis, respectively. Using double labeling of anti-c-kit and anti-HERG, the double positive cells of c-kit and HERG were observed in the CD1 mice ICC by laser passing confocal microscope. Conclusion The study demonstrates that HERG is present in the CD1 mice gallbladder tissues and ICC, which is likely related to the pacemaking activity of ICC.
【Abstract】 Objective To investigate the impact of dermal papillary cells on vascularization of tissue engineered skinsubstitutes consisting of epidermal stem cells and allogeneic acellular dermal matrix. Methods Human foreskins from routinecircumcisions were collected to separate epidermal cells by using dispase with trypsogen. Collagen type IV was used to isolateepidermal stem cells from the 2nd and 3rd passage keratinocytes. Dermal papilla was isolated by the digestion method of collagenaseI from fetus scalp and cultured in routine fibroblast medium. Tissue engineered skin substitutes were reconstructed by seedingepidermal stem cells on the papillary side of allogeneic acellular dermis with (the experimental group) or without (the controlgroup) seeding dermal papillary cells on the reticular side. The two kinds of composite skin substitutes were employed to cover skindefects (1 cm × 1 cm in size) on the back of the BALB/C-nu nude mice (n=30). The grafting survival rate was recorded 2 weeks aftergrafting. HE staining and immunohistochemistry method were employed to determine the expression of CD31 and calculate themicrovessel density at 2 and 4 weeks after grafting. Results Those adhesion cells by collagen type IV coexpressed Keratin 19 andβ1 integrin, indicating that the cells were epidermal stem cells. The cultivated dermal papillary cells were identified by expressinghigh levels of α-smooth muscle actin. The grafting survival rate was significantly higher in experimental group (28/30, 93.3%), thanthat in control group (24/30, 80.0%). HE staining showed that the epithelial layer in experimental group was 12-layered with largeepithelial cells in the grafted composite skin, and that the epithelial layer in control group was 4-6-layered with small epithelial cells.At 2 and 4 weeks after grafting, the microvessel density was (38.56 ± 2.49)/mm2 and (49.12 ± 2.39)/mm2 in experimental group andwas (25.16 ± 3.73)/mm2 and (36.26 ± 3.24)/mm2 in control group respectively, showing significant differences between 2 groups(P lt; 0.01). Conclusion Addition of dermal papillary cells to the tissue engineered skin substitutes can enhance vascularization,which promotes epidermis formation and improves the grafting survival rate.
Objective To establish a xenograft model of hydroxycamptothecine (HCPT)-resistant human gastric cancer cell line (SGC-7901/HCPT) in nude mice and study its biological characteristics. Methods The SGC-7901 and SGC-7901/ HCPT cells were cultured in vitro. The cell suspension was injected subcutaneously into the nude mice. When the subcutaneous carcinoma was 1.0 cm in diameter, it was cut off and divided into pieces of 0.1-0.2 cm in diameter． Then the small pieces of tumor were re-transplanted subcutaneously into the second generation nude mice until the fourth generation. The morphological feature, ultramicro-structure, and growth characteristics of the fourth generation transplanted tumor were examined. The drug resistance was measured by methyl thiazolyl tetrazolium (MTT) assay. Results The transplanted tumor in nude mice was round or oval, and many blood vessels were on its surface. Under the light microscope, the sizes of SGC-7901 transplanted tumor cells were similar, and sizes of cell nuclei were also similar; Meanwhile, the morphous of SGC-7901/HCPT transplanted tumor cells were irregular and in disorder, and the size of the cell nuclei was different from each other. Under the electron microscope, the mitochondria and endoplasmic reticulum of SGC-7901 transplanted tumor cells were nearly normal and no swelling in cell nuclei; Meanwhile the cell nuclei of SGC-7901/HCPT transplanted tumor cells were lightly swelled, a the mitochondria and endoplasmic reticulum were obviously swelled. By MTT assay, compared with SGC-7901 transplanted tumor cells, the resistance index of SGC-7901/HCPT transplanted tumor cells was 9.02±0.78 in HCPT, and resistance index to Adriamycin， Mitomycin C, 5-fluorouracil, and Etoposide was 1.24±0.09, 1.31±0.17, 0.96±0.12, and 1.07±0.16, respectively. Conclusions A transplanted tumor model of SGC-7901/HCPT in nude mice is established successfully， and showing stable drug resistance to HCPT and no cross-resistance to other chemotherapeutics, which can be used for further experiments.
