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Objective To prepare thermosensitive chitosan (CTS) hydrogels containing astragalus polysaccharides (APS)/CTS microshperes (MS), and evaluate its physicochemical properties. Methods The APS/CTS MS (APS-MS) were prepared by spray drying method, and characterized by Scanning Electron Microscopy (SEM) and Laser Granularity Analyzer. Depending on the gelation temperature and gelating time, thermosensitive CTS hydrogels (HG) containing APS-MS (APS-MS-HG) were optimized by signal factor experiments, and the morphological characteristics were observed by SEM. In vitro release behaviors of APS-MS, hydrogels containing APS (APS-HG) and APS-MS-HG in pH 6.8 phosphate buffer were evaluated by dialysis tube method. Results The APS-MS were well dispersed with nearly spherical shapes and slightly wrinkled surfaces. The surface weighted mean D[3,2] of APS-MS was 8.078μm. The optimal APS-MS-HG, APS-MS-HG J, contained 3.012% APS-MS which were agitated with a magnetic stirrer for 3h. Observed by SEM, APS-MS were stayed spherical and dispersed unevenly in HG J, but the porous structure of HG J was disappeared in APS-MS-HG J. The release of APS from APS-MS-HG J was without initial burst release, and the cumulative amount of APS was about 74.75% after 36h. Conclusion Suppressing the phenomenon of sudden release at the first stage of delivery, APS-MS-HG J holds great promise for topical applications as a sustained-release nasal delivery system.
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Objective To construct the drug delivery system of gentamicin/chitosan microspheres for local injection, and evaluate its physicochemical properties and cell cytotoxicity.Methods Gentamicinwas used as model drug, chitosan as carrier, lecithinand hydroxypropyl-β-cyclodextrin as accessories, and the microspheres of gentamicin/chitosan/lecithin/hydroxypropyl-β-cyclodextrinwas prepared by spray drying method.The physicochemical properties and cell cytotoxicity of themicrospheres were investigated by UV spectrophotometry , scanning electron microscopy, X-ray diffraction, dynamic membrane dialysis and MTT assay.Results Five kinds of chitosan microspheres ( A, B, C, D and E) with different drug/carrier ratios were successfully prepared by spray drying method.The yield, drug loading and entrapment efficiency of the drug-loaded microspheres were 34.38%~46.94%, 10.20% ~18.67%, 61.20% ~74.72%, respectively.SEM results showed that compared with microspheres A, B and C, microspheres D and E own the spherical shape with wrinkled surface and uniform particle size, particle size between 0.5 ~3 μm, no adhesion.X-ray diffraction analysis showed that the drug was encapsulated in the microspheres.The results of in vitro release indicated that microspheres D had a good sustained release effect in the four drug-loaded microspheres.The results of cytotoxicity test showed that when the concentration of gentamicin reached 400 μg/mL, the relative growth rate of microspheres D was still higher than 80% with the cytotoxicity grade was one, ie, no cytotoxicity.Conclusion The microspheres D with good physicochemical properties, sustained-release effect and biocompatibility, is expected to be a good carrier of prostate local drug delivery.
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Objective To prepare quercetin ( QUE) loaded chitosan nanoparticles ( CS-NPs), evaluate its physicochemical properties and antioxidation activity in vitro.Methods Quercetin chitosan nanoparticles were prepared by ionic crosslinking method and self-assembly method.The preparation method was optimized using entrapment efficiency (EE), drug loading (DL) and size as indexes.The best formulation and preparation conditions were optimized by orthogonal test based on single-factor test, evaluation indicator as particle size and EE.The physicochemical properties of the obtained QUE-CS-NPs were characterized by the following methods: the transmission electron microscope (TEM), dynamic light scattering (DLS) analysis for morphology, size distribution and Zeta potential.In vitro release behavior in 0.5% SDS solution was evaluated by dialysis tube method.In vitro antioxidant activity assays were performed by evaluating the abilities of the microspheres for hydroxide radicals and superoxide anions .Results TEM results revealed QUE-CS-NPs with round and uniform.Particle-size analysis showed that the diameters and Zeta potential of the QUE-CS-NPs were (282.9 ±20) nm and (30.5 ±2) mV, with uniform distribution (polydispersity below 0.185).DL and EE of QUE-CS-NPs were (8.81 ±0.65) %and (80.02 ±1.04) %, respectively.QUE-CS-NPs showed extended administration times with 66.2% cumulative release within 72 h.QUE-CS-NPs showed pronounced antioxidant activity and a concentration dependent, even more substantial than that of pure QUE.Conclusion QUE-CS-NPs show a good size, sustain release effect and pronounce antioxidant activity.
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Objective To investigate the effects of astragalus polysaccharides on radio-pulmonary lesion.Methods 48 Wistar rats were divided into normal group, model group, astragalus polysaccharides treated group and dexamethasone treated group, each had 12 rats.Models of radio-pulmonary lesion of rats in later three groups were established by whole-thorax irradiation 20 Gy, then normal group was pretending to irradiation.Rats in normal group and model group were given 0.9% NaCl, astragalus polysaccharides treated group and dexamethasone treated group were given astragalus polysaccharides(8mg/mL) and dexamethasone(0.05mg/mL), accordingly.All rats were with 8 weeks, at 2 w and 8 w post-injury, 6 rats in each group were selected randomly and anesthesia to death.The erythrocytes and leukocytes in blood and bronchoalveolar lavage fluid ( BALF) in each group were detected and histological examination of lung tissues were performed by Haematoxylin and Eosin staining to study general morphology.Results Radiation-induced lung injury rat model were successfully constructed, general observation showed that irradiated rats gradually appear listlessness, reduce the volume of activities, arched, hair removal and other symptoms, astragalus polysaccharide (APS) and dexamethasone treated rats had gradual improvement than model group.Compared with control group, erythrocytes and leukocytes counts in serum of model group at 2 w and 8 w post-injury were significantly decreased(P <0.05), the numbers of erythrocytes and leukocytes in BALF were significantly increased(P <0.05). Compared with model group group, the leukocytes, erythrocytes and neutrophils counts in serum of astragalus polysaccharides treated group and dexamethasone treated group were all increased(P <0.05), respectively, and the number of leukocytes and erythrocytes in BLAF were significantly decreased(P<0.05).All the indexes between two groups had no significant difference.The pathological changes of lung tissues showed that rats in model group had rupture alveolar wall, widened alveolar interval, pulmonary interstitial hyperplasia, and the alveolar space and interstitial lung stroma had a large number of inflammatory cells exudation.The symptoms in astragalus polysaccharides treated group and dexamethasone treated group were all alleviated, and there was no significant difference between the two groups.Conclusion Astragalus polysaccharides have therapeutic effect on radio-pulmonary lesion in rats, and the therapeutic effects of astragalus polysaccharides are roughly similar to dexamethasone.Further research is needed to elucidate the mechanism behind the effects of astragalus polysaccharides in order to develop appropriate treatment.
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Objective To prepare proanthocyanidins/bletilla striata polysaccharide/chitosan microspheres ( PC/BSP/CTS ) and the physic-chemical characterizations were investigated.Methods The PC/BSP/CTS microspheres were prepared by spray drying method.The morphology of PC/BSP/CTS microspheres was observed by Scanning Electron Microscopy(SEM), and its physic-chemical characteristics such as diameters, release in vitro, moisture content, swelling ratio, solid density were studied.ResuIts The PC/BSP/CTS microspheres were successfully prepared by spray drying method, SEM showed that PC/BSP/CTS microspheres had the spherical shape with smooth surfaces.The diameters of microsphere A, B and C were 10~20, 2~15, 10~25μm.The in-vitro release showed that the cumulative release of three kinds of microspheres A, B, C was 25.07 %, 38.83 %and 60.00 % in 24 h, which had no burst release, while with time prolonged to 48 h, the cumulative release was 28.89%, 43.17% and 72.86%, respectively.The results of moisture content, swelling ratio, solid density were 15.35% ~23.51%, 46.50% ~105.80%, 0.375 ~0.496. ConcIusion The PC/BSP/CTS microspheres are successfully prepared by spray drying method which possess good characteristics and sustained-release effect, which would be as a good pulmonary drug delivery system.
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BACKGROUND:The patients are suffering from peritoneal adhesions that are caused after abdominal operation. As so far, there is stil no effective drug or method that can completely prevent peritoneal adhesions. Carboxymethyl chitosan is a biocompatible and biodegradable biomedical material with anti-adhesion effects, which is an ideal biomaterial for prevention of peritoneal adhesion theoreticaly. OBJECTIVE:To investigate the novel anti-adhesion properties of carboxymethyl chitosan anti-adhesion solution on the prevention of postsurgical adhesion in vivo in a rat model. METHODS:Fifty-six adult male Wistar rats were randomly divided into four groups: 0.9% normal saline solution (group A), hyaluronic acid gels (group B), medical chitosan gels (group C) and carboxymethyl chitosan anti-adhesion solution (group D). The model of postoperative intestinal adhesion was established by making cecal scratches/abdominal wal defects. Al the rats were scarified after 2 or 3 weeks. Whole blood was colected by cardio-puncture, lung tissue and tissue adhesion were stripped. The incidence and degree of adhesions, histological effects, expression of transforming growth factor-β1 (TGF-β1), the amounts of hydroxyproline and white blood cels were observed. RESULTS AND CONCLUSION:The formation of postsurgical adhesions in groups B, C and D was significantly decreased, which was lighter than that of group A (P < 0.05). Furthermore, the adhesion formation in group D was significantly decreased in comparison with group A (P < 0.01). At the same time, the levels of transforming growth factor-β1, hydroxyproline and white blood cels in group D were lighter than those of group A (P < 0.05), and the histopathological results indicated that a marked reduction in inflammatory cels and fibroblasts. Carboxymethyl chitosan anti-adhesion solution can effectively reduce the degree and incidence of postoperative adhesion, and it is becoming a promising drug delivery system in the context of postsurgical anti-adhesion.
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Aim To investigate the effect of PLK1 on epithelial-mesenchymal transition (EMT)of human e-sophageal squamous cell carcinoma (ESCC)cells TE-1 5 and its relevant molecular mechanisms.Methods PLK1 overexpressed ESCC cells and control vector were used as the experimental cells.The expression of EMT-related protein markers E-cadherin and vimentin were measured by Western blot.vimentin mRNA was measured by Real-time PCR.Total cellular protein and nuclear protein were respectively extracted,and then they were used to detect the expression of β-catenin by Western blot.β-catenin siRNA and non-specific siR-NA were transiently transfected into the cell clones overexpressed PLK1 ,and then vimentin was detected by Western blot.β-catenin protein degradation com-plex was detected by immunoprecipitation and Western blot.Results The mesenchymal marker vimentin was distinctively upregulated and the epithelial marker E-cadherin was distinctively downregulated in the cell clones overexpressed PLK1 ,compared with those in the vector clones.This indicated that EMT occurred in ESCC cells.vimentin mRNA was also markedly in-creased.In the cell clones overexpressed PLK1 ,β-catenin were both elevated from the total cells and the nucleus.The expression of vimentin was reduced whenβ-catenin was knocked down.APC and GSK-3βwere both reduced from Axin immunoprecipitate in the cell clones overexpressed PLK1 .Conclusion PLK1 up-regulates vimentin and promotes EMT in ESCC cells probably by inhibiting the formation of protein degrada-tion complex and stabilizing β-catenin.
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<p><b>OBJECTIVE</b>To study the change of synaptic onset latency and threshold in primary auditory cortex (A1) during the development of SD rat.</p><p><b>METHODS</b>Extracellular recording was used to locate A1, followed by transferred to loose-patch and whole-cell patch in vivo to record the spike activity, synaptic onset latency and threshold responses respectively. Rats were divided into 4 groups according to ages, postnatal 12-15 days, 16-18 days, 19-24 days and adult (> 3 months).</p><p><b>RESULTS</b>1. The onset latency of local field potential in A1 of adult rats[(10-20)ms] was shorter than young rats[(20-30)ms]. 2. During development, the onset latency of spikes of a single neuron in response to white noise pulses decreased. And the latency in young rats P12-15 [(40.15 ± 2.67) ms] and P16-18 [(33.86 ± 4.61) ms] were longer than in adults [(22.93 ± 2.94) ms] (ANOVA-test, t = 4.330 and 1.995, P = 0.00 and 0.04) . However, the onset latencies of P19-24 [(24.80 ± 3.63) ms] and adult had no significant difference (P > 0.05). 3.Synaptic onset latencies of both excitation and inhibition were significantly longer in P12-15[ (38.94 ± 1.90) ms, (35.26 ± 2.40) ms] and P16-18[ (32.68 ± 2.52) ms, (30.24 ± 2.18) ms] than in adults [(19.4 ± 1.06) ms, (18.91 ± 0.77) ms] excitation (t = 6.255 and 4.662, P < 0.01) inhibition (t = 8.918 and 4.820, P < 0.01) showed significant difference. Whereas the onset latencies of P19-24[ (23.67 ± 2.46) ms, (21.43 ± 1.80) ms] and adults displayed no prominent difference(P > 0.01). Meanwhile, the difference between the onset latencies of excitation and inhibition became narrower during development[ (3.15 ± 1.02) ms, (2.01 ± 0.73) ms, (1.79 ± 0.85) ms, (0.39 ± 0.48) ms]. P12-15 had notably difference in comparison to adults (t = 1.739, P < 0.01). 4. The thresholds of synaptic response were notably higher in P12-15 (40.0 ± 1.6) dB and P16-18 (41.3 ± 11.6) dB when compared with adults (30.9 ± 0.6) dB (t = 5.284 and 5.867, P < 0.01) . While that of P19-24 (35.0 ± 32.7) dB showed no distinct difference (P > 0.01).</p><p><b>CONCLUSION</b>Single neuron spiking activity, synaptic onset latency and threshold evoked by sound stimulus gradually mature during the development in rat A1.</p>