A pH-Sensitive Polymeric Micellar System Based on Chitosan Derivative for Efficient Delivery of Paclitaxel.

In this study, an amphiphilic conjugate based on mPEG and cholesterol-modified chitosan with hydrazone bonds in the molecules (mPEG-CS-Hz-CH) was successfully synthesized. Using the polymer as the carrier, the paclitaxel (PTX)-loaded mPEG-CS-Hz-CH micelles were prepared by an ultrasonic probe method. The mean particle size and zeta potential of the optimized PTX-loaded micelles were 146 ± 4 nm and +21.7 ± 0.7 mV, respectively. An in vitro drug release study indicated that the PTX-loaded mPEG-CS-Hz-CH micelles were stable under normal physiological conditions (pH 7.4), whereas rapid drug release was observed in the simulated tumor intracellular microenvironment (pH 5.0). An in vitro cytotoxicity study demonstrated the non-toxicity of the polymer itself, and the PTX-loaded micelles exhibited superior cytotoxicity and significant selectivity on tumor cells. An in vivo antitumor efficacy study further confirmed that the PTX-loaded micelles could improve the therapeutic efficacy of PTX and reduce the side effects. All these results suggested that the mPEG-CS-Hz-CH micelles might be promising pH-sensitive nanocarriers for PTX delivery.

Polymeric Micelles Based on Modified Glycol Chitosan for Paclitaxel Delivery: Preparation, Characterization and Evaluation.

Amphiphilic polymer of α-tocopherol succinate modified glycol chitosan (TS-GC) was successfully constructed by conjugating α-tocopherol succinate to the skeleton of glycol chitosan and characterized by Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). In aqueous milieu, the conjugates self-assembled to micelles with the critical aggregation concentration of 7.2 × 10−3 mg/mL. Transmission electron microscope (TEM) observation and dynamic light scattering (DLS) measurements were carried out to determine the physicochemical properties of the micelles. The results revealed that paclitaxel (PTX)-loaded TS-GC micelles were spherical in shape. Moreover, the PTX-loaded micelles showed increased particle sizes (35 nm vs. 142 nm) and a little reduced zeta potential (+19 mV vs. +16 mV) compared with blank micelles. The X-ray diffraction (XRD) spectra demonstrated that PTX existed inside the micelles in amorphous or molecular state. In vitro and in vivo tests showed that the PTX-loaded TS-GC micelles had advantages over the Cremophor EL-based formulation in terms of low toxicity level and increased dose, which suggested the potential of the polymer as carriers for PTX to improve their delivery properties.

Multifunctional Composite Microcapsules for Oral Delivery of Insulin.

In this study, we designed and developed a new drug delivery system of multifunctional composite microcapsules for oral administration of insulin. Firstly, in order to enhance the encapsulation efficiency, insulin was complexed with functional sodium deoxycholate to form insulin-sodium deoxycholate complex using hydrophobic ion pairing method. Then the complex was encapsulated into poly(lactide-co-glycolide) (PLGA) nanoparticles by emulsion solvent diffusion method. The PLGA nanoparticles have a mean size of 168 nm and a zeta potential of -29.2 mV. The encapsulation efficiency was increased to 94.2% for the complex. In order to deliver insulin to specific gastrointestinal regions and reduce the burst release of insulin from PLGA nanoparticles, hence enhancing the bioavailability of insulin, enteric targeting multifunctional composite microcapsules were further prepared by encapsulating PLGA nanoparticles into pH-sensitive hydroxypropyl methyl cellulose phthalate (HP55) using organic spray-drying method. A pH-dependent insulin release profile was observed for this drug delivery system in vitro. All these strategies help to enhance the encapsulation efficiency, control the drug release, and protect insulin from degradation. In diabetic fasted rats, administration of the composite microcapsules produced a great enhancement in the relative bioavailability, which illustrated that this formulation was an effective candidate for oral insulin delivery.

Design and fabrication of chitosan-based AIE active micelles for bioimaging and intelligent delivery of paclitaxel.

In this study, cetyl 4-formylbenzoate alkyl and 4-(2-hydroxyethoxy) benzophenonesalicylaldazide modified biotinylated chitosan (CS-BT-HBS-CB) featured with aggregation-induced emission (AIE) characteristic, active tumor-targeting ability and pH-responsive drug release property was designed and synthesized. The polymer was fabricated by introducing hydrophobic segment, tumor targeting ligand, acid-sensitive bond and AIE fluorophore to the backbone of chitosan. Due to its amphiphilicity, the polymer could self-assemble into micelles and encapsulate paclitaxel (PTX) to form PTX-loaded CS-BT-HBS-CB micelles. The mean size of the micelles was 167 nm, which was beneficial to the EPR effect. Moreover, with the help of above functional groups, the micelles exhibited excellent AIE effect, triggered drug release behavior by acidic condition, selective internalization by MCF-7 cells and excellent cellular imaging capability. In vivo studies revealed that the PTX-loaded CS-BT-HBS-CB micelles could enhance the antitumor efficacy with low systemic toxicity. This micellar system would be a potential candidate for cancer therapy and bioimaging.

Impact of 11q Loss of Heterozygosity Status on the Response of High-Risk Neuroblastoma With MYCN Amplification to Neoadjuvant Chemotherapy.

Purpose: The aim of this study was to investigate whether 11q loss of heterozygosity (LOH) aberration would impact the response of the primary tumor to neoadjuvant chemotherapy or to the degree of surgical resection in neuroblastoma (NB) patients with MYCN amplification. Methods: The clinical data of 42 NB patients with MYCN amplification who were newly diagnosed and received treatments at our hospital from 2011 to 2020 were retrospectively analyzed. According to the results of the segmental chromosome aberration analysis, the patients enrolled were assigned to an 11qLOH positive group and an 11qLOH negative group. Results: There was no significant difference in the mean number of chemotherapy courses completed before surgery between the 11qLOH positive and 11qLOH negative groups (p = 0.242). Each of the 42 patients had metaiodobenzylguanidine (MIBG) scans both before and after neoadjuvant chemotherapy. The percentage of patients who had a clinical MIBG change in the 11qLOH positive group was lower than the percentage in the 11qLOH negative group (27.27 vs. 66.67%, p = 0.030). The 11qLOH negative group seemed to have a higher rate of surgical resection (≥90%); however, the difference between the two groups was not statistically significant (p = 0.088). Furthermore, the 11qLOH negative group did not show significantly superior event-free survival and overall survival rates compared with the 11qLOH positive group. Conclusions: This study showed that patients with NB and MYCN amplification in combination with 11qLOH might be less likely to respond to neoadjuvant chemotherapy when compared with patients with NB and MYCN amplification without 11qLOH.

AIE-active polymeric micelles based on modified chitosan for bioimaging-guided targeted delivery and controlled release of paclitaxel.

In this study, a novel polymer based on aggregation-induced emission (AIE) fluorogen, biotin and disulfide bonds modified chitosan (TPE-bi(SS-CS-Bio)) was designed and synthesized. The polymer could self-assemble into micelles in aqueous media and encapsulate paclitaxel (PTX) into the core with high drug loading. Fluorescence study indicated that the micelles exhibited excellent AIE feature with intense blue fluorescence emitted. In vitro drug release study indicated that the micelles could disassemble rapidly in the presence of high level of glutathione. The modification by biotin could enhance the cellular uptake of the micelles. The drug-loaded micelles possessed remarkable cytotoxicity against MCF-7 cells, and their distribution in the cells could be traced due to the excellent AIE feature. In vivo antitumor efficacy study demonstrated the superior antitumor activity of the PTX-loaded TPE-bi(SS-CS-Bio) micelles. These results indicated that TPE-bi(SS-CS-Bio) has the ability of biological imaging and can be used as a potential carrier for PTX.

Quarantine at home may not enough!-from the epidemiological data in Shaanxi Province of China.

OBJECTIVES: A pneumonia associated with 2019 novel coronavirus (2019-nCoV, subsequently named SARS-CoV2) emerged worldwide since December, 2019. We aimed to describe the epidemiological characteristics of 2019 coronavirus disease (COVID-19) in Shaanxi province of China. RESULTS: 1. Among the 245 patients, 132 (53.9%) were males and 113 (46.1%) were females. The average age was 46.15 ± 16.43 years, ranging from 3 to 89 years. 2. For the clinical type, 1.63% (4/245) patients were mild type, 84.90% (208/245) were moderate type, 7.76% (19/245) were severe type, 5.31% (13/245) were critical type and only 0.41% (1/245) was asymptomatic. 3. Of the 245 patients, 116 (47.35%) were input case, 114 (46.53%) were non-input case, and 15 (6.12%) were unknown exposure. 4. 48.57% (119/245) cases were family cluster, involving 42 families. The most common pattern of COVID-19 family cluster was between husband and wife or between parents and children.

Synthesis, characterization, and cytotoxicity assessment of N-acetyl-l-cysteine capped ZnO nanoparticles as camptothecin delivery system.

The chemical stability, good biocompatibility and high drug loading capacity of zinc oxide nanoparticles (ZnO NPs) and their biomedical potentials make them a promising candidate for drug delivery. The aim of this study was to develop and assess a simple procedure for surface functionalization of ZnO NPs by N-acetyl-l-cysteine (NAC) for anticancer camptothecin (CPT) delivery. NAC capped ZnO NPs were successfully made using ZnCl2 and NaOH in the presence of NAC. CPT was covalently conjugated to the surface of as-synthesized ZnO-NAC NPs. To characterize the synthesized conjugate product (ZnO-NAC-CPT NPs), X-ray diffraction, Fourier Transform Infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and dynamic light scattering method were used. Our results indicated that the ZnO-NAC-CPT NPs exhibit near-spherical morphology and uniform dispersion with an average diameter of ∼70 nm. The hemolysis assay showed that ZnO-NAC-CPT NPs has almost no hemolytic activity. In addition, MTT cytotoxicity assessment on A549 lung cancer cells revealed a drop of IC50 values from 1.17 µg/mL (free CPT) to 0.66 µg/mL (ZnO-NAC-CPT NPs). This result showed an augmented cancer-inhibitory effect of nanoconjugate complex. In conclusion, the novel ZnO-NAC-CPT NPs could be considered for new therapeutic endeavors.

Tumor-targeting micelles based on folic acid and α-tocopherol succinate conjugated hyaluronic acid for paclitaxel delivery.

Tumor-targeting micelles for the delivery of paclitaxel (PTX) were developed based on folic acid and α-tocopherol succinate conjugated hyaluronic acid (FA-HA-TOS). The conjugate FA-HA-TOS was synthesized by an esterification reaction and was characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) analysis. The conjugate self-assembles into nanosized micelles in aqueous medium with a critical micellar concentration (CMC) of 1.12 × 10-2 mg/mL. The FA-HA-TOS micelles demonstrated high drug loading and entrapment efficiency for PTX, with respective values of 21.37% and 90.48%. The physicochemical properties of the micelles were measured by DLS, TEM and XRD. Moreover, in vitro and in vivo evaluations were performed to demonstrate the superior antitumor activity of the PTX-loaded micelles. It was suggested that the FA-HA-TOS micelle system represents a promising nanocarrier for targeted delivery of PTX.

[The delivery mechanism of micro-porous osmotic pump tablets].

To investigate the delivery mechanism of micro-porous osmotic pump tablets ( MPOP), taking tramadol hydrochloride ( TR) as the model drug, tramadol hydrochloride micro-porous osmotic pump tablets (TR MPOP) were prepared with compressible starch as diluent, cellulose acetate as coating material, polyethylene glycol 400 as pore-forming agents. The equilibrium solubility and osmolality of TR were determined. The effects of fillers in tablet cores, coating levels, and osmotic pressures of release media on expansion behavior of preparations were described. The influences of the category, osmolality, and pH value of release media, release methods, and release conditions on release curves of tablets were evaluated. Based on several models, the delivery pattern of TR MPOP was fitted. The equilibrium solubility in water and osmolality of TR were (775.8 +/- 17.7) g x L(-1) and 4.036 Osmol x kg(-1), respectively. During the drug-release period, it was observed that the tablets expanded markedly in response to the expansion characteristics of compressible starch and the osmotic pressure difference across the membrane. When osmotic pressure of release media increased, the significant change of the equilibrium solubility of TR was not found, but the release rates of TR MPOP decreased significantly. The delivery rate was not influenced by the pH of release mediums, dissolution methods and paddle stirring rates. The drug release profile conformed to the model of zero order in 8 h. The pore-forming agents were dissolved in release medium, which caused micro-pores. The expansion of tablets made the size of micropores bigger, and then the drug-releasing pores were obtained. It was proved that the drivers of drug delivering from TR MPOP were mainly the difference of osmotic pressure, and secondly the difference of solubility. TR MPOP were the controlled-release preparation.

Simultaneous Optimization of Multiple Response Variables for the Gelatin-chitosan Microcapsules Containing Angelica Essential Oil.

Angelica essential oil (AO), a major pharmacologically active component of Angelica sinensis (Oliv.) Diels, possesses hemogenesis, analgesic activities, and sedative effect. The application of AO in pharmaceutical systems had been limited because of its low oxidative stability. The AO-loaded gelatin-chitosan microcapsules with prevention from oxidation were developed and optimized using response surface methodology. The effects of formulation variables (pH at complex coacervation, gelatin concentration, and core/wall ratio) on multiple response variables (yield, encapsulation efficiency, antioxidation rate, percent of drug released in 1 h, and time to 85% drug release) were systemically investigated. A desirability function that combined these five response variables was constructed. All response variables investigated were found to be highly dependent on the formulation variables, with strong interactions observed between the formulation variables. It was found that optimum overall desirability of AO microcapsules could be obtained at pH 6.20, gelatin concentration 25.00%, and core/wall ratio 40.40%. The experimental values of the response variables highly agreed with the predicted values. The antioxidation rate of optimum formulation was approximately 8 times higher than that of AO. The in-vitro drug release from microcapsules was followed Higuchi model with super case-II transport mechanism.

Involvement of JNK-initiated p53 accumulation and phosphorylation of p53 in pseudolaric acid B induced cell death.

A terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was used to determine that apoptosis causes HeLa cell death induced by pseudolaric acid B. The c-Jun N-terminal kinase (JNK) inhibitor SP600125 decreased p53 protein expression during exposure to pseudolaric acid B. SP600125 decreased the phosphorylation of p53 during pseudolaric acid B exposure, indicating that JNK mediates phosphorylation of p53 during the response to pseudolaric acid B. SP600125 reversed pseudolaric acid B-induced down-regulation of phosphorylated extracellular signal-regulated protein kinase (ERK), and protein kinase C (PKC) was activated by pseudolaric acid B, whereas staurosporine, calphostin C, and H7 partly blocked this effect. These results indicate that p53 is partially regulated by JNK in pseudolaric acid B-induced HeLa cell death and that PKC participates in pseudolaric acid B-induced HeLa cell death.

Clinical study on Ganbi decoction in treating antituberculotic agent-caused liver injury.

OBJECTIVE: To study the effect and mechanism of Ganbi decoction (GBD) in treating patients with antituberculotic agent caused liver injury (ATB-LI). METHODS: One hundred and twenty-eight patients with ATB-LI were randomly assigned to the treated group (n = 66) and the control group (n = 62) with the envelop method. Meanwhile, 60 healthy persons were selected as the healthy control group. The treated group was treated by GBD one dose every day with the constituents modified depending on patients' symptoms, and the control group was treated with glucuronolactone tablets and inosine injection. One week was taken as one treatment course. The changes of clinical syndromes, physical signs, T-lymphycyte sub-groups and serum level of nitric oxide (NO) were observed before and after treatment and the recovery time of liver function was recorded. The outcome was compared with that in the healthy control group. RESULTS: In the treated group, 28 patients (42.4%) were cured, 30 (45.5%) improved and 8 (12.1%) ineffectively cured, the total effective rate being 87.9% (58/66). In the control group, 17 patients (27.4%) were cured, 24 (38.7%) improved, and 21 (33.9%) ineffectively cured, the total effective rate being 66.1% (41/62). The total effective rate in the treated group was significantly higher than that in the control group (P < 0.05). Liver function was improved in both groups, recovery time in the treated group was 12.0 +/- 7.0 days, which was significantly shorter than that in the control group (16.0 +/- 8.0 days), showing significant difference between the two groups (P < 0.05). The levels of CD3, CD4 and CD8 were significantly higher and level of NO significantly lower in the two groups of patients than those in the healthy control group (P < 0.05), but these parameters were improved more significantly in the treated group after treatment, when compared with those before treatment or with those in the control group, all showing significant difference (P < 0.05). CONCLUSION: GBD could prevent ATB-LI, and its mechanism could be by way of reducing NO production induced by endotoxin of macrophage and stimulating the proliferation of T-lymphycyte to elevate immunity.

SP110 and PMP22 polymorphisms are associated with tuberculosis risk in a Chinese-Tibetan population.

Susceptibility to tuberculosis (TB) is partially dependent on host genetic variability. SP110 and PMP22 are candidate genes identified in this study as associated with human susceptibility to TB. Here we performed an association analysis in a case-control study of a Tibetan population (217 cases and 383 controls). Using bioinformatics methods, we identified two SNPs in SP110 that may decrease susceptibility to TB (rs4327230, p<0.001, OR: 0.37, 95%CI: 0.25-0.55; rs2114591, p<0.001, OR: 0.59, 95%CI: 0.45-0.78), whereas one SNP in PMP22 appeared to increase TB risk (rs13422, p=0.003, OR: 1.45, 95%CI: 1.14-1.84). SNPs rs4327230 and rs2114591 remained significant after Bonferroni correction (p<0.00178). We found that the "GC" haplotype in SP110 was protective against TB, with a 64% reduction in disease risk. "CA" and "CG" in PMP22 were also associated with a protective effect. Our study indicates there is an association between specific gene polymorphisms and TB risk in a Tibetan population, and may help to identify those TB-affected individuals most susceptible to disease.

Pseudolaric acid B induces apoptosis through p53 and Bax/Bcl-2 pathways in human melanoma A375-S2 cells.

Pseudolaric acid B is a major compound found in the bark of Pseudolarix kaempferi Gordon. In our study, pseudolaric acid B inhibited growth of human melanoma cells, A375-S2 in a time- and dose-dependent manner. A375-S2 cells treated with pseudolaric acid B showed typical characteristics of apoptosis including morphologic changes, DNA fragmentation, sub-diploid peak in flow cytometry, cleavage of poly-ADP ribose polymerase (PARP) and degradation of inhibitor of caspase-activated DNase (ICAD). P53 protein expression was upregulated while cells were arrested at the G2/M phase of the cell cycle. There was a decrease in the expression of anti-apoptotic Bcl-2 and Bcl-xL proteins, whereas pro-apoptotic Bax was increased. The two classical caspase substrates, PARP and ICAD, were both decreased in a time-dependent manner, indicating the activation of downstream caspases.

[Mechanisms of capsaicin-induced apoptosis of human melanoma A375-S2 cells].

OBJECTIVE: To study the mechanisms of capsaicin-induced apoptosis of human melanoma A375-S2 cells. METHODS: MTT assay, fluorescence microscopy, DNA agarose gel electrophoresis, flow cytometry and Western blot analysis were carried out to assess the morphological and biochemical changes of A375-S2 cells after capsaicin treatment. RESULTS: Capsaicin induced A375-S2 cell death in a time- and dose-dependent manner. Sub-diploid peak was seen at 24 h after 250 micromol/L capsaicin treatment, and apoptotic bodies and DNA ladder were observed at 36 h after capsaicin treatment. The expression of inhibitor of caspase activated DNase (ICAD) was reduced with the lapse of time. CONCLUSION: Capsaicin induces A375-S2 cell apoptosis and down-regulation of ICAD contributes to this process.

[Pseudolaric acid B induces human melanoma A375-S2 cell apoptosis in vitro].

OBJECTIVE: To study the mechanisms of pseudolaric acid B-induced apoptosis on A375-S2 cells. METHOD: MTT, fluorescence microscope observation, DNA agarose gel electrophoresis and Western blot analysis wereused. RESULT: Pseudolaric acid Binduces A375-S2 cell apoptosis in a time and dose-dependent manner. Apoptotic bodies and DNA ladder were observed in 5 micromol x L(-1) pseudolaric acid B-treated A375-S2 cells for 36 h. The expression of Bcl-2, Bcl-xL and ICAD was reduced time dependently, whereas the expression of Bax was increased. CONCLUSION: The major cause of pseudolaric acid B induced cytotoxicity on A375-S2 cells was apoptosis. Mitochondria proteins and ICAD might be involved in the apoptotic pathways of pseudolaric acid B-treated A375-S2 cells.

Preparation, characterization, and antitumor activities of folate-decorated docetaxel-loaded human serum albumin nanoparticles.

CONTEXT: Docetaxel is now a major antitumor drug in clinical use for the treatment of a variety of tumors. The ethanol/Tween 80 solvent required in the formulation to increase the docetaxel solubility is at least partly responsible for the hypersensitivity reaction, decreased uptake by tumor tissue, and increased exposure to other body compartments. OBJECTIVE: The present study was aimed at developing hydrosoluble DTX-FA-HSANPs targeting tumor cells and to investigate antitumor activities of the nanoparticles. MATERIALS AND METHODS: The DTX-HSANPs were prepared using a desolvation technique and the carboxylic groups of NHS-folate were conjugated with the amino groups of the human serum albumin nanoparticles, and studied their size and zeta potential, drug loading efficiency, surface morphology, release properties in vitro, and antitumor activities. RESULTS: The spherical nanoparticles obtained were negatively charged with a zeta potential of about -30 mV and characterized around 150 nm with a narrow size distribution. Drug loading efficiency was approximately 17.2%. The folate-decorated nanoparticles targeted a human hepatoma cell line effectively. The in vitro drug release of DTX-FA-HSANPs in the first 96 h corresponded with the following equation: Q = 18.87851 - 0.13866t + 0.21276t² - 0.00704t³ + 0.0000847854t4 - 0.00000034991t5 (R² = 0.98155). Moreover, the in vitro antitumor activities of DTX-FA-HSANPs were close to the activities of the positive control (docetaxel). The in vivo inhibition ratios of DTX-FA-HSANPs and docetaxel were 66.2% and 59.5%, respectively, at a dose of 5 mg/kg. DISCUSSION AND CONCLUSION: In light of the observed antitumor activities, it would be of considerable interest to collect sufficient data for the clinical application of docetaxel-loaded nanoparticles.

Pseudolaric acid B induces apoptosis via activation of c-Jun N-terminal kinase and caspase-3 in HeLa cells.

Pseudolaric acid B was isolated from Pseudolarix kaempferi Gordon (Pinaceae) and was evaluated for the anti-cancer effect in HeLa cells. We ob-served that pseudolaric acid B inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. HeLa cells treated with pseudolaric acid B showed typical characteristics of apoptosis including the morphological changes and DNA fragmentation. JNK inhibitor, SP600125,markedly inhibited pseudolaric acid B-induced celldeath. In addition, Bcl-2 expression was down-regulated while Bax protein level was up-regulated.Caspase-3 inhibitor, z-DEVD-fmk, partially blocked pseudolaric acid B-induced cell death, and the expression of two classical caspase substrates,PARP and ICAD, were both decreased in a time-dependent manner, indicative of downstream cas-pase activation.

Econazole Nitrate Induces Apoptosis in MCF-7 Cells via Mitochondrial and Caspase Pathways.

Econazole nitrate (EN), a synthetic compound, is now in use as a routine antifungal drug. EN was shown to have antitumor effect, the tumor cell killing mechanisms, however, remain unclear. In this research, the apoptosis-inducing effect of EN on MCF-7 cells was investigated. The results showed that EN inhibited the proliferation of MCF-7 cells in a time- and dose-dependent manner by MTT method and colony forming assay. MCF-7 cells treated with EN showed typical characteristics of apoptosis including the morphological changes and DNA fragmentation. Meanwhile, the loss of mitochondrial membrane potential was showed by flow cytometry. In addition, western blot analysis showed that EN resulted in the decrease expression of procaspase-3, procaspase-9 and bcl-2. In conclusion, these findings suggest that EN may be an effective way for treating human breast cancer. The anti-tumor mechanisms of EN might involve mitochondrial and caspase pathways.