[Preparation of paclitaxel-loaded and folic acid-modified poly (lactic-co-glycolic acid) nano-micelles and in vitro anticancer effect on cervical cancer HeLa cells].

The paclitaxel-loaded and folic acid-modified poly(lactic-co-glycolic acid) nano-micelles(PTX@FA-PLGA-NMs) were prepared by the emulsion solvent evaporation method, and the parameters of paclitaxel-loaded nano-micelles were optimized with the particle size and PDI as evaluation indexes. The morphology of the nano-micelles was observed by transmission electron microscopy(TEM), and the stability, drug loading and encapsulation efficiency were systematically investigated. In vitro experiments were performed to study the cytotoxic effects of nano-micelles, apoptosis, and cellular uptake. Under the optimal parameters, the nano-micelles showed the particle size of(125.3±1.2) nm, the PDI of 0.086±0.026, the zeta potential of(-20.0±3.8) mV, the drug loading of 7.2%±0.75%, and the encapsulation efficiency of 50.7%±1.0%. The nano-micelles were in regular spherical shape as observed by TEM. The blank FA-PLGA-NMs exhibited almost no inhibitory effect on the proliferation and growth of tumor cells, while the drug-loaded nano-micelles and free PTX exhibited significant inhibitory effects. The IC_(50) of PTX@FA-PLGA-NMs and PTX was 0.56 µg·mL~(-1) and 0.66 µg·mL~(-1), respectively. The paclitaxel-loaded nano-micelles were potent in inhibiting cell migration as assessed by the scratch assay. PTX@FA-PLGA-NMs had good pro-apoptotic effect on cervical cancer HeLa cells and significantly promoted the uptake of HeLa cells. The results of in vitro experiments suggested that PTX@FA-PLGA-NMs could target and treat cervical cancer HeLa cells. Therefore, as nanodrug carriers, PTX@FA-PLGA-NMs with anti-cancer activity are a promising nano-system for improving the-rapeutic effects on tumors.

Inhibition of Shear-Induced Platelet Aggregation by Xueshuantong via Targeting Piezo1 Channel-Mediated Ca2+ Signaling Pathway.

XueShuanTong (XST) comprising therapeutically active ginsenosides, a lyophilized extract of Panax notoginseng roots, is extensively used in traditional Chinese medicine to treat ischemic heart and cerebrovascular diseases. Our recent study shows that treatment with XST inhibits shear-induced thrombosis formation but the underlying mechanism remained unclear. This study aimed to investigate the hypothesis that XST inhibited shear-induced platelet aggregation via targeting the mechanosensitive Ca2+-permeable Piezo1 channel by performing platelet aggregation assay, Ca2+ imaging and Western blotting analysis. Exposure to shear at physiologically (1,000-2000 s-1) and pathologically related rates (4,000-6,000 s-1) induced platelet aggregation that was inhibited by treatment with GsMTx-4. Exposure to shear evoked robust Ca2+ responses in platelets that were inhibited by treatment with GsMTx-4 and conversely enhanced by treatment with Yoda1. Treatment with XST at a clinically relevant concentration (0.15 g L-1) potently inhibited shear-induced Ca2+ responses and platelet aggregation, without altering vWF-mediated platelet adhesion and rolling. Exposure to shear, while resulting in no effect on the calpain-2 expression in platelets, induced calpain-2-mediated cleavage of talin1 protein, which is known to be critical for platelet activation. Shear-induced activation of calpain-2 and cleavage of talin1 were attenuated by treatment with XST. Taken together, our results suggest that XST inhibits shear-induced platelet aggregation via targeting the Piezo1 channel to prevent Piezo1-mediated Ca2+ signaling and downstream calpain-2 and talin1 signal pathway, thus providing novel insights into the mechanism of the therapeutic action of XST on platelet aggregation and thrombosis formation.

Preparation of RGD Peptide/Folate Acid Double-Targeted Mesoporous Silica Nanoparticles and Its Application in Human Breast Cancer MCF-7 Cells.

PHARMACOLOGICAL RELEVANCE: Paclitaxel (PTX) is currently the only botanical drug that can control the growth of cancer cells. Paclitaxel is widely used in the treatment of breast cancer, ovarian cancer, uterine cancer, non-small cell lung cancer and other cancers. AIM: Folate receptor and integrin α v ß 3 are highly expressed on the surface of human breast cancer cells MCF-7. Folic acid and arginine-glycine-aspartate (Arg-Gly-Asp, RGD) tripeptide sequence have a high affinity for folate receptor and integrin α v ß 3, respectively. To enhance the effect on breast cancer, we constructed the folate acid and RGD peptide dual-targeted (MSNs-NH2-FA-RGD) drug-carrier based on mesoporous silica nanoparticles. METHODS: The structure of mesoporous nanocarriers was characterized by Fourier transform infrared spectroscopy, nitrogen adsorption-desorption analysis, transmission electron microscopy, laser particle size analyzer, and thermogravimetric analysis. Paclitaxel was chosen as the model drug. The targeting-ability was verified by observing the uptake of mesoporous carriers loaded with rhodamine in MCF-7, MCF-10A, and HeLa cells using a fluorescence microscope. The cytotoxicity of the blank carrier MSNs-NH2-FA-RGD and the efficacy of the drug carrier PTX@MSNs-NH2-FA-RGD were assessed by cell experiments. RESULTS: The characterization showed successful construction of a dual-targeted mesoporous silica nanocarrier. Obvious differences were detected in the fluorescence intensity of the three cell lines. The results of the pharmacological tests indicated that the blank nanoparticles do not cause any apparent toxicity on these cells. The IC50 of free PTX and PTX@MSNs-NH2-FA-RGD on MCF-7 cells line treated for 48 h were 35.25±2.57 ng·ml-1 and 22.21±3.4 ng·ml-1 respectively, which indicated that the inhibitory efficacy of PTX@MSNs-NH2-FA-RGD on MCF-7 was 1.6 times than that of free PTX. CONCLUSIONS: The dual-targeted nanocarrier MSNs-NH2-FA-RGD could target breast cancer cells, and sever as a potential candidate in future of drug development.

[Effects of Xueshuantong Injection on thrombosis formation and blood flow in rats].

The aim of this paper was to explore the effect of Xueshuantong Injection(freeze-dried powder,XST) on κ-carrageenan-induced thrombosis and blood flow from the aspects of interactions among blood flow,vascular endothelium and platelets. Fifty male Sprague-Dawley rats(190-200 g) were randomized into five groups: control group, model group, heparin sodium(1 000 U·kg~(-1)) group, low-dose and high-dose(50, 150 mg·kg~(-1)) XST groups. Rats were intraperitoneally injected with corresponding drugs and normal saline(normal control and model groups) for 10 days. One hour after drugs were administered intraperitoneally on the 7 th day, each rat was injected with κ-carrageenan(Type Ⅰ, 1 mg·kg~(-1)) which was dissolved in physiological saline by intravenous administration in the tail to establish tail thrombus model. The lengths of black tails of the rats were measured at 2, 6, 24 and 48 h after modeling. Vevo®2100 small animal ultrasound imaging system was used to detect the internal diameter of rat common carotid artery, blood flow velocity and heart rate, and then the blood flow and shear rate were calculated. Meanwhile, the microcirculatory blood flow perfusion in the thigh surface and tail of rats were detected by laser speckle blood flow imaging system. Platelet aggregometry was used to detect the max platelet aggregation rate in rats. Pathological changes in tail were observed through hematoxylin-eosin staining, and Western blot was used to detect the protein content of platelet piezo1. According to the results, XST could inhibit the rat tail arterial thrombosis and significantly reduce the length of black tail(P<0.05). The blood flow of common carotid artery in XST low dose group was significantly higher than that in the model group(P<0.05). XST high dose group could significantly increase the microcirculatory blood flow perfusion of the tail in rats as compared with the model group(P<0.05). XST high dose group could significantly inhibit platelet aggregation rate(P<0.05) and XST low dose group could significantly inhibit platelet piezo1 protein expression(P<0.01). In summary, XST could play an effect in fighting against thrombosis induced by κ-carrageenan in rats, which may be related to significantly inhibiting platelet aggregation, improving body's blood flow state, maintaining normal hemodynamic environment and affecting mechanical ion channel protein piezo1.

Clinical nurses' attitudes towards death and caring for dying patients in China.

OBJECTIVE: To examine Chinese clinical nurses' attitudes towards death and caring for dying patients, and to examine the relationships between clinical nurses' attitudes towards death and caring for dying patients. METHODS: A convenience sample of 770 clinical nurses from 15 hospitals in China. All participants completed the Chinese version of the Frommelt Attitude Toward Care of the Dying Scale, Form B (FATCOD-B-C), the Chinese version of the Death Attitude Profile-Revised (DAP-R-C), and a demographic questionnaire. RESULTS: The mean score of the FATCOD-B-C items was 95.62 (SD = 7.45). The majority of Chinese clinical nurses were likely to provide care for the dying person's family (mean = 3.77), but did not have a positive attitude towards communication with the dying person(mean = 2.62). The majority of Chinese clinical nurses showed low scores on death avoidance (mean=1.96) and natural acceptance (mean = 1.61), and most of them viewed death as a passageway to a happy afterlife (mean = 4.33). Attitudes towards caring for dying patients were significantly negatively correlated with fear of death (r = -0.120) and positively correlated with approach acceptance (r = 0.127) and natural acceptance (r = 0.117). Factors that predicted clinical nurses' attitudes towards the care of dying patients included education level, fear of death, approach acceptance, religious beliefs, previous education on death and dying, natural acceptance, professional title, and experience with death or dying patients, which accounted for 18.7% of the variance. CONCLUSION: Nurses' personal attitudes towards death were associated with their attitudes towards the care of dying patients. Training and educational programmes for clinical nurses should take into consideration nurses' personal attitudes towards death as well as their cultural backgrounds and religious beliefs.