Construction and Swelling Properties of Thermosensitive N-isopropyl Acrylamide Microspheres With Controllable Size.

In recent years, thermosensitive poly(N-isopropylacrylamide) (PNIPAM) microspheres have received extensive attention due to their many advantages, and their size and swelling ratio are two crucial factors. In this paper, homogeneous and hollow thermosensitive microspheres were prepared by free radical polymerization in an aqueous solution. The effects of the process parameters on the size of the microspheres were studied. The results indicated that the change in size during reaction at different temperatures was not obvious. The size of the microspheres ranged from 802 ± 35.4 nm to 423 ± 33.7 nm with the changes in the dosage of the initiator. Meanwhile, it was observed that the size of microspheres was slightly reduced due to the increase of reaction time. When the dosage of methyl methacrylate (MAA) is increased, the size of the hollow microspheres increased by more than 110%. The average size of the microspheres was smaller when the content of sodium dodecyl sulfate (SDS) was 3 wt%. The microspheres with varying reaction parameters showed a continuous decreasing swelling ratio when the temperatures were changed from 28 °C to 35 °C. In comparison with homogeneous microspheres, the average swelling ratio of hollow microspheres was larger.

[Expression of tissue factor induced by IL-6 in HUVEC].

OBJECTIVE: To investigate the effects of IL-6 at the expression of tissue factor (TF) in human vein endothelial cells(HUVECs). METHODS: HUVECs were incubated with IL-6 at the concentration of 0.5 ng/mL. Cell viability was measured by CCK-8 assay. The TF mRNA was detected by reverse transcript-polymerase chain reaction(RT-PCR) method. RESULTS: When HUVECs were exposed to IL-6 (0.5 ng/mL) within a period of 72 h, their viability did not decrease in comparison with the control; there was no statistical difference between the two groups. After the HUVECs were exposed to IL-6 (0.5 ng/mL) for 6 h, the TF mRNA level increased, and it reached the peak at 12 h; then it began to decline. The expression of TF mRNA induced by IL-6 was evidently detected from 6 h to 48 h. After the HUVECs were treated by IL-6 over 72 h, the expression of TF mRNA was no longer detected in HUVECs. CONCLUSION: IL-6 at the concentration of 0.5 ng/mL did not exert direct effect on cell viability. The increase of TF mRNA expression in HUVECs induced by IL-6 could play an important role in the modulation of blood coagulation disorder and in the mechanism related to coagulation system changes during

[Effects of curcumin on TNF-alpha and TGF-beta1 in serum and lung tissue of SiO2-induced fibrosis in mice].

AIM: To study the effects of curcumin on TNF-alpha and TGF-beta1 in serum and lung tissue of SiO2-induced fibrosis in mice. METHODS: 75 mice were divided into five groups. After treated with curcumin 6 and 9 mice of each group were sacrificed on day 14 and 42 respectively to take their blood and lung tissue. The level of TNF-alpha and TGF-beta1 was observed by ELISA. RESULTS: The infection reaction of lung tissue and fibrosis in model group was obvious. Compared with sham operation group, TNF-alpha and TGF-beta1 in serum and lung tissue increased significantly(P<0.01), but decreased in different degrees after treated with curcumin(P<0.05). CONCLUSION: Curcumin can decrease the level of TNF-alpha and TGF-beta1 in serum and lung tissue of SiO2-induced fibrosis in mice and have the anti-fibrosis role by deregulating cytokine level.