ABSTRACT
Objective: Sialic acid (SA)-modified chlorogenic acid (CA) liposomes (CA-SAL) was prepared by response surface design to investigate its in vitro cytotoxicity and uptake. Methods: CA-SAL was prepared by a modified reverse-phase ethanol injection method. Sephadex G50 column was used to separate the CA-loaded liposomes and the free CA. The drug concentration was determined by HPLC method and the encapsulation efficiency was calculated. With encapsulation efficiency and drug loading as indicators, Box-Behnken response surface design experiments were used to optimize the prescription process of CA-SAL. The MTT method was used to evaluate the cytotoxicity of CA-SAL on human lung cancer cells A549. Inverted fluorescence microscope was used to investigate the uptake of CA-SAL by A549 cells. Results: The optimized preparation conditions: hydrogenated soybean lecithin-CA ratio at 15:1, hydration temperature 60 ℃, ultrasonic power 400 W. The average particle size of CA-SAL was (90.13 ± 0.51) nm, the polydispersity index (PDI) was 0.16 ± 0.01, the zeta potential was (-25.3 ± 0.5) mV, the encapsulation efficiency was 57.8%, RSD was 0.1%. MTT results showed that the inhibitory effect of CA-SAL on A549 cells was significantly greater than CA-CL. Greater cellular uptake of CA-SAL was observed compared with CA-CL. Conclusion: CA-SAL prepared by response surface optimization has a uniform particle size and good stability. SA-modified CA-loaded liposomes could enhance cellular uptake and cytotoxicity of human lung cancer cell A549 in vitro.
ABSTRACT
We used MTT assay to test the cellular cytotoxicity ( NK, LAK, CTL, Macrophage), cytokine activities ( 1L-1, 1L-2, 1L-6, TNF), proliferation of lymphocytes and chemosensitivity of tumor cells, and compared it with radioactive isotope assay. The results showed that the MTT assay may be used to test the cellular cytotoxicity, cytokine ac-tivity, proliferation of lymphocytes and chemosensitivity of tumor cells. We think it is a simple, rapid, economic and safety method.
ABSTRACT
Antisera raised in albino rats against microfilariae of Litomosoides carinii, Brugia pahangi, Brugia malayi and sera from Bancroftian elephantiasis patients promoted rat neutrophil-mediated adherence and cytotoxicity to the microfilariae. Pre-treatment of the immune sera, with microfilarial antigen at a final concentration of 5 and 25 μg per ml blocked cellular adherence and cytotoxicity to the microfilariae indicating the presence of crossreactive antibodies. The heterologous immune sera were effective in eliminating the circulating Litomosoides carinii microfilariae in Mastomys natalensis.