Combination Vinorelbine Liposomesand Methylene Blue Overcomes Tumor Drug Resistance Of Nasopharyngealcarcinoma In Vitro

Objective Selected vinorelbine as model drug,to prepareliposomes,and formulation optimization studies.methylene blue and VLB-Lphysical mixed, to investigate the cytotoxicity of the model drugs onnasopharyngeal carcinoma multidrug resistant cells.Methods PH-gradient method was used to prepare VLB-L.Todetermine drug loading in liposomes by UV. Entrapment efficiency wereapplied to determine the stability of liposomes at4,25℃for30days.MTTassay was applied to investigate the cytotoxicity of PDT and VLB-L onResistant nasopharyngeal carcinoma cells KBV200cells exposed at590nm wavelength light exposure.Results The optimum formula was as follows:the ratio of drugto lipid was1:10,phosphatide:cholesterol was4:1,pH of PBS was7.4,incubation tempreture was50℃,incubation time was15min.Theaverage entrapment efficiency for VLB was92.26%under the optimalformulation. Liposomes were characterized for morphology and size using dynamic light scattering,The particle distribution of size was uniform,theaverage diameter was169.2nm,zeta potential was-9.28mV.The MTT testshowed that VLB-L＋MB inhibit tumor cell growth effect andtime-dependent manner.The inhibition rate of VLB-L＋MB on KBV200cells was much higher after590nm wavelength laser irradiation.Conclusions The methods of the entrapments rate of VLB-Lusing UV detection and separating the liposomes using exclusionchromatography with Sephadex-50were accurate,fast and convenient.Thestability result showed that liposomes stored in4℃would keep stabler.Thedrug releasing experiment in vitro indicated that the lipsomes exhibitedbetter sustained-release efficacy than free drug.Cytology investigationshowed that VLB-L＋MB with strongest anti-drug-resistantnasopharyngeal carcinoma cell growth After590nm laserirradiation,inhibition rate was85.48%.