和厚朴酚纳米混悬剂的制备及其体内外研究

Honokiol nanosuspensions: preparation, in vitro and in vivo evaluation

和厚朴酚(honokiol,HK)具有多种药理学活性,但难溶于水,稳定性差,限制了其临床应用。本研究拟制备其纳米混悬剂以解决上述问题。采用反溶剂沉淀法,使用聚乙烯吡咯烷酮(PVP)、牛血清白蛋白(BSA)为复合稳定剂,制备HK纳米混悬剂;用动态光散射测定其粒径大小,透射电镜观察其形态,在室温及不同介质中放置观察HK纳米混悬剂稳定性;体外透析测定其释放情况;MTT法检测HK纳米混悬剂对4T1乳腺癌细胞的生长抑制;在4T1荷瘤小鼠模型上考察其体内的抗肿瘤效果。结果表明,制备的HK纳米混悬剂为类球形,载药量为48.62%,稳定性较好,平均粒径为(83.40±1.042)nm,多分散系数为0.223±0.011,zeta电位为(-42.2±1.2)m V;体外缓慢释放药物;HK纳米混悬剂对4T1细胞毒性明显高于溶液组(IC_(50),8.36μg·m L^(-1)和37.58μg·m L^(-1),P<0.05)。在体内,HK纳米混悬剂对肿瘤的抑制具有良好的剂量依赖性;中、高剂量的HK纳米混悬剂(40和60 mg·kg^(-1),2天1次)对肿瘤抑瘤率分别为55.67%和67.28%,显著高于紫杉醇注射液(47.9%)。而高剂量HK原料药(60 mg·kg^(-1))每天口服给药,肿瘤抑瘤率只有54.13%。综上,本研究制备的HK纳米混悬剂粒径小、载药量高、稳定性较好,解决了难溶和难给药问题,显著提高了体内外抗肿瘤作用,有望成为一种有前景的抗肿瘤制剂。

Honokiol（HK）have extensive pharmacological activities,but its poor solubility and instability restricted its clinical application and efficacy exertion.HK nanosuspensions（HK-NSps）were designed in this study in order to solve the problems.HK-NSps were prepared by antisolvent precipitation method,using polyvinylpyrrolidone（PVP）and bovine serum albumin（BSA）as a combined stabilizer.The particle size was measured using dynamic light scattering method,the morphology was observed by transmission electron microscopy.The size change and drug content of HK-NSps in various physiological media during the storage at ambient temperature was examined to evaluate their storage stability.Dialysis method was used to study their drug release in vitro.MTT assay was used to assess their in vitro cytotoxicity against 4T1 breast cancer cell line.Anti-tumor effect in vivo was also investigated in 4T1 tumor-bearing mice.HK-NSps were prepared with high drug loading content of 48.62%,nearly spherical shape and good storage stability.The average particle size was（83.40±1.042）nm,the polydispersity index（PDI）value was 0.223±0.011,the zeta potential was（-42.2±1.2）m V.HK-NSps showed sustained in vitro drug release and enhanced cytotoxicity in contrast to free HK against 4T1 cells（IC50,8.36μg·mL^-1 vs 37.58μg·mL^-1,P〈0.05）.The in vivo study on 4T1 tumor-bearing mice demonstrated that HK-NSps showed good dose-dependent tumor inhibition rate（TIR）.In contrast to4 mg·kg^-1 of PTX injection（TIR,47.9%）,medium and high dose of HK-NSps displayed improved therapeutic efficacy（TIR,55.67%for 40 mg·kg^-1,67.28%for 60 mg·kg^-1,P〈0.05）.In contrast,the high dose of HK crude drug（60 mg·kg^-1）had TIR of only 54.13%even administrated every day.In conclusion,HK-NSps were prepared with small size,high drug-loading capacity,and good stability.The improved in vitro and in vivo antitumor efficacy demonstrated that HK can be a promising antitumor drug in combination with nanosuspensions technology.