新型多肽聚酰胺-胺型靶向药物载体的载药性能及细胞吸收和毒性

背景:前期研究通过噬菌体展示体内筛选方法获得了一条NCI-H460非小细胞肺癌特异结合的多肽(Lung cancer targetingpe ptide,LCTP),将该多肽与修饰的聚酰胺-胺型(Polyamidoamine,PAMAM)树枝状高分子材料连接制备了纳米靶向药物载体PAMAM-Ac-FITC-LCTP,该载体在体内外对非小细胞肺癌NCI-H460具有很好的靶向性。目的:在前期研究基础上,进一步研究PAMAM-Ac-FITC-LCTP靶向载体对阿霉素的包埋、释放及其细胞吸收和毒性性能。方法:以筛选到的多肽LCTP为靶向剂,构建了PAMAM-Ac-FITC-LCTP靶向载体。采用物理包埋法将PAMAM-Ac-FITC-LCTP与阿霉素连接,通过体外透析实验观察载体对药物的缓释功能,共聚焦显微镜观察细胞对药物的吸收。以游离阿霉素作为对照,MTT法观察载体载药后对NCI-H460细胞的作用。结果与结论:PAMAM-Ac-FITC-LCTP对阿霉素的最大包埋率为7.46%。载体对药物具有明显的缓释作用,离子浓度、pH和温度对药物的释放具有影响,说明PAMAM-Ac-FITC-LCTP主要是通过静电相互作用与阿霉素结合。PAMAM-Ac-FITC-LCTP/阿霉素短时间内较单独药物更高效进入NCI-H460细胞,而复合物24h的细胞毒性与阿霉素对细胞的毒性基本一致。以上结果说明PAMAM-Ac-FITC-LCTP可能是一个肿瘤治疗和诊断中很有用的药物靶向传输载体。

Drug loading properties, cell uptake and cytotoxicity of new peptide polyamidoamine targeting drug carrier

BACKGROUND:Previous study screened a peptide(lung cancer targeting peptide,LCTP) which could bind NCI-H460 non-small cell lung cancer(NSCLC) by phage display in vivo.LCTP was combined with modified polyamidoamine(PAMAM) dendritic polymers to prepare nano-targeting drug carrier,PAMAM-Ac-FITC-LCTP.It had good targeting capability to NSCLC in vitro and in vivo.OBJECTIVE:To further study the PAMAM-Ac-FITC-LCTP as a targeting carrier on encapsulation,release,cell uptake,and toxicity properties of doxorubicin(DOX) based on previous research.METHODS:Taking screened peptide LCTP as targeting agent,PAMAM-Ac-FITC-LCTP targeting carrier was constructed.PAMAM-Ac-FITC-LCTP was combined with DOX using physical encapsulation method.The carrier on release function of drug was observed by dialysis experiment in vitro.Confocal microscopy was used to observe cells uptake of the PAMAM-Ac-FITC-LCTP/DOX.Free DOX as controls,the effect of carrier on NCI-H460 cells was observed with MTT assay after the drug carrier.RESULTS AND CONCLUSION:The maximum encapsulation rate of PAMAM-Ac-FITC-LCTP to DOX was 7.46%.The carrier had obvious sustained release effect on DOX,and ion concentration,pH and temperature could affect DOX release.It is indicated that PAMAM-Ac-FITC-LCTP could combined with DOX by electrostatic interaction.PAMAM-Ac-FITC-LCTP/DOX was more efficient than individual drugs into NCI-H460 cells in a short period of time;however,the 24-hour cytotoxicity of complex was similar with DOX.These results suggest that PAMAM-Ac-FITC-LCTP might be a useful drug carrier for cancer treatment and clinical diagnosis.