Studies On The Construction And Application Of Polypeptide-based Anti-tumoral Targeting Formulations

Purpose To enhance antitumoral efficacy of conventional chemotherapeutics, a novel drug-peptide conjuate, docetaxel-Hsp90 inhibitory peptide (P7) active targeting conjugate was prepared and anti-tumoral efficacy was evaluated for non-small cell lung cancer in vivo.Methods A novel docetaxel-peptide (P7) conjugate (DTX-P7) was prepared by so lid-phase peptide synthetic method, then the characteristics of conjugates were investigated by High Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS). To establish a lung cancer xenograft model, human non-small cell lung cancer A549 cells were collected and subcutaneously implanted into the armpit of right forelimb of BALB/c nude mice with a concentration of 8×105/100 μl The tumor formation was continually monitored. When the tumor volume reached 100 mm3,30 nude mice were randomly divided into three groups:Control group, docetaxel (DTX) group and DTX-P7 group. The lung cancer bearing mice were intraperitoneally administered with normal saline, DTX, DTX-P7 (DTX concentration of 10 mg/kg), respectively, once a week for four weeks.The weights of nude mice were recorded, and the maximal and minimal diameters of tumors were measured to calculate tumor volumes and relative tumor volumes. In the 5th week, the mice were sacrificed and tumor tissues were separated from the armpit of right forelimb of nude mice and weighed. Part of tumor tissues were soaked in 4% paraformaldehyde for paraffin stions and HE staining. Then protein was extracted from remaining tumor tissues for western blot test to verify HSP90 expression and the impact on autophagy related proteins of DTX-P7.Results DTX-P7 was successfully prepared and confirmed by specific chromatography conditions. In vivo animal experiments, tumor was successfully induced in all 30 nude mice. During the four weeks of drug administration, there was no significant difference with regard to the body weight among the three groups. Meanwhile, no significant pathological changes was found in heart, liver, spleen, lung, kidney, brain organs which reflected the safety of DTX and DTX-P7. Compared with Control and DTX group, relative tumor volumes and tumor weights of DTX-P7 nude mice significantly reduced, indicating that DTX-P7 exered exellent anti-non-small cell lung cancer effect. HE staining showed that DTX and DTX-P7 treatment induced serious necrosis suggesting that DTX-P7 exerted a significantly cytotoxic and anti-tumor effect in vivo.Conclusion The docetaxel-peptide (P7) conjugates exhibited significant therapeutic effect on non-small cell lung cancer in vivo.Purpose A novel nanodrug, paclitaxel PLGA targeting nanoparticles modified by targeting and cell penetrating peptides for giloma therapy and the anti-tumoral efficacy of the nanoparticles were investigated in vitro.Methods The targeting peptide was specifically screened in human glioma U251 cells by phage display technology and the targeting property was verified by immunohistochemical method. Paclitaxel PLGA nanoparticels were prepared by the interfacial precipitation method (nanoprecipitation). Subsequently, the nanoparticles were modified with the targeting peptide and the cell penetrating peptide TAT by amide condensation reaction to prepare a novel paclitaxel targeted nanodrug(TN-PTX). Characteristics of TN-PTX, including particle size, Zeta potential, drug loading and morphological appearance were investigated. The anti-tumoral efficacy of TN-PTX was also evaluated in vitro by Cell Counting Kit.Results The targeting peptide exhibited a good specificity to glioma. The average particle size of paclitaxel PLGA targeted nanoparticels(TN-PTX) was 350.5±31.8 nm, and the average Zeta potential was -31.9±5.0 mV, and drug loading was 5.01%. The morphology of TN-PTX is basically homogeneous sphere. In vitro inhibition study results indicated that the targeted nanodrug exhibited more efficient inhibitory effects on the U251 cells than conventional drugs with the same concentration of paclitaxel.Conclusion The paclitaxel PLGA targeted nanoparticels modified by cell penetrating peptide exhibited the stable properties and high inhibitory effects on tumor proliferation than conventional drugs in vitro.