Cisplatin-loaded polymeric nanoparticles: characterization and potential exploitation for the treatment of non-small cell lung carcinoma.

Cisplatin-loaded poly(l-glutamic acid)-g-methoxy poly(ethylene glycol 5K) nanoparticles (CDDP-NPs) were characterized and exploited for the treatment of non-small cell lung carcinoma (NSCLC). In vitro metabolism experiments showed that a glutamic acid 5-mPEG ester [CH3O(CH2CH2O)nGlu] was generated when the poly(l-glutamic acid)-g-methoxy poly(ethylene glycol 5K) (PLG-g-mPEG5K) was incubated with HeLa cells. This suggests that the poly(glutamic acid) backbone of the PLG-g-mPEG5K is biodegradable. Furthermore, the size of the CDDP-NPs in an aqueous solution was affected by varying the pH (5.0-8.0) and their degradation rate was dependent on temperature. The CDDP-NPs could also bind to the model nucleotide 2'-deoxyguanosine 5'-monophosphate, indicating a biological activity similar to cisplatin. The CDDP-NPs showed a significantly lower peak renal platinum concentration after a single systemic administration when compared to free cisplatin. In vivo experiments with a Lewis lung carcinoma (LLC) model showed that the CDDP-NPs suppressed the growth of tumors. In addition, LLC tumor-bearing mice treated with the CDDP-NPs (5mg/kg cisplatin eq.) showed much longer survival rates (median survival time: 51days) as compared with mice treated with free cisplatin (median survival time: 18days), due to the acceptable antitumor efficacy and low systemic toxicity of CDDP-NPs. These results suggest that the CDDP-NPs may be successfully applied to the treatment of NSCLC.

Shi C ，Yu H ，Sun D ，Ma L ，Tang Z ，Xiao Q ，Chen X ... -  《-》

Pharmacokinetics, biodistribution and in vivo efficacy of cisplatin loaded poly(L-glutamic acid)-g-methoxy poly(ethylene glycol) complex nanoparticles for tumor therapy.

Platinum-based polymeric nano-drugs, especially cisplatin-loaded polymeric nanoparticles (CDDP-NPs), have been extensively exploited for the treatment of solid tumors. However, it is still unclear what role the processing procedure and the properties of the polymeric carrier materials may play in influencing the plasma pharmacokinetics, biodistribution and in vivo efficacy of CDDP-NPs. In this study, a series of poly(l-glutamic acid)-g-methoxy poly(ethylene glycol) (PLG-g-mPEG) copolymers were synthesized for the preparation of CDDP-loaded PLG-g-mPEG (CDDP/PLG-g-mPEG) nanoparticles. All of the parameters, including PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length, ultrafiltration purification and cisplatin loading content, were found to have a significant influence on the plasma pharmacokinetics of the CDDP/PLG-g-mPEG nanoparticles. The blood circulation time of the nanoparticles was prolonged with increases in PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length and CDDP loading content. The use of ultrafiltration purification could prolong the blood circulation time of the nanoparticles as well. Experiments to measure the pharmacokinetics and biodistribution demonstrated that the selected CDDP/PLG-g-mPEG nanoparticles, NP10, had a long blood circulation time and could achieve selective and significant accumulation in Lewis lung carcinoma (LLC) tumors. The platinum plasma concentrations in the LLC tumor-bearing mice receiving NP10 remained up to 46-fold higher than that of mice receiving equivalent doses of free CDDP. In addition, the plasma area under the concentration time curve (AUC) of NP10 was 31-fold higher than that of free CDDP in 48h. The platinum concentration ratio of NP10 to free CDDP in tumors reached as high as 9.4. The tumor AUC ratio of NP10 to CDDP was 6. Using a mouse C26 tumor model, here we demonstrate that NP10 improves the safety and tolerance in vivo when compared to CDDP and effectively inhibits the growth of C26 tumors. Furthermore, increasing the dosage of NP10 by 2 or 3-fold of free CCDP improved its anticancer efficacy to comparable or higher levels. These results indicate that CDDP/PLG-g-mPEG nanoparticles have greater potential for the treatment of solid tumors in clinical application.

Yu H ，Tang Z ，Zhang D ，Song W ，Zhang Y ，Yang Y ，Ahmad Z ，Chen X ... -  《-》

Methoxypoly(ethylene glycol)-block-poly(L-glutamic acid)-loaded cisplatin and a combination with iRGD for the treatment of non-small-cell lung cancers.

CDDP is loaded into methoxypoly(ethylene glycol)-block-poly(L-glutamic acid) (mPEG-b-PLG), and a combination with iRGD is applied for NSCLC chemotherapy. The CDDP-loaded micelles show sustained cisplatin release in PBS, dose- and time-dependent inhibition to HeLa and A549 cell proliferation, and no apparent hemolysis activities. In in vivo studies using subcutaneous NSCLC xenograft models (A549), both free CDDP and CDDP-loaded micelles show an evident anti-tumor effect. However, the toxicity of CDDP is significantly reduced in the cases of CDDP-loaded micelles and co-administration with iRGD, and the survival time is prolonged by over 30%. Therefore, mPEG-b-PLG-loaded cisplatin and the combination with iRGD provides a promising new therapy for NSCLC.

Song W ，Li M ，Tang Z ，Li Q ，Yang Y ，Liu H ，Duan T ，Hong H ，Chen X ... -  《-》

Cisplatin Loaded Poly(L-glutamic acid)-g-Methoxy Poly(ethylene glycol) Complex Nanoparticles for Potential Cancer Therapy: Preparation, In Vitro and In Vivo Evaluation.

Yu H ，Tang Z ，Li M ，Song W ，Zhang D ，Zhang Y ，Yang Y ，Sun H ，Deng M ，Chen X ... -  《Journal of Biomedical Nanotechnology》

Synergistic Antitumor Efficacy Mediated by Liposomal Co-Delivery of Polymeric Micelles of Vinorelbine and Cisplatin in Non-Small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC) is an aggressive tumor with high mortality and poor prognosis. In this study, we designed a liposome encapsulating polymeric micelles (PMs) loaded with vinorelbine (NVB) and cis-diamminedichloroplatinum (II) (cisplatin or CDDP) for the treatment of NSCLC. Sodium poly(α-l-glutamic acid)-graft-methoxy-polyethylene glycol (PLG-G-PEG5K) was used to prepare NVB-loaded NVB-PMs and CDDP-loaded CDDP-PMs that were co-encapsulated into liposomes by a reverse evaporation method, yielding NVB and CDDP co-delivery liposomes (CoNP-lips) composed of egg phosphatidyl lipid-80/cholesterol/DPPG/DSPE-mPEG2000 at a molar ratio of 52:32:14:2. The CoNP-lips were characterized in terms of particle size, zeta potential, drug content, encapsulation efficiency, and structural properties. Drug release by the CoNP-lips as well as their stability and cytotoxicity was evaluated in vitro, and their antitumor efficacy was assessed in a mouse xenograft model of Lewis lung carcinoma cell-derived tumors. CoNP-lips had a spherical shape with uniform size distribution; the average particle size was 162.97±9.06 nm, and the average zeta potential was -13.02±0.22 mV. In vitro cytotoxicity analysis and the combination index demonstrated that the CoNP-lips achieved a synergistic cytotoxic effect at an NVB:CDDP weight ratio of 2:1 in an NSCLC cell line. There was sustained release of both drugs from CoNP-lips. The pharmacokinetic analysis showed that CoNP-lips had a higher plasma half-life than NP solution, with 6.52- and 8.03-fold larger areas under the receiver operating characteristic curves of NVB and CDDP. CoNP-lips showed antitumor efficacy in tumor-bearing C57BL/6 mice and drug accumulation in tumors via the enhanced permeability and retention effect. CoNP-lips are a promising formulation for targeted therapy in NSCLC.

Wang S ，Gou J ，Wang Y ，Tan X ，Zhao L ，Jin X ，Tang X ... -  《International Journal of Nanomedicine》