Development of targeted sunitinib plus vinorelbine liposomes modified with DSPE-PEG_(2000)-pemetrexed conjugate and the inhibitory effect toresistant breast cancer in vitro

Multidrug resistance （MDR） of breast cancer is a major cause of failure in chemotherapy. In the present study, a distearoylphosphatidyl ethanolamine-polyethylene glycol-pemetrexed （DSPE-PEG2000-PMT） conjugate was synthesized from DSPE-PEG2000-NH2 and pemetrexed, and targeted sunitinib plus vinorelbine liposomes were developed by modifying DSPE-PEG20o0-PMT onto the surface of liposomes to overcome the MDR of breast cancer. The synthesized DSPE-PEG2000-PMT was confirmed to be consistent with the target product by matrix-assisted laser desorption/ionization time of flight mass spectrometry （MALDI-TOF-MS）. The concentrations of sunitinib and vinorelbine were measured simultaneously by high performance liquid chromatography （HPLC）. The analysis was performed on an ODS column at 30℃ at a wavelength of 215 nm with the mobile phase consisting of acetonitrile, 0.05 M KH2PO4 （pH 3.5） and triethylamine （35：65：0.3, v/v/v）. The limits of detection for sunitinib and vinorelbine were 25 ng/mL and 5 ng/mL, respectively, and the limits of quantification for both drugs were 0.25μg/mL. Two drugs were linearly correlated in the range of 0.5-25.0 μg/mL. For varying types of liposomes, the encapsulation efficiencies were 〉90%; the particle sizes were approximately 90 nm, and zeta potentials were slightly negative. The inhibitory effects were evaluated in the resistant breast cancer MCF-7/Adr cells. The results revealed that targeted sunitinib plus vinorelbine liposomes exhibited the strongest inhibitory effect to the resistant MCF-7/Adr cells among the varying formulations. Targeted coumarin liposomes were used as a fluorescent probe to evaluate the targeting effect to resistant breast cancer MCF-7/Adr cells. The results demonstrated that the targeted coumarin liposomes displayed the highest cellular uptake compared to non-targeted formulations. In conclusion, the targeted sunitinib plus vinorelbine liposomes represented a novel type of nano-formulations, which could accumulate in the resistant breast cancer cells, thereby inhibiting proliferation of the resistant cancer cells. Accordingly, the targeted sunitinib plus vinorelbine liposomes may provide a new strategy for circumventing the drug resistance in the resistant breast cancer.

An ATF24 peptide-functionalized β-elemene-nanostructured lipid carrier combined with cisplatin for bladder cancer treatment

Objective:In this study,we aimed to develop an amino-terminal fragment(ATF)peptide-targeted liposome carryingβ-elemene(ATF24-PEG-Lipo-β-E)for targeted delivery into urokinase plasminogen activator receptor-overexpressing bladder cancer cells combined with cisplatin(DDP)for bladder cancer treatment.Methods:The liposomes were prepared by ethanol injection and high-pressure microjet homogenization.The liposomes were characterized,and the drug content,entrapment efficiency,andin vitro release were studied.The targeting efficiency was investigated using confocal microscopy,ultra-fast liquid chromatography,and an orthotopic bladder cancer model.The effects of ATF24-PEG-Lipo-β-E combined with DDP on cell viability and proliferation were evaluated by a Cell Counting Kit-8(CCK-8)assay,a colony formation assay,and cell apoptosis and cell cycle analyses.The anticancer effects were evaluated in a KU-19-19 bladder cancer xenograft model.Results:ATF24-PEG-Lipo-β-E had small and uniform sizes(~79 nm),high drug loading capacity(~5.24 mg/mL),high entrapment efficiency(98.37±0.95%),and exhibited sustained drug release behavior.ATF24-PEG-Lipo-β-E had better targeting efficiency and higher cytotoxicity than polyethylene glycol(PEG)ylatedβ-elemene liposomes(PEG-Lipo-β-E).DDP,combined with ATF24-PEG-Lipo-β-E,exerted a synergistic effect on cellular apoptosis and cell arrest at the G2/M phase,and these effects were dependent on the caspase-dependent pathway and Cdc25C/Cdc2/cyclin B1 pathways.Furthermore,thein vivo antitumor activity showed that the targeted liposomes effectively inhibited the growth of tumors,using the combined strategy.Conclusions:The present study provided an effective strategy for the targeted delivery ofβ-elemene(β-E)to bladder cancer,and a combined strategy for bladder cancer treatment.

Non-viral liposome-mediated transfer of brain-derived neurotrophic factor across the blood-brain barrier

Brain-derived neurotrophic factor（BDNF） plays an important role in the repair of central nervous system injury,but cannot directly traverse the blood-brain barrier.Liposomes are a new type of non-viral vector,able to carry macromolecules across the blood-brain barrier and into the brain.Here,we investigate whether BDNF could be transported across the blood-brain barrier by tail-vein injection of liposomes conjugated to transferrin（Tf） and polyethylene glycol（PEG）,and carrying BDNF modified with cytomegalovirus promoter（pC MV） or glial fibrillary acidic protein promoter（p GFAP）（Tf-p CMV-BDNF-PEG and Tf-p GFAP-BDNF-PEG,respectively）.Both liposomes were able to traverse the blood-brain barrier,and BDNF was mainly expressed in the cerebral cortex.BDNF expression in the cerebral cortex was higher in the Tf-p GFAP-BDNF-PEG group than in the Tf-p CMV-BDNF-PEG group.This study demonstrates the successful construction of a non-virus targeted liposome,Tf-p GFAP-BDNF-PEG,which crosses the blood-brain barrier and is distributed in the cerebral cortex.Our work provides an experimental basis for BDNF-related targeted drug delivery in the brain.

Synthesis Hexadecyl 3-{4-[2-Hydroxy-3(isopropylamino)propoxy] phenyl}propionate as Potential Ligand for Liposome Targeting to Ischemic Myocardium

Novel hexadecyl 3-{4-[2-hydroxy-3(isopropylamino)propoxy]phenyl}propionate(HPP)was synthesized and its effect on delivery of liposomes into cultured cardiomyocytes was examined.The structure of HPP was characterized by IH NMR,1R and MS.The amount of cardiomyocytes uptake of HPP-liposome was 3.9-fold higher than plain-liposome,and the increase was 6.2-fold when hypoxia happens.It indicated that HPP was a potential ligand for liposome targeting to ischemic myocardium.