Lipid-Polymer Nanoparticles for Folate-Receptor Targeting Delivery of Doxorubicin.

A biocompatible PLGA-lipid hybrid nanoparticles (NPs) was developed for targeted delivery of anticancer drugs with doxorubicin (DOX). The hydrodynamic diameter and zeta potential of DOX-loaded PLGA-lipid NPs (DNPs) were affected by the mass ratio of Lipid/PLGA or DSPE-PEG-COOH/Lecithin. At the 1:20 drug/polymer mass ratio, the mean hydrodynamic diameter of DNPs was the lowest (99.2 1.83 nm) and the NPs presented the encapsulation efficiency of DOX with 42.69 1.30%. Due to the folate-receptor mediated endocytosis, the PLGA-lipid NPs with folic acid (FA) targeting ligand showed significant higher uptake by folate-receptor-positive MCF-7 cells as compared to PLGA-lipid NPs without folate. Confocal microscopic observation and flow cytometry analysis also supported the enhanced cellular uptake of the FA-targeted NPs. The results indicated that the FA-targeted DNPs exhibited higher cytotoxicity in MCF-7 cells compared with non-targeted NPs. The lipid-polymer nanoparticles provide a solution of biocompatible nanocarrier for cancer targeting therapy.

Development of a novel cholesterol tag-based system for trans-membrane transport of protein drugs.

The main technological difficulties of developing an intracellular (transmembrane) transport system for protein drugs lie in two points: i) overcoming the barriers in the cellular membrane, and ii) loading enough protein drugs, and particularly high-dose proteins, into particles. To address these two technological problems, we recently developed a novel cholesterol tag (C-Tag)-based transmembrane transport system. This pilot study found that the C-Tag dramatically improved the cellular uptake of Fab (902-fold, vs. Fab alone) into living cells, indicating that it successfully achieved transmembrane transport. Moreover, C-Tag-mediated membrane transport was verified using micron-scale large unilamellar vesicles (LUVs, approximately 1.5 µm)-based particles. The C-Tagged Fab was able to permeate the liposomal bilayer and it greatly enhanced (a 10.1-fold increase vs. Fab alone) internalization of proteins into the LUV-based particles, indicating that the C-Tag loaded enough proteins into particles for use of high-dose proteins. Accordingly, we established a novel C-Tag-based transport system that has overcome the known technological difficulties of protein transmembrane delivery, and this might be a useful technology for drug development in the future.

Lipid-polymer nanoparticles encapsulating doxorubicin and 2'-deoxy-5-azacytidine enhance the sensitivity of cancer cells to chemical therapeutics.

Nanomedcine holds great potential in cancer therapy due to its flexibility on drug delivery, protection, releasing, and targeting. Epigenetic drugs, such as 2'-deoxy-5-azacytidine (DAC), are able to cause reactive expression of tumor suppressor genes (TSG) in human cancers and, therefore, might be able to enhance the sensitivity of cancer cells to chemotherapy. In this report, we fabricated a lipid-polymer nanoparticle for codelivery of epigenetic drug DAC and traditional chemotherapeutic drug (DOX) to cancer cells and monitored the growth inhibition of the hybrid nanoparticles (NPs) on cancer cells. Our results showed that NPs encapsulating DAC, DOX, or both, could be effectively internalized by cancer cells. More importantly, incorporating DAC into NPs significantly enhanced the sensitivity of cancer cells to DOX by inhibiting cell growth rate and inducing cell apoptosis. Further evidence indicated that DAC encapsulated by NPs was able to rescue the expression of silenced TSG in cancer cells. Overall our work clearly suggested that the resulting lipid-polymer nanoparticle is a potential tool for combining epigenetic therapy and chemotherapy.

Noninvasively immunogenic sonodynamic therapy with manganese protoporphyrin liposomes against triple-negative breast cancer.

Sonodynamic therapy (SDT) is a promising approach for tumor treatment because of the noninvasion, and future would be perfect while it activates systemic immune responses through deep penetration to effectively avoid tumor recurrence. Here, a multifunctional nanosonosensitizer system (FA-MnPs) is designed by encapsulating manganese-protoporphyrin (MnP) into folate-liposomes. The nanoparticles of FA-MnPs not only exhibit excellent depth-responsive SDT but also simultaneously activate SDT-mediated immune response. Under US irradiation, FA-MnPs show the high acoustic intensity in mimic tissue up to 8 cm depth and generate amount of singlet oxygen (1O2). Density functional theory (DFT) calculations reveal that metal coordination in MnP has enhanced the US response ability. The good depth-responsed SDT of FA-MnPs efficiently suppresses the growth of not only the superficial tumors but also the deep lesion in the triple-negative breast cancer (TNBC) mice model. Importantly, FA-MnPs-induced SDT further re-polarizes immunosuppressive M2 macrophages to antitumor M1 macrophages, and elicits immunogenic cell death (ICD) to activate dendritic cells, T lymphocytes, and natural killercells (NK), which consequently trigger the antitumor immune, contributing to the tumor growth inhibition. This study put forward an idea for curing deep-seated and metastatic tumors through noninvasively depth-irradiated immunogenic SDT by reasonably designing multifunctional sonosensitizers.

Synthesis and Characterization of Placental Chondroitin Sulfate A (plCSA)-Targeting Lipid-Polymer Nanoparticles.

An effective cancer therapeutic method reduces and eliminates tumors with minimal systemic toxicity. Actively targeting nanoparticles offer a promising approach to cancer therapy. The glycosaminoglycan placental chondroitin sulfate A (plCSA) is expressed on a wide range of cancer cells and placental trophoblasts, and malarial protein VAR2CSA can specifically bind to plCSA. A reported placental chondroitin sulfate A binding peptide (plCSA-BP), derived from malarial protein VAR2CSA, can also specifically bind to plCSA on cancer cells and placental trophoblasts. Hence, plCSA-BP-conjugated nanoparticles could be used as a tool for targeted drug delivery to human cancers and placental trophoblasts. In this protocol, we describe a method to synthesize plCSA-BP-conjugated lipid-polymer nanoparticles loaded with doxorubicin (plCSA-DNPs); the method consists of a single sonication step and bioconjugate techniques. In addition, several methods for characterizing plCSA-DNPs, including determining their physicochemical properties and cellular uptake by placental choriocarcinoma (JEG3) cells, are described.

NIR-driven Smart Theranostic Nanomedicine for On-demand Drug Release and Synergistic Antitumour Therapy.

Smart nanoparticles (NPs) that respond to external and internal stimulations have been developing to achieve optimal drug release in tumour. However, applying these smart NPs to attain high antitumour performance is hampered by limited drug carriers and inefficient spatiotemporal control. Here we report a noninvasive NIR-driven, temperature-sensitive DI-TSL (DOX/ICG-loaded temperature sensitive liposomes) co-encapsulating doxorubicin (DOX) and indocyanine green (ICG). This theranostic system applies thermo-responsive lipid to controllably release drug, utilizes the fluorescence (FL) of DOX/ICG to real-time trace the distribution of NPs, and employs DOX/ICG to treat cancer by chemo/photothermal therapy. DI-TSL exhibits uniform size distribution, excellent FL/size stability, enhanced response to NIR-laser, and 3 times increased drug release through laser irradiation. After endocytosis by MCF-7 breast adenocarcinoma cells, DI-TSL in cellular endosomes can cause hyperthermia through laser irradiation, then endosomes are disrupted and DI-TSL 'opens' to release DOX simultaneously for increased cytotoxicity. Furthermore, DI-TSL shows laser-controlled release of DOX in tumour, enhanced ICG and DOX retention by 7 times and 4 times compared with free drugs. Thermo-sensitive DI-TSL manifests high efficiency to promote cell apoptosis, and completely eradicate tumour without side-effect. DI-TSL may provide a smart strategy to release drugs on demand for combinatorial cancer therapy.

Improving drug accumulation and photothermal efficacy in tumor depending on size of ICG loaded lipid-polymer nanoparticles.

A key challenge to strengthen anti-tumor efficacy is to improve drug accumulation in tumors through size control. To explore the biodistribution and tumor accumulation of nanoparticles, we developed indocyanine green (ICG) loaded poly (lactic-co-glycolic acid) (PLGA) -lecithin-polyethylene glycol (PEG) core-shell nanoparticles (INPs) with 39 nm, 68 nm and 116 nm via single-step nanoprecipitation. These INPs exhibited good monodispersity, excellent fluorescence and size stability, and enhanced temperature response after laser irradiation. Through cell uptake and photothermal efficiency in vitro, we demonstrated that 39 nm INPs were more easily be absorbed by pancreatic carcinoma tumor cells (BxPC-3) and showed better photothermal damage than that of 68 nm and 116 nm size of INPs. Simultaneously, the fluorescence of INPs offered a real-time imaging monitor for subcellular locating and in vivo metabolic distribution. Near-infrared imaging in vivo and photothermal therapy illustrated that 68 nm INPs showed the strongest efficiency to suppress tumor growth due to abundant accumulation in BxPC-3 xenograft tumor model. The findings revealed that a nontoxic, size-dependent, theranostic INPs model was built for in vivo cancer imaging and photothermal therapy without adverse effect.

Polypeptide cationic micelles mediated co-delivery of docetaxel and siRNA for synergistic tumor therapy.

Combination of two or more therapeutic strategies with different mechanisms can cooperatively impede tumor growth. Co-delivery of chemotherapeutic drug and small interfering RNA (siRNA) within a single nanoparticle (NP) provides a rational strategy for combined cancer therapy. Here, we prepared polypeptide micelle nanoparticles (NPs) of a triblock copolymer poly(ethylene glycol)-b-poly(l-lysine)-b-poly(l-leucine) (PEG-PLL-PLLeu) to systemically codeliver docetaxel (DTX) and siRNA-Bcl-2 for an effective drug/gene vector. The hydrophobic PLLeu core entrapped with anticancer drugs, while the PLL polypeptide cationic backbone allowed for electrostatic interaction with the negatively charged siRNA. The resulting micelle NP exhibited very stable, good biocompatible and excellent passive targeted properties. The micelle complexes with siRNA-Bcl-2 effectively knocked down the expression of Bcl-2 mRNA and protein. Moreover, the co-delivery system of DTX and siRNA-Bcl-2 (DTX-siRNA-NPs) obviously down-regulation of the anti-apoptotic Bcl-2 gene and enhanced antitumor activity with a smaller dose of DTX, resulting the significantly inhibited tumor growth of MCF-7 xenograft murine model as compared to the individual siRNA and only DTX treatments. Our results demonstrated well-defined PEG-PLL-PLLeu polypeptide cationic micelles with the excellent synergistic effect of DTX and siRNA-Bcl-2 in combined cancer therapy.

Single-step assembly of DOX/ICG loaded lipid--polymer nanoparticles for highly effective chemo-photothermal combination therapy.

A combination of chemotherapy and photothermal therapy has emerged as a promising strategy for cancer therapy. To ensure the chemotherapeutic drug and photothermal agent could be simultaneously delivered to a tumor region to exert their synergistic effect, a safe and efficient delivery system is highly desirable. Herein, we fabricated doxorubicin (DOX) and indocyanine green (ICG) loaded poly(lactic-co-glycolic acid) (PLGA)-lecithin-polyethylene glycol (PEG) nanoparticles (DINPs) using a single-step sonication method. The DINPs exhibited good monodispersity, excellent fluorescence/size stability, and consistent spectra characteristics compared with free ICG or DOX. Moreover, the DINPs showed higher temperature response, faster DOX release under laser irradiation, and longer retention time in tumor. In the meantime, the fluorescence of DOX and ICG in DINPs was also visualized for the process of subcellular location in vitro and metabolic distribution in vivo. In comparison with chemo or photothermal treatment alone, the combined treatment of DINPs with laser irradiation synergistically induced the apoptosis and death of DOX-sensitive MCF-7 and DOX-resistant MCF-7/ADR cells, and suppressed MCF-7 and MCF-7/ADR tumor growth in vivo. Notably, no tumor recurrence was observed after only a single dose of DINPs with laser irradiation. Hence, the well-defined DINPs exhibited great potential in targeting cancer imaging and chemo-photothermal therapy.

PEI protected aptamer molecular probes for contrast-enhanced in vivo cancer imaging.

Aptamers have emerged as promising molecular probes for cancer diagnosis. However, their application for in vivo cancer imaging remains limitation due to the poor stability in blood and the degradation by nucleases. In the present study, we generated PEI/aptamer molecular complexes for cancer imaging in vivo by using deoxyribonuclease (DNase)-activatable fluorescence probes (DFProbes) to monitor DNA degradation. The results showed that the complexes with PEI at the N/P ratio from 3.8 to 15 effectively prevented the degradation of DFProbes both in vitro and in vivo. Moreover, PEI successfully protected TD05 aptamers from DNase degradation without affecting its specific recognition of Ramos cells. In tumor bearing mice, PEI/aptamer molecular complexes further demonstrated superior passive tumor targeting and extended circulation time as compared with free aptamer. Hence, the well-defined PEI/aptamer probe is a novel strategy to deliver targeted aptamer for tumor diagnosis and imaging in vivo.