Iron Oxide Nanoparticles Induce Autophagosome Accumulation through Multiple Mechanisms: Lysosome Impairment, Mitochondrial Damage, and ER Stress.

Magnetite (iron oxide, Fe3O4) nanoparticles have been widely used for drug delivery and magnetic resonance imaging (MRI). Previous studies have shown that many metal-based nanoparticles including Fe3O4 nanoparticles can induce autophagosome accumulation in treated cells. However, the underlying mechanism is still not clear. To investigate the biosafety of Fe3O4 and PLGA-coated Fe3O4 nanoparticles, some experiments related to the mechanism of autophagy induction by these nanoparticles have been investigated. In this study, the results showed that Fe3O4, PLGA-coated Fe3O4, and PLGA nanoparticles could be taken up by the cells through cellular endocytosis. Fe3O4 nanoparticles extensively impair lysosomes and lead to the accumulation of LC3-positive autophagosomes, while PLGA-coated Fe3O4 nanoparticles reduce this destructive effect on lysosomes. Moreover, Fe3O4 nanoparticles could also cause mitochondrial damage and ER and Golgi body stresses, which induce autophagy, while PLGA-coated Fe3O4 nanoparticles reduce the destructive effect on these organelles. Thus, the Fe3O4 nanoparticle-induced autophagosome accumulation may be caused by multiple mechanisms. The autophagosome accumulation induced by Fe3O4 was also investigated. The Fe3O4, PLGA-coated Fe3O4, and PLGA nanoparticle-treated mice were sacrificed to evaluate the toxicity of these nanoparticles on the mice. The data showed that Fe3O4 nanoparticle treated mice would lead to the extensive accumulation of autophagosomes in the kidney and spleen in comparison to the PLGA-coated Fe3O4 and PLGA nanoparticles. Our data clarifies the mechanism by which Fe3O4 induces autophagosome accumulation and the mechanism of its toxicity on cell organelles and mice organs. These findings may have an important impact on the clinical application of Fe3O4 based nanoparticles.

Doxorubicin-loaded star-shaped copolymer PLGA-vitamin E TPGS nanoparticles for lung cancer therapy.

A doxorubicin-loaded mannitol-functionalized poly(lactide-co-glycolide)-b-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles (DOX-loaded M-PLGA-b-TPGS NPs) were prepared by a modified nanoprecipitation method. The NPs were characterized by the particle size, surface morphology, particle stability, in vitro drug release and cellular uptake efficiency. The NPs were near-spherical with narrow size distribution. The size of M-PLGA-b-TPGS NPs was ~110.9 nm (much smaller than ~143.7 nm of PLGA NPs) and the zeta potential was -35.8 mV (higher than -42.6 mV of PLGA NPs). The NPs exhibited a good redispersion since the particle size and surface charge hardly changed during 3-month storage period. In the release medium (phosphate buffer solution vs. fetal bovine serum), the cumulative drug release of DOX-loaded M-PLGA-b-TPGS, PLGA-b-TPGS, and PLGA NPs were 76.41 versus 83.11 %, 58.94 versus 73.44 % and 45.14 versus 53.12 %, respectively. Compared with PLGA-b-TPGS NPs and PLGA NPs, the M-PLGA-b-TPGS NPs possessed the highest cellular uptake efficiency in A549 and H1975 cells (lung cancer cells). Ultimately, both in vitro and in vivo antitumor activities were evaluated. The results showed that M-PLGA-b-TPGS NPs could achieve a significantly higher level of cytotoxicity in cancer cells and a better antitumor efficiency on xenograft BALB/c nude mice tumor model than free DOX. In conclusion, the DOX-loaded M-PLGA-b-TPGS could be used as a potential DOX-loaded nanoformulation in lung cancer chemotherapy.

Bioengineered Artificial Extracellular Vesicles Presenting PD-L1 and Gal-9 Ameliorate New-onset Type 1 Diabetes.

An important factor in the development of Type 1 diabetes (T1D) is the deficiency of inhibitory immune checkpoint ligands, specifically programmed cell death ligand 1 (PD-L1) and Galectin-9 (Gal-9), in ß-cells. Hence, modulation of the pancreas infiltrated T lymphocytes by exogenous PD-L1 or Gal-9 is an ideal approach for treating the new-onset T1D. Herein, we genetic engineered the macrophage cells to generate artificial extracellular vesicles (aEVs) overexpressing PD-L1 and Gal-9, which could restrict the islets autoreactive T lymphocytes and protect ß-cells from destruction. Intriguingly, overexpressing Gal-9 spurred macrophage polarization to M2 phenotype with immune suppressive attribute. Alternatively, both of PD-L1 and Gal-9 presenting aEVs (PD-L1-Gal-9 aEVs) favorably adhere to T cells via the interaction of programmed cell death protein 1 (PD-1)/PD-L1 or T cell immunoglobulin mucin 3 (TIM-3)/Gal-9. Moreover, PD-L1-Gal-9 aEVs prominently promoted effector T cell apoptosis and splenic regulatory T cells (Treg) cells differentiation in vitro. Virtually, PD-L1-Gal-9 aEVs efficaciously reversed the new-onset hyperglycemia in the NOD mice, prevented T1D progress, and declined the proportion and activation of CD4+ and CD8+ T cells infiltrating the pancreas notably, which together contributed to preserving the residual ß-cells survival and mitigating the hyperglycemia.

Biosynthetic neoantigen displayed on bacteria derived vesicles elicit systemic antitumour immunity.

Neoantigens derived from mutant proteins in tumour cells could elicit potent personalized anti-tumour immunity. Nevertheless, the layout of vaccine vehicle and synthesis of neoantigen are pivotal for stimulating robust response. The power of synthetic biology enables genetic programming bacteria to produce therapeutic agents under contol of the gene circuits. Herein, we genetically engineered bacteria to synthesize fusion neoantigens, and prepared bacteria derived vesicles (BDVs) presenting the neoantigens (BDVs-Neo) as personalized therapeutic vaccine to drive systemic antitumour response. BDVs-Neo and granulocyte-macrophage colony-stimulating factor (GM-CSF) were inoculated subcutaneously within hydrogel (Gel), whereas sustaining release of BDVs-Lipopolysaccharide (LPS) and GM-CSF recruited the dendritic cells (DCs). Virtually, Gel-BDVs-Neo combined with the programmed cell death protein 1 (PD-1) antibody intensively enhanced proliferation and activation of tumour-infiltrated T cells, as well as memory T cell clone expansion. Consequently, BDVs-Neo combining with checkpoint blockade therapy effectively prevented tumour relapse and metastasis.

Genetic engineering cellular vesicles expressing CD64 as checkpoint antibody carrier for cancer immunotherapy.

Immune checkpoint blockade therapies, especially those targeting the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) have achieved impressive clinical responses in multiple types of cancers. To optimize the therapeutic effect of the checkpoint antibodies, many strategies including targeting delivery, controlled release, and cellular synthesis have been developed. However, within these strategies, antibodies were attached to drug carriers by chemical bonding, which may affect the steric configuration and function of the antibodies. Herein, we prepared cluster of differentiation 64 (CD64), a natural catcher of the fragment crystalline (Fc) of monomeric immunoglobulin G (IgG), and over-expressed it on the cell membrane nanovesicles (NVs) as PD-L1 antibody delivery vehicle (CD64-NVs-aPD-L1), which was employed to disrupt the PD-1/PD-L1 immunosuppressive signal axis for boosting T cell dependent tumor elimination. Meanwhile, chemical immunomodulatory drug cyclophosphamide (CP) was also encapsulated in the vesicle (CD64-NVs-aPD-L1-CP), to simultaneously restrain the regulatory T cells (Tregs) and invigorate Ki67+CD8+ T cells, then further enhance their anti-tumor ability. Methods: The cell membrane NVs overexpressing CD64 were incubated with PD-L1 antibody and chemotherapeutic agent CP to prepare CD64-NVs-aPD-L1-CP. Results: The CD64-NVs-aPD-L1-CP could simultaneously interrupt the immunosuppressive effect of PD-L1 and decrease the inhibition of Tregs, leading to tumor growth suppression and survival time extension. Conclusion: CD64-NVs are charismatic carriers to achieve both checkpoint blockade and immunomodulatory drugs for combined cancer immunotherapy.

Liposomes Encapsulating Neoantigens and Black Phosphorus Quantum Dots for Enhancing Photothermal Immunotherapy.

Colorectal cancer frustrates with high relapse after the traditional treatment including surgery and chemotherapy. Neoantigen-based therapeutic vaccine has achieved high response rate in the clinical trials rising the immunotherapy as a promising alternative for colorectal cancer. Herein, colon cancer cells derived neoantigen peptide Adpgk were employed to be co-encapsulated with black phosphorus quantum dots into liposome (Adpgk-BPQDs-liposome) as therapeutic vaccine. Adpgk-BPQDs-liposome were dispersed in F127 gel containing GM-CSF. The heat generated by black phosphorus (BP) under 808 nm near-infrared laser irradiation accelerates the F127 gel ablation and the release of GM-CSF, which recruit APC cells and prime the native T cells. The tumor bearing mice received the programmed cell death protein 1 (PD-1) checkpoint blockade antibody combined with photo-thermal gel intensively prevented the tumor progress. Furthermore, the tumor infiltrating CD8+ T cells were significantly increased which lead to the elimination of the tumor.

Intracellular Trafficking Network and Autophagy of PHBHHx Nanoparticles and their Implications for Drug Delivery.

3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBHHx), which is naturally generated by biodegradable polyhydroxyalkanoates synthesized by bacteria, is an attractive material for drug delivery due to its controllable physical properties, non-toxicity, environmental friendliness, degradable properties and good biocompatibility. However, the intracellular trafficking network pathways, especially the autophagy mechanism of PHBHHx nanoparticles (NPs), have rarely been investigated. In this paper, we successfully prepared the NPs used solvent displacement method and investigated the autophagy pathways and other intracellular trafficking mechanisms based on NPs with the assistance of Rab proteins. We found that NPs were internalized in cells mainly via clathrin endocytosis and caveolin endocytosis. Beside the classical pathways, we discovered two new pathways: the micropinocytosis early endosome (EEs)-micropinocytosis-lysosome pathway and the EEs-liposome-lysosome pathway. NPs were delivered to cells through endocytosis recycling vesicles and GLUT4 exocytosis vesicles. Similar to other nanoparticles, NPs also induced intracellular autophagy and were then degraded via endolysosomal pathways. 3-MA and CQ were used as autophagy inhibitors to avoid the degradation of NPs through lysosomes by blocking endolysosomal pathways. Tumor volumes and weights were significantly decreased when autophagy inhibitors and chemical drugs packaged in NPs were cooperatively used.

Phosphorylcholine-Based Stealthy Nanocapsules Decorating TPGS for Combatting Multi-Drug-Resistant Cancer.

Improving the anticancer efficacy of chemotherapeutics not only demands for efficient delivery into tumor sites, but also always needs to combat the multidrug resistance of cancer. Here we attempted to conquer both these problems by decorating D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) onto a phosphorylcholine-based stealthy nanocapsule. This TPGS-decorated stealthy nanocapsule, referred as nBSA-TPGS-Dox, conjugated anticancer drug doxorubicin (Dox) through an acid-responsive benzoic-imine bond. nBSA-TPGS-Dox was demonstrated to be stable in PBS and exhibited acid-responsive Dox release behavior. In vitro results showed this nanocapsule could be efficiently uptaken by the Dox-resistant HepG2/ADR human liver cancer cells through clathrin-mediated endocytosis and greatly prevented the Dox efflux, causing much more cytotoxicity than free Dox and non-TPGS-decorated nBSA-Dox. Furthermore, nBSA-TPGS-Dox exhibited much prolonged in vivo half-life compared to conventional PEGylated nanoparticles and achieved excellent tumor accumulation. Finally, this TPGS-decorated stealthy nanocapsule performed outstanding suppression of Dox-resistant tumor, much superior than non TPGS-decorated nBSA-Dox and free Dox. Thus, this TPGS-decorated stealthy nanocapsule provides a novel powerful nanomedicine platform for combatting multi-drug-resistant cancer.

DACHPt-Loaded Nanoparticles Self-assembled from Biodegradable Dendritic Copolymer Polyglutamic Acid-b-D-α-Tocopheryl Polyethylene Glycol 1000 Succinate for Multidrug Resistant Lung Cancer Therapy.

The clinical applications of platinum-based antitumor agents are still largely limited by severe side effects as well as multidrug resistance (MDR). To solve these problems, we developed an 1,2-diaminocyclohexane-platinum(II) (DACHPt)-loaded nanoparticle (NP-TPGS-Pt) by self-assembly of poly(amidoamine)-polyglutamic acid-b-D-α-tocopheryl polyethylene glycol 1000 succinate (PAM-PGlu-b-TPGS) and DACHPt. NP-TPGS-Pt showed robust stability and pH-responsive DACHPt release profile in vitro similar to the PEG-containing nanoparticle (NP-PEG-Pt). Meanwhile, in contrast with NP-PEG-Pt, NP-TPGS-Pt exhibited efficient nanoparticle-based cellular uptake by the Pt-resistant A549/DDP human lung cancer cells and caused much more cytotoxicity than free Oxaliplatin and NP-PEG-Pt. Finally, this NP-TPGS-Pt was proved to perform outstanding inhibition of Pt-resistant tumor growth, much superior than free Oxaliplatin and NP-PEG-Pt. Thus, this NP-TPGS-Pt provides a novel powerful nanomedicine platform for combatting multidrug resistant cancer.

Systematic investigation on the intracellular trafficking network of polymeric nanoparticles.

Polymeric nanoparticles such as PLGA-based nanoparticles are emerging as promising carriers for controlled drug delivery. However, little is known about the intracellular trafficking network of polymeric nanoparticles. Here, more than 30 Rab proteins were used as markers of multiple trafficking vesicles in endocytosis, exocytosis and autophagy to investigate in detail the intracellular trafficking pathways of PLGA nanoparticles. We observed that coumarin-6-loaded PLGA nanoparticles were internalized by the cells mainly through caveolin and clathrin-dependent endocytosis and Rab34-mediated macropinocytosis. Then the PLGA nanoparticles were transported to early endosomes (EEs), late endosomes (LEs), and finally to lysosomes. Two novel transport pathways were identified in our research: the macropinocytosis (Rab34 positive)-LE (Rab7 positive)-lysosome pathway and the EE-liposome (Rab18)-lysosome pathway. Moreover, the slow (Rab11 and Rab35 positive), fast (Rab4 positive) and apical (Rab20 and Rab25 positive) endocytic recycling endosome pathways could transport the PLGA nanoparticles to lysosomes. The PLGA nanoparticles were transported out of the cells by GLUT4 transport vesicles (Rab8, Rab10 positive), classic secretory vesicles (Rab3, Rab27 positive vesicles) and melanosomes (Rab32, Rab38 positive vesicles). Besides, the PLGA nanoparticles were observed in autophagosomes (LC3 positive), which means that the nanoparticles can be delivered by the autophagy pathway. Multiple cross-talk pathways were identified connecting autophagy and endocytosis or exocytosis by screening the co-localization of the Rab proteins with the LC3 protein. Degradation of nanoparticles through lysosomes can be blocked by autophagy inhibitors (3 MA and CQ). A better understanding of intracellular trafficking mechanisms involved in polymeric nanoparticle-based drug delivery is a prerequisite to clinical application.

Investigation and intervention of autophagy to guide cancer treatment with nanogels.

Cancer cells use autophagy to resist poor survival environmental conditions such as low PH, poor nutrients as well as chemical therapy. Nanogels have been used as efficient chemical drug carriers for cancer treatment. However, the effect of nanogels on autophagy is still unknown. Here, we used Rab proteins as the marker of multiple trafficking vesicles in endocytosis and LC3 as the marker of autophagy to investigate the intracellular trafficking network of Rhodamine B (Rho)-labeled nanogels. The nanogels were internalized by the cells through multiple protein dependent endocytosis and micropinocytosis. After inception by the cells, the nanogels were transported into multiple Rab positive vesicles including early endosomes (EEs), late endosomes (LEs), recycling endosomes (REs) and lipid droplets. Finally, these Rab positive vesicles were transported to lysosome. In addition, GLUT4 exocytosis vesicles could transport the nanogels out of the cells. Moreover, nanogels could induce autophagy and be sequestered in autophagosomes. The crosstalk between autophagosomes and Rab positive vesicles were investigated, we found that autophagosomes may receive nanogels through multiple Rab positive vesicles. Co-delivery of autophagy inhibitors such as chloroquine (CQ) and the chemotherapeutic drug doxorubicin (DOX) by nanogels blocked the autophagy induced by DOX greatly decreasing both of the volume and weight of the tumors in mice tumor models. Investigation and intervention of the autophagy pathway could provide a new method to improve the therapeutic effect of anticancer nanogels.

Formation of a Snf1-Mec1-Atg1 Module on Mitochondria Governs Energy Deprivation-Induced Autophagy by Regulating Mitochondrial Respiration.

Autophagy is essential for maintaining glucose homeostasis, but the mechanism by which energy deprivation activates autophagy is not fully understood. We show that Mec1/ATR, a member of the DNA damage response pathway, is essential for glucose starvation-induced autophagy. Mec1, Atg13, Atg1, and the energy-sensing kinase Snf1 are recruited to mitochondria shortly after glucose starvation. Mec1 is recruited through the adaptor protein Ggc1. Snf1 phosphorylates Mec1 on the mitochondrial surface, leading to recruitment of Atg1 to mitochondria. Furthermore, the Snf1-mediated Mec1 phosphorylation and mitochondrial recruitment of Atg1 are essential for maintaining mitochondrial respiration during glucose starvation, and active mitochondrial respiration is required for energy deprivation-activated autophagy. Thus, formation of a Snf1-Mec1-Atg1 module on mitochondria governs energy deprivation-induced autophagy by regulating mitochondrial respiration.

Robust aptamer-polydopamine-functionalized M-PLGA-TPGS nanoparticles for targeted delivery of docetaxel and enhanced cervical cancer therapy.

One limitation of current biodegradable polymeric nanoparticles (NPs) is the contradiction between functional modification and maintaining formerly excellent bioproperties with simple procedures. Here, we reported a robust aptamer-polydopamine-functionalized mannitol-functionalized poly(lactide-co-glycolide) (M-PLGA)-D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoformulation (Apt-pD-NPs) for the delivery of docetaxel (DTX) with enhanced cervical cancer therapy effects. The novel DTX-loaded Apt-pD-NPs possess satisfactory advantages: 1) increased drug loading content and encapsulation efficiency induced by star-shaped copolymer M-PLGA-TPGS; 2) significant active targeting effect caused by conjugated AS1411 aptamers; and 3) excellent long-term compatibility by incorporation of TPGS. Therefore, with simple preparation procedures and excellent bioproperties, the new functionalized Apt-pD-NPs could maximally increase the local effective drug concentration on tumor sites, achieving enhanced treatment effectiveness and minimizing side effects. In a word, the robust DTX-loaded Apt-pD-NPs could be used as potential nanotherapeutics for cervical cancer treatment, and the aptamer-polydopamine modification strategy could be a promising method for active targeting of cancer therapy with simple procedures.

Intracellular Trafficking Network of Protein Nanocapsules: Endocytosis, Exocytosis and Autophagy.

The inner membrane vesicle system is a complex transport system that includes endocytosis, exocytosis and autophagy. However, the details of the intracellular trafficking pathway of nanoparticles in cells have been poorly investigated. Here, we investigate in detail the intracellular trafficking pathway of protein nanocapsules using more than 30 Rab proteins as markers of multiple trafficking vesicles in endocytosis, exocytosis and autophagy. We observed that FITC-labeled protein nanoparticles were internalized by the cells mainly through Arf6-dependent endocytosis and Rab34-mediated micropinocytosis. In addition to this classic pathway: early endosome (EEs)/late endosome (LEs) to lysosome, we identified two novel transport pathways: micropinocytosis (Rab34 positive)-LEs (Rab7 positive)-lysosome pathway and EEs-liposome (Rab18 positive)-lysosome pathway. Moreover, the cells use slow endocytosis recycling pathway (Rab11 and Rab35 positive vesicles) and GLUT4 exocytosis vesicles (Rab8 and Rab10 positive) transport the protein nanocapsules out of the cells. In addition, protein nanoparticles are observed in autophagosomes, which receive protein nanocapsules through multiple endocytosis vesicles. Using autophagy inhibitor to block these transport pathways could prevent the degradation of nanoparticles through lysosomes. Using Rab proteins as vesicle markers to investigation the detail intracellular trafficking of the protein nanocapsules, will provide new targets to interfere the cellular behaver of the nanoparticles, and improve the therapeutic effect of nanomedicine.

Polydopamine-Based Surface Modification of Novel Nanoparticle-Aptamer Bioconjugates for In Vivo Breast Cancer Targeting and Enhanced Therapeutic Effects.

In this study, we reported a simple polydopamine (pD)-based surface modification method to prepare novel nanoparticle-aptamer bioconjugates (Apt-pD-DTX/NPs) for in vivo tumor targeting and enhanced therapeutic effects of breast cancer. With simple preparation procedures, the new functionalized Apt-pD-DTX/NPs could maximumly increase the local effective drug concentration on tumor sites, achieving enhanced treatment effectiveness and minimizing side effects. The dopamine polymerization and aptamer conjugation barely changed the characters of NPs. Both in vitro cell experiments (i.e. endocytosis of fluorescent NPs, in vitro cellular targeting and cytotoxicity assays) and in vivo animal studies (i.e. in vivo imaging, biodistribution and antitumor effects of NPs) demonstrated that the Apt-pD-DTX/NPs could achieve significantly high targeting efficiency and enhanced therapeutic effects compared with clinical Taxotere(®) and NPs without functional modification. Above all, the Apt-pD-DTX/NPs showed great potential as a promising nanoformulation for in vivo breast cancer therapy and the construction of pD-modified NP-aptamer bioconjugates could be of great value in medical use.

Blended nanoparticle system based on miscible structurally similar polymers: a safe, simple, targeted, and surprisingly high efficiency vehicle for cancer therapy.

A novel blended nanoparticle (NP) system for the delivery of anticancer drugs and its surprisingly high efficacy for cancer chemotherapy by blending a targeting polymer folic acid-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (FA-PEG-b-PLGA) and a miscible structurally similar polymer D-α-tocopheryl polyethylene glycol 1000 succinate-poly(lactide-co-glycolide) (TPGS-PLGA) is reported. This blended NP system can be achieved through a simple and effective nanoprecipitation technique, and possesses unique properties: i) improved long-term compatibility brought by PEG-based polymers; ii) reduced multidrug resistance mediated by P-glycoprotein (P-gp) in tumor cells and increased bioavailability of anticancer drugs by incorporation of TPGS; iii) the regulation of controlled release through polymer ratios and active targeting by FA. Both in vitro cell experiments and in vivo antitumor assays demonstrated the reported blended NP system can achieve the best therapeutic efficiency in an extremely safe, simple and highly efficient process for cancer therapy. Moreover, this NP system is highly efficient in forming NPs with multiple functions, without repeated chemical modification of polymers, which is sometimes complex, inefficient and high cost. Therefore, the development of this novel blended NP concept is extremely meaningful for the application of pharmaceutical nanotechnology in recent studies.

Antitumor efficiency of D-alpha-tocopheryl polyethylene glycol 1000 succinate-b-poly(epsilon-caprolactone-ran-lactide) nanoparticle-based delivery of docetaxel in mice bearing cervical cancer.

Pharmaceutical nanotechnology holds potential in cancer chemotherapy. In this research, the docetaxel-loaded D-alpha-tocopheryl polyethylene glycol 1000 succinate-b-poly(epsilon-caprolactone-ran-lactide) (TPGS-b-(PCL-ran-PLA)) nanoparticles were prepared by a modified nanoprecipitation method and then the particle size, surface morphology, nanoparticle stability, in vitro drug release and cellular uptake of nanoparticles were characterized. Finally, we evaluated the therapeutic effects of nanoparticle formulation in comparison with Taxotere both in vitro and in vivo. The size of TPGS-b-(PCL-ran-PLA) nanoparticles was about 150 nm and much smaller than PCL nanoparticles (about 185 nm) and the absolute value of zeta potential was higher than PCL nanoparticles (16.49 mV vs. 13.17 mV). FESEM images further confirmed the morphology and size of nanoparticles. The drug-loaded nanoparticles were considered to be stable, showing no change in the particle size and surface charge during three-month storage of its aqueous solution. In vitro drug release of TPGS-b-(PCL-ran-PLA) nanoparticles was much faster than PCL and PCL-TPGS nanoparticles. The cumulative drug release of docetaxel-loaded TPGS-b-(PCL-ran-PLA), PCL-TPGS, and PCL NPs were 38.00%, 34.48% and 29.04%, respectively. TPGS-b-(PCL-ran-PLA) nanoparticles showed an obvious increase of cellular uptake. Due to the advantages of TPGS-b-(PCL-ran-PLA) nanoparticles, it could achieve significantly higher level of cytotoxicity in vitro and better inhibition effect of tumor growth on xenograft BALB/c nude mice tumor model than commercial Taxotere at the same dose (1.49-fold more effective). The TPGS-b-(PCL-ran-PLA) could be used as a novel and potential biodegradable polymeric material for nanoformulation in cervical cancer chemotherapy.

Synthesis of cholic acid-core poly(ε-caprolactone-ran-lactide)-b-poly(ethylene glycol) 1000 random copolymer as a chemotherapeutic nanocarrier for liver cancer treatment.

A star-shaped random copolymer, cholic acid functionalized poly(ε-caprolactone-ran-lactide)-b-poly(ethylene glycol) 1000 (CA-(PCL-ran-PLA)-b-PEG1k), was synthesized by a core-first approach involving three stages of chemical reactions, and was characterized by hydrogen-1 nuclear magnetic resonance (1H NMR), gel permeation chromatography and thermogravimetric analysis. The docetaxel-loaded nanoparticles (NPs) were prepared by a modified nano-precipitation method. The formation and characterization of these NPs were confirmed through dynamic light scattering, zeta potential measurements, field emission scanning electron microscopy, and transmission electron microscopy. The in vitro release profiles indicated that CA-(PCL-ran-PLA)-b-PEG1k NPs had excellent sustained and controlled drug release properties. Both confocal laser scanning microscope and flow cytometric results showed that the coumarin-6 loaded CA-(PCL-ran-PLA)-b-PEG1k NPs had the highest cellular uptake efficiency compared with PEG1k-b-(PCL-ran-PLA) NPs and CA-(PCL-ran-PLA) NPs in human hepatic carcinoma cells. The docetaxel-loaded CA-(PCL-ran-PLA)-b-PEG1k NPs were also proved to have the highest drug loading content, encapsulation efficiency, and the best anti-tumor efficacy both in vitro and in vivo. In conclusion, the star-shaped CA-(PCL-ran-PLA)-b-PEG1k copolymer was successfully synthesized and could be used as a promising drug-loaded biomaterial for liver cancer chemotherapy.

Co-delivery of chemotherapeutic drugs with vitamin E TPGS by porous PLGA nanoparticles for enhanced chemotherapy against multi-drug resistance.

We report a strategy to make use of poly(lactic-co-glycolic acid) nanoparticle (PLGA NPs) for co-delivery of docetaxel (DTX) as a model anticancer drug together with vitamin E TPGS. The latter plays a dual role as a pore-forming agent in the nanoparticles that may result in smaller particle size, higher drug encapsulation efficiency and faster drug release, and also as a bioactive agent that could inhibit P-glycoprotein to overcome multi-drug resistance of the cancer cells, The DTX-loaded PLGA NPs of 0, 10, 20 and 40% TPGS were prepared by the nanoprecipitation method and then characterized for their size and size distribution, surface morphology, physical status and encapsulation efficiency of the drug in the NPs. All four NPs were found of size ranged 100-120 nm and EE ranged 85-95% at drug loading level around 10%. The in vitro evaluation showed that the 48 h IC50 values of the free DTX and the DTX-loaded PLGA NPs of 0, 10, 20% TPGS were 2.619 and 0.474, 0.040, 0.009 µg/mL respectively, which means that the PLGA NPs formulation could be 5.57 fold effective than the free DTX and that the DTX-loaded PLGA NPs of 10 or 20% TPGS further be 11.85 and 52.7 fold effective than the DTX-loaded PLGA NPs of no TPGS (therefore, 66.0 and 284 fold effective than the free DTX). Xenograft tumor model and immunohistological staining analysis further confirmed the advantages of the strategy of co-delivery of anticancer drugs with TPGS by PLGA NPs.