Construction and application of therapeutic metal-polyphenol capsule for peripheral artery disease.

Lesions of patients with peripheral artery disease (PAD) are in a harmful microenvironment, which features increased oxidative stress and inflammatory infiltration. Hence, it is essential to improve the microenvironment along with angiogenesis. In this study, metal-polyphenol capsules (Cu-EGCG), which combines the therapeutic anti-inflammatory and antioxidant activities of EGCG and the angiogenic activity of copper ions, were synthesized through coordination between EGCG and copper ions. The sustained release of the copper ions from Cu-EGCG was demonstrated in vitro, and biocompatible Cu-EGCG can scavenge intracellular ROS, reduce cell death in the presence of cytotoxic levels of ROS, and decrease the expression of pro-inflammatory cytokines (TNF-α, IL-6). Moreover, Cu-EGCG induced the secretion of vascular endothelial growth factor (VEGF) in a hindlimb ischaemia model of PAD. More importantly, the upregulated expression of platelet endothelial cell adhesion molecule-1 (CD31) and proliferating cell nuclear antigen (PCNA) in ischaemic tissues indicated the remarkable effect of Cu-EGCG on angiogenesis. In addition, Cu-EGCG showed significant blood recovery in ischaemic hindlimbs. Taking these results together, biocompatible Cu-EGCG with therapeutic functions holds great potential applications for PAD therapy.

Antigen-Inorganic Hybrid Flowers-Based Vaccines with Enhanced Room Temperature Stability and Effective Anticancer Immunity.

Particle-based antigen carriers as adjuvants play an important role in vaccine development. Herein, an antigen-inorganic hybrid flower-like particle is developed as a novel vaccine carrier. Model antigen ovalbumin (OVA)-copper (II) sulfate hybrid vaccines (OVA-Cu-HVs) are mildly and facilely constructed through a biomimetic mineralization process. OVA-Cu-HVs facilitate cellular uptake in antigen-presenting cells and the internalization of OVA-Cu-HVs involves macropinocytosis-mediated endocytosis. OVA-Cu-HVs can release OVA in a pH-responsive behavior and promote cytosolic release of antigen to enhance antigen cross-presentation. Immunization with OVA-Cu-HVs promotes the maturation of dendritic cells in draining lymph nodes, induces robust antigen-specific T lymphocyte response, and inhibits tumor growth in vivo. In addition, OVA-Cu-HVs are efficacious after being stored for 4 weeks at room temperature and are expected to simplify vaccine storage and lower the cost of cold storage for transportation. Looking forward, OVA-Cu-HVs may hold strong potential to be as an effective vaccine delivery platform, which will facilitate the application of organic-inorganic hybrid flowers in biomedical areas.

A Dual-Model Imaging Theragnostic System Based on Mesoporous Silica Nanoparticles for Enhanced Cancer Phototherapy.

Mesoporous silica nanoparticles (MSNs) show great promise to be exploited as versatile multifunctional nanocarriers for effective cancer diagnosis and treatment. In this work, perfluorohexane (PFH)-encapsulated MSNs with indocyanine green (ICG)-polydopamine (PDA) layer and poly(ethylene glycol)-folic acid coating (designated as MSNs-PFH@PDA-ICG-PEG-FA) are successfully fabricated to achieve tumor ultrasonic (US)/near-infrared fluorescence (NIRF) imaging as well as photothermal therapy (PTT)/photodynamic therapy (PDT). MSNs-PFH@PDA-ICG-PEG-FA exhibits good monodispersity with high ICG loading, significantly enhances ICG photostability, and greatly improves cellular uptake. Upon single 808 nm NIR irradiation, the nanocarrier not only efficiently generates hyperthermia to realize PTT, but also produces reactive oxygen species (ROS) for effective PDT. Meanwhile, NIR irradiation can trigger PFH to undergo vaporization and provide a super-resolution US image. Thus, the PTT/PDT combination therapy can be dually guided by PFH-induced US imaging and ICG-induced NIRF imaging. In vivo antitumor studies demonstrate that PTT/PDT from MSNs-PFH@PDA-ICG-PEG-FA significantly inhibits tumor growth and achieves a cure rate of 60% (three out of five mice are completely cured). Hence, the multifunctional MSNs appear to be a promising theragnostic nanoplatform for multimodal cancer imaging and therapy.

Chitosan/calcium phosphates nanosheet as a vaccine carrier for effective cross-presentation of exogenous antigens.

Chitosan/calcium phosphate nanosheet as a promising antigen carrier was prepared via the direct mixture of modified chitosan, PBS and CaCl2. Specifically, chitosan was modified with catechol groups, and its water solubility under neutral conditions was improved. Then, nanosheet was formed by mixing modified chitosan and PBS followed by addition of CaCl2. Antigen was entrapped into the nanosheet via coprecipitation during its preparation. The nanosheet composed of CaHPO4·2H2O crystals, was internalized by dendritic cells (DCs) via macropinocytosis with enhanced efficiency. The antigen endosomal escape induce by nanosheet was successful observed with intracellular Lysotracker and Lamp-1 staining. Moreover, DCs activation was triggered by the nanosheet along with the up-regulated expression of co-stimulation marker and production of Th1-type cytokines. More importantly, cross-presentation of antigens achieved by the nanosheet was markedly increased when compared to free antigen. Therefore, chitosan/calcium phosphate nanosheet could be used as a vaccine carrier for effective cross-presentation of exogenous antigens.

A Generic Coordination Assembly-Enabled Nanocoating of Individual Tumor Cells for Personalized Immunotherapy.

A generic and effective tumor cells encapsulation strategy enabled by metal-organic coordination is developed to prepare a vaccine for personalized immunotherapy. Specifically, an epigallocatechin-3-gallate (EGCG)-Al(III) coordination layer is in situ formed onto individual living cells in aqueous phase and the process can be completed within an hour. 98% of proteins in the cells are entrapped within the microparticles, which are endowed with high antigens loading capacity. The microparticles enhance the uptake efficiency of antigens, protect antigens from degradation in vivo, and delay the retention time of antigens in the lymph nodes. Moreover, dendritic cells (DCs) activation is triggered by the microparticles, and simultaneously, the expression of costimulation marker on DCs and the production of Th1-related cytokines are significantly upregulated. Moreover, six kinds of tumor cells are utilized and successfully coated with the EGCG/Al(III) layer, suggesting the generalization of this strategy. More importantly, the microparticles exhibit a comparative antitumor effect with polyinosinic-polycytidylic acid (PolyI:C) in B16 pulmonary metastasis model. Overall, the encapsulation strategy enabled by metal-organic coordination can be potentially useful for personalized immunotherapy customized to individual patient's tumor cells.

Targeted Codelivery of an Antigen and Dual Agonists by Hybrid Nanoparticles for Enhanced Cancer Immunotherapy.

Among approaches of current cancer immunotherapy, a dendritic cell (DC)-targeted vaccine based on nanotechnology could be a promising way to efficiently induce potent immune responses. To enhance DC targeting and vaccine efficiency, we included imiquimod (IMQ), a toll-like receptor 7/8 (TLR 7/8) agonist, and monophosphoryl lipid A (MPLA), a TLR4 agonist, to synthesize lipid-polymer hybrid nanoparticles using PCL-PEG-PCL and DOTAP (IMNPs) as well as DSPE-PEG-mannose (MAN-IMNPS). The spatiotemporal delivery of MPLA (within the outer lipid layer) to extracellular TLR4 and IMQ (in the hydrophobic core of NPs) to intracellular TLR7/8 can activate DCs synergistically to improve vaccine efficacy. Ovalbumin (OVA) as a model antigen was readily absorbed by positively charged DOTAP and showed a quick release in vitro. Our results demonstrated that this novel nanovaccine enhanced cellular uptake, cytokine production, and maturation of DCs. Compared with the quick metabolism of free OVA-agonists, the depot effect of OVA-IMNPs was observed, whereas MAN-OVA-IMNPs promoted trafficking to secondary lymphoid organs. After immunization with a subcutaneous injection, the nanovaccine, especially MAN-OVA-IMNPs, induced more antigen-specific CD8+ T cells, greater lymphocyte activation, stronger cross-presentation, and more generation of memory T cells, antibody, IFN-γ, and granzyme B. Prophylactic vaccination of MAN-OVA-IMNPs significantly delayed tumor development and prolonged the survival in mice. The therapeutic tumor challenge indicated that MAN-OVA-IMNPs prohibited tumor progression more efficiently than other formulations, and the combination with an immune checkpoint blockade further enhanced antitumor effects. Hence, the DC-targeted vaccine codelivery with IMQ and MPLA adjuvants by hybrid cationic nanoparticles in a spatiotemporal manner is a promising multifunctional antigen delivery system in cancer immunotherapy.

Co-delivery of antigen and dual agonists by programmed mannose-targeted cationic lipid-hybrid polymersomes for enhanced vaccination.

Exploiting Toll-like receptor (TLR) agonists or their certain combinations can enhance the immune potency of subunit vaccine. Nevertheless, the design of co-delivery systems which can act in a synergistic and spatio-temporal way to achieve effective and durable specific immune response is still challenging. Here we fabricated mannose-functionalized lipid-hybrid polymersomes (MAN-IMO-PS) for co-delivery of ovalbumin antigen both inside the inner core and outside the lipid layer, TLR7/8 agonist imiquimod within the hydrophobic membrane, TLR4 agonist monophosphoryl lipid A in the lipid layer as programmed nanovaccine to synergistically activate immune responses for improving vaccine efficacy. After efficiently internalized by dendritic cells via mannose targeting and TLR4 ligating, MAN-IMO-PS significantly enhanced cross-presentation and cytokine production. In addition, MAN-IMO-PS showed depot effect at the injection site and enhanced migration to draining lymph nodes. Mice immunized with MAN-IMO-PS elicited greater lymphocyte activation, CD4+ and CD8+ T cell response, effector cytokines secretion, and induced Th-1 biased humoral responses. More importantly, prophylactic vaccination by MAN-IMO-PS significantly delayed tumor occurrence, suppressed tumor growth with prolonged survival, and achieved long-term immune effect. The present study demonstrates a rationally designed nanovaccine for combining antigen, different TLR agonists, and targeting moiety in a programmed manner to induce synergistic antitumor immune response.

Alum-functionalized graphene oxide nanocomplexes for effective anticancer vaccination.

Aluminum-based adjuvant (e.g., aluminum oxyhydroxide (AlO(OH), known as the commercial Alhydrogel® (Alum)) is the first adjuvant to be used in human vaccines. Although Alum shows a robust induction of antibody-mediated immunity, its weak stimulation of cell-mediated immunity makes it a questionable adjuvant for cancer immunotherapy. Herein, we described a novel formulation of Alum-based adjuvant by preparing AlO(OH)-modified graphene oxide (GO) nanosheets (GO-AlO(OH)), which, in addition to maintaining the induction of humoral immune response by AlO(OH), could further elicit the cellular immune response by GO. Similar to Alum, GO-AlO(OH) vaccine formulation could be constructed by the incorporation of antigen using a facile mixing/adsorption approach. Antigen-loaded GO-AlO(OH) nanocomplexes facilitated cellular uptake and cytosolic release of antigens and promoted DC maturation, thereby eliciting higher antigen-specific IgG titers, inducing robust CD4+ and CD8+ T lymphocyte response, and inhibiting tumor growth in vivo. Furthermore, by employing tumor cell lysate-based cancer vaccines, GO-AlO(OH) nanocomplexes led to significant inhibition of tumor growth and can be implemented as a personalized treatment strategy for cancer vaccine development. Overall, GO-AlO(OH) nanocomplexes described herein may serve as a facile and efficient approach for effective anticancer vaccination. STATEMENT OF SIGNIFICANCE: Herein, we described a novel formulation of aluminum-based adjuvant by preparing aluminum oxyhydroxide (AlO(OH)) (known as "Alum")-modified graphene oxide (GO) nanocomplexes (GO-AlO(OH)), which, in addition to maintaining the induction of humoral immune response by AlO(OH), could further elicit the cellular immune response by GO. GO-AlO(OH) nanocomplexes can be prepared easily and in large scale by a chemical precipitation method. Similar to "Alum," antigen-loaded GO-AlO(OH) vaccine formulation could be constructed by the incorporation of antigen using a facile mixing/adsorption approach. The very simple and reproductive preparation process of vaccines and the powerful ability to raise both humoral and cellular immune responses provide a novel approach for improving cancer immunotherapy efficacy.

Nanoscale Reduced Graphene Oxide-Mediated Photothermal Therapy Together with IDO Inhibition and PD-L1 Blockade Synergistically Promote Antitumor Immunity.

Despite the potential efficacy of immune checkpoint blockade for effective treatment of cancer, this therapeutic modality is not generally curative, and only a fraction of patients respond. Combination approaches provide strategies to target multiple antitumor immune pathways to induce synergistic antitumor immunity. Here, a multi-combination immunotherapy, including photothermal therapy (PTT), indoleamine-2,3-dioxygenase (IDO) inhibition, and programmed cell death-ligand 1 (PD-L1) blockade, is introduced for inducing synergistic antitumor immunity. We designed a multifunctional IDO inhibitor (IDOi)-loaded reduced graphene oxide (rGO)-based nanosheets (IDOi/rGO nanosheets) with the properties to directly kill tumor cells under laser irradiation and in situ trigger antitumor immune response. In vivo experiments further revealed that the triggered immune response can be synergistically promoted by IDO inhibition and PD-L1 blockade; the responses included the enhancement of tumor-infiltrating lymphocytes, including CD45+ leukocytes, CD4+ T cells, CD8+ T cells, and NK cells; the inhibition of the immune suppression activity of regulator T cells (Tregs); and the production of INF-γ. We also demonstrate that the three combinations of PTT, IDO inhibition, and PD-L1 blockade can effectively inhibit the growth of both irradiated tumors and tumors in distant sites without PTT treatment. This work can be thought of as an important proof of concept to target multiple antitumor immune pathways to induce synergistic antitumor immunity.

Folate-Targeted Redox-Responsive Polymersomes Loaded with Chemotherapeutic Drugs and Tariquidar to Overcome Drug Resistance.

Tumor multidrug resistance (MDR) is a fatal obstacle to cancer chemotherapy. The combination of P-glycoprotein (P-gp) inhibitor and chemotherapeutic drugs is one of the effective strategies to reverse tumor MDR. Herein, a folate-decorated PCL-ss-PEG-ss-PCL based redox-responsive polymersome (FA-TQR-Co-PS) was constructed, which was loaded with P-gp inhibitor tariquidar (TQR), anticancer drugs doxorubicin (DOX) and paclitaxel (PTX). The results suggested that the FA-TQR-Co-PS with an apparent bilayered lamellar structure displayed good monodispersity, high drug loading capacity, superior stability and redox-stimulated drug release peculiarity. In vitro cellular uptake study demonstrated that FA-TQR-Co-PS increased drug accumulation into MCF-7/ADR cells via the TQR-induced P-gp efflux inhibition, and further improved targeting to tumor cells due to folate receptor-mediated endocytosis. Furthermore, the DOX and PTX cytotoxicity and proapoptotic activity against MCF-7/ADR was enhanced dramatically along with the administration of TQR, and the cell cycle was profoundly blocked in G2/M phase. The folate-targeted redox-responsive polymersomes loaded with chemotherapeutic drugs and P-gp inhibitor demonstrated noticeable synergistic effect against human MDR MCF-7 cells and successfully reversed drug resistance, which displayed high potential in overcoming tumor MDR as a novel drug delivery system.

Bubble-generating polymersomes loaded with both indocyanine green and doxorubicin for effective chemotherapy combined with photothermal therapy.

The combination of chemotherapy and photothermaltherapy (PTT) via stimuli-responsive nanovesicles has great potential in tumor treatment. In the present study, bubble-generating polymersomes, which can generate bubbles in response to low pH or hyperthermia, were fabricated to simultaneously encapsulate chemotherapeutic drug and photosensitizing agent for the synergistic chemo-photothermal tumor therapy. Photosensitizer indocyanine green (ICG) was encapsulated into the bilayer of polymersomes formed by amphiphilic triblock copolymer PCL8000-PEG8000-PCL8000 through thin film re-hydration method, while chemotherapeutic doxorubicin (DOX) was loaded into the hydrophilic lumen using a transmembrane ammonium bicarbonate gradient loading procedure. Under acidic condition or laser irradiation, the ammonium bicarbonate (NH4HCO3) encapsulated in the bubble-generating DOX-ICG-co-delivery polymersomes (BG-DIPS) would decompose to produce CO2 bubbles, resulting in destruction of vesicle structure and rapid drug release. In vitro drug release study confirmed that acidic environment and NIR laser irradiation could accelerate DOX release from the BG-DIPS. Cellular uptake study indicated that laser-induced hyperthermia highly enhanced endocytosis of BG-DIPS into 4T1-Luc cancer cells. In vitro cytotoxicity study demonstrated that BG-DIPS exhibited much higher cytotoxicity than free drugs under laser irradiation. In vivo biodistribution study indicated that BG-DIPS could accumulate in the tumor region, prolong drug retention, and increase photothermal conversion efficiency. Furthermore, in vivo antitumor study showed that BG-DIPS with laser irradiation efficiently inhibited 4T1-Luc tumor growth with reduced systemic toxicity. Hence, the formulated bubble-generating polymersomes system was a superior multifunctional nanocarrier for stimuli-response controlled drug delivery and combination chemo-photothermal tumor therapy. STATEMENT OF SIGNIFICANCE: The combination of chemotherapy and photothermaltherapy via stimuli-responsive nanovesicles has great potential in tumor treatment. Herein, bubble-generating polymersomes, which can generate bubbles in response to low pH or hyperthermia, were fabricated to simultaneously encapsulate chemotherapeutic drug (DOX) and photosensitizing agent (ICG) for the synergistic chemo-photothermal tumor therapy. The results in vitro and in vivo demonstrated that bubble-generating DOX-ICG-co-delivery polymersomes (BG-DIPS) would accelerate DOX release from the BG-DIPS and accumulate in the tumor region, prolong drug retention, and increase photothermal conversion efficiency. BG-DIPS with laser irradiation could efficiently inhibited 4T1-Luc tumor growth with reduced systemic toxicity. Hence, the formulated bubble-generating polymersomes system was a superior multifunctional nanocarrier for stimuli-response controlled drug delivery and combination chemo-photothermal tumor therapy.

Dual pH/reduction-responsive hybrid polymeric micelles for targeted chemo-photothermal combination therapy.

The combination of chemotherapy and photothermal therapy in multifunctional nanovesicles has emerged as a promising strategy to improve cancer therapeutic efficacy. Herein, we designed new pH/reduction dual-responsive and folate decorated polymeric micelles (FA Co-PMs) as theranostic nanocarrier to co-encapsulate doxorubicin (DOX) and indocyanine green (ICG) for targeted NIR imaging and chemo-photothermal combination therapy. The Co-PMs exhibited nano-sized structure (∼100 nm) with good monodispersity, high encapsulation efficiency of both ICG and DOX, triggered DOX release in response to acid pH and reduction environment, and excellent temperature conversion with laser irradiation. In vitro cellular uptake study indicated FA Co-PMs achieved significant targeting to BEL-7404 cells via folate receptor-mediated endocytosis, and laser-induced hyperthermia further enhanced drug accumulation into cancer cells. In vivo biodistribution study indicated that FA Co-PMs prolonged drug circulation and enhanced drug accumulation into the tumor via EPR effect and FA targeting. Furthermore, the ICG-based photo-triggered hyperthermia combined with DOX-based chemotherapy synergistically induced the BEL-7404 cell death and apoptosis, and efficiently suppressed the BEL-7404 xenografted tumor growth while significantly reduced systemic toxicity in vivo. Therefore, the designed dual-responsive Co-PMs were promising theranostic nanocarriers for versatile antitumor drug delivery and imaging-guided cancer chemo-photothermal combination therapy. STATEMENT OF SIGNIFICANCE: The combination of chemotherapy and photothermal therapy in multifunctional nanovesicles has emerged as a promising strategy to improve cancer therapeutic efficacy. Herein, we designed novel pH/reduction dual-responsive and folate decorated polymeric micelles (FA Co-PMs) as theranostic nanocarrier to co-encapsulate doxorubicin (DOX) and indocyanine green (ICG) for targeted NIR imaging and chemo-photothermal combination therapy. The Co-PMs triggered DOX release in response to acid pH and reduction environment and exhibited excellent temperature conversion with laser irradiation. The results indicated FA Co-PMs achieved significant targeting to BEL-7404 cells in vitro and efficiently suppressed the BEL-7404 xenografted tumor growth while significantly reduced systemic toxicity in vivo. Therefore, the designed dual-responsive Co-PMs displayed great potential in imaging-guided cancer chemo-photothermal combination therapy as theranostic nanocarriers.

Improved vaccine-induced immune responses via a ROS-triggered nanoparticle-based antigen delivery system.

Subunit vaccines that are designed based on recombinant antigens or peptides have shown promising potential as viable substitutes for traditional vaccines due to their better safety and specificity. However, the induction of adequate in vivo immune responses with appropriate effectiveness remains a major challenge for vaccine development. More recently, the implementation of a nanoparticle-based antigen delivery system has been considered a promising approach to improve the in vivo efficacy for subunit vaccine development. Thus, we have designed and prepared a nanoparticle-based antigen delivery system composed of three-armed PLGA, which is conjugated to PEG via the peroxalate ester bond (3s-PLGA-PO-PEG) and PEI as a cationic adjuvant (PPO NPs). It is known that during a foreign pathogen attack, NADPH, an oxidase, of the host organism is activated and generates an elevated level of reactive oxygen species, hydrogen peroxide (H2O2) primarily, as a defensive mechanism. Considering the sensitivity of the peroxalate ester bond to H2O2 and the cationic property of PEI for the induction of immune responses, this 3s-PLGA-PO-PEG/PEI antigen delivery system is expected to be both ROS responsive and facilitative in antigen uptake without severe toxicity that has been reported with cationic adjuvants. Indeed, our results demonstrated excellent loading capacity and in vitro stability of the PPO NPs encapsulated with the model antigen, ovalbumin (OVA). Co-culturing of bone marrow dendritic cells with the PPO NPs also led to enhanced dendritic cell maturation, antigen uptake, enhanced lysosomal escape, antigen cross-presentation and in vitro CD8+ T cell activation. In vivo experiments using mice further revealed that the administration of the PPO nanovaccine induced robust OVA-specific antibody production, upregulation of splenic CD4+ and CD8+ T cell proportions as well as an increase in memory T cell generation. In summary, we report here a ROS-triggered nanoparticle-based antigen delivery system that could be employed to promote the in vivo efficacy of vaccine-induced immune responses.

ROS-responsive capsules engineered from green tea polyphenol-metal networks for anticancer drug delivery.

Reactive oxygen species (ROS)-responsive nanocapsules for cancer drug delivery were engineered from green tea polyphenol-metal networks. Briefly, DOX-doped ZIF-8 nanoparticles were synthesized via coprecipitation and coated with a layer of EGCG-Fe(iii) complexes by suspending in EGCG and ferric chloride aqueous solutions under mild conditions. The DOX-encapsulating EGCG/Fe nanocapsules (DOX@EGCG/Fe NCs) with a diameter of 399 nm were obtained after template removal. The as-prepared EGCG/Fe NCs can reduce ROS potential accompanied by their degradation. Moreover, DOX@EGCG/Fe NCs can be quickly internalized by cancer cells, and then the intracellular drug release was greatly accelerated in response to overproduced ROS of tumor. Owing to higher ROS levels inside tumor cells compared with normal cells, DOX@EGCG/Fe NCs cause selective cytotoxicity for tumor cells over normal cells. Furthermore, the cytotoxicity of DOX@EGCG/Fe NCs was increased with the increasing incubation time with cancer cells, whereas the tendency of free DOX was reversed. Accordingly, DOX@EGCG/Fe NCs demonstrate good tumor growth inhibition (84.2%) with minor systemic toxicity, which would be a promising candidate for B16 melanoma therapy. Hopefully, our approach could be extended to many other delivery systems such as water soluble/insoluble drugs, gene and protein due to the diversity of polyphenol-metal networks and ZIF-8 templates.

Bilayered Nanoparticles with Sequential Release of VEGF Gene and Paclitaxel for Restenosis Inhibition in Atherosclerosis.

Complete reendothelialization followed by inhibition of smooth muscle cell (SMC) proliferation is considered as an effective therapeutic option to prevent restenosis. We have designed poly(lactide-co-glycolide)-loaded bilayered nanoparticles (NPs) with the ability to sequentially release vascular endothelial growth factor (VEGF)-encoding plasmids from the outer layer and paclitaxel (PTX) from the core to promote endothelial regeneration as well as prevent restenosis. Comparing with conventional NPs, which release VEGF plasmid and PTX simultaneously, we expect that the bilayered NPs could release the VEGF plasmid more rapidly, followed by a delayed release of PTX, resulting in an efficient VEGF gene transfection, which ideally could promote reendothelialization and inhibit excessive SMC growth. Indeed, in the present study, we have observed efficient gene transfection using a model plasmid as well as cell growth attenuation in vitro using Chinese hamster ovary cells. Therapeutic efficacy of the bilayered NPs on restenosis was further evaluated in vivo using a rabbit model of atherosclerosis. The bilayered NPs were administered locally via balloon angioplasty to the injured aortic wall through perfusion. Twenty-eight days after the NP administration, rabbits treated with the bilayered NPs exhibited rapid reendothelialization and inhibition of restenosis, as demonstrated by histological analysis. Increased level of VEGF and decreased level of C-reactive protein, a biological marker that is closely related to atherosclerosis, were also observed from animals treated with the bilayered NPs, implicating ameliorated atherosclerosis. Our results suggest that the VEGF plasmid-/PTX-loaded bilayered NPs exert a beneficial impact on atherosclerotic restenosis by sequentially releasing VEGF and PTX in vivo.

Folate-targeted polymersomes loaded with both paclitaxel and doxorubicin for the combination chemotherapy of hepatocellular carcinoma.

Combination chemotherapy is a promising method of improving cancer treatment, but the distinct pharmacokinetics of combined drugs and non-specific drug distribution slow down the development in the clinic. In this study, folate (FA) receptor-targeted polymersomes with apparent bilayered lamellar structure were successfully developed to co-encapsulate a hydrophobic-hydrophilic chemotherapeutic drug pair (PTX and DOX) in a single vesicle for enhancing the combination chemotherapeutic effect. Hydrophobic PTX was loaded into the thick hydrophobic lamellar membrane by the self-assembly of triblock copolymer PCL8000-PEG8000-PCL8000, while hydrophilic DOX was encapsulated into the hydrophilic reservoir using a trans-membrane ammonium sulfate gradient method. In vitro release study indicated that the drugs were released from the polymersomes in a controlled and sustained manner. Cellular uptake study indicated that FA-targeted Co-PS had higher internalization efficiency in FA receptor-overexpressing BEL-7404 cells than non-targeted Co-PS. In vitro cytotoxicity assay demonstrated that FA-targeted Co-PS exhibited less cytotoxic effect than free drug cocktail, but suppressed the growth of tumor cells more efficiently than non-targeted Co-PS. Ex vivo imaging biodistribution studies revealed that FA-targeted Co-PS led to highly efficient targeting and accumulation in the BEL-7404 xenograft tumor. Furthermore, the in vivo antitumor study showed that the combination chemotherapy of polymersomes to BEL-7404 tumor via intravenous injection was superior to free drug cocktail treatment, and the FA-targeted Co-PS exhibited significantly higher tumor growth inhibition than non-targeted Co-PS group. Therefore, the newly developed FA-targeted co-delivery polymersomes hold great promise for simultaneous delivery of multiple chemotherapeutics and would have great potential in tumor-targeting and combination chemotherapy. STATEMENT OF SIGNIFICANCE: Combination chemotherapy is a promising method of improving cancer treatment, but the distinct pharmacokinetics of combined drugs and non-specific drug distribution slow down the development in the clinic. In our study, novel folate-targeted co-delivery polymersomes (Co-PS) were successfully developed to encapsulate a hydrophobic-hydrophilic chemotherapeutic drug pair (paclitaxel and doxorubicin) into the different compartments of the vesicle. In vivo studies revealed that the combination chemotherapy of polymersomes to BEL-7404 xenograft tumor via intravenous injection was superior to free drug cocktail treatment, and the FA-targeted Co-PS exhibited significantly higher tumor growth inhibition than non-targeted Co-PS group. Therefore, the newly developed FA-targeted co-delivery polymersomes hold great promise for simultaneous delivery of multiple chemotherapeutics and would have great potential in tumor-targeting and combination chemotherapy.

Coordination polymer nanocapsules prepared using metal-organic framework templates for pH-responsive drug delivery.

A facile, efficient, and versatile approach is presented to synthesize pH-responsive nanocapsules (∼120 nm) by combining the advantages of metal-organic frameworks (MOFs) and metal-organic thin films. ZIF-8 nanoparticles are used as templates on which a thin film coating of iron(III)-catechol complexes is derived from the coordination between dopamine-modified alginate (AlgDA) and iron(III) ions. After the template removal, nanocapsules with a pH-responsive wall are obtained. Doxorubicin (Dox), a typical anticancer drug, is first immobilized in ZIF-8 frameworks through coprecipitation and then encapsulated in nanocapsules after the removal of ZIF-8. The structure of the iron(III)-catechol complex varies with pH value, thus conferring the Dox@Nanocapsules with tailored release behavior in vitro. Cytotoxicity tests illustrate the highly effective cytotoxicity of Dox@Nanocapsules towards cancer cells. This study provides a new method for preparing smart nanocapsules and offers more opportunities for the controlled delivery of drugs.

Nanocapsules engineered from polyhedral ZIF-8 templates for bone-targeted hydrophobic drug delivery.

A novel bone-targeted delivery systems based on nanocapsules was developed utilizing a Zeolitic Imidazolate Framework (ZIF-8) as a template and catechol-modified gelatin as wall material. A targeting ligand was facilely conjugated on the surface of nanocapsules. Simvastatin was encapsulated within the nanocapsules with a loading of 37.9%. Hydroxyapatite binding and in vivo biodistribution of the drug-loaded nanocapsules were investigated.

Synthesis of three-arm block copolymer poly(lactic-co-glycolic acid)-poly(ethylene glycol) with oxalyl chloride and its application in hydrophobic drug delivery.

PURPOSE: Synthesis of star-shaped block copolymer with oxalyl chloride and preparation of micelles to assess the prospect for drug-carrier applications. MATERIALS AND METHODS: Three-arm star block copolymers of poly(lactic-co-glycolic acid) (3S-PLGA)-polyethylene glycol (PEG) were synthesized by ring-opening polymerization, then PEG as the hydrophilic block was linked to the terminal hydroxyl of 3S-PLGA with oxalyl chloride. Fourier-transform infrared (FT-IR) spectroscopy, gel-permeation chromatography (GPC), hydrogen nuclear magnetic resonance (1H-NMR) spectra, and differential scanning calorimetry were employed to identify the structure and properties of 3S-PLGA-PEG. Rapamycin (RPM)-loaded micelles were prepared by solvent evaporation, and pyrene was used as the fluorescence probe to detect the critical micelle concentration of the copolymer. The particle size, distribution, and ζ-potential of the micelles were determined by dynamic light scattering, and the morphology of the RPM-loaded micelles was analyzed by transmission electron microscopy. High-performance liquid chromatography was conducted to analyze encapsulation efficiency and drug-loading capacity, as well as the release behavior of RPM-loaded micelles. The biocompatibility of material and the cytostatic effect of RPM-loaded micelles were investigated by Cell Counting Kit 8 assay. RESULTS: FT-IR, GPC, and 1H-NMR suggested that 3S-PLGA-PEG was successfully synthesized. The RPM-loaded micelles prepared with the 3S-PLGA-PEG possessed good properties. The micelles had good average diameter and encapsulation efficiency. For in vitro release, RPM was released slowly from 3S-PLGA-PEG micelles, showing that 3S-PLGA-PEG-RPM exhibited a better and longer antiproliferative effect than free RPM. CONCLUSION: In this study, we first used oxalyl chloride as the linker to synthesize 3S-PLGA-PEG successfully, and compared with reported literature, this method shortened the reaction procedure and improved the reaction yield. The micelles prepared with this material proved suitable for drug-carrier application.

Recombinant adenovirus of human p66Shc inhibits MCF-7 cell proliferation.

The aim of this work was to construct a human recombinant p66Shc adenovirus and to investigate the inhibition of recombinant p66Shc adenovirus on MCF-7 cells. The recombinant adenovirus expression vector was constructed using the Adeno-X Adenoviral System 3. Inhibition of MCF-7 cell proliferation was determined by MTT. Intracellular ROS was measured by DCFH-DA fluorescent probes, and 8-OHdG was detected by ELISA. Cell apoptosis and the cell cycle were assayed by flow cytometry. Western blot were used to observe protein expression. p66Shc expression was upregulated in 4 cell lines after infection. The inhibitory effect of p66Shc recombinant adenovirus on MCF-7 cells was accompanied by enhanced ROS and 8-OHdG. However, no significant differences were observed in the cell apoptosis rate. The ratio of the cell cycle G2/M phase showed a significant increase. Follow-up experiments demonstrated that the expressions of p53, p-p53, cyclin B1 and CDK1 were upregulated with the overexpression of p66Shc. The Adeno-X Adenoviral System 3 can be used to efficiently construct recombinant adenovirus containing p66Shc gene, and the Adeno-X can inhibit the proliferation of MCF-7 cells by inducing cell cycle arrest at the G2/M phase. These results suggested that p66Shc may be a key target for clinical cancer therapy.