Efficient TNBC immunotherapy by dual reprogramming tumor-infiltrating dendritic cells and tumor-associated macrophages with stimulus-responsive miR155 nanocomplexes.

Triple negative breast cancer (TNBC) remains to be a formidable adversary with high mortality and unfavorable prognosis. Tumor microenvironment comprises of various constituents, among them, tumor infiltrating dendritic cells (TIDCs) and tumor-associated macrophages (TAMs) which have been recognized as pivotal factors responsible for mediating immune responses. Overcoming the refractory properties of TIDCs and TAMs is critical for inducing a robust and sustained immune response against cancer cells. In this study, pH/ROS-responsive microRNA-155 (miR155) nanocomplexes (MiR@PCPmP NPs) were developed to reprogram TIDCs and TAMs for efficient TNBC immunotherapy. This nanoplatform was based on a pH/ROS cleavable copolymer of poly(ethylene glycol)-carboxydimethyl maleate-poly(ethyleneimine)-peroxalate ester-poly(ε-caprolactone) grafted with mannose moieties (PEG-CDM-PEI[Man]-ox-PCL) which self-assembled with miRNA to form nanocomplexes. In the tumor microenvironment, the nanocomplexes showed selective cellular uptake by TIDCs and TAMs through PEG detachment and mannose exposure, followed by efficient endosomal escape, cytosolic miR155 release, and the dual-reprogramming of TIDCs and TAMs. Our results showed that MiR@PCPmP NPs significantly improved antitumor immune responses with highly infiltrating CD8+ T cells while restraining immunosuppressive components in 4T1 tumor-bearing mice. Furthermore, the nanoparticles effectively suppressed both primary tumors and pulmonary metastatic nodules without obvious systemic toxicity. This research highlights the potential of dual-reprogramming of TIDCs and TAMs with the miR155 nanocomplexes as a promising strategy for TNBC immunotherapy, with potential for translation to other cancers with a similar microenvironment.

Codelivery of Que and BCL-2 siRNA with Lipid-Copolymer Hybrid Nanocomplexes for Efficient Tumor Regression.

The efficacy of chemotherapy is often reduced due to the chemotherapy resistance of tumor cells, which is usually caused by abnormal gene overexpression. Herein, multifunctional nanocomplexes (Que/siBCL2@BioMICs) were developed to deliver quercetin (Que) and BCL-2 siRNA (siBCL2) to synergistically inhibit tumor growth. The nanocomplexes were composed of an amphiphilic triblock copolymer of poly(ethylene glycol) methyl ether methacrylate-poly[2-(dimethylamino) ethyl acrylate]-polycaprolactone (PEGMA-PDMAEA-PCL) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-biotin (DSPE-PEG-biotin). Que was encapsulated into the cores through hydrophobic interactions, while negatively charged siBCL2 was loaded through electrostatic interactions. The nanocomplexes could effectively facilitate cellular uptake via biotin-mediated active targeting and cytosolic release of cargos by the "proton sponge effect" of PDMAEA. Que/siBCL2@BioMICs achieved enhanced cytotoxicity and anti-metastasis activity due to a synergistic effect of Que and siBCL2 in vitro. More importantly, superior anti-tumor efficacy was observed in orthotopic 4T1 tumor-bearing mice with reduced primary tumor burden and lung metastatic nodules, while no obvious side effects to major organs were observed. In conclusion, the biotin-targeted nanocomplexes with chemotherapeutic and nucleotide agent entrapment provide a promising strategy for efficient triple-negative breast cancer (TNBC) therapy.

ROS-responsive Galactosylated-nanoparticles with Doxorubicin Entrapment for Triple Negative Breast Cancer Therapy.

Background: Triple negative breast cancer (TNBC) is one of the most aggressive tumors with high metastasis and mortality, which constitutes 15~20% of all breast cancers. Chemotherapy remains main therapeutic option in the treatment of patients with TNBC. Methods: We developed reactive oxygen species (ROS)-responsive galactosylated nanoparticles (DOX@NPs) as an efficiently targeted carrier for doxorubicin (DOX) delivery to inhibit the growth of TNBC in vitro and in vivo. DOX@NPs were composed of polyacrylate galactose and phenylboronic derivatives conjugation. The in vitro cytotoxicity, cellular uptake, cell apoptosis and cycle distribution of tumor cells treated with different formulations were investigated. Meanwhile in vivo biodistribution and antitumor effects were investigated in a 4T1 tumor-bearing mouse model. Results: DOX@NPs showed good ROS responsiveness and rapid DOX release in the presence of H2O2. Furthermore, our data suggested that DOX@NPs could effectively trigger tumor cells apoptosis and cycle arrest, efficiently accumulate into tumor sites, and suppress tumor growth without adverse side effects. Conclusion: Our results suggested DOX@NP with potent potential as a promising nanocarrier for TNBC therapy, which deserved further investigation for other cancer treatment.

Efficient tumor synergistic chemoimmunotherapy by self-augmented ROS-responsive immunomodulatory polymeric nanodrug.

Immunotherapy has emerged as a promising therapeutic strategy for cancer therapy. However, the therapeutic efficacy has been distracted due to poor immunogenicity and immunosuppressive tumor microenvironment. In this study, a self-augmented reactive oxygen species (ROS) responsive nanocarrier with immunogenic inducer paclitaxel (PTX) and indoleamine 2,3-dixoygenase 1 (IDO1) blocker 1-methyl-D, L-tryptophan (1-MT) co-entrapment was developed for tumor rejection. The carrier was composed of poly (ethylene glycol) (PEG) as hydrophilic segments, enzyme cleavable 1-MT ester and ROS-sensitive peroxalate conjugation as hydrophobic blocks. The copolymer could self-assemble into prodrug-based nanoparticles with PTX, realizing a positive feedback loop of ROS-accelerated PTX release and PTX induced ROS generation. Our nanoparticles presented efficient immunogenic cell death (ICD) which provoked antitumor immune responses with high effector T cells infiltration. Meanwhile immunosuppressive tumor microenvironment was simultaneously modulated with reduced regulatory T cells (Tregs) and M2-tumor associated macrophages (M2-TAMs) infiltration mediated by IDO inhibition. The combination of PTX and 1-MT achieved significant primary tumor regression and reduction of lung metastasis in 4T1 tumor bearing mice. Therefore, the above results demonstrated co-delivery of immunogenic inducer and IDO inhibitor using the ROS amplifying nanoplatform with potent potential for tumor chemoimmunotherapy.

Targeting necroptosis as an alternative strategy in tumor treatment: From drugs to nanoparticles.

Over last decades, most antitumor therapeutic strategies have focused on apoptosis, however, apoptosis resistance and immunological silence usually led to treatment failure. In this sense, triggering other programmed cell death such as necroptosis may achieve a better therapeutic efficacy and has gained widespread attentions in tumor therapy. Studies in this field have identified several types of necroptosis modulators and highlighted the therapeutic potential of necroptotic cell death in cancer. Nanoparticles further provide possibilities to improve therapeutic outcomes as an efficient drug delivery system, facilitating tumor targeting and controlled cargo release. Furthermore, some nanoparticles themselves can trigger/promote programmed necrosis through hyperthermia, ultrasound and autophagy blockage. These investigations have entered necroptosis for consideration as a promising strategy for tumor therapy, though numerous challenges remain and clinical applications are still distant. In this review, we would briefly introduce molecular mechanism and characteristics of necroptosis, and then summarize recent progress of programmed necrosis and their inducers in tumor therapy. Furthermore, the antitumor strategies that take advantages of nanoparticles to induce necroptosis are also discussed.

Polymeric indoximod based prodrug nanoparticles with doxorubicin entrapment for inducing immunogenic cell death and improving the immunotherapy of breast cancer.

Immunotherapy based on host immunity has emerged as a powerful therapeutic strategy for tumor treatment. However, utilizing the immune system against tumors often fails to result in a durable immune response due to insufficient immunogenicity and the immunosuppressive conditions in the tumor microenvironment. Herein, we developed prodrug-based nanoparticles (DOX/IND@NPs) for the codelivery of indoximod (IND), an indoleamine 2,3-dioxygenase (IDO) inhibitor that can block the IDO pathway and generate antitumor immunity, and doxorubicin, a DNA-damaging therapeutic agent that can induce tumor immunogenic cell death (ICD). The nanocarrier was designed for tumor chemoimmunotherapy, synergistically promoting immunogenicity and modulating the immunosuppressive tumor microenvironment (ITME). Our data showed that DOX induced tumor immunogenicity and increased the infiltration of CD8 + T cells into the tumor microenvironment; nevertheless, immunosuppressive immune cell components, such like regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and tumor associated macrophages (TAMs), hindered the antitumor efficacy. The introduction of IND reduced the levels of these protumor immune cells within the tumor microenvironment and further enhanced CD8 + T cell infiltration and the CD8 +/Treg cell ratio. Moreover, significant reductions in vascular endothelial growth factor (VEGF), MMP9, and CD31 (a vascular marker) expression levels were observed after DOX-IND nanoparticle treatment. This resulted in obvious tumor regression in a murine breast cancer model compared to reference formulations, indicating that the codelivery of DOX and IND is a potent potential strategy for breast cancer chemoimmunotherapy.

Targeted delivery of quercetin by biotinylated mixed micelles for non-small cell lung cancer treatment.

Lung cancer is the leading cause of cancer death world-wide and its treatment remains a challenge in clinic, especially for non-small cell lung cancer (NSCLC). Thus, more effective therapeutic strategies are required for NSCLC treatment. Quercetin (Que) as a natural flavonoid compound has gained increasing interests due to its anticancer activity. However, poor water solubility, low bioavailability, short half-life, and weak tumor accumulation hinder in vivo applications and antitumor effects of Que. In this study, we developed Que-loaded mixed micelles (Que-MMICs) assembled from 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-biotin (DSPE-PEG-biotin) and poly(ethylene glycol) methyl ether methacrylate-poly[2-(dimethylamino) ethyl acrylate]-polycaprolactone (PEGMA-PDMAEA-PCL) for NSCLC treatment. The results showed that Que was efficiently encapsulated into the mixed micelles and the encapsulation efficiency (EE) was up to 85.7%. Cellular uptake results showed that biotin conjugation significantly improved 1.2-fold internalization of the carrier compared to that of non-targeted mixed micelles. In vitro results demonstrated that Que-MMICs could improve cytotoxicity (IC50 = 7.83 µg/mL) than Que-MICs (16.15 µg/mL) and free Que (44.22 µg/mL) to A549 cells, which efficiently induced apoptosis and arrested cell cycle. Furthermore, Que-MMICs showed satisfactory tumor targeting capability and antitumor efficacy possibly due to the combination of enhanced permeability and retention (EPR) and active targeting effect. Collectively, Que-MMICs demonstrated high accumulation at tumor site and exhibited superior anticancer activity in NSCLC bearing mice model.

Quercetin nanoformulations: a promising strategy for tumor therapy.

Phytochemicals as dietary constituents are being widely explored for the prevention and treatment of various diseases. Quercetin, a major constituent of various dietary products, has attracted extensive interest due to its anti-proliferative capability, reversal of multidrug resistance, autophagy promotion and tumor microenvironment modulation on different cancer types. Although quercetin has shown potent medical value, its application as an antitumor drug is limited. Problems like poor solubility, bioavailability and stability, short half-life and weak tumor-targeting biodistribution make quercetin an unreliable candidate for cancer therapy. Nanoparticle based platforms have shown a number of advantages in delivering a hydrophobic drug like quercetin to diseased tissues. Quercetin nanoparticles have demonstrated high encapsulation efficiency, stability, sustained release, prolonged circulation time, improved accumulation at tumor sites and therapeutic efficiency. Moreover, a combination of quercetin with other diagnostic or therapeutic agents in one nanocarrier has achieved enhancements in detecting or treating tumors. In this review, we have tried to summarize the pharmacological activities of quercetin with regard to tumor cells and microenvironments in vitro and in vivo. Furthermore, various nanoformulations have been highlighted for quercetin delivery for cancer treatment. These results suggest that quercetin nanoparticles may be a promising antitumor therapeutic agent.

Stimuli-responsive nanoparticles based on poly acrylic derivatives for tumor therapy.

Serve side effects caused by discriminate damage of chemotherapeutic drugs to normal cell and cancer cells remain a main obstacle in clinic. Hence, continuous efforts have been made to find ways to effectively enhance drug delivery and reduce side effects. Recent decades have witnessed impressive progresses in fighting against cancer, with improved understanding of tumor microenvironment and rapid development in nanoscale drug delivery system (DDS). Nanocarriers based on biocompatible materials provide possibilities to improve antitumor efficiency and minimize off-target effects. Among all kinds of biocompatible materials applied in DDS, polymeric acrylic derivatives such as poly(acrylamide), poly(acrylic acid), poly(N-isopropylacrylamide) present inherent biocompatibility and stimuli-responsivity, and relatively easy to be functionalized. Furthermore, nanocarrier based on polymeric acrylic derivatives have demonstrated high drug encapsulation, improved uptake efficiency, prolonged circulation time and satisfactory therapeutic outcome in tumor. In this review, we aim to discuss recent progress in design and development of stimulus-responsive poly acrylic polymer based nanocarriers for tumor targeting drug delivery.

Targeting macrophages using nanoparticles: a potential therapeutic strategy for atherosclerosis.

Atherosclerosis is one of the leading causes of vascular diseases, with high morbidity and mortality worldwide. Macrophages play a critical role in the development and local inflammatory responses of atherosclerosis, contributing to plaque rupture and thrombosis. Considering their central roles, macrophages have gained considerable attention as a therapeutic target to attenuate atherosclerotic progression and stabilize existing plaques. Nanoparticle-based delivery systems further provide possibilities to selectively and effectively deliver therapeutic agents into intraplaque macrophages. Although challenges are numerous and clinical application is still distant, the design and development of macrophage-targeting nanoparticles will generate new knowledge and experiences to improve therapeutic outcomes and minimize toxicity. Hence, the review aims to discuss various strategies for macrophage modulation and the development and evaluation of macrophage targeting nanomedicines for anti-atherosclerosis.

Dual-targeting tumor cells and tumor associated macrophages with lipid coated calcium zoledronate for enhanced lung cancer chemoimmunotherapy.

Lung cancer is the leading cause of cancer death among both men and women, and non-small cell lung cancer (NSCLC) accounts for almost 80% of such death. Tumor associated macrophage (TAMs) are abundant components in NSCLC. TAMs play critical roles in angiogenesis, immune escape and chemoresistance. Here we developed a dual-targeting drug delivery system (CaZOL@BMNPs) of zoledronate, which could bind to both tumor cells with overexpressed biotin receptors and macrophage mannose receptor (MMR) positive TAMs. The biotin- and mannose-modified lipid coated calcium zoledronate nanoparticles were preferentially internalized in both tumor cells and TAMs, and thereby inhibited their survivals. Our studies demonstrated that CaZOl@BMNPs treatment obviously reduced angiogenesis, reprogrammed immunosuppressive tumor microenvironment and eventually restrained tumor progression with negligible systemic toxicity. Collectively, CaZOL@BMNPs could be a promising approach by dual-targeting tumor cells and TAMs for NSCLS chemoimmunotherapy.

Targeted Delivery of Dasatinib to Deplete Tumor-Associated Macrophages by Mannosylated Mixed Micelles for Tumor Immunotherapy.

Tumor-associated macrophages (TAMs) are abundant in tumors and predominately show protumor M2-type fostering tumor progression. Specific depletion of TAMs is conceivably favorable for antitumor therapy. In this study, mannosylated mixed micelles (DAS-MMic) were developed to specifically deliver dasatinib (DAS) to eliminate TAMs for tumor immunotherapy. In vitro and in vivo results showed that DAS-MMic could effectively eradicate TAMs, decrease angiogenesis, reprogram the immunosuppressive tumor microenvironment, and finally suppress tumor progression. These data suggest the potential of direct elimination of TAMs by DAS-MMic for tumor immunotherapy.

Ischemia Reperfusion Injury: Opportunities for Nanoparticles.

Ischemia reperfusion (IR)-induced oxidative stress, accompanied by inflammatory responses, contributes to morbidity and mortality in numerous diseases such as acute coronary syndrome, stroke, organ transplantation, and limb injury. Ischemia results in profound hypoxia and tissue dysfunction, whereas subsequent reperfusion further aggravates ischemic tissue damage through inducing cell death and activating inflammatory responses. In this review, we highlight recent studies of therapeutic strategies against IR injury. Furthermore, nanotechnology offers significant improvements in this area. Hence, we also review recent advances in nanomedicines for IR therapy, suggesting them as potent and promising strategies to improve drug delivery to IR-injured tissues and achieve protective effects.

Targeted Delivery of Zoledronate to Tumor-Associated Macrophages for Cancer Immunotherapy.

Tumor-associated macrophages (TAMs) are recruited from circulatory monocytes by tumor-derived factors, which differentiate into macrophages residing in the tumor microenvironment. TAMs play critical roles in promoting angiogenesis, invasion, metastasis and immune escape, and the direct depletion of TAMs is a promising strategy for tumor immunotherapy. In this study, we developed lipid-coated calcium zoledronate nanoparticles (CaZol@pMNPs) containing conjugated mannose, which were sterically shielded with an extracellular pH-sensitive material. The NPs specifically targeted TAMs and induced their apoptosis in vitro and in vivo. In a S180 tumor-bearing mouse model, CaZol@pMNPs effectively depleted TAMs, markedly decreased angiogenesis, reduced immune suppression, and eventually restrained tumor growth without eliciting systemic effects. The collective data indicate the potential of the direct depletion of TAMs using CaZol@pMNPs for cancer immunotherapy.

Targeted Delivery of miRNA 155 to Tumor Associated Macrophages for Tumor Immunotherapy.

Tumor associated macrophages (TAMs) are important components residing in the tumor microenvironment. They are immunosuppressive and promote tumor progression. Targeting TAMs and reprogramming their phenotype may be a promising strategy that can restore antitumor immune responses. In this study, we developed a microRNA delivery system based on lipid-coated calcium phosphonate nanoparticles (CaP/miR@pMNPs) containing conjugated mannose and sterically shielded with a pH-responsive material. The nanocarrier could respond to the low pH in the tumor microenvironment and expose mannose to promote cellular internalization in TAMs. The carrier could reactivate TAMs and reprogram their functions, reverse the immunosuppressive tumor microenvironment, and inhibit tumor growth in a tumor-bearing mouse model. In summary, redirecting the polarization of TAMs is a potential therapeutic strategy for tumor immunotherapy.

Exosome-based nanocarriers as bio-inspired and versatile vehicles for drug delivery: recent advances and challenges.

Recent decades have witnessed the fast and impressive development of nanocarriers as a drug delivery system. Considering the safety, delivery efficiency and stability of nanocarriers, there are many obstacles in accomplishing successful clinical translation of these nanocarrier-based drug delivery systems. The gap has urged drug delivery scientists to develop innovative nanocarriers with high compatibility, stability and longer circulation time. Exosomes are nanometer-sized, lipid-bilayer-enclosed extracellular vesicles secreted by many types of cells. Exosomes serving as versatile drug vehicles have attracted increasing attention due to their inherent ability of shuttling proteins, lipids and genes among cells and their natural affinity to target cells. Attractive features of exosomes, such as nanoscopic size, low immunogenicity, high biocompatibility, encapsulation of various cargoes and the ability to overcome biological barriers, distinguish them from other nanocarriers. To date, exosome-based nanocarriers delivering small molecule drugs as well as bioactive macromolecules have been developed for the treatment of many prevalent and obstinate diseases including cancer, CNS disorders and some other degenerative diseases. Exosome-based nanocarriers have a huge prospect in overcoming many hindrances encountered in drug and gene delivery. This review highlights the advances as well as challenges of exosome-based nanocarriers as drug vehicles. Special focus has been placed on the advantages of exosomes in delivering various cargoes and in treating obstinate diseases, aiming to offer new insights for exploring exosomes in the field of drug delivery.

Nanoparticles for tumor immunotherapy.

Although most researches and therapies have been focused on the tumor itself, it is becoming clear that immune cells can not only suppress tumor development but support and maintain their malignant type. Promising recent developments in immunology will provide opportunities for tumor-specific immunotherapy, which can orchestrate the patients immune system to target, fight and eradicate cancer cells without destroying healthy cells. However, antitumor immunity driven by self-immune system alone may be therapeutically insufficient. Developments in nanoparticle based drug delivery system can promote immunotherapy and re-educate immunosuppressive tumor microenvironment (TME), which provide promising strategies for cancer therapy. In this review, we will focus on nanoparticle-based immunotherapeutic approaches against cancer, ranging from nanovaccines, artificial antigen presenting cells (aAPCs) to nanoparticles reversing tumor immunosuppressive microenvironment.

Intracellular release of PluronicL64 unimers into MCF-7/ADR cells to overcome multidrug resistance by surface-modified PAMAM.

Multidrug resistance (MDR) has been a major obstacle to tumor chemotherapy. Pluronic unimers have been reported to be promising copolymers to reverse MDR, and the intracellular delivery of Pluronic unimers is a problem worth thinking. To exert the excellent reversal effect of Pluronic unimers, DOX-loaded G4.0 PAMAM was modified with PluronicL64 via cis-aconitic acid as a pH-sensitive linkage (PCPAMAM/DOX), which could release DOX and Pluronic unimers into cytoplasm. The Pluronic-modified PAMAM (PCPAMAM) exhibited favorable biocompatibility and pH-sensitivity. PCPAMAM/DOX showed a nano-scale size and a sustained in vitro release profile. Compared with a control formulation, PCPAMAM/DOX showed a higher reversal effect on MCF-7/ADR cells and enhanced intracellular drug accumulation. The results of P-gp activity, subcellular distribution of PluronicL64, the ATP level and mitochondrial transmembrane potential all illustrated that free Pluronic unimers could be released by PCPAMAM functioning as reversal agents. In conclusion, PCPAMAM could be a promising vehicle to enhance DOX accumulation by overcoming MDR in MCF-7/ADR cells. This work also provided an effective method to deliver Pluronic unimers into MDR cells.

Anti-EphA10 antibody-conjugated pH-sensitive liposomes for specific intracellular delivery of siRNA.

Therapeutic delivery of small interfering RNA (siRNA) is a major challenge that limits its potential clinical application. Here, a pH-sensitive cholesterol-Schiff base-polyethylene glycol (Chol-SIB-PEG)-modified cationic liposome-siRNA complex, conjugated with the recombinant humanized anti-EphA10 antibody (Eph), was developed as an efficient nonviral siRNA delivery system. Chol-SIB-PEG was successfully synthesized and confirmed with FTIR and (1)H-NMR. An Eph-PEG-SIB-Chol-modified liposome-siRNA complex (EPSLR) was prepared and characterized by size, zeta potential, gel retardation, and encapsulation efficiency. Electrophoresis results showed that EPSLR was resistant to heparin replacement and protected siRNA from fetal bovine serum digestion. EPSLR exhibited only minor cytotoxicity in MCF-7/ADR cells. The results of flow cytometry and confocal laser scanning microscopy suggested that EPSLR enhanced siRNA transfection in MCF-7/ADR cells. Intracellular distribution experiment revealed that EPSLR could escape from the endo-lysosomal organelle and release siRNA into cytoplasm at 4 hours posttransfection. Western blot experiment demonstrated that EPSLR was able to significantly reduce the levels of MDR1 protein in MCF-7/ADR cells. The in vivo study of DIR-labeled complexes in mice bearing MCF-7/ADR tumor indicated that EPSLR could reach the tumor site rather than other organs more effectively. All these results demonstrate that EPSLR has much potential for effective siRNA delivery and may facilitate its therapeutic application.