Antiangiogenic Therapeutic mRNA Delivery Using Lung-Selective Polymeric Nanomedicine for Lung Cancer Treatment.

Therapeutic antibodies that block vascular endothelial growth factor (VEGF) show clinical benefits in treating nonsmall cell lung cancers (NSCLCs) by inhibiting tumor angiogenesis. Nonetheless, the therapeutic effects of systemically administered anti-VEGF antibodies are often hindered in NSCLCs because of their limited distribution in the lungs and their adverse effects on normal tissues. These challenges can be overcome by delivering therapeutic antibodies in their mRNA form to lung endothelial cells, a primary target of VEGF-mediated pulmonary angiogenesis, to suppress the NSCLCs. In this study, we synthesized derivatives of poly(ß-amino esters) (PBAEs) and prepared nanoparticles to encapsulate the synthetic mRNA encoding bevacizumab, an anti-VEGF antibody used in the clinic. Optimization of nanoparticle formulations resulted in a selective lung transfection after intravenous administration. Notably, the optimized PBAE nanoparticles were distributed in lung endothelial cells, resulting in the secretion of bevacizumab. We analyzed the protein corona on the lung- and spleen-targeting nanoparticles using proteomics and found distinctive features potentially contributing to their organ-selectivity. Lastly, bevacizumab mRNA delivered by the lung-targeting PBAE nanoparticles more significantly inhibited tumor proliferation and angiogenesis than recombinant bevacizumab protein in orthotopic NSCLC mouse models, supporting the therapeutic potential of bevacizumab mRNA therapy and its selective delivery through lung-targeting nanoparticles. Our proof-of-principle results highlight the clinical benefits of nanoparticle-mediated mRNA therapy in anticancer antibody treatment in preclinical models.

Pre-mixing of omega-3 fatty acid-containing liposomes enhances the drug release rate and therapeutic efficacy of anticancer drugs loaded in liposomes.

The therapeutic efficacy of anticancer drugs loaded in liposomes composed of rigid phosphatidylcholine (PC) is hindered by the limited release of these drugs at the tumor site, which in turn hampers delivery of the drug to its intracellular target. In an attempt to improve the therapeutic efficacy of liposomal anticancer drugs, we here explored the use of empty liposomes as "trigger" vehicles to induce drug release from drug-loaded liposomes through liposome-liposome interactions. Empty liposomes containing PC in which omega-3 fatty acids comprised both fatty acid strands (Omega-L) showed a triggering effect on drug release from doxorubicin (DOX)-loaded liposomes (Caelyx). The effectiveness of this triggered-release effect was dependent on the Omega-L composition as well as the mixing ratio of Omega-L to Caelyx. Cryo-TEM and differential calorimetry studies revealed that the Omega-L effect was associated with liposome-liposome interactions that led to loosened membrane packing and increased fluidity of Caelyx. In cultured cells, the intracellular/intranuclear DOX uptake and anticancer efficacy of Caelyx was greatly improved by Omega-L pre-mixing. Intravenous injection of rats with Caelyx, premixed with Omega-L, decreased the area under the plasma concentration-time curve from time zero to time infinity and increased clearance without significantly changing the mean residence time or terminal half-life of DOX compared with Caelyx alone. Ex vivo bioimaging showed that DOX fluorescence in tumors, but not in other organs, was significantly increased by Omega-L premixing. In the mouse xenograft model, premixing of Omega-L with Caelyx suppressed tumor growth 2.5-fold compared with Caelyx. Collectively, the data provide preliminary evidence that the Omega-L-triggered drug release that occurs before and after dosing, particularly at tumor site, improved the therapeutic efficacy of Caelyx. The simple approach described here could enhance the therapeutic value of Caelyx and other anticancer drug-loaded liposomes.

Efficacy of White Spot Syndrome Virus Protein VP28-Expressing Chlorella vulgaris as an Oral Vaccine for Shrimp.

The white spot syndrome virus (WSSV) is the causative agent of white spot disease, which kills shrimp within a few days of infection. Although WSSV has a mortality rate of almost 100% and poses a serious threat to the shrimp farming industry, strategies for its prevention and treatment are extremely limited. In this study, we examined the efficacy of VP28, a recombinant WSSV protein expressed in Chlorella vulgaris (C. vulgaris), as an oral shrimp vaccine. When compared with the control group, in which WSSV had a cumulative mortality of 100%, shrimp treated with 5% VP28-expressing C. vulgaris in their feed only had a 20% cumulative mortality rate 12 days after the WSSV challenge. When compared with the nonvaccinated group, the transcription of anti-lipopolysaccharide factor, C-type lectin, and prophenoloxidase genes, which are involved in shrimp defense against WSSV infection, was upregulated 29.6 fold, 15.4 fold, and 11.5 fold, respectively. These findings highlight C. vulgaris as a potential host for industrial shrimp vaccine production.

Shaping the "hot" immunogenic tumor microenvironment by nanoparticles co-delivering oncolytic peptide and TGF-ß1 siRNA for boosting checkpoint blockade therapy.

Induction of potent immune responses toward tumors remains challenging in cancer immunotherapy, in which it only showed benefits in a minority of patients with "hot" tumors, which possess pre-existing effector immune cells within the tumor. In this study, we proposed a nanoparticle-based strategy to fire up the "cold" tumor by upregulating the components associated with T and NK cell recruitment and activation and suppressing TGF-ß1 secretion by tumor cells. Specifically, LTX-315, a first-in-class oncolytic cationic peptide, and TGF-ß1 siRNA were co-entrapped in a polymer-lipid hybrid nanoparticle comprising PLGA, DSPE-mPEG, and DSPE-PEG-conjugated with cRGD peptide (LTX/siR-NPs). The LTX/siR-NPs showed significant inhibition of TGF-ß1 expression, induction of type I interferon release, and triggering immunogenic cell death (ICD) in treated tumor cells, indicated via the increased levels of danger molecules, an in vitro setting. The in vivo data showed that the LTX/siR-NPs could effectively protect the LTX-315 peptide from degradation in serum, which highly accumulated in tumor tissue. Consequently, the LTX/siR-NPs robustly suppressed TGF-ß1 production by tumor cells and created an immunologically active tumor with high infiltration of antitumor effector immune cells. As a result, the combination of LTX/siR-NP treatment with NKG2A checkpoint inhibitor therapy remarkably increased numbers of CD8+NKG2D+ and NK1.1+NKG2D+ within tumor masses, and importantly, inhibited the tumor growth and prolonged survival rate of treated mice. Taken together, this study suggests the potential of the LTX/siR-NPs for inflaming the "cold" tumor for potentiating the efficacy of cancer immunotherapy.

Liposomal co-delivery of toll-like receptors 3 and 7 agonists induce a hot triple-negative breast cancer immune environment.

Triple-negative breast cancer (TNBC) is highly aggressive and has no standard treatment. Although being considered as an alternative to conventional treatments for TNBC, immunotherapy has to deal with many challenges that hinder its efficacy, particularly the poor immunogenic condition of the tumor microenvironment (TME). Herein, we designed a liposomal nanoparticle (LN) platform that delivers simultaneously toll-like receptor 7 (imiquimod, IQ) and toll-like receptor 3 (poly(I:C), IC) agonists to take advantage of the different toll-like receptor (TLR) signaling pathways, which enhances the condition of TME from a "cold" to a "hot" immunogenic state. The optimized IQ/IC-loaded LN (IQ/IC-LN) was effectively internalized by cancer cells, macrophages, and dendritic cells, followed by the release of the delivered drugs and subsequent stimulation of the TLR3 and TLR7 signaling pathways. This stimulation encouraged the secretion of type I interferon (IFN-α, IFN-ß) and CXCLl0, a T-cell and antigen-presenting cells (APCs) recruitment chemokine, from both cancer cells and macrophages and polarized macrophages to the M1 subtype in in vitro studies. Notably, systemic administration of IQ/IC-LN allowed for the high accumulation of drug content in the tumor, followed by the effective uptake by immune cells in the TME. IQ/IC-LN treatment comprehensively enhanced the immunogenic condition in the TME, which robustly inhibited tumor growth in tumor-bearing mice. Furthermore, synergistic antitumor efficacy was obtained when the IQ/IC-LN-induced immunogenic state in TME was combined with anti-PD1 antibody therapy. Thus, our results suggest the potential of combining 2 TLR agonists to reform the TME from a "cold" to a "hot" state, supporting the therapeutic efficacy of immune checkpoint inhibitors.

Methionine consumption by cancer cells drives a progressive upregulation of PD-1 expression in CD4 T cells.

Programmed cell death protein 1 (PD-1), expressed on tumor-infiltrating T cells, is a T cell exhaustion marker. The mechanisms underlying PD-1 upregulation in CD4 T cells remain unknown. Here we develop nutrient-deprived media and a conditional knockout female mouse model to study the mechanism underlying PD-1 upregulation. Reduced methionine increases PD-1 expression on CD4 T cells. The genetic ablation of SLC43A2 in cancer cells restores methionine metabolism in CD4 T cells, increasing the intracellular levels of S-adenosylmethionine and yielding H3K79me2. Reduced H3K79me2 due to methionine deprivation downregulates AMPK, upregulates PD-1 expression and impairs antitumor immunity in CD4 T cells. Methionine supplementation restores H3K79 methylation and AMPK expression, lowering PD-1 levels. AMPK-deficient CD4 T cells exhibit increased endoplasmic reticulum stress and Xbp1s transcript levels. Our results demonstrate that AMPK is a methionine-dependent regulator of the epigenetic control of PD-1 expression in CD4 T cells, a metabolic checkpoint for CD4 T cell exhaustion.

Scalable and Uniform Fabrication of Dexamethasone-Eluting Depot-Engineered Stem Cell Spheroids as a Microtissue Construct to Target Bone Regeneration.

Potentiation of stem cell potency is critical for successful tissue engineering, especially for bone regeneration. Three-dimensional cell culture and bioactive molecule co-delivery with cells have been proposed to achieve this effect. Here, we provide a uniform and scalable fabrication of osteogenic microtissue constructs of mesenchymal stem cell (MSC) spheroids surface-engineered with dexamethasone-releasing polydopamine-coated microparticles (PD-DEXA/MPs) to target bone regeneration. The microparticle conjugation process was rapid and cell-friendly and did not affect the cell viability or key functionalities. The incorporation of DEXA in the conjugated system significantly enhanced the osteogenic differentiation of MSC spheroids, as evidenced by upregulating osteogenic gene expression and intense alkaline phosphatase and alizarin red S staining. In addition, the migration of MSCs from spheroids was tested on a biocompatible macroporous fibrin scaffold (MFS). The result showed that PD-DEXA/MPs were stably anchored on MSCs during cell migration over time. Finally, the implantation of PD-DEXA/MP-conjugated spheroid-loaded MFS into a calvarial defect in a mouse model showed substantial bone regeneration. In conclusion, the uniform fabrication of microtissue constructs containing MSC spheroids with drug depots shows a potential to improve the performance of MSCs in tissue engineering.

Nanomedicine-based commercial formulations: current developments and future prospects.

Background: In recent decades, there has been a considerable increase in the number of nanomedicine-based formulations, and their advantages, including controlled/targeted drug delivery with increased efficacy and reduced toxicity, make them ideal candidates for therapeutic delivery in the treatment of complex and difficult-to-treat diseases, such as cancer. Areas covered: This review focuses on nanomedicine-based formulation development, approved and marketed nanomedicines, and the challenges faced in nanomedicine development as well as their future prospects. Expert opinion: To date, the Food and Drug Administration and the European Medicines Agency have approved several nanomedicines, which are now commercially available. However, several critical challenges, including reproducibility, proper characterization, and biological evaluation, e.g., via assays, are still associated with their use. Therefore, rigorous studies alongside stringent guidelines for effective and safe nanomedicine development and use are still warranted. In this study, we provide an overview of currently available nanomedicine-based formulations. Thus, the findings here reported may serve as a basis for further studies regarding the use of these formulations for therapeutic purposes in near future.

The effectiveness and adsorption mechanism of iron-carbon nanotube composites for removing phosphate from aqueous environments.

This study successfully employed iron-carbon nanotubes (Fe-CNT) to recover phosphate (P) from water. We examined the effects of various iron concentrations denoted by Fe-CNT-1 and Fe-CNT-2 on P removal and compared them with pristine carbon nanotubes (CNTs). The adsorption capacity of Fe-CNTs was much better than pristine CNTs. According to the high adsorption capacity, Fe-CNT-2 sample was very effective for P recovery and exhibits ∼7 times higher P removal efficiency than that of pristine CNTs. The characterization of the as-obtained adsorbent (Fe-CNT-2) and pristine CNTs were performed using X-ray diffraction, Brunauer-Emmett-Teller method, Field emission scanning electron microscope coupled with energy-dispersive spectroscopy detector (FESEM-EDS), X-ray photoelectron spectroscopy and Transmission electron microscopy. Results demonstrated that iron oxide nanoparticles were successfully deposited on the surface of CNT. The adsorption kinetics and isotherm studies for P removal showed pseudo-second-order rate constants (R2 > 0.99) and the Langmuir isotherm (R2 > 0.99) respectively, thus revealing that the nature of adsorption was chemisorption. The estimated Langmuir adsorption capacity of Fe-CNT-2 was 36.5 mgP/g or 112 mg PO4/g at an equilibrium time of 3 h. The ionic strength provided by SO42-, NO3-, and Cl- demonstrated no considerable influence on phosphate adsorption. Moreover, the P adsorbed Fe-CNT-2 was efficiently recovered with different concentrations of desorbing reagents, such as NaOH and NaCO32-. Moreover, the findings of X-ray photoelectron spectroscopy (XPS) analysis demonstrated that OH group played a major role in the P removal by Fe-CNT-2. The findings of this study demonstrate that Fe-CNT-2 had a great deal of application as an effective and stable adsorbent for the P recovery from aquatic environments.

Untargeted metabolomics-assisted comparative cytochrome P450-dependent metabolism of fenbendazole in human and dog liver microsomes.

Fenbendazole (FBZ), a benzimidazole carbamate anthelmintic, has attracted attention for its antitumor activity. This study examined the metabolic characteristics of FBZ in humans compared with those in dogs. The phase I metabolites were identified in liver microsomal incubates using liquid chromatography-mass spectrometry (MS)-based untargeted metabolomics approaches. Seven metabolites of FBZ were identified by principal component analysis and orthogonal partial least square-discriminant analysis based on the global ion variables of the FBZ incubation groups. The chemical structure of the FBZ metabolites was suggested by examining the MS/MS spectrum and isotope distribution pattern. Cytochrome P450 (CYP) 1A1, CYP2D6, and CYP2J2 were the major isozymes responsible for the FBZ metabolism. No differences in the types of metabolites produced by the two species were noted. Multivariate analysis of human and dog incubation groups showed that five metabolites were relatively abundant in humans and the other two were not. In summary, the phase I metabolic profile of FBZ and the comparative metabolism between humans and dogs were examined using an untargeted metabolomics approach. This study suggests a successful investigation of FBZ metabolism in humans for conducting safety assessments regarding drug repositioning.

Nano drug delivery systems for antisense oligonucleotides (ASO) therapeutics.

Cancer, infectious diseases, and metabolic and hereditary genetic disorders are a global health burden affecting millions of people, with contemporary treatments offering limited relief. Antisense technology treats diseases by targeting their causal agents using its ability to alter or inhibit endogenous or malfunctioning genes. Nine antisense oligonucleotide (ASO) drugs that represent four different chemical classes have been approved for the treatment of rare diseases, including nusinersen, the first new oligonucleotide-based drug. Advances in medicinal chemistry, understanding the molecular pathways, and the availability of vast genetic data have resulted in enormous improvements in the therapeutic performance of ASO drugs; however, their susceptibility to degradation in the circulation, rapid renal clearance, and immunostimulatory adverse effects greatly limit their clinical applications. An increasing number of ASO-based therapeutics is being tested in clinical trials. Improvements to the delivery of ASO drugs could potentially change the therapeutic landscape for many conditions in the near future. This review describes the technological advances and developments in drug delivery systems pertaining to ASO therapeutics.

Modified Aerotaxy for the Plug-in Manufacture of Cell-Penetrating Fenton Nanoagents for Reinforcing Chemodynamic Cancer Therapy.

The assemblies of anisotropic nanomaterials have attracted considerable interest in advanced tumor therapeutics because of the extended surfaces for loading of active molecules and the extraordinary responses to external stimuli for combinatorial therapies. These nanomaterials were usually constructed through templated or seed-mediated hydrothermal reactions, but the lack of uniformity in size and morphology, as well as the process complexities from multiple separation and purification steps, impede their practical use in cancer nanotherapy. Gas-phase epitaxy, also called aerotaxy (AT), has been introduced as an innovative method for the continuous assembly of anisotropic nanomaterials with a uniform distribution. This process does not require expensive crystal substrates and high vacuum conditions. Nevertheless, AT has been used limitedly to build high-aspect-ratio semiconductor nanomaterials. With these considerations, a modified AT was designed for the continuous in-flight assembly of the cell-penetrating Fenton nanoagents (Mn-Fe CaCO3 (AT) and Mn-Fe SiO2 (AT)) in a single-pass gas flow because cellular internalization activity is essential for cancer nanotherapeutics. The modified AT of Mn-Fe CaCO3 and Mn-Fe SiO2 to generate surface nanoroughness significantly enhanced the cellular internalization capability because of the preferential contact mode with the cancer cell membrane for Fenton reaction-induced apoptosis. In addition, it was even workable for doxorubicin (DOX)-resistant cancer cells after DOX loading on the nanoagents. After combining with immune-checkpoint blockers (antiprogrammed death-ligand 1 antibodies), the antitumor effect was improved further with no systemic toxicity as chemo-immuno-chemodynamic combination therapeutics despite the absence of targeting ligands and external stimuli.

Engineering of hybrid spheroids of mesenchymal stem cells and drug depots for immunomodulating effect in islet xenotransplantation.

Immunomodulation is an essential consideration for cell replacement procedures. Unfortunately, lifelong exposure to nonspecific systemic immunosuppression results in immunodeficiency and has toxic effects on nonimmune cells. Here, we engineered hybrid spheroids of mesenchymal stem cells (MSCs) with rapamycin-releasing poly(lactic-co-glycolic acid) microparticles (RAP-MPs) to prevent immune rejection of islet xenografts in diabetic C57BL/6 mice. Hybrid spheroids were rapidly formed by incubating cell-particle mixture in methylcellulose solution while maintaining high cell viability. RAP-MPs were uniformly distributed in hybrid spheroids and sustainably released RAP for ~3 weeks. Locoregional transplantation of hybrid spheroids containing low doses of RAP-MPs (200- to 4000-ng RAP per recipient) significantly prolonged islet survival times and promoted the generation of regional regulatory T cells. Enhanced programmed death-ligand 1 expression by MSCs was found to be responsible for the immunomodulatory performance of hybrid spheroids. Our results suggest that these hybrid spheroids offer a promising platform for the efficient use of MSCs in the transplantation field.

Recent advancements in lipid-mRNA nanoparticles as a treatment option for cancer immunotherapy.

Background: Cancer remains a serious health concern worldwide, and different approaches are being developed for its treatment. The strategy to use the immune system as an approach for treating cancer has recently gained momentum. Messenger RNA (mRNA) has been assessed as an up-and-coming resource for the evolution of advanced cancer immunotherapies over the past decades. However, degradation in extracellular compartments and during endosomal escape remain obstacles for efficient mRNA delivery and limit the therapeutic applications of this approach. Area covered: Lipid-based nanocarriers are gaining significant attention as non-viral mRNA vectors. Various lipid-based nanocarrier types have been developed to enhance the stability of mRNA molecules, facilitate their transfection, and ensure delivery to an intracellular compartment suitable for further processing. This review discusses the development of novel mRNA delivery systems using lipids for effective cancer immunotherapy. Expert opinion: mRNAs are superior to other biomolecules for developing therapeutic drugs and vaccines with multiple medical applications that are currently being explored by researchers in various biomedical fields. Lipid-based mRNA nanoparticles can improve the potency of the mRNA by enhancing its stability, enabling its cellular uptake, and facilitating its endosomal escape. Targetability of these therapeutics can be increased by conjugating their surface with the desired ligands or targeting agents. Lipid-mRNA nanoparticles are increasingly being incorporated in cancer immunotherapy applications, including vaccines, monoclonal antibodies, and chimeric antigen receptor T-cell treatment, and several such nanoparticles are being assessed in clinical trials. Further research that assesses key variables for transfection efficiency of lipid-mRNA nanoparticles will expedite the development of improved therapeutics.

Streamlined plug-in aerosol prototype for reconfigurable manufacture of nano-drug delivery systems.

The significant advances in nano-drug delivery systems (NDDS) for anticancer agents have led to the development of computational techniques, such as machine learning and neural networks to identify the optimal architectural and compositional design in a wide variety of therapeutic nanoformulations. On the other hand, few studies have examined downsized plug-in reaction-ware embodied in an autonomous platform for the instant reconfigurable production of engineered nanomaterials to guide optimal NDDS designs and delivery strategies. This paper describes an on-demand system for an electrically operable, continuously processible material produced by sequential spray pyrolysis and vibrating spray for single-pass NDDS assembly. In particular, a mild chemotherapeutic NDDS consisting of amorphous boron nitride (a-BN; a stable base material for loading), doxorubicin (DOX; an anticancer drug), and folic acid-chitosan conjugate (FACHI; a targeting and antiopsonic agent), called a-BN-DOX@FACHI, was fabricated using the developed system. a-BN-DOX@FACHI was assessed for the pH-responsive release of DOX, targeting of the folate receptor, and its resistance to opsonization and macrophage phagocytosis. a-BN-DOX@FACHI was found to be a mild cancer chemotherapeutic with reasonable biosafety. Integrating a metal ablation device with the developed on-demand system enabled the reconfiguration of NDDS from a-BN-DOX@FACHI to a-BN-Au-DOX@FACHI or a-BN-Pt-cisplatin@bovine serum albumin to add a photothermal effect with a range of architectures and compositions.

Field study on short-term changes in benthic environment and benthic microbial communities using pyrolyzed oyster shells.

To evaluate the effect of pyrolyzed crushed oyster shells (PCOS) on the remediation of sediments and microbial diversity, a field study was conducted in Buksin Bay, Tongyeong City, Republic of Korea. It was observed that after treatment with PCOS, the concentration of H2S in the sediment of the control site was 287 mg/L. Furthermore, it decreased up to 0 mg/L and remained so until the end of the field study, that is for a period of six months. Moreover, the concentrations of NO2-N + NO3-N, NH4-N, and PO4-P decreased sharply, and the oxidation-reduction potential (ORP) increased after PCOS treatment in pore water and overlying water. Regarding the diversity of microbial communities, the predominance of bacteria from phylum Chlorobi was observed in highly reduced (-410 mV; ORP) sediment, which is well known for the production of H2S. After PCOS treatment, the relative abundance of Chlorobi was sharply suppressed. On the other hand, the predominance of bacteria from the phyla Proteobacteria and Bacteroidetes was observed, and their relative abundance in the PCOS-treated sediment increased throughout the experiment, based on 16S rRNA sequencing. The results demonstrate that the abundance of bacterial communities in the PCOS-treated sediments of Buksin Bay is important for marine ecological functioning, especially for pollutant transformation.

AMPK promotes antitumor immunity by downregulating PD-1 in regulatory T cells via the HMGCR/p38 signaling pathway.

BACKGROUND: AMP-activated protein kinase (AMPK) is a metabolic sensor that maintains energy homeostasis. AMPK functions as a tumor suppressor in different cancers; however, its role in regulating antitumor immunity, particularly the function of regulatory T cells (Tregs), is poorly defined. METHODS: AMPKα1fl/flFoxp3YFP-Cre, Foxp3YFP-Cre, Rag1-/-, and C57BL/6 J mice were used for our research. Flow cytometry and cell sorting, western blotting, immuno-precipitation, immuno-fluorescence, glycolysis assay, and qRT-PCR were used to investigate the role of AMPK in suppressing programmed cell death 1 (PD-1) expression and for mechanistic investigation. RESULTS: The deletion of the AMPKα1 subunit in Tregs accelerates tumor growth by increasing the expression of PD-1. Metabolically, loss of AMPK in Tregs promotes glycolysis and the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), a key enzyme of the mevalonate pathway. Mechanistically, AMPK activates the p38 mitogen-activated protein kinase (MAPK) that phosphorylates glycogen synthase kinase-3ß (GSK-3ß), inhibiting the expression of PD-1 in Tregs. CONCLUSION: Our study identified an AMPK regulatory mechanism of PD-1 expression via the HMGCR/p38 MAPK/GSK3ß signaling pathway. We propose that the AMPK activator can display synergic antitumor effect in murine tumor models, supporting their potential clinical use when combined with anti-PD-1 antibody, anti-CTLA-4 antibody, or a HMGCR inhibitor.

Preparation and evaluation of dabrafenib-loaded, CD47-conjugated human serum albumin-based nanoconstructs for chemoimmunomodulation.

The transmembrane proteins, CD47 and signal-regulatory protein α are overexpressed in cancer cells and macrophages, respectively, and facilitate the escape of cancer cells from macrophage-mediated phagocytosis. The immunomodulatory and targeting properties of CD47, the chemotherapeutic effects of dabrafenib (D), and the anti-programmed death-1 antibodies (PD-1) pave the way for effective chemoimmunomodulation-mediated anticancer combination therapy. In this study, CD47-conjugated, D-loaded human serum albumin (HSA) nanosystems were fabricated by modified nanoparticle albumin-bound technology. Cis-aconityl-PEG-maleimide (CA), an acid-labile linker, was used to conjugate D@HSA and CD47; the resultant CD47-CA@D@HSA exhibited tumor-specificity through receptor targeting, as well as preferential cleavage and drug release in the acidic tumor microenvironment (pH 5) compared to normal physiological pH conditions (pH 6.5, 7.4). The successful preparation of nanosized (∼220 nm), narrowly dispersed (∼0.13) CD47-CA@D@HSA was proven by physicochemical characterization. In vitro and in vivo internalization, accumulation, cytotoxicity, and apoptosis were observed to be higher with CD47-conjugated nanoconstructs, than with free D or non-targeted nanoconstructs. CD47-CA@D@HSA was found to promote the infiltration of cytotoxic T cells and tumor-associated macrophages into tumors and improve in vivo tumor inhibition. Administration in combination with PD-1 further improved antitumor efficacy by promoting immune responses that blocked the immune checkpoint. No signs of toxicity were seen in mice treated with the nanoconstructs; the formulation was, therefore, thought to be biocompatible and as having potential for clinical use. The targeted chemoimmunomodulation achieved by this combination therapy was found to combat major immunosuppressive facets, making it a viable candidate for use in the treatment of cancer.

Nanovaccines silencing IL-10 production at priming phase for boosting immune responses to melanoma.

Despite the significant efforts in developing cancer vaccines, there are still numerous challenges that need to be addressed to ensure their clinical efficacy. Herein, a lymphatic dendritic cell (DC)-targeted artificial nanovaccine mimicking tumor cell membrane (ATM-NV) is developed to boost effector immune response and control immunosuppression simultaneously. The NVs are formulated with lipids, tumor cell membrane proteins, imiquimod (IMQ), and IL-10 siRNA. IL-10 siRNA is incorporated to inhibit the secretion of IL-10, an immunosuppressive cytokine, of maturated DCs upon IMQ. To enhance the DC targeting ability, the nanovaccine surface was non-covalently conjugated with the anti-CD205 antibody. The IMQ and IL-10 siRNA co-loaded, CD205 receptor-targeted artificial tumor membrane NVs (IMQ/siR@ATM-NVs) efficiently migrate to the tumor-draining lymph node and target DCs. Furthermore, immunization with IMQ/siR@ATM-NVs reduces the production of IL-10 and increases Th1-driven antitumor immunity resulted in a great tumor inhibition efficacy. Our results suggest a potential strategy to promote the vaccination's antitumor efficacy by blocking the intrinsic negative regulators in DCs.

Recent progress in stimuli-responsive nanosystems for inducing immunogenic cell death.

Low immunogenicity and immunosuppressive tumor microenvironments are major hurdles in the application of cancer immunotherapy. To date, several immunogenic cell death (ICD) inducers have been reported to boost cancer immunotherapy by triggering ICD. ICD is characterized by the release of proinflammatory cytokines, danger-associated molecular patterns (DAMPs) and tumor associated antigens which will generate anticancer immunity by triggering adaptive immune cells. However, application of ICD inducers is limited due to severe toxicity issues and inefficient localization in the tumor microenvironment. To circumvent these challenges, stimuli-responsive nanoparticles have been exploited for improving cancer immunotherapy by limiting its toxicity. The combination of stimuli-responsive nanoparticles with an ICD inducer serves as a promising strategy for increasing the clinical applications of ICD induction in cancer immunotherapy. Here, we outline recent advances in ICD mediated by stimuli-responsive nanoparticles that may be near-infrared (NIR)-responsive, pH-responsive, redox responsive, pH and enzyme responsive, or pH and redox responsive, and evaluate their significant potential for successful clinical translation in cancer immunotherapy.