Selenium Nanoparticles Stabilized by ß-Glucan Nanotubes from Black Fungus and Their Effects on the Proliferation, Apoptosis, and Cell Cycle of HepG2 Cells.

Selenium nanoparticles (Se NPs) have significant anticancer effects, but their poor water solubility and dispersibility limit their further applications in biomedical fields. Biomacromolecules have often been used as dispersants or stabilizers in synthesized Se NPs because they can enhance the dispersibility of Se NPs and reduce their side effects. Our previous studies reported a triple-helix ß-glucan (BFP) from the fruiting bodies of black fungus, which showed a good self-assembly ability in constructing hollow nanotubes for loading metal nanoparticles. Therefore, in the present work, BFP nanotubes were designed as carriers to entrap large amounts of Se NPs in order to enhance their stability and anticancer effects. The results showed that Se NPs were successfully synthesized and loaded inside the BFP nanotubes, and the composite (BFP-Se) exhibited high stability and dispersibility due to the covalent Se-O bonds between the Se NPs and the hydroxyl groups on the BFP nanotubes. Moreover, BFP-Se showed significant effects on the proliferation, apoptosis, and cell cycle of HepG2 cells compared to those exhibited by Se NPs. The mechanism was associated with BFP, which acted as a dispersant or stabilizer, resulting in the enhanced cellular uptake of the Se NPs. BFP also activated the death receptor-mediated and mitochondria-mediated apoptotic pathways in HepG2 cells. These results suggest that BFP-Se has potential applications in biomedical fields, especially for the treatment of human liver cancers.

The extraction, structure characterization and hydrogel construction of a water-insoluble ß-glucan from Poria cocos.

Most reported polysaccharides from Poria cocos (PCPs) in traditional Chinese medicine decoctions were water-soluble heteropolysaccharides while the water-insoluble PCPs were scarcely researched due to the poor water-solubility. In this study, a water-insoluble polysaccharide with high yield of 59%, and high purity with a glucan content of 98.8%, was isolated by diluted sodium hydroxide at low temperature and coded as PCPA. The chemical structure of PCPA was identified as a liner ß-glucan with 1, 3-linked glycosidic bond by the fourier infrared spectrum (FT-IR), ion chromatography (ICP), gas chromatography and mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) measurements. Importantly, PCPA was successfully used to construct hydrogels (PCPA-Gs) with good thermal stability, water retention ability and swelling property through simple physical cross-linking, due to the abundance of hydroxyl groups on glucan chains. Moreover, the rheology analysis of PCPA-Gs showed a rapid transition between gel and sol as well as the shear-thinning property. The hydrogel developed in this study holds promise for applications in the food, pharmaceutical, and cosmetic fields.

Enhanced Immunotherapy Based on Combining the Pro-phagocytosis and Anti-phagocytosis Checkpoint Blockade for Tumor Eradication.

Compared to the activation of acquired immunity by the immune checkpoint blockade, the activation of innate immunity via anti-phagocytosis checkpoint blockade could significantly increase the beneficiary population of immunotherapy. However, the activation of innate immunity and the occurrence of phagocytosis are only accomplished when the interaction between pro-phagocytosis signals and anti-phagocytosis signals is realized. Herein, a versatile nanoplatform (DHMR) based on mesoporous silicon nanoparticles (MSNPs) has been constructed. Two drugs, doxorubicin, a chemotherapeutic drug which could initiate tumor cells to release pro-phagocytosis signals, and RRx-001, an immunoadjuvant that could effectively implement the anti-phagocytosis checkpoint blockade, were loaded in MSNPs. Further decoration of hyaluronic acid encapsulation endows DHMR with the function of tumor targeting and long circulation. Ultimately, the DHMR system could efficiently and accurately target tumor tissue, release the drugs in the tumor microenvironment, achieve the activation of innate immunity, and finally dramatically inhibit the growth and metastasis of tumor cells.

Activating Innate Immunity by a STING Signal Amplifier for Local and Systemic Immunotherapy.

The number of patients who benefit from acquired immunotherapy is limited. Stimulator of interferon genes (STING) signal activation is a significant component to enhance innate immunity, which has been used to realize broad-spectrum immunotherapy. Here, M@P@HA nanoparticles, as a STING signal amplifier, are constructed to enhance innate immunotherapy. Briefly, when M@P@HA was targeted into tumor cells, the nanoparticles decomposed with Mn2+ and activated the release of protoporphyrin (PpIX). Under light irradiation, the generated reactive oxygen species disrupt the cellular redox homeostasis to lead cytoplasm leakage of damaged mitochondrial double-stranded (ds) DNA, which is the initiator of the STING signal. Simultaneously, Mn2+ as the immunoregulator could significantly increase the activity of related protein of a STING signal, such as cyclic GMP-AMP synthase (cGAS) and STING, to further amplify the STING signal of tumor cells. Subsequently, the STING signal of tumor-associated macrophages (TAM) is also activated by capturing dsDNA and Mn2+ that escaped from tumor cells, so as to enhance innate immunity. It is found that, by amplifying the STING signal of tumor tissue, M@P@HA could not only activate innate immunity but also cascade to activate CD8+ T cell infiltration even in a tumor with low immunogenicity.

Aptamer-Gold Nanocage Composite for Photoactivated Immunotherapy.

Immune checkpoint blockade (ICB) has been hailed as the hope for conquering cancer as ICB could produce a significant and durable response to tumor cells. However, the high cost and severe side effects of ICB drugs limited their application for further anticancer therapy. Here, we developed a photoactivated immunotherapy nanoplatform (Apt@AuNC). This nanoplatform could target tumor tissues via enhanced penetration retention (EPR) effect and the aptamer (Apt) could be released from Apt@AuNC in tumor sites via illumination. The immune system in the tumor area was then activated after the combination of Apt and PD-1 protein. The heat generated from AuNC was able to continue killing tumor cells. This nanoplatform could not only achieve the precise immunotherapy but also significantly facilitate the anticancer efficacy.

Dual-Targeted Nanoplatform Regulating the Bone Immune Microenvironment Enhances Fracture Healing.

The immune system and skeletal system are closely linked. Macrophages are one of the most important immune cells for bone remodeling, playing a prohealing role mainly through M2 phenotype polarization. Baicalein (5,6,7-trihydroxyflavone, BCL) has been well documented to have a noticeable promotion effect on M2 macrophage polarization. However, due to the limitations in targeted delivery to macrophages and the toxic effect on other organs, BCL has rarely been used in the treatment of bone fractures. In this study, we developed mesoporous silica and Fe3O4 composite-targeted nanoparticles loaded with BCL (BCL@MMSNPs-SS-CD-NW), which could be magnetically delivered to the fracture site. This induced macrophage recruitment in a targeted manner, polarizing them toward the M2 phenotype, which was demonstrated to induce mesenchymal stem cells (MSCs) toward osteoblastic differentiation. The mesoporous silicon nanoparticles (MSNs) were prepared with surface sulfhydrylation and amination modification, and the mesoporous channels were blocked with ß-cyclodextrin. The outer layer of the mesoporous silicon was added with an amantane-modified NW-targeting peptide to obtain the targeted nanosystem. After entering macrophages, BCL could be released from nanoparticles since the disulfide linker could be cleaved by intracellular glutathione (GSH), resulting in the removal of cyclodextrin (CD) gatekeeper, which is a key element in the pro-bone-remodeling functions such as anti-inflammation and induction of M2 macrophage polarization to facilitate osteogenic differentiation. This nanosystem passively accumulated in the fracture site, promoting osteogenic differentiation activities, highlighting a potent therapeutic benefit with high biosafety.

A Versatile Nanoplatform for Broad-Spectrum Immunotherapy by Reversing the Tumor Microenvironment.

Immunotherapy is currently an important adjuvant therapy for malignant tumors besides surgical treatment. However, the heterogeneity and low immunogenicity of the tumor are two main challenges of the immunotherapy. Here, we have constructed a nanoplatform (CP@mRBC-PpIX) to realize reversion of the tumor acidosis and hypoxia through alkali and oxygen generation triggered by tumor acidosis. By targeting tumor universal features other than endogenous biomarkers, it was found that CP@mRBC-PpIX could polarize tumor-associated macrophages to anti-tumor M1 phenotype macrophages to enhance tumor immune response. Furthermore, under regional light irradiation, the reactive oxygen species produced by photosensitizers located in CP@mRBC-PpIX could increase the immunogenicity of tumors, so that tumor changes from an immunosuppressive "cold tumor" to an immunogenic "hot tumor," thereby increasing the infiltration and response of T cells, further amplifying the effect of immunotherapy. This strategy circumvented the problem of tumor heterogeneity to realize a kind of broad-spectrum immunotherapy, which could effectively prevent tumor metastasis and recurrence.

Enzyme-Driven Membrane-Targeted Chimeric Peptide for Enhanced Tumor Photodynamic Immunotherapy.

Here, a protein farnesyltransferase (PFTase)-driven plasma membrane (PM)-targeted chimeric peptide, PpIX-C6-PEG8-KKKKKKSKTKC-OMe (PCPK), was designed for PM-targeted photodynamic therapy (PM-PDT) and enhanced immunotherapy via tumor cell PM damage and fast release of damage-associated molecular patterns (DAMPs). The PM targeting ability of PCPK originates from the cellular K-Ras signaling, which occurs exclusively to drive the corresponding proteins to PM by PFTase. With the conjugation of the photosensitizer protoporphyrin IX (PpIX), PCPK could generate cytotoxic reactive oxygen species to deactivate membrane-associated proteins, initiate lipid peroxidation, and destroy PM with an extremely low concentration (1 µM) under light irradiation. The specific PM damage further induced the fast release of DAMPs (high-mobility group box 1 and ATP), resulting in antitumor immune responses stronger than those of conventional cytoplasm-localized PDT. This immune-stimulating PM-PDT strategy also exhibited the inhibition effect for distant metastatic tumors when combined with programmed cell death receptor 1 blockade therapy.

PLA-PEG Micelles Loaded with a Classic Vasodilator for Oxidative Cataract Prevention.

The only treatment for cataract in clinic is the clouded lens removal combined with artificial lens implantation. In this study, nifedipine (NFP), a classic vasodilator, was loaded in a U.S. FDA-approved polymer PLA-PEG to form NFP-loaded PLA-PEG micelles as a novel eye drop to prevent oxidative cataract formation and progression at the early stage. The NFP-loaded PLA-PEG micelles not only showed satisfactory biocompatibility and bioavailability, but also efficiently improved the anticataract ability through the inhibition of extracellular calcium ions influx. This study may provide a new insight into the development of cataract treatment.

A two-photon excited O2-evolving nanocomposite for efficient photodynamic therapy against hypoxic tumor.

This paper reported on a two-photon excited nanocomposite FCRH to overcome tumor hypoxia for enhanced photodynamic therapy (PDT). Through modified by ruthenium (Ⅱ) complex (Ru(bpy)32+) and hyperbranched conjugated copolymer with poly (ethylene glycol) arms (HOP), the water-splitting mediated O2 generation can be triggered via two-photon irradiation from iron-doped carbon nitride (Fe-C3N4) for the first time. While exposured to two-photon laser, Ru(bpy)32+ was activated to generate singlet oxygen (1O2) and Fe-C3N4 was triggered to split water for oxygen supply in the mean time. Owing to the injection of photoinduced electrons from excited Ru(bpy)32+ to Fe-C3N4, O2 generation by Fe-C3N4 was significantly accelerated. After accumulation of the nanocomposite by enhanced permeability and retention (EPR) effect, FCRH was demonstrated to alleviate the tumorous hypoxia and consequently enhance the antitumor efficacy of PDT. Furthermore, tumor metabolism evaluations explained the capability of the nanocomposite in reducing intratumoral hypoxia. Our results provide a new diagram for ameliorating the hypoxic tumor microenvironment and accelerating 1O2 generation under two-photon excitation, which will find great potential for spatiotemporally controlled tumor treatment in vivo.

PD-1 Blockade for Improving the Antitumor Efficiency of Polymer-Doxorubicin Nanoprodrug.

Chemotherapy is well recognized to induce immune responses during some chemotherapeutic drugs-mediated tumor eradication. Here, a strategy involving blocking programmed cell death protein 1 (PD-1) to enhance the chemotherapeutic effect of a doxorubicin nanoprodrug HA-Psi-DOX is proposed and the synergetic mechanism between them is further studied. The nanoprodrugs are fabricated by conjugating doxorubicin (DOX) to an anionic polymer hyaluronic acid (HA) via a tumor overexpressed matrix metalloproteinase sensitive peptide (CPLGLAGG) for tumor targeting and enzyme-activated drug release. Once accumulated at the tumor site, the nanoprodrug can be activated to release antitumor drug by tumor overexpressed MMP-2. It is found that HA-Psi-DOX nanoparticles can kill tumor cells effectively and initiate an antitumor immune response, leading to the upregulation of interferon-γ. This cytokine promotes the expression of programmed cell death protein-ligand 1 (PD-L1) on tumor cells, which will cause immunosuppression after interacting with PD-1 on the surface of lymphocytes. The results suggest that the therapeutic efficiency of HA-Psi-DOX nanoparticles is significantly improved when combined with checkpoint inhibitors anti-PD-1 antibody (α-PD1) due to the neutralization of immunosuppression by blocking the interaction between PD-L1 and PD-1. This therapeutic system by combining chemotherapy and immunotherapy further increases the link between conventional tumor therapies and immunotherapy.

MnO2 Motor: A Prospective Cancer-Starving Therapy Promoter.

Here, a tumor-targeted MnO2 motor nanosystem (designed as MG/HA) was constructed by the assembly of glucose oxidase (GOD), manganese dioxide (MnO2), and glycoprotein CD44-targeting polymer hyaluronic acid (HA) to elevate cancer-starving therapy efficacy in solid tumor. Upon the specific uptake of MG/HA by CD44 overexpressed cancer cells, GOD catalyzed the oxidation of glucose into gluconic acid and hydrogen peroxide (H2O2) accompanying the consumption of oxygen (O2). Meanwhile, MnO2 would react with H2O2 and acid to generate O2, which is in turn supplied to the glucose-depletion process, running like a loop. As a result, MnO2 is displayed as a motor to promote the rate of glucose depletion that contributed to the starving therapy. In contrast to G/HA, MG/HA could not only achieve effective glucose consumption to depress cancer progression, but also alleviate hypoxia and reduce the expression of Glut1 to inhibit the metabolism for further restraining the tumor aggressiveness and metastasis. The concept of MnO2 motor shows a promising prospect to overcome the restriction of the starving therapy.

Virus-Inspired Nanogenes Free from Man-Made Materials for Host-Specific Transfection and Bio-Aided MR Imaging.

Many viruses have a lipid envelope derived from the host cell membrane that contributes much to the host specificity and the cellular invasion. This study puts forward a virus-inspired technology that allows targeted genetic delivery free from man-made materials. Genetic therapeutics, metal ions, and biologically derived cell membranes are nanointegrated. Vulnerable genetic therapeutics contained in the formed "nanogene" can be well protected from unwanted attacks by blood components and enzymes. The surface envelope composed of cancer cell membrane fragments enables host-specific targeting of the nanogene to the source cancer cells and homologous tumors while effectively inhibiting recognition by macrophages. High transfection efficiency highlights the potential of this technology for practical applications. Another unique merit of this technology arises from the facile combination of special biofunction of metal ions with genetic therapy. Typically, Gd(III)-involved nanogene generates a much higher T1 relaxation rate than the clinically used Gd magnetic resonance imaging agent and harvests the enhanced MRI contrast at tumors. This virus-inspired technology points out a distinctive new avenue for the disease-specific transport of genetic therapeutics and other biomacromolecules.

A self-delivery membrane system for enhanced anti-tumor therapy.

Nowadays, cell membrane targeting therapy has drawn much attention for its high anti-tumor effect by avoiding the cellular barriers. In this study, therapeutic agent conjugated chimeric peptide (Cp) was anchored in cracked cancer cell membranes (CCCM) to construct a self-delivery membrane system (M-Cp), which could relize precise cell membrane targeting therapy. It was found that compared with Cp, M-Cp could target to the cancer cell membrane with longer retention time, which is very crucial for in vivo applications. And the superior cell membrane targeting ability was attributed to the specific proteins (focal adhesion proteins, focal adhesion kinase, RHO family proteins, and integrin) on the CCCM surface. Importantly, the M-Cp could promote tumor-specific immune response, which further enhanced anti-tumor effect when combined with therapeutic agents in M-Cp. What's more, this self-delivery membrane system could be used as a template for cell membrane targeting therapy by changing the therapeutic agents as well as the CCCM, and this strategy would open a new window for various cell membrane targeting therapy.

A Transformable Chimeric Peptide for Cell Encapsulation to Overcome Multidrug Resistance.

Multidrug resistance (MDR) remains one of the biggest obstacles in chemotherapy of tumor mainly due to P-glycoprotein (P-gp)-mediated drug efflux. Here, a transformable chimeric peptide is designed to target and self-assemble on cell membrane for encapsulating cells and overcoming tumor MDR. This chimeric peptide (C16 -K(TPE)-GGGH-GFLGK-PEG8 , denoted as CTGP) with cathepsin B-responsive and cell membrane-targeting abilities can self-assemble into nanomicelles and further encapsulate the therapeutic agent doxorubicin (termed as CTGP@DOX). After the cleavage of the Gly-Phe-Leu-Gly (GFLG) sequence by pericellular overexpressed cathepsin B, CTGP@DOX is dissociated and transformed from spherical nanoparticles to nanofibers due to the hydrophilic-hydrophobic conversion and hydrogen bonding interactions. Thus obtained nanofibers with cell membrane-targeting 16-carbon alkyl chains can adhere firmly to the cell membrane for cell encapsulation and restricting DOX efflux. In comparison to free DOX, 45-time higher drug retention and 49-fold greater anti-MDR ability of CTGP@DOX to drug-resistant MCF-7R cells are achieved. This novel strategy to encapsulate cells and reverse tumor MDR via morphology transformation would open a new avenue towards chemotherapy of tumor.

A cellular/intranuclear dual-targeting nanoplatform based on gold nanostar for accurate tumor photothermal therapy.

In this work, a cellular/intranuclear dual-targeting nanoplatform was designed for tumor photothermal therapy (PTT). As a photo-to-heat nanoheater, a gold nanostar (GNS) was decorated with a nuclear localization sequence (NLS) to form GNS-NLS which possessed nuclear-targeting ability. After that, hyaluronic acid (HA) was coated on the surface of GNS-NLS (GNS-NLS@HA) via electrostatic interaction for tumor cellular recognition and targeting. It was found that by harnessing the recognition of CD44 receptor by HA, GNS-NLS@HA had the ability to target tumor cells accurately, and further be efficaciously internalized into cells with stellate shape. Subsequently, tumor intracellular hyaluronidase (HAase) from the endosome led to the degradation of HA to expose nuclear-targeting nanoheater GNS-NLS, and GNS-NLS was able to enhance PTT efficiency through subcellular nuclear location by a dual-stage near infrared light irradiation strategy. The first stage of light irradiation was of short duration to enhance the subcellular location of the nanoplatform to nuclei, and the second stage of light irradiation was of long duration to achieve admirable photothermal transduction as well as destruction of nuclei. This cellular/intranuclear dual-targeting nanoplatform, GNS-NLS@HA, displayed prominent tumor suppression efficiency both in vitro and in vivo, and inhibited tumor metastasis effectively.

A biomimetic theranostic O2-meter for cancer targeted photodynamic therapy and phosphorescence imaging.

In this report, a biomimetic theranostic oxygen (O2)-meter (cancer cell membrane@Pt(II) porphyrinic-metal organic framework, designated as mPPt) was constructed for cancer targeted and phosphorescence image-guided photodynamic therapy (PDT). mPPt presents high photosensitizers (PSs) loading and evitable self-quenching behaviors for favorable biological O2 sensing and PDT. Besides, endowed by the surface functionalization of cancer cell membrane, the homotypic targeting and immune escape abilities of mPPt could dramatically enhance its cancer targeting ability. Importantly, the O2-dependent phosphorescence responsibility of mPPt could be employed to pre-evaluate the real time O2 level in situ and guide the PDT under light irradiation. A significant anticancer effect is observed after intravenous injection of mPPt and subsequent treatment with PDT with no obvious side effects. As a versatile platform for cell imaging, O2 fluctuation monitoring as well as PDT, this biomimetic O2-meter exhibits great potential for biological analysis and personalized cancer theranostics.

Versatile Supermolecular Inclusion Complex Based on Host-Guest Interaction for Targeted Gene Delivery.

A facile and targeted gene delivery system was prepared by conjugating ß-cyclodextrin modified polyethylenimine (PEI-CD) and adamantyl peptide (AdGRGDS) based on host-guest interaction. With the rational design between PEI-CD and AdGRGDS, the PEI-CD/AdGRGDS gene delivery system showed excellent DNA binding capability and exhibited good ability to compact DNA into uniform spherical nanoparticles. In vitro luciferase assay showed that gene expression transfected by PEI-CD/AdGRGDS was stronger than that by PEI-CD in HeLa cells, whereas gene expression transfected by PEI-CD/AdGRGDS and PEI-CD was similar to each other in COS7 cells. Internalization of complexes was qualitatively studied using a confocal laser scanning microscope (CLSM) and quantitatively analyzed by flow cytometry, respectively, and targeting specificity was also evaluated by CLSM. Results of CLSM and flow cytometry indicated that PEI-CD/AdGRGDS had good targeting specificity to tumor cells with integrin αvß3 overexpression. To further evaluate the targeting specificity and transfection efficiency in vivo, a rat model with murine hepatic carcinoma cell line H22 was used. PEI-CD/AdGRGDS showed stronger gene expression efficiency than PEI-CD via in vivo transfection of pORF-LacZ and pGL-3 plasmids after subcutaneous injection. Interestingly, PEI-CD/AdGRGDS also showed high targeting specificity and transfection distribution to tumor xenograft after tail-vein injection. In vitro and in vivo assays highlighted the importance of GRGDS targeting specificity to tumor cells with integrin αvß3 overexpression and demonstrated that the PEI-CD/AdGRGDS gene delivery system would have great potential for targeted tumor therapy.

Self-Assembly Drug Delivery System Based on Programmable Dendritic Peptide Applied in Multidrug Resistance Tumor Therapy.

In recent decades, diverse drug delivery systems (DDS) constructed by self-assembly of dendritic peptides have shown advantages and improvable potential for cancer treatment. Here, an arginine-enriched dendritic amphiphilic chimeric peptide CRRK(RRCG(Fmoc))2 containing multiple thiol groups is programmed to form drug-loaded nano-micelles by self-assembly. With a rational design, the branched hydrophobic groups (Fmoc) of the peptides provide a strong hydrophobic force to prevent the drug from premature release, and the reduction-sensitive disulfide linkages formed between contiguous peptides can control drug release under reducing stimulation. As expected, specific to multidrug resistance (MDR) tumor cells, the arginine-enriched peptide/drug (PD) nano-micelles show accurate nuclear localization ability to prevent the drug being pumped by P-glycoprotein (P-gp) in vitro, as well as exhibiting satisfactory efficacy for MDR tumor treatment in vivo. This design successfully realizes stimuli-responsive drug release aimed at MDR tumor cells via an ingenious sequence arrangement.

Dual-Stage Light Amplified Photodynamic Therapy against Hypoxic Tumor Based on an O2 Self-Sufficient Nanoplatform.

Tumor hypoxia severely limits the efficacy of traditional photodynamic therapy (PDT). Here, a liposome-based nanoparticle (designated as LipoMB/CaO2 ) with O2 self-sufficient property for dual-stage light-driven PDT is demonstrated to address this problem. Through a short time irradiation, 1 O2 activated by the photosensitizer methylene blue (MB) can induce lipid peroxidation to break the liposome, and enlarge the contact area of CaO2 with H2 O, resulting in accelerated O2 production. Accelerated O2 level further regulates hypoxic tumor microenvironment and in turn improves 1 O2 generation by MB under another long time irradiation. In vitro and in vivo experiments also demonstrate the superior competence of LipoMB/CaO2 to alleviate tumor hypoxia, suppress tumor growth and antitumor metastasis with low side-effect. The O2 self-sufficient LipoMB/CaO2 nanoplatform with dual-stage light manipulation is a successful attempt for PDT against hypoxic tumor.