FNIII14 Peptide-Enriched Membrane Nanocarrier to Disrupt Stromal Barriers through Reversing CAFs for Augmenting Drug Penetration in Tumors.

Given the key roles of cancer associated fibroblasts (CAFs) in shaping tumor stroma, this study shows a CAF-associated ITGB1-inactivating peptide-enriched membrane nanodelivery system (designated as PMNPs-D) to simultaneously target CAFs and tumor cells for boosted chemotherapy through promoted drug perfusion. In the structure of PMNPs-D, the PLGA-based inner core is loaded with the chemotherapeutic drug doxorubicin, and the outer surface is cloaked by hybrid biomembranes with the insertion of integrin ß1 (ITGB1) inhibiting peptide (i.e., FNIII14). After prolonged blood circulation and actively targeting in tumor sites, PMNPs-D can respond to CAF-overexpressed fibroblast activation protein-α (FAP-α) to trigger the release of FNIII14, which will bind to ITGB1 and inhibit CAFs' biological function in producing the stromal matrix, thereby loosening the condensed stromal structure and enhancing the permeability of nanotherapeutics in tumors. As a result, this tailor-designed nanosystem shows substantial tumor inhibition and metastasis retardation in aggressive adenoid cystic carcinoma (ACC) tumor-harboring mice.

Immunostimulant Hydrogel-Guided Tumor Microenvironment Reprogramming to Efficiently Potentiate Macrophage-Mediated Cellular Phagocytosis for Systemic Cancer Immunotherapy.

Macrophage-mediated cellular phagocytosis (MMCP) plays a critical role in conducting antitumor immunotherapy but is usually impaired by the intrinsic phagocytosis evading ability of tumor cells and the immunosuppressive tumor microenvironment (TME). Herein, a MMCP-boosting hydrogel (TCCaGM) was elaborately engineered by encapsulating granulocyte-macrophage colony-stimulating factor (GM-CSF) and a therapeutic nanoplatform (TCCaN) that preloaded with the tunicamycin (Tuni) and catalase (CAT) with the assistance of CaCO3 nanoparticles (NPs). Strikingly, the hypoxic/acidic TME was efficiently alleviated by the engineered hydrogel, "eat me" signal calreticulin (CRT) was upregulated, while the "don't eat me" signal CD47 was downregulated on tumor cells, and the infiltrated DCs were recruited and activated, all of which contributed to boosting the macrophage-mediated phagocytosis and initiating tumor-specific CD8+ T cells responses. Meanwhile, the remodeled TME was beneficial to accelerate the polarization of tumor-associated macrophages (TAMs) to the antitumoral M1-like phenotype, further heightening tumoricidal immunity. With the combination of PD-1 antibody (αPD-1), the designed hydrogel significantly heightened systemic antitumor immune responses and long-term immunological effects to control the development of primary and distant tumors as well as suppress tumor metastasis and recurrence, which established an optimal strategy for high-performance antitumor immunotherapy.

Interference of Glucose Bioavailability of Tumor by Engineered Biohybrids for Potentiating Targeting and Uptake of Antitumor Nanodrugs.

The chemotherapy efficacy of nanodrugs is restricted by poor tumor targeting and uptake. Here, an engineered biohybrid living material (designated as EcN@HPB) is constructed by integrating paclitaxel and BAY-876 bound human serum albumin nanodrugs (HPB) with Escherichia coli Nissle 1917 (EcN). Due to the inherent tumor tropism of EcN, EcN@HPB could actively target the tumor site and competitively deprive glucose through bacterial respiration. Thus, albumin would be used as an alternative nutrient source for tumor metabolism, which significantly promotes the internalization of HPB by tumor cells. Subsequently, BAY-876 internalized along with HPB nanodrugs would further depress glucose uptake of tumor cells via inhibiting glucose transporter 1 (GLUT1). Together, the decline of glucose bioavailability of tumor cells would activate and promote the macropinocytosis in an AMP-activated protein kinase (AMPK)-dependent manner, resulting in more uptake of HPB by tumor cells and boosting the therapeutic outcome of paclitaxel.

A Self-Driven Bioreactor Based on Bacterium-Metal-Organic Framework Biohybrids for Boosting Chemotherapy via Cyclic Lactate Catabolism.

The excessive lactate in the tumor microenvironment always leads to poor therapeutic outcomes of chemotherapy. In this study, a self-driven bioreactor (defined as SO@MDH, where SO is Shewanella oneidensis MR-1 and MDH is MIL-101 metal-organic framework nanoparticles/doxorubicin/hyaluronic acid) is rationally constructed via the integration of doxorubicin (DOX)-loaded metal-organic framework (MOF) MIL-101 nanoparticles with SO to sensitize chemotherapy. Owing to the intrinsic tumor tropism and electron-driven respiration of SO, the biohybrid SO@MDH could actively target and colonize hypoxic and eutrophic tumor regions and anaerobically metabolize lactate accompanied by the transfer of electrons to Fe3+, which is the key component of the MIL-101 nanoparticles. As a result, the intratumoral lactate would undergo continuous catabolism coupled with the reduction of Fe3+ to Fe2+ and the subsequent degradation of MIL-101 frameworks, leading to an expeditious drug release for effective chemotherapy. Meanwhile, the generated Fe2+ will be promptly oxidized by the abundant hydrogen peroxide in the tumor microenvironment to reproduce Fe3+, which is, in turn, beneficial to circularly catabolize lactate and boost chemotherapy. More importantly, the consumption of intratumoral lactic acid could significantly inhibit the expression of multidrug resistance-related ABCB1 protein (also named P-glycoprotein (P-gp)) for conquering drug-resistant tumors. SO@MDH demonstrated here holds high tumor specificity and promising chemotherapeutic efficacy for suppressing tumor growth and overcoming multidrug resistance, confirming its potential prospects in cancer therapy.

A tumor-cell biomimetic nanoplatform embedding biological enzymes for enhanced metabolic therapy.

A tumor cell membrane-camouflaged therapeutic system was fabricated to eliminate tumors by embedding apyrase and glucose oxidase (GOx) into zeolitic imidazolate framework-8 (ZIF-8) nanoparticles for tumor-targeted metabolic therapy. Experimental results demonstrated that these functional nanoparticles could disturb the energy supply of tumor cells by depleting ATP and glucose and efficiently induce tumor cell death.

Recent Advances in Engineered Materials for Immunotherapy-Involved Combination Cancer Therapy.

Immunotherapy that can activate immunity or enhance the immunogenicity of tumors has emerged as one of the most effective methods for cancer therapy. Nevertheless, single-mode immunotherapy is still confronted with several critical challenges, such as the low immune response, the low tumor infiltration, and the complex immunosuppression tumor microenvironment. Recently, the combination of immunotherapy with other therapeutic modalities has emerged as a powerful strategy to augment the therapeutic outcome in fighting against cancer. In this review, recent research advances of the combination of immunotherapy with chemotherapy, phototherapy, radiotherapy, sonodynamic therapy, metabolic therapy, and microwave thermotherapy are summarized. Critical challenges and future research direction of immunotherapy-based cancer therapeutic strategy are also discussed.

Cell primitive-based biomimetic functional materials for enhanced cancer therapy.

Cell primitive-based functional materials that combine the advantages of natural substances and nanotechnology have emerged as attractive therapeutic agents for cancer therapy. Cell primitives are characterized by distinctive biological functions, such as long-term circulation, tumor specific targeting, immune modulation etc. Moreover, synthetic nanomaterials featuring unique physical/chemical properties have been widely used as effective drug delivery vehicles or anticancer agents to treat cancer. The combination of these two kinds of materials will catalyze the generation of innovative biomaterials with multiple functions, high biocompatibility and negligible immunogenicity for precise cancer therapy. In this review, we summarize the most recent advances in the development of cell primitive-based functional materials for cancer therapy. Different cell primitives, including bacteria, phages, cells, cell membranes, and other bioactive substances are introduced with their unique bioactive functions, and strategies in combining with synthetic materials, especially nanoparticulate systems, for the construction of function-enhanced biomaterials are also summarized. Furthermore, foreseeable challenges and future perspectives are also included for the future research direction in this field.

Constitutional Dynamic Networks-Guided Synthesis of Programmed "Genes", Transcription of mRNAs, and Translation of Proteins.

Inspired by nature, where dynamic networks control the levels of gene expression and the activities of transcribed/translated proteins, we introduce nucleic acid-based constitutional dynamic networks (CDNs) as functional modules mimicking native circuits by demonstrating CDNs-guided programmed synthesis of genes, controlled transcription of RNAs, and dictated transcription/translation synthesis of proteins. An auxiliary CDN consisting of four dynamically equilibrated constituents AA', AB', BA', and BB' is orthogonally triggered by two different inputs yielding two different compositionally reconfigured CDNs. Subjecting the parent auxiliary CDN to two hairpins, HA and HB, and two templates TA and TB and a nicking/replication machinery leads to the cleavage of the hairpins and to the activation of the nicking/replication machineries that synthesize two "genes", e.g., the histidine-dependent DNAzyme g1 and the Zn2+-ion-dependent DNAzyme g2. The triggered orthogonal reconfiguration of the parent CDN to the respective CDNs leads to the programmed preferred CDN-guided synthesis of g1 or g2. Similarly, the triggered reconfigured CDNs are subjected to two hairpins HC and HD, the templates I'/I and J'/J, and the RNA polymerase (RNAp)/NTPs machinery. While the cleavage of the hairpins by the constituents associated with the parent CDN leads to the transcription of the broccoli aptamer recognizing the DFHBI ligand and of the aptamer recognizing the malachite green (MG) ligand, the orthogonally triggered CDNs lead to the CDNs-guided enhanced transcription of either the DFHBI aptamer or the MG aptamer. In addition, subjecting the triggered reconfigured CDNs to predesigned hairpins HE and HF, the templates M'/M and N'/N, the RNAp/NTPs machinery, and the cell-free ribosome t-RNA machinery leads to the CDNs-guided transcription/translation of the green fluorescence protein (GFP) or red fluorescence protein (RFP).

Modelling Photosynthesis with ZnII -Protoporphyrin All-DNA G-Quadruplex/Aptamer Scaffolds.

All-DNA scaffolds act as templates for the organization of photosystem I model systems. A series of DNA templates composed of ZnII -protoporphyrin IX (ZnII PPIX)-functionalized G-quadruplex conjugated to the 3'- or 5'-end of the tyrosinamide (TA) aptamer and ZnII PPIX/G-quadruplex linked to the 3'- and 5'-ends of the TA aptamer through a four-thymidine bridge. Effective photoinduced electron transfer (ET) from ZnII PPIX/G-quadruplex to bipyridinium-functionalized tyrosinamide, TA-MV2+ , bound to the TA aptamer units is demonstrated. The effectiveness of the primary ET quenching of ZnII PPIX/G-quadruplex by TA-MV2+ controls the efficiency of the generation of TA-MV+. . The photosystem-controlled formation of TA-MV+. by the different photosystems dictates the secondary activation of the ET cascade corresponding to the ferredoxin-NADP+ reductase (FNR)-catalysed reduction of NADP+ to NADPH by TA-MV+. , and the sequestered alcohol dehydrogenase catalysed reduction of acetophenone to 1-phenylethanol by NADPH.

100th Anniversary of Macromolecular Science Viewpoint: Poly(N-isopropylacrylamide)-Based Thermally Responsive Micelles.

Poly(N-isopropylacrylamide) (PNIPAAm)-based thermally responsive micelles are of great importance as smart materials for a number of applications such as drug delivery and biosensing, owing to their tunable lower critical solution temperature (LCST). Their design and synthesis in the nanoscale size range have been widely studied, and research interest in their structural and physic-chemical properties is continually growing. In this Viewpoint, representative research on the construction of PNIPAAm-based thermally responsive micelles as well as their applications are highlighted and discussed, which would serve as a good start for newcomers in this field and a positive guide for future research.

Photosensitized H2 Evolution and NADPH Formation by Photosensitizer/Carbon Nitride Hybrid Nanoparticles.

The broadband C3N4 semiconductor absorbs in the UV region, λ = 330-380 nm, a feature limiting its application for light-to-energy conversion. The unique surface adsorption properties of C3N4 allow, however, the binding of a photosensitizer, operating in the visible-solar spectrum to the surface of C3N4. Coupling of the energy levels of the photosensitizer with the energy levels of C3N4 allows effective photoinduced electron-transfer quenching and subsequent charge separation in the hybrid structures. Two methods to adsorb a photosensitizer on the C3N4 nanoparticles are described. One is exemplified by the adsorption of Zn(II)-protoporphyrin IX on C3N4 using π-π interactions. The second method utilizes the specific binding interactions of single-stranded nucleic acids on C3N4 and involves the binding of a Ru(II)-tris-bipyridine-modified nucleic acid on the C3N4 nanoparticles. Effective electron-transfer quenching of the photoexcited photosensitizers by C3N4 proceeds in the two hybrid systems. The two hybrid photosystems induce the effective photosensitized reduction of N,N'-dimethyl-4,4'-bipyridinium, MV2+, to MV+•, in the presence of Na2EDTA as a sacrificial electron donor. The generation of MV+• is ca. 5-fold higher as compared to the formation of MV+• in the presence of the photosensitizer alone (in the absence of C3N4). The effective generation of MV+• in the photosystems is attributed to the efficient quenching of the photosensitizers, followed by effective charge separation of the electrons in the conduction band of C3N4 and the holes in the oxidized photosensitizer. The subsequent transfer of the conduction-band electrons to MV2+ and the oxidation of Na2EDTA by the oxidized photosensitizers lead to the effective formation of MV+•. The photogenerated MV+• by the two hybrid photosystems is used to catalyze H2 evolution in the presence of Pt nanoparticle catalysts and to mediate the reduction of NADP+ to NADPH, in the presence of ferredoxin-NADP+ reductase, FNR. The ability to couple the photogenerated NADPH to drive NADP+-dependent biocatalytic transformations is demonstrated.

Redox-Switchable Binding Properties of the ATP-Aptamer.

In this study, we report on a redox-controllable and reversible complete "ON"/"OFF"-switchable aptamer binding to ATP. A series of methylene blue-modified ATP-aptamers was synthesized, revealing improved binding affinities toward ATP as compared to the nonmodified aptamer. These binding affinities were dependent on the conjugation site of the redox label on the aptamer scaffold. Importantly, we find that the oxidized methylene blue-modified aptamers bind to ATP with micromolar affinity, while the reduced form lacks binding affinity toward ATP, resulting in an unprecedented complete "ON"/"OFF" redox-controllable aptamer switch. We demonstrate the cyclic "ON"/"OFF" binding of ATP to the methylene blue-functionalized aptamer through cyclic oxidation and reduction of the redox label using both chemical and electrochemical means. Molecular dynamics and docking simulations were performed to account for the redox-switchable properties of the conjugated aptamers and to rationalize the enhanced binding affinities of the different aptamer designs.

Artificial Photosynthesis with Electron Acceptor/Photosensitizer-Aptamer Conjugates.

Sequence-specific aptamers act as functional scaffolds for the assembly of photosynthetic model systems. The Ru(II)-tris-bipyridine photosensitizer is conjugated by different binding modes to the antityrosinamide aptamer to yield a set of photosensitizer-aptamer binding scaffolds. The N-methyl-N'-(3-aminopropane)-4,4'-bipyridinium electron acceptor, MV2+, is covalently linked to tyrosinamide, TA, to yield the conjugate TA-MV2+. The tyrosinamide unit in TA-MV2+ acts as a ligand for anchoring TA-MV2+ to the Ru(II)-tris-bipyridine-aptamer scaffold, generating the diversity of photosensitizer-aptamer/electron acceptor supramolecular conjugates. Effective electron transfer quenching in the photosynthetic model systems is demonstrated, and the quenching efficiencies are controlled by the structural features of the conjugates. The redox species generated by the photosensitizer-aptamer/electron acceptor supramolecular systems mediate the ferredoxin-NADP+ reductase, FNR, catalyzed synthesis of NADPH, and the Pt-nanoparticle-catalyzed evolution of hydrogen (H2). The novelty of the study rests on the unprecedented use of aptamer scaffolds as functional units for organizing photosynthetic model systems.

miRNA-Specific Unlocking of Drug-Loaded Metal-Organic Framework Nanoparticles: Targeted Cytotoxicity toward Cancer Cells.

UiO-68 metal-organic framework nanoparticles (NMOFs) are loaded with a doxorubicin drug (fluorescent dye analogs) and locked by means of structurally engineered duplex nucleic acid structures, where one strand is covalently linked to the NMOFs and the second strand is hybridized with the anchor strand. Besides the complementarity of the second strand to the anchor sequence, it includes the complementary sequence to the microRNAs (miRNA)-21 or miRNA-221 that is specific miRNA biomarker for MCF-7 breast cancer cells or OVCAR-3 ovarian cancer cells. In the presence of the respective miRNA biomarkers, the miRNA-induced displacement of the strand associated with the anchor strand proceeds, resulting in the release of DNA/miRNA duplexes. The released duplexes are, however, engineered to be digested in the presence of exonuclease III, Exo III, a process that recycles the miRNAs and provides the autonomous amplified unlocking of the NMOFs and the release of the doxorubicin load (or the fluorescent dye analogs) even at low concentrations of miRNA. Preliminary cell experiments reveal that the respective NMOFs are unlocked by the miRNA-21 or miRNA-221, resulting in selective cytotoxicity toward MCF-7 breast cancer cells or OVCAR-3 ovarian cancer cells.

Recent Advances in Subcellular Targeted Cancer Therapy Based on Functional Materials.

Recently, diverse functional materials that take subcellular structures as therapeutic targets are playing increasingly important roles in cancer therapy. Here, particular emphasis is placed on four kinds of therapies, including chemotherapy, gene therapy, photodynamic therapy (PDT), and hyperthermal therapy, which are the most widely used approaches for killing cancer cells by the specific destruction of subcellular organelles. Moreover, some non-drug-loaded nanoformulations (i.e., metal nanoparticles and molecular self-assemblies) with a fatal effect on cells by influencing the subcellular functions without the use of any drug molecules are also included. According to the basic principles and unique performances of each treatment, appropriate strategies are developed to meet task-specific applications by integrating specific materials, ligands, as well as methods. In addition, the combination of two or more therapies based on multifunctional nanostructures, which either directly target specific subcellular organelles or release organelle-targeted therapeutics, is also introduced with the intent of superadditive therapeutic effects. Finally, the related challenges of critical re-evaluation of this emerging field are presented.

Glucose-Responsive Metal-Organic-Framework Nanoparticles Act as "Smart" Sense-and-Treat Carriers.

Zeolitic Zn2+-imidazolate cross-linked framework nanoparticles, ZIF-8 NMOFs, are used as "smart" glucose-responsive carriers for the controlled release of drugs. The ZIF-8 NMOFs are loaded with the respective drug and glucose oxidase (GOx), and the GOx-mediated aerobic oxidation of glucose yields gluconic acid and H2O2. The acidification of the NMOFs' microenvironment leads to the degradation of the nanoparticles and the release of the loaded drugs. In one sense-and-treat system, GOx and insulin are loaded in the NMOFs. In the presence of glucose, the nanoparticles are unlocked, resulting in the release of insulin. The release of insulin is controlled by the concentration of glucose. In the second sense-and-treat system, the NMOFs are loaded with the antivascular endothelial growth factor aptamer (VEGF aptamer) and GOx. In the presence of glucose, the ZIF-8 NMOFs are degraded, leading to the release of the VEGF aptamer, which acts as a potential inhibitor of the angiogenetic regeneration of blood vessels by VEGF. As calcination of the VEGF-generated blood vessels leads to blindness of diabetic patients, the functional NMOFs might act as "smart" materials for the treatment of macular diseases. The potential cytotoxicity of the NMOFs originated from the GOx-generated H2O2 is resolved by the co-immobilization of the H2O2-scavanger catalase in the NMOFs.

ACPI Conjugated Gold Nanorods as Nanoplatform for Dual Image Guided Activatable Photodynamic and Photothermal Combined Therapy In Vivo.

The nanoplatform GNR-ACPP-PpIX (designated as GNR-ACPI) is designed for dual image guided combined activatable photodynamic therapy (PDT) and photothermal therapy (PTT). In GNR-ACPI, gold nanorods (GNRs) are modified with a protoporphyrin (PpIX, a PDT agent) conjugated activatable cell penetrating peptide (ACPP), which consists of the matrix metalloproteinases-2 (MMP-2) sensitive peptide sequence GPLGLAG. First, the photoactivity of PpIX is effectively quenched by GNRs due to the strong near infrared region light absorption of GNR and the special "U type" structure of ACPP induced close contact between PpIX and GNR. However, once arriving at the tumor site, the GPLGLAG sequence is hydrolyzed by the MMP-2 overexpressed by tumor cells, resulting in the release of the residual cell membrane penetrating peptide (CPP) attached PpIX (CPP-PpIX) with the recovery of photoactivity of PpIX. In addition, with the help of CPP, more efficient cellular uptake of PpIX by tumor cells can be achieved, which will greatly improve the PDT efficacy. Moreover, the GNR can also be utilized for photothermic imaging as well as PTT for tumors. It is found that the combination of PTT and PDT under the guidance of dual-mode imaging greatly enhances the antitumor effects, while possessing negligible systematic toxicity.

Overcoming the Heat Endurance of Tumor Cells by Interfering with the Anaerobic Glycolysis Metabolism for Improved Photothermal Therapy.

In this study, we developed a general method to decorate plasmonic gold nanorods (GNRs) with a CD44-targeting functional polymer, containing a hyaluronic acid (HA)-targeting moiety and a small molecule Glut1 inhibitor of diclofenac (DC), to obtain GNR/HA-DC. This nanosystem exhibited the superiority of selectively sensitizing tumor cells for photothermal therapy (PTT) by inhibiting anaerobic glycolysis. Upon specifically targeting CD44, sequentially time-dependent DC release could be achieved by the trigger of hyaluronidase (HAase), which abundantly existed in tumor tissues. The released DC depleted the Glut1 level in tumor cells and induced a cascade effect on cellular metabolism by inhibiting glucose uptake, blocking glycolysis, decreasing ATP levels, hampering heat shock protein (HSP) expression, and ultimately leaving malignant cells out from the protection of HSPs to stress (e.g., heat), and then tumor cells were more easy to kill. Owing to the sensitization effect of GNR/HA-DC, CD44 overexpressed tumor cells could be significantly damaged by PTT with an enhanced therapeutic efficiency in vitro and in vivo.

Mesoporous silica-based versatile theranostic nanoplatform constructed by layer-by-layer assembly for excellent photodynamic/chemo therapy.

Supramolecular photosensitizers (supraPSs) have emerged as effective photodynamic therapy (PDT) agents. Here, we propose the assembling capacity of supraPSs as a new strategy to construct theranostic nanoplatform with versatile functions aming at high-performance tumor therapy. By coating tirapazamine (TPZ)-loaded mesoporous silica nanoparticles (MSNs) with layer-by-layer (LbL) assembled multilayer, the versatile nanoplatform (TPZ@MCMSN-Gd3+) was obtained with the formation of supraPSs via host-guest interaction and the chelation with paramagnetic Gd3+. The TPZ@MCMSN-Gd3+ could be specifically uptaken by CD44 receptor overexpressed tumor cells and respond to hyaluronidase (HAase) to trigger the release of therapeutics. As confirmed by in vivo studies, TPZ@MCMSN-Gd3+ showed preferential accumulation in tumor site and significantly inhibited the tumor progression by the collaboration of PDT and bioreductive chemotherapy under NIR fluorescence/MR imaging guidance. Taken together, this supraPSs based strategy paves a new paradigm of the way for the construction of theranostic nanoplatform.