Recent advances in development of dendritic polymer-based nanomedicines for cancer diagnosis

Targeting nanoplatform synergistic glutathione depletion-enhanced chemodynamic, microwave dynamic, and selective-microwave thermal to treat lung cancer bone metastasis

Once bone metastasis occurs in lung cancer, the efficiency of treatment can be greatly reduced. Current mainstream treatments are focused on inhibiting cancer cell growth and preventing bone destruction. Microwave ablation (MWA) has been used to treat bone tumors. However, MWA may damage the surrounding normal tissues. Therefore, it could be beneficial to develop a nanocarrier combined with microwave to treat bone metastasis. Herein, a microwave-responsive nanoplatform (MgFe2O4@ZOL) was constructed. MgFe2O4@ZOL NPs release the cargos of Fe3+, Mg2+ and zoledronic acid (ZOL) in the acidic tumor microenvironment (TME). Fe3+ can deplete intracellular glutathione (GSH) and catalyze H2O2 to generate •OH, resulting in chemodynamic therapy (CDT). In addition, the microwave can significantly enhance the production of reactive oxygen species (ROS), thereby enabling the effective implementation of microwave dynamic therapy (MDT). Moreover, Mg2+ and ZOL promote osteoblast differentiation. In addition, MgFe2O4@ZOL NPs could target and selectively heat tumor tissue and enhance the effect of microwave thermal therapy (MTT). Both in vitro and in vivo experiments revealed that synergistic targeting, GSH depletion-enhanced CDT, MDT, and selective MTT exhibited significant antitumor efficacy and bone repair. This multimodal combination therapy provides a promising strategy for the treatment of bone metastasis in lung cancer patients.

Programmed Cascade Polydopamine Nanoclusters for Pyroptosis-Based Tumor Immunotherapy

Pyroptosis, an inflammatory cell death, plays a pivotal role in activating inflammatory response, reversing immunosuppression and enhancing anti-tumor immunity. However, challenges remain regarding how to induce pyroptosis efficiently and precisely in tumor cells to amplify anti-tumor immunotherapy. Herein, a pH-responsive polydopamine (PDA) nanocluster, perfluorocarbon (PFC)@octo-arginine (R8)-1-Hexadecylamine (He)-porphyrin (Por)@PDA-gambogic acid (GA)-cRGD (R-P@PDA-GC), is rationally design to augment phototherapy-induced pyroptosis and boost anti-tumor immunity through a two-input programmed cascade therapy. Briefly, oxygen doner PFC is encapsulated within R8 linked photosensitizer Por and He micelles as the core, followed by incorporation of GA and cRGD peptides modified PDA shell, yielding the ultimate R-P@PDA-GC nanoplatforms (NPs). The pH-responsive NPs effectively alleviate hypoxia by delivering oxygen via PFC and mitigate heat resistance in tumor cells through GA. Upon two-input programmed irradiation, R-P@PDA-GC NPs significantly enhance reactive oxygen species production within tumor cells, triggering pyroptosis via the Caspase-1/GSDMD pathway and releasing numerous inflammatory factors into the TME. This leads to the maturation of dendritic cells, robust infiltration of cytotoxic CD8+ T and NK cells, and diminution of immune suppressor Treg cells, thereby amplifying anti-tumor immunity.

Targeted Ferroptosis-Immunotherapy Synergy: Enhanced Antiglioma Efficacy with Hybrid Nanovesicles Comprising NK Cell-Derived Exosomes and RSL3-Loaded Liposomes

Ferroptosis therapy and immunotherapy have been widely used in cancer treatment. However, nonselective induction of ferroptosis in tumors is prone to immunosuppression, limiting the therapeutic effect of ferroptosis cancer treatment. To address this issue, this study reports a customized hybrid nanovesicle composed of NK cell-derived extracellular versicles and RSL3-loaded liposomes (hNRVs), aiming to establish a positive cycle between ferroptosis therapy and immunotherapy. Thanks to the enhanced permeability and retention effect and the tumor homing characteristics of NK exosomes, our data indicate that hNRVs can actively accumulate in tumors and enhance cellular uptake. FASL, IFN-γ, and RSL3 are released into the tumor microenvironment, where FASL derived from NK cells effectively lyses tumor cells. RSL3 downregulates the expression of GPX4 in the tumor, leading to the accumulation of LPO and ROS, and promotes ferroptosis in tumor cells. The accumulation of IFN-γ and TNF-α stimulates the maturation of dendritic cells and effectively induces the inactivation of GPX4, promoting lipid peroxidation, making them sensitive to ferroptosis and indirectly promoting the occurrence of ferroptosis. This study highlights the role of the customized hNRV platform in enhancing the effectiveness of synergistic treatment with selective delivery of ferroptosis inducers and immune activation against glioma without causing additional side effects on healthy organs.

Targeted drug-loaded peptides induce tumor cell apoptosis and immunomodulation to increase antitumor efficacy

Immunotherapy is an emerging approach for the treatment of solid tumors. Although chemotherapy is generally considered immunosuppressive, specific chemotherapeutic agents can induce tumor immunity. In this study, we developed a targeted, acid-sensitive peptide nanoparticle (DT/Pep1) to deliver doxorubicin (DOX) and triptolide (TPL) to breast cancer cells via the enhanced permeability and retention (EPR) effect and the breast cancer-targeting effect of peptide D8. Compared with administration of the free drugs, treatment with the DT/Pep1 system increased the accumulation of DOX and TPL at the tumor site and achieved deeper penetration into the tumor tissue. In an acidic environment, DT/Pep1 transformed from spherical nanoparticles to aggregates with a high aspect ratio, which successfully extended the retention of the drugs in the tumor cells and bolstered the anticancer effect. In both in vivo and in vitro experiments, DT/Pep1 effectively blocked the cell cycle and induced apoptosis. Importantly, the DT/Pep1 system efficiently suppressed tumor development in mice bearing 4T1 tumors while simultaneously promoting immune system activation. Thus, the results of this study provide a system for breast cancer therapy and offer a novel and promising platform for peptide nanocarrier-based drug delivery.

Reversal of Chemoresistance via Staged Liberation of Chemodrug and siRNA in Hierarchical Response to ROS Gradient

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) often leads to the failure of antitumor chemotherapy, and codelivery of chemodrug with P-gp siRNA (siP-gp) represents a promising approach for treating chemoresistant tumors. To maximize the antitumor efficacy, it is desired that the chemodrug be latently released upon completion of siP-gp-mediated gene silencing, which however, largely remains an unmet demand. Herein, core-shell nanocomplexes (NCs) are developed to overcome MDR via staged liberation of siP-gp and chemodrug (doxorubicin, Dox) in hierarchical response to reactive oxygen species (ROS) concentration gradients. The NCs are constructed from mesoporous silica nanoparticles (MSNs) surface-decorated with cRGD-modified, PEGylated, ditellurium-crosslinked polyethylenimine (RPPT), wherein thioketal-linked dimeric doxorubicin (TK-Dox2) and photosensitizer are coencapsulated inside MSNs while siP-gp is embedded in the RPPT polymeric layer. RPPT with ultrahigh ROS-sensitivity can be efficiently degraded by the low-concentration ROS inside cancer cells to trigger siP-gp release. Upon siP-gp-mediated gene silencing and MDR reversal, light irradiation is performed to generate high-concentration, lethal amount of ROS, which cleaves thioketal with low ROS-sensitivity to liberate the monomeric Dox. Such a latent release profile greatly enhances Dox accumulation in Dox-resistant cancer cells (MCF-7/ADR) in vitro and in vivo, which cooperates with the generated ROS to efficiently eradicate MCF-7/ADR xenograft tumors.

Dendritic Polymer-Based Nanomedicines Remodel the Tumor Stroma: Improve Drug Penetration and Enhance Antitumor Immune Response

The dense extracellular matrix (ECM) in solid tumors, contributed by cancer-associated fibroblasts (CAFs), hinders penetration of drugs and diminishes their therapeutic outcomes. A sequential treatment strategy of remodeling the ECM via a CAF modifier (dasatinib, DAS) is proposed to promote penetration of an immunogenic cell death (ICD) inducer (epirubicin, Epi) via apoptotic vesicles, ultimately enhancing the treatment efficacy against breast cancer. Dendritic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)-based nanomedicines (poly[OEGMA-Dendron(G2)-Gly-Phe-Leu-Gly-DAS] (P-DAS) and poly[OEGMA-Dendron(G2)-hydrazone-Epi] (P-Epi)) are developed for sequential delivery of DAS and Epi, respectively. P-DAS reprograms CAFs to reduce collagen by downregulating collagen anabolism and energy metabolism, thereby reducing the ECM deposition. The regulated ECM can enhance tumor penetration of P-Epi to strengthen its ICD effect, leading to an amplified antitumor immune response. In breast cancer-bearing mice, this approach alleviates the ECM barrier, resulting in reduced tumor burden and increased cytotoxic T lymphocyte infiltration, and more encouragingly, synergizes effectively with anti-programmed cell death 1 (PD-1) therapy, significantly inhibiting tumor growth and preventing lung metastasis. Furthermore, systemic toxicity is barely detectable after sequential treatment with P-DAS and P-Epi. This approach opens a new avenue for treating desmoplastic tumors by metabolically targeting CAFs to overcome the ECM barrier.

Dendronized Polymer-Derived Nanomedicines for Mitochondrial Dynamics Regulation and Immune Modulation

The effects of dendron side chains in polymeric conjugates on tumor penetration and antigen presentation are systematically examined. Three polymer-gemcitabine (Gem) conjugates (pG0-Gem, pG1-Gem, pG2-Gem) are designed and prepared. The pG2-Gem conjugate uniquely binds to the mitochondria of tumor cells, thus regulating mitochondrial dynamics. The interaction between the pG2-Gem conjugate and the mitochondria promotes great penetration and accumulation of the conjugate at the tumor site, resulting in pronounced antitumor effects in an animal model. Such encouraging therapeutic effects can be ascribed to immune modulation since MHC-1 antigen presentation is significantly enhanced due to mitochondrial fusion and mitochondrial metabolism alteration after pG2-Gem treatment. Crucially, the drug-free dendronized polymer, pG2, is identified to regulate mitochondrial dynamics, and the regulation is independent of the conjugated Gem. Furthermore, the combination of pG2-Gem with anti-PD-1 antibody results in a remarkable tumor clearance rate of 87.5% and a prolonged survival rate of over 150 days, demonstrating the potential of dendronized polymers as an innovative nanoplatform for metabolic modulation and synergistic tumor immunotherapy.

Preparation of PMMA-Based Temperature/pH Responsive Nanoparticles Encapsulating 5-Fluorouracil and Methotrexate In Situ by One-Pot Dispersion Photopolymerization

In order to achieve long-term and controllable release of anti-tumor drugs at specific sites, temperature/pH responsive nanoparticles encapsulating 5-fluorouracil and methotrexate in situ are prepared through dispersion photopolymerization under green LED irradiation. The physicochemical properties of nanoparticles are characterized by scanning electron microscopy, Fourier transform infrared, dynamic light scattering, thermogravimetric/differential scanning calorimetry, and X-ray diffraction. In vitro drug release at different temperatures and pH values is examined to ascertain the release pattern of two drugs, which can be well described by Korsmeyer-Peppas kinetic model. The cytotoxicity evaluation illustrates that the tumor cells could be more effectively killed by the drug-loaded nanoparticles, and the improved therapeutic effect is attributed to the controllable and sustainable drug release as well as the enhanced cellular uptake. The blood safety and good biocompatibility of nanoparticles are further confirmed by hemolysis assay, indicating the prepared nanoparticles are potential candidates for effective tumor treatment.

Reversing cancer immunoediting phases with a tumor-activated and optically reinforced immunoscaffold

In situ vaccine (ISV) is a promising immunotherapeutic tactic due to its complete tumoral antigenic repertoire. However, its efficiency is limited by extrinsic inevitable immunosuppression and intrinsic immunogenicity scarcity. To break this plight, a tumor-activated and optically reinforced immunoscaffold (TURN) is exploited to trigger cancer immunoediting phases regression, thus levering potent systemic antitumor immune responses. Upon response to tumoral reactive oxygen species, TURN will first release RGX-104 to attenuate excessive immunosuppressive cells and cytokines, and thus immunosuppression falls and immunogenicity rises. Subsequently, intermittent laser irradiation-activated photothermal agents (PL) trigger abundant tumor antigens exposure, which causes immunogenicity springs and preliminary infiltration of T cells. Finally, CD137 agonists from TURN further promotes the proliferation, function, and survival of T cells for durable antitumor effects. Therefore, cancer immunoediting phases reverse and systemic antitumor immune responses occur. TURN achieves over 90 % tumor growth inhibition in both primary and secondary tumor lesions, induces potent systemic immune responses, and triggers superior long-term immune memory in vivo. Taken together, TURN provides a prospective sight for ISV from the perspective of immunoediting phases.

mRNA-responsive two-in-one nanodrug for enhanced anti-tumor chemo-gene therapy

The combination of chemotherapy and gene therapy holds great promise for the treatment and eradication of tumors. However, due to significant differences in physicochemical properties between chemotherapeutic agents and functional nucleic acid drugs, direct integration into a single nano-agent is hindered, impeding the design and construction of an effective co-delivery nano-platform for synergistic anti-tumor treatments. In this study, we have developed an mRNA-responsive two-in-one nano-drug for effective anti-tumor therapy by the direct self-assembly of 2'-fluoro-substituted antisense DNA against P-glycoprotein (2'F-DNA) and chemo drug paclitaxel (PTX). The 2'-fluoro modification of DNA could significantly increase the interaction between the therapeutic nucleic acid and the chemotherapeutic drug, promoting the successful formation of 2'F-DNA/PTX nanospheres (2'F-DNA/PTX NSs). Due to the one-step self-assembly process without additional carrier materials, the prepared 2'F-DNA/PTX NSs exhibited considerable loading efficiency and bioavailability of PTX. In the presence of endogenous P-glycoprotein mRNA, the 2'F-DNA/PTX NSs were disassembled. The released 2'F-DNA could down-regulate the expression of P-glycoprotein, which decreased the multidrug resistance of tumor cells and enhanced the chemotherapy effect caused by PTX. In this way, the 2'F-DNA/PTX NSs could synergistically induce the apoptosis of tumor cells and realize the combined anti-tumor therapy. This strategy might provide a new tool to explore functional intracellular co-delivery nano-systems with high bioavailability and exhibit potential promising in the applications of accurate diagnosis and treatment of tumors.

Mitocytosis Mediated by an Enzyme-Activable Mitochondrion-Disturbing Polymer-Drug Conjugate Enhances Active Penetration in Glioblastoma Therapy

The application of nanomedicines for glioblastoma (GBM) therapy is hampered by the blood-brain barrier (BBB) and the dense glioblastoma tissue. To achieve efficient BBB crossing and deep GBM penetration, this work demonstrates a strategy of active transcellular transport of a mitochondrion-disturbing nanomedicine, pGBEMA22-b-pSSPPT9 (GBEPPT), in the GBM tissue through mitocytosis. GBEPPT is computer-aided designed and prepared by self-assembling a conjugate of an amphiphilic block polymer and a drug podophyllotoxin (PPT). When GBEPPT is delivered to the tumor site, overexpressed γ-glutamyl transpeptidase (GGT) on the brain-blood endothelial cell, or the GBM cell triggered enzymatic hydrolysis of γ-glutamylamide on GBEPPT to reverse its negative charge to positive. Positively charged GBEPPT rapidly enter into the cell and target the mitochondria. These GBEPPT disturb the homeostasis of mitochondria, inducing mitocytosis-mediated extracellular transport of GBEPPT to the neighboring cells via mitosomes. This intracellular-to-intercellular delivery cycle allows GBEPPT to penetrate deeply into the GBM parenchyma, and exert sustainable action of PPT released from GBEPPT on the tumor cells along its penetration path at the tumor site, thus improving the anti-GBM effect. The process of mitocytosis mediated by the mitochondrion-disturbing nanomedicine may offer great potential in enhancing drug penetration through malignant tissues, especially poorly permeable solid tumors.

Nanoassembly-Mediated Exendin-4 Derivatives to Decrease Renal Retention

An Exendin-4 analogue that was conjugated with 68Ga exhibited an excellent diagnostic effect on insulinoma in clinical practice. On account of its low molecular weight and short hydration radius, 68Ga-Exendin-4 showed high accumulation in kidney tissues. Nanoparticle-mediated strategies have attracted much attention due to polyvalent properties and the size amplification effect. In this study, Exendin-4 derivatives of radionuclide nanodevices were developed and evaluated. The Exendin-4 derivatives consisting of a ternary block recombinant protein were purified by an inverse transition cycle (ITC) and allowed to self-assemble into a nanodevice under physiological conditions. Our results showed that the nanoassemblies of Exendin-4 derivatives formed homogeneous spherical nanoparticles, exhibited outstanding affinity for insulinoma cells, and could be deposited in insulinoma tissues in vivo. The nanoassembly-mediated Exendin-4 derivatives showed fivefold reduced renal retention and exhibited an outstanding tumor-suppression effect.

Combating bone marrow failure with polymer materials

Bone marrow failure (BMF) has become one of the most studied autoimmune disorders, particularly due to its prevalence both as an inherited disease, but also as a result of chemotherapies. BMF is associated with severe symptoms such as bleeding episodes and susceptibility to infections, and often has underlying characteristics, such as anemia, thrombocytopenia, and neutropenia. The current treatment landscape for BMF requires stem cell transplantation or chemotherapies to induce immune suppression. However, there is limited donor cell availability or dose related toxicity associated with these treatments. Optimizing these treatments has become a necessity. Polymer-based materials have become increasingly popular, as current research efforts are focused on synthesizing novel cell matrices for stem cell expansion to solve limited donor cell availability, as well as applying polymer delivery vehicles to intracellularly deliver cargo that can aid in immunosuppression. Here, we discuss the importance and impact of polymer materials to enhance therapeutics in the context of BMF.

Isoliquiritigenin Containing PH Sensitive Micelles for Enhanced Anti-Colitis Activity

Isoliquiritigenin (ISL) is known to have a variety of pharmacological activities, but its poor water solubility limits its application. In order to improve the bioavailability of ISL and its anti-colitis activity, this study aims to develop an effective drug delivery system loaded with ISL. In this study, ISL pH-sensitive micelles (ISL-M) were prepared by thin film hydration method. The micellar size (PS), polydispersity index (PDI), electrokinetic potential (ζ-potential), drug loading (DL), encapsulation rate (EE) and other physical parameters were characterized. The storage stability of ISL-M was tested, release in vitro and pharmacokinetic studies in rats were performed, and the anti-inflammatory effect of ISL-M on ulcerative colitis induced by dextran sulfate sodium (DSS) was evaluated. The results showed that PS, PDI, ZP, EE% and DL% of ISL-M were 151.15±1.04 nm, 0.092±0.014, -31.32±0.721 mV, 93.97±1.53 % and 8.42±0.34 %, respectively. Compared with unformulated ISL (F-ISL), the cumulative release rate of ISL-M in the three different media was significantly increased and showed a certain pH sensitivity. The area under drug curve (AUC0-t) and peak concentration (Cmax) of ISL-M group were 2.94 and 4.06 times higher than those of ISL group. In addition, ISL-M is expected to develop new methods for increasing the bioavailability and anti-inflammatory activity of ISL.

Kilogram-Scale Synthesis of Extremely Small Gadolinium Oxide Nanoparticles as a T1-Weighted Contrast Agent for Magnetic Resonance Imaging

Magnetic resonance imaging contrast agents are frequently used in clinics to enhance the contrast between diseased and normal tissues. The previously reported poly(acrylic acid) stabilized exceedingly small gadolinium oxide nanoparticles (ES-GdON-PAA) overcame the problems of commercial Gd chelates, but limitations still exist, i.e., high r2/r1 ratio, long blood circulation half-life, and no data for large scale synthesis and formulation optimization. In this study, polymaleic acid (PMA) is found to be an ideal stabilizer to synthesize ES-GdONs. Compared with ES-GdON-PAA, the PMA-stabilized ES-GdON (ES-GdON-PMA) has a lower r2/r1 ratio (2.05, 7.0 T) and a lower blood circulation half-life (37.51 min). The optimized ES-GdON-PMA-9 has an exceedingly small particle size (2.1 nm), excellent water dispersibility, and stability. A facile, efficient, and environmental friendly synthetic method is developed for large-scale synthesis of the ES-GdONs-PMA. The weight of the optimized freeze-dried ES-GdON-PMA-26 synthesized in a 20 L of reactor reaches the kilogram level. The formulation optimization is also finished, and the concentrated ES-GdON-PMA-26 formulation (CGd = 100 mm) after high-pressure steam sterilization possesses eligible physicochemical properties (i.e., pH value, osmolality, viscosity, and density) for investigational new drug application.

Preparation of novel shell-ionotropically crosslinked micelles based on hexadecylamine and tripolyphosphate for cancer drug delivery

AIMS

Micellar systems have the advantage of being easily prepared, cheap, and readily loadable with bioactive molecular cargo. However, their fundamental pitfall is poor stability, particularly under dilution conditions. We propose to use simple quaternary ammonium surfactants, namely, hexadecylamine (HDA) and hexadecylpyridinium (HDAP), together with tripolyphosphate (TPP) anion, to generate ionotropically stabilized micelles capable of drug delivery into cancer cells.

METHODS

optimized mixed HDA/HDAP micelles were prepared and stabilized with TPP. Curcumin was used as a loaded model drug. The prepared nanoparticles were characterized by dynamic light scattering, infrared spectroscopy, transmission electron microscopy, and differential scanning calorimetry. Moreover, their cellular uptake was assessed using flow cytometry and confocal fluorescence microscopy.

RESULTS

The prepared nanoparticles were found to be stable under dilution and at high temperatures and to have a size range from 139 nm to 580 nm, depending on pH (4.6-7.4), dilution (up to 100 times), and temperature (25 - 80 °C). They were effective at delivering their load into cancer cells. Additionally, flow cytometry indicated the resulting stabilized micellar nanoparticles to be non-cytotoxic.

CONCLUSIONS

The described novel stabilized micelles are simple to prepare and viable for cancer delivery.

Homomultivalent Polymeric Nanotraps Disturb Lipid Metabolism Homeostasis and Tune Pyroptosis in Cancer

Genetic manipulations and pharmaceutical interventions to disturb lipid metabolism homeostasis have emerged as an attractive approach for the management of cancer. However, the research on the utilization of bioactive materials to modulate lipid metabolism homeostasis remains constrained. In this study, heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin (TMCD) is utilized to fabricate homomultivalent polymeric nanotraps, and surprisingly, its unprecedented ability to perturb lipid metabolism homeostasis and induce pyroptosis in tumor cells is found. Through modulation of the density of TMCD arrayed on the polymers, one top-performing nanotrap, PTMCD4, exhibits the most powerful cholesterol-trapping and depletion capacity, thus achieving prominent cytotoxicity toward different types of tumor cells and encouraging antitumor effects in vivo. The interactions between PTMCD4 and biomembranes of tumor cells effectively enable the reduction of cellular phosphatidylcholine and cholesterol levels, thus provoking damage to the biomembrane integrity and perturbation of lipid metabolism homeostasis. Additionally, the interplays between PTMCD4 and lysosomes also induce lysosomal stress, activate the nucleotide-binding oligomerization domain-like receptor protein 3 inflammasomes, and subsequently trigger tumor cell pyroptosis. To sum up, this study first introduces dendronized bioactive polymers to manipulate lipid metabolism and has shed light on another innovative insight for cancer therapy.

Bioorthogonal In Situ Polymerization of Dendritic Agents for Hijacking Lysosomes and Enhancing Antigen Presentation in Cancer Cells

A low-generation lysine dendrimer, SPr-G2, responds to intracellular glutathione to initiate bioorthogonal in situ polymerization, resulting in the formation of large assemblies in mouse breast cancer cells. The intracellular large assemblies of SPr-G2 can interact with lysosomes to induce lysosome expansion and enhance lysosomal membrane permeabilization, leading to major histocompatibility complex class I upregulation on tumor cell surfaces and ultimately tumor cell death. Moreover, the use of the SPr-G2 dendrimer to conjugate the chemotherapeutic drug, camptothecin (CPT), can boost the therapeutic potency of CPT. Excellent antitumor effects in vitro and in vivo are obtained from the combinational treatment of the SPr-G2 dendrimer and CPT. This combinational effect also enhances antitumor immunity through promoting activation of cytotoxic T cells in tumor tissues and maturation of dendritic cells. This study can shed new light on the development of peptide dendritic agents for cancer therapy.

Unraveling Ros Conversion Through Enhanced Enzyme-Like Activity with Copper-Doped Cerium Oxide for Tumor Nanocatalytic Therapy

Nanozyme catalytic therapy for cancer treatments has become one of the heated topics, and the therapeutic efficacy is highly correlated with their catalytic efficiency. In this work, three copper-doped CeO2 supports with various structures as well as crystal facets are developed to realize dual enzyme-mimic catalytic activities, that is superoxide dismutase (SOD) to reduce superoxide radicals to H2 O2 and peroxidase (POD) to transform H2 O2 to ∙OH. The wire-shaped CeO2 /Cu-W has the richest surface oxygen vacancies, and a low level of oxygen vacancy (Vo) formation energy, which allows for the elimination of intracellular reactive oxygen spieces (ROS) and continuous transformation to ∙OH with cascade reaction. Moreover, the wire-shaped CeO2 /Cu-W displays the highest toxic ∙OH production capacity in an acidic intracellular environment, inducing breast cancer cell death and pro-apoptotic autophagy. Therefore, wire-shaped CeO2 /Cu nanoparticles as an artificial enzyme system can have great potential in the intervention of intracellular ROS in cancer cells, achieving efficacious nanocatalytic therapy.

Data mining and analysis of the adverse events derived signals of 4 gadolinium-based contrast agents based on the US Food and drug administration adverse event reporting system

BACKGROUND

To detect and analyze risk signals of the drug-related adverse events (AEs) of 4 gadolinium-based contrast agents (GBCAs) (gadopentetate dimeglumine (Gd-DTPA), gadobenate dimeglumine (Gd-BOPTA), gadoteridol (Gd-HP-DO3A), and gadobutrol (Gd-BT-DO3A)) according to the US Food and Drug Administration Adverse Event Reporting System (FAERS) database and ensure the clinical safety.

RESEARCH DESIGN AND METHODS

The AEs that are associated with the 4 GBCAs were collected from the FAERS database from 2004Q1 to 2022Q3. The risk signals were mined using reporting odds ratio (ROR) and proportional reporting ratio (PRR).

RESULTS

424 risk signals were excavated, in which 151 risk signals were associated with Gd-DTPA, 93 risk signals were related to Gd-BOPTA, 79 risk signals were relevant to Gd-HP-DO3A, and 101 risk signals were associated with Gd-BT-DO3A. The AE signals involved 20 system organ classes (SOCs). Two of the top four SOCs were identical, namely 'skin and subcutaneous tissue disorders' and 'general disorders and administration site conditions.'

CONCLUSIONS

The safety signals of 4 GBCAs were detected, and the SOCs associated with the AEs of the 4 GBCAs were different. Besides, some AEs obtained in this study were not mentioned in the package inserts, which need more attention and research to ensure the clinical safety.

Microwave-responsive gadolinium metal-organic frameworks nanosystem for MRI-guided cancer thermotherapy and synergistic immunotherapy

The clinical application of cancer immunotherapy is unsatisfied due to low response rates and systemic immune-related adverse events. Microwave hyperthermia can be used as a synergistic immunotherapy to amplify the antitumor effect. Herein, we designed a Gd-based metal-organic framework (Gd-MOF) nanosystem for MRI-guided thermotherapy and synergistic immunotherapy, which featured high performance in drug loading and tumor tissue penetration. The PD-1 inhibitor (aPD-1) was initially loaded in the porous Gd-MOF (Gd/M) nanosystem. Then, the phase change material (PCM) and the cancer cell membrane were further sequentially modified on the surface of Gd/MP to obtain Gd-MOF@aPD-1@CM (Gd/MPC). When entering the tumor microenvironment (TME), Gd/MPC induces immunogenic death of tumor cells through microwave thermal responsiveness, improves tumor suppressive immune microenvironment and further enhances anti-tumor ability of T cells by releasing aPD-1. Meanwhile, Gd/MPC can be used for contrast-enhanced MRI. Transcriptomics data revealed that the downregulation of MSK2 in cancer cells leads to the downregulation of c-fos and c-jun, and ultimately leads to the apoptosis of cancer cells after treatment. In general, Gd/MPC nanosystem not only solves the problem of system side effect, but also achieves the controlled drug release via PCM, providing a promising theranostic nanoplatform for development of cancer combination immunotherapy.

Nose-to-brain delivery of nanotherapeutics: Transport mechanisms and applications

The blood-brain barrier presents a key limitation to the administration of therapeutic molecules for the treatment of brain disease. While drugs administered orally or intravenously must cross this barrier to reach brain targets, the unique anatomical structure of the olfactory system provides a route to deliver drugs directly to the brain. Entering the brain via receptor, carrier, and adsorption-mediated transcytosis in the nasal olfactory and trigeminal regions has the potential to increase drug delivery. In this review, we introduce the physiological and anatomical structures of the nasal cavity, and summarize the possible modes of transport and the relevant receptors and carriers in the nose-to-brain pathway. Additionally, we provide examples of nanotherapeutics developed for intranasal drug delivery to the brain. Further development of nanoparticles that can be applied to intranasal delivery systems promises to improve drug efficacy and reduce drug resistance and adverse effects by increasing molecular access to the brain. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease.

Opportunities and Challenges for Inhalable Nanomedicine Formulations in Respiratory Diseases: A Review

Lungs experience frequent interactions with the external environment and have an abundant supply of blood; therefore, they are susceptible to invasion by pathogenic microorganisms and tumor cells. However, the limited pharmacokinetics of conventional drugs in the lungs poses a clinical challenge. The emergence of different nano-formulations has been facilitated by advancements in nanotechnology. Inhaled nanomedicines exhibit better targeting and prolonged therapeutic effects. Although nano-formulations have great potential, they still present several unknown risks. Herein, we review the (1) physiological anatomy of the lungs and their biological barriers, (2) pharmacokinetics and toxicology of nanomaterial formulations in the lungs; (3) current nanomaterials that can be applied to the respiratory system and related design strategies, and (4) current applications of inhaled nanomaterials in treating respiratory disorders, vaccine design, and imaging detection based on the characteristics of different nanomaterials. Finally, (5) we analyze and summarize the challenges and prospects of nanomaterials for respiratory disease applications. We believe that nanomaterials, particularly inhaled nano-formulations, have excellent prospects for application in respiratory diseases. However, we emphasize that the simultaneous toxic side effects of biological nanomaterials must be considered during the application of these emerging medicines. This study aims to offer comprehensive guidelines and valuable insights for conducting research on nanomaterials in the domain of the respiratory system.

The Use of Microspheres for Cancer Embolization Therapy: Recent Advancements and Prospective

Embolization therapy involving biomaterials has improved the therapeutic strategy for most liver cancer treatments. Developing biomaterials as embolic agents has significantly improved patients' survival rates. Various embolic agents are present in liquid agents, foam, particulates, and particles. Some of the most applied embolic agents are microparticles, such as microspheres (3D micrometer-sized spherical particles). Microspheres with added functionalities are currently being developed for effective therapeutic embolization. Their excellent properties of high surface area and capacity for being loaded with radionuclides and alternate active or therapeutic agents provide an additional advantage to overcome limitations from traditional cancer treatments. Microspheres (non-radioactive and radioactive) have been widely used and explored for localized cancer treatment. Non-radioactive microspheres exhibit improved clinical performance as drug delivery vehicles in chemotherapy due to their controlled and sustained drug release to the target site. They offer better flow properties and are beneficial for the ease of delivery via injection procedures. In addition, radioactive microspheres have also been exploited for use as an embolic platform in internal radiotherapy as an alternative to cancer treatment. This short review summarizes the progressive development of non-radioactive and radioactive embolic microspheres, emphasizing material characteristics. The use of embolic microspheres for various modalities of therapeutic arterial embolization and their impact on therapeutic performance are also discussed.

Modular Self-Assembling Dendrimer Nanosystems for Magnetic Resonance and Multimodality Imaging of Tumors

Bioimaging is a powerful tool for diagnosing tumors but remains limited in terms of sensitivity and specificity. Nanotechnology-based imaging probes able to accommodate abundant imaging units with different imaging modalities are particularly promising for overcoming these limitations. In addition, the nanosized imaging agents can specifically increase the contrast of tumors by exploiting the enhanced permeability and retention effect. A proof-of-concept study is performed on pancreatic cancer to demonstrate the use of modular amphiphilic dendrimer-based nanoprobes for magnetic resonance (MR) imaging (MRI) or MR/near-infrared fluorescence (NIRF) multimodality imaging. Specifically, the self-assembly of an amphiphilic dendrimer bearing multiple Gd3+ units at its terminals, generates a nanomicellar agent exhibiting favorable relaxivity for MRI with a good safety profile. MRI reveals an up to two-fold higher contrast enhancement in tumors than in normal muscle. Encapsulating the NIRF dye within the core of the nanoprobe yields an MR/NIRF bimodal imaging agent for tumor detection that is efficient both for MRI, at Gd3+ concentrations 1/10 the standard clinical dose, and for NIRF imaging, allowing over two-fold stronger fluorescence intensities. These self-assembling dendrimer nanosystems thus constitute effective probes for MRI and MR/NIRF multimodality imaging, offering a promising nanotechnology platform for elaborating multimodality imaging probes in biomedical applications.

Erythrocyte-Leveraged Oncolytic Virotherapy (ELeOVt): Oncolytic Virus Assembly on Erythrocyte Surface to Combat Pulmonary Metastasis and Alleviate Side Effects

Despite being a new promising tool for cancer therapy, intravenous delivery of oncolytic viruses (OVs) is greatly limited by poor tumor targeting, rapid clearance in the blood, severe organ toxicity, and cytokine release syndrome. Herein, a simple and efficient strategy of erythrocyte-leveraged oncolytic virotherapy (ELeOVt) is reported, which for the first time assembled OVs on the surface of erythrocytes with up to near 100% efficiency and allowed targeted delivery of OVs to the lung after intravenous injection to achieve excellent treatment of pulmonary metastases while greatly improving the biocompatibility of OVs as a drug. Polyethyleneimine (PEI) as a bridge to assemble OVs on erythrocytes also played an important role in promoting the transfection of OVs. It is found that ELeOVt approach significantly prolonged the circulation time of OVs and increased the OVs distribution in the lung by more than tenfold, thereby significantly improving the treatment of lung metastases while reducing organ and systemic toxicity. Taken together, these findings suggest that the ELeOVt provides a biocompatible, efficient, and widely available approach to empower OVs to combat lung metastasis.

Enhancing drug penetration in solid tumors via nanomedicine: Evaluation models, strategies and perspectives

Effective tumor treatment depends on optimizing drug penetration and accumulation in tumor tissue while minimizing systemic toxicity. Nanomedicine has emerged as a key solution that addresses the rapid clearance of free drugs, but achieving deep drug penetration into solid tumors remains elusive. This review discusses various strategies to enhance drug penetration, including manipulation of the tumor microenvironment, exploitation of both external and internal stimuli, pioneering nanocarrier surface engineering, and development of innovative tactics for active tumor penetration. One outstanding strategy is organelle-affinitive transfer, which exploits the unique properties of specific tumor cell organelles and heralds a potentially transformative approach to active transcellular transfer for deep tumor penetration. Rigorous models are essential to evaluate the efficacy of these strategies. The patient-derived xenograft (PDX) model is gaining traction as a bridge between laboratory discovery and clinical application. However, the journey from bench to bedside for nanomedicines is fraught with challenges. Future efforts should prioritize deepening our understanding of nanoparticle-tumor interactions, re-evaluating the EPR effect, and exploring novel nanoparticle transport mechanisms.

Spatially Asymmetric Nanoparticles for Boosting Ferroptosis in Tumor Therapy

Despite its effectiveness in eliminating cancer cells, ferroptosis is hindered by the high natural antioxidant glutathione (GSH) levels in the tumor microenvironment. Herein, we developed a spatially asymmetric nanoparticle, Fe3O4@DMS&PDA@MnO2-SRF, for enhanced ferroptosis. It consists of two subunits: Fe3O4 nanoparticles coated with dendritic mesoporous silica (DMS) and PDA@MnO2 (PDA: polydopamine) loaded with sorafenib (SRF). The spatial isolation of the Fe3O4@DMS and PDA@MnO2-SRF subunits enhances the synergistic effect between the GSH-scavengers and ferroptosis-related components. First, the increased exposure of the Fe3O4 subunit enhances the Fenton reaction, leading to increased production of reactive oxygen species. Furthermore, the PDA@MnO2-SRF subunit effectively depletes GSH, thereby inducing ferroptosis by the inactivation of glutathione-dependent peroxidases 4. Moreover, the SRF blocks Xc- transport in tumor cells, augmenting GSH depletion capabilities. The dual GSH depletion of the Fe3O4@DMS&PDA@MnO2-SRF significantly weakens the antioxidative system, boosting the chemodynamic performance and leading to increased ferroptosis of tumor cells.

Enzyme-Responsive Branched Glycopolymer-Based Nanoassembly for Co-Delivery of Paclitaxel and Akt Inhibitor toward Synergistic Therapy of Gastric Cancer

Combined chemotherapy and targeted therapy holds immense potential in the management of advanced gastric cancer (GC). GC tissues exhibit an elevated expression level of protein kinase B (AKT), which contributes to disease progression and poor chemotherapeutic responsiveness. Inhibition of AKT expression through an AKT inhibitor, capivasertib (CAP), to enhance cytotoxicity of paclitaxel (PTX) toward GC cells is demonstrated in this study. A cathepsin B-responsive polymeric nanoparticle prodrug system is employed for co-delivery of PTX and CAP, resulting in a polymeric nano-drug BPGP@CAP. The release of PTX and CAP is triggered in an environment with overexpressed cathepsin B upon lysosomal uptake of BPGP@CAP. A synergistic therapeutic effect of PTX and CAP on killing GC cells is confirmed by in vitro and in vivo experiments. Mechanistic investigations suggested that CAP may inhibit AKT expression, leading to suppression of the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway. Encouragingly, CAP can synergize with PTX to exert potent antitumor effects against GC after they are co-delivered via a polymeric drug delivery system, and this delivery system helped reduce their toxic side effects, which provides an effective therapeutic strategy for treating GC.

Dendritic Nanomedicine with Boronate Bonds for Augmented Chemo-Immunotherapy via Synergistic Modulation of Tumor Immune Microenvironment

Unsatisfied tumor accumulation of chemotherapeutic drugs and a complicated immunosuppressive microenvironment diminish the immune response rate and the therapeutic effect. Surface modification of these drugs with target ligands can promote their cellular internalization, but the modified drugs may be subjected to unexpected immune recognition and clearance. Herein, a phenylboronic acid (PBA) group-shieldable dendritic nanomedicine that integrates an immunogenic cell death (ICD)-inducing agent (epirubicin, Epi) and an indoleamine 2,3-dioxgenase 1 (IDO1) inhibitor (NLG919) is reported for tumor chemo-immunotherapy. This NLG919-loaded Epi-conjugated PEGylated dendrimers bridged with boronate bonds (NLG919@Epi-DBP) maintains a stable nanostructure during circulation. Under a moderate acidic condition, the PBA group exposes to the sialic acid residue on the tumor cell membrane to enhance the internalization and penetration of NLG919@Epi-DBP. At pH 5.0, NLG919@Epi-DBP rapidly disassembles to release the incorporated Epi and NLG919. Epi triggers robust ICD of tumor cells that evokes strong immune response. In addition, inhibition of the IDO1 activity downregulates the metabolism of L-tryptophan to kynurenine, leading to a reduction in the recruitment of immunosuppressive cells and modulation of the tumor immune microenvironment. Collectively, this promising strategy has been demonstrated to evoke robust immune response as well as remodel the immunosuppressive microenvironment for an enhanced chemo-immunotherapeutic effect.

Design and synthesis of bioinspired nanomaterials for biomedical application

Natural materials and bioprocesses provide abundant inspirations for the design and synthesis of high-performance nanomaterials. In the past several decades, bioinspired nanomaterials have shown great potential in the application of biomedical fields, such as tissue engineering, drug delivery, and cancer therapy, and so on. In this review, three types of bioinspired strategies for biomedical nanomaterials, that is, inspired by the natural structures, biomolecules, and bioprocesses, are mainly introduced. We summarize and discuss the design concepts and synthesis approaches of various bioinspired nanomaterials along with their specific roles in biomedical applications. Additionally, we discuss the challenges for the development of bioinspired biomedical nanomaterials, such as mechanical failure in wet environment, limitation in scale-up fabrication, and lack of deep understanding of biological properties. It is expected that the development and clinical translation of bioinspired biomedical nanomaterials will be further promoted under the cooperation of interdisciplinary subjects in future. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Satellite-Type Sulfur Atom Distribution in Trithiocarbonate Bond-Bridged Dimeric Prodrug Nanoassemblies: Achieving Both Stability and Activatability

Homodimeric prodrug nanoassemblies (HDPNs) hold promise for improving the delivery efficiency of chemo-drugs. However, the key challenge lies in designing rational chemical linkers that can simultaneously ensure the chemical stability, self-assembly stability, and site-specific activation of prodrugs. The "in series" increase in sulfur atoms, such as trisulfide bond, can improve the assembly stability of HDPNs to a certain extent, but limits the chemical stability of prodrugs. Herein, trithiocarbonate bond (─SC(S)S─), with a stable "satellite-type" distribution of sulfur atoms, is developed via the insertion of a central carbon atom in trisulfide bonds. ─SC(S)S─ bond effectively addresses the existing predicament of HDPNs by improving the chemical and self-assembly stability of homodimeric prodrugs while maintaining the on-demand bioactivation. Furthermore, ─SC(S)S─ bond inhibits antioxidant defense system, leading to up-regulation of the cellular ROS and apoptosis of tumor cells. These improvements of ─SC(S)S─ bond endow the HDPNs with in vivo longevity and tumor specificity, ultimately enhancing the therapeutic outcomes. ─SC(S)S─ bond is, therefore, promising for overcoming the bottleneck of HDPNs for efficient oncological therapy.

Boosting Reactive Oxygen Species Generation with a Dual-Catalytic Nanomedicine for Enhanced Tumor Nanocatalytic Therapy

Generating lethal reactive oxygen species (ROS) within tumors by nanocatalytic medicines is an advanced strategy for tumor-specific therapy in recent years. Nevertheless, the low yield of ROS restrains its therapeutic efficiency. Herein, a dual-catalytic nanomedicine based on tumor microenvironment (TME)-responsive liposomal nanosystem co-delivering CuO2 and dihydroartemisinin (DHA) (LIPSe@CuO2&DHA) is developed to boost ROS generation against tumor. The liposomal nanosystem can degrade in the ROS-overexpressed TME and liberate CuO2 and DHA to initiate Cu-based dual-catalytic ROS generation. Serving as generators of H2O2 and Cu2+, CuO2 can self-produce plenty of toxic hydroxyl radicals via Fenton-like reaction in the acidic TME. Meanwhile, the released Cu2+ can catalyze DHA to generate cytotoxic C-centered radicals. Together, the self-supplied H2O2 and Cu-based dual-catalytic reaction greatly increase the intratumoral level of lethal ROS. Importantly, Cu2+ can decrease the GSH-mediated scavenging effect on the produced ROS via a redox reaction and undergo a Cu2+-to-Cu+ conversion to enhance the Fenton-like reaction, further guaranteeing the high efficiency of ROS generation. Resultantly, LIPSe@CuO2&DHA induces remarkable cancer cell death and tumor growth inhibition, which may present a promising nanocatalytic medicine for cancer therapy.

Manganese Dioxide-Entrapping Dendrimers Co-Deliver Protein and Nucleotide for Magnetic Resonance Imaging-Guided Chemodynamic/Starvation/Immune Therapy of Tumors

Development of a nanoscale drug delivery system that can simultaneously exert efficient tumor therapeutic efficacy while creating the desired antitumor immune responses is still challenging. Herein, we report the use of a manganese dioxide (MnO2)-entrapping dendrimer nanocarrier to codeliver glucose oxidase (GOx) and cyclic GMP-AMP (cGAMP), an agonist of the stimulator of interferon genes (STING) for improved tumor chemodynamic/starvation/immune therapy. Methoxy poly(ethylene glycol) (mPEG)- and phenylboronic acid (PBA)-modified generation 5 (G5) poly(amidoamine) dendrimers were first synthesized and then entrapped with MnO2 nanoparticles (NPs) to generate the hybrid MnO2@G5-mPEG-PBA (MGPP) NPs. The created MGPP NPs with an MnO2 core size of 2.8 nm display efficient glutathione depletion ability, and a favorable Mn2+ release profile under a tumor microenvironment mimetic condition to enable Fenton-like reaction and T1-weighted magnetic resonance (MR) imaging. We show that the MGPP-mediated GOx delivery facilitates enhanced chemodynamic/starvation therapy of cancer cells in vitro, and further codelivery of cGAMP can effectively trigger immunogenic cell death (ICD) to strongly promote the maturation of dendritic cells. In a bilateral mouse colorectal tumor model, the dendrimer delivery nanosystem elicits a potent antitumor performance with a strong abscopal effect, greatly improving the overall mouse survival rate. Importantly, the dendrimer-mediated codelivery not only allows the coordination of Mn2+ with GOx and cGAMP for respective chemodynamic/starvation-triggered ICD and augmented STING activation to boost systemic antitumor immune responses, but also enables T1-weighted tumor MR imaging, potentially serving as a promising nanoplatform for enhanced antitumor therapy with desired immune responses.

Enzyme-responsive nanospheres target senescent cells for diabetic wound healing by employing chemodynamic therapy

Evidence indicates that prolonged low-level inflammation and elevated-glucose-induced oxidative stress in diabetic wounds can accelerate senescence. The accumulation of senescent cells, in turn, inhibits cellular proliferation and migration, aggravating the inflammatory response and oxidative stress, ultimately impeding wound healing. In this study, we exploited the heightened lysosomal β-galactosidase activity detected in senescent cells to develop an innovative drug delivery system by encapsulating Fe3O4 with galactose-modified poly (lactic-co-glycolic acid) (PLGA) (F@GP). We found that F@GP can selectively release Fe3O4 into senescent cells, inducing ferroptosis via the Fenton reaction in the presence of elevated intracellular H2O2 levels. This showed that F@GP administration can serve as a chemodynamic therapy to eliminate senescent cells and promote cell proliferation. Furthermore, the F@GP drug delivery system gradually released iron ions into the diabetic wound tissues, enhancing the attenuation of cellular senescence, stimulating cell proliferation, promoting re-epithelialization, and accelerating the healing of diabetic wounds in mice. Our groundbreaking approach unveiled the specific targeting of senescence by F@GP, demonstrating its profound effect on promoting the healing of diabetic wounds. This discovery underscores the therapeutic potential of F@GP in effectively addressing challenging cases of wound repair. STATEMENT OF SIGNIFICANCE: The development of galactose-modified PLGA nanoparticles loaded with Fe3O4 (F@GP) represents a significant therapeutic approach for the treatment of diabetic wounds. These nanoparticles exhibit remarkable potential in selectively targeting senescent cells, which accumulate in diabetic wound tissue, through an enzyme-responsive mechanism. By employing chemodynamic therapy, F@GP nanoparticles effectively eliminate senescent cells by releasing iron ions that mediate the Fenton reaction. This targeted approach holds great promise for promoting diabetic wound healing by selectively eliminating senescent cells, which play a crucial role in impairing the wound healing process. The innovative utilization of F@GP nanoparticles as a therapeutic intervention offers a novel and potentially transformative strategy for addressing the challenges associated with diabetic wound healing.

Emulsifying Lipiodol with pH-sensitive DOX@HmA nanoparticles for hepatocellular carcinoma TACE treatment eliminate metastasis

Lipiodol-based transcatheter arterial chemoembolization (TACE) is currently the predominant and first-line treatment option recommended by the global standard for unresectable hepatocellular carcinoma (HCC). However, the unstable emulsion of Lipiodol causes a substantial proportion of chemotherapy drugs to enter the circulation system, leading to poor accumulation in cancer tissues and unexpected side effects of chemotherapy drugs. Herein, we emulsified Lipiodol with a pH-sensitive drug delivery system assembled from hexahistidine and zinc ions (HmA) with a super-high loading capacity of doxorubicin (DOX) and a promising ability to penetrate bio-barriers for the effective treatment of HCC by TACE. In vitro tests showed that DOX@HmA was comparable to free DOX in killing HCC cells. Impressively, during the in vivo TACE treatment, the anti-tumor efficacy of DOX@HmA was significantly greater than that of free DOX, indicating that DOX@HmA increased the accumulation of DOX in tumor. Emulsifying Lipiodol with pH-sensitive DOX@HmA significantly inhibited cell regeneration and tumor angiogenesis and decreased the systemic side effects of chemotherapy, especially by suppressing pulmonary metastasis in liver VX2 tumors in rabbits by inhibiting epithelial-mesenchymal transition (EMT). Emulsifying tumor microenvironment-responsive drug delivery systems (DDSs) with Lipiodol could be a new strategy for clinical TACE chemotherapy with potentially enhanced HCC treatment.

Lactose-Functionalized Carbosilane Glycodendrimers Are Highly Potent Multivalent Ligands for Galectin-9 Binding: Increased Glycan Affinity to Galectins Correlates with Aggregation Behavior

Galectins, the glycan binding proteins, and their respective carbohydrate ligands represent a unique fundamental regulatory network modulating a plethora of biological processes. The advances in galectin-targeted therapy must be based on a deep understanding of the mechanism of ligand-protein recognition. Carbosilane dendrimers, the well-defined and finely tunable nanoscaffolds with low toxicity, are promising for multivalent carbohydrate ligand presentation to target galectin receptors. The study discloses a synthetic method for two types of lactose-functionalized carbosilane glycodendrimers (Lac-CS-DDMs). Furthermore, we report their outstanding, dendritic effect-driven affinity to tandem-type galectins, especially Gal-9. In the enzyme-linked immunosorbent assay, the affinity of the third-generation multivalent dendritic ligand bearing 32 lactose units to Gal-9 reached nanomolar values (IC50 = 970 nM), being a 1400-fold more effective inhibitor than monovalent lactose for this protein. This demonstrates a game-changing impact of multivalent presentation on the inhibitory effect of a ligand as simple as lactose. Moreover, using DLS hydrodynamic diameter measurements, we correlated the increased affinity of the glycodendrimer ligands to Gal-3 and Gal-8 but especially to Gal-9 with the formation of relatively uniform and stable galectin/Lac-CS-DDM aggregates.

Tumor selective self-assembled nanomicelles of carbohydrate-epothilone B conjugate for targeted chemotherapy

Epothilone B (Epo B) is a potent antitumor natural product with sub-nanomolar anti-proliferation action against several human cancer cells. However, poor selectivity to tumor cells and unacceptable therapeutic windows of Epo B and its analogs are the major obstacles to their development into clinical drugs. Herein, we present self-assembled nanomicelles based on an amphiphilic carbohydrate-Epo B conjugate that is inactive until converted to active Epo B within the tumor. Four Epo B-Rhamnose conjugates linked via two linkers containing a disulfide bond that is sensitive to GSH were synthesized. Conjugate 34 can self-assemble into nanomicelles with a high concentration of Rha on the surface, allowing for better tumor targeting. After internalization by cancer cells, the disulfide bond can be cleaved in the presence of high levels of GSH to release active Epo B, thereby exhibiting significant anticancer efficiency and selectivity in vitro and in vivo.

Synthesis, Characterization, and Anticancer Potency of Branched Poly (p-Hydroxy Styrene) Schiff-Bases

A significant issue in cancer biology is finding anticancer therapies that effectively kill cancer cells. Through the use of several aldehydes, Schiff bases based on branched poly (p-hydroxy styrene) are created. The branched polymer is first chloroacetylated, then aminated with 1,4-phenylenediamine, and finally, aldehydes are reacted with the aminated polymer to produce the Schiff base compounds. Through the utilization of FTIR, TGA, XRD, NMR, and elemental analysis, all synthesized Schiff-bases are identified and characterized. Further, the antineoplastic potential of all Schiff bases is evaluated against different cancer cell lines. The results gained from this study indicate that the Schiff base polymers have cytotoxic power against cancer cells depending on cancer cell type and this antiproliferation potency is dose-concentration dependent. Importantly, the prepared S1 Schiff-base polymer shows potent cytotoxicity and is able to trigger the apoptosis and reactive oxygen species (ROS) in MCF-7 cells. Further, it downregulates VEGFR protein expression. The Schiff base polymers would have extensive applications in the biological disciplines.

Drug Repurposing-Based Brain-Targeting Self-Assembly Nanoplatform Using Enhanced Ferroptosis against Glioblastoma

Glioblastoma (GBM), the most aggressive and lethal form of malignant brain tumor, is a therapeutic challenge due to the drug filtration capabilities of the blood-brain barrier (BBB). Interestingly, glioblastoma tends to resist apoptosis during chemotherapy, but is susceptible to ferroptosis. Developing therapies that can effectively target glioblastoma by crossing the BBB and evoke ferroptosis are, therefore, crucial for improving treatment outcomes. Herein, a versatile biomimetic nanoplatform, L-D-I/NPs, is designed that self-assembled by loading the antimalarial drug dihydroartemisinin (DHA) and the photosensitizer indocyanine green (ICG) onto lactoferrin (LF). This nanoplatform can selectively target glioblastoma by binding to low-density lipoprotein receptor-related protein-1 (LRP1) and crossing the BBB, thus inducing glioblastoma cell ferroptosis by boosting intracellular reactive oxygen species (ROS) accumulation and iron overload. In addition, L-D-I/NPs have demonstrated the ability to effectively suppress the progression of orthotopic glioblastoma and significantly prolong survival in a mouse glioblastoma model. This nanoplatform has facilitated the application of non-chemotherapeutic drugs in tumor treatment with minimal adverse effects, paving the way for highly efficient ferroptosis-based therapies for glioblastoma.

Dendritic polymer-functionalized nanomedicine potentiates immunotherapy via lethal energy crisis-induced PD-L1 degradation

The advent of immune checkpoint inhibitors ushers in a new era of anti-tumor immunity. However, current clinical anti-PD-L1 antibodies only interdict PD-L1 on the membrane, which cannot diminish the complex cancer-promoting effects of intracellular PD-L1. Therefore, directly reducing the PD-L1 abundance of cancer cells might be a potential PD-L1 inhibitory strategy to circumvent the issues of current anti-PD-L1 antibodies. Herein, we develop a dendritic polymer-functionalized nanomedicine with a potent cellular energy depletion effect on colon cancer cells. Treatment with the nanomedicine significantly promotes phosphorylation of AMPK, which in turn leads to PD-L1 degradation and eventual T cell activation. Meanwhile, the nanomedicine can potently induce immunogenic cell death (ICD) to enhance the anti-cancer immunity. Moreover, the combination of the nanomedicine with PD-1 blockade further enhances the activity of cytotoxic T lymphocytes, and dramatically inhibits tumor growth in vivo without distinct side effects. Overall, this study provides a promising nanoplatform to induce lethal energy crisis and ICD, and suppress PD-L1 expression, thus potentiating cancer immunotherapy.

Development of Catalytic Site-Selective C-H Oxidation

Direct C-H bond oxygenation is a strong and useful tool for the construction of oxygen functional groups. After Chen and White's pioneering works, various non-heme-type iron and manganese complexes were introduced, leading to strong development in this area. However, for this method to become a truly useful tool for synthetic organic chemistry, it is necessary to make further efforts to improve site-selectivity, and catalyst durability. Recently, we found that non-heme-type ruthenium complex cis-1 presents efficient catalysis in C(sp3 )-H oxygenation under acidic conditions. cis-1-catalysed C-H oxygenation can oxidize various substrates including highly complex natural compounds using hypervalent iodine reagents as a terminal oxidant. Moreover, the catalyst system can use almost stoichiometric water molecules as the oxygen source through reversible hydrolysis of PhI(OCOR)2 . It is a strong tool for producing isotopic-oxygen-labelled compounds. Moreover, the environmentally friendly hydrogen peroxide can be used as a terminal oxidant under acidic conditions.

The effect of electrostatic high pressure nebulization on the stability, activity and ex vivo distribution of ionic self-assembled nanomedicines

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is applied to treat unresectable peritoneal metastasis (PM), an advanced, end-stage disease with a poor prognosis. Electrostatic precipitation of the aerosol (ePIPAC) is aimed at improving the intraperitoneal (IP) drug distribution and tumor penetration. Also, the combination of nanoparticles (NPs) as drug delivery vehicles and IP aerosolization as administration method has been proposed as a promising tool to treat PM. There is currently limited knowledge on how electrostatic precipitation (ePIPAC) and high pressure nebulization (PIPAC) affects the performance of electrostatically formed complexes. Therefore, the stability, in vitro activity and ex vivo distribution and tissue penetration of negatively charged cisPt-pArg-HA NPs and positively charged siRNA-RNAiMAX NPs was evaluated following PIPAC and ePIPAC. Additionally, a multidirectional Medspray® nozzle was developed and compared with the currently used Capnopen® nozzle. For both NP types, PIPAC and ePIPAC did not negatively influence the in vitro activity, although limited aggregation of siRNA-RNAiMAX NPs was observed following nebulization with the Capnopen®. Importantly, ePIPAC was linked to a more uniform distribution and higher tissue penetration of the NPs aerosolized by both nozzles, independent on the NPs charge. Finally, compared to the Capnopen®, an increased NP deposition was observed at the top of the ex vivo model following aerosolization with the Medspray® nozzle, which indicates that this device possesses great potential for IP drug delivery purposes. STATEMENT OF SIGNIFICANCE: Aerosolized drug delivery in the peritoneal cavity holds great promise to treat peritoneal cancer. In addition, electrostatic precipitation of the aerosol to the peritoneal tissue is aimed at improving the drug distribution and tumor penetration. The combination of nanoparticles (NPs), which are nano-sized drug delivery vehicles, and aerosolization has been proposed as a promising tool to treat peritoneal cancer. However, there is currently limited knowledge on how electrostatic precipitation and aerosolization affect the performance of electrostatically formed NPs. Therefore, the stability, activity, distribution and penetration of negatively and positively charged NPs was evaluated after aerosolization and electrostatic precipitation. Additionally, to further optimize the local drug distribution, a multidirectional spray nozzle was developed and compared with the currently used nozzle.

Facile preparation of PEGylated polyethylenimine polymers as vaccine carriers with reduced cytotoxicity and enhanced Interleukin-2 (IL-2) production

Developing low-cost, easy-to-prepare, biocompatible and highly efficient vaccine carriers is a promising approach to realize practical cancer immunotherapy. In this study, through facile modification of mPEG5k-4-toluenesulfonate (mPEG5k-OTs) on PEI25k under mild conditions, a series of "stealth" mPEG5k-PEI25k polymers (PP1, PP2 and PP3) were prepared, their structures and physicochemical properties were characterized and theoretically analyzed. The polymers could bind/load ovalbumin (OVA) to form mPEG5k-PEI25k/OVA complexes as negatively charged nanoparticles with small hydrodynamic particle size (80-210 nm) and narrow size distribution. Compared to PEI25k/OVA, lower cytotoxicity could be achieved on mPEG5k-PEI25k/OVA complexes in dendritic cells (DCs). In DCs-RF 33.70 T-cells co-culture system, the mPEG5k-PEI25k/OVA complexes could bring about higher IL-2 production /secretion than that of PEI25k/OVA, notably, the optimum IL-2 secretion could reach 9.3-folds of the PEI25k/OVA under serum condition (10% FBS). Moreover, the cell biological features could be optimized by selecting suitable mPEG5k-grafting ratios and/or mPEG5k-PEI25k/OVA weight ratios. Intracellular imaging results showed that the mPEG5k-PEI25k(PP3)/Rhodamine-OVA complexes mainly localized inside lysosomes. Taken together, this work provided a facile method to prepare "stealth" PEGylated-PEI25k polymers with reduced cytotoxicity, promoted OVA cross-presentation efficiency and improved serum compatibility towards cancer immunotherapy.

Nano-enabled colorectal cancer therapy

Colorectal cancer (CRC), one of the most common and deadliest diseases worldwide, poses a great health threat and social burden. The clinical treatments of CRC encompassing surgery, chemotherapy, and radiotherapy are challenged with toxicity, therapy resistance, and recurrence. In the past two decades, targeted therapy and immunotherapy have greatly improved the therapeutic benefits of CRC patients but they still suffer from drug resistance and low response rates. Very recently, gut microbiota regulation has exhibited a great potential in preventing and treating CRC, as well as in modulating the efficacy and toxicity of chemotherapy and immunotherapy. In this review, we provide a cutting-edge summary of nanomedicine-based treatment in colorectal cancer, highlighting the recent progress of oral and systemic tumor-targeting and/or tumor-activatable drug delivery systems as well as novel therapeutic strategies against CRC, including nano-sensitizing immunotherapy, anti-inflammation, gut microbiota modulation therapy, etc. Finally, the recent endeavors to address therapy resistance, metastasis, and recurrence in CRC were discussed. We hope this review could offer insight into the design and development of nanomedicines for CRC and beyond.

ROS-responsive PEGylated ferrocene polymer nanoparticles with improved stability for tumor-selective chemotherapy and imaging

Ferrocene-based nanoparticles have garnered interest as reactive oxygen species (ROS)-responsive nanocarriers of anticancer drugs and imaging agents. However, their biomedical applications remain limited due to their poor physiological stability. PEGylation of nanocarriers improves their stability and biocompatibility. In this study, we aimed to develop novel PEG-ferrocene nanoparticles (PFNPs) with enhanced stability and ROS responsiveness for the delivery of paclitaxel (PTX) and imaging agents. PEGylation improved the stability of ferrocene nanoparticles, inhibiting their ROS-responsive destruction. Several PEG-ferrocene polymers containing different molar ratios of methacrylic acid and poly (ethylene glycol) methyl ether methacrylate was designed for optimization. ROS-responsive polymers with optimal monomer ratios were self-assembled into PFNPs with enhanced stability. The PFNPs distended, effectively releasing encapsulated PTX and imaging agents within 8 h in the presence of ROS. Furthermore, they remained stable, with no changes in their hydrodynamic diameters or polydispersity indexes after storage in an aqueous solution and biological buffer. The accumulation of PFNPs in a tumor model in vivo was 15-fold higher than a free dye. PTX-loaded PFNPs showed a substantial tumor-suppression effect, reducing tumor size to approximately 18% of that in the corresponding control group. These findings suggest a promising application of ROS-responsive PFNPs in tumor treatment as biocompatible nanocarriers of anticancer drugs and imaging agents.

Construction of CpG Delivery Nanoplatforms by Functionalized MoS2 Nanosheets for Boosting Antitumor Immunity in Head and Neck Squamous Cell Carcinoma

Despite the promising achievements of immune checkpoint blockade (ICB) therapy for tumor treatment, its therapeutic effect against solid tumors is limited due to the suppressed tumor immune microenvironment (TIME). Herein, a series of polyethyleneimine (Mw = 0.8k, PEI0.8k )-covered MoS2 nanosheets with different sizes and charge densities are synthesized, and the CpG, a toll-like receptor-9 agonist, is enveloped to construct nanoplatforms for the treatment of head and neck squamous cell carcinoma (HNSCC). It is proved that functionalized nanosheets with medium size display similar CpG loading capacity regardless of low or high PEI0.8k coverage owing to the flexibility and crimpability of 2D backbone. CpG-loaded nanosheets with medium size and low charge density (CpG@MM -PL ) could promote the maturation, antigen-presenting capacity, and proinflammatory cytokines generation of bone marrow-derived dendritic cells (DCs). Further analysis reveals that CpG@MM -PL effectively boosts the TIME of HNSCC in vivo including DC maturation and cytotoxic T lymphocyte infiltration. Most importantly, the combination of CpG@MM -PL and ICB agents anti-programmed death 1 hugely improves the tumor therapeutic effect, inspiring more attempts for cancer immunotherapy. In addition, this work uncovers a pivotal feature of the 2D sheet-like materials in nanomedicine development, which should be considered for the design of future nanosheet-based therapeutic nanoplatforms.

Reinforcing the immunogenic cell death to enhance cancer immunotherapy efficacy

Immunogenic cell death (ICD) has been a revolutionary modality in cancer treatment since it kills primary tumors and prevents recurrent malignancy simultaneously. ICD represents a particular form of cancer cell death accompanied by production of damage-associated molecular patterns (DAMPs) that can be recognized by pattern recognition receptors (PRRs), which enhances infiltration of effector T cells and potentiates antitumor immune responses. Various treatment methods can elicit ICD involving chemo- and radio-therapy, phototherapy and nanotechnology to efficiently convert dead cancer cells into vaccines and trigger the antigen-specific immune responses. Nevertheless, the efficacy of ICD-induced therapies is restrained due to low accumulation in the tumor sites and damage of normal tissues. Thus, researchers have been devoted to overcoming these problems with novel materials and strategies. In this review, current knowledge on different ICD modalities, various ICD inducers, development and application of novel ICD-inducing strategies are summarized. Moreover, the prospects and challenges are briefly outlined to provide reference for future design of novel immunotherapy based on ICD effect.

Advanced dendritic glucan-derived biomaterials: From molecular structure to versatile applications

There is considerable interest in the development of advanced biomaterials with improved or novel functionality for diversified applications. Dendritic glucans, such as phytoglycogen and glycogen, are abundant biomaterials with highly branched three-dimensional globular architectures, which endow them with unique structural and functional attributes, including small size, large specific surface area, high water solubility, low viscosity, high water retention, and the availability of numerous modifiable surface groups. Dendritic glucans can be synthesized by in vivo biocatalysis reactions using glucosyl-1-phosphate as a substrate, which can be obtained from plant, animal, or microbial sources. They can also be synthesized by in vitro methods using sucrose or starch as a substrate, which may be more suitable for large-scale industrial production. The large numbers of hydroxyl groups on the surfaces of dendritic glucan provide a platform for diverse derivatizations, including nonreducing end, hydroxyl functionalization, molecular degradation, and conjugation modifications. Due to their unique physicochemical and functional attributes, dendritic glucans have been widely applied in the food, pharmaceutical, biomedical, cosmetic, and chemical industries. For instance, they have been used as delivery systems, adsorbents, tissue engineering scaffolds, biosensors, and bioelectronic components. This article reviews progress in the design, synthesis, and application of dendritic glucans over the past several decades.

Actinide Ion (Americium-241 and Uranium-232) Interaction with Hybrid Silica-Hyperbranched Poly(ethylene imine) Nanoparticles and Xerogels

The binding of actinide ions (Am(III) and U(VI)) in aqueous solutions by hybrid silica-hyperbranched poly(ethylene imine) nanoparticles (NPs) and xerogels (XGs) has been studied by means of batch experiments at different pH values (4, 7, and 9) under ambient atmospheric conditions. Both materials present relatively high removal efficiency at pH 4 and pH 7 (>70%) for Am(III) and U(VI). The lower removal efficiency for the nanoparticles is basically associated with the compact structure of the nanoparticles and the lower permeability and access to active amine groups compared to xerogels, and the negative charge of the radionuclide species is formed under alkaline conditions (e.g., UO2(CO3)34- and Am(CO3)2-). Generally, the adsorption process is relatively slow due to the very low radionuclide concentrations used in the study and is basically governed by the actinide diffusion from the aqueous phase to the solid surface. On the other hand, adsorption is favored with increasing temperature, assuming that the reaction is endothermic and entropy-driven, which is associated with increasing randomness at the solid-liquid interphase upon actinide adsorption. To the best of our knowledge, this is the first study on hybrid silica-hyperbranched poly(ethylene imine) nanoparticle and xerogel materials used as adsorbents for americium and uranium at ultra-trace levels. Compared to other adsorbent materials used for binding americium and uranium ions, both materials show far higher binding efficiency. Xerogels could remove both actinides even from seawater by almost 90%, whereas nanoparticles could remove uranium by 80% and americium by 70%. The above, along with their simple derivatization to increase the selectivity towards a specific radionuclide and their easy processing to be included in separation technologies, could make these materials attractive candidates for the treatment of radionuclide/actinide-contaminated water.