Tumor microenvironment triggered local oxygen generation and photosensitizer release from manganese dioxide mineralized albumin-ICG nanocomplex to amplify photodynamic immunotherapy efficacy

Multifunctional PLGA nanocomposites to improve beta cell replacement therapy in Type 1 diabetes

Diabetes Mellitus is a rapidly growing global health problem, with its prevalence having risen sharply in recent years. Type 1 diabetes (T1D) treatment options are limited, with most of them significantly compromising the quality of life of these patients. This study presents the development and characterization of a multifunctional hybrid nanoformulation (mHNFs) designed to enhance the efficacy of beta cell replacement therapy in T1D. By encapsulating rapamycin and two types of magnetic nanoparticles (MnO and Fe3O4) within PLGA, we aimed to address critical challenges in islet transplantation, including hypoxia and immunosuppression. The synthesized nanoparticles demonstrated dual imaging capabilities as MRI contrast agents, sustained drug release, and in situ oxygen generation, crucial for mitigating islet hypoxia and loss of function. In vitro studies confirmed the cytocompatibility of the system and its efficient internalization by rin-m cells. Additionally, O2 generation studies proved that mHNFs significantly reduced hypoxia levels. These results highlight the potential of these nanocarriers to improve the safety and efficacy of T1D islet transplantation treatments through a multifunctional approach.

Revolutionizing anticoagulation: Nanoengineered therapies and precision medicine approaches

With the advancement of therapeutic concepts, early intervention with antithrombotic therapy for patients at potential thrombotic risk is becoming more proactive. Anticoagulant therapy, a critical component of antithrombotic treatment, thus plays a key role in the prevention and treatment of cardiovascular diseases. Unfortunately, existing anticoagulation treatments still face many challenges, including abnormal bleeding, allergic reactions, and drug resistance. To identify novel technologies for addressing these issues and explore the latest research developments in the field of anticoagulation, this paper reviewed the advances of anticoagulant factor-loaded nanoplatforms firstly. These systems can precisely deliver anticoagulant drugs to specific targets, improving drug bioavailability and reducing unnecessary systemic side effects. Subsequently, the paper delved into the development of anticoagulant technologies, including the advancements in biocompatible anticoagulant nanomaterials, the application of DNA origami technology, and the progress in external energy-mediated anticoagulation strategies. A common feature of these engineered anticoagulation systems is their ability to modulate the dynamic balance of anticoagulant factors in the body without relying on traditional drugs, enabling more personalized and efficient anticoagulation effects. Finally, the paper examined novel precision anticoagulation strategies that combine biomedical engineering technologies with precision anticoagulation therapy. These strategies can tailor anticoagulation treatments to the specific pathological conditions of individual patients, such as thrombin activity, thereby reducing the risk of excessive anticoagulation. In conclusion, the engineered anticoagulation therapy strategies proposed in this paper represent cutting-edge advancements in anticoagulation medicine, providing more precise and safer solutions for the treatment of thrombotic diseases, and offering important theoretical and practical guidance for future personalized medicine and precision therapies.

Tumor-Targeted Metal-Organic Framework for Improved Photodynamic Therapy and Inhibited Tumor Metastasis in Melanoma

Tumor hypoxia and elevated intracellular glutathione (GSH) levels significantly compromise the effectiveness of photodynamic therapy (PDT) in treating melanoma. In this study, we synthesized positively charged nanoparticles through a self-assembly method, incorporating photosensitizer verteporfin (VER), mitochondrial respiratory inhibitor atovaquone (ATO), and Fe3+. Subsequently, the nanoparticles were modified with sodium hyaluronate (HA) to obtain HA-ATO-Fe3+-VER nanoparticles (HAFV NPs). The fabricated HAFV NPs demonstrated excellent stability and in vitro Fenton reaction activity. HA facilitated the cellular internalization of HAFV NPs by targeting CD44 receptors, hence relieving tumor hypoxia through the disruption of the mitochondrial respiratory chain and involvement in the Fenton reaction. Simultaneously, ATO directly impeded the biosynthesis of GSH by diminishing ATP levels, while Fe3+ was supposed to oxidate GSH to GSSG, thereby doubly depleting GSH. The integration of these multiple mechanisms markedly enhanced the PDT efficacy of VER. Following intravenous administration, HAFV NPs preferentially accumulated in tumor tissues with minimal accumulation in the skin, demonstrating favorable biocompatibility in vivo. Furthermore, HAFV NPs effectively inhibited tumor growth and lung metastasis, which presents a promising strategy for melanoma treatment.

Polymeric nanocarrier via metabolism regulation mediates immunogenic cell death with spatiotemporal orchestration for cancer immunotherapy

The limited efficacy of cancer immunotherapy occurs due to the lack of spatiotemporal orchestration of adaptive immune response stimulation and immunosuppressive tumor microenvironment modulation. Herein, we report a nanoplatform fabricated using a pH-sensitive triblock copolymer synthesized by reversible addition-fragmentation chain transfer polymerization enabling in situ tumor vaccination and tumor-associated macrophages (TAMs) polarization. The nanocarrier itself can induce melanoma immunogenic cell death (ICD) via tertiary amines and thioethers concentrating on mitochondria to regulate metabolism in triggering endoplasmic reticulum stress and upregulating gasdermin D for pyroptosis as well as some features of ferroptosis and apoptosis. After the addition of ligand cyclic arginine-glycine-aspartic acid (cRGD) and mannose, the mixed nanocarrier with immune adjuvant resiquimod encapsulation can target B16F10 cells for in situ tumor vaccination and TAMs for M1 phenotype polarization. In vivo studies indicate that the mixed targeting nanoplatform elicits tumor ICD, dendritic cell maturation, TAM polarization, and cytotoxic T lymphocyte infiltration and inhibits melanoma volume growth. In combination with immune checkpoint blockade, the survival time of mice is markedly prolonged. This study provides a strategy for utilizing immunoactive materials in the innate and adaptive immune responses to augment cancer therapy.

Photothermal-Enhanced Dual Inhibition of Lactate/Kynurenine Metabolism for Promoting Tumor Immunotherapy

Traditionally referred to as "metabolic junk", lactate has now been recognized as essential "energy currency" and crucial "messenger" that contributes to tumor evolution, immunosuppression, etc., thus presenting a promising strategy for antitumor interventions. Similarly, kynurenine (Kyn) also exerts an immunosuppressive function, thereby significantly compromising the effectiveness of immunotherapy. This study proposes and validates a strategy for enhancing immunotherapy through photothermal-assisted depletion of lactate sustained by cycle-like O2 supply, with blocking the tryptophan (Trp)/Kyn metabolic pathway. In brief, a nanozyme therapeutic agent (PNDPL) is constructed, which mainly consists of PtBi nanozymes, lactate oxidase (LOX) and the indoleamine 2,3-dioxygenase (IDO) inhibitor NLG919. The PtBi nanozymes, which exhibit a catalase (CAT)-like activity, form a positive feedback loop with LOX to consume lactate while self-supplying O2 . Moreover, PtBi nanozymes retain enzyme-like performance even in a slightly acidic tumor microenvironment. Under 1064 nm irradiation, photothermal therapy (PTT) not only induces tumor cell death but also accelerates lactate exhaustion. Therefore, the combination of lactate depletion-induced starvation therapy and PTT, along with the blocking of IDO-mediated immune escape, effectively inhibits tumor growth and reverses immunosuppressive microenvironment, thus preventing tumor metastasis. This study represents the first investigation into the synergistic antitumor effects by lactate metabolism regulation and IDO-related immunotherapy.

Biomaterial-Based Responsive Nanomedicines for Targeting Solid Tumor Microenvironments

Solid tumors are composed of a highly complex and heterogenic microenvironment, with increasing metabolic status. This environment plays a crucial role in the clinical therapeutic outcome of conventional treatments and innovative antitumor nanomedicines. Scientists have devoted great efforts to conquering the challenges of the tumor microenvironment (TME), in respect of effective drug accumulation and activity at the tumor site. The main focus is to overcome the obstacles of abnormal vasculature, dense stroma, extracellular matrix, hypoxia, and pH gradient acidosis. In this endeavor, nanomedicines that are targeting distinct features of TME have flourished; these aim to increase site specificity and achieve deep tumor penetration. Recently, research efforts have focused on the immune reprograming of TME in order to promote suppression of cancer stem cells and prevention of metastasis. Thereby, several nanomedicine therapeutics which have shown promise in preclinical studies have entered clinical trials or are already in clinical practice. Various novel strategies were employed in preclinical studies and clinical trials. Among them, nanomedicines based on biomaterials show great promise in improving the therapeutic efficacy, reducing side effects, and promoting synergistic activity for TME responsive targeting. In this review, we focused on the targeting mechanisms of nanomedicines in response to the microenvironment of solid tumors. We describe responsive nanomedicines which take advantage of biomaterials' properties to exploit the features of TME or overcome the obstacles posed by TME. The development of such systems has significantly advanced the application of biomaterials in combinational therapies and in immunotherapies for improved anticancer effectiveness.

Design of manganese-based nanomaterials for pharmaceutical and biomedical applications

In the past few years, manganese-based nanostructures have been extensively investigated in the biomedical field particularly to design highly biocompatible theranostics, which can not only act as efficient diagnostic imaging contrast agents but also deliver the drugs to the target sites. The nanoscale size, large surface area-to-volume ratio, availability of cheap precursors, flexibility to synthesize nanostructures with reproducible properties and high yield, and easy scale up are the major reasons for the attraction towards manganese nanostructures. Along with these properties, the nontoxic nature, pH-sensitive degradation, and easy surface functionalization are additional benefits for the use of manganese nanostructures in biomedical and pharmaceutical sciences. Therefore, in this review, we discuss the recent progress made in the synthesis of manganese nanostructures, describe the attempts made to modify their surfaces to impart biocompatibility and stability in biological fluids, and critically discuss their use in magnetic resonance imaging, drug and gene delivery, hyperthermia, photothermal/photodynamic, immunotherapy, biosensing and tumor diagnosis.

Dual effect of light and ultrasound for efficient singlet oxygen generation with novel diaxial silicon phthalocyanine sensitizer

To treat a life-threatening disease like cancer, photodynamic therapy (PDT) and sonodynamic therapy (SDT) methods were combined into sono-photodynamic therapy (SPDT) as an effective therapeutic solution. Each day, the usage of phthalocyanine sensitizers increases in the therapeutic applications as they have the ability to produce more reactive oxygen species. In this context, a new diaxially silicon phthalocyanine sensitizer, containing triazole and tert-butyl groups, was synthesized. After elucidating the structure of the complex with elemental analysis, FT-IR, UV-Vis, MALDI-TOF MS and 1 H NMR, its photophysical, photochemical and sono-photochemical properties were examined. When singlet oxygen generation capacity of the new synthesized silicon phthalocyanine complex was determined and compared among photochemical (PDT; ФΔ  = 0.59 in DMSO, 0.44 in THF, 0.47 in toluene) and sonophotochemical (SPDT; ФΔ  = 0.88 in dimethyl sulfoxide (DMSO), 0.60 in tetrahydrofuran (THF), 0.65 in toluene) methods, it can be said that the complex is a successful sono-photosensitizer that can be used as a good SPDT agent in vitro or in vivo future studies.

A nanoparticle composed of totally hospital-available drugs and isotope for fluorescence/SPECT dual-modal imaging-guided photothermal therapy to inhibit tumor metastasis

As primary sites of tumor metastasis, sentinel lymph nodes (SLNs) require a highly biocompatible theranostic platform for precise localization and treatment to inhibit tumor metastasis. Herein, indocyanine green-human serum albumin (ICG-HSA) nanoparticles (NPs) were fabricated by ICG-induced self-assembly and radiolabeled with technetuim-99 m (99mTc). The fabricated NPs were composed of hospital-available drugs and isotopes, making them highly biocompatible for in vivo applications. In a mouse model of SLN metastasis, the prepared NPs exhibited excellent capacity for preoperative planning by single-photon emission computed tomography (SPECT) imaging-enabled SLN localization, near-infrared fluorescence (NIRF) imaging-enabled intraoperative real-time monitoring, and SLN photothermal treatment. Photothermal treatment with SLN enhanced the inhibition of lung metastasis and significantly increased the survival time of mice. The prepared NPs were highly biocompatible and exhibited efficient theranostic properties for inhibiting cancer metastasis, making them promising candidates for clinical translation.

The GSH responsive indocyanine green loaded PD-1 inhibitory polypeptide AUNP12 modified MOF nanoparticles for photothermal and immunotherapy of melanoma

Introduction: Photothermal therapy (PTT) holds significant potential for the treatment of malignant tumors. However, conventional single PTT often struggles to effectively inhibit tumor metastasis and recurrence. In this study, we constructed a MOF nanoparticle with a synergistic therapeutic effect combining photothermal and immunotherapy, enabling selective blocking of the PD-1/PD-L1 pathway within the tumor microenvironment. Methods: Firstly, MOF nanoparticles were synthesized using NH2-TPDC as ligands and Zr+4 as metal ions. Subsequently, NH2 was modified to N3 via azide transfer reagents. Through a copper free catalytic click chemical reaction, the PD-1/PD-L1 blocking agent AUNP-12 functionalized with disulfide bonds of DBCO was covalently introduced into MOF nanoparticles which were then loaded with the photothermal agent indocyanine green (ICG) to successfully obtain uniformly sized and stable ICG-MOF-SS-AUNP12 nanoparticles. Results and discussion: ICG-MOF-SS-AUNP12 exhibited GSH-triggered release of PD-1/PD-L1 blockers while demonstrating potent photothermal effects capable of efficiently killing tumor cells. Under 808 nm near-infrared (NIR) irradiation, ICG-MOF-SS-AUNP12 effectively promoted the maturation of DC cells and activated immune responses. This study presents a novel method for constructing MOF-based nanodrugs and offers new possibilities for the synergistic treatment of tumors involving photothermal combined with immunotherapy.

Multifunctional protein-based self-assembled nanoplatform: overcoming hypoxic tumor microenvironment for enhanced imaging-guided photodynamic therapy

Photodynamic therapy (PDT) has emerged as a promising modality for cancer treatment, but its efficacy is often limited by tumour hypoxia. Here, we report the development of a novel protein-based, self-assembled nanoplatform, CAT-I-BODIPY NPs (CIB NPs), to address this limitation. We first design and synthesize an I-BODIPY photosensitizer based on the heavy atom effect and modification of the electron-donating group, which exhibits excellent capabilities in generating reactive oxygen species and enabling near-infrared (NIR) fluorescence imaging. The incorporation of an oxygen-producing enzyme, catalase (CAT), within these nanoassemblies enables in situ oxygen generation to counteract hypoxic constraints. Controllable self-assembly by multiple supramolecular interactions into highly ordered architecture not only guarantees CAT's catalytic activity but also leads to excellent NIR fluorescence imaging ability and enhanced PDT efficacy. Notably, the visualization of optimal accumulation of CIB NPs within tumour sites 18 h post-injection offers precise PDT application guidance. Both in vitro and in vivo studies corroborate the remarkable anti-tumour efficacy of CIB NPs under NIR illumination, providing a significant advancement in PDT. The favourable biosafety profile of CIB NPs further emphasizes their potential for clinical application in hypoxic tumour therapy.

Controllable Regulation of Ag2 S Quantum-Dot-Mediated Protein Nanoassemblies for Imaging-Guided Synergistic PDT/PTT/Chemotherapy against Hypoxic Tumor

The combination of phototherapy and chemotherapy holds great potential for cancer treatment, while hypoxia in tumor as well as unexpected drug release largely restricts anticancer therapy. Inspired by the natural intelligence, herein, for the first time, a "bottom-up" protein self-assembly strategy mediated by near-infrared (NIR) quantum dots (QDs) with multicharged electrostatic interactions is presented to develop a tumor microenvironment (TME)-responsive theranostic nanoplatform for imaging-guided synergistic photodynamic therapy (PDT)/photothermal therapy (PTT)/chemotherapy. Catalase (CAT) possesses diverse surface charge distribution under different pH conditions. After modification by chlorin e6 (Ce6), the formulated CAT-Ce6 with patchy negative charges can be assembled with NIR Ag2 S QDs by regulating their electrostatic interactions, allowing for effective incorporation of specific anticancer drug oxaliplatin (Oxa). Such Ag2 S@CAT-Ce6@Oxa nanosystems are able to visualize nanoparticle (NP) accumulation to guide subsequent phototherapy, together with significant alleviation of tumor hypoxia to further enhance PDT. Moreover, the acidic TME triggers controllable disassembly through weakening the CAT surface charge to disrupt electrostatic interactions, allowing for sustained drug release. Both in vitro and in vivo results demonstrate remarkable inhibition of colorectal tumor growth with a synergistic effect. Overall, this multicharged electrostatic protein self-assembly strategy provides a versatile platform for realizing TME-specific theranostics with high efficiency and safety, promising for clinical translation.

Recent progress of metal-based nanomaterials with anti-tumor biological effects for enhanced cancer therapy

Metal-based nanomaterials have attracted broad attention recently due to their unique biological physical and chemical properties after entering tumor cells, namely biological effects. In particular, the abilities of Ca2+ to modulate T cell receptors activation, K+ to regulate stem cell differentiation, Mn2+ to activate the STING pathway, and Fe2+/3+ to induce tumor ferroptosis and enhance catalytic therapy, make the metal ions and metal-based nanomaterials play crucial roles in the cancer treatments. Therefore, due to the superior advantages of metal-based nanomaterials and the characteristics of the tumor microenvironment, we will summarize the recent progress of the anti-tumor biological effects of metal-based nanomaterials. Based on the different effects of metal-based nanomaterials on tumor cells, this review mainly focuses on the following five aspects: (1) metal-enhanced radiotherapy sensitization, (2) metal-enhanced catalytic therapy, (3) metal-enhanced ferroptosis, (4) metal-enhanced pyroptosis, and (5) metal-enhanced immunotherapy. At the same time, the shortcomings of the biological effects of metal-based nanomaterials on tumor therapy are also discussed, and the future research directions have been prospected. The highlights of promising biosafety, potent efficacy on biological effects for tumor therapy, and the in-depth various biological effects mechanism studies of metal-based nanomaterials provide novel ideas for the future biological application of the nanomaterials.

Glycyrrhizic Acid-Lipid Framework Nanovehicle Loading Triptolide for Combined Immunochemotherapy

Despite the acknowledged advantages of combined immunochemotherapy for tumor treatment, the high efficiency of co-delivery of these combined agents into the targeted tumor tissue is still challenging. Herein, based on a "three-birds-with-one-stone" strategy, a facile glycyrrhizic acid (GL)-lipid hybrid nanoplatform loading triptolide (TP/GLLNP) is designed to better address the dilemma. Differing from the traditional liposomes with dual-drug co-delivery NPs, GL with a cholesterol-like structure is primarily employed to construct the lipid membrane skeleton of the GL-based lipid nanoparticle (GLLNP), and then triptolide (TP) is readily loaded in the lipid bilayer of GLLNP. The fabricated GLLNP possessed similar drug loading efficacy, particle size, and storage stability; none of the hemolysis; even higher membrane fluidity; and lower absorbed opsonin proteins compared with the conventional liposomes. Compared to TP-loaded traditional liposomes (TP/Lipo), TP/GLLNP exhibits significantly enhanced cellular uptake, cytotoxicity, and apoptosis of HepG2 cells. In addition, GLLNP could ameliorate tumor immunosuppression by promoting tumor-associated macrophage polarization from M2 to M1 phenotype. Furthermore, enhanced retention and accumulation in the tumor area of GLLNP could be found. As expected, TP/GLLNP displayed synergistic anti-hepatocellular carcinoma efficacy in vivo. In conclusion, this study provides an inspirational strategy to combine the anti-HCC benefits of GL and TP using a novel dual-drug co-delivery nanosystem.

Research Progress in Oxygen Carrier Design and Application

Ischemia or hypoxia can lead to pathological changes in the metabolism and function of tissues and then lead to various diseases. Timely and effective blood resuscitation or improvement of hypoxia is very important for the treatment of diseases. However, there is a need to develop stable, nontoxic, and immunologically inert oxygen carriers due to limitations such as blood shortages, different blood types, and the risk of transmitting infections. With the development of various technologies, oxygen carriers based on hemoglobin and perfluorocarbon have been widely studied in recent years. This paper reviews the development and application of hemoglobin and perfluorocarbon oxygen carriers. The design of oxygen carriers was analyzed, and their application as blood substitutes or oxygen carriers in various hypoxic diseases was discussed. Finally, the characteristics and future research of ideal oxygen carriers were prospected to provide reference for follow-up research.

Self-driven nanoprodrug platform with enhanced ferroptosis for synergistic photothermal-IDO immunotherapy

Insufficient immune stimulation and stubborn immune resistance are the critical factors limiting tumor immunotherapy. Here, we report a multifunctional nanoprodrug platform with self-driven indoximod (IND) release and oxidative stress amplification. The aim is to awaken immune responses and block the indoleamine 2,3-dioxygenase (IDO) pathway through a combination of ferroptosis, photothermal therapy, and immunotherapy. This nanosystem improved the delivery efficiency of IND due to click chemistry linked ROS responsive prodrug and self-driven drug release. Meanwhile, the tactic of simultaneously increasing ROS and eliminating GSH amplified oxidative stress and strengthened ferroptosis, which further enhanced immunogenicity along with polydopamine-based photothermal therapy. IDO immunization combined with ferroptosis as well as photothermal therapy not only stimulated immune response, but also reversed immune suppression with enhanced immune memory. Therefore, primary tumor, distant tumor, and cancer metastasis were inhibited. This study provides a perspective on immunotherapeutics for cancer treatment.

Ultrasound Triggered Tumor Metabolism Suppressor Induces Tumor Starvation for Enhanced Sonodynamic Immunotherapy of Breast Cancer

Introduction

Sonodynamic therapy (SDT) as an emerging tumor treatment gained wide attention. However, tumor vascular destruction and oxygen depletion in SDT process may lead to further hypoxia. This may lead to enhanced glycolysis, lactate accumulation, and immunosuppression.

Methods

A glycolysis inhibitor (3PO) loaded and PEG modified black phosphorus nanosheets (BO) is constructed for potent starvation therapy and efficient immune activation.

Results

Under ultrasound irradiation, the BO can produce ROS to destroy tumors and tumor blood vessels and lead to further hypoxia and nutrients block. Then, the released 3PO inhibits tumor glycolysis and prevents the hypoxia-induced glycolysis and lactate accumulation. Both SDT and 3PO can cut off the source of lactic acid, as well as achieve antitumor starvation therapy through the blockade of the adenosine triphosphate (ATP) supply. In addition, the combination of starvation treatment and SDT further facilitates dendritic cells (DC) maturation, promotes antigen presentation by DCs, and eventually propagates the antitumor immunity and inhibition of abscopal tumor growth.

Conclusion

This is the first time that combines SDT with inhibition of glycolysis, achieving admirable tumor treatment and decreasing adverse events caused by SDT process and that has caused good immune activation. Our system provides a new idea for the future design of anti-tumor nanomedicines.

Gold Nanorods and Polymer Micelles Mediated Dual TLR Stimulators Delivery System CPG@Au NRs/M-R848 Regulate Macrophages Reprogramming and DC Maturation for Enhanced Photothermal Immunotherapy of Melanoma

Synergistic photothermal immunotherapy has emerged as a favorable therapeutic approach to fight cancer. However, design of an effective photothermal immunotherapy system to suppress tumor growth and simultaneously inhibit tumor metastases continues to be a challenge. Here a dual toll-like receptor agonists delivery system CPG@Au NRs/m-R848 for combined photothermal immunotherapy of melanoma is developed. CPG@Au NRs/m-R848 displays strong antitumor effects by promoting maturation of dendritic cells (DCs) and reprogramming of M2 macrophages into M1 phenotype. Moreover, immunogenic cell death (ICD) induced by photothermal ablation of Au NRs could synergistically produce in situ vaccination effect with CPG ODN and R848, generating systemic and lasting antitumor immunity. It is further proved that CPG@Au NRs/m-R848 treatment inhibits tumor growth in bilateral B16F10 tumors model by eliciting CD8+ T cell response. Overall, this work suggests that this strategy hold great potential in tumor immunotherapy by regulating tumor-associated macrophage polarization, triggering DCs maturation and inducing ICD.

A type I AIE photosensitiser-loaded biomimetic nanosystem allowing precise depletion of cancer stem cells and prevention of cancer recurrence after radiotherapy

Radioresistance of Cancer stem cell (CSC) is an important cause of tumor recurrence after radiotherapy (RT). Herein, we designed a type I aggregation-induced emission (AIE) photosensitiser-loaded biomimetic mesoporous organosilicon nanosystem (PMT) for precise depletion of CSC to prevent tumor recurrence after RT. This PMT system is composed of a type I AIE photosensitiser (TBP-2) loaded mesoporous organosilicon nanoparticles (MON) with an outer platelet membrane. The PMT system is able to specifically target CSC. Intracellular glutathione activity leads to MON degradation and the release of TBP-2. Type I photodynamic therapy is activated by exposure to white light, producing a large amount of hydroxyl radicals to promote CSC death. The results of in vivo experiments demonstrated specific removal of CSC following PMT treatment, with no tumor recurrence observed when combined with RT. However, tumor recurrence was observed in mice that received RT only. The expression of CSC markers was significantly reduced following PMT treatment. We demonstrate the development of a system for the precise removal of CSC with good biosafety and high potential for clinical translation. We believe the PMT nanosystem represents a novel idea in the prevention of tumor recurrence.

Reduction-Hypersensitive Podophyllotoxin Prodrug Self-Assembled Nanoparticles for Cancer Treatment

Podophyllotoxin (PPT) has shown strong antitumor effects on various types of cancers. However, the non-specific toxicity and poor solubility severely limits its clinical transformation. In order to overcome the adverse properties of PPT and explore its clinical potential, three novel PTT-fluorene methanol prodrugs linked by different lengths of disulfide bonds were designed and synthesized. Interestingly, the lengths of the disulfide bond affected the drug release, cytotoxicity, pharmacokinetic characteristics, in vivo biodistribution and antitumor efficacy of prodrug NPs. To be more specific, all three PPT prodrugs could self-assemble into uniform nanoparticles (NPs) with high drug loading (>40%) via the one-step nano precipitation method, which not only avoids the use of surfactants and cosurfactants, but also reduces the systemic toxicity of PPT and increases the tolerated dose. Among the three prodrug NPs, FAP NPs containing α-disulfide bond showed the most sensitive tumor-specific response and fastest drug release rate, thus demonstrating the strongest in vitro cytotoxicity. In addition, three prodrug NPs showed prolonged blood circulation and higher tumor accumulation. Finally, FAP NPs demonstrated the strongest in vivo antitumor activity. Our work will advance the pace of podophyllotoxin towards clinical cancer treatment.

Mn3 O4 Nanoshell Coated Metal-Organic Frameworks with Microenvironment-Driven O2 Production and GSH Exhaustion Ability for Enhanced Chemodynamic and Photodynamic Cancer Therapies

Nanomedicine exhibits emerging potentials to deliver advanced therapeutic strategies in the fight against triple-negative breast cancer (TNBC). Nevertheless, it is still difficult to develop a precise codelivery system that integrates highly effective photosensitizers, low toxicity, and hydrophobicity. In this study, PCN-224 is selected as the carrier to enable effective cancer therapy through light-activated reactive oxygen species (ROS) formation, and the PCN-224@Mn₃ O₄ @HA is created in a simple one-step process by coating Mn₃ O₄ nanoshells on the PCN-224 template, which can then be used as an "ROS activator" to exert catalase- and glutathione peroxidase-like activities to alleviate tumor hypoxia while reducing tumor reducibility, leading to improved photodynamic therapeutic (PDT) effect of PCN-224. Meanwhile, Mn²⁺ produced cytotoxic hydroxyl radicals (∙OH) via the Fenton-like reaction, thus producing a promising spontaneous chemodynamic therapeutic (CDT) effect. Importantly, by remodeling the tumor microenvironment (TME), Mn₃ O₄ nanoshells downregulated hypoxia-inducible factor 1α expression, inhibiting tumor growth and preventing tumor revival. Thus, the developed nanoshells, via light-controlled ROS formation and multimodality imaging abilities, can effectively inhibit tumor proliferation through synergistic PDT/CDT, and prevent tumor resurgence by remodeling TME.

Smart Phototheranostics based on Carbon Nanohorns for Precise Imaging-Guided Post-PDT toward Residual Tumor Cells after Initial Phototherapy

As promising photonic material, phototheranostics can be activated in the laser irradiation range of tumor with sensitivity and spatiotemporal precision. However, it is difficult to completely eradicate solid tumors due to their irregularity and limited laser irradiation area. Herein, multi-stimulus responsive HA-Ce6@SWNHs were constructed with single-walled carbon nanohorns (SWNHs) and chlorine e6 (Ce6) modified hyaluronic acid (HA) via non-covalent binding. This SWNHs-based phototheranostics not only exhibited water dispersion but also could target tumor and be activated by near-infrared light for photodynamic therapy (PDT) and photothermal therapy (PTT). Additionally, HA-Ce6@SWNHs could be degraded by hyaluronidase in residual tumor cells, causing HA-Ce6 to fall off the SWNHs surfaces to restore autofluorescence, thus precisely guiding the programmed photodynamic treatments for residual tumor cells after the initial phototherapy. Thus, this work provides a rationally designed multiple-stimulus-response strategy to develop smart SWNHs-based phototheranostics for precise PDT/PTT and post-treatment imaging-guided PDT of residual tumor cells.

Epigenetic reprogramming of carrier free photodynamic modulator to activate tumor immunotherapy by EZH2 inhibition

Tumor cells are characterized by unlimited proliferation and escape of immune clearance, which are closely associated with the down regulation of surface antigens. In this work, a carrier free photodynamic modulator (CeTaz) is developed to improve immunosuppressive tumor microenvironment and promote the recognition of tumors by T cells by epigenetic reprogramming. Specifically, CeTaz is assembled by chlorine e6 (Ce6) and tazemetostat (Taz) through intermolecular interactions. Upon light irradiation, CeTaz is able to promote the generation of reactive oxygen species (ROS) for a robust photodynamic therapy (PDT) to inhibit localized tumor growth. Meanwhile, the PDT also induces immunogenic cell death (ICD) to initiate immune response, leading to the activation of effector T cells. More importantly, CeTaz could inhibit the epigenetic regulator of EZH2 to suppress the methylation of H3K27, which would promote tumor cells to express MHC-I and release CXCL10. Consequently, the epigenetically reprogrammed tumor cells are readily recognized by effector T cells to enhance the antitumor immunity. Results indicate that the PDT activated immunotherapy of CeTaz could simultaneously inhibit the growth of primary and distant tumors with a low system toxicity. This study would advance the development of carrier free nanomedicine for precise treatment of metastatic tumor.

PROTAC Nanoplatform with Targeted Degradation of NAD(P)H:Quinone Oxidoreductase 1 to Enhance Reactive Oxygen Species-Mediated Apoptosis

Apoptosis mediated by reactive oxygen species (ROS) has emerged as a promising therapeutic strategy for tumors. However, the overexpression of NAD(P)H:quinone oxidoreductase 1 (NQO1) protein restricted ROS production through a negative feedback pathway in tumor cells, promoting tumor progression, and weakening the effect of drug therapy. Here, a PROTACs nanodrug delivery system (PN) was constructed to increase ROS generation by degrading the NQO1 protein. Specifically, a PROTAC (proteolytic targeting chimera) molecule DQ was designed and synthesized. Then DQ and withaferin A (WA, an inducer of ROS) were loaded into PNs. DQ degraded the overexpressed NQO1 protein in tumor cells through a protein ubiquitination degradation pathway, thereby weakening the antioxidant capacity of tumor cells. Meanwhile, the reduction of NQO1 could inhibit the negative feedback effect of ROS production, thus increasing ROS generation. It has been demonstrated that PNs can significantly increase ROS production and possess potent antitumor properties in vitro and in vivo. This nanoplatform may offer an alternative approach to treating tumors with NQO1 overexpression.

Anticancer Effect of Chlorambucil Enhanced by Chiral Phthalidyl Promoiety

Phthalidyl promoiety has been used in several drugs, but they were all marketed in racemic form. The pharmaceutical effects of each enantiomer have not been clearly demonstrated. In this project, an anticancer chemotherapy drug, chlorambucil, was modified as enantiopure phthalidyl prodrugs. The enantiomers, together with phthalidyl unit and their racemic mixture, were then subject to the in vivo bioactivity tests against B16F10 melanoma cells. It was found that proper chirality within the promoiety had noticeably better in vivo pharmacological effects than the parent drug, the enantiomer and racemic mixture. This merit perhaps could be extended from the phthalidyl prodrugs to other chirality containing prodrugs.

Short-Wavelength Aggregation-Induced Emission Photosensitizers for Solid Tumor Therapy: Enhanced with White-Light Fiber Optic

Background

White-light photodynamic therapy (wPDT) has been used in the treatment of cancer due to its convenience, effectiveness and less painful. However, the limited penetration of white-light into the tissues leads to a reduced effectiveness of solid tumor treatment.

Methods

Two short-wavelength aggregation-induced emission (AIE) nanoparticles were prepared, PyTPA@PEG and TB@PEG, which have excitation wavelengths of 440 nm and 524 nm, respectively. They were characterized by UV, fluorescence, particle size and TEM. The ability of nanoparticles to produce reactive oxygen species (ROS) and kill cancer cells under different conditions was investigated in vitro, including white-light, after white-light penetrating the skin, laser. A white-light fiber for intra-tumor irradiation was customized. Finally, induced tumor elimination with fiber-mediated wPDT was confirmed in vivo.

Results

In vitro, both PyTPA@PEG and TB@PEG are more efficient in the production ROS when exposed to white-light compared to laser. However, wPDT also has a fatal flaw in that its level of ROS production after penetrating the skin is reduced to 20-40% of the original level. To this end, we have customized a white-light fiber for intra-tumor irradiation. In vivo, the fiber-mediated wPDT significantly induces tumor elimination with maximized therapeutic outcomes by irradiating the interior of the tumor. In addition, wPDT also has the advantage that its light source can be adapted to a wide range of photosensitizers (wavelength range 400-700 nm), whereas a laser of single wavelength can only target a specific photosensitizer.

Conclusion

This method of using optical fiber to increase the tissue penetration of white light can greatly improve the therapeutic effect of AIE photosensitizers, which is needed for the treatment of large/deep tumors and holds great promise in cancer treatment.

Hypoxia Alleviated and One Photo-Triggered Thermal/Dynamic Nanoplatform for Immunogenic Cell Death-Initiated Cancer Immunotherapy

Immunogenic cell death (ICD) induced by treatment modalities like chemotherapy, radiotherapy, and photothermal and photodynamic therapy has shown great potential to improve the low response rate of various solid tumors in cancer immunotherapy. However, extensive studies have revealed that the efficacy of cancer treatment is limited by the hypoxia and immunosuppression in the tumor microenvironment (TME). To address these challenges, a hypoxia alleviated and one phototriggered thermal/dynamic nanoplatform based on MnO₂@PDA/ICG-BSA (MPIB) is developed for oxygen (O₂) self-supply enhanced cancer phototherapy (PT). First, MnO₂ transfers intracellular overexpression H₂O₂ into O₂ in the acidic TME through its catalase-like activity to improve the hypoxia and also provide O₂ for the following photodynamic therapy. Then, under single NIR-808 nm light irradiation (called the "phototherapeutic window"), excellent photothermal and photodynamic performance of the MPIB is activated for combined PT. Finally, assisted with immune adjuvant cytosine-phospho-guanine, obvious ICD and systemic antitumor immunity was elicited in PT-treated mice and demonstrated significant growth inhibition on distant tumors. This MPIB-based nanoplatform highlights the promise to overcome the limitations of hypoxia and also challenges of immunosuppressive tumor microenvironments for improved cancer immunotherapy.

Combining PD-L1 blockade with immunogenic cell death induced by AIE photosensitizer to improve antitumor immunity

Immunogenic cell death (ICD) is considered an effective death mode to trigger immune response. However, the currently available efficient ICD inducers are quite limited. Endoplasmic reticulum (ER) stress is known as the precursor of ICD, which can be directly triggered by reactive oxygen species in situ. Herein, a novel photosensitizer (α-Th-TPA-PIO) based on phosphindole oxide, featuring aggregation-induced emission (AIE) is designed and prepared, which possesses good ability of hydroxyl radicals (HO^•) generation. Besides, α-Th-TPA-PIO can selectively accumulate in ER and trigger ER stress under white light irradiation, further leading to effective ICD. Combining with anti-programmed death-ligand 1 (anti-PD-L1), the synergistic effect of photodynamic therapy (PDT) and immune checkpoint blockade can achieve a significantly enhanced inhibition effect on the growth of tumors and simultaneously provoke a systemic antitumor immune response. Notably, by adopting this therapeutic strategy to bilateral and metastatic tumor models, the growth of both primary and distant subcutaneous tumors can be successfully suppressed, and metastatic tumor can also be inhibited to some degree. Taken together, this work not only provides a novel ICD photoinducer based on PDT, but also brings about a useful immunomodulatory strategy to realize superior antitumor effect.

Nanocarriers for Active Ingredients of Chinese Medicine (AIFCM) Used in Gastrointestinal Cancer Therapy

Active ingredients of Chinese medicine (AIFCM) are pharmacological substances taken from traditional Chinese medicine that show promise in treating gastrointestinal cancer. Compared with traditional chemotherapeutic drugs, AIFCM have advantages such as multi-target and multi-level treatment of gastrointestinal cancer. Nanocarriers have the following advantages, better bioavailability, passive or active targeting of tumor sites and responsive release of drugs. The use of nanocarriers for delivery of AIFCM in treatment of gastrointestinal cancer, can overcome the disadvantages of some AIFCM, such as insolubility and low bioavailability. In this review, we first outline the background on gastrointestinal cancer, main curative factors and conventional therapeutic approaches. Then, the mechanisms for AIFCM in gastrointestinal cancer therapy are presented in the following four aspects: gene regulation, immune modulation, cellular pathway transduction, and alteration of intestinal flora. Thirdly, preparation of various nanocarriers and results when combining AIFCM in gastrointestinal cancer are presented. Fourth, application of novel targeted nanocarriers and responsive nanocarriers in gastrointestinal tumors is further introduced. Finally, the application of AIFCM in the treatment of gastrointestinal cancer is summarized and prospected, hoping to shed some light on the nanocarrier-bound AIFCM in the treatment of gastrointestinal cancer.

Molecularly Self-Engineered Nanoamplifier for Boosting Photodynamic Therapy via Cascade Oxygen Elevation and Lipid ROS Accumulation

Photodynamic therapy (PDT) has been extensively explored as a noninvasive cancer treatment modality. However, the dilemma of tumor hypoxia and short half-life of singlet oxygen (¹O₂) severely restrict the therapeutic efficacy of PDT. Herein, we develop a facile three-in-one PDT nanoamplifier (AA@PPa/Hemin NPs) assembled by pyropheophorbide a (PPa), hemin, and arachidonic acid (AA). Interestingly, AA not only acts as an enabler to facilitate the assembly of PPa and hemin in the construction of ternary hybrid nanoassemblies but also acts as a lipid reactive oxygen species (ROS) amplifier for robust PDT. In tumor cells, hemin plays the role of a catalase-like catalyst that accelerates the production of oxygen (O₂) from hydrogen peroxide (H₂O₂), significantly alleviating tumor hypoxia. Under laser irradiation, vast amounts of ¹O₂ generated by PPa trigger the peroxidation of AA to produce large amounts of cytotoxic lipid ROS, immensely amplifying the efficiency of PDT by promptly eliciting cellular oxidative stress. As expected, AA@PPa/Hemin NPs exert potent antitumor activity in a 4T1 breast-tumor-bearing BALB/c mice xenograft model. Such a cascade nanohybrid amplifier provides a novel codelivery platform for accurate and effective PDT of cancer.

Aggregation-induced emission photosensitizer-based photodynamic therapy in cancer: from chemical to clinical

Cancer remains a serious threat to human health owing to the lack of effective treatments. Photodynamic therapy (PDT) has emerged as a promising non-invasive cancer treatment that consists of three main elements: photosensitizers (PSs), light and oxygen. However, some traditional PSs are prone to aggregation-caused quenching (ACQ), leading to reduced reactive oxygen species (ROS) generation capacity. Aggregation-induced emission (AIE)-PSs, due to their distorted structure, suppress the strong molecular interactions, making them more photosensitive in the aggregated state instead. Activated by light, they can efficiently produce ROS and induce cell death. PS is one of the core factors of efficient PDT, so proceeding from the design and preparation of AIE-PSs, including how to manipulate the electron donor (D) and receptor (A) in the PSs configuration, introduce heavy atoms or metal complexes, design of Type I AIE-PSs, polymerization-enhanced photosensitization and nano-engineering approaches. Then, the preclinical experiments of AIE-PSs in treating different types of tumors, such as ovarian cancer, cervical cancer, lung cancer, breast cancer, and its great potential clinical applications are discussed. In addition, some perspectives on the further development of AIE-PSs are presented. This review hopes to stimulate the interest of researchers in different fields such as chemistry, materials science, biology, and medicine, and promote the clinical translation of AIE-PSs.

Cu-Hemin Nanosheets and Indocyanine Green Co-Loaded Hydrogel for Photothermal Therapy and Amplified Photodynamic Therapy

Near-infrared (NIR) organic small molecule indocyanine green (ICG) could respond well to 808 nm laser to promote local high temperature and ROS generation for realizing photothermal therapy (PTT)/photodynamic therapy (PDT). However, the high content of GSH in the tumor microenvironment (TME) limited the further therapeutic performance of ICG. Herein, injectable agarose in situ forming NIR-responsive hydrogels (CIH) incorporating Cu-Hemin and ICG were prepared for the first time. When CIH system was located to the tumor tissue through local injection, the ICG in the hydrogel could efficiently convert the light energy emitted by the 808 nm laser into thermal energy, resulting in the heating and softening of the hydrogel matrix, which releases the Cu-Hemin. Then, the over-expressed GSH in the TME could also down-regulated by Cu-Hemin, which amplified ICG-mediated PDT. In vivo experiments validated that ICG-based PDT/PTT and Cu-Hemin-mediated glutathione depletion could eliminate cancer tissues with admirable safety. This hydrogel-based GSH-depletion strategy is instructive to improve the objective response rate of PDT.

Modulating albumin-mediated transport of peptide-drug conjugates for antigen-specific Treg induction

The therapeutic potential of antigen-specific regulatory T cells (Treg) has been extensively explored, leading to the development of several tolerogenic vaccines. Dexamethasone-antigen conjugates represent a prominent class of tolerogenic vaccines that enable coordinated delivery of antigen and dexamethasone to target immune cells. The importance of nonspecific albumin association towards the biodistribution of antigen-adjuvant conjugates has gained increasing attention, by which hydrophobic and electrostatic interactions govern the association capacity. Using an ensemble of computational and experimental techniques, we evaluate the impact of charged residues adjacent to the drug conjugation site in dexamethasone-antigen conjugates (Dex-K/E4-OVA323, K: lysine, E: glutamate) towards their albumin association capacity and induction of antigen-specific Treg. We find that Dex-K4-OVA323 possesses a higher albumin association capacity than Dex-E4-OVA323, leading to enhanced liver distribution and antigen-presenting cell uptake. Furthermore, using an OVA323-specific adoptive-transfer mouse model, we show that Dex-K4-OVA323 selectively upregulated OVA323-specific Treg cells, whereas Dex-E4-OVA323 exerted no significant effect on Treg cells. Our findings serve as a guide to optimize the functionality of dexamethasone-antigen conjugate amid switching vaccine epitope sequences. Moreover, our study demonstrates that moderating the residues adjacent to the conjugation sites can serve as an engineering approach for future peptide-drug conjugate development.

Nano-Albumin Particles Loaded with miR-20a Inhibitor Targeting Met Protein to Reverse Proliferation of Intestinal Cancer Cells

This study explored miR-20a’s role in intestinal cancer cells. SW480 cell line was divided into control group, agonist group, inhibitor group, and negative control group, followed by analysis of cell proliferation, apoptosis, Met, Bad, and Bcl-2 protein expressions. Results showed that miR-20a expression in the agonist group was the highest, followed by blank group and negative control group, and inhibitor group was lowest. S-phase and G2/M cell number from inhibitor group was lowest, and cell apoptosis rate was highest. However, the agonist group showed contrary changes. There was no difference in G0/G1 phase cell number among the four groups (P > 0.05). Moreover, the expressions of Bad, Bcl-2, Met, Wnt, β-catenin, and p-Wnt in inhibitor group were all lower, while the expressions in agonist group were all high (P < 0.05). S-phase and G2/M cell number in inhibitor group was lowest, while cell apoptosis was highest. The agonist group was opposite, with G0/G1 phase cells in each group showing no difference (P > 0.05). Wnt, β-catenin, and p-Wnt expressions were lowest in the inhibitor group, while the agonist group was opposite. These results together showed that the miR-20a directly targeted and regulated Met protein. Finally, the miR-20a inhibited intestinal cancer cell proliferation mainly through inhibiting Wnt/β-catenin signaling activity.

Biodegradable Materials with Disulfide-Bridged-Framework Confine Photosensitizers for Enhanced Photo-Immunotherapy

Purpose

Photodynamic therapy (PDT) with spatiotemporal controlled and noninvasive advantages has obtained growing attention in cancer treatment. Nevertheless, PDT still suffers from self-aggregation-induced photosensitizer quenching and reactive oxygen species (ROS) scavenging in cancer cells with abundant glutathione (GSH) pools, leading to insufficient performance.

Methods

In this study, we develop a versatile nanocarrier (SSNs) with a disulfide-bond-bridged silica framework for enhanced photo-immunotherapy. Such SSNs spatially confine photosensitizers Ce6 in the matrix to prevent self-aggregation. Under the high GSH level of cancer cells, the disulfide-bond-bridged framework was degradable and triggered the exposure of photosensitizers to oxygen, accelerating the ROS generation during PDT. In addition, GSH depletion via the break of the disulfide-bond increased the ROS level, together resulting in efficient tumor killing outcomes with a considerable immunogenic cell death effect in vitro. Importantly, the SSNs@Ce6 accumulated in the tumor site and exhibited enhanced PDT efficacy with low systemic toxicity in vivo.

Results

The GEN-loaded nanoplatform (Ag-MONs@GEN) showed glutathione-responsive matrix degradation, resulting in the simultaneous controlled release of GEN and silver ions. Ag-MONs@GEN exhibited excellent anti-bacterial activities than Ag-MONs and GEN alone, especially enhancing synergetic effects against four antibiotic-resistant bacteria including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis. Moreover, Ag-MONs@GEN showed good biocompatibility on L929 and HUVECS.

Conclusion

Notably, SSNs@Ce6-mediated PDT completely eradicated 4T1 tumors when combined with the PD-1 checkpoint blockade. Overall, the confinement of photosensitizers in a biodegradable disulfide-bridged-framework provides a promising strategy to unleash the potential of photosensitizers in PDT, especially in combined cancer photo-immunotherapy.