Polyphotosensitizer-Based Nanoparticles with Michael Addition Acceptors Inhibiting GST Activity and Cisplatin Deactivation for Enhanced Chemotherapy and Photodynamic Immunotherapy

The role of cisplatin in modulating the tumor immune microenvironment and its combination therapy strategies: a new approach to enhance anti-tumor efficacy

Cisplatin is a platinum-based drug that is frequently used to treat multiple tumors. The anti-tumor effect of cisplatin is closely related to the tumor immune microenvironment (TIME), which includes several immune cell types, such as the tumor-associated macrophages (TAMs), cytotoxic T-lymphocytes (CTLs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), and natural killer (NK) cells. The interaction between these immune cells can promote tumor survival and chemoresistance, and decrease the efficacy of cisplatin monotherapy. Therefore, various combination treatment strategies have been devised to enhance patient responsiveness to cisplatin therapy. Cisplatin can augment anti-tumor immune responses in combination with immune checkpoint blockers (such as PD-1/PD-L1 or CTLA4 inhibitors), lipid metabolism disruptors (like FASN inhibitors and SCD inhibitors) and nanoparticles (NPs), resulting in better outcomes. Exploring the interaction between cisplatin and the TIME will help identify potential therapeutic targets for improving the treatment outcomes in cancer patients.

Drug Delivery Platform Targeting MMP9 in Combination with Photothermal Therapy to Improve Tumor Chemosensitivity

Tumor chemotherapy insensitivity poses a significant challenge in cancer treatment, with angiogenesis being a key contributing factor. Angiogenesis supplies oxygen and nutrients to tumor cells, thereby impairing treatment outcomes. Based on these findings, an MMP9-responsive carbon quantum dot-based nanoplatform (MMP9i@MTX@CQDs) encapsulating methotrexate (MTX) and an MMP9 inhibitor (MMP9i) is developed to overcome chemotherapy insensitivity. Targeting the high expression of MMP9 in tumors, the platform releases its payload in a responsive manner. Under near-infrared (NIR) irradiation, the system effectively downregulated angiogenesis-related molecules, including VEGF and CD31, and inhibited the Wnt/β-catenin signaling pathway, thereby reversing chemotherapy insensitivity. This nanoplatform integrates MMP9-responsive CQDs with MTX, enabling photothermal therapy (PTT) and MMP9 inhibition, offering a robust and safe strategy to sensitize tumors to chemotherapy.

Highly Emissive Platinum(II) Metallacage in the Near-Infrared Region for Synergistic Chemo-Photodynamic Therapy

Highly emissive metallacages that generate reactive oxygen species (ROS) are important to synergistic cancer therapy, but it is still challenging to balance the emission and phototheranostic properties. Herein, a metallacage of DTPABT-Mc is prepared. It is observed that emission in the near-infrared region from 600 to 1000 nm with a high photoluminescence quantum yield value of 7.92% in solids is recorded for DTPABT-Mc. In addition, the ability to produce both type I and type II ROS under light irradiation is also observed, leading to potential application in photodynamic therapy (PDT) and chemotherapy. After that, 4T1@DTPABT-Mc-NPs, covering DTPABT-Mc nanoparticles with 4T1 cell membranes, are prepared to enhance their tumor-targeting ability. This finally results in effective therapeutic performance in vivo, effectively inhibiting tumor growth. These results suggest that DTPABT-Mc-NPs exhibit excellent synergistic therapeutic effects by combining PDT and chemotherapy, providing new ideas to design agents for diagnosis and therapy in the future.

Responsive boronate ester lipid nanoparticles for enhanced delivery of veliparib and platinum (IV) prodrug in chemotherapy

The chemotherapeutic effectiveness of breast cancer treatment is currently unsatisfactory due to inadequate drug delivery, suboptimal drug release, and drug inactivation. Herein, we present an innovative boronate ester lipid nanoformulation to improve the delivery of a platinum (IV) prodrug (Pt-C12) and veliparib (Veli), aiming to increase their therapeutic efficacy through a synergistic effect. We identify the optimal ratio of Pt-C12 to Veli for achieving synergy in vitro, followed by the encapsulation of Pt-C12 and Veli in lipid nanoparticles (NPs) incorporating responsive boronate ester lipids (LPC-PPE) to produce responsive lipid NPs (LPV NPs). These LPV NPs demonstrate high sensitivity to low levels of hydrogen peroxide (H2O2), enabling efficient drug release. In contrast, the nonresponsive lipid NP (DPV NP) control shows minimal responsiveness to H2O2. Furthermore, acidic tumor microenvironments trigger phenylboronic acid (PBA) generation from LPC-PPE in the LPV NPs. Compared with DPV NPs, the interaction between PBA on the LPV NPs and sugar components on tumor cells significantly improves LPV NP cellular uptake and lysosomal escape in vitro. Due to the enhanced cellular delivery and the synergistic drug combination, the LPV NPs induce an increase in apoptosis in 4 T1 cells compared with control groups. Moreover, the LPV NPs exhibit greater efficiency of drug delivery to tumors than the DPV NPs, and have a greater inhibitory effect on tumors than the controls. Overall, our findings highlight the potential of functional lipids and synergistic drug combinations in overcoming obstacles in breast cancer treatment and advancing the development of responsive delivery systems.

Injectable celastrol-loading emulsion hydrogel for immunotherapy of low-immunogenic cancer

Immunotherapy, exemplified by immune checkpoint blockade (ICB), has been extensively employed in antitumor treatments. Nevertheless, its efficacy in addressing low-immunogenic tumors has not yielded satisfactory results, primarily due to the depletion and inadequate infiltration of effector T cells within the tumor microenvironment (TME). Here, we construct an injectable water-in-oil emulsion hydrogel to load clinically used Celastrol (Gel@Cel), which addresses the limitations of Cel's hydrophobicity. Cel can both inhibit tumor cell proliferation and promote tumor cell apoptosis, while simultaneously inducing immunogenic cell death, through activation of the AKT and MAPK pathways. In a model of clinically refractory hepatocellular carcinoma with malignant ascites, intraperitoneal administration of Gel@Cel significantly inhibits tumor progression and activates antitumor immune effects through lipase-controlled release of Cel, as compared to free Cel. Intriguingly, the Gel@Cel induces the activation of dendritic cells, resulting in the infiltration of cytotoxic T cells in the TME of ascites. Furthermore, the administration of Cel increases the expression of programmed cell death protein ligand-1 (PD-L1) in tumor cells. Moreover, combining the PD-1 antibody (αPD-1) with Gel@Cel further enhances the antitumor effect and amplifies the immune activation. In conclusion, Gel@Cel exhibits promising therapeutic potential in the treatment of low-immunogenic tumors, especially when combined with ICB therapy.

Pt(IV) prodrug as a potent nanosonosensitizer self-cyclically amplifies sonodynamic-chemotherapy with dually reversing cisplatin resistance

Although sonodynamic therapy (SDT) has shown promising advancements in combination with chemotherapy, it frequently necessitates the requirement of conventional sonosensitizers and chemotherapeutic agents, engendering intricate systems and potential drug resistance. Herein, we fabricated a potent Pt(IV)-poly(amino acid) coordination nanosonosensitizer (PHPt) with dual reversal of cisplatin resistance, producing abundant 1O2 and ˙OH upon ultrasound irradiation without the use of any external sonosensitizers. The Pt(IV) prodrug in PHPt efficiently reduced to cisplatin through SDT-induced ˙H and glutathione (GSH), inducing ˙OH accumulation and CDDP release, which further amplified the oxidative stress on SDT. Moreover, the high GSH depletion performance of PHPt and administration of aspirin effectively inhibited cisplatin detoxification and activation of the nuclear factor-kappa B pathway, respectively. This cooperative action between the Pt(IV) prodrug and SDT in the tumor microenvironment promoted self-cyclic amplification of sonodynamic-chemotherapy, achieving a significant tumor inhibition rate of 99.4%. Thus, this study offers novel perspectives on the sonosensitizer development and cisplatin application in SDT.

Sonodynamic Therapy by Reactive Oxygen Species Generation-Responsive Pseudo-Semiconducting Polymer Nanoparticles Combined with a Fibroblast Growth Factor Receptor Inhibitor for Enhancing Immunotherapy in Bladder Cancer

Sonodynamic therapy, a treatment modality recently widely used, is capable of disrupting the tumor microenvironment by inducing immunogenic cell death (ICD) and enhancing antitumor immunity during immunotherapy. Erdafitinib, an inhibitor of the fibroblast growth factor receptor, has demonstrated potential benefits for treating bladder cancer. However, Erdafitinib shows effectiveness in only a small number of patients, and the majority of patients responding positively to the medication have "immune-cold" tumors. To increase the therapeutic efficacy of Erdafitinib, we have herein developed a biodegradable pseudoconjugate polymer (PSP) with sonodynamic capabilities. Erdafitinib could be efficiently encapsulated in nanoparticles (NP-PE) prepared through the self-assembly of PSP with an oxidation-sensitive polymer (P1). Under ultrasound conditions, NP-PE effectively induced cytotoxicity by producing reactive oxygen species and further triggering ICD. Compared with Erdafitinib, NP-PE inhibited the expression of FGFR3 to a higher extent. In animal models with bladder cancer, NP-PE inhibited tumor growth, stimulated antitumor immunity, and synergized with antiprogrammed cell death-ligand 1 (aPD-L1), offering a novel approach for the treatment of bladder cancer.

AIEgen-self-assembled nanoparticles with anti-PD-L1 antibody functionalization realize enhanced synergistic photodynamic therapy and immunotherapy against malignant melanoma

Immune checkpoint inhibitors (ICIs) become integral in clinical practice, yet their application in cancer therapy is constrained by low overall response rates and the primary resistance of cancers to ICIs. Herein, this study proposes aggregation-induced emission (AIE)-based nanoparticles (NPs) for a more effective and synergistic approach combining immunotherapy and photodynamic therapy (PDT) to achieve higher responses than anti-PD-L1 monotherapy. The TBP@aPD-L1 NPs are constructed by functionalizing azide group-modified TBP-2 (TBP-N3) with anti-PD-L1 antibodies via the DBCO-S-S-PEG2000-COOH linker. The anti-PD-L1 target the tumor cells and promote the TBP-N3 accumulation in tumors for enhanced PDT. Notably, the TBP-N3, featuring aggregation-induced emission, boosts reactive oxygen species (ROS) generation through both type I and type II processes for enhanced PDT. The TBP@aPD-L1-mediated PDT induces more powerful effects of direct tumor cell-killing and further elicits effective immunogenic cell death (ICD), which exerts anti-tumor immunity by activating T cells for ICI treatment and reshapes the tumor immune microenvironment (TIME), thereby enhancing the efficacy of PD-L1 blockade of anti-PD-L1. Consequently, TBP@aPD-L1 NPs demonstrated significantly enhanced inhibition of tumor growth in the mouse model of malignant melanoma (MM). Our NPs act as a facile and effective drug delivery platform for enhanced immunotherapy combined with enhanced PDT in treating MM.

Enhanced Photothermal/Immunotherapy under NIR Irradiation Based on Hollow Mesoporous Responsive Nanomotor

In this research, a hollow mesoporous responsive nanomotor was proposed for enhanced photothermal/immunotherapy under near infrared (NIR) irradiation. HA-HMCuS/AS as the nanomotor composed of hollow mesoporous copper sulfide (HMCuS) loaded with artesunate (AS) and hyaluronic acid (HA) was utilized to induce the polarization of tumor-associated macrophages. At the beginning, ResNet18 deep learning model was utilized to predict the Brunauer-Emmett-Teller (BET) surface area of HMCuS based on the morphology data set which was obtained from our conventional research. And then, we predicted that the as-synthesized HMCuS has a large surface area, which is beneficial for drug loading. Then, upon near-infrared light irradiation, HA-HMCuS/AS exhibited significant cytotoxicity against breast cancer cells and induced tumor thermal ablation. Additionally, HA-HMCuS/AS was found to inhibit the expression of TREM2 at the tumor site, promoting the transition of M2-type macrophages to M1-type macrophages in tumor tissue and enhancing the inflammatory response at the tumor site. In addition, photothermal therapy enabled tumor cells to release tumor-associated antigen and injury-related molecular patterns, promote the maturation and metastasis of dendritic cells, and further activate the body's specific antitumor immune response. By combining photothermal therapy with immunotherapy, the HA-HMCuS nanomotor demonstrated even more robust tumor ablation and suppression effects.

Targeting Hypoxia and Autophagy Inhibition via Delivering Sonodynamic Nanoparticles With HIF-2α Inhibitor for Enhancing Immunotherapy in Renal Cell Carcinoma

Immune checkpoint blockers (ICBs) therapy stands as the first-line treatment option for advanced renal cell carcinoma (RCC). However, its effectiveness is hindered by the immunosuppressive tumor microenvironment (TME). Sonodynamic therapy (SDT) generates tumor cell fragments that can prime the host's antitumor immunity. Nevertheless, the hypoxic microenvironment and upregulated autophagy following SDT often lead to cancer cell resistance. In response to these challenges, a hypoxia-responsive polymer (Poly(4,4'-azobisbenzenemethanol-PMDA)-mPEG5k, P-APm) encapsulating both a HIF-2α inhibitor (belzutifan) and the ultrasonic sensitize (Chlorin e6, Ce6) is designed, to create the nanoparticle APm/Ce6/HIF. APm/Ce6/HIF combined with ultrasound (US) significantly suppresses tumor growth and activates antitumor immunity in vivo. Moreover, this treatment effectively transforms the immunosuppressive microenvironment from "immune-cold" to "immune-hot", thereby enhancing the response to ICBs therapy. The findings indicate that APm/Ce6/HIF offers a synergistic approach combining targeted therapy with immunotherapy, providing new possibilities for treating RCC.

Bioorthogonal Chemistry-Guided Inhalable Nanoprodrug to Circumvent Cisplatin Resistance in Orthotopic Nonsmall Cell Lung Cancer

Pulmonary delivery of anticancer therapeutics has shown encouraging performance in treating nonsmall cell lung cancer (NSCLC), which is characterized by high aggressiveness and poor prognosis. Cisplatin, a key member of the family of DNA alkylating agents, is extensively employed during NSCLC therapy. However, the development of chemoresistance and the occurrence of side effects severely impede the long-term application of cisplatin-based chemotherapies. Herein, we propose a meaningful strategy to precisely treat cisplatin-resistant NSCLC based on the combination of bioorthogonal chemistry with an inhalation approach. Ethacraplatin (EA-Pt), a platinum prodrug (IV), was synthesized and encapsulated in nitric oxide (NO)-containing micelles to overcome cisplatin chemoresistance. By further modifying bioorthogonal molecules in this nanoplatform (EA-Pt@MDBCO), an improved targeting performance toward pulmonary cancerous regions is achieved after prelabeling with azide via inhalation. Upon entering acidic cancer cells, EA-Pt is swiftly released due to the pH sensitivity of bioorthogonal micelles, which enables its bifunctions to inhibit glutathione S-transferase activity and deplete intracellular glutathione, eventually reversing cisplatin resistance. Moreover, the released NO also improves the overall therapeutic outcome against NSCLC. Consequently, inhalable EA-Pt@MDBCO prelabeled by azide effectively inhibits the progression of cisplatin-resistant orthotopic NSCLC, offering a feasible nanostrategy to expand the treatment options for NSCLC.

Homologous Tumor Cell-Derived Biomimetic Nano-Trojan Horse Integrating Chemotherapy with Genetherapy for Boosting Triple-Negative Breast Cancer Therapy

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that carries the worst prognosis and lacks specific therapeutic targets. To achieve accurate "cargos" delivery at the TNBC site, we herein constructed a novel biomimetic nano-Trojan horse integrating chemotherapy with gene therapy for boosting TNBC treatment. Briefly, we initially introduce the diselenide-bond-containing organosilica moieties into the framework of mesoporous silica nanoparticles (MONs), thereby conferring biodegradability to intratumoral redox conditions in the obtained MONSe. Subsequently, doxorubicin (Dox) and therapeutic miR-34a are loaded into MONSe, thus achieving the combination of chemotherapy and gene-therapy. After homologous tumor cell membrane coating, the ultimate homologous tumor cell-derived biomimetic nano-Trojan horse (namely, MONSe@Dox@miR-34a@CM) can selectively enter the tumor cells in a stealth-like fashion. Notably, such a nanoplatform not only synergistically eradicated the tumor but also inhibited the proliferation of breast cancer stem-like cells (BCSCs) in vitro and in vivo. With the integration of homologous tumor cell membrane-facilitated intratumoral accumulation, excellent biodegradability, and synergistic gene-chemotherapy, our biomimetic nanocarriers hold tremendous promise for the cure of TNBC in the future.

Platinum-based chemotherapy: trends in organic nanodelivery systems

Despite the investment in platinum drugs research, cisplatin, carboplatin and oxaliplatin are still the only Pt-based compounds used as first line treatments for several cancers, with a few other compounds being approved for administration in some Asian countries. However, due to the severe and worldwide impact of oncological diseases, there is an urge for improved chemotherapeutic approaches. Furthermore, the pharmaceutical application of platinum complexes is hindered by their inherent toxicity and acquired resistance. Nanodelivery systems rose as a key strategy to overcome these challenges, with recognized versatility and ability towards improving the safety, bioavailability and efficacy of the available drugs. Among the known nanocarriers, organic systems have been widely applied, taking advantage of their potential as drug vehicles. Researchers have mainly focused on the development of lipidic and polymeric carriers, including supramolecular structures, with an overall improvement of encapsulated platinum complexes. Herein, an overview of recent trends and strategies is presented, with the main focus on the encapsulation of platinum compounds into organic nanocarriers, showcasing the evolution in the design and development of these promising systems. This comprehensive review highlights formulation methods as well as characterization procedures, providing insights that may be helpful for the development of novel platinum nanocarriers aiming at future pharmaceutical applications.

Nanomedomics

Nanomaterials have attractive physicochemical properties. A variety of nanomaterials such as inorganic, lipid, polymers, and protein nanoparticles have been widely developed for nanomedicine via chemical conjugation or physical encapsulation of bioactive molecules. Superior to traditional drugs, nanomedicines offer high biocompatibility, good water solubility, long blood circulation times, and tumor-targeting properties. Capitalizing on this, several nanoformulations have already been clinically approved and many others are currently being studied in clinical trials. Despite their undoubtful success, the molecular mechanism of action of the vast majority of nanomedicines remains poorly understood. To tackle this limitation, herein, this review critically discusses the strategy of applying multiomics analysis to study the mechanism of action of nanomedicines, named nanomedomics, including advantages, applications, and future directions. A comprehensive understanding of the molecular mechanism could provide valuable insight and therefore foster the development and clinical translation of nanomedicines.

Localization of Cancer Cells for Subsequent Robust Photodynamic Therapy by ROS Responsive Polymeric Nanoparticles With Anti-Metastasis Complexes NAMI-A

Photodynamic therapy (PDT), as a new type of light-mediated reactive oxygen species (ROS) cancer therapy, has the advantages of high therapeutic efficiency, non-resistance, and less trauma than traditional cancer therapy such as surgery, radiotherapy, and chemotherapy. However, oxygen-dependent PDT further exacerbates tumor metastasis. To this end, a strategy that circumvents tumor metastasis to improve the therapeutic efficacy of PDT is proposed. Herein, a near-infrared light-activated photosensitive polymer is synthesized and branched the anti-metastatic ruthenium complex NAMI-A on the side, which is further assembled to form nanoparticles (NP2) for breast cancer therapy. NP2 can kill tumor cells by generating ROS under 808 nm radiation (NP2 + L), reduce the expression of matrix metalloproteinases (MMP2/9) in cancer cells, decrease the invasive and migration capacity of cancer cells, and eliminate cancer cells. Further animal experiments show that NP2 + L can inhibit tumor growth and reduce liver and lung metastases. In addition, NP2 + L can activate the immune system in mice to avoid tumor recurrence. In conclusion, a PDT capable of both preventing tumor metastasis and precisely hitting the primary tumor to achieve effective treatment of highly metastatic cancers is developed.

cGAS-STING Pathway Activation and Systemic Anti-Tumor Immunity Induction via Photodynamic Nanoparticles with Potent Toxic Platinum DNA Intercalator Against Uveal Melanoma

The cGAS-STING pathway, as a vital innate immune signaling pathway, has attracted considerable attention in tumor immunotherapy research. However, STING agonists are generally incapable of targeting tumors, thus limiting their clinical applications. Here, a photodynamic polymer (P1) is designed to electrostatically couple with 56MESS-a cationic platinum (II) agent-to form NPPDT -56MESS. The accumulation of NPPDT -56MESS in the tumors increases the efficacy and decreases the systemic toxicity of the drugs. Moreover, NPPDT -56MESS generates reactive oxygen species (ROS) under the excitation with an 808 nm laser, which then results in the disintegration of NPPDT -56MESS. Indeed, the ROS and 56MESS act synergistically to damage DNA and mitochondria, leading to a surge of cytoplasmic double-stranded DNA (dsDNA). This way, the cGAS-STING pathway is activated to induce anti-tumor immune responses and ultimately enhance anti-cancer activity. Additionally, the administration of NPPDT -56MESS to mice induces an immune memory effect, thus improving the survival rate of mice. Collectively, these findings indicate that NPPDT -56MESS functions as a chemotherapeutic agent and cGAS-STING pathway agonist, representing a combination chemotherapy and immunotherapy strategy that provides novel modalities for the treatment of uveal melanoma.

Anatase TiO2-x and zwitterionic porphyrin polymer-based nanocomposite for enhanced cancer photodynamic therapy

Photodynamic therapy has been used as a treatment option for cancer; however, the existing TiO2 photosensitizer does not have the ability to specifically target cancer cells. This lack of selectivity reduces its effectiveness in overcoming cancer resistance. To improve photodynamic therapy outcomes, an innovative solution is proposed. In this study, we report on the compounding of a zwitterionic covalent organic polymer (COP) with a TiO2 photosensitizer for the first time. The aim is to overcome cancer cellular resistance. A one-pot synthetic strategy, which includes the construction of a porphyrin-based COP has been employed. This strategy has also been applied to the rapid preparation of anatase defective TiO2 (TiO2-x). To improve the hydrophilic and antifouling properties of the polymer, zwitterion L-cysteine has been conjugated with a porphyrin-based COP using a thiol-ene "click chemistry" reaction. The novel zwitterionic porphyrin-based COP has the ability to trigger biodegradation under the acid microenvironment due to the presence of acid-sensitive β-thioether esters. When combined with TiO2-x, the resultant nanocomposite produces an enhanced photodynamic therapy effect for drug-resistant cancer cells under NIR laser irradiation. This is due to the strong mutual sensitization of zwitterionic porphyrin-based COP and TiO2-x. Importantly, the nanocomposite delivery system exhibits excellent cytocompatibility in the dark and has the potential to improve the accuracy of cancer diagnosis through fluorescence imaging. The results of this study demonstrate the potential application of this alternative nanocomposite delivery system for remote-controllable photodynamic therapy of tumors.

Nanotechnology-Assisted Immunogenic Cell Death for Effective Cancer Immunotherapy

Tumor vaccines have been used to treat cancer. How to efficiently induce tumor-associated antigens (TAAs) secretion with host immune system activation is a key issue in achieving high antitumor immunity. Immunogenic cell death (ICD) is a process in which tumor cells upon an external stimulus change from non-immunogenic to immunogenic, leading to enhanced antitumor immune responses. The immune properties of ICD are damage-associated molecular patterns and TAA secretion, which can further promote dendritic cell maturation and antigen presentation to T cells for adaptive immune response provocation. In this review, we mainly summarize the latest studies focusing on nanotechnology-mediated ICD for effective cancer immunotherapy as well as point out the challenges.