H2O2 self-supplying degradable epitope imprinted polymers for targeted fluorescence imaging and chemodynamic therapy

Advances in H2O2-supplying materials for tumor therapy: synthesis, classification, mechanisms, and applications

Hydrogen peroxide (H2O2) as a reactive oxygen species produced by cellular metabolism can be used in antitumor therapy. However, the concentration of intracellular H2O2 limits its application. Some materials could enhance the concentration of intracellular H2O2 to strengthen antitumor therapy. In this review, the recent advances in H2O2-supplying materials in terms of promoting intracellular H2O2 production and exogenous H2O2 supply are summarized. Then the mechanism of H2O2-supplying materials for tumor therapy is discussed from three aspects: reconstruction of the tumor hypoxia microenvironment, enhancement of oxidative stress, and the intrinsic anti-tumor ability of H2O2-supplying materials. In addition, the application of H2O2-supplying materials for tumor therapy is discussed. Finally, the future of H2O2-supplying materials is presented. This review aims to provide a novel idea for the application of H2O2-supplying materials in tumor therapy.

Thermoresponsive and Substrate Self-Cycling Nanoenzyme System for Efficient Tumor Therapy

Cerium oxide (CeO2-x) performs well in photothermal and catalytic properties due to its abundance of oxygen vacancies. Based on this, we designed a thermosensitive therapeutic nanoplatform to achieve continuous circular drug release in tumor. It can solve the limitation caused by insufficient substrate in the process of tumor treatment. Briefly, CeO2-x and camptothecin (CPT) were wrapped in an agarose hydrogel, which could be melted by the photothermal effect of CeO2-x. At the same time, the local temperature increase provided photothermal treatment, which could induce the apoptosis of tumor cell. After that, CPT was released to damage the DNA in tumor cells to realize chemical treatment. In addition, CPT could active nicotinamide adenine dinucleotide oxidase to react with O2 to increase the intracellular H2O2. After that, the exposed CeO2-x could catalyze H2O2 to generate cytotoxic reactive oxygen species for chemodynamic therapy. More importantly, CeO2-x could catalyze H2O2 to produce O2, which could combine with the catalytic action of CPT to construct a substrate self-cycling nanoenzyme system. Overall, this self-cycling nanoplatform released hypoxia in the tumor microenvironment and built a multimode tumor treatment, which achieved an ideal antitumor affect.

Cascade Self-Generation of Carbon Monoxide Triggered by Photoinduced Holes for Efficient Hypoxic Tumors Therapy

It still remains challenging to design multifunctional therapeutic reagents for effective cancer therapy under a unique tumor microenvironment including insufficient endogenous H2O2 and O2, low pH, and a high concentration of glutathione (GSH). In this work, a CO-based phototherapeutic system triggered by photogenerated holes, which consisted of ionic liquid (IL), the CO prodrug Mn2(CO)10, and iridium(III) porphyrin (IrPor) modified carbonized ZIF-8-doped graphitic carbon nitride nanocomposite (IL/ZCN@Ir(CO)), was designed for cascade hypoxic tumors. Upon light irradiation, the photogenerated holes on IL/ZCN@Ir(CO) oxidize water into H2O2, which subsequently induces Mn2(CO)10 to release CO. Meanwhile, IrPor can convert H2O2 to hydroxyl radical (•OH) and subsequent singlet oxygen (1O2), which further triggers CO release. Moreover, the degraded MnO2 shows activity for glutathione (GSH) depletion and mimics peroxidase, leading to GSH reduction and •OH production in tumors. Thus, this strategy can in situ release high concentrations of CO and reactive oxygen species (ROS) and deplete GSH to efficiently induce cell apoptosis under hypoxic conditions, which has a high inhibiting effect on the growth of tumors, offering an attractive strategy to amplify CO and ROS generation to meet therapeutic requirements in cancer treatment.

pH-Responsive Multifunctional Nanoplatforms with Reactive Oxygen Species-Controlled Release of CO for Enhanced Oncotherapy

Recently, various nanomaterials have drawn increasing attention for enhanced tumor therapy. However, a lack of tumor uptake and insufficient generation of cytotoxic agents have largely limited the antitumor efficacy in vivo. Herein, a multifunctional nanoplatform (IL@CPPor(CO)) was constructed with pH-responsive copper peroxide nanoparticles (CPNP) that are capable of self-supplying H2O2, a radical-sensitive carbonic oxide (CO) donor (Fe3(CO)12), photosensitizer Iridium(III) meso-tetra (N-methyl-4-pyridyl)porphyrin pentachloride (IrPor), and ionic liquid (IL) for enhanced oncotherapy. Under acidic conditions, the CPNP could decompose to release H2O2 and Cu2+. The concomitant generation of H2O2 could efficiently trigger Fe3(CO)12 to release the CO in situ. On the other hand, Cu2+ possesses both glutathione depletion and Fenton-like properties. In addition, IrPor has both peroxidase-like activity and photosensitizer properties to produce reactive oxygen species (ROS) in tumors. The released ROS could trigger the rapid intracellular release of CO. More importantly, released CO and ROS could promote cell apoptosis and improve the therapeutic efficacy. Moreover, due to the pH-dependent ROS generation property, the IL@CPPor(CO) exhibited high tumor accumulation, low toxicity, and good biocompatibility, which enabled effective tumor growth inhibition with minimal side effects in vivo. This work provides a novel multifunctional nanoplatform that combined photodynamic therapy with CDT and CO to improve therapeutic efficacy.

CaO2nanomedicines: a review of their emerging roles in cancer therapy

Metal peroxide-based nanomedicines have emerged as promising theranostic agents for cancer due to their multifunctional properties, including the generation of bioactive small molecules such as metal ions, H2O2, O2, and OH-. Among these metal peroxides, calcium peroxide (CaO2) nanomedicines have attracted significant attention due to their facile synthesis and good biocompatibility. CaO2nanoparticles have been explored for cancer treatment through three main mechanisms: (1) the release of O2, which helps alleviate tumor hypoxia and enhances oxygen-dependent therapies such as chemotherapy, photodynamic therapy, and immunotherapy; (2) the generation of H2O2, a precursor for ·OH generation, which enables cancer chemodynamic therapy; and (3) the release of Ca2+ions, which induce calcium overload and promote cell apoptosis (called ion-interference therapy). This review provides a comprehensive summary of recent examples of CaO2nanoparticle-based cancer therapeutic strategies, as well as discusses the challenges and future directions in the development of CaO2nanomedicines for cancer treatment.

Development of the Cu/ZIF-8 MOF Acid-Sensitive Nanocatalytic Platform Capable of Chemo/Chemodynamic Therapy with Improved Anti-Tumor Efficacy

Recently, the combination of chemotherapy and chemodynamic therapy (CDT) has become a desirable strategy in the treatment of cancer. However, a satisfactory therapeutic outcome is often difficult to achieve due to the deficiency of endogenous H₂O₂ and O₂ in the tumor microenvironment. In this study, a CaO₂@DOX@Cu/ZIF-8 nanocomposite was prepared as a novel nanocatalytic platform to enable the combination of chemotherapy and CDT in cancer cells. The anticancer drug doxorubicin hydrochloride (DOX) was loaded onto calcium peroxide (CaO₂) nanoparticles (NPs) to form CaO₂@DOX, which was then encapsulated in a copper zeolitic imidazole ester MOF (Cu/ZIF-8) to form CaO₂@DOX@Cu/ZIF-8 NPs. In the mildly acidic tumor microenvironment, CaO₂@DOX@Cu/ZIF-8 NPs rapidly disintegrated, releasing CaO₂, which reacted with water to generate H₂O₂ and O₂ in the tumor microenvironment. The ability of CaO₂@DOX@Cu/ZIF-8 NPs to combine chemotherapy and CDT was assessed by conducting cytotoxicity, living dead staining, cellular uptakes, H&E staining, and TUNEL assays in vitro and in vivo. The combination of chemotherapy and CDT of CaO₂@DOX@Cu/ZIF-8 NPs had a more favorable tumor suppression effect than the nanomaterial precursors, which were not capable of the combined chemotherapy/CDT.

Molecularly Imprinted Carriers for Diagnostics and Therapy-A Critical Appraisal

Simultaneous diagnostics and targeted therapy provide a theranostic approach, an instrument of personalized medicine-one of the most-promising trends in current medicine. Except for the appropriate drug used during the treatment, a strong focus is put on the development of effective drug carriers. Among the various materials applied in the production of drug carriers, molecularly imprinted polymers (MIPs) are one of the candidates with great potential for use in theranostics. MIP properties such as chemical and thermal stability, together with capability to integrate with other materials are important in the case of diagnostics and therapy. Moreover, the MIP specificity, which is important for targeted drug delivery and bioimaging of particular cells, is a result of the preparation process, conducted in the presence of the template molecule, which often is the same as the target compound. This review focused on the application of MIPs in theranostics. As a an introduction, the current trends in theranostics are described prior to the characterization of the concept of molecular imprinting technology. Next, a detailed discussion of the construction strategies of MIPs for diagnostics and therapy according to targeting and theranostic approaches is provided. Finally, frontiers and future prospects are presented, stating the direction for further development of this class of materials.

A human VEGF magnetic molecularly imprinted polymer for drug-free anti-angiogenesis and photothermal therapy of tumors

A magnetic molecularly imprinted polymer was developed with an epitope peptide of human VEGF as a template via an epitope blotting technique. As a drug-free agent, the nanoparticles can significantly suppress the proliferation of tumor cells by integrating anti-angiogenesis and photothermotherapy. This work provides a successful example of the design of multimodal antineoplastic drugs.

Synergistic H2O2 self-supplying and NIR-responsive drug delivery nanoplatform for chemodynamic-photothermal-chemotherapy

Developing effectively synergistic multi-mode drug delivery nanoplatform for cancer treatment is of great significance but still challenging. Here, we construct core-shell (CaO₂@Au nanoshells) nanoparticles coated with doxorubicin-loaded hyaluronic acid. The developed platform can be used as synergistic H₂O₂ self-supplying and near-infrared-enhanced reactive oxygen species producer for chemodynamic-photothermal-chemotherapy multi-mode drug delivery. In this platform, the CaO₂ possesses a high capacity of self-supplying H₂O₂ in acidic conditions, while retains desired stability under physiological conditions. The in-situ deposited Au nanoshells not only provide a remarkable photothermal therapy, but function as peroxidase mimics to catalyze H₂O₂ to produce hydroxyl radical to afford highly efficient chemodynamic therapy. Furthermore, the outer layer hyaluronic acid can load doxorubicin and target overexpressed receptor CD44 of cancer cell, meanwhile, trigger release of DOX in photothermal condition and acidic tumor microenvironment. The results of in vitro cell viability and in vivo tumor inhibition indicate that the developed synergistic nanoplatform hold the potential as an efficient strategy for chemodynamic-photothermal-chemotherapy combination therapy of cancer.

Customizable molecular recognition: advancements in design, synthesis, and application of molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) are unlocking the door to synthetic materials that are capable of molecular recognition.

A glycol nanomedicine via metal-coordination supramolecular self-assembly strategy for drug release monitoring and chemo-chemodynamic therapy

A glycol nanomedicine based on metal-coordination supramolecular self-assembly strategy of GluCC (a copper complex of glucose modified coumarin derivative) and a chemotherapeutic agent of doxorubicin (DOX) was successfully developed. In...

Embedded Upconversion Nanoparticles in Magnetic Molecularly Imprinted Polymers for Photodynamic Therapy of Hepatocellular Carcinoma

In this work, high-temperature pyrolysis was used to prepare both the core and shell of lantha-nide-doped UCNPs with lithium yttrium tetrafluoride (LiYF4) to enhance the green luminescence. Merocyanine 540 (MC540)-grafted magnetic nanoparticles were incorporated in the PD-L1 pep-tide-imprinted poly(ethylene-co-vinyl alcohol) particles, which were formed by precipitation in a non-solvent. UCNPs in the non-solvent bath were thus entrapped in the imprinted particles to generate composite nanoparticles for the targeting and photodynamic therapy of PD-L1 in tumor cells. Finally, the in vitro cytotoxicity of the nanoparticles in HepG2 human liver cancer cells was evaluated with the continuous administration of MC540/MNPs@MIPs/UCNPs under irradiation by an NIR laser. To understand the delivery of the UCNP-embedded molecularly imprinted pol-ymers, the intrinsic and extrinsic pathways were also investigated.