Dual Enzyme-Like Performances of PLGA Grafted Maghemite Nanocrystals and Their Synergistic Chemo/Chemodynamic Treatment for Human Lung Adenocarcinoma A549 Cells

Tailoring metal oxide nanozymes for biomedical applications: trends, limitations, and perceptions

Nanomaterials with enzyme-like properties are known as 'nanozymes'. Nanozymes are preferred over natural enzymes due to their nanoscale characteristics and ease of tailoring of their physicochemical properties such as size, structure, composition, surface chemistry, crystal planes, oxygen vacancy, and surface valence state. Interestingly, nanozymes can be precisely controlled to improve their catalytic ability, stability, and specificity which is unattainable by natural enzymes. Therefore, tailor-made nanozymes are being favored over natural enzymes for a range of potential applications and better prospects. In this context, metal oxide nanoparticles with nanozyme-mimicking characteristics are exclusively being used in biomedical sectors and opening new avenues for future nanomedicine. Realising the importance of this emerging area, here, we discuss the mechanistic actions of metal oxide nanozymes along with their key characteristics which affect their enzymatic actions. Further, in this critical review, the recent progress towards the development of point-of-care (POC) diagnostic devices, cancer therapy, drug delivery, advanced antimicrobials/antibiofilm, dental caries, neurodegenerative diseases, and wound healing potential of metal oxide nanozymes is deliberated. The advantages of employing metal oxide nanozymes, their potential limitations in terms of nanotoxicity, and possible prospects for biomedical applications are also discussed with future recommendations.

Cu2+-Citrate-Chitosan Complex Nanoparticles for the Chemodynamic Therapy of Lung Cancer

Lung cancer poses a significant threat to human health. Surgical intervention is the preferred treatment modality for lung cancer, but a large number of patients are deprived of the opportunity for surgery for various reasons and are compelled to undergo radiotherapy and chemotherapy, which entail systemic adverse reactions. In recent years, with the advancement of nanomedicine, chemodynamic therapy (CDT) based on free radicals has been extensively investigated. In this study, we fabricated copper-citrate-chitosan composite nanoparticles (CuCC NPs) by encapsulating copper-citrate complexes with natural chitosan polymers, resulting in a substantial reduction in the biotoxicity of copper ions. The CuCC NPs selectively accumulated in tumor tissues through the enhanced permeability and retention effect (EPR) and gradually degraded within the acidic and glutathione (GSH)-rich microenvironment of the tumor, thereby releasing the loaded copper ions. Through CDT, the copper ions converted the overexpressed hydrogen peroxide (H2O2) in the tumor tissue into hydroxyl radicals (•OH), leading to the eradication of tumor cells. In animal experiments, CuCC NPs exhibited remarkable efficacy in CDT. Further histopathological and hematological analyses demonstrated that CuCC NPs could induce substantial apoptosis in tumor tissues while maintaining an extremely high level of safety.

A sequentially responsive cascade nanoplatform for increasing chemo-chemodynamic therapy

Poly(lactide-co-glycolide) (PLGA) is promising carrier material for drugs delivery in cancer therapy. However, the slow degradation and lack of targeting have greatly limited the clinical effectiveness of PLGA-based nanomedicines. Herein, we fabricated a hybrid nanosystem (3 P @ He/Pt-NPs) comprising of acid-sensitive polymer (mPOE-PLGA), active-targeting polymer (PBA-PLGA) and therapeutic agents (hemin+cisplatin) to combat these problems. In neutral environment, PEGylation can effectively improve the blood stability and circulation time of hybrid nanosystem. After reaching tumor regions, this nanosystem efficiently increased cellular uptake by dePEGylation and PBA-mediated active-targeting. Furthermore, encapsulated hemin could catalyze the oxygen bubbles generation, which remarkably increasing the drugs release rate. Subsequently, hybrid particles produced a higher cell-killing effect to lung cancer cells (A549) by the combination therapy (chemotherapy and chemodynamic therapy (CDT)). Importantly, cisplatin further amplified CDT effect by inducing H₂O₂ regeneration owing to the cascade enzymatic reactions, while hemin decreased intracellular glutathione (GSH) level, resulting in a low detoxification effect to cisplatin. Thus, hybrid particles could efficiently inhibit drug-resistant tumor growth and the inhibition rate reached 83.2%. Overall, this hybrid polymer nanosystem improve the drawbacks of PLGA-based nanocarriers, and can realize a cascading enhanced tumor treatment.

A flexible visual detection of calcium peroxide in flour employing enhanced catalytic activity of heterogeneous catalysts binary copper trapped silica-layered magnetite nanozyme

Herein, a novel heterogeneous nanozyme with peroxidase (POD)-like activity was conducted to achieve ultrasensitive visual detection of calcium peroxide (CaO2) in flour by the assembly of binary copper-trapped mesoporous silica layer coated magnetite nanoparticles (Fe3O4 @SiO2 @CuO NPs). The prepared nanozymes were characterized using HRTEM, SEM, FT-IR, XRD, DLS, and EIS, which displayed a dispersed core-shell structure with a uniform diameter of approximately 100 nm. The nanozymes exhibited remarkable and stable POD-like activity in a wide range of pH values, incubation temperature, and reaction time, and the optimum catalytic activity was obtained at pH 3.6, 37 °C, and 10 min. The quantification range of CaO2 of this method is 0.1-5 mM with a limit as low as 5.6 × 10-3 mM, and it is not affected by multiple interferences. In conclusion, this detection method is sensitive, stable, low-cost, and simple to operate, so it has broad application prospects in the detection of food additives such as CaO2.

Anti-Tumor Effect and Drug Delivery of Biomimetic Exosomes Nanoplatform Loading with Paclitaxel (PTX) for Treating Lung Adenocarcinoma

This study constructed an exosome (Exo) nanomedicine with the ability to actively penetrate into lung tumor tissue, in order to improve the anti-tumor effect of paclitaxel (PTX). For reaching this goal A549 lung adenocarcinoma cells were employed. The exosomes were collected by gradient centrifugation, and the Exo/PTX was prepared after targeted modification. Then the in vitro properties and in vivo tumor inhibitory effects of Exo/PTX were then characterized and evaluated. to conduct in vitro and in vivo study. The prepared Exo/PTX had a particle size of about 100 nm, and had a saucer-like double-layer membrane structure, which had a high encapsulation efficiency and drug loading. in vitro studies have shown that Exo/PTX can be largely taken up by lung cancer cells, thereby enhancing the drug’s effects on promoting apoptosis. The results of in vivo experiments showed that Exo/PTX can effectively inhibit the growth of tumor tissue. The results of this study showed that using exosome for drug delivery of PTX can increase the efficacy and decrease the drug toxicity and side effects.

Dual-Targeted Fe₃O₄@MnO₂ Nanoflowers for Magnetic Resonance Imaging-Guided Photothermal-Enhanced Chemodynamic/Chemotherapy for Tumor

The construction of high-efficiency tumor theranostic platform will be of great interest in the treatment of cancer patients; however, significant challenges are associated with developing such a platform. In this study, we developed high-efficiency nanotheranostic agent based on ferroferric oxide, manganese dioxide, hyaluronic acid and doxorubicin (FMDH-D NPs) for dual targeting and imaging guided synergetic photothermal-enhanced chemodynamic/chemotherapy for cancer, which improved the specific uptake of drugs at tumor site by the dual action of CD44 ligand hyaluronic acid and magnetic nanoparticles guided by magnetic force. Under the acidic microenvironment of cancer cells, FMDH-D could be decomposed into Mn²⁺ and Fe²⁺ to generate •OH radicals by triggering a Fenton-like reaction and responsively releasing doxorubicin to kill cancer cells. Meanwhile, alleviating tumor hypoxia improved the efficacy of chemotherapy in tumors. The photothermal properties of FMDH generated high temperatures, which further accelerated the generation of reactive oxygen species, and enhanced effects of chemodynamic therapy. Furthermore, FMDH-D NPs proved to be excellent T₁/T₂-weighted magnetic resonance imaging contrast agents for monitoring the tumor location. These results confirmed the considerable potential of FMDH-D NPs in a highly efficient synergistic therapy platform for cancer treatment.

Nanobead-Based Screening Method for Antibody Pairing of Dengue Virus Nonstructural Protein-1

Dengue fever is a classic mosquito viral disease. Dengue virus non-structural protein-1 as a membrane-associated homologous dimer anchored to the surface of infected cells and also secreted into the blood. The nonstructural protein-1 levels are related to disease severity, and the presence of nonstructural protein-1 secreted from cells to the serum of people infected with the dengue virus is an early marker of infection. Paired antibodies are key in the establishment of rapid detection technology. In this study, the prepared recombinant nonstructural protein-1 protein of dengue virus serotype 3 was purified by the prokaryotic expression, and prepared monoclonal antibodies by cell fusion. A method for paired antibody screening was established based on the N-hydroxy succinimide-nanobeads and the prepared monoclonal antibodies. A simple and rapid point-of-care system integrating the paired antibodies and lateral flow assay was established to verify the screened antibody pairs. The results confirmed that the antibody pair screening method based on N-hydroxy succinimide-nanobeads is feasible.