Zeolitic Imidazolate Framework-8 as pH-Sensitive Nanocarrier for "Arsenic Trioxide" Drug Delivery

Can arsenic do anything good? Arsenic nanodrugs in the fight against cancer - last decade review

Arsenic has been an element of great interest among scientists for many years as it is a widespread metalloid in our ecosystem. Arsenic is mostly recognized with negative connotations due to its toxicity. Surely, most of us know that a long time ago, arsenic trioxide was used in medicine to treat, mainly, skin diseases. However, not everyone knows about its very wide and promising use in the treatment of cancer. Initially, in the seventies, it was used to treat leukemia, but new technological possibilities and the development of nanotechnology have made it possible to use arsenic trioxide for the treatment of solid tumours. The most toxic arsenic compound - arsenic trioxide - as the basis of anticancer drugs in which they function as a component of nanoparticles is used in the fight against various types of cancer. This review aims to present the current solutions in various cancer treatment using arsenic compounds with different binding motifs and methods of preparation to create targeted nanoparticles, nanodiamonds, nanohybrids, nanodrugs, or nanovehicles.

ZIF-8 Nanoparticle: A Valuable Tool for Improving Gene Delivery in Sperm-Mediated Gene Transfer

Metal-organic frameworks (MOFs) are porous materials with unique characteristics that make them well-suited for drug delivery and gene therapy applications. Among the MOFs, zeolitic imidazolate framework-8 (ZIF-8) has emerged as a promising candidate for delivering exogenous DNA into cells. However, the potential of ZIF-8 as a vector for sperm-mediated gene transfer (SMGT) has not yet been thoroughly explored.This investigation aimed to explore the potential of ZIF-8 as a vector for enhancing genetic transfer and transgenesis rates by delivering exogenous DNA into sperm cells. To test this hypothesis, we employed ZIF-8 to deliver a plasmid expressing green fluorescent protein (GFP) into mouse sperm cells and evaluated the efficiency of DNA uptake. Our findings demonstrate that ZIF-8 can efficiently load and deliver exogenous DNA into mouse sperm cells, increasing GFP expression in vitro. These results suggest that ZIF-8 is a valuable tool for enhancing genetic transfer in SMGT, with important implications for developing genetically modified animals for research and commercial purposes. Additionally, our study highlights the potential of ZIF-8 as a novel class of vectors for gene delivery in reproductive biology.Overall, our study provides a foundation for further research into using ZIF-8 and other MOFs as gene delivery systems in reproductive biology and underscores the potential of these materials as promising vectors for gene therapy and drug delivery.

Recent Advances in Metal-Organic-Framework-Based Nanocarriers for Controllable Drug Delivery and Release

Metal-organic frameworks (MOFs) have a good designability, a well-defined pore, stimulus responsiveness, a high surface area, and a controllable morphology. Up to now, various MOFs have been widely used as nanocarriers and have attracted lots of attention in the field of drug delivery and release because of their good biocompatibility and high-drug-loading capacity. Herein, we provide a comprehensive summary of MOF-based nanocarriers for drug delivery and release over the last five years. Meanwhile, some representative examples are highlighted in detail according to four categories, including the University of Oslo MOFs, Fe-MOFs, cyclodextrin MOFs, and other MOFs. Moreover, the opportunities and challenges of MOF-based smart delivery vehicles are discussed. We hope that this review will be helpful for researchers to understand the recent developments and challenges of MOF-based drug-delivery systems.

Dissolution and Biological Assessment of Cancer-Targeting Nano-ZIF-8 in Zebrafish Embryos

Cancer-targeting nanotherapeutics offer promising opportunities for selective delivery of cytotoxic chemotherapeutics to cancer cells. However, the understanding of dissolution behavior and safety profiles of such nanotherapeutics is scarce. In this study, we report the dissolution profile of a cancer-targeting nanotherapeutic, gemcitabine (GEM) encapsulated within RGD-functionalized zeolitic imidazolate framework-8 (GEM⊂RGD@nZIF-8), in dissolution media having pH = 6.0 and 7.4. GEM⊂RGD@nZIF-8 was not only responsive in acidic media (pH = 6.0) but also able to sustain the dissolution rate (57.6%) after 48 h compared to non-targeting nanotherapeutic GEM⊂nZIF-8 (76%). This was reflected by the f₂ value of 36.1, which indicated a difference in the dissolution behaviors of GEM⊂RGD@nZIF-8 and GEM⊂nZIF-8 in acidic media compared to those in neutral media (pH = 7.4). A dissolution kinetic study showed that the GEM release mechanism from GEM⊂RGD@nZIF-8 followed the Higuchi model. In comparison to a non-targeting nanotherapeutic, the cancer-targeting nanotherapeutic exhibited an enhanced permeability rate in healthy zebrafish embryos but did not induce lethality to 50% of the embryos (LC₅₀ > 250 μg mL^-1) with significantly improved survivability (75%) after 96 h of incubation. Monitoring malformation showed minimal adverse effects with only 8.3% of edema at 62.5 μg mL^-1. This study indicates that cancer-targeting GEM⊂RGD@nZIF, with its pH-responsive behavior for sustaining chemotherapeutic dissolution in a physiologically relevant environment and its non-toxicity toward the healthy embryos within the tested concentrations, has considerable potential for use in cancer treatment.

Stability of ZIF-8 Nanoparticles in Most Common Cell Culture Media

Zeolite imidazolate framework-8 (ZIF-8) is a promising platform for drug delivery, and information regarding the stability of ZIF-8 nanoparticles in cell culture media is essential for proper interpretation of in vitro experimental results. In this work, we report a quantitative investigation of the ZIF-8 nanoparticle's stability in most common cell culture media. To this purpose, ZIF-8 nanoparticles containing sterically shielded nitroxide probes with high resistance to reduction were synthesized and studied using electron paramagnetic resonance (EPR). The degradation of ZIF-8 in cell media was monitored by tracking the cargo leakage. It was shown that nanoparticles degrade at least partially in all studied media, although the degree of cargo leakage varies widely. We found a strong correlation between the amount of escaped cargo and total concentration of amino acids in the environment. We also established the role of individual amino acids in ZIF-8 degradation. Finally, 2-methylimidazole preliminary dissolved in cell culture media partially inhibits the degradation of ZIF-8 nanoparticles. The guidelines for choosing the proper cell culture medium for the in vitro study of ZIF-8 nanoparticles have been formulated.

Reticular Nanoscience: Bottom-Up Assembly Nanotechnology

The chemistry of metal-organic and covalent organic frameworks (MOFs and COFs) is perhaps the most diverse and inclusive among the chemical sciences, and yet it can be radically expanded by blending it with nanotechnology. The result is reticular nanoscience, an area of reticular chemistry that has an immense potential in virtually any technological field. In this perspective, we explore the extension of such an interdisciplinary reach by surveying the explored and unexplored possibilities that framework nanoparticles can offer. We localize these unique nanosized reticular materials at the juncture between the molecular and the macroscopic worlds, and describe the resulting synthetic and analytical chemistry, which is fundamentally different from conventional frameworks. Such differences are mirrored in the properties that reticular nanoparticles exhibit, which we described while referring to the present state-of-the-art and future promising applications in medicine, catalysis, energy-related applications, and sensors. Finally, the bottom-up approach of reticular nanoscience, inspired by nature, is brought to its full extension by introducing the concept of augmented reticular chemistry. Its approach departs from a single-particle scale to reach higher mesoscopic and even macroscopic dimensions, where framework nanoparticles become building units themselves and the resulting supermaterials approach new levels of sophistication of structures and properties.

Current Advances of Nanomedicines Delivering Arsenic Trioxide for Enhanced Tumor Therapy

Arsenic trioxide (ATO) is one of the first-line chemotherapeutic drugs for acute promyelocytic leukemia. Its anti-cancer activities against various human neoplastic diseases have been extensively studied. However, the clinical use of ATO for solid tumors is limited, and these limitations are because of severe systemic toxicity, low bioavailability, and quick renal elimination before it reaches the target site. Although without much success, several efforts have been made to boost ATO bioavailability toward solid tumors without raising its dose. It has been found that nanomedicines have various advantages for drug delivery, including increased bioavailability, effectiveness, dose-response, targeting capabilities, and safety as compared to traditional drugs. Therefore, nanotechnology to deliver ATO to solid tumors is the main topic of this review, which outlines the previous and present medical applications of ATO. We also summarised ATO anti-cancer mechanisms, limitations, and outcomes of combinatorial treatment with chemo agents. As a result, we strongly recommend conducting pre-clinical and clinical studies of ATO, especially nano-system-based ones that might lead to a novel combination therapy for cancer treatment with high efficacy, bioavailability, and low toxicity for cancer patients.

Mineral medicine: from traditional drugs to multifunctional delivery systems

Mineral drugs are an important constituent of traditional Chinese medicine (TCM). Taking minerals that contain heavy metals as drugs is a very national characteristic part of TCM. However, the safety and scientific nature of mineral drugs are controversial owing to their heavy metals and strong toxicity. In 2000, the Food and Drug Administration (FDA) authorized arsenic trioxide (ATO) as first-line therapy for acute promyelocytic leukemia. This makes the development and utilization of mineral drugs become a research hotspot. The development of nanomedicine has found a great prospect of mineral drugs in nano-delivery carriers. And that will hold promise to address the numerous biological barriers facing mineral drug formulations. However, the studies on mineral drugs in the delivery system are few at present. There is also a lack of a detailed description of mineral drug delivery systems. In this review, the advanced strategies of mineral drug delivery systems in tumor therapy are summarized. In addition, the therapeutic advantages and research progress of novel mineral drug delivery systems are also discussed. Here, we hope that this will provide a useful reference for the design and application of new mineral drug delivery systems.

Effects of Zeolite as a Drug Delivery System on Cancer Therapy: A Systematic Review

Zeolites and zeolitic imidazolate frameworks (ZIFs) are widely studied as drug carrying nanoplatforms to enhance the specificity and efficacy of traditional anticancer drugs. At present, there is no other systematic review that assesses the potency of zeolites/ZIFs as anticancer drug carriers. Due to the porous nature and inherent pH-sensitive properties of zeolites/ZIFs, the compounds can entrap and selectively release anticancer drugs into the acidic tumor microenvironment. Therefore, it is valuable to provide a comprehensive overview of available evidence on the topic to identify the benefits of the compound as well as potential gaps in knowledge. The purpose of this study was to evaluate the potential therapeutic applications of zeolites/ZIFs as drug delivery systems delivering doxorubicin (DOX), 5-fluorouracil (5-FU), curcumin, cisplatin, and miR-34a. Following PRISMA guidelines, an exhaustive search of PubMed, Scopus, Embase, and Web of Science was conducted. No language or time limitations were used up to 25th August 2021. Only full text articles were selected that pertained to the usage of zeolites/ZIFs in delivering anticancer drugs. Initially, 1279 studies were identified, of which 572 duplicate records were excluded. After screening for the title, abstract, and full texts, 53 articles remained and were included in the qualitative synthesis. An Inter-Rater Reliability (IRR) test, which included a percent user agreement and reliability percent, was conducted for the 53 articles. The included studies suggest that anticancer drug-incorporated zeolites/ZIFs can be used as alternative treatment options to enhance the efficacy of cancer treatment by mitigating the drawbacks of drugs under conventional treatment.

Immunotherapy of tumors by tailored nano-zeolitic imidazolate framework protected biopharmaceuticals

In cancer immunotherapy, antibodies have acquired rapidly increasing attention due to their sustained immune effect by target specific delivery without any adverse effects. Among many recent strategies, controlled delivery of monoclonal antibodies, check point inhibitor storage and tumor-specific targeted delivery have enabled biodegradable immunotherapeutic delivery via translation of tailored nano-zeolitic imidazolate frameworks (ZIFs) with encapsulated biopharmaceuticals. In addition, a robust antitumor immunity was developed by anti-programmed death ligand-1 (anti-PD-L1) antibody delivery by ZIF-8 with polyethylene glycol (PEG) protection by forming a multiple immunoregulatory system. The unique biorecognition capability of antibodies, encapsulated in ZIFs, was recognized by using growth on different substrates, such as bioconjugates on gold nanorods, to transform them into plasmonic nanobiosensors with sensitivity of the refractive index profile of surface plasmons to track the conjugating antibody. Herein, we have discussed the mechanistic window of antibody delivery-based immunotherapy via the encapsulation of antibodies within ZIFs as an emerging tool for protecting biopharmaceuticals from the complex cellular microenvironment and hyperthermia to enable an antitumor immune response. To fully achieve the potential of antibodies upon ZIF encapsulation, more endeavors should be undertaken in the biodegradable engineering of ZIF-surfaces via forming cellular or polymeric layers to gain higher in vivo circulation time without inhibiting endocytosis by tumor cells. The possible future prognosis for achieving ZIF-protected biocompatible and biodegradable immunotherapeutic antibody delivery systems of therapeutic significance is discussed.

Current status and future prospects of nanomedicine for arsenic trioxide delivery to solid tumors

Despite having a rich history as a poison, arsenic and its compounds have also gained a great reputation as promising anticancer drugs. As a pioneer, arsenic trioxide has been approved for the treatment of acute promyelocytic leukemia. Many in vitro studies suggested that arsenic trioxide could also be used in the treatment of solid tumors. However, the transition from bench to bedside turned out to be challenging, especially in terms of the drug bioavailability and concentration reaching tumor tissues. To address these issues, nanomedicine tools have been proposed. As nanocarriers of arsenic trioxide, various materials have been examined including liposomes, polymer, and inorganic nanoparticles, and many other materials. This review gives an overview of the existing strategies of delivery of arsenic trioxide in cancer treatment with a focus on the drug encapsulation approaches and medicinal impact in the treatment of solid tumors. It focuses on the progress in the last years and gives an outlook and suggestions for further improvements including theragnostic approaches and targeted delivery.

A drug delivery system based on nanocomposites constructed from metal-organic frameworks and Mn3O4 nanoparticles: Preparation and physicochemical characterization for BT-474 and MCF-7 cancer cells

An integrated nanocomposite system comprising of manganese oxide (Mn₃O₄) nanoparticles, functioning as a tumor diagnostic agent, in conjunction with polyacrylic acid (PAA) and ZIF-8, as pH-sensitive drug delivery agents, and methotrexate (MTX), operating as a tumor biomarker and a therapeutic agent (dual mechanism of action), is applied for both diagnostic intentions and controlled delivery of the drug. Physicochemical characteristics of the constructed system, Mn₃O₄@PAA@ZIF-8/MTX, are investigated by several methods, including X-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and electrochemical techniques. The in-vitro magnetic resonance imaging measurements was performed to show the efficiency of Mn₃O₄@PAA@ZIF-8 nanocomposite as a contrast agent where a relaxivity (r₁) of 3.3 mM^-1 s^-1 is found. The loading ratio was found as 161 % which is four times larger than the value obtained for Mn₃O₄@PAA system in the same conditions, indicating high capability of the system for MTX delivery. The application of the nanocomposite as a dual pH-sensitive nanocarrier for MTX is studied through in-vitro drug release experiments at pHs of 5.4, 6.8 and 7.4. Interestingly, the results show that a large amount of loaded MTX drug (53 %) is released from the system during incubation and dialysis at pH 5.4, compared with that (20 % and 15 %), respectively, released at pHs 6.8 and 7.4 at the same conditions. The affinity of Mn₃O₄@PAA@ZIF-8/MTX nanocomposite for capturing of BT-474 and MCF-7 cancer cells was evaluated via impedance spectroscopy measurements. The results show that GC-Mn₃O₄@PAA@ZIF-8/MTX electrode captures the BT-474 and MCF-7 cancer cells, respectively, by factors of ∼2 and 196 compared with L929 normal cells. This affinity also shows the high selectivity of the system for MCF-7 cancer cells compared with BT-474.

Capture and Decomposition of the Nerve Agent Simulant, DMCP, Using the Zeolitic Imidazolate Framework (ZIF-8)

Understanding mechanisms of decontamination of chemical warfare agents (CWA) is an area of intense research aimed at developing new filtration materials to protect soldiers and civilians in case of state-sponsored or terrorist attack. In this study, we employed complementary structural, chemical, and dynamic probes and in situ data collection, to elucidate the complex chemistry, capture, and decomposition of the CWA simulant, dimethyl chlorophosphonate (DMCP). Our work reveals key details of the reactive adsorption of DMCP and demonstrates the versatility of zeolitic imidazolate framework (ZIF-8) as a plausible material for CWA capture and decomposition. The in situ synchrotron-based powder X-ray diffraction (PXRD) and pair distribution function (PDF) studies, combined with Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), zinc K-edge X-ray absorption near edge structure (XANES), and Raman spectroscopies, showed that the unique structure, chemical state, and topology of ZIF-8 enable accessibility, adsorption, and hydrolysis of DMCP into the pores and revealed the importance of linker chemistry and Zn²⁺ sites for nerve agent decomposition. DMCP decontamination and decomposition product(s) formation were observed by thermogravimetric analysis, FT-IR spectroscopy, and phosphorus (P) K-edge XANES studies. Differential PDF analysis indicated that the average structure of ZIF-8 (at the 30 Å scale) remains unchanged after DMCP dosing and provided information on the dynamics of interactions of DMCP with the ZIF-8 framework. Using in situ PXRD and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), we showed that nearly 90% regeneration of the ZIF-8 structure and complete liberation of DMCP and decomposition products occur upon heating.

Tumor targeted self-synergistic nanoplatforms for arsenic-sensitized photodynamic therapy

Development of antitumor agents with high efficiency and low toxicity is one of the most important goals for biomedical research. However, most traditional therapeutic strategies were limited due to their non-specificity and abnormal tumor microenvironments, causing a poor therapeutic efficiency and severe side effects. In this paper, a tumor targeted self-synergistic nanoplatform (designated as PAO@PCN@HA) was developed for chemotherapy sensitized photodynamic therapy (PDT) against hypoxic tumors. The efficient drug loading of phenylarsine oxide (PAO) in porphyrinic metal organic framework of PCN-224 as well as the surface modification of hyaluronic acid (HA) improved the targeted drug delivery and reduced the side effects of PAO at the therapeutic dose. Particularly, PAO as an arsenical-based chemotherapeutic agent could not only induce cell apoptosis by generating reactive oxygen species (ROS), but also regulate tumor microenvironments to improve the PDT effect of PCN-224 by mitigating hypoxia and consuming cellular GSH. Both in vitro and in vivo investigations confirmed an effective self-synergy of PAO@PCN@HA in hypoxic tumor therapy with a low systemic toxicity. This integration of microenvironment adjustment with tumor targeted self-synergistic mechanism might provide a new insight for the development of arsenic-based antitumor strategy for clinical applications.

Synthesis and modification of ZIF-8 and its application in drug delivery and tumor therapy

Metal–organic frameworks have the properties of high porosity, variable pore sizes, and easy modification as drug delivery systems. In particular, ZIF-8 based on Zn²⁺ has been extensively studied in the medical field due to its low toxicity and good biocompatibility. This review introduces the preparation and functional modification of ZIF-8, and its application in drug delivery, focusing on the single-stimulus and multi-stimulus response release of drugs in ZIF-8 materials, the integrated role of diagnosis and treatment with ZIF-8 in cancer treatment, and its application in the synergistic therapy of multiple cancer treatment methods. We summarize the latest developments of ZIF-8 in the field of drug delivery and tumor therapy, and present the main challenges that remain to be resolved in the ZIF-8 drug delivery system.

Synthesis and modification of ZIF-8 and its application in drug delivery, stimulus response-controlled drug release and tumor therapy.

Zeolitic Imidazolate Framework-8 as pH-Sensitive Nanocarrier for "Arsenic Trioxide" Drug Delivery

Previous results revealed that arsenic trioxide might be used as promising therapeutic agent for the treatment of some solid tumours as atypical teratoid rhabdoid tumours (ATRT). However, in order to become an approved drug for solid tumour treatment, the active formulation has to get more efficient and feasible-but at the same time less toxic. One of the possibilities to achieve this dichotomy is to use nanomedicine tools. Herein, we report on the Zn-based metal-organic framework ZIF-8 (Zeolitic Imidazolate Framework-8) which turned out to be a promising candidate for the delivery of AsIII species. It conjointly features a high drug loading capacity and a prominent pH-triggered release behaviour. AsIII -loaded ZIF-8 nanoparticles coated and non-coated with polyethylene glycol were studied by XRPD, IR, Raman, TGA, TEM, EDX, CHN-elemental analysis, sorption analysis and ICP-OES, and their cytotoxicity was evaluated in vitro.