Efficient drug delivery of 5-fluorouracil by a biocompatible Zn-metal–organic framework nanostructure and anti-liver cancer activity study

Size-tunable nanogels for cascaded release of metronidazole and chemotherapeutic agents to combat Fusobacterium nucleatum-infected colorectal cancer

Bacteria play important roles in tumor formation, growth and metastasis through downregulating immune response and initiating drug resistance. Herein, size-tunable nanogels (NGs) have been developed to address the existing size paradox in tumor accumulation, intratumoral penetration and intracellular release of therapeutics for the treatment of Fusobacterium nucleatum (F. nucleatum)-infected colorectal cancer. Zinc-imidazolate frameworks with doxorubicin (DOX) loading and folate grafting (f-ZIFD) were mixed with metronidazole (MET) and encapsulated in NGs through thiol-ene click crosslinking of sulfhydryl hyaluronan, sulfhydryl alginate and 4-arm poly(ethylene glycol) acrylate. Hyaluronidase-initiated matrix degradation causes NG swelling to release sufficient MET and maintains a large size for an extended time period, and the gradually discharged f-ZIFD nanoparticles (NPs) from NGs exhibit acid-responsive intracellular release of DOX after folate-mediated internalization into tumor cells. The encapsulation into NGs significantly enhances the bioavailability and increases half-lives of MET and DOX by around 20 times. In the F. nucleatum-infected tumor model, the extended retention of swollen NGs and the efficient tumor infiltration and cellular uptake of the discharged f-ZIFD NPs cause 6 times higher DOX levels in tumors than that of free DOX administration. F. nucleatum promotes tumor cell proliferation and tumor growth, and the cascaded releases of MET and f-ZIFD NPs eliminate F. nucleatum to effectively inhibit tumor growth with a significant extension of animal survival. Thus, the hyaluronidase-mediated NG expansion and dual-responsive cascaded drug release have overcome challenges in the release regimen and size paradox of drug delivery carriers to combat bacteria-infected cancer.

Stimuli-Responsive Design of Metal-Organic Frameworks for Cancer Theranostics: Current Challenges and Future Perspective

Scientific fraternity revealed the potential of stimuli-responsive nanotherapeutics for cancer treatment that aids in tackling the major restrictions of traditionally reported drug delivery systems. Among stimuli-responsive inorganic nanomaterials, metal-organic frameworks (MOFs) have transpired as unique porous materials displaying resilient structures and diverse applications in cancer theranostics. Mainly, it demonstrates tailorable porosity, versatile chemical configuration, tunable size and shape, and feasible surface functionalization, etc. The present review provides insights into the design of stimuli-responsive multifunctional MOFs for targeted drug delivery and bioimaging for effective cancer therapy. Initially, the concept of cancer, traditional cancer treatment, background of MOFs, and approaches for MOFs synthesis have been discussed. After this, applications of stimuli-responsive multifunctional MOFs-assisted nanostructures that include pH, light, ions, temperature, magnetic, redox, ATP, and others for targeted drug delivery and bioimaging in cancer have been thoroughly discussed. As an outcome, the designed multifunctional MOFs showed an alteration in properties due to the exogenous and endogenous stimuli that are beneficial for drug release and bioimaging. The several reported types of stimuli-responsive surface-modified MOFs revealed good biocompatibility to normal cells, promising drug loading capability, target-specific delivery of anticancer drugs into cancerous cells, etc. Despite substantial progress in this field, certain crucial issues need to be addressed to reap the clinical benefits of multifunctional MOFs. Specifically, the toxicological compatibility and biodegradability of the building blocks of MOFs demand a thorough evaluation. Moreover, the investigation of sustainable and greener synthesis methods is of the utmost importance. Also, the low flexibility, off-target accumulation, and compromised pharmacokinetic profile of stimuli-responsive MOFs have attracted keen attention. In conclusion, the surface-modified nanosized design of inorganic diverse stimuli-sensitive MOFs demonstrated great potential for targeted drug delivery and bioimaging in different kinds of cancers. In the future, the preference for stimuli-triggered MOFs will open a new frontier for cancer theranostic applications.

A reliable QSPR model for predicting drug release rate from metal-organic frameworks: a simple and robust drug delivery approach

During the drug release process, the drug is transferred from the starting point in the drug delivery system to the surface, and then to the release medium. Metal-organic frameworks (MOFs) potentially have unique features to be utilized as promising carriers for drug delivery, due to their suitable pore size, high surface area, and structural flexibility. The loading and release of various therapeutic drugs through the MOFs are effectively accomplished due to their tunable inorganic clusters and organic ligands. Since the drug release rate percentage (RES%) is a significant concern, a quantitative structure-property relationship (QSPR) method was applied to achieve an accurate model predicting the drug release rate from MOFs. Structure-based descriptors, including the number of nitrogen and oxygen atoms, along with two other adjusted descriptors, were applied for obtaining the best multilinear regression (BMLR) model. Drug release rates from 67 MOFs were applied to provide a precise model. The coefficients of determination (R2) for the training and test sets obtained were both 0.9999. The root mean square error for prediction (RMSEP) of the RES% values for the training and test sets were 0.006 and 0.005, respectively. To examine the precision of the model, external validation was performed through a set of new observations, which demonstrated that the model works to a satisfactory degree.

A 2D Porous Zinc-Organic Framework Platform for Loading of 5-Fluorouracil

A hydrostable 2D Zn-based MOF, {[Zn(5-PIA)(imbm)]·2H2O}n (1) (5-H2PIA = 5-propoxy-isophthalic acid, imbm = 1,4-di(1H-imidazol-1-yl)benzene), was synthesized and structurally characterized. Complex 1 shows good water and thermal stability based on the TGA and PXRD analyses and displays a 2D framework with 1D channels of 4.8 × 13.8 and 10.0 × 8.3 Å2 along the a axis. The 5-fluorouracil (5-FU) payload in activated complex 1 (complex 1a) is 19.3 wt%, and the cumulative release value of 5-FU at 120 h was about 70.04% in PBS (pH 7.4) at 310 K. In vitro MTT assays did not reveal any cytotoxic effect of NIH-3T3 and HEK-293 cells when the concentration of 1 was below 500 μg/mL and 5 μg/mL, respectively. No morphological abnormalities were observed on zebrafish exposed to complex 1.

MOF-801 as a Nanoporous Water-Based Carrier System for In Situ Encapsulation and Sustained Release of 5-FU for Effective Cancer Therapy

Nanoporous metal-organic frameworks (MOFs) have been gaining a reputation for their drug delivery applications. In the current work, MOF-801 was successfully prepared by a facile, cost-efficient, and environmentally friendly approach through the reaction of ZrCl₄ and fumaric acid as organic linkers to deliver 5-fluorouracil (5-FU). The prepared nanostructure was fully characterized by a series of analytical techniques including Fourier transform infrared spectroscopy, powder X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV-vis spectroscopy, ¹H NMR spectroscopy, thermogravimetric analysis, high-performance liquid chromatography, and Brunauer-Emmett-Teller analysis. MOF-801 could be used for the delivery of the anticancer drug 5-FU due to its high surface area, suitable pore size, and biocompatible ingredients. Based on in vitro loading and release studies, a high 5-FU loading capacity and pH-dependent drug release behavior were observed. Moreover, the interactions between the structure of MOFs and 5-FU were investigated through Monte Carlo simulation calculations. An in vitro cytotoxicity test was done, and the results indicated that 5-FU@MOF-801 was more potent than 5-FU on SW480 cancerous cells, indicating the highlighted role of this drug delivery system. Finally, the kinetics of drug release was investigated.

Porous Cu-MOF nanostructures with anticancer properties prepared by a controllable ultrasound-assisted reverse micelle synthesis of Cu-MOF

The ultrasonic assisted reverse micelle method (UARM) was used to synthesize Cu-MOF from Cu(NO3)2·3H2O and 2,6-pyridine dicarboxylic acid in a 1:1 molar proportion. It has been characterized using FT-IR, XRD, nitrogen adsorption analysis, SEM and TEM-EDX. The morphology of Cu-MOFs was spherical, with an average particle size distribution of less than 100 nm. Using BET analysis, the surface area of Cu-MOF was found to be 284.94 m2/g. The porous morphology of Cu-MOF was also suggested by SEM and TEM analyses. It has anticancer properties against MCF-7 breast cancer cells. Cytotoxicity testing was performed on MCF-7 breast cancer cells using the MTT cell viability assay, and cell proliferation and viability were found to be approximately 24% higher than the control.

Effectiveness of 5-Fluorouracil and gemcitabine hydrochloride loaded iron‑based chitosan-coated MIL-100 composite as an advanced, biocompatible, pH-sensitive and smart drug delivery system on breast cancer therapy

This study was planned to evolve the bioavailability and therapeutic efficiency of Gemcitabine (GEM) and 5-Fluorouracil with decreased side effects using MIL-100 nano-composite as carrier. Impregnation approach was used for encapsulation of 5-Fluorouracil alone and with GEM inside the MIL-100. The formed 5-Fluorouracil@MIL-100 and 5-Fluorouracil-GEM@MIL-100 were then coated with chitosan, sequentially chelated with iron(III) and conjugated with quercetin, eventually obtaining a multifunctional MIL-100 nanocarrier. The hybrid nanocarrier nascency was verified by different characterization results. pH-sensitive releases of 5-Fluorouracil and GEM were observed because of the inherent pH-dependent stability of MIL-100. Additionally, we evaluated the anti-cancer activity of these nanocarriers through WST-1 analysis and acridine orange staining in MCF-7 human breast cancer and HUVEC control cell lines. Our findings showed that all nanocarriers exhibited anti-cancer activity and induced apoptosis in MCF-7 cells. However, 5-Fluorouracil@MIL-100 and chitosan-coated 5-Fluorouracil@MIL-100 with quercetin were more effective than other nanocarriers in MCF-7 cells (p < 0.05). Moreover, we observed cytotoxicity in HUVEC cells due to the adverse side effects of chemotherapy drugs. However, chitosan coated nanocarriers with quercetin were less toxic on HUVEC cells at particularly 1 µg/mL. Therefore, MIL-100 could be used for a promising chemotherapeutic drugs delivery and chitosan coated drugs with quercetin could be useful for reducing toxicity on normal cells.

Pore engineering of biomolecule-based metal–organic framework nanocarriers for improving loading and release of paclitaxel

There has been growing interest in employing metal–organic frameworks (MOFs) incorporated with biomolecules, known as b-MOFs, in biomedical applications.

Zinc-Based Metal-Organic Frameworks in Drug Delivery, Cell Imaging, and Sensing

The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs' chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions.

pH and H2S Dual-Responsive Magnetic Metal-Organic Frameworks for Controlling the Release of 5-Fluorouracil

Along with the increasing cancer incidence, developing suitable drug delivery systems (DDSs) is becoming urgent to control drug release and further enhance therapeutic efficiency. Herein, a Fe-Zn bimetallic MOF-derived ferromagnetic nanomaterial was synthesized by a one-step method. The successful preparation of ferromagnetic Fe-ZIF-8 was verified by scanning electron microscopy, powder X-ray diffraction, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, and physical property measurement system characterizations. Furthermore, the release behaviors of 5-FU from the ferromagnetic carrier were investigated in a simulative cancer microenvironment of PBS buffer solution (PBS = phosphate-buffered saline, pH = 5.8) and NaHS solution. The vehicle in PBS solution of pH = 5.8 and NaHS solution of 500 μM can rapidly release 5-FU with the cumulative release percentages of 68 and 36%, respectively, within two hundred minutes. The release mechanism in the weak acid environment can be mainly attributed to the decomposition of the Fe-ZIF-8. However, the strong interaction between Zn and Fe atoms in Fe-ZIF-8 and the S atom in H₂S plays an important role in the release process in the simulated H₂S cancer microenvironment. The investigation of release kinetic models indicates that the 5-FU release in the PBS solutions and NaHS solution of 500 μM can be accurately fitted by a second-degree polynomial model and first-order model, respectively. In addition, the decomposition products, zinc, iron, and 2-MeIM, are endogenous and show low toxicity values [LD₅₀ (Zn) = 0.35 g·kg^-1, LD₅₀ (Fe) = 30 g·kg^-1, and LD₅₀ (2-MeIM) = 1.4 g·kg^-1]. Therefore, the low-toxicity, pH and H₂S dual-stimuli-responsive, and ferromagnetic nature make the obtained Fe-ZIF-8 an ideal candidate in the field of bioactive molecule delivery.

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.

Zinc-based metal-organic frameworks as nontoxic and biodegradable platforms for biomedical applications: review study

Development of biomedical systems for controllable drug delivery systems and construction of biosensors is imperative to reduce side effects of common treatment techniques and enhance the therapeutic efficacy. To address this issue, metal-organic frameworks (MOFs) as hybrid porous polymeric structures have attracted worldwide attention due to their unprecedented opportunities in vast range of applications in diverse fields including chemistry, biological, and medicinal science as gas storage/separation, sensing, and drug delivery systems. Recently, biomedical application has become an interesting and promising issue for development and usage of multi-functional MOFs. Flexible chemical composition and versatile porous structure of MOFs enable the engineering and enhancement of their medical formulation and functionality as practical carriers for whether therapeutic or imaging agents. One important point in this domain is the efficient delivery of drugs in the body using nontoxic and biodegradable carriers. This review brings together the literatures that addressing the biomedical applications of Zinc-based MOFs (i.e. as drug delivery systems or nontoxic agent in matter of therapeutic applications) to present recent achievements in this interesting field.