Encapsulation of Gemcitabine on Porphyrin Aluminum Metal-Organic Framework by Mechano-Chemistry, Delayed Drug Release and Cytotoxicity to Pancreatic Cancer PANC-1 Cells

Gemcitabine is a widely used antimetabolite drug of pyrimidine structure, which can exist as a free-base molecular form (Gem). The encapsulated forms of medicinal drugs are of interest for delayed and local drug release. We utilized, for the first time, a novel approach of mechano-chemistry by liquid-assisted grinding (LAG) to encapsulate Gem on a "matrix" of porphyrin aluminum metal-organic framework Al-MOF-TCPPH2 (compound 2). The chemical bonding of Gem to compound 2 was studied by ATR-FTIR spectroscopy and powder XRD. The interaction involves the C=O group of Gem molecules, which indicates the formation of the encapsulation complex in the obtained composite. Further, the delayed release of Gem from the composite was studied to phosphate buffered saline (PBS) at 37 °C using an automated drug dissolution apparatus equipped with an autosampler. The concentration of the released drug was determined by HPLC-UV analysis. The composite shows delayed release of Gem due to the bonded form and constant concentration thereafter, while pure Gem shows quick dissolution in less than 45 min. Delayed release of Gem drug from the composite follows the kinetic pseudo-first-order rate law. Further, for the first time, the mechanism of delayed release of Gem was assessed by the variable stirring speed of drug release media, and kinetic rate constant k was found to decrease when stirring speed is decreased (diffusion control). Finally, the prolonged time scale of toxicity of Gem to pancreatic cancer PANC-1 cells was studied by continuous measurements of proliferation (growth) for 6 days, using the xCELLigence real-time cell analyzer (RTCA), for the composite vs. pure drug, and their differences indicate delayed drug release. Aluminum metal-organic frameworks are new and promising materials for the encapsulation of gemcitabine and related small-molecule antimetabolites for controlled delayed drug release and potential use in drug-eluting implants.

UiO-66-NH2: a recyclable and efficient sorbent for dispersive solid-phase extraction of fluorinated aromatic carboxylic acids from aqueous matrices

The present study describes the trace analysis of 23 fluorinated aromatic carboxylic acids based on the dispersive solid-phase extraction (dSPE) technique using UiO-66-NH₂ MOF as efficient, recyclable sorbent, and GC-MS negative ionization mass spectrometry (NICI MS) as determination technique. All 23 fluorobenzoic acids (FBAs) were enriched, separated, and eluted in a shorter retention time; the derivatization was done by pentafluorobenzyl bromide (1% in acetone), in which the use of inorganic base K₂CO₃ was improved by triethylamine to increase the lifespan of the GC column. The performance of UiO-66-NH₂ was evaluated by dSPE in Milli-Q water, artificial seawater, and tap water samples, and the impact of various parameters on the extraction efficiency was investigated by GC-NICI MS. The method was found to be precise, reproducible, and applicable to the seawater samples. In the linearity range, the regression value was found to be >0.98; LOD and LOQ were found to be in the range of 0.33-1.17 ng/mL and 1.23-3.33 ng/mL, respectively; and the value of the extraction efficiency was found to range between 98.45 and 104.39% for Milli-Q water samples, 69.13-105.48% for salt-rich seawater samples, and 92.56-103.50% for tap water samples with a maximum RSD value of 6.87% that confirms the applicability of the method to different water matrices.

Lanthanide-based MOFs: synthesis approaches and applications in cancer diagnosis and therapy

Metal-organic frameworks (MOFs) have attracted considerable attention as emerging nanomaterials. Based on their tunable size, high porosity, and large specific surface area, MOFs have a wide range of applications in the fields of chemistry, energy, and biomedicine. However, the MOF materials obtained from lanthanides with a unique electronic configuration as inorganic building units have unique properties such as optics, magnetism, and radioactivity. In this study, various synthetic methods for preparing MOF materials using lanthanides as inorganic building units are described. Combined with the characteristics of lanthanides, their application prospects of lanthanide-based MOFs in tumor diagnosis and treatment are emphasized. The authors hope to provide methodological reference for the construction of MOF materials of rare-earth elements, and to provide ideas and inspiration for their practical applications in the field of biomedicine.

Rare-earth metal–organic frameworks: from structure to applications

In the past 30 years, rare-earth metal–organic frameworks (MOFs) have been gaining attention owing to their diverse chemical structures, and tunable properties.

Metal-Organic Framework (MOF)-based Nanomaterials for Biomedical Applications

BACKGROUND

Metal-organic frameworks (MOFs), as a new class of porous organic-inorganic crystalline hybrid materials that governed by the self-assembled of metal atoms and organic struts have attracted tremendous attention because of their special properties. Recently, some more documents have reported different types of nanoscale metal-organic frameworks (NMOFs) as biodegradable and physiological pH-responsive systems for photothermal therapy and radiation therapy in the body.

DISCUSSION

In this review paper aims at describing the benefits of using MOF nanoparticles in the field of biomedicine, and putting into perspective their properties in the context of the ones of other NPs. The first section briefly reviews the biomaterial scaffolds of MOFs. The second section presents the main types of stimuli-responsive mechanisms and strategies from two categories: intrinsic (pH, redox state) and extrinsic (temperature, light irradiation and magnetic field) ones. The combinations of photothermal therapy and radiation therapy have been concluded in detail. Finally, clinical applications of MOFs, future challenges and perspectives are also mentioned.

CONCLUSION

This review outlines the most recent advances MOFs design and biomedical applications, from different synthesis to their use as smart drug delivery systems, bioimaging technology or a combination of both.

Solid-phase extraction of phenoxyacetic acid herbicides in complex samples with a zirconium(IV)-based metal-organic framework

A zirconium(IV)-based metal-organic framework material (MOF-808) has been synthesized in a simple way and used for the extraction of phenoxyacetic acids in complex samples. The material has good thermal and chemical stability, large specific surface area (905.36 m²/g), and high pore size (22.18 Å). Besides, it contains a large amount of Zr-O groups, easy-to-form Zr-O-H bond with carboxyl groups of phenoxyacetic acids, and possesses biphenyl skeleton structure, easy to interact with compounds through π-π and hydrophobic interactions. These characteristics make the material very suitable for the extraction of certain compounds with a high extraction efficiency and excellent selectivity. The extraction conditions were optimized, and then an analytical method was successfully established and applied for analysis of actual samples. The solid-phase extraction method based on prepared material had a wide linear range of 0.2-250 μg/L and a low detection limit of 0.1-0.5 μg/L for four phenoxyacetic acid compounds including 2,4-dichlorophenoxyacetic acid, 2-(2,4-dichlorophenoxy) propionic acid, 4-chlorophenoxyacetic acid, and dicamba. The relative standard deviations of intra- and interday precision were 1.8-3.8 and 4.3-6.9%, and the recoveries after spiking were between 77.1 and 109.3%. The results showed that the material is a desired substituent for the extraction of compounds with benzene ring structure containing carboxyl groups.

Luminescent Lanthanide MOFs: A Unique Platform for Chemical Sensing

In recent years, lanthanide metal-organic frameworks (LnMOFs) have developed to be an interesting subclass of MOFs. The combination of the characteristic luminescent properties of Ln ions with the intriguing topological structures of MOFs opens up promising possibilities for the design of LnMOF-based chemical sensors. In this review, we present the most recent developments of LnMOFs as chemical sensors by briefly introducing the general luminescence features of LnMOFs, followed by a comprehensive investigation of the applications of LnMOF sensors for cations, anions, small molecules, nitroaromatic explosives, gases, vapors, pH, and temperature, as well as biomolecules.

An Adeninate-Based Metal–Organic Framework for Antitumour Drug Delivery and Anti-Osteogenic Sarcoma Activity Evolution

Targeted anticancer drug delivery systems (DDSs) have been considered as one of the most important approaches for reducing the side effects and enhancing the therapy effect in cancer treatment. This work presents a targeted anticancer DDS on the basis of a newly synthesised adeninate-based metal–organic framework (MOF) [Zn2(ad)2(AMDB)(H2O)](DMF)3 (1) with biomolecular adenine (HAd), zinc(ii) ions, and 4,4′-(aminomethylene)dibenzoic acid (H2AMDB) as the molecular building blocks. The structural analysis via X-ray diffraction technology shows MOF 1 is a channel-type three-dimensional network composed of rod-like Zn–Ad chains. Due to its large inner free spaces and uncoordinated N donor sites functionalised pore surroundings, the antitumour molecule 5-fluorouracil (5-Fu) could be loaded into the pores of 1a (activated 1) though an adsorption process, which shows a moderate high storage capacity of 32 wt-%. At the same time, the pH-dependent delivery of 5-Fu could be achieved in phosphate-buffered saline (PBS) solution. With a lower pH value, the drug release will be enhanced. Furthermore, the invitro antitumour activity of the drug/1a composite has been probed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on two human osteogenic sarcoma cells (MG63 and U2OS).

Determination of chlorophenoxy acid herbicides by using a zirconium-based metal–organic framework as special sorbent for dispersive micro-solid-phase extraction and high-performance liquid chromatography

This study reports a Zr-based MOF with 2-amino-benzenedicarboxylic acid ligand as an adsorbent for chlorophenoxy acid herbicides from biosamples.