Recent Advances in Metal-Organic Frameworks as Anticancer Drug Delivery Systems: A Review

Abstract

Background: Metal-organic frameworks (MOFs), as attractive hybrid crystalline porous materials, are increasingly being investigated in biomedical applications owing to their exceptional properties, including high porosity, ultrahigh surface areas, tailorable composition and structure, and tunability and surface functionality. Of interest in this review is the design and development of MOFbased drug delivery systems (DDSs) that have excellent biocompatibility, good stability under physiological conditions, high drug loading capacity, and controlled/targeted drug release. Objective: This review highlights the latest advances in MOFs as anticancer drug delivery systems (DDSs) along with insights on their design, fabrication, and performance under different stimuli that are either internal or external. The synthesis methods of MOFs, along with their advantages and disadvantages, are briefly discussed. The emergence of multifunctional MOF-based theranostic platforms is also discussed. Finally, the future challenges facing the developments of MOFs in the field of drug delivery are discussed. Methods: The review was prepared by carrying out a comprehensive literature survey using relevant work published in various scientific databases. Results: Novel MOFs in biomedical applications, especially in drug delivery, have shown great potentials. MOF-based DDSs can be classified into normal (non-controllable) DDSs, stimuli-responsive DDSs, and theranostic platforms. The normal DDSs are pristine MOFs loaded with MOFs and offer little to no control over the drug delivery. Stimuli-responsive DDSs offer better spatiotemporal control over the drug release by responding to either endogenous (pH, redox, ions, ATP) or exogenous stimuli (light, magnetism, US, pressure, temperature). The theranostic platforms combine stimuli-responsive drug delivery with diagnostic imaging functionality, paving the road for imaging-guided drug delivery. Conclusion: This review presented a summary of the various methods utilized in MOF synthesis along with the advantages and disadvantages of each method. Furthermore, the review highlighted and discussed the latest developments in the field of MOF-based DDSs and theranostic platforms. The review is focused on the characteristics of MOF-based DDSs, the encapsulation of different anticancer drugs as well as their stimuli-responsive release.

pH-Responsive Nanocarriers in Cancer Therapy

“…Metal–organic frameworks (MOFs) are hybrid, i.e., organic and inorganic, porous crystalline materials composed of metal ions and/or clusters connected by organic linkers [ 46 , 47 ]. MOFs have properties that make them quite effective as drug delivery systems, including high surface area and high porosity (which increase drug loading efficiency), open metal sites for physical and chemical interactions, and ease of functionalization.…”

“…MOFs have properties that make them quite effective as drug delivery systems, including high surface area and high porosity (which increase drug loading efficiency), open metal sites for physical and chemical interactions, and ease of functionalization. Drugs can be loaded into MOFs or attached to their surfaces through various inter- and intra-molecular bonds, e.g., hydrogen and covalent bonds, van der Waals forces and electrostatic interconnections [ 46 , 47 , 48 ]. Various methods can be used to synthesize MOFs, which are reviewed in detail in [ 47 ] and summarized in Figure 3 below.…”

“…Drugs can be loaded into MOFs or attached to their surfaces through various inter- and intra-molecular bonds, e.g., hydrogen and covalent bonds, van der Waals forces and electrostatic interconnections [ 46 , 47 , 48 ]. Various methods can be used to synthesize MOFs, which are reviewed in detail in [ 47 ] and summarized in Figure 3 below.…”

Biomedical Applications of Metal−Organic Frameworks for Disease Diagnosis and Drug Delivery: A Review

“…The third type, which combines the two previous classes, is the organic/inorganic hybrid nanocarriers. Lipid−polymer hybrid, ceramic−polymer hybrid, and metal−organic frameworks (MOFs) are among the examples of this kind of nanocarrier [3,28]. This type of nanocarrier combines the advantages of both materials, which strengthens its properties [29].…”

Multimodal imaging and photothermal synergistic immunotherapy of retinoblastoma with tuftsin-loaded carbonized MOF nanoparticles

“…Compared with traditional drug carriers, MOFs have different morphology, composition, size, and chemical properties, enabling a variety of functions and stimulus-responsive controlled drug release (Bowser et al., 2018 ). The enlarged specific surface area and high porosity of MOFs increase their carrying capacity (Karami et al., 2021 ). Moreover, the weak coordination bond ensures the biodegradability of MOFs (Singh et al., 2021 ).…”