Metal–Organic Frameworks (MOF)-Assisted Sonodynamic Therapy in Anticancer Applications

Abstract

Sonodynamic therapy (SDT) has emerged as a promising therapeutic modality for anticancer treatments and is becoming a cutting-edge interdisciplinary research field. This review starts with the latest developments of SDT and provides a brief comprehensive discussion on ultrasonic cavitation, sonodynamic effect, and sonosensitizers in order to popularize the basic principles and probable mechanisms of SDT. Then the recent progress of MOF-based sonosensitizers is overviewed, and the preparation methods and properties (e.g., morphology, structure, and size) of products are presented in a fundamental perspective. More importantly, many deep observations and understanding toward MOF-assisted SDT strategies were described in anticancer applications, aiming to highlight the advantages and improvements of MOF-augmented SDT and synergistic therapies. Last but not least, the review also pointed out the probable challenges and technological potential of MOF-assisted SDT for the future advance. In all, the discussions and summaries of MOF-based sonosensitizers and SDT strategies will promote the fast development of anticancer nanodrugs and biotechnologies.

Understanding the role of metal–organic frameworks in cancer treatment

“…95,96 In a typical SDT process, nanolevel transient pores are formed on the cell membrane, which can improve the permeability of tissues. 97 Importantly, US exhibits satisfying tissue penetrability and biological safety, which supports the potential application of SDT. Actually, ultrasound irradiation has been employed as an ideal tool for clinical cancer imaging treatment.…”

“…In order to avoid the rapid degradation of organic sonosensitizers, encapsulating these molecules into the pore of MOFs is a simple and feasible method. 97 Huang et al developed a Cu-MOF with Cu ion and azobenzene 4,4-dicarboxylic acid ligand and encapsulated 2,2-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH) into the Cu-MOF (Fig. S7a).…”

“…Actually, ultrasound irradiation has been employed as an ideal tool for clinical cancer imaging treatment. 97 The design and selection of sonosensitizers are mostly focused on semiconductors with rational band gaps. 40 However, the clinical applications of SDT suffer from either the fast elimination of organic sonosensitizers in in vivo environment or the non-degradability of inorganic ones.…”

Improvement of the effectiveness of sonodynamic therapy: by optimizing components and combination with other treatments

“…Unfortunately, the inherent shortcomings of photosensitizers, such as long-term skin sensitivity, low bioavailability, and poor stability, cannot be avoided, which limits the use of organic sonosensitizers in practical practice. [81][82][83][84][85] Inorganic sonosensitizers include titanium dioxide (TiO 2 ), zinc oxide (ZnO 2 ), black phosphorus (BP), Bi 2 MoO 6 , MnWO x , and so on. In many previous studies, inorganic sonosensitizers have been found to have superior physical and chemical properties and high stability and can provide more nucleation sites for cavitation bubbles by ultrasonic stimulation, resulting in continuous ROS generation.…”

Emerging porous solids and sonochemistry

“…In addition, we review sonocatalysis and sonodynamic therapy (SDT) using emerging porous solids as sonosensitizers (Scheme 1). While a limited number of reviews that discuss MOF sonosynthesis 8 and SDT using MOFs from biological and therapeutic perspectives have appeared, 20,21 no comprehensive review that covers sonosynthesis, sonocatalysis, and SDT from the porousmaterial perspective appears to exist. In particular, this is the first review that explores the use of sonochemistry in COF and POP applications, as previous reviews only focused on MOFs.…”