Biodegradable Metal–Organic Framework‐Based Microrobots (MOFBOTs)

Abstract

Microrobots and metal-organic frameworks (MOFs) have been identified as promising carriers for drug delivery applications. While clinical applications of microrobots are limited by their low drug loading efficiencies and the poor degradability of the materials used for their fabrication, MOFs lack motility and targeted drug delivery capabilities. The combination of these two fields marks the beginning of a new era; MOF-based small-scale robots (MOFBOTs) for biomedical applications. Yet, biodegradability is a major hurdle in the field of micro-and nanoswimmers including small-scale robots. Here, a highly integrated MOFBOT that is able to realize magnetic locomotion, drug delivery, and selective degradation in cell cultures is reported for the first time. The MOF used in the investigations does not only allow a superior loading of chemotherapeutic drugs and their controlled release via a pH-responsive degradation but it also enables the controlled locomotion of enzymatically biodegradable gelatin-based helical microrobots under magnetic fields. The degradation of the integrated MOFBOT is observed after two weeks, when all its components fully degrade. Additionally, drug delivery studies performed in cancer cell cultures show reduced viability upon delivery of Doxorubicin within short time frames. This MOFBOT system opens new avenues for highly integrated fully biodegradable small-scale robots.

Enzyme-Powered Porous Micromotors Built from a Hierarchical Micro- and Mesoporous UiO-Type Metal–Organic Framework

“…MOFs exhibit very high surface areas, tunable pore sizes and shapes, and adjustable pore-surface functionality, suggesting their potential for myriad applications, including gas-storage, separation, catalysis, contaminant removal, and drug delivery. 18,19 In fact, researchers have used MOFs to build stable and adaptable chassis for micro-and nanomotors, 20,21 in which motion is based on Marangoni effects, [22][23][24][25] magneticallydriven corkscrew locomotion 26,27 or bubble propulsion [28][29][30][31][32][33][34] . For the latter, studies are si far mostly limited to metallic catalytic materials (e.g.…”

Magnetic-Propelled Janus Yeast Cell Robots Functionalized with Metal-Organic Frameworks for Mycotoxin Decontamination

“…Coating yeast cells with MNPs and MOF yields biogenic magnetic catalysts with self-propulsion and enhanced capability in environmental remediation, such as mycotoxin removal in drinking water sources, and can be readily expanded to other types of cells and artificial wrappings in designing versatile cell robots for broader applications, such as drug delivery, biosensing, and bioconversion [ 45 , 51 , 52 ]. Future efforts may lead to simplify fabrication process with one-step method to synthesize magnetic ZIF composites [ 53 ] and develop biocompatible coatings, such as ZIF-8 [ 54 ]. Such magnetic-powered microsystem may also face constrains as large and complex requirements may be required in practical applications, causing money-consuming and inconvenient process.…”

Metal–Organic Frameworks in Motion

“…Biodegradable MOFBOTs for targeted drug delivery have been recently developed by the same group. 117 The researchers implemented organomineralised magnetic Fe@ZIF-8 composite particles, which were produced in a simple one-pot synthesis. The Fe@ZIF-8 crystals were successfully integrated on the surface of soft gelatine-based helical microchassis.…”

“…Their implementation in biomedical applications has so far shown promising results in the field of targeted drug delivery. 116,117 The materials' biocompatibility for every system is assessed with (+++) for biocompatible and biodegradable components, (++) for biocompatible but non-degradable components, (+) for biocompatible in short-term but potentially long-term toxicity due to components degradation (i.e. : Co, Ni, etc.).…”