Multiscale Magnetic Hydrogel Robot with a Core–Shell Structure for Active Targeted Delivery

Abstract

Tremendous progress in applying small-scale magnetic robots for targeted drug delivery has sparked a growing interest among researchers. However, significant effort is needed to design and fabricate robots to meet the needs of clinical treatments, such as biocompatibility, biodegradation, and synergistic therapy. Here, we propose a multiscale magnetic hydrogel robot (MMHR) with a core–shell structure in which superparamagnetic nanoparticles and curcumin-loaded chitosan microparticles (CCMs) are encapsulated inside the core, while doxorubicin-loaded chitosan microparticles (DCMs) are embedded inside the shell. The core and shell of the MMHR are composed of pH-sensitive calcium alginate hydrogels that can alleviate the sudden release of drugs from CCMs and DCMs in gastric fluid. MMHRs can be precisely actuated to the target region through magnetic driving systems for further drug delivery. The experimental results demonstrate that the MMHR possesses superior obstacle-crossing ability and can successfully locomote on the surface of the intestine. Additionally, the co-delivery of doxorubicin and curcumin is realized through the different fabrication methods of CCMs and DCMs and shows excellent synergistic therapeutic effects against colon cancer cells. The powerful propulsion, good biocompatibility, and remarkable synergistic efficacy of the MMHR offer a promising route for active drug delivery through the gastrointestinal tract.

Biodegradable Magnetic Hydrogel Robot with Multimodal Locomotion for Targeted Cargo Delivery

“…The simple fabrication method of the BMHR makes it easy to combine it with drug-loaded microparticles that have been proven to be effective in drug-sustained release. As illustrated in Figure a, chitosan microparticles were prepared using the emulsification cross-linking method with doxorubicin (DOX) loaded in the particles, , and the drug-loaded BMHR was prepared by evenly mixing the chitosan microparticles into a gelatin solution. The scanning electron microscopy (SEM) image in Figure b indicated that the chitosan particles possess a spherical shape.…”

A Polysaccharide-Based pH-Sensitive Hybrid Hydrogel as a Sustained Release Matrix for Antimicrobial Drugs

“…However, the aqueous solubility of polysaccharides and the presence of functional groups are beneficial to make either gel precursors or interpenetrating polymeric networks in the aqueous medium. ,,,− Although polysaccharides (such as starch, chitosan, pullulan, hyaluronic acid, glycogen, cyclodextrin, etc.) have been explored to design stimulus-responsive hydrogels for drug-delivery applications, ,,,,,,,− polysaccharide-based hydrogels are susceptible to rapid erosion owing to their feeble mechanical strength and are not very efficient in controlled drug release applications. , Moreover, the hydrogel matrix must pass the physiological challenges (e.g., gastrointestinal transit time, pH, mucus, fluid volume, enzyme, or microbiome) in the human gastrointestinal tract (GI) in oral drug delivery . Considering all the above issues, designing a polysaccharide-based smart hydrogel is needed.…”

“…Mucoadhesive hydrogels have been utilized to contact a drug release system on a specific part for targeted delivery and optimum drug release because of the affinity and span of contact . Polysaccharides have immense importance in hydrogel preparation for drug delivery applications as they are renewable, biodegradable, and cytocompatible. − ,,− However, gel strength and porosity are the controlling factors for sustained drug release application. Low-molecular-weight polysaccharides (e.g., dextrin) are not suitable because they are soluble in physiological media .…”

Fabrication of Red Blood Cell-Mimicking Janus Microparticles with Enhanced Upconversion Luminescence and Drug Delivery Performance Using Double-Needle Electrospray

“…15−17 Fe 3 O 4 magnetic nanoparticles (MNPs) and luminescent materials are often employed for targeting and tracing to improve drug delivery efficiency. 17,18 As the most commonly used super-paramagnetic nanoparticles, Fe 3 O 4 MNPs exhibit low toxicity and can be used in drug targeting, medical diagnosis, and optical imaging, and the Food and Drug Administration of the United States has also approved them for clinical use. 19 In terms of luminescent materials, traditional luminescent agents are usually harmful to cells and prone to quenching.…”

“…Apart from the size and shape, the function of particles as carriers is also critical for enhancing the efficiency of drug delivery. − Fe 3 O 4 magnetic nanoparticles (MNPs) and luminescent materials are often employed for targeting and tracing to improve drug delivery efficiency. , As the most commonly used super-paramagnetic nanoparticles, Fe 3 O 4 MNPs exhibit low toxicity and can be used in drug targeting, medical diagnosis, and optical imaging, and the Food and Drug Administration of the United States has also approved them for clinical use . In terms of luminescent materials, traditional luminescent agents are usually harmful to cells and prone to quenching. , Rare earth ion upconversion (UC) luminescent materials excited by near-infrared (NIR) light can avoid these issues, minimize auto-luminescence from biological tissues, and penetrate tissues to a greater extent with acceptable biocompatibility. , Moreover, the direct interactions between magnetic and luminescent materials remarkably reduce the performance of each component, especially the luminescent intensity, which is not conducive to tracing .…”