Microrobotic swarms for selective embolization

Abstract

Inspired by the collective intelligence in natural swarms, microrobotic agents have been controlled to form artificial swarms for targeted drug delivery, enhanced imaging, and hyperthermia. Different from these well-investigated tasks, this work aims to develop microrobotic swarms for embolization, which is a clinical technique used to block blood vessels for treating tumors, fistulas, and arteriovenous malformations. Magnetic particle swarms were formed for selective embolization to address the low selectivity of the present embolization technique that is prone to cause complications such as stroke and blindness. We established an analytical model that describes the relationships between fluid viscosity, flow rate, branching angle, magnetic field strength, and swarm integrity, based on which an actuation strategy was developed to maintain the swarm integrity inside a targeted region under fluidic flow conditions. Experiments in microfluidic channels, ex vivo tissues, and in vivo porcine kidneys validated the efficacy of the proposed strategy for selective embolization.

Applications of Nano/Micromotors for Treatment and Diagnosis in Biological Lumens

“…Nano/micromotors have been explored to achieve selective embolization. Law et al [ 85 ] designed a superparamagnetic particle coated with thrombin ( Figure 3 b). They deduced that the motor would agglutinate in a certain magnetic field.…”

“…Reprinted with permission from ref. [ 78 , 85 ]. ( d ) The ejection of O 2 bubbles and the cavitation effect produced by the ultrasonication of O 2 could be the power source of the Janus rod (JR)-shaped motors.…”

Programming structural and magnetic anisotropy for tailored interaction and control of soft microrobots

“…For this purpose, soft microrobots made of biocompatible materials have attracted special interest due to their deformability and ability 9 to mimic human cells such as red blood cells and leukocytes that navigate the cardiovascular system 10 . Such synthetic microrobots should be designed to readily flow within the bloodstream and moreover be amenable to external control via wireless transmittable stimuli, such as magnetic fields [11][12][13][14] , light 15,16 , ultrasound [17][18][19] , chemical reactions, or temperature 20,21 . In response to external cues, microrobots may change their shape to release a drug, capture a biological sample, or execute a certain motion or propulsion scheme 22 .…”

Gravity-resisting colloidal collectives

“…While the formation of static structures is through energy minimization, dynamic collectives actively consume energy to gain structural complexity and function diversity (1)(2)(3)(4). Dynamic colloidal self-assembly is an essential means of creating functional materials and systems to enable applications in materials engineering such as the formation of intelligent matters (5), in chemical engineering such as catalysis (6,7), in microfactories such as contactless material handling (8)(9)(10) and the construction of photonic crystals (11,12), and in health care such as targeted delivery (13)(14)(15)(16) and therapeutics (17).…”