Abstract:While recent wireless micromachines have shown increasing potential for medical use, their potential safety risks concerning biocompatibility need to be mitigated. They are typically constructed from materials that are not intrinsically compatible with physiological environments. Here, we propose a personalized approach by using patient blood-derivable biomaterials as the main construction fabric of wireless medical micromachines to alleviate safety risks from biocompatibility. We demonstrate 3D printed multir… Show more
“…Besides effective propulsion and precise control, biocompatibility of the microrobots represents another important translation aspect of this technology. Encapsulating the microrobots inside the patient’s own cells ( 66 ) and the use of biocompatible materials ( 67 , 68 ) would decrease biotoxicity, thus enabling long-term in vivo studies toward medical applications. In addition, the corona effect should be considered as dynamic process that can trigger a host response, leading to encapsulation of the implanted material ( 69 ).…”
Mobile microrobots hold remarkable potential to revolutionize health care by enabling unprecedented active medical interventions and theranostics, such as active cargo delivery and microsurgical manipulations in hard-to-reach body sites. High-resolution imaging and control of cell-sized microrobots in the in vivo vascular system remains an unsolved challenge toward their clinical use. To overcome this limitation, we propose noninvasive real-time detection and tracking of circulating microrobots using optoacoustic imaging. We devised cell-sized nickel-based spherical Janus magnetic microrobots whose near-infrared optoacoustic signature is enhanced via gold conjugation. The 5-, 10-, and 20-μm-diameter microrobots are detected volumetrically both in bloodless ex vivo tissues and under real-life conditions with a strongly light-absorbing blood background. We further demonstrate real-time three-dimensional tracking and magnetic manipulation of the microrobots circulating in murine cerebral vasculature, thus paving the way toward effective and safe operation of cell-sized microrobots in challenging and clinically relevant intravascular environments.
“…Besides effective propulsion and precise control, biocompatibility of the microrobots represents another important translation aspect of this technology. Encapsulating the microrobots inside the patient’s own cells ( 66 ) and the use of biocompatible materials ( 67 , 68 ) would decrease biotoxicity, thus enabling long-term in vivo studies toward medical applications. In addition, the corona effect should be considered as dynamic process that can trigger a host response, leading to encapsulation of the implanted material ( 69 ).…”
Mobile microrobots hold remarkable potential to revolutionize health care by enabling unprecedented active medical interventions and theranostics, such as active cargo delivery and microsurgical manipulations in hard-to-reach body sites. High-resolution imaging and control of cell-sized microrobots in the in vivo vascular system remains an unsolved challenge toward their clinical use. To overcome this limitation, we propose noninvasive real-time detection and tracking of circulating microrobots using optoacoustic imaging. We devised cell-sized nickel-based spherical Janus magnetic microrobots whose near-infrared optoacoustic signature is enhanced via gold conjugation. The 5-, 10-, and 20-μm-diameter microrobots are detected volumetrically both in bloodless ex vivo tissues and under real-life conditions with a strongly light-absorbing blood background. We further demonstrate real-time three-dimensional tracking and magnetic manipulation of the microrobots circulating in murine cerebral vasculature, thus paving the way toward effective and safe operation of cell-sized microrobots in challenging and clinically relevant intravascular environments.
“…The size and lack of flexibility may damage the walls of the vessels and limit the size of the vessels in applications. Figure 3 Some of the most recent microbots designed for the vasculature system: ( a ) ciliary microbot [ 35 ]; ( b ) soft attractor wall microbot [ 36 ]; ( c ) self-folding microbot [ 38 ]; ( d ) sperm-shaped microbot [ 40 ]; ( e ) snake-shaped microbot [ 41 ]; ( f ) scallop-shaped microrobot [ 42 ]; ( g ) microrocket robot [ 43 ]; ( h ) surface microrollers [ 45 ]; ( i ) helical microbots [ 46 ]. All images have been reproduced with permission from the corresponding publishers, therefore further requests for permission related to the material excerpted should be directed to them.…”
Section: Microbots Designed For the Circulatory Systemmentioning
confidence: 99%
“…Concerning biocompatibility, safety risks could be mitigated by constructing the microbots from materials intrinsically compatible with physiological environments. Ceylan et al [ 46 ] proposed a personalized approach by using patient blood–derivable biomaterials as the main construction fabric of wireless medical micromachines to alleviate safety risks from biocompatibility. They demonstrated that it is possible to 3D print multiresponsive microswimmers and microrollers made from magnetic nanocomposites of blood plasma, serum albumin protein, and platelet lysate.…”
Section: Microbots Designed For the Circulatory Systemmentioning
Microbots have been considered powerful tools in minimally invasive medicine. In the last few years, the topic has been highly studied by researchers across the globe to further develop the capabilities of microbots in medicine. One of many applications of these devices is performing surgical procedures inside the human circulatory system. It is expected that these microdevices traveling along the microvascular system can remove clots, deliver drugs, or even look for specific cells or regions to diagnose and treat. Although many studies have been published about this subject, the experimental influence of microbot morphology in hemodynamics of specific sites of the human circulatory system is yet to be explored. There are numerical studies already considering some of human physiological conditions, however, experimental validation is vital and demands further investigations. The roles of specific hemodynamic variables, the non-Newtonian behavior of blood and its particulate nature at small scales, the flow disturbances caused by the heart cycle, and the anatomy of certain arteries (i.e., bifurcations and tortuosity of vessels of some regions) in the determination of the dynamic performance of microbots are of paramount importance. This paper presents a critical analysis of the state-of-the-art literature related to pulsatile blood flow around microbots.
“…Indeed, two-photon polymerization, which is a VP-based 3D printing method, has been used to fabricate microscale magnetic robots with complex 3D geometries. [26][27][28][29] However, these magnetic robots have rigid bodies and low magnetic-particle-loading ratios; therefore, they cannot actively morph their shapes to achieve sophisticated mechanical functionalities. The feasibility of using VP-based 3D printing methods to create MSMRs with uniform and high magnetic-particle loading in addition to realizing true 3D initial geometries and 3D shaping morphing capabilities is yet to be investigated.…”
3D printing via vat photopolymerization (VP) is a highly promising approach for fabricating magnetic soft millirobots (MSMRs) with accurate miniature 3D structures; however, magnetic filler materials added to resin either strongly interfere with the photon energy source or sediment too fast, resulting in the nonuniformity of the filler distribution or failed prints, which limits the application of VP. To this end, a circulating vat photopolymerization (CVP) platform that can print MSMRs with high uniformity, high particle loading, and strong magnetic response is presented. After extensive characterization of materials and 3D printed parts, it is found that SrFe12O19 is an ideal magnetic filler for CVP and can be printed with 30% particle loading and high uniformity. By using CVP, various tethered and untethered MSMRs are 3D printed monolithically and demonstrate the capability of reversible 3D‐to‐3D transformation and liquid droplet manipulation in 3D, an important task for in vitro diagnostics that are not shown with conventional MSMRs. A fully automated liquid droplet handling platform that manipulates droplets with MSMR is presented for detecting carbapenem antibiotic resistance in hazardous biosamples as a proof of concept, and the results agree with the benchmark.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
