Micro- and Nanorobots Meet DNA

DNA, the well-known molecule that carries the genetic information of almost all forms of life, represents a pivotal element in formulating intelligent and versatile micro/nanorobotic systems. DNA-functionalized micro/nanorobots have opened new and exciting opportunities in many research areas due to the synergistic combination of self-propulsion at the micro/nanoscale and the high specificity and programmability of DNA interactions. Here, their designs and applications are critically reviewed, which span from the use of DNA as the fuel to chemotactically power nanorobots toward cancer cells to DNA as the main building block for sophisticated phototactic biorobots, DNA nanodevices to self-monitor microrobots' activity status, DNA and RNA sensing, nucleic acids isolation, gene therapy, and water purification. The perspective on future directions of the field is also shared, envisioning DNA-mediated reconfigurable assemblies of nanorobotic swarms

Nano/Microplastics Capture and Degradation by Autonomous Nano/Microrobots: A Perspective

The growing use of plastic materials has led to the continuous accumulation of wastes in marine environments, which fragment into hazardous micro-and nanoplastics. These plastic particles absorb toxic organic pollutants on their surface, support bacterial biofilms growth, and propagate through the food chain, posing serious risks for human health. Therefore, nano/microplastics pollution has become a global issue, making their definitive elimination compulsory. Self-propelled nano/microrobots have demonstrated efficient removal of nano/microplastics from water, combining enhanced physicochemical properties of nano/microscale materials and active motion. During the last year, the potential of this technology to degrade nano/microplastics has been investigated. Here, the most advanced strategies for nano/microplastics capture and subsequent degradation by autonomous nano/microrobots are critically reviewed. A short introduction to the main propulsion mechanisms and experimental techniques for studying nano/microplastics degradation is also provided. Forthcoming challenges in this research field are discussed proactively. This perspective inspires future nano/microrobotic designs and approaches for water purification from nano/microplastics and other emerging pollutants

High intrinsic activity of the oxygen evolution reaction in low-cost NiO nanowall electrocatalysts

NiO nanowalls grown by low-cost chemical bath deposition and thermal annealing are a high-efficiency and sustainable electrocatalytst for OER

Correction: High intrinsic activity of the oxygen evolution reaction in low-cost NiO nanowall electrocatalysts

Correction for 'High intrinsic activity of the oxygen evolution reaction in low-cost NiO nanowall electrocatalysts' by Salvatore Cosentino et al., Mater. Adv., 2020, DOI: 10.1039/d0ma00467g

Self-Propelled Multifunctional Microrobots Harboring Chiral Supramolecular Selectors for "Enantiorecogniton-on-the-Fly"

Herein, a general procedure for the synthesis of multifunctional MRs, which simultaneously exhibit i) chiral, ii) magnetic, and iii) fluorescent properties in combination with iv) self-propulsion, is reported. Self-propelled Ni@Pt superparamagnetic microrockets have been functionalized with fluorescent CdS quantum dots carrying a chiral host biomolecule as beta-cyclodextrin (beta-CD). The "on-the-fly" chiral recognition potential of MRs has been interrogated by taking advantage of the beta-CD affinity to supramolecularly accommodate different chiral biomolecules (i.e., amino acids). As a proof-of-concept, tryptophan enantiomers have been discriminated with a dual-mode (optical and electrochemical) readout. This approach paves the way to devise intelligent cargo micromachines with "built-in" chiral supramolecular recognition capabilities to elucidate the concept of "enantiorecognition-on-the-fly", which might be facilely customized by tailoring the supramolecular host-guest encapsulation

Shape-Controlled Self-Assembly of Light-Powered Microrobots into Ordered Microchains for Cells Transport and Water Remediation

Nature presents the collective behavior of living organisms aiming to accomplish complex tasks, inspiring the development of cooperative micro/nanorobots. Herein, the spontaneous assembly of hematite-based microrobots with different shapes is presented. Autonomous motile light-driven hematite/Pt microrobots with cubic and walnut-like shapes are prepared by hydrothermal synthesis, followed by the deposition of a Pt layer to design Janus structures. Both microrobots show a fuel-free motion ability under light irradiation. Because of the asymmetric orientation of the magnetic dipole moment in the crystal, cubic hematite/Pt micro-robots can self-assemble into ordered microchains, contrary to the random aggregation observed for walnut-like microrobots. The microchains exhibit different synchronized motions under light irradiation depending on the mutual orientation of the individual microrobots during the assembly, which allows them to accomplish multiple tasks, including capturing, picking up, and transporting microscale objects, such as yeast cells and suspended matter in water extracted from personal care products, as well as degrading polymeric materials. Such light-powered self-assembled microchains demonstrate an innovative cooperative behavior for small-scale multitasking artificial robotic systems, holding great potential toward cargo capture, transport, and delivery, and wastewater remediation

A combined protocol with piroxicam, chemotherapy and whole pelvic irradiation with simultaneous boost volumetric modulated arc radiotherapy for muscle-invasive canine urinary transitional cell carcinoma: first clinical experiences

The aims of this pilot study were to evaluate the feasibility and efficacy of high-dose hypo-fractionated volumetric modulated arc radiotherapy (VMAT) applied to the whole pelvic region radiotherapy (WPRT) with multilevel simultaneous integrated boost (MLSIB) combined with piroxicam and chemotherapy in canine transitional cell carcinoma (TCC) of the lower urinary tract with muscle invasion transitional cell carcinoma (TCC). Twelve dogs were enrolled, according to stage, in two groups: group 1, TCC confined to the urinary tract; group 2, TCC with metastasis. The planning target volume (PTV-tumor) dose was tailored from 36 to 42 Gy in 6 fractions. All dogs were prescribed piroxicam and radiosensitizing carboplatin and six received chemotherapy after radiotherapy. Serial follow-up with computed tomography (CT) and magnetic resonance imaging (MRI) examinations was performed. Disease control and toxicity effects were evaluated according to the Response Evaluation Criteria in Solid Tumor (RECIST) and Veterinary Radiation Therapy Oncology Group (VRTOG) criteria. The treatment was well tolerated, and no high-grade side effects were reported. The median overall survival times for group 1 and group 2 were 1,230 days and 150 days, respectively. A considerable percentage of patients in group 1 (50%) was still alive at the time of writing, and a longer follow-up could enable a more accurate survival analysis. This preliminary analysis showed that VMAT applied to the WPRT with MLSIB is an effective and safe option for dogs suffering from lower urinary TCC although the presence of metastases worsens the prognosis

Severe Corneal Morphological Alterations after Excimer Laser Surface Ablation for a High Astigmatism

We report long-term alterations of anterior corneal stroma after excimer laser surface ablation for a high astigmatism. The patient claimed progressive visual loss in his right eye (RE) during the last 3 years after bilateral laser-assisted subepithelial keratectomy (LASEK) surgery. His examination comprised visual acuity (UDVA and CDVA), slit-lamp examination, corneal topography and tomography, AS-OCT, and confocal microscopy. The UDVA was 0.1 in his RE and 1.0 in the left eye. The CDVA in the RE was 0.8. The slit-lamp examination showed a stromal lesion in the inferior paracentral corneal zone, with multiple vertical tissue bridges and severe thinning. Corneal topography and tomography showed central flattening with inferior steepening and severe alteration in elevation maps. AS-OCT showed void areas in the anterior stroma with thinning of the underlying tissue, and confocal images were not specific. In this case, progressive corneal steepening and thinning that manifest topographically as inferior ectasia occurred in correspondence to the singular stromal alterations after LASEK