Treatment of persistent biofilm infections has turned out to be a formidable challenge even with broad-spectrum antibiotic therapies. In this direction, intelligent micromachines may serve as active mechanical means to dislodge such deleterious bacterial communities. Herein, we have designed biocompatible micromotors from tea buds, namely, T-Budbots, which shows the capacity to be magnetically driven on a biofilm matrix and remove or fragment biofilms with precision, as a part of the proposed non-invasive "Kill-n-Clean" strategy. In a way, we present a bactericidal robotic platform decorated with magnetite nanoparticles aimed at clearing in vitro biofilms present on the surfaces. We have also shown that the smart porous T-Budbots can integrate antibiotic ciprofloxacin due to electrostatic interaction on their surface to increase their antibacterial efficacy against dreadful pathogenic bacterial communities of Pseudomonas aeruginosa and Staphylococcus aureus. It is noteworthy that the release of this drug can be controlled by tuning the surrounding pH of the T-Budbots. For example, while the acidic environment of the biofilm facilitates the release of antibiotics from the porous T-Budbots, the drug release was rather minimal at higher pH. The work represents a first step in the involvement of a plant-based microbot exhibiting magneto-robotic therapeutic properties, providing a non-invasive and safe approach to dismantle harmful biofilm infections.

Multifunctional chemically powered micromotors were fabricated from the airborne contaminant carbon soot (CS) for environmental remediation following two approaches: first, by physical deposition of catalytic platinum (Pt) and magnetic nickel (Ni) nanoscale films of ∼110 nm and ∼100 nm, respectively, on CS (CARBOts) and second, by the chemical deposition of magneto-catalytic iron nanoparticles (FeNPs) of ∼30 nm or less in size on the CS surface (iCARBOts). The chemical synthesis of magneto-catalytic iron nanoparticle (FeNPs)-based iCARBOts provides an economical alternative to the synthesis of CARBOts by a physical method. The hydrophobic soot contained agglomerates of high-density carbon nanospheres of ∼40 nm or less in size, generated from the incomplete combustion of a hydrocarbon source. The catalytic component (Pt nanofilm or FeNPs) on the nanostructures on the CS surface allowed the rapid catalytic decomposition of aqueous peroxide fuel (H2O2) to generate chemical propulsion. The issuance of O2 microbubbles from the motor surface imparted the required thrust for active bubble propulsion. Integration of a magnetic component (Ni nanofilm or FeNPs) facilitated remote magnetic control for micromotor navigation. These magneto-catalytic micromotors demonstrated the efficient catalytic degradation of methylene blue (MB) dye in the presence of 10% (v/v) H2O2 fuel under ambient conditions. The CARBOts completely decolorized the nonbiodegradable MB dye pollutant within 40 min of treatment. The magnetic sensitivity of motors facilitated the ease of retrieval and reusability after the execution of the remediation tasks, thereby increasing the feasibility of the water detoxification process. In addition, with the help of remote magnetic guidance, micromotors were employed for the removal of freely floating and surfactant-stabilized oil droplets in seawater without any further surface modification. The intrinsic superoleophilic nature of the micromotors owing to the presence of the nanostructured soot surface facilitated an enhanced oil–motor interaction, which led to efficient on-the-fly capturing of oil droplets with remote magnetic guidance.

Hemorrhage is the leading cause of trauma-related deaths, in hospital and pre-hospital settings. Hemostasis is a complex mechanism that involves a cascade of clotting factors and proteins that result in the formation of a strong clot. In certain surgical and emergency situations, hemostatic agents are needed to achieve faster blood coagulation to prevent the patient from experiencing a severe hemorrhagic shock. Therefore, it is critical to consider appropriate materials and designs for hemostatic agents. Many materials have been fabricated as hemostatic agents, including synthetic and naturally derived polymers. However, compared to synthetic polymers, natural polymers or biopolymers, which include polysaccharides and polypeptides, have greater biocompatibility, biodegradability, and processibility. Thus, in this review, we focus on biopolymer-based hemostatic agents of different forms, such as powder, particles, sponges, and hydrogels. Finally, we discuss biopolymer-based hemostats currently in clinical trials and offer insight into next-generation hemostats for clinical translation.

We explore the salient features of electroosmotic flow inside patterned and deformable microchannels. A computational fluid dynamic simulator is developed to solve the coupled Poisson's equation for electrolyte, Laplace equation for external electric field, and continuity and momentum equations for fluid flow, with appropriate boundary conditions. The simulations reveal existence of some exceptional flow profiles with the variations in normalized Debye length, dimensions, and locations of heterogeneities, strength of external field, and deformability of walls. The surface heterogeneities are found to facilitate the variation in ζ-potential, which in turn locally modulate the flow rate to cause intermixing of layers. The extent of mixing due to the deformability and heterogeneity of the walls have been analyzed to identify the conditions for augmented micromixing in laminar electroosmotic flows. The variations of current densities along the walls with surface patterns have been explored for the probable application in differentiating the ζ-potentials of biosurfaces.

Microphysiological systems (MPSs), also known as organ-on-a-chip models, aim to recapitulate the functional components of human tissues or organs in vitro. Over the last decade, with the advances in biomaterials,...