by Keyword: silica nanoparticles

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Hortelao AC, Simó C, Guix M, Guallar-Garrido S, Julián E, Vilela D, Rejc L, Ramos-Cabrer P, Cossío U, Gómez-Vallejo V, Patiño T, Llop J, Sánchez S, (2021). Swarming behavior and in vivo monitoring of enzymatic nanomotors within the bladder Science Robotics 6,

Enzyme-powered nanomotors are an exciting technology for biomedical applications due to their ability to navigate within biological environments using endogenous fuels. However, limited studies into their collective behavior and demonstrations of tracking enzyme nanomotors in vivo have hindered progress toward their clinical translation. Here, we report the swarming behavior of urease-powered nanomotors and its tracking using positron emission tomography (PET), both in vitro and in vivo. For that, mesoporous silica nanoparticles containing urease enzymes and gold nanoparticles were used as nanomotors. To image them, nanomotors were radiolabeled with either I on gold nanoparticles or F-labeled prosthetic group to urease. In vitro experiments showed enhanced fluid mixing and collective migration of nanomotors, demonstrating higher capability to swim across complex paths inside microfabricated phantoms, compared with inactive nanomotors. In vivo intravenous administration in mice confirmed their biocompatibility at the administered dose and the suitability of PET to quantitatively track nanomotors in vivo. Furthermore, nanomotors were administered directly into the bladder of mice by intravesical injection. When injected with the fuel, urea, a homogeneous distribution was observed even after the entrance of fresh urine. By contrast, control experiments using nonmotile nanomotors (i.e., without fuel or without urease) resulted in sustained phase separation, indicating that the nanomotors’ self-propulsion promotes convection and mixing in living reservoirs. Active collective dynamics, together with the medical imaging tracking, constitute a key milestone and a step forward in the field of biomedical nanorobotics, paving the way toward their use in theranostic applications. 124 18

Keywords: cell, reversal, silica nanoparticles, size, step, transport, Propelled micromotors

Moya-Andérico L, Vukomanovic M, Cendra MdM, Segura-Feliu M, Gil V, del Río JA, Torrents E, (2021). Utility of Galleria mellonella larvae for evaluating nanoparticle toxicology Chemosphere 266, 129235-129235

© 2020 Elsevier Ltd The use of nanoparticles in consumer products is currently on the rise, so it is important to have reliable methods to predict any associated toxicity effects. Traditional in vitro assays fail to mimic true physiological responses of living organisms against nanoparticles whereas murine in vivo models are costly and ethically controversial. For these reasons, this study aimed to evaluate the efficacy of Galleria mellonella as an alternative, non-rodent in vivo model for examining nanoparticle toxicity. Silver, selenium, and functionalized gold nanoparticles were synthesized, and their toxicity was assessed in G. mellonella larvae. The degree of acute toxicity effects caused by each type of NP was efficiently detected by an array of indicators within the larvae: LD50 calculation, hemocyte proliferation, NP distribution, behavioral changes, and histological alterations. G. mellonella larvae are proposed as a nanotoxicological model that can be used as a bridge between in vitro and in vivo murine assays in order to obtain better predictions of NP toxicity.

Keywords: cellular uptake, cytotoxicity, galleria mellonella, gold nanoparticles, hemocytes, nanoparticles, nanotoxicity, non-rodent in vivo model, non-rodent in vivo model, oxidative stress, selenium-compounds, silica nanoparticles, silver nanoparticles, toxicity, toxicity screening, vitro, Galleria mellonella, Hemocytes, In-vivo model, Nanoparticles, Nanotoxicity, Non-rodent in vivo model, Toxicity screening

Feiner-Gracia, Natalia, Beck, Michaela, Pujals, Sílvia, Tosi, Sébastien, Mandal, Tamoghna, Buske, Christian, Linden, Mika, Albertazzi, Lorenzo, (2017). Super-resolution microscopy unveils dynamic heterogeneities in nanoparticle protein corona Small 13, (41), 1701631

The adsorption of serum proteins, leading to the formation of a biomolecular corona, is a key determinant of the biological identity of nanoparticles in vivo. Therefore, gaining knowledge on the formation, composition, and temporal evolution of the corona is of utmost importance for the development of nanoparticle-based therapies. Here, it is shown that the use of super-resolution optical microscopy enables the imaging of the protein corona on mesoporous silica nanoparticles with single protein sensitivity. Particle-by-particle quantification reveals a significant heterogeneity in protein absorption under native conditions. Moreover, the diversity of the corona evolves over time depending on the surface chemistry and degradability of the particles. This paper investigates the consequences of protein adsorption for specific cell targeting by antibody-functionalized nanoparticles providing a detailed understanding of corona-activity relations. The methodology is widely applicable to a variety of nanostructures and complements the existing ensemble approaches for protein corona study.

Keywords: Heterogeneity, Mesoporous silica nanoparticles, Protein corona, Super-resolution imaging, Targeting

Ma, X., Jannasch, A., Albrecht, U. R., Hahn, K., Miguel-López, A., Schäffer, E., Sánchez, S., (2015). Enzyme-powered hollow mesoporous Janus nanomotors Nano Letters 15, (10), 7043-7050

The development of synthetic nanomotors for technological applications in particular for life science and nanomedicine is a key focus of current basic research. However, it has been challenging to make active nanosystems based on biocompatible materials consuming nontoxic fuels for providing self-propulsion. Here, we fabricate self-propelled Janus nanomotors based on hollow mesoporous silica nanoparticles (HMSNPs), which are powered by biocatalytic reactions of three different enzymes: catalase, urease, and glucose oxidase (GOx). The active motion is characterized by a mean-square displacement (MSD) analysis of optical video recordings and confirmed by dynamic light scattering (DLS) measurements. We found that the apparent diffusion coefficient was enhanced by up to 83%. In addition, using optical tweezers, we directly measured a holding force of 64 ± 16 fN, which was necessary to counteract the effective self-propulsion force generated by a single nanomotor. The successful demonstration of biocompatible enzyme-powered active nanomotors using biologically benign fuels has a great potential for future biomedical applications.

Keywords: Enzyme, Hollow mesoporous silica nanoparticles, Hybrid motors, Janus particles, Nanomotors, Optical tweezers