Publications

This study investigates the synthesis and optimization of nanobots (NBs) loaded with pDNA using the layer-by-layer (LBL) method and explores the impact of their collective motion on the transfection efficiency. NBs consist of biocompatible and biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and are powered by the urease enzyme, enabling autonomous movement and collective swarming behavior. In vitro experiments were conducted to validate the delivery efficiency of fluorescently labeled NBs, using two-dimensional (2D) and three-dimensional (3D) cell models: murine urothelial carcinoma cell line (MB49) and spheroids from human urothelial bladder cancer cells (RT4). Swarms of pDNA-loaded NBs showed enhancements of 2.2- to 2.6-fold in delivery efficiency and 6.8- to 8.1-fold in material delivered compared to inhibited particles (inhibited enzyme) and the absence of fuel in a 2D cell culture. Additionally, efficient intracellular delivery of pDNA was demonstrated in both cell models by quantifying and visualizing the expression of eGFP. Swarms of NBs exhibited a >5-fold enhancement in transfection efficiency compared to the absence of fuel in a 2D culture, even surpassing the Lipofectamine 3000 commercial transfection agent (cationic lipid-mediated transfection). Swarms also demonstrated up to a 3.2-fold enhancement in the amount of material delivered in 3D spheroids compared to the absence of fuel. The successful transfection of 2D and 3D cell cultures using swarms of LBL PLGA NBs holds great potential for nucleic acid delivery in the context of bladder treatments.

JTD Keywords: Animals, Barrier, Cell line, tumor, Dna, Drug delivery, Drug-delivery, Enzyme catalysis, Gene delivery, Gene transfer techniques, Humans, Lactic acid, Mice, Nanobots, Nanoparticles, Pdna, Plasmids, Polyglycolic acid, Polylactic acid-polyglycolic acid copolymer, Swarming, Transfectio, Transfection, Urease, Urinary bladder neoplasms

We report a new strategy for immunochemical screening of small organic molecules based on the use of a hapten microarray. Using DNA-directed immobilization strategies, we have been able to convert a DNA chip into a hapten microarray by taking advantage of all the benefits of the structural and electrostatic homogeneous properties of DNA. The hapten microarray uses hapten-oligonucleotide probes instead of proteins, avoiding the limitations of preparing stochiometrically-defined protein-oligonucleotide bioconjugates. As proof of concept, we show here the development of a microarray for analysis of anabolic androgenic steroids. The microchip is able to detect several illegal substances with sufficient detectability to be used as a screening method, according to the regulations of the World Anti-Doping Agency for sport and the European Commision for food safety. The results that we show corroborate the universal possibilities of the DNA chip, and, in this case, they open the way to develop hapten microarrays for the immunochemical analysis of small organic molecules.

JTD Keywords: Anti-doping, DNA chip, DNA-directed immobilization (DDI), Fluorescence, Food safety, Hapten microarray, Immunochemical screening, Proof of concept, Small organic molecule, Steroid