title: Liquid marbles for high-throughput biological screening of anchorage-dependent cells.
abstract: Stable liquid marbles (LM) are produced by coating liquid droplets with a hydrophobic powder. The used hydrophobic powder is produced by fluorosi-lanization of diatomaceous earth, used before to produce superhydrophobic structures. Here, the use of LM is proposed for high-throughput drug screening on anchorage-dependent cells. To provide the required cell adhesion sites inside the liquid environment of LM, surface-modified poly(l-lactic acid) microparticles are used. A simple method that takes advantage from LM appealing features is presented, such as the ability to inject liquid on LM without disrupting (self-healing ability), and to monitor color changes inside of LM. After promoting cell adhesion, a cytotoxic screening test is performed as a proof of concept. Fe(3+) is used as a model cytotoxic agent and is injected on LM. After incubation, AlamarBlue reagent is injected and used to assess the presence of viable cells, by monitoring color change from blue to red. Color intensity is measured by image processing and the analysis of pictures takes using an ordinary digital camera. The proposed method is fully validated in counterpoint to an MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carbo​xymethoxyphenyl)-2-(4-sulfophenyl)-2H-te​trazolium) colorimetric assay, a well-known method used for the cytotoxicity assessment.
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Zona Industrial da Granja, S. Cláudio do Barco, 4806-909, Caldas das Taipas, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
authors.forename: Nuno M
authors.initials: NM
authors.lastname: Oliveira
authors.forename: Clara R
authors.initials: CR
authors.lastname: Correia
authors.forename: Rui L
authors.initials: RL
authors.lastname: Reis
authors.forename: João F
authors.initials: JF
authors.lastname: Mano
mesh_terms: D000818:Animals; D002119:Calcium Carbonate / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D007692:Diatomaceous Earth / Q000494:pharmacology; D057166:High-Throughput Screening Assays / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D007501:Iron / Q000032:analysis; D019344:Lactic Acid / Q000737:chemistry; D051379:Mice; D010316:Particle Size; D011091:Polyesters; D011108:Polymers / Q000737:chemistry
chemical_list: D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D007692:Diatomaceous Earth; D007501:Iron; D002119:Calcium Carbonate
keywords: high-throughput screening; hydrophobicity; image processing; liquid marbles; microbioreactors