title: Quasi-spherical microwells on superhydrophobic substrates for long term culture of multicellular spheroids and high throughput assays.
abstract: Multicellular tumour spheroids closely recapitulate the physiological environment of tumour tissues. However, their implementation in drug screening assays remains limited due to the technological challenges of forming large numbers of high quality spheroids in platforms compatible with high throughput screening. A simple bench-top microfabrication strategy is demonstrated here based on the principle of ice lithography carried out on superhydrophobic substrates to fabricate quasi-spherical microwells (spheriwells). The microwells shapes and dimensions are directly controlled by the hydrophobicity of the substrate and the volume of the water droplets. The prepared concave microwells enable the formation of dense and homogeneous multicellular tumour spheroids. Spheroids formed within spheriwells are trapped within the microwells, which eliminate loss during media manipulation and facilitate long-term on-chip culture. Morphological and phenotypical changes associated with the growth of MCF-7 adenocarcinoma cells in spheriwells were characterised using imaging flow cytometry and revealed the appearance of heterogeneous populations with loss of E-Cadherin expression. The compatibility of the spheriwells with an on-chip MTT assay is demonstrated. The very unusual shape of the spheriwells, prepared using materials and methods routinely used in most research laboratories, provides a straightforward and scalable platform to prepare high quality multicellular tumour spheroids compatible with high throughput biological screening assays.
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, Adelaide SA 5095, Australia.
authors.forename: Tianqing
authors.initials: T
authors.lastname: Liu
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, Adelaide SA 5095, Australia.
authors.forename: Marnie
authors.initials: M
authors.lastname: Winter
authors.affiliation: Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, Adelaide SA 5095, Australia. Electronic address: benjamin.thierry@unisa.edu.au.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Thierry
mesh_terms: D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D001672:Biocompatible Materials / Q000138:chemical synthesis; D002478:Cells, Cultured; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005434:Flow Cytometry / Q000295:instrumentation*; D057166:High-Throughput Screening Assays / Q000295:instrumentation*; D006801:Humans; D061986:MCF-7 Cells; D013499:Surface Properties; D046888:Tissue Array Analysis / Q000295:instrumentation*
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; C013830:baysilon
keywords: Drug screening; Ice lithography; Imaging flow cytometry; Microwells; Multicellular tumour spheroids