Fabrication of two-dimensional (2D) shape-tailored microparticles using wettability contrast-based platforms

• Autor(a) principal: Neto, Mafalda Dias de Campos
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/30126
• topic: Microparticle design; Advanced cell carriers; Ultra-thin polymeric particles; Patterned surfaces; Wettable-dewettable contrasts

For several decades microparticles have been exclusively and extensively explored as spherical drug delivery vehicles and large-scale cell expansion carriers. More recently, microparticulate structures gained interest in broader bioengineering fields, integrating a myriad of strategies that include bottom-up tissue engineering, three-dimensional (3D) bioprinting, and development of tissue/disease models. The concept of bulk spherical micrometric particles as adequate supports for cell culture has been challenged, and systems with finely tuned geometric designs and (bio)chemical/physical features are current key players in impacting technologies. In this sense, the discovery of twodimensional (2D) materials led to the breakthrough of a multitude of different low dimensional structures with very unique properties, namely (i) high surface areato-volume ratio, (ii) sub-micrometer thickness, (iii) heterofunctionality and (iv) non-covalent adhesiveness, which surpass their bulk counterparts. Although their development regarding tunable lateral-dimensions and geometries remains challenging, pre-patterned platforms had gain significant attention in addressing such drawback. Herein, resorting to wettability contrast patterned surfaces, different nanometer-thick particles of various sizes and geometries (e.g. squares, circles, triangles, hexagons) with high precision and definition were developed. These ultrathin quasi-2D polymeric microparticles in contact with cells allow the generation of gravity-enforced human adipose-derived stems cells spheroids without impairing their natural morphology. Cell culture for 3 days maintain cells viable, metabolically active and an increase in the release of angiogenic factors, namely VEGF.