Development of Janus hydrogel microcapsules as novel biomaterials-stem cells construct for 3D co-culture applications

Co-cultures of two or more cell types and biodegradable biomaterials of natural origin have been successfully combined to recreate tissue microenvironments. Segregated co-cultures are preferred over conventional mixed ones in order to better control the degree of homotypic and heterotypic interactions. Hydrogel-based systems in particular, have gained much attention to mimic tissue-specific microenvironments and they can be microengineered by innovative bottom-up approaches such as microfluidics. In this study, we developed bi-compartmentalized (Janus) hydrogel microcapsules of methacrylated hyaluronic acid (MeHA)/methacrylated-chitosan (MeCht) blended with marine-origin collagen by droplet-based microfluidics co-flow. Human adipose stem cells (hASCs) and microvascular endothelial cells (hMVECs) were co-encapsulated to create platforms of study relevant for vascularized bone tissue engineering. A specially designed Janus-droplet generator chip was used to fabricate the microcapsules (<250â μm units) and Janus-gradient co-cultures of hASCs: hMVECs were generated in various ratios (90:10; 75:25; 50:50; 25:75; 10:90), through an automated microfluidic flow controller (Elveflow microfluidics system). Such monodisperse 3D co-culture systems were optimized regarding cell number and culture media specific for concomitant maintenance of both phenotypes to establish effective cell-cell (homotypic and heterotypic) and cell-materials interactions. Cellular parameters such as viability, matrix deposition, mineralization and hMVECs re-organization in tube-like structures, were enhanced by blending MeHA/MeCht with marine-origin collagen and increasing hASCs: hMVECs co-culture gradient had significant impact on it. Such Janus hybrid hydrogel microcapsules can be used as a platform to investigate biomaterials interactions with distinct combined cell populations.

Biomimetic superhydrophobic surfaces patterned with wettable spots as implantable chips for in vivo high-content 3D biomaterials response assessment

"Tissue engineering: part A", vol. 21, suppl. 1 (2015)

A 3D computer assisted Orthopedic Surgery Planning approach based on planar radiography

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Informática Médica)

Deposição não eletrolítica de filmes plasmónicos de ouro para biossensores

Dissertação de mestrado em Biofísica e Bionanossistemas

A paisagem nos filmes de Salaviza: entre o fundo e a cena

[Excerto] São múltiplos os entendimentos da paisagem. No quadro da arquitetura, da geografia, da filosofia ou da história da arte, entre outras disciplinas, reclama-se o termo para designar, consoante as abordagens, objetos de natureza muito diversa, gerando-se inevitavelmente ambiguidades de sentido. Importa assim, antes de mais, clarificar, tanto quanto possível, a noção de paisagem de que parto. A paisagem não se cinge a um elemento isolado, nem se confunde com o território ou com o ambiente, tão pouco com a simples representação do espaço. A noção surge designada em diversas línguas como um sufixo que se acrescenta, nomeadamente, à palavra “pays” ou “land” (pays - paysa-ge; land-landscape; land- landschaft). Os Romanos, pode admitir-se, e tal como defende Augustin Berque (2011b), já tinham sensibilidade e pensamento paisageiros. Usavam as palavras topia, associada à pintura (e jardins) e loci, associada ao ambiente, referindo-se com ambas à sua própria cosmofania (...).