Bioengineering of nanostructured systems based on nature-inspired surfaces for regeneration of human tissues

• Autor(a) principal: Lopes, Flávia Daniela Santos
• 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/10773/28293
• topic: Biomimetic; Superhydrophobic-superhydrophilic surfaces; Layer by-Layer; Freestanding micro-membranes; Modular tissue engineering

Modular tissue engineering aims to mimic the complexity of native tissue with well-defined 3D architectures and synergistic interactions of various cell lines by generating repeated functional modular units that will be assembled into a functional tissue. These modular blocks should exhibit specific microstructural characteristics to mimic the complex architecture of native tissues. For the direct production of modular units, patterned superhydrophobic-superhydrophilic (SH-SL) surfaces have emerged as promising platforms for scalable manufacturing of microscale modular units to develop functional tissues designed by the bottom-up approach. In this sense, and inspired by the Lotus effect, the present work aims at the production of freestanding (FS) stratificated micromembranes based on polyl- lysine (PLL) and alginate (ALG) biopolymers through the Layer-by-Layer (LbL) methodology. For this purpose, initially microscale SH-SL surfaces with different geometric shapes were developed. Subsequently, alginate hydrogels were formed in situ by the standing droplet method in the SL areas that served as a sacrificial template to the production of freestanding membranes by sequential deposition of electrolytes through electrostatic interactions. Regarding the deposition conditions of the polymers, in the zeta potential analysis, the charges of each compound were verified, while the quartz microbalance (QCM-D) showed the electrostatic interaction between PLL and ALG. ATR-FTIR analysis confirmed the presence of polymers in the resulting membrane. After detachment, the resulting membranes crosslinked with genipin (GnP) to improve mechanical properties to promote cell adhesion and proliferation. Biological assays with human umbilical vein endothelial cells (HUVECs) and human adipose stem cells (hASCs) showed that the crosslinked [PLL / ALG]100 membranes show cellular viability.