Nanotopography and nanomechanical properties of nanostructured chitosan scaffolds and of cells adhered on them

• Grant number: 20/05632-9
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): September 01, 2020
• Effective date (End): August 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal researcher: Denise Freitas Siqueira Petri
• Grantee: Rafael Leonardo Cruz Gomes da Silva
• Home Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/13492-2 - Synthetic and natural scaffolds applied to regenerative medicine, AP.TEM

Abstract

Chitosan has been widely used as scaffolds for cell adhesion and proliferation. However, it is unclear how the surface nanotopography and nanomechanical properties of chitosan scaffolds affect fibroblasts attachment and proliferation. Nanoimprinting, electrospinning, laser ablation are common techniques applied for nanostructuring of scaffolds. Nevertheless, they require specific instruments and the nanostructuring area is limited. This project proposes a simple methodology for the production of chitosan scaffolds with tunable topographies and mechanical properties for further evaluation of fibroblasts adhesion, migration and proliferation on them. The creation of patterns onto the surface of vanillin cross-linked chitosan films will take place by evaporation or polymerization of hydrophobic emulsified domains with controlled size. The crosslinking and patterning of chitosan scaffolds will be a one-step procedure. N-hexane domains are potential candidates for the production of nanometric cavities by evaporation, whereas domains of methyl methacrylate monomer (neat or mixed with ethylene glycol dimethacrylate) will be polymerized in order to create protuberances with different mechanical properties (Figure 1). The resulting scaffolds will be evaluated from a qualitative (size, morphology and reproducibility of the structures) and quantitative point of view (swelling degree, topography and mechanical properties). AFM based techniques will be applied to determine the topography and mechanical properties of the scaffolds. Afterward, the effect of different topographies and mechanical properties of the scaffolds on the in vitro mechanotransduction of fibroblasts and on the biomechanical properties of adhered cells will be evaluated. (AU)