Layer-by-Layer Deposition of Low-Solid Nanochitin Emulgels Creates Porous Structures for High Cell Attachment and Proliferation

Abstract

Direct ink writing (DIW) is a customizable platform to engineer complex constructs from biobased colloids. However, the latter usually display strong interactions with water and lack interparticle connectivity, limiting one-step processing into hierarchically porous structures. We overcome such challenges by using low-solid emulgel inks stabilized by chitin nanofibrils (nanochitin, NCh). By using complementary characterization platforms, we reveal NCh structuring into spatially controlled three-dimensional (3D) materials that generate multiscale porosities defined by emulsion droplet size, ice templating, and DIW infill density. The extrusion variables, key in the development of surface and mechanical features of printed architectures, are comprehensively analyzed by using molecular dynamics and other simulation approaches. The obtained scaffolds are shown for their hierarchical porous structures, high areal density, and surface stiffness, which lead to excellent modulation of cell adhesion, proliferation, and differentiation, as tested with mouse dermal fibroblast expressing green fluorescent proteins.

Chitin Nanofibers Enable the Colloidal Dispersion of Carbon Nanomaterials in Aqueous Phase and Hybrid Material Coassembly

“…54 The visualization of the hydrophobic effect involved the characterization of the contour of inverse fluctuation density, which was calculated for all heavy atoms within a cavity with a radius of 0.33 nm in every grid with 0.1 nm size. 15,33,35 The standard binding free energy calculation was carried out to evaluate the affinity between the hydrophobic surface and CNTs using the methodology proposed in a prior study. The colvars executive files were generated by using BFEE2 package.…”

“…14 Tailoring interparticle interactions without compromising CNT integrity can be alternatively achieved by adjusting solvency or incorporating additives. 15 In this context, ChNF is hypothesized to endow colloidal stability and tunable surface characteristics that modulate the charge balance through the ChNF's degree of deacetylation and pH of the medium. 16 Although few attempts have explored this promise, by using other polysaccharide structures, such as nanocellulose and carboxymethylcellulose, 17,18 the mechanism responsible for colloidal stabilization remains poorly understood.…”