Co‐Assembled and Microfabricated Bioactive Membranes

Abstract

The fabrication of hierarchical and bioactive self‐supporting membranes, which integrate physical and biomolecular elements, using a single‐step process that combines molecular self‐assembly with soft lithography is reported. A positively charged multidomain peptide (with or without the cell‐adhesive sequence arginine‐glycine‐aspartic acid‐serine (RGDS)) self‐assembles with hyaluronic acid (HA), an anionic biopolymer. Optimization of the assembling conditions enables the realization of membranes with well‐controlled and easily tunable features at multiple size scales including peptide sequence, building‐block co‐assembly, membrane thickness, bioactive epitope availability, and topographical pattern morphology. Membrane structure, morphology, and bioactivity are investigated according to temperature, assembly time, and variations in the experimental setup. Furthermore, to evaluate the physical and biomolecular signaling of the self‐assembled microfabricated membranes, rat mesenchymal stem cells are cultured on membranes exhibiting various densities of RGDS and different topographical patterns. Cell adhesion, spreading, and morphology are significantly affected by the surface topographical patterns and the different concentrations of RGDS. The versatility of the combined bottom‐up and top‐down fabrication processes described may permit the development of hierarchical macrostructures with precise biomolecular and physical properties and the opportunity to fine tune them with spatiotemporal control.

Electrostatic self-assembly of polysaccharides into nanofibers

“…Zeta potential ( ) measurements confirmed that both components xanthan and chitosan oligomers have opposite charge and hence, they are able to co-assemble by electrostatic interactions. These type of interactions have been shown essential to drive the self-assembly of interfacial systems [2,5,30,31].…”

“…The structures were fixed in 2.5% (v/v) glutaraldehyde (in phosphate buffer solution (PBS), pH 7.4) for 1 h. The samples were then dehydrated in a graded ethanol series (50, 70, 90, 96 and 100%) followed by immersion in hexamethyldisilazane (HMDS) [2]. For SEM, the specimens were mounted on aluminum stubs and sputtercoated with gold prior to the visualization on a scanning electron microscope Quanta FEG 3D SEM.…”

“…Self-assembly, the ubiquitous process used by nature to create complex nanostructures with outstanding functionalities [1], has been explored for developing bio-inspired materials with enhanced properties such as flexibility, hierarchical order and bioactivity [1][2][3][4][5]. Different material geometries have been produced by selfassembly, including fibers.…”

Sequence Adaptive Peptide–Polysaccharide Nanostructures by Biocatalytic Self-Assembly

“…29 Mata's group described hybrid multifunctional nanofibrous membranes based on electrostatic interactions between the co-assembled cationic peptide and anionic biopolymer (HA). 30 It is clear from these examples that co-assembly between biopolymers and selfassembling peptides can have dramatic effects on materials properties and consequent function. Here, we combine these two areas and investigate whether dynamic peptide-polymer assembly can be achieved.…”

Peptide-based microcapsules obtained by self-assembly and microfluidics as controlled environments for cell culture

“…Examples of external inputs include mechanical forces, such as shear effects 5 , magnetic 6 and electric 7 fields, thermal gradients 8 and chemically 9 or topographically 10 patterned substrates. Although the concept of DSA still remains ambiguous, templated self-assembly (TSA) can be considered as a kind of DSA, in which a prefabricated ''template'' orients and directs the assembling components.…”