Biofabrication with Chitosan

Abstract

The traditional motivation for integrating biological components into microfabricated devices has been to create biosensors that meld the molecular recognition capabilities of biology with the signal processing capabilities of electronic devices. However, a different motivation is emerging; biological components are being explored to radically change how fabrication is achieved at the micro- and nanoscales. Here we review biofabrication, the use of biological materials for fabrication, and focus on three specific biofabrication approaches: directed assembly, where localized external stimuli are employed to guide assembly; enzymatic assembly, where selective biocatalysts are enlisted to build macromolecular structure; and self-assembly, where information internal to the biological material guides its own assembly. Also reviewed are recent results with the aminopolysaccharide chitosan, a material that offers a combination of properties uniquely suited for biofabrication. In particular, chitosan can be directed to assemble in response to locally applied electrical signals, and the chitosan backbone provides sites that can be employed for the assembly of proteins, nucleic acids, and virus particles.

Towards area‐based in vitro metabolic engineering: Assembly of Pfs enzyme onto patterned microfabricated chips

“…[10][11][12][13][14][15][16] Second, tyrosinase activates accessible tyrosine residues of the C-terminal pentatyrosine pro-tag into reactive o-quinones, which then covalently link to the nucleophilic amine groups of chitosan to form the protein-chitosan conjugate. [16][17][18][19][20] Chitosan confers its pH-responsive properties to the protein upon covalent conjugation.…”

Removal of copper(II) from sugar-cane spirits employing chitosan

“…This basicity gives chitosan singular properties; chitosan is soluble in aqueous acidic media at pH lower than 6.5 and when dissolved possesses high positive charge on -NH 3 groups (Figure 1). 30 In this work the conditional pH of the samples was verified before and after the treatment with chitosan, observing no change in these values of cachaça samples (in both cases, before and after, the pH kept close to 6, and the chitosan was maintained as started form (powder), because its lower solubility in 40% v/v ethanol medium).…”

Polysaccarides-based gels and solid-state electronic devices with memresistive properties: Synergy between polyaniline electrochemistry and biology

“…The acetic acid concentration (2% w/w) used for chitosan solubilization and gelification should give a pH value (2.4) capable to preserve, in theory, PANI in conductive state. In our experimental conditions, chitosan (pKa 6.3) formed quaternary nitrogen salts becoming a water-soluble cationic polyelectrolyte, 30 whose counter ion, being involved in the charge balance, is the anion acetate. The protonation of amino groups of chitosan shifted the acetic acid dissociation equilibrium towards the anion acetate formation.…”