Dopamine-Mediated Sclerotization of Regenerated Chitin in Ionic Liquid

Abstract

Abstract:Chitin is a promising structural material for biomedical applications, due to its many advantageous properties and abundance in nature. However, its usage and development in the biomedical field have been stagnant, because of chitin's poor mechanical properties in wet conditions and the difficulties in transforming it into an applicable form. To overcome these challenges, we created a novel biomimetic chitin composite. This regenerated chitin, prepared with ionic liquid, showed improved mechanical properties in wet conditions by mimicking insect cuticle and squid beak sclerotization, i.e., catechol-meditated cross-linking. By ionic liquid-based heat treatment, dopamine oxidation produced melanin-like compounds and dopamine-meditated cross-links without any solvent evaporation and oxidant utilization. The dopamine-meditated sclerotization increased the ultimate tensile strength (UTS) of the regenerated chitin by 2.52-fold, measured after six weeks of phosphate-buffered saline (PBS) submersion. In addition, the linear swelling ratio (LSR) of the chitin film was reduced by about 22%. This strategy raises a possibility of using regenerated chitin as an artificial hard tissue in wet conditions.

Chitosan and hydroxyapatite composite cross‐linked by dopamine has improved anisotropic hydroxyapatite growth and wet mechanical properties

“…Generally, the addition of dopamine increased the cell proliferation when the dopamine used to generate poly(dopamine) coating with low dopamine concentration (<0.02 M) . In contrast, the cell proliferation was slightly reduced when the dopamine used as a cross‐linker with high concentration as in this study (>0.5 M) . Nevertheless, the number of viable cells in the sample that contained dopamine increased, although slightly more slowly than in the other sample.…”

Chitin‐halloysite nanoclay hydrogel composite adsorbent to aqueous heavy metal ions

“…However, in order to further investigate the adsorption mechanism, XPS spectra were determined as shown in Figure for the wide scan of the samples treated with before (a) and after (b) the uptake of Pb 2+ ion. In the wide spectra, typical results of the structural compositions of CT were observed 284.4 eV attributed to all other non‐functionalized sp 2 and sp 3 carbon atoms, and at 399.4 eV to the amine group of CT . In the case of HNC, the wide‐scan spectra showed the characteristic peaks of O1s, Si 2p/2 s, and Al 2p/2 s .…”

The Renewable and Sustainable Conversion of Chitin into a Chiral Nitrogen‐Doped Carbon‐Sheath Nanofiber for Enantioselective Adsorption

“…[15][16][17][18][19][20][21][22][23] However, the processing of chitin into desirable structures or shapes also requires harsh treatments involvingt oxic chemicals because of its intermolecular and interfibrillarh ydrogen bonds, [24][25][26][27] which limits the fabrication of precisely structured chitin-derivedc arbon nanomaterials. [15][16][17][18][19][20][21][22][23] However, the processing of chitin into desirable structures or shapes also requires harsh treatments involvingt oxic chemicals because of its intermolecular and interfibrillarh ydrogen bonds, [24][25][26][27] which limits the fabrication of precisely structured chitin-derivedc arbon nanomaterials.…”

“…As calcium is removed,the helicallyo rdered chemical groups on the surfaceo fe ach chitin nanofiber are recovered. [24][25][26][27][28] The chiral chitin hydrogel was hydrothermally treated at two different temperatures,1 90 and2 10 8C, for 24 h[ Figure 1b At 210 8C, HTC of the chiral chitin hydrogel gave two separate phases,n amely precipitated carbon and an aqueous phase, which is probablyo wing to nanofibril cross-linking ( Figure S6 in the Supporting Information). [38] The amorphous regionso ft he chitin nanofiber retain water [ Figure 1a(iv)].A se vidence, chemically surface-modified chitin nanomaterials (nanowhiskers and deacetylated nanofibers)h ardly show chiral nematic assemblies ( Figure S3 in the Supporting Information) and generally produce nematicphases.…”

“…Many researchers have hypothesized that if chiral chitin [(C 8 H 13 NO 5 ) n ]n anostructures, which occuri nc rustacean and insect cuticles, could be directly and wholly carbonized into nitrogen-doped chiral nanocarbons, it would efficiently and sustainably simplify the chiral nano-construction procedure because chitin is globally the second most abundant biopolymer after cellulose, with approximately 10 10-11 tons produced annually (Figure1a). [15][16][17][18][19][20][21][22][23] However, the processing of chitin into desirable structures or shapes also requires harsh treatments involvingt oxic chemicals because of its intermolecular and interfibrillarh ydrogen bonds, [24][25][26][27] which limits the fabrication of precisely structured chitin-derivedc arbon nanomaterials. Recently,w er eported ac hemical-etching-free approach for the disintegration of chitin nanofibrils from bulk chitin by using calciumi ons that ultimately yieldedachiral nematic chitin hy-drogel withoutt he need for at emplate and hydrolysis with strong acids.…”