Bionanocomposites: Differential Effects of Cellulose Nanocrystals on Protein Diblock Copolymers

Abstract

We investigate the effects of mixing a colloidal suspension of tunicate-derived cellulose nanocrystals (t-CNCs) with aqueous colloidal suspensions of two protein diblock copolymers, EC and CE, which bear two different self-assembling domains (SADs) derived from elastin (E) and the coiled-coil region of cartilage oligomeric matrix protein (C). The resulting aqueous mixtures reveal improved mechanical integrity for the CE+t-CNC mixture, which exhibits an elastic gel network. This is in contrast to EC+t-CNC, which does not form a gel, indicating that block orientation influences the ability to interact with t-CNCs. Surface analysis and interfacial characterization indicate that the differential mechanical properties of the two samples are due to the prevalent display of the E domain by CE, which interacts more with t-CNCs leading to a stronger network with t-CNCs. On the other hand, EC, which is predominantly C-rich on its surface, does not interact as much with t-CNCs. This suggests that the surface characteristics of the protein polymers, due to folding and self-assembly, are important factors for the interactions with t-CNCs, and a significant influence on the overall mechanical properties. These results have interesting implications for the understanding of cellulose hydrophobic interactions, natural biomaterials and the development of artificially assembled bionanocomposites.

Fate of Cellulose Nanocrystal Aerosols Deposited on the Lung Cell Surface In Vitro

“…To determine the amount of rhodamine attached on the CNCs, the dye concentration in the solutions was plotted against the UV−vis adsorption and the value at the intercept of the resulting graph with the x-axis was used as the amount of rhodamine on the CNCs. 40 Preparation of c-CNCs and t-CNCs Samples. Homogenous and stable suspensions were prepared by dispersing functionalized c-CNCs and t-CNCs at a concentration of 1 mg/mL in ultrapure water via sonication in a 10 mL flat bottom glass flask (Duran Schott, Germany) in an Elmasonic P30.H sonication bath (Elma, Hans Schmidbauer GmbH&CoKG, Singen, Germany) (1 h; frequency 37 kHz, 100% intensity, pulse mode).…”

Current characterization methods for cellulose nanomaterials

“…[403][404][405] The CNMs are modified with either epichlorohydrin followed by Fluolabeled CNC suspension C ammonium hydroxide to form a thiourea bond with the isocyanate, 406,407 are modified with sodium hydroxide to form a thiocarbamate bond with the isocyanate, 408 or is reacted directly with the isothiocyanate using dibutyltindilaurate as a catalyst. [403][404][405] Although this chemistry has been extensively used for biochemical applications and is relatively easy to control, the thiourea and thiocarbamate bonds are unstable in more extreme conditions and may be unsuitable for some biochemical applications. [409][410][411] Further, the use of sodium hydroxide in some of the processes used can desulfate CNCs.…”

The Potential of Cellulose Nanocrystals in Tissue Engineering Strategies

“…These improvements were shown to be depending on the CNCs' concentration and aspect ratio, but also on their surface modification when used within certain polymer matrices. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 46 the presence of CNCs and thus leading to dissimilar physicochemical properties 229 . This work may provide some insights into the design of future bionanocomposites involving peptide-based polymers and…”