Mechanically Strong Chitin Fibers with Nanofibril Structure, Biocompatibility, and Biodegradability

Abstract

The environment-friendly fibers fabricated from natural polysaccharides have attracted much attention in the development of sustainable materials, owing to the global pollution caused by fibers and textiles fabricated from petroleum-based polymers. Chitin derived from seafood wastes possesses excellent biocompatibility and biodegradability, but it is still far from being fully explored. Here, we designed and prepared, for the first time, chitin fibers with nanofibril structures from the chitin solution in the NaOH/urea aqueous system by cooling on a lab-scale wet-spinning machine. Because of the slow diffusion of phytic acid into the chitin dope, the stiff chitin chains could self-aggregate sufficiently in a parallel manner to form the nanofibers via a "bottom-up" approach and then be bundled into the gel-state fibers. The dried chitin fibers were demonstrated to be composed of nanofibers with a mean diameter of 27 nm and exhibited a tensile strength of 2.33 cN/dtex, which is higher than those reported in the literature. Interestingly, with an increase of the draw ratio from 1.0 to 1.8, the crystal index (χ c ) and degree of orientation (Π) increased very slightly, whereas the tensile strength and Young's modulus of the chitin fibers enhanced significantly, suggesting that a relatively perfect nanofibrous structure existed in all of the chitin fibers with and without drawing. Moreover, the chitin fibers were validated to support the adhesion and growth of ventricular myocytes as a cardiac tissue scaffold showing good biocompatibility. Furthermore, the complete biodegradation time of the chitin fibers in soil and in vitro could be extrapolated from experimental data to be approximately 22 and 34 days, respectively, indicating good biodegradability. This work would lead to a great potential of chitin in the applications including absorbable surgical suture, hemostasis and fixation medical device, and so forth, where biodegradability is required.

A Strong, Tough, and Scalable Structural Material from Fast‐Growing Bamboo

“…Furthermore, the two key structural properties—strength and toughness—tend to be mutually exclusive in structural material design, in which strong materials are usually brittle, whereas tough materials are frequently weak . To address this challenge, tremendous efforts have been devoted in developing bioinspired structural materials that can offer the combination of both strength and toughness at low density (i.e., lightweight) while also manufactured at high volume and low cost …”

Anisotropic nanocomposite films of hydroxypropylcellulose and graphene oxide with multi-responsiveness

“…Aqueous HPC solution with concentration of 50 wt% was prepared by dissolving prescribed amount of HPC in water, according to the protocol described elsewhere. 4 To prepare the mixture solutions of HPC and GO, prescribed amounts (Table S1 †) of GO solution (1.2 mg mL À1 ), HPC powder, and water were added into a glass vessel, which were kept in a 4 C refrigerator and stirred every day for 2 weeks. 31 GO-HPC solutions were blade-coated on a at polyimide lm (thickness of 0.125 mm) at room temperature and 40% environmental relative humidity (RH), by using an XT-300 coating machine (Shijiazhuang Oschina Mechanical Technology Co., Ltd) with a shear rate of 100 s À1 .…”

“…1 Myriad functional cellulose-based materials, including advanced densied woods and regenerated cellulose materials, have been developed with promising applications in textiles, water treatment, tissue engineering, exible electronics, and so forth. [2][3][4] Especially, the new dissolution and regeneration technology and surface modication strategies greatly improve the processability and solubility, and enrich the functionalities. Besides the cellulose nanocrystals and nanobrils, [5][6][7][8][9] cellulose derivatives have tailored functions by molecular modication and can be dispersed in solvents or other polymers at the molecular level.…”

Microfibers synthesized by wet-spinning of chitin nanomaterials: mechanical, structural and cell proliferation properties

“…Though various techniques have been explored for chitin spinning, the general rules are the same: a harsh, non-green solvent is necessary in order to break down the hydrogen bonds in the material and to dissolve the molecules, aer which a coagulant or anti-solvent can be used to recrystallize chitin. 5,6 The solvent can be an ionic liquid, N,N-dimethylacetamide/LiCl, CaCl 2 /methanol, alkali/urea. 1 A reasonable alternative, however is to directly exploit the nanostructure of chitin in the design and development of high-order constructs while minimizing or avoiding dissolution (and subsequent regeneration).…”

“…26 Recently, Zhu et al have investigated the myocyte attachment and beating on the chitin bers in brinogen/Matrigel hydrogel made by solution spinning, showing a great potential of chitin in cardiac applications. 6 Additional relevance to the medical eld is in the manufacture of sutures, which become in contact with different tissues present in the biological environment, such as bone and tendon, heart muscle in cardiac surgeries and skin in wound healing. 27,28 In sum, the results so far indicate that chitin offers promise as a microber structure and have a great potential for surgical suturing and tissue healing.…”