Inspired by nature, collagen is an outstanding polypeptide utilized to exploit its bioactivity and material design for healthcare technologies. In this study, we describe the self-aggregation of water-dispersible nanocollagen helices upon solidification to fabricate different forms of natural collagen materials. Chemically extracted native collagen fibrils are uniform anisotropic nanoparticles with an average diameter of about 50 nm and a high aspect ratio. The as-prepared collagen nanofibrils are soluble in sodium acetate-acetic acid buffer and are dispersible in water, thus generating collagen liquids that are used as distinct biopolymer precursors for materials development. Our interesting findings indicate that water-dispersible collagen-derived alcogels undergo critical point drying to self-arrange hierarchical nanofibrils into helix bundles in collagen sponge-like aerogels. Notably, using lyophilization to remove water in the biopolymer dispersion, a full regeneration of solidified fibers is achieved, producing collagen aerogels with lightweight characteristics similar to natural cottons. The self-aggregation of water-dispersible collagen occurs under freeze-drying conditions to turn individual nanofibrils into sheets with layered structures in the aerogel networks. The development of transparent, water resistant collagen bioplastic-like membranes was achieved by supramolecular self-assembly of water-dispersible collagen nanofibrils. Our efforts present a reliable concept in soft matter for creating promising collagen examples of liquids, hydrogels, aerogels, and membranes to increase utilization value of native collagen for biomedicine, pharmaceuticals, cosmetics, and nutrients.

中文翻译：

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水分散性纳米胶原螺旋的自聚集

受自然界的启发，胶原蛋白是一种出色的多肽，可用于开发其生物活性和用于医疗保健技术的材料设计。在这项研究中，我们描述了水分散性纳米胶原螺旋固化后的自聚集，以制造不同形式的天然胶原材料。化学提取的天然胶原原纤维是均匀的各向异性纳米粒子，平均直径约为50 nm，且纵横比较高。所制备的胶原纳米原纤维可溶于乙酸钠-乙酸缓冲液中并且可分散在水中，从而产生胶原液体，其被用作用于材料开发的独特生物聚合物前体。我们有趣的发现表明，水分散性胶原蛋白衍生的凝胶经过临界点干燥，以将胶原纳米状气凝胶中的纳米纤维自动排列成螺旋束。值得注意的是，使用冻干法去除生物聚合物分散体中的水分，可以实现固化纤维的完全再生，从而生产出具有类似于天然棉的轻质特性的胶原蛋白气凝胶。水分散性胶原蛋白的自聚集在冷冻干燥条件下发生，以将单个纳米纤维转变成在气凝胶网络中具有分层结构的薄片。通过超分子自组装水分散性胶原纳米原纤维，实现了透明，防水的胶原生物塑料样膜的开发。