The chemical composition of scaffolds is similar to the extracellular matrix of the target tissue, but sometimes scaffolds cannot meet the special functional requirements for the initial stage of engineering tissue, such as mechanical and optical properties. Bionic scaffolds require certain levels of supramolecular structure, textile structure and liquid crystal structure. Here, we will focus our attention on animal tissues with a similar high-level structure to that of the target organization and we hope to achieve the desired results through new technical means. In this study, we have developed a method to obtain a fish scale lamellar matrix from grass carp scales. The fine structure of the scale matrix has been studied, and it was found that the grass carp scale matrix is a textured structure consisting of multiple collagen sheets, which have a double-twisted spiral structure similar to a liquid crystal, thus correcting the literature reports of a single twisted spiral structure. Interestingly, this structure has many similarities with the cornea, cementum and tibial matrix. At the same time, the correlation between the etching time and the optical properties of the scaffold was also studied, and the scale matrix can reach light transmission and refraction levels similar to those of the corneal stroma. Moreover, the matrix has good mechanical properties, in vitro anti-enzymatic abilities and compatibility with human corneal epithelial cells. Therefore, this kind of scaffold material and preparation method, with a lamellar structure and special physical parameters, may provide new hope for corneal prosthesis.

To construct a novel artificial cornea biomaterial, a method to prepare collagen lamellar matrix was developed in this study using grass carp scales as raw materials. The relationship between the structure of fish scale collagen lamellar matrix and the optical and mechanical properties was analyzed, and co-culture of it and rat bone marrow mesenchymal stem cells (BMSCs) was performed to preliminarily analyze the cellular compatibility of fish scale collagen lamellar matrix. The results show that the grass carp scales could be divided into base region, lateral region and parietal region according to the surface morphology. The inorganic calcium in the surface layer could be effectively removed by decalcification, and the decalcification rate could reach 99%. After etching treatment, homogeneous collagen lamellar matrix could be obtained. With the decalcification and etching treatment, the water content of the sample increased gradually, but the cross-linking treatment had no obvious effect on the water content of fish scale collagen lamellar matrix. Fish scale collagen lamellar matrix has good transparency, refractive index, mechanical properties and cellular compatibility, which may represent a prospect for the construction of cornea tissue engineering products.

The topographic cues of the extracellular matrix may have significant effects upon cellular behavior, such as adhesion, spreading, migration, proliferation, differentiation, and in particular, morphology and orientation. In this study, we examined the effects of microgrooved collagen membrane (MCM) on mesenchymal stem cell (MSC) behavior. The MCM (9 μm in periodicity, and 1–2 μm in depth) was fabricated on an untreated (nonpolar) and smooth polystyrene substrate, based on the absorption and self-assembly properties of collagen on the polystyrene substrate. Methyl thiazolyl tetrazolium assay revealed that cell proliferation on the MCM was enhanced compared with the smooth collagen membrane at day 2. Qualitative observation of MSC behavior using confocal laser scanning microscopy and scanning electron microscopy showed that MSCs grew with a highly elongated morphology and were aligned strictly along the direction of the microgrooves. Additionally, scanning electron microscopy revealed the oriented cells produced a collagenous matrix on the MCM that had a preferential orientation, whereas the collagenous matrix produced by randomly oriented MSCs on the smooth collagen membrane was disorganized. Future studies should investigate the fabrication of oriented topographical substrates, based on the natural biomaterial collagen, to guide cell alignment and oriented growth along definite directions. These substrates may help produce aligned collagenous matrices that could have good potential for the production of tissue substitutes.

To evaluate a novel lamellar structural biomaterial as a potential biomaterial for guided bone regeneration, we describe the preparation of a collagen membrane with high mechanical strength and anti-enzyme degradation ability by using the multi-level structure of Ctenopharyngodon idella scales. The physical and chemical properties, in vitro degradation, biocompatibility, and in vivo osteogenic activity were preliminarily evaluated. In conclusion, it was shown that the multi-layered collagen structure material had sufficient mechanical properties, biocompatibility, and osteogenic ability. Meanwhile, it is also shown that there is a gap in current clinical needs, between the guided tissue regeneration membrane and the one being used. Therefore, this study provides useful insights into the efforts being made to design and adjust the microstructure to balance its mechanical properties, degradation rate, and osteogenic activity.