Natural Plant Tissue with Bioinspired Nano Amyloid and Hydroxyapatite as Green Scaffolds for Bone Regeneration

Bone defects have been increasingly prevalent around the globe and traditional bone substitutes are constantly limited by low abundance and biosafety due to their animal-based resources. Plant-based scaffolds are currently studied as a green candidate but the bioinertia of cellulose to mammalian cells leads to uncertain bone regeneration. Inspired by the cross-kingdom adhesion of plants and bacteria, this work proposes a concept of a novel plant bone substitute, involving coating decellularized plant with nano amyloids and nano hydroxyapatites, to bridge the plant scaffold and animal tissue regeneration. Natural microporosity of plants can guide alignment of mammalian cells into various organ-like structures. Taking advantage of the bioactive nano amyloids, the scaffolds drastically promote cell adhesion, viability, and proliferation. The enhanced bio-affinity is elucidated as positively charged nano amyloids and serum deposition on the nanostructure. Nano-hydroxyapatite crystals deposited on amyloid further prompt osteogenic differentiation of pre-osteoblasts. In vivo experiments prove successful trabeculae regeneration in the scaffold. Such a hierarchical design leverages the dedicated microstructure of natural plants and high bioactivity of nano amyloid/hydroxyapatite coatings, and addresses the abundant resource of bone substitutes. Not limited to their current application, plant materials functionalized with nano amyloid/hydroxyapatite coatings allow many cross-kingdom tissue engineering and biomedical applications.

Automated summary

Bone defects are a growing problem worldwide, and traditional bone substitutes have limitations due to their limited resources and biosafety concerns. Plant-based scaffolds are being studied as an environmentally friendly alternative, but their bioinertia to mammalian cells hampers bone regeneration. This study proposes a novel concept of a plant bone substitute that involves coating decellularized plants with nano amyloids and nano hydroxyapatites, facilitating the connection between plant scaffolds and animal tissue regeneration. The natural microporosity of plants guides the alignment of mammalian cells and the bioactive nano amyloids drastically improve cell adhesion, viability, and proliferation. Furthermore, nano-hydroxyapatite crystals deposited on the amyloid promote osteogenic differentiation. In vivo experiments demonstrate successful trabeculae regeneration in the scaffold. This hierarchical design harnesses the unique microstructure of natural plants and the high bioactivity of the nano amyloid/hydroxyapatite coatings, providing an abundant resource for bone substitutes. Additionally, plant materials functionalized with these coatings have potential applications in tissue engineering and biomedical fields beyond bone regeneration.