Recently, the nanofiber research team led by Yu Jianyong, academician of Donghua University Textile Science and technology innovation center and Ding Bin researcher has made important progress in the research field of inorganic nano fibrous elastic tissue engineering scaffold. The related results are published in the "3D Superelastic Scaffolds Constructed from Flexible Inorganic Nanofibers with Self-fitting Capability Self-fitting".

For irregular bone defects or bone defects at the junction of cartilage, tendon, ligament and other soft tissues, it is a great challenge in clinical medicine.

Autogenous bone or inorganic material used for bone repair is hard and brittle, which is difficult to match and fit irregular bone defect area, which affects the effect of bone repair.

The elastic scaffold material can be compressed and reduced and implanted into the body, greatly reducing the wound. After implantation, it has a unique advantage in the field of bone repair.

Inorganic components and nanofiber structure of bone extracellular matrix are the key factors to promote bone formation. Therefore, three-dimensional scaffolds with inorganic nanofibers as the main body and shape recovery performance will become potential scaffolds for bone tissue engineering.

However, inorganic materials are generally hard and brittle, and few can be processed into fibers, making it difficult to construct three-dimensional fibrous elastic scaffolds.

The research team designed and manufactured a three-dimensional fiber elastic scaffold, which is mainly composed of flexible inorganic nanofibers and can be recovered in body fluid.

The research team has prepared a SiO2 nanofiber membrane, which is flexible like silk, through the sol-gel electrospinning process. The fiber membrane can be folded and expanded without breakage, and the nanofiber can bend 180 degrees without breaking.

The team further prepared flexible SiO2 nanofiber composite chitosan solution through homogeneous dispersion freeze drying to prepare a super elastic SiO2 nanofiber chitosan (SiO2 NF-CS) three-dimensional scaffold.

Flexible SiO2 nanofibers and SiO2NF-CS three-dimensional fiber scaffolds

The scaffold can completely restore to the initial height and porous structure under 80% strain cyclic compression in water environment. It has quick recovery and 10000 times compression cycle.

Good resilience enables SiO2 NF-CS fibrous scaffolds to implant different shapes of rabbit mandibular defects in compressed state. After absorption of body fluid, it can quickly restore to the initial shape and close to the bone defect area.

At the same time, SiO2 NF-CS scaffold can improve the repair effect of cranium injury in rats.

By further controlling the ratio of SiO2 nanofibers and chitosan in different regions, the researchers constructed gradient fiber scaffolds from organic to inorganic, from soft to hard, showing great potential in bone defect repair at soft tissue and bone interface.

In vivo adaptation and bone repair properties of elastic SiO2NF-CS fiber scaffolds

In this work, flexible inorganic nanofibers are introduced into the development and design of elastic materials for bone tissue engineering scaffolds. Minimally invasive implantation is achieved, and surgical wounds are reduced. At the same time, bone regeneration is accelerated, the process of bone healing is accelerated, and the pain of patients with bone injury is reduced. This provides guidance and reference for the research and design of new bone repair materials.