2025, Vol. 29 ›› Issue (28): 6070-6082

Oriented electrostatically spun polycaprolactone/silk fibroin scaffold loaded with calcium titanate promotes peripheral nerve regeneration

Liu Xiaojun1, 2, Shang Yuqing3, Guan Wenchao3, Xu Linlin1, 2, Li Guicai3   

Abstract: BACKGROUND: Oriented polycaprolactone/silk fibroin blend electrospinning scaffolds can repair peripheral nerve damage and promote nerve regeneration, but the repair effect is limited, and it is necessary to further combine bioactive materials, growth factors, and other factors to prepare bionic neural scaffolds. Calcium titanate nanoparticles have the ability to promote adhesion between Schwann cells and have been widely used in the field of biomedical materials.
OBJECTIVE: To prepare polycaprolactone/silk fibroin-calcium titanate functionalized scaffolds by electrospinning technology, and to further explore the effect of the scaffold on Schwann cell viability and adhesion.
METHODS: Polycaprolactone/silk fibroin scaffolds were prepared by electrospinning technology. The optimal parameters were selected by adjusting the syringe flow rate, receiving device speed and spinning time during the preparation process for subsequent experiments. Under the optimal parameters, randomly oriented polycaprolactone/silk fibroin scaffolds (denoted as PCL/SF-R), oriented polycaprolactone/silk fibroin scaffolds (denoted as CTO-0), and oriented polycaprolactone/silk fibroin scaffolds containing 0.1, 0.5, and 1.0 mg/mL polydopamine modified calcium titanate (denoted as CTO-1, CTO-5, and CTO-10, respectively) were prepared by electrospinning technology. The physical properties of the five groups of scaffolds were characterized. The extracts of the five groups of scaffolds were co-cultured with rat fibroblast cell line (L929). Cell proliferation was detected by MTT assay. Rat Schwann cell line (RSC96) was inoculated on the five groups of scaffolds. Cell viability, cytoskeleton staining, and cytoskeleton and cell adhesion related genes were detected.
RESULTS AND CONCLUSION: (1) The optimal parameters for preparing electrospinning scaffolds were as follows: syringe flow rate 15 µL/min, receiving device speed 1 800 r/min, and spinning time 1 hour. (2) The PCL/SF-R group had the largest water contact angle and the smallest elastic modulus, while the CTO-0 group had the smallest water contact angle and the largest elastic modulus. The degradation rate of the scaffolds in the CTO-0 group was lower than that in the CTO-1 group, and the degradation rate of the scaffolds decreased with the increase of the mass concentration of calcium titanate in the oriented scaffolds. (3) The scaffolds in the five groups had no toxic effects on L929 cells and had good biocompatibility. CCK-8 assay results showed that CTO-10 could improve the viability of RSC96 cells. Cytoskeleton staining results showed that the aspect ratio and cell protrusion length of cells on the oriented scaffolds were higher than those on the randomly oriented scaffolds. qPCR test results showed that the mRNA expressions of YAP and Cntn2 in the CTO-5 and CTO-0 groups were higher than those in the PCL/SF-R group (P < 0.05). (4) The results indicate that the oriented polycaprolactone/silk fibroin-calcium titanate scaffold has good biocompatibility, mechanical properties, and hydrophilicity, which can enhance the viability and migration ability of Schwann cells and promote peripheral nerve regeneration.

Key words: calcium titanate, aligned electrospinning, polycaprolactone, silk fibroin, peripheral nerve regeneration, engineered neural material