Metformin loaded injectable silk fibroin microsphere for the treatment of spinal cord injury

Abstract

The repair of spinal cord injury is a great challenge in clinical. Improving the microenvironment of the injured site is the key strategy for accelerating axon regeneration and synaptic formation. Herein, a kind of silk fibroin microspheres functionalized by metformin through dopamine was developed using water-in-oil emulsification-diffusion method and surface modification technique, and the effect on cortical neuron was evaluated. The results showed that the microspheres showed a uniform size distribution with the diameter of around 60 μm and a concave structure. Moreover, the microspheres possessed good injectability and stability. In addition, the metformin could be successfully immobilized in the silk fibroin microspheres. The cell culture results displayed that the growth and morphology of cortical neurons on the microspheres with metformin concentration of 5 mg/mL and 10 mg/mL were obviously better than that on other samples. Notably, the spread area of single cortical cell on silk fibroin microspheres was increased with the ascending metformin concentration. Therefore, the results indicated that the metformin loaded silk fibroin microsphere could obviously improve the growth and spreading behavior of cortical neuron. The study may provide an important experimental basis for the development of drug loaded injectable biomaterials scaffolds for the treatment of spinal cord injury and have great potential for spinal cord regeneration.

Keywords:

• Spinal cord injury
• silk fibroin
• microsphere
• metformin
• injectable

Acknowledgment

The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (32171352, 31771054), Natural Key Science Research Program of Jiangsu Education Department (19KJA320006).

CRediT authorship contribution statement

Qi Han: Methodology, Validation, Software, Investigation, Tiantian Zheng, Guicai Li: Investigation, Formal analysis, Writing - review & editing, Linliang Wu, Qi Han, Linhui Zhang, Ningling Wu, Jiaqi Liang: Formal analysis, Visualization, Hong Wu, Guicai Li: Conceptualization, Writing - original draft, Writing - review & editing, Supervision, Project administration.

Data availability statement

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.

Code availability

The code generated during the current study is available from the corresponding author on reasonable request

Disclosure statement

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Additional information

Funding

This work was funded by National Natural Science Foundation of China (32171352, 31771054), Natural Key Science Research Program of Jiangsu Education Department (19KJA320006)