An integrated microfluidic device for screening the effective concentration of locally applied tacrolimus for peripheral nerve regeneration.

Bao-Sheng Yin,Wei-Guo Zhang,Ming Li,Shou-Yu Wang,Bo-Ming Liu

doi:10.3892/etm.2014.2082

Abstract

The effectiveness of tacrolimus (FK506) for the promotion of nerve regeneration is known. However, at present, due to the fact that systemic application may lead to opportunistic infections and tumors, and that the treatment of peripheral nerve injury with systemic immunosuppression is not generally accepted, FK506 has not been widely used for the treatment of simple or peripheral nerve injury. In this study, a pyramid-shaped microfluidic device was designed and fabricated that was able to analyze the effective concentration of locally applied FK506. After testing the effectiveness of the microfluidic device by measuring the fluorescence intensity of fluorescein isothiocyanate-dextran, rat Schwann cells (SCs) were loaded into the device and cultured for 9 days in the presence of different concentrations of FK506. SC proliferation in the presence of FK506 was concentration-dependent between 0 and 2.5±0.003 ng/ml. The proliferation rate reached a maximum at 1.786±0.014 ng/ml, which was statistically significantly different from the proliferation rate at lower FK506 concentrations. There was no statistically significant difference in the proliferation rate between the 1.786 ng/ml group and groups of higher FK506 concentrations. Furthermore, the SCs in the microfluidic device and a 96-well plate continued to proliferate as the culture time increased. No statistically significant differences were identified between the microfluidic device and a 96-well plate with regard to the proliferation rates in each corresponding group. The results obtained in this study demonstrated that the microfluidic device can be used as an excellent platform for the study of drug concentration at the cellular level, and the effective FK506 concentration for local application is 1.786±0.014 ng/ml.

Highlights

The repair of peripheral nervous system (PNS) damage resulting from trauma, excessive stretching and even iatrogenic injury is a tremendous challenge for clinical medicine as the recovery of nerve function may be poor due to broken end distortion following nerve anastomosis and scar ingrowth, ineffective nerve regeneration and slow regeneration
Microfluidic devices integrate the preparation of pharmaceutical compositions, separation, detection, cell culture and other basic operations into a very small chip [14]
The experimental conditions were controlled by changing the concentration of the FK506 solution, and the risk of contamination was minimal

Summary

Introduction

The repair of peripheral nervous system (PNS) damage resulting from trauma, excessive stretching and even iatrogenic injury is a tremendous challenge for clinical medicine as the recovery of nerve function may be poor due to broken end distortion following nerve anastomosis and scar ingrowth, ineffective nerve regeneration and slow regeneration. Tacrolimus (FK506) is a macrolide immunosuppressant approved by the US Food and Drug Administration It plays a role in immunosuppression and in the effective promotion of nerve regeneration. A stable cell culture environment can be constituted and maintained by a continuous medium supply and waste removal system that resembles the human circulatory system. It reduces the number of cells required and the requirement for large volumes of culture medium and costly reagents, which makes the microfluidic device an attractive platform for high-throughput screening [7,8]. Rat Schwann cells (SCs) were loaded into the device and the optimum concentration of FK506 was determined with the aim of providing an experimental and theoretical reference for the therapy of peripheral nerve injury

Materials and methods

Results

Discussion