Electroacupuncture Enhances Mesenchymal Stem Cell Therapy via Improved Perfusion and Inflammation Modulation in Peripheral Nerve Injury: An IVIM-MRI Study in Rats

Junfeng Li¹Qiuyi Chen¹Jintong Pan^1,2Fanqi Meng¹Wensheng Huang³Yingying Liang⁴Xuewen Yu⁴Ruirui Qi¹Peiyin Luo¹Haodong Qin⁵Yueyao Chen^1*Xiaofeng Lin^6*

• ¹Department of Radiology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine (Shenzhen Traditional Chinese Medicine Hospital), Shenzhen, China
• ²Department of Nephrology, Shenzhen Hengsheng Hospital, Shenzhen, China
• ³Department of Radiology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
• ⁴Department of Pathology, The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine (Shenzhen Traditional Chinese Medicine Hospital), Shenzhen, China
• ⁵MR Research Collaboration, Siemens Healthineers, Shanghai, China
• ⁶Department of Nuclear Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China

Background: Stem cells are widely applied in peripheral nerve repair; however, their therapeutic potential is constrained by immune rejection, inflammatory responses, and a poor regenerative microenvironment. Therefore, reducing the inflammatory response, improving the regenerative environment and dynamically monitoring these processes by imaging techniques are critical. This study examined the effectiveness of electroacupuncture (EA) and bone mesenchymal stem cells (BMSCs) on acute sciatic nerve injury in rats. By employing intravoxel incoherent motion (IVIM) MRI, the study monitored perfusion and explored how EA improves the regenerative environment to optimize stem cell transplantation outcomes. Methods: Seventy-two rats were randomly assigned to four groups: EA, EA + BMSCs, BMSCs, and PBS. EA was applied at GB30 and ST36. IVIM-MRI (perfusion fraction f), T2WI, histological staining, immunostaining (CD31, IL-1α, IL-10, PPARγ), and SFI were used to evaluate treatment effects. Results: At 2-4 weeks, the nerve perfusion fraction f in the EA group recovered faster than in the BMSCs group (P < 0.05, Figure 3A). By week 4, the EA group showed the greatest myelin regeneration and nerve fiber restoration (P < 0.05, Figure 5C and Figure 7). The expression of vascular marker CD31 and anti-inflammatory markers IL-10 and PPARγ increased (P < 0.05, Figure 8A and C-D), while pro-inflammatory marker IL-1α decreased in the EA and EA + BMSCs groups (P < 0.05, Figure 8B). Furthermore, f values were strongly correlated with histological and functional outcomes (P < 0.05, Supplementary Figure 1). Conclusion: EA is more effective than BMSCs alone in promoting nerve repair, enhancing blood flow, and reducing inflammation. Moreover, EA enhances the anti-inflammatory effects of BMSCs. The perfusion fraction (f) is a sensitive biomarker for evaluating nerve repair and perfusion restoration.