Early detection of cardiac fibrosis in diabetic mice by targeting myocardiopathy and matrix metalloproteinase 2

Early detection of myocardial fibrosis in diabetic cardiomyopathy (DCM) has significant clinical implications for diabetes management. In this study, we identified matrix metalloproteinase 2 (MMP2) as a potential biomarker for early fibrosis detection. Based on this finding, we designed a dual-targeting nanoparticle CHP-SPIO-ab MMP2 to specifically target myocardiopathy and MMP2, enabling sensitive fibrosis detection using magnetic resonance imaging (MRI). Our results demonstrate that collagen hyperplasia (early fiber formation) begins to develop in diabetic mice at 12 weeks old, with observable fibrosis occurring at 16 weeks old. Additionally, MMP2 expression significantly up-regulates around collagen starting from 12 weeks of age. T2 MRI analysis revealed significant T2% enhancement in the hearts of 12-week-old diabetic mice following administration of the CHP-SPIO-ab MMP2 probe, indicating noninvasive detection of fiber formation. Furthermore, after fibrosis treatment, a reduction in T2% signal was observed in the hearts of 16-week-old diabetic mice. These findings were supported by Sirius red and Prussian blue staining techniques. Overall, our study presents a promising strategy for early identification of myocardial fibrosis.