AFM Characterization of the Internal Mammary Artery as a Novel Target for Arterial Stiffening

Abstract

Using the atomic force microscopy- (AFM-) PeakForce quantitative nanomechanical mapping (QNM) technique, we have previously shown that the adventitia of the human internal mammary artery (IMA), tested under dehydrated conditions, is altered in patients with a high degree of arterial stiffening. In this study, we explored the nanoscale elastic modulus of the tunica media of the IMA in hydrated and dehydrated conditions from the patients with low and high arterial stiffening, as assessed in vivo by carotid-femoral pulse wave velocity (PWV). In both hydrated and dehydrated conditions, the medial layer was significantly stiffer in the high PWV group. The elastic modulus of the hydrated and dehydrated tunica media was significantly correlated with PWV. In the hydrated condition, the expression activity of certain small leucine-rich repeat proteoglycans (SLRPs), which are associated with arterial stiffening, were found to be negatively correlated to the medial elastic modulus. We also compared the data with our previous work on the IMA adventitia. We found that the hydrated media and dehydrated adventitia are both suitable for reflecting the development of arterial stiffening and SLRP expression. This comprehensive study of the nanomechanical properties integrated with the proteomic analysis in the IMAs demonstrates the possibility of linking structural properties and function in small biological samples with novel AFM methods. The IMA is a suitable target for predicting arterial stiffening.

Review: Advanced Atomic Force Microscopy Modes for Biomedical Research

“…Many pathologcial conditions have been investigated with AFM including articular cartilage and osteoarthritis, cancer, Alzheimer’s Disease, and viruses such as HIV [ 136 ]. More examples include identifying novel drug targets in drug discovery [ 137 ], imaging collagen fibrils of the cornea in vision science [ 138 ], characterization of internal mammary artery [ 139 ], and dental studies of fluoride treatment on phosphoric acid-etching in primary teeth [ 140 ]. As the reviewed imaging capabilities become more matured and commercialized, more research studies in the biomedical area are expected to make use of AFM as a powerful tool.…”