International Journal of Nanomedicine (Mar 2022)
Cyclic Strain Mitigates Nanoparticle Internalization by Vascular Smooth Muscle Cells
Abstract
Chia-Liang Tsai,1 Ching-Yun Huang,2 Yi-Ching Lu,1 Li-Mei Pai,3,4 Daniel Horák,5 Yunn-Hwa Ma1,6 1Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, 33302, Taiwan, Republic of China; 2Institute of Biomedical Sciences, Chang Gung University, Taoyuan, 33302, Taiwan, Republic of China; 3Department of Biochemistry & Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan, Republic of China; 4Liver Research Center, Chang Gung Memorial Hospital, Taoyuan, 33305, Taiwan, Republic of China; 5Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague 6, 162 06, Czech Republic; 6Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, 33305, Taiwan, Republic of ChinaCorrespondence: Yunn-Hwa Ma, Department of Physiology and Pharmacology, Chang Gung University, Guishan, Taoyuan, 33302, Taiwan, Republic of China, Email [email protected]: Intravascular delivery of nanoparticles for theranostic application permits direct interaction of nanoparticles and vascular cells. Since vascular smooth muscle cells (VSMCs), the major components of the vascular wall, are constantly subjected to mechanical stimulation from hemodynamic influence, we asked whether cyclic strain may modulate internalization of magnetic nanoparticles (MNPs) by cultured VSMCs.Methods: Cyclic strain (1 Hz and 10%) was applied with Flexcell system in cultured VSMCs from rats, with cell-associated MNPs (MNPcell) determined by a colorimetric iron assay. Transmission and scanning electron microscopy were used for morphology studies. Confocal microscopy was used to demonstrate distribution of actin assembly in VSMCs.Results: Incubation of poly(acrylic acid) (PAA)-coated MNPs with VSMCs for 4 h induced microvilli formation and MNP internalization. Application of cyclic strain for 4– 12 h significantly reduced MNPcell by up to 65% (p < 0.05), which was associated with blunted microvilli and reduced vesicle size/cell, but not vesicle numbers/cell. Confocal microscopy demonstrated that both cyclic strain and fibronectin coating of the culture plate reduced internalized MNPs, which were co-localized with vinculin. Furthermore, cytochalasin D reduced MNPcell, suggesting a role of actin polymerization in MNP uptake by VSMCs; however, a myosin II ATPase inhibitor, blebbistatin, exhibited no effect. Cyclic strain also attenuated uptake of PAA-MNPs by LN-229 cells and uptake of poly-L-lysine-coated MNPs by VSMCs.Conclusion: In such a dynamic milieu, cyclic strain may impede cellular internalization of nanocarriers, which spares the nanocarriers and augments their delivery to the target site in the lumen of vessels or outside of the circulatory system.Graphical Abstract: Keywords: cyclic strain, magnetic nanoparticles, endocytosis, actin
