Influence of engineered nanoparticles (ENPs) on cytoskeletal remodeling of human dermal fibroblasts (HDF) in geometrical constraints

• Main Author: Ng, Alina Wenhui
• Other Authors: Dalton Tay Chor Yong
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Medicine, Health and Life Sciences; Micropatterning; TiO2 nanoparticles; Human dermal fibroblast cells; Cytoskeletal remodeling
• Online Access: https://hdl.handle.net/10356/176178
• Institution: Nanyang Technological University

In contemporary times, engineered nanoparticles (ENPs) have been utilized globally due to their extensive and promising properties. They have emerged as indispensable tools across various industries, owing to their remarkable ability to be finely tuned to various specific application requirements. By manipulating their physicochemical attributes, nanoparticles offer unparalleled versatility, rendering them pivotal in domains ranging from environmental remediation to medical therapeutic care. Given the proliferation of such innovations, it is critical to understand the potential effects of NPs on cellular behavior. Currently, multiple studies have mainly reported results based on the NP’s physicochemical properties and their effect on nano safety. However, these studies lack sufficient information to comprehensively understand the interactions of NPs within the cellular cytoskeleton. The cellular cytoskeleton comprises a dynamic meshwork of protein filaments essential for maintaining cellular architecture, facilitating intracellular transport, and enabling cell movement. It participates in fundamental cellular processes, encompassing not only basic functions like cell division and migration but also complex activities such as embryonic development and wound healing. To delve into a further understanding of the influence of NPs on cellular behavior, this study aims to examine the extent in which the cytoskeletal structure gets altered between one where the cytoskeleton has yet to fully develop (preloaded NPs sample group) and a mature cytoskeleton (post-loaded/ normally administered NPs sample group). Intriguingly, the actin organization of the preloaded sample group was observed to be more diffused. We then further hypothesized that only certain stress fibers within the actin organization are more susceptible to the influence of the uptake of NPs. Hence, to test our hypothesis, single cell micropatterning was adopted in this study, where human dermal fibroblast (HDF) cells were confined into various geometrical architectures (circle, square, rectangle of AR 5:1 and 10:1) to further investigate on the influence of cytoskeletal response to the uptake of NPs at a molecular level. This approach was taken because it had previously been reported that different cell shapes give rise to different stress fibers. Our results have shown that dorsal stress fibers (dSF) and transverse arcs (tA) of the preloaded HDF cells’ cytoskeleton were significantly influenced by the uptake of ENPs to a much greater extent than post-loaded samples. This poses implications for cell development, as the transfer of NPs load from one cell to 2 daughter cells during cell division may lead to perturbations in cytoskeletal remodeling.