Study of Intracellular Metabolism using Nanodiamond Quantum Thermometry

Abstract

This thesis presents a multi-faceted exploration into cellular thermoregulation and immune responses, utilizing advanced nanodiamond quantum thermometry techniques. In Part I, we introduce an innovative intracellular thermometer system employing fluorescent nanodiamonds (FNDs) with specific targeting capabilities for organelles. The system, integrated with a coplanar waveguide (CPW) structure, demonstrates enhanced accuracy and reliability in temperature measurements. By employing antibody-conjugated FNDs, we successfully target mitochondria, nuclei, and membranes, enabling spatially resolved temperature measurements. Real-time tracking reveals a significant temperature increase of approximately 9 °C in mitochondria in response to ATP synthesis disruption, offering profound insights into cellular thermodynamics and metabolism. The FND system, with its high precision and nanoscale resolution, outperforms traditional thermometry methods, Yoobeen Lee Department of Chemistry Hanyang University promising advancements in monitoring cellular states, such as cancer, aging, and inflammation. In Part II, we delve into the dynamics of macrophage polarization and metabolic responses using nanodiamond quantum thermometry. Observations during M1 polarization reveal elevated mitochondrial temperatures, aligning with biochemical pathways linked to Nitric Oxide expression and mitochondrial complex disruption. Conversely, M2 polarization shows distinct metabolic responses, emphasizing the unique characteristics associated with different polarization states. A comparative analysis with previous studies using silica nanobead (SiNB) substrates highlights the novel insights gained through nanodiamond thermometry, emphasizing the importance of substrate characteristics in understanding macrophage behavior. This study contributes to a comprehensive understanding of macrophage responses and their microenvironment, offering potential applications in immunology and therapeutic interventions. In the Appendix, the topographical impact on macrophage behavior is explored, revealing the control exerted by hexagonal arrayed silica nanobead (SiNB) substrates on cellular adhesion, polarization, and cytokine secretion. The manipulation of SiNB scale directs macrophages towards pro-inflammatory or anti-inflammatory phenotypes, implicating the mechanotransduction related pathway in adhesion-induced polarization. This work suggests the potential for designing tissue-engineered biomaterials with tailored immune responses. Overall, this thesis presents an integrated approach to cellular studies, offering valuable insights into both intracellular thermoregulation and immune responses, with broad implications for biomedical research and therapeutic development.