| Heterogeneities (e.g., asymmetry, non-randomness, microdomains, mesoscopic formations, various compartments) in biomembranes existing at all different scales and associated dynamics are the driving forces for functionalities. They are the focus of modern biomembrane research after the fluid mosaic model. The dynamics of signaling, such as interactions between membrane receptors and lipid molecules or microdomains (so-called lipid rafts), plays an essential role for many cellular processes (e.g., surface-initiated apoptosis). Understanding the dynamics is crucial to obtaining a comprehensive idea of cellular processes and to designing approaches for the management and control by modulating membrane physical properties. Modern biophotonic techniques are powerful tools as they could probe the dynamics in situ or in vivo. In this work, we applied a label-free Raman spectroscopic method to detect dynamics in single lipid vesicles and elucidated ceramide-related rafts remodeling. Further, to preserve native membrane including local asymmetric micro-structures and compartments while reducing complexities of cells, we developed methods to create and characterize micrometer-sized reduced cells, which can be patterned to make hybrid systems on micro-arrays for potential high-throughput analytical assays. For cellular plasma membranes, we used in vivo laser scanning fluorescent confocal microscopy to probe the supramolecular interactions of lipid rafts and death receptor (Fas), providing insights of membrane remodeling during apoptosis. |
