In the first part of the talk, I will explain the role of cell mechanics (i.e. exerted forces) and phagocytic activity during wound repair and pathogen/particle clearance. I will show the development of a novel technique that uses extensive photobleaching-induced apoptosis to study the repair response of lung epithelial tissue. This model consists of a small injury area wherein apoptotic cells are still intact.^[1] Our findings reveal that individual epithelial cells are able to clear dead cells by applying a pushing force, whilst macrophages actively phagocytose the dead cells to create an empty space. I will also demonstrate that this repair mechanism is hampered when nanoparticles such as carbon nanotubes (CNTs) are internalized by epithelial cells, which is hypothesized to be due to the increase of cellular traction force, which impedes cell migration. Moreover, I will show the phagocytic activity of macrophages during particle clearance using a particle surface.^[2] In particular, the ability of macrophages to adhere and migrate on the particle surface, and mechanically remove the particles in their vicinity will be shown. The latter is important for example to understand how macrophages sense and clear pathogens which adhere to tissue or implant surfaces.

In the second part of the talk, I will describe our effort to produce a biological laser.^[3] I will explain how we are able to engineer single biological cells to carry gain medium (e.g. fluorescent dyes) and support light amplification without the need of a conventional optical cavity. Generation of intracellular lasing activity is a powerful approach capable of supporting potential applications in the field of cell imaging and cell identification studies.

References:

1. D. Septiadi et al., Adv. Mater., 2018, 1806181
2. D. Septiadi et al., Adv. Mater., 2020, under review
3. D. Septiadi et al., Adv. Opt. Mater, 2020, accepted