  Breast cancer is the most common type of cancer observed in women.
Communication with the tumor microenvironment allows invading breast cancer
cells, such as triple negative breast cancer cells, to adapt to specific
substrates. The substrate topography modulates the cellular behavior, among
other factors. A number of different materials and micro/nanofabrication
techniques have been employed to develop substrates for cell culturing.
Silicon-based substrates present a lot of advantages as they are amenable to a
wide range of processing techniques and they permit rigorous control over the
surface structure. We investigate and compare the response of triple negative
breast cancer cells (MDA-MB-231) on laser-patterned silicon substrates with two
different topographical scales, i.e., the micro- and the nanoscale, in the
absence of any other biochemical modification. We develop silicon surfaces with
distinct morphological characteristics by employing two laser systems with
different pulse durations (nanosecond and femtosecond) and different processing
environments (vacuum, SF6 gas, and water). Our findings demonstrate that
surfaces with micro-topography are repellent, while surfaces with
nano-topography are attractive for MDA-MB-231 cell adherence.
