https://phys.org/news/2019-01-velcro-human-cells.html

The team of researchers, which also included the groups of Prof. Dr. Gerald Radziwill and Prof. Dr. Wolfgang Schamel, focussed their attention on an important class of receptors – called integrins – that facilitate adhesion to extracellular matrix. "Although integrins have central roles in many normal biological processes, they can also promote growth and spread of cancer and have thus been explored as targets for anti-cancer therapies." explains first author Julia Baaske.

To control integrin-mediated adhesion using light, the scientists first developed an OptoMatrix coated with a light-sensitive plant protein called phytochrome B. Then they engineered an OptoIntegrin equipped with a phytochrome-interacting factor (PIF6) and expressed this receptor in cancer cells. Phytochrome B is usually found in its inactive form, but when exposed to a specific wavelength of red light it is activated and can be bound by PIF6; when exposed to infrared light it switches back to the inactive form. "The most exciting experiment was when we first shone red light on the OptoMatrix: the cells expressing OptoIntegrin immediately adhered to the matrix and activated intracellular signalling processes. Then when we used infrared light, they almost completely detached." explains Baaske. "Essentially, we have developed light-controlled velcro for human cells".