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Light INduced Cell control by Exogenous organic semiconductors

Periodic Reporting for period 2 - LINCE (Light INduced Cell control by Exogenous organic semiconductors)

Reporting period: 2020-09-01 to 2022-02-28

LINCE develops light-sensitive devices based on novel functional materials for optical regulation of living cells functions.
The possibility to control the activity of biological systems is a timeless mission for neuroscientists, since it allows both to understand specific functions and to manage dysfunctions. Optical modulation provides, respect to traditional electrical methods, unprecedented spatio-temporal resolution, lower invasiveness, and higher selectivity. However, the vast majority of animal cells does not bear specific sensitivity to light. Search for new materials capable to optically regulate cell activity is thus an extremely hot topic. LINCE will focus on organic semiconductors as ideal candidates, since they are inherently sensitive to visible light and highly biocompatible, sustain both ionic and electronic conduction, can be functionalized with biomolecules and drugs. The application of organic semiconductors in biotechnology will be significantly broadened, to address key, open issues of high biological relevance, in both neuroscience and regenerative medicine. In particular, LINCE develops new devices for: (i) regulation of astrocytes functions, active in many fundamental processes of the central nervous system and in pathological disorders; (ii) control of stem cell differentiation and tissue regeneration; (iii) control of animal behavior, to first assess device biocompatibility and efficacy in vivo. LINCE tools are sensitive to visible and NIR light, flexible, biocompatible, and easily integrated with any standard physiology set-up. They combine electrical, chemical and thermal stimuli, offering high spatio-temporal resolution, reversibility, specificity and yield. The combination of all these features is not achievable by current technologies.
Overall, LINCE will provide neuroscientists and medical doctors with an unprecedented tool-box for in vitro and in vivo investigations.
LINCE specifically targets optical modulation of cells belonging to the huge class of non-excitable cells, because in this field the need for spatio-temporally selective, high throughput and highly effective methods to gain reversible cell activity modulation is extremely urgent. By definition, non-excitable cells are characterized by the inability to generate an all-or-none action potential in response to external stimuli. With the exception of neuron, muscle, and some endocrine cells, all other cells in the body are non-excitable.
During the first 18 months the LINCE team focused onto the possibility (i) to optically modulate astrocyte functions, and (ii) to optically control the cell fate, in terms of proliferation, differentiation and regeneration.
Important results towards these two goals have been already achieved. In more detail, we:
1. developed the fabrication of polymer beads and device architectures for maximizing phototransduction efficiency. Novel materials and devices are under testing with physiologically relevant in vitro cell models;
2. implemented the fabrication of microstructured devices, which act as highly biocompatible and optically active substrates for modulation of primary astrocytes activity (in collaboration with Dr. Valentina Benfenati at CNR, Bologna, Italy);
3. demonstrated that LINCE approach has a beneficial effect on the modulation of endothelial precursors fate determination, in particular on endothelial colony forming cells isolated from the peripheral blood of healthy donors. We observed that cells seeded on active materials and exposed to light show a sizable increase in proliferation and a noticeable enhancement in the formation of the tubular network (in collaboration with Prof. Francesco Moccia at University of Pavia, Italy);
3. preliminarily investigated the effect of optical excitation of active materials onto adipose-tissue derived mesenchymal stem cells and within in vivo Hydra Vulgaris invertebrate models (in collaboration with Dr. Claudia Tortiglione at CNR, Pozzuoli, Italy).

Overall, these first results timely confirm the reliability of the LINCE paradigm, towards the development of unprecedented optoceutic tools.
There is an increasing need of tools capable to selectively modulate, in a spatially and temporally selective manner, the specific functions of diverse, non-excitable cells. Ideally, new technologies should be also minimally invasive and reversible, qualities which cannot be achieved by currently available chemical or electrical cues. Even optogenetic tools, widely employed to modulate the neural activity, have been scarcely applied to non-excitable tissues, being limited by the lack of ion selectivity and inability to extend their spectral sensitivity into the NIR range.
In this framework, LINCE program couples three main ground-breaking elements: the choice of new materials for functional bio-interfaces; the choice of exogenous optical stimulation, as the most suitable technique to provide neuroscientists, biologists and bioengineers with not invasive tools and high spatio-temporal resolution; the selection of specific open issues of high biological relevance and the choice to focus on astrocytes and stem cells, whose precise and selective modulation is currently challenging.
LINCE light addressable interfaces based on organic semiconductors will represent valuable candidates for the toolbox of the neuroscientist and the medical doctor, allowing direct, minimally invasive, selective and rapid control over in vitro cells, during their whole life-span, from genesis to differentiation, to specific function. LINCE will represent a new optical strategy, providing high resolution, selectivity and yield, easily coupled to any standard physiology set-up, without making recourse to highly expensive instrumentation, and avoiding the need for viral transfer. These features will allow for covering a gap currently encountered in the detailed study of astrocytes physiology and in the use of external biophysical stimuli for stem cells differentiation.
In brief, LINCE outcomes are expected to open completely new perspectives for the use of optical stimulation not only in fundamental physiology, but also in the field of regenerative medicine.