Synthetic Neurons and Artificial Photoactivated Synapses

The brain is a complex network of inter-connected neurons that communicate through synapses.

SYNAPS aims to for the first time mimic such synapses using liposomes as artificial cells, and visible light to trigger a signal from a ‘sender’- to a ‘receiver’-liposome.

Mimicking such communication processes will help with understanding how complex natural emergent properties arise, and could ultimately allow for the construction of a chemical computer.

SYNAPS will excel beyond the state-of-the-art by maintaining chemical isolation between liposome interiors, ensuring local, time-bound communication between connected liposomes, and using light as an external stimulus and fuel.

These concepts are essential to construct artificial tissues that can communicate on an individual liposome-to-liposome basis, in contrast to the state-of-the-art where communication generally occurs with the bulk solution.

To achieve this, a messenger compound will be locally photosynthesised through transmembrane electron transfer by porphyrin dimers that portray a charge-transfer excited state.

The liposomes will be organised into a synaptic cleft through the use of synthetic complementary clustering compounds that provide stable adhesion between sender and receiver liposomes.

The messenger compound will be recognised by reversible and selective membrane-spanning receptors in the receiver liposome, that will output the signal through fluorescence.

In addition, a reaction cascade network will be constructed involving the messenger to produce an artificial action potential, that is, a transient peak in the concentration of the messenger, ensuring a time-bound dissipative signal.

Altogether, SYNAPS will provide advances in systems chemistry by providing a nanoscale platform for communication between chemically isolated systems, but also results that are useful for applications such as light-to-chemical energy conversion, chemical sensing and smart drug-delivery.