Single Input Multi Output Model of Molecular Communication via Diffusion With Spheroidal Receivers

Spheroids are aggregates of cells that can mimic the cellular organization often found in tissues. Spheroids can be created from various cell types, including cancer cells, stem cells, and primary cells, and they serve as valuable tools in biological research. Although there are initial results on how a molecular signal can propagate between a pair of spheroids, practical experiments typically use clusters of spheroids and there isn’t a good understanding of how neighboring spheroids impact the spatiotemporal dynamics of local molecule propagation. This paper simulates a series of scenarios to gain intuition about propagation in such multi-spheroid systems for applications such as transport and drug delivery. The spheroids are modeled as porous media with a corresponding effective diffusion coefficient. System variations are considered with a higher spheroid porosity (i.e., with a higher effective diffusion coefficient) and molecule uptake by the spheroid cells (approximated as a first-order degradation reaction while molecules diffuse within the spheroid). Results show that a local crowd of spheroids will eventually slow overall propagation, such that molecules stay in the vicinity of the transmitter for longer. The results demonstrate that a single-spheroid receiver model is insufficient to accurately model propagation under these conditions.