Release Rate Optimization in Molecular Communication for Local Nanomachine-Based Targeted Drug Delivery

Targeted drug delivery has become an important direction in anticancer therapy research. In nanomachine-based targeted drug delivery, where a nanomachine containing anticancer drugs moves towards cancer cells and releases drugs to kill cancer cells, it should be noted that the nanomachine has limited space to carry drugs, and on the other hand the cancer cells have finite receptors to bind drugs. Therefore, to efficiently utilize cancer drugs, this paper aims to calculate and optimize drug release rate of nanomachines to produce a full drug response in local targeted drug delivery. A drug reception model reflecting ligand-receptors binding is established based on M/M/c/c queue. The minimum released concentration of drug molecules is derived from the minimum effective occupancy ratio of receptors according to the drug occupancy theory. We then derive the optimized release rates of each nanomachine from the minimum effective concentration of drug molecules according to diffusion channel response in terms of continuous emission of single nanomachine and multi-nanomachine, respectively. The simulation results match well with the analytical results. The study paves the way for designing local targeted drug delivery systems.