Team:Groningen/Template/MODULE/project/MBD/bandage

Our main goal for this project is to design a bandage prototype for burn wounds. Burn wounds are mainly infected with S. aureus and P. aeruginosa. The quorum molecules produced by these two pathogens should diffuse through the bandage and activate the production of Nisin, Aiia and DspB proteins. These three proteins should diffuse out of the bandage and act on the pathogens.

To evaluate different bandage designs, we develop a multi-scale dynamic model of the bandage. The bandage is discretized into lattices where each lattice contains differential equations describing the growth of bacteria, production of nisin, production of Aiia, production of DspB and the detection of quorum molecules. Apart from the differential equations for the productions of the three IPM molecules we also consider the diffusion parameters. This makes the model more dynamic to study characteristics of our bandage.

Each state variable in each lattice is initialized according to the different bandage designs. Each lattice contains few bacteria which uses glucose as nutrient source and grows. Actively growing bacteria produce Nisin, Aiia and DspB only in response to the quorum molecules produced by both Staphylococcus aureus and Pseudomonas aeruginosa. In presence of quorum molecules in the lattice, the bacteria starts producing Nisin, Aiia and DspB. Nisin, Aiia and DspB produced in a lattice diffuses to nearby lattices until equilibrium is reached.

Studying the diffusion rates of Nisin, Aiia and DspB is important to estimate the time taken to reach the threshold concentrations. The threshold concentration is the minimum concentration of the proteins that is required to breakdown biofilm, kill S. aureus and quorum quench P. aeruginosa population. The diffusion constants for these three proteins were not available directly. For more info on the rate equations look here.