Brownian dynamics simulation of insulin microsphere formation from break-up of a fractal network.
Motivated by a recent experiment on insulin microsphere formation where polyethylene glycol (PEG) is used as the precipitating agent, we have developed a simple theoretical model that can predict the formation of a fractal network of insulin monomers and the subsequent break-up of the fractal network into microsphere aggregates. In our approach the effect of PEG on insulin is modeled via a standard depletion attraction mechanism via the Asakura-Oosawa model. We show that even in the context of this simple model, it is possible to mimic important aspects of the insulin experiment in a brownian dynamics simulation. We simulate the effect of changing temperature in our model by changing the well depth of the Asakura-Oosawa potential. A fractal network is observed in a "deep quench" of the system, followed by a "heating" that results in a break-up of the network and subsequent formation of microspheres.
Department of Physics, Lehigh University, Bethlehem, Pennslyvania 18015, USA.
Wei
W
Li
J D
JD
Gunton
Siddique J
SJ
Khan
J K
JK
Schoelz
A
A
Chakrabarti
D007328:Insulin / Q000737:chemistry*; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D011092:Polyethylene Glycols / Q000737:chemistry*
D007328:Insulin; D011092:Polyethylene Glycols