The goal of this CAREER proposal is to develop a predictive theory for gel stability by discovering and elucidating the underlying mechanisms of the sudden collapse of colloidal gels. Such research is important for the rational design of soft biomaterials, such as injectable drug delivery platforms and transplantable tissue scaffolds to patients whose body cannot generate such tissue. The development of such theory is potentially transformative, because it would establish qualitative understanding of gel collapse.
Injectable gels have emerged in the past decade as a premier tool in tissue engineering and drug delivery due to their biocompatibility, tunability to different therapeutic moieties, and minimally invasive delivery. However, such gels are susceptible to sudden failure ? without warning the scaffold collapses into a dense, structureless sediment. In that case, the transport of active compounds is dramatically curtailed, and the scaffold-like structural support is lost. It is not currently possible to predict gel collapse owing to the difficulty of detailed observation of collapse, the computational expense of simulating large-scale gel evolution, and limited theory of arrested colloidal dynamics. This study will create a window through which to view, in exacting detail of particle and network rearrangements, the real-time collapse, as it occurs. This will yield a phase map that, for the first time, predicts the collapse and the characteristic length scale, age, attraction and underlying forces that lead to collapse.
