The invention provide a new class of silicone-containing prepolymers containing dangling hydrophilic polymer chains. The graph processing module generates group results based on grouping information which identifies groups of individual components. In particular, the apparatus involves a retractor assembly having a pair of opposing blades having a channel adapted to engage an incision in a patient. The selected storage unit is indicated to the donor array as having been donated before the lost information is rebuilt on the selected storage unit.