3. Non-ionic dextran methacrylate (dex-MA) hydrogel is prepared by photopolymerization through crosslinking of methacrylate bonds (see figure). The hydrogel is prepared with 10% (w/v) of dex-MA (i.e. 90% water) and is allowed to swell to equilibrium state. The equilibrium swelling shows water content 10 times of the initial water content (i.e. relaxed state after hydrogel formation). Based on the data provided below, calculate the molecular weight between the crosslinks (Mc) and crosslinking density (px, #/volume) the hydrogel using Peppas-Merill Equation. Which molecular design of polymer can be changed to alter the swelling character of the hydrogel? Dextran Methacrylate X-linked Dextran Methacrylate hydrogel Dextran Photopolymerizable methacrylate bond Photo Polymerization X-links Molecular weight of dextran methacrylate (M) = 16 10 Da Dextran methacrylate/water Interaction parameter (x) = 0.47 Molar volume of water (V) = 18 cm/g Specific volume of polymer (sp,2) = 0.62 cm/g O HO HO