A biodegradable cross-linked cationic multi-block copolymer of linear polyethylenimine wherein the LPEI blocks are linked together by hydrophilic linkers with a biodegradable disulfide bond and methods of making thereof. Each range bin for each scan line is associated with a rectangular grid location to determine the character located in the grid location and the background color and foreground color for the grid location. The first region has an isoelectric point exceeding the second region’s isoelectric point. Methods of making the fiber optic connectors and other structures are also disclosed.