Cross-linked alginate-polyalkylene glycol polymer coatings for encapsulation and methods of making the same

A method of forming a biocompatible capsule, comprising:

• forming a covalently stabilized coating encapsulating a biological material, said forming step comprising:
• providing an aqueous solution having said biological material suspended therein, said aqueous solution further comprising a reactant dissolved therein, said reactant selected from the group consisting of:
• (i) alginate-[polyalkylene glycol (PAG)-X1]n,
• (ii) multi-functional PAG-X2, and
• (iii) both;
• and
• reacting alginate-[PAG-X1]n with multi-functional PAG-X2 in said aqueous solution, wherein n is an integer greater than 0, a first one of X1 and X2 is N3, and a second one of X1 and X2 is selected from the group consisting of:
• wherein R1=CH3, CH2CH3, CH(CH3)2,
• R2=N(CH3)2, OCH3, OH, CH3, H, F, Cl, Br or NO2, and
• R3=OCH3, CH3, H, F, Cl, and NO2.