Many proteins have been used for therapeutic purposes due to their high activity and specificity. On the other hand, proteins have several unfavorable physicochemical properties, such as poor solubility, susceptibility to enzymatic degradation, short plasma half-life, immunogenicity, and the tendency to undergo aggregation, adsorption, and denaturation. An exciting and revolutionary strategy to change the physicochemical characteristics of proteins is the conjugation with synthetic polymers. The resulting hybrid materials may exhibit numerous advantages, including improved solubility and stability.