Disclosed is agents and methods that target metabolism malfunctions, inborne as well as acquired, as well as methods for preparation of the agents. In particular, the invention relates to methods for preparing molecular imprinted polymers with high binding capacity for phenylalanine or tyrosine, MIPs that bind phenylalanine or tyrosine, and methods for treating phenylketonuria, alkaptonuria, and hypertyrosinemia.
