Scientists developing new biomaterials often try to mimic the body’s natural proteins, but a chemist shows that simpler polymers — based on a handful of plastic building blocks — also work well. Using AI, her team was able to design polymer mixtures that replicate simple protein functions within biological fluids. The random heteropolymers dissolve and stabilize proteins and can support cells’ normal protein-making machinery. The technique could speed the design of materials for biomedical applications.