Another drug delivery system that has shown potential for chemotactic applicability is protocells. In general, protocells are artificial cells that mimic living cells but cannot reproduce and have genetic mutations like living cells do. Moreover, protocells combine the advantages of liposomes with that of mesoporous silica nanoparticles. These advantages include but are not limited to stability, large capacity for various cargos, low toxicity, immunogenicity, and the ability to circulate the blood for long periods. Thus, researchers aim to create a tunable chemotactic protocell that can move towards or away from a chemical signal. In fact, researchers have devised a way to use the enzymes catalase, urease, and ATPase to move the protocell closer or further away from the reactant, giving them direction and movement control of these protocells. Overall, the development of chemotactic controlled protocols holds great promise for the targeted delivery of drugs to specific areas of the body, potentially increasing treatment efficacy while minimizing side effects. However, more research is needed to fully understand the capabilities and limitations of protocells as drug delivery systems and optimize their design and functionality for specific applications.