TYMP and mitochondrial neurogastrointestinal encephalomyopathy: TsX reconstituted proteopolymersomes are also used to deliver thymidine phosphorylase (TP) as an enzyme therapy strategy for mitochondrial neurogastrointestinal encephalomyopathy, where TsX functions as a channel to allow for the transport of enzyme substrate thymidine and product thymine through the polymersome.