TH and Parkinson disease: After intraperitoneal injection to mice, liposomes loaded with levodopa significantly increased the distribution of dopamine (DA) and dihydroxyphenyl acetic acid in the substantia nigra and striata. In a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice model, levodopa-loaded chlorotoxin liposomes significantly attenuated the serious behavioral disorders and diminished the MPTP-induced loss of tyrosine hydroxylase-positive dopaminergic neurons.