Oral nanoparticle-encapsulated enzyme replacement therapy for mucopolysaccharidosis type I (MPS-I): a proof of concept study

Mucopolysaccharidosis type I (MPS-I) is a rare, multisystemic lysosomal storage disease (LSD) caused by mutations in the IDUA gene, which encodes the enzyme alpha-L-iduronidase. Current treatments include hematopoietic stem cell transplantation and enzyme replacement therapy (ERT), administered via weekly intravenous infusions. ERT is of limited efficacy owing to its inability to reach critical tissues such as the brain and bone. To address these limitations, this study explores a novel method to improve drug delivery to target organs and simplify administration: oral administration of enzyme encapsulated within nanostructured lipid carriers (NLC). Encapsulation of ERT within NLC enabled effective oral administration. In vitro analysis showed that our NLC formulation was as effective as intravenous ERT in correcting enzyme activity and reducing glycosaminoglycan (GAG) accumulation in fibroblasts from MPS-I patients, when administered periodically. Permeability studies confirmed passage across the intestinal barrier. Proteomic analyses demonstrated normalization of protein expression in energetic pathways related to hexose metabolism, and significant improvements in protein dysregulation in the cytoskeleton, cellular trafficking, lysosomal function, GAG biosynthesis and degradation, and the extracellular matrix. Furthermore, in vivo studies in MPS-I knockout (KO) mice demonstrated biodistribution of NLC-encapsulated enzymes to all tissues affected by the disease, including passage across the blood-brain barrier and access to poorly vascularized bone. These findings suggest that oral administration of ERT via NLC encapsulation represents a significant advancement in MPS-I treatment, enabling drug delivery to previously inaccessible areas. This study opens important avenues of research for future therapeutic strategies targeting LSDs.