Native and Complexed IGF-1 : Biodistribution and Pharmacokinetics in Infantile Neuronal Ceroid Lipofuscinosis

Abstract EN

Infantile neuronal ceroid lipofuscinosis (INCL) is a severe neurodegenerative disorder of childhood characterized by selective death of cortical neurons.

Insulin-like growth factor 1 (IGF-1) is important in embryonic development and is considered as a potential therapeutic agent for several disorders of peripheral and central nervous systems.

In circulation IGF-1 is mainly bound to its carrier protein IGFBP-3.

As a therapeutic agent IGF-1 has shown to be more active as free than complexed form.

However, this may cause side effects during the prolonged treatment.

In addition to IGFBP-3 the bioavailability of IGF-1 can be modulated by using mesoporous silicon nanoparticles (NPs) which are optimal carriers for sustained release of unstable peptide hormones like IGF-1.

In this study we compared biodistribution, pharmacokinetics, and bioavailability of radiolabeled free IGF-1, IGF-1/IGFBP-3, and IGF-1/NP complexes in a Cln1-/- knockout mouse model.

IGF-1/NP was mainly accumulated in liver and spleen in all studied time points, whereas minor and more constant amounts were measured in other organs compared to free IGF-1 or IGF-1/IGFBP-3.

Also concentration of IGF-1/NP in blood was relatively high and stable during studied time points suggesting continuous release of IGF-1 from the particles.