Retinoic acid-loaded NFL-lipid nanocapsules promote oligodendrogenesis in focal white matter lesion

Abstract

Neural stem cells (NSC) are located in restricted areas of the central nervous system where they self-renew or differentiate into neurons, astrocytes or oligodendrocytes. The stimulation of endogenous NSC differentiation is one of the most promising therapeutic approaches to restore neurological function in patients affected by neurodegenerative diseases. Endogenous NSC of the subventricular zone (SVZ) can be selectively targeted by lipid nanocapsules (LNC) coated with the peptide NFLTBS.40-63 (NFL-LNC) after intra-lateral ventricular injection in the brain. NFL-LNC can potentially deliver active compounds to SVZ-NSC and thus promote their differentiation to treat neurodegenerative diseases. The aim of this work was to induce endogenous NSC differentiation by specifically delivering retinoic acid (RA) to SVZ-NSC via NFL-LNC. RA was successfully encapsulated into NFL-LNC and RA-NFL-LNC were incubated with primary rat SVZ-NSC. In vitro, RA-NFL-LNC decreased the number of nestin+ (NSC marker) cells and neurospheres compared to controls and increased the number of GalC+ (oligodendrocytic marker) cells. Then, RA-NFL-LNC were injected in the right lateral ventricle of a lysolecithin-induced rat focal white matter lesion model to evaluate their impact on oligodendrocyte repopulation and remyelination. RA-NFL-LNC significantly increased the percentage of mature oligodendrocytes, stimulating oligodendrogenesis, nearly to the pre-lesion levels. Thus, RA-NFL-LNC represent a promising nanomedicine to be further investigated in the treatment of demyelinating diseases.