The development of drug delivery systems (DDS) for targeted intracel-
lular delivery of therapeutic agents has been attracting great deal of
attention. In traumatic central nervous system conditions, where thera-
pies have been revealing to be highly inneficient and non-specific, these
targeted DDS could be highly beneficial. We have previously shown
in vitro studies where the carboxymethylchitosan (CMCht)/ poly(amido-
amine) (PAMAM) nanoparticles (NPs) were able to be uptaken by dif-
ferent cell types (neurons and glial cells), while not evidencing any
cytotoxicity. In the present study, in vivo biodistribution of the CMCht/
PAMAM NPs was investigated. Following intravenous injection in adult
male Wistar rats, the NPs showed to be stable in circulation and able to
be internalized by cells from different tissues (e.g., brain, liver, kidney
and lung). Afterwards, methylprednisolone (MP)-loaded fluorescently-
labelled NPs were administered in the cerebrospinal fluid of the cis-
terna magna of adult male Wistar rats. Upon the intracisternal injec-
tion, NPs were detected throughout the cortical and parenchimal areas
of the brain, namely in the prefrontal cortex, hippocampus and peri-
ventricular areas after 24 h. More recently, ongoing studies are focusing
on the therapeutic value of these methylprednisolone-loaded NPs
administered following a spinal cord lesion in rats. Significant differ-
ences in the BBB locomotory test were found in MP-NPs treated rats 1monthafterinjury