Radiation-induced brain injury (RIBI) is a severe, irreversible,
or even life-threatening cerebral complication of radiotherapy in
patients with head and neck tumors, and there is no satisfying prevention
and effective treatment available for these patients. Amifostine (AMF)
is a well-known free radical scavenger with demonstrated effectiveness
in preventing radiation-induced toxicity. However, the limited permeability
of AMF across the blood–brain barrier (BBB) when administered
intravenously reduces the effectiveness of AMF in preventing RIBI.
Herein, we construct a nanoparticle (NP) platform for BBB delivery
of AMF. AMF is conjugated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethylene glycol)]-hydroxy succinamide [DSPE-PEG-NHS,
PEG M 2000], and the product is DSPE-PEG-AMF. Then, the nanoparticles
(DAPP NPs) were formed by self-assembly of poly(lactic-co-glycolic acid) (PLGA), DSPE-PEG-AMF, and polysorbate 80 (PS 80).
PEG shields the nanoparticles from blood clearance by the reticuloendothelial
system and lengthens the drug circulation time. PS 80 is used to encapsulate
nanoparticles for medication delivery to the brain. The results of
our study showed that DAPP NPs were able to effectively penetrate
the blood–brain barrier (BBB) in healthy C57BL/6 mice. Furthermore,
in a well-established mouse model of X-knife-induced brain injury,
treatment with DAPP NPs (corresponding to 250 mg/kg AMF) was found
to significantly reduce the volume of brain necrosis compared to mice
treated with AMF (250 mg/kg). Importantly, the use of DAPP NPs was
also shown to significantly mitigate the effects of radiation-induced
neuronal damage and glial activation. This work presents a convenient
brain-targeted AMF delivery system to achieve effective radioprotection
for the brain, providing a promising strategy with tremendous clinical
translation potential.