Development and evaluation of polymer nanoparticles for oral delivery of estradiol to rat brain in a model of Alzheimer's pathology

PLA/PLGA nanoparticles for delivery of drugs across the blood-brain barrier

“…Carotid artery administration was proven to be more effective than intravenous administration for brain delivery as expected, because NPs could be transported directly to the brain after carotid artery administration [18] . In comparison, oral administered PLGA NPs (134 nm) could only reach the brain at a 0.09 % of the initial dose 24 h after administration [14] . Curcumin-loaded PLGA NPs (163 nm) were found to have the lowest brain uptake (approx.…”

“…Several experiments including brain uptake quantification, confocal laser scanning microscopy, behavior studies, thera peutic efficacy of drugs and in vivo toxicity were carried out. The percentage NP uptake was calculated in the brain and expressed as percentage of dose administered per animal, and data was plotted over a 24-h time span [13,14,17,18,21,26,29,30,34,39] . In all cases, the brain weights of rat and mice used to convert % dose/g reported by some authors to % dose were 2 g and 400 mg, respectively [42] .…”

“…Brain uptake of PLGA/PLA NPs (100 -300 nm) were tested at different doses, ranging between 0.02 and 5.25 mg/animal, by quantifying concentration of entrapped drug [13,14,29] or fluorescent marker [17,18,26,30,34,39] after administration to rats [13,14,17,18,30,34] or mice [26,29,39] (Figure 2 ). In all cases, the percentage of dose administered that was transported to the CNS was below 4 % , and the majority of the studies (7 out of 9 reported in this review) showed percentages lower than 1 % .…”

“…0.02 % ) according to quantification of drug level in the brain 1 h after intravenous administration [13] . When the level of entrapped drug was used as a measure to determine brain uptake of NPs, values lower than 0.17 % were reported [13,14] . A study that employed PLA NPs loaded with 3 H-ritonavir, a radioactive labeled drug (300 nm), indicated that a higher percentage (0.6 -1.7 % initial dose) reached the brain 24 h post-administration [29] .…”

“…Among 29 papers cited in this review, 9 papers performed in vitro studies [20,23,24,31,33,37,38,40] , 8 papers focused on in vivo studies [13,15,16,18,21,25,27,30] , and 12 papers did both in vitro and in vivo studies [14,17,19,22,26,28,29,32,34,35,39,41] .…”