Abstract
Oxidative stress and neuroinflammation play a pivotal role in pathomechanisms of brain ischemia. Our research aimed to formulate
a nanotheranostic system for delivering carnosic acid as a neuroprotective agent with anti-oxidative and anti-inflammatory
properties to ischemic brain tissue, mimicked by organotypic hippocampal cultures (OHCs) exposed to oxygen–glucose
deprivation (OGD). In the first part of this study, the nanocarriers were formulated by encapsulating two types of nanocores
(nanoemulsion (AOT) and polymeric (PCL)) containing CA into multilayer shells using the sequential adsorption of charged
nanoobjects method. The newly designed nanoparticles possessed favorable physicochemical characteristics as reflected by
zeta potential and other parameters. Next, we demonstrated that the newly designed gadolinium-containing nanoparticles were
not toxic to OHCs and did not affect the detrimental effects of OGD on the viability of the hippocampal cells. Importantly,
they readily crossed the artificial blood–brain barrier based on the human cerebral microvascular endothelial (hCMEC/D3)
cell line. Furthermore, the PCL-Gd carnosic acid–loaded nanoparticles displayed anti-inflammatory potential, expressed
as decreased OGD-induced HIF-1α and IL-1β levels. Results of the molecular study revealed a complex mechanism of the
nanoformulation on ischemia-related neuroinflammation in OHCs, including anti-inflammatory protein A20 stimulation and
moderate attenuation of the NFκB signaling pathway. Summing up, this study points to acceptable biocompatibility of the
newly designed CA-containing theranostic nanoformulation and emphasizes their interaction with inflammatory processes
commonly associated with the ischemic brain.