Enabling dual cellular destinations of polymeric nanoparticles for treatment following partial injury to the central nervous system

Abstract

Following neurotrauma, oxidative stress is spread via the astrocytic syncytium and is associated with increased aquaporin 4 (AQP4), inflammatory cell infiltration, loss of neurons and glia and functional deficits. Herein we evaluate multimodal polymeric nanoparticles functionalized with an antibody to an extracellular epitope of AQP4, for targeted delivery of an anti-oxidant as a therapeutic strategy following partial optic nerve transection. Using fluorescence microscopy, spectrophotometry, correlative nanoscale secondary ion mass spectrometry (NanoSIMS) and transmission electron microscopy, in vitro and in vivo, we demonstrate that functionalized nanoparticles are coated with serum proteins such as albumin and enter both macrophages and astrocytes when administered to the site of a partial optic nerve transection in rat. Antibody functionalized nanoparticles synthesized to deliver the antioxidant resveratrol are effective in reducing oxidative damage to DNA, AQP4 immunoreactivity and preserving visual function. Non-functionalized nanoparticles evade macrophages more effectively and are found more diffusely, including in astrocytes, however they do not preserve the optic nerve from oxidative damage or functional loss following injury. Our study highlights the need to comprehensively investigate nanoparticle location, interactions and effects, both in vitro and in vivo, in order to fully understand functional outcomes.

Oligodendroglia Are Particularly Vulnerable to Oxidative Damage after Neurotrauma In Vivo

“…Similarly, intensities of in situ hybridization signal were assessed within ROI defined by NG2 for OPCs and CC1 for mature oligodendrocytes, on a single, central visual slice. The presence of the analyzed transcription factors further confirmed cellular identity within the oligodendroglial lineage (Wang et al, 2001; Fancy et al, Liu et al, 2007;Emery et al, 2009). Subpopulations of cells were analyzed for mRNA expression or the proportion of TUNEL ϩ or caspase3 ϩ cells, based upon whether 8OHdG immunoreactivity in these cells was above or below an arbitrarily defined and constant threshold, or whether they were EdU Ϫ or EdU ϩ .…”

“…At day 28, populations were distinguished based upon whether they were EdU ϩ and therefore newly derived soon after the injury; or EdU Ϫ , and were therefore either derived later than 3 d after injury, or were preexisting at the time of injury. OPC differentiation factors ID2 (Wang et al, 2001;Havrda et al, 2014) and Sox 10 and MYRF (Stolt et al, 2002;Liu et al, 2007) were compared in NG2 ϩ or CC1 ϩ cells that were high or low in 8OHdG immunoreactivity, relying upon oligodendroglial transcription factors to confirm OPC identification. There were no changes in intensity of ID2 ( Fig.…”

Poly(glycidyl methacrylate) coated dual mode upconverting nanoparticles for neuronal cell imaging

“…Most importantly PGMA nanoformulations have been previously demonstrated to deliver drugs (small molecules, peptides, nucleic acids) and cross the blood brain barrier with minimal toxicity. [24][25][26][27][28] This makes the polymer an ideal choice for the development of UC-polymeric drug delivery vehicles for applications in the central nervous system . In the present study, 7.4 ± 1.4 nm NaGdF 4 :Yb,Er nanoparticles were initially synthesised using high-temperature replacement reactions among GdCl 3 , YbCl 3 , ErCl 3 , NH 4 F, and NaOH in the presence of oleic acid (OA).…”

Characterization of polymeric nanoparticles for treatment of partial injury to the central nervous system

“… Before using nanoparticles for therapeutic applications, it is necessary to comprehensively investigate nanoparticle effects, both in vitro and in vivo . In the associated research article [1] we generate multimodal polymeric nanoparticles functionalized with an antibody, that are designed to deliver an anti-oxidant to astrocytes. Here we provide additional data demonstrating the effects of the nanoparticle preparations on an indicator of oxidative stress in an immortalized Müller cell line in vitro .…”

“…NanoSIMS is also used to visualize 40 Ca microdomains in the z dimension of optic nerve that has been subjected to a partial optic nerve transection. The associated article [1] describes the use of NanoSIMS to quantify 40 Ca microdomains in optic nerve from animals treated with various nanoparticle preparations and provides further interpretation and discussion of the findings.…”