Combined Dopamine and Grape Seed Extract-Loaded Solid Lipid Nanoparticles: Nasal Mucosa Permeation, and Uptake by Olfactory Ensheathing Cells and Neuronal SH-SY5Y Cells

Abstract

We have already formulated solid lipid nanoparticles (SLNs) in which the combination of the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) was supposed to be favorable for Parkinson’s disease (PD) treatment. In fact, GSE supply would reduce the PD-related oxidative stress in a synergic effect with DA. Herein, two different methods of DA/GSE loading were studied, namely, coadministration in the aqueous phase of DA and GSE, and the other approach consisting of a physical adsorption of GSE onto preformed DA containing SLNs. Mean diameter of DA coencapsulating GSE SLNs was 187 ± 4 nm vs. 287 ± 15 nm of GSE adsorbing DA-SLNs. TEM microphotographs evidenced low-contrast spheroidal particles, irrespective of the SLN type. Moreover, Franz diffusion cell experiments confirmed the permeation of DA from both SLNs through the porcine nasal mucosa. Furthermore, fluorescent SLNs also underwent cell-uptake studies by using flow cytometry in olfactory ensheathing cells and neuronal SH-SY5Y cells, evidencing higher uptake when GSE was coencapsulated rather than adsorbed onto the particles.

Solid Lipid Nanoparticles Containing Dopamine and Grape Seed Extract: Freeze-Drying with Cryoprotection as a Formulation Strategy to Achieve Nasal Powders

“…Indeed, it can be observed that, only for DA-co-GSE-SLNs-Me-β-CD and GSE-ads-DA-SLNs-sucrose systems, a C1s deconvolution was typical of the carbohydrate-based systems, thus evidencing a surface presence of sucrose (or Me-β-CD). In all the other systems, C1s curve-fitting was typical of plain SLNs (whose curve-fitting has already been reported by us [12]), thus evidencing a negligible presence of the cryoprotectant on the surface. Similar C1s curve-fittings were observed for the non-cryoprotected systems reported in Figure S1 (see Supplementary Data).…”

“…Throughout the manuscript, the resulting SLNs were abbreviated "DA-co-GSE-SLNs". For GSE-adsorbing DA SLNs, DAloaded SLNs were first formulated as reported elsewhere [10,12] but starting from 20 mg of DA rather than 10 mg to force neurotransmitter initial cargo. After cooling the particles down at room temperature, an aliquot of 0.5 mL of the resulting DA-SLNs was incubated with 1 mL of GSE aqueous solution (1 mg/mL concentration) at room temperature for 3 h under light protection and maintaining mild stirring (50 oscillations/min).…”

“…In this regard, we have demonstrated that Gelucire ® 50/13, a self-emulsifying lipid, as a component of SLNs, is capable of increasing the drug-loading of hydrophilic active principles [9,10] such as the neurotransmitter dopamine (DA), whose concentration is diminished in the Parkinsonian patient's brain. Therefore, we have prepared DA-loaded Gelucire ® 50/13 SLNs (DA-SLNs) [11] and, then, DA-SLN adsorbing grape seed extract (GSE) SLNs (i.e., GSE/DA-SLNs) by the melt homogenization method [11] and, then, DA-SLN adsorbing grape seed extract (GSE) SLNs (i.e., GSE/DA-SLNs) [12]. These last nanocarriers represent "multifunctional nanomedicines" that combine multiple biological functions into a single nanosystem with the capacity to achieve enhanced therapeutic responses, and the usefulness of this approach in brain diseases has been recently pointed out [13].…”

Dopamine- and Grape-Seed-Extract-Loaded Solid Lipid Nanoparticles: Interaction Studies between Particles and Differentiated SH-SY5Y Neuronal Cell Model of Parkinson’s Disease

“…In this study, we focused on the in vitro effects of DA/GSE-SLN administration by exploiting the advantage of differentiated SH-SY5Y cells both as promising models for developing therapies for PD and for testing SLNs [38][39][40]; the same study was previously conducted on undifferentiated SH-SY5Y cells [32]. The SLNs tested here are highly performing transport systems exploited by the pharmaceutical research for their ability to efficiently cross the BBB when the particle size is in the range of 200-500 nm, so they have an increased blood circulation time and the drug is in contact with the BBB for the maximum time.…”

“…In the context of a project aiming at brain delivery of new lipid nanocarriers by intranasal administration, we prepared two different types of in vitro formulations of SLNs combining the neurotransmitter DA and the natural antioxidant mixture Grape Seed Extract (GSE). We formulated SLNs in which both active principles were co-loaded with SLNs in which GSE was physically adsorbed onto preformed DA-SLNs [31,32], according to the working hypothesis that an antioxidant-based therapy might reduce ROS connected to PD along with providing a synergistic effect with the exogenous DA supply. Indeed, rather than exploiting the antioxidant effects arising from vitamin E [33,34], we selected polyphenols from GSE, mainly consisting of proanthocyanidins, to assess both their potential therapeutic and antioxidant effects.…”