RESUMEN
An approach for reducing toxicity and enhancing therapeutic potential of supramolecular polyamine phosphate nanoparticles (PANs) through PEGylation of polyamines before their assembly into nanoparticles is presented here. It is shown that the number of polyethylene glycol (PEG) chains for polyamine largely influence physico-chemical properties of PANs and their biological endpoints. Poly(allylamine hydrochloride) (PAH) are functionalized through carbodiimide chemistry with three ratios of PEG molecules per PAH chain: 0.1, 1, and 10. PEGylated PAH is then assembled into PANs by exposing the polymer to phosphate buffer solution. PANs decrease size and surface charge with increasing PEG ratios as evidenced by dynamic light scattering and zeta potential measurements, with the ten PEG/PAH ratio PANs having practically zero charge. Small angle X-ray scattering (SAXS) proves that PEG chains form a shell around a polyamine core, which is responsible for the screening of positive charges. MTT experiments show that the screening of amine groups decreases nanoparticle toxicity, with the lowest toxicity for the 10 PEG/PAH ratio. Fluorescence correlation spectroscopy (FCS) proves less interaction with proteins for PEGylated PANs. Positron emission tomography (PET) imaging of 18 F labelled PANs shows longer circulation time in healthy mice for PEGylated PANs than non-PEGylated ones.
Asunto(s)
Nanopartículas , Fosfatos , Animales , Ratones , Nanopartículas/toxicidad , Poliaminas/toxicidad , Polietilenglicoles , Dispersión del Ángulo Pequeño , Difracción de Rayos XRESUMEN
Gene editing has emerged as a therapeutic approach to manipulate the genome for killing cancer cells, protecting healthy tissues, and improving immune response to a tumor. The gene editing tool achaete-scute family bHLH transcription factor 1 CRISPR guide RNA (ASCL1-gRNA) is known to restore neuronal lineage potential, promote terminal differentiation, and attenuate tumorigenicity in glioblastoma tumors. Here, we fabricated a polymeric nonviral carrier to encapsulate ASCL1-gRNA by electrostatic interactions and deliver it into glioblastoma cells across a 3D in vitro model of the blood-brain barrier (BBB). To mimic rabies virus (RV) neurotropism, gene-loaded poly (ß-amino ester) nanoparticles are surface functionalized with a peptide derivative of rabies virus glycoprotein (RVG29). The capability of the obtained NPs, hereinafter referred to as RV-like NPs, to travel across the BBB, internalize into glioblastoma cells and deliver ASCL1-gRNA are investigated in a 3D BBB in vitro model through flow cytometry and CLSM microscopy. The formation of nicotinic acetylcholine receptors in the 3D BBB in vitro model is confirmed by immunochemistry. These receptors are known to bind to RVG29. Unlike Lipofectamine that primarily internalizes and transfects endothelial cells, RV-like NPs are capable to travel across the BBB, preferentially internalize glioblastoma cells and deliver ASCL1-gRNA at an efficiency of 10 % causing non-cytotoxic effects.
RESUMEN
Gold nanoparticles (GNPs) are considered promising candidates for healthcare applications, however, their toxicity after long-term exposure to the material remains uncertain. Since the liver is the main filter organ for nanomaterials, this work was aimed at evaluating hepatic accumulation, internalisation and overall safety of well-characterised and endotoxin-free GNPs in healthy mice from 15 minutes to 7 weeks after a single administration. Our data demonstrate that GNPs were rapidly segregated into lysosomes of endothelial cells (LSEC) or Kupffer cells regardless of coating or shape but with different kinetics. Despite the long-lasting accumulation in tissues, the safety of GNPs was confirmed by liver enzymatic levels, as they were rapidly eliminated from the blood circulation and accumulated in the liver without inducing hepatic toxicity. Our results demonstrate that GNPs have a safe and biocompatibile profile despite their long-term accumulation.