Search

RNA interference, a naturally occurring regulatory mechanism in which small interfering RNA (siRNA) molecules are responsible for the sequence-specific suppression of gene expression, emerged as one of the most promising gene therapies in cancer. In this work, we investigate a microfluidics double self-assembly method based on micellization and polyelectrolyte complex formation for the encapsulation of siRNA targeting the BIRC5 gene, a member of the inhibitor of apoptosis gene family, that codes for survivin a protein of theinhibitorof apoptosis protein family that is involved in triple-negative breast cancer (TNBC) proliferation and metastasis within nanoparticles of an amphiphilic chitosan-graft-poly(methyl methacrylate) copolymer and low-molecular weight dermatan sulfate, a polysaccharide targeting the CD44 receptor overexpressed in this tumor. Nanoparticles are spherical and display a hydrodynamic diameter of ∼ 200 nm, as measured by dynamic light scattering and scanning electron microscopy. In addition, these colloidal systems exhibit a strongly negative zeta-potential that confers them excellent physical stability for at least four months owing to electrostatic repulsion and evidences the exposure of the polyanionic dermatan sulfate on the surface. The key role of dermatan sulfate in the active targeting and intracellular delivery of the cargo in the murine breast cancer cell line 4T1, a model of TNBC, is confirmed by confocal laser scanning microscopy and imaging flow cytometry. Finally, the silencing efficiency is demonstrated in 4T1 cell viability, migration, proliferation and spheroid formation assays in vitro. Overall results highlight the promise of this simple, reproducible and scalable method for the nanoencapsulation of siRNA and other therapeutic nucleic acids., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The gold standard drug for colorectal cancer (CRC) treatment, 5-Fluorouracil (5-FU), induces pharmacological tolerance in long-term management. The transcriptional factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) plays a key role in 5-FU resistance. The aim of this work is to study the capability of polyelectrolytes complex nanoparticles of dermatan sulfate (DS) and chitosan (CS), loaded with the anti-inflammatory tripeptide IRW, to sensitize colorectal cancer cells to 5-FU. Fluorescence and flow cytometry studies confirmed the recognition by the nanoformulation, of the cluster of differentiation 44 (CD44) receptor, involved in the initiation and progression of colorectal tumors. Dynamic light scattering (DLS) and flow cytometry reinforced the importance of DS and CD44 receptor in the interaction, as the addition of DS or anti-CD44 antibody blocked the binding. Moreover, the nanoformulation also interacts with 3D colon cancer cultures, namely colonospheres, enriched in cancer stem cells (CSC), subpopulation responsible for drug resistance and metastasis. To evaluate the consequences of this interaction, the subcellular distribution of the transcriptional factor NFκB, is determined by immunofluorescence analysis. Internalization and the intracellular release of IRW inhibited nuclear translocation of NFκB and increased cellular sensitivity to 5-FU. Altogether, the nanoformulation could provide a selective delivery platform for IRW distribution to colorectal tumors, being an innovative strategy toward overcoming 5-FU resistance in CRC therapy., (© 2023 Wiley-VCH GmbH.)

Hypothesis: Modification of polyallylamine hydrochloride (PAH) with heterobifunctional low molecular weight polyethylene glycol (PEG) (600 and 1395 Da), and subsequent attachment of mannose, glucose, or lactose sugars to PEG, can lead to formation of polyamine phosphate nanoparticles (PANs) with lectin binding affinity and narrow size distribution., Experiments: Size, polydispersity, and internal structure of glycosylated PEGylated PANs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and small angle X-ray scattering (SAXS). Fluorescence correlation spectroscopy (FCS) was used to study the association of labelled glycol-PEGylated PANs. The number of polymer chains forming the nanoparticles was determined from the changes in amplitude of the cross-correlation function of the polymers after formation of the nanoparticles. SAXS and fluorescence cross-correlation spectroscopy were used to investigate the interaction of PANs with lectins: concanavalin A with mannose modified PANs, and jacalin with lactose modified ones., Findings: Glyco-PEGylated PANs are highly monodispersed, with diameters of a few tens of nanometers and low charge, and a structure corresponding to spheres with Gaussian chains. FCS shows that the PANs are single chain nanoparticles or formed by two polymer chains. Concanavalin A and jacalin show specific interactions for the glyco-PEGylated PANs with higher affinity than bovine serum albumin., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Hypothesis: Following blood administration, the pristine surface of nanoparticles (NPs) associates with biomolecules from the surrounding environment forming the so-called "biomolecular corona". It is well accepted that the biomolecular corona dramatically affects the NP fate in the biological medium while the pristine surface is no longer available for binding. Recent studies have shown that the glycans associated with the proteins forming the corona have a role in the NP interaction with macrophages, but the glycan identities remain unknown. We aim here to identify the glycan composition of the biomolecular corona and to assess the role of these glycans in the interaction of the proteins from the corona with glycan binding biomolecules, such as lectins., Experiments: In this study, we have characterized the biomolecular corona of citrate stabilised gold NPs after exposure of the NPs to blood plasma at two different plasma concentrations, mimicking the in vitro and in vivo conditions. We have extensively characterized the biomolecular corona using HILIC chromatography and shotgun proteomics. Following this, a lectin binding assay was carried out using Dynamic Light Scattering (DLS) and Fluorescence Correlation Spectroscopy (FCS) to assess whether proteins with known affinity towards specific glycans would bind to the corona., Findings: Our findings highlighted that the protein corona composition is dependent on the exposing conditions. However, under both plasma concentrations, the biantennary sialylated glycans (A2G2S2) are enriched. DLS and FCS confirmed that the glycans are accessible for binding as the corona interacts with lectins with known affinity towards terminal sialic acids and the enzymatic removal of the glycans leads to a decrease in lectin affinity. This study shows for the first time that the glycans are present in the corona and that they could potentially be responsible for the modulation of NP biological processes as they can directly engage with glycan binding receptors that are highly expressed in an organism., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Aim: To develop a new curcumin carrier consisting of murumuru butter nanoparticles (SLN-Cs). Methods: A phase-inversion temperature method was used to produce SLN-Cs. The interaction of SLN-Cs with murine colon adenocarcinoma (CT26) cells in vitro was analyzed by confocal microscopy. Results: Stable SLN-Cs with a high curcumin-loading capacity were obtained. The SLN-Cs were more toxic to CT26 than free curcumin. Fluorescence microscopy images showed the SLN-Cs to be taken up by CT26 cells in vitro . Conclusion: These results indicate that SLN-Cs are suitable carriers of curcumin in aqueous media.

BSA-capped gold nanoclusters are promising theragnostic systems that can be excited to render both fluorescence emission and reactive oxygen species. Although their synthesis and photoluminescence properties are already well described, more accurate information about their use as photosensitizers is required in order to advance towards health applications. In this work, we have obtained BSA-capped gold nanoclusters and characterized their photophysics by different techniques. Singlet oxygen production was detected upon irradiation, which was enough to produce toxicity on two cell lines. Remarkably, an internal energy transfer, probably due to the presence of smaller nanoclusters and the contribution of oxidized residues of BSA in the system, caused fluorescence emission near 640 nm after excitation in the UV range. Additionally, the system was capable of penetrating human skin beyond the stratum corneum, which enhances the potential of these nanoclusters as bifunctional photodynamic therapy effectors and biomarkers with application in a diversity of skin diseases. In the absence of radiation, BSA-capped gold nanoclusters did not cause toxicity in vitro, while their toxic effect on an in vivo model as zebrafish was determined., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this manuscript we review work of our group on the assembly of lipid layers on top of polyelectrolyte multilayers (PEMs). The assembly of lipid layers with zwitterionic and charged lipids on PEMs is studied as a function of lipid and polyelectrolyte composition by the Quartz Crystal Microbalance. Polyelectrolyte lipid interactions are studied by means of Atomic Force Spectroscopy. We also show the coating of lipid layers for engineering different nanomaterials, i.e., carbon nanotubes and poly(lactic-co-glycolic) nanoparticles and how these can be used to decrease in vitro toxicity and to direct the intracellular localization of nanomaterials.

Polyelectrolyte multilayers (PEMs) composed of two natural polysaccharides-chitosan (Chi) and alginate (Alg) were deposited by Layer by layer (LbL) assembly on top of biocompatible poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs). Folic acid (FA) or FA grafted poly(ethylene glycol) (PEG-FA) were covalently bounded to the PEMs via carbodiimide chemistry. The assembly of biocompatible PEMs was monitored on planar surfaces by means of the quartz crystal microbalance with dissipation (QCM-D) technique and on top of PLGA NPs by means of ζ-potential measurements. BSA was used as model protein to characterize protein adsorption on PEMs. QCM-D showed protein deposition could not be observed on the Chi/Alg multilayer, for both Chitosan and Alginate as top layers. Finally, cellular uptake experiments were carried out by co-culture of HepG2 cells in presence of NPs. Flow Cytometry and confocal laser scanning microscopy (CLSM) were used to investigate the influence of the surface chemistry of the NPs on uptake. For the HepG2 cell line significantly less uptake of PLGA NPs coated with Chi/Alg than the bare NPs was observed but the uptake increased after attachment of FA molecules., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Poly[(D,L-lactide)-co-glycolide] nanoparticles coated with polyethyleneimine on their surface were prepared by an emulsification-solvent evaporation method and subsequently surface modified by LBL assembly. The assembly of poly(acrylic acid) and polyethyleneimine on a planar substrate and on the PLGA nanoparticles was monitored by QCM-D, zeta-potential, flow cytometry and TEM. Carboxylic and amino groups in the multilayers were crosslinked by carbodiimide condensation, which was also later used to graft poly(ethylene glycol) (PEG). Rhodamine 6G, 5(6)-carboxyfluorescein and fluorescein were incorporated into the nanoparticles and their release profiles were recorded at 60 degrees C and at 37 degrees C for rhodamine 6G, for nanoparticles with a multilayer coating, and those that were crosslinked and grafted with PEG.

Fusion of lipid-enveloped viruses with endosomal membranes triggered by low pH in the endosome is a key step in the course of viral infection. This ubiquitous mechanism can be used to integrate functional nanoparticles of viral origin into composite materials consisting of a polyelectrolyte multilayer with an adsorbed lipid membrane in a natural and biomimetic way. Polyelectrolyte multilayers as the support for the lipid membrane are a versatile means to combine the biological functions of the viral surface with the multiplicity of polyelectrolyte borne functions into a novel bio/nonbio composite material.

Step-wise adsorption of polyelectrolytes is used for the fabrication of microand nanocapsules with determined size, capsule wall composition and thickness. The capsule walls made of polyelectrolyte multilayers exclude high molecular weight compounds. Assembling of lipid layers onto these polyelectrolyte capsules prevents the permeation of small dyes. Encapsulation of magnetite nanoparticles is demonstrated and the features of these novel capsules are discussed. [ABSTRACT FROM AUTHOR]