The aggregation of amyloid-β peptide (Aβ) has been linked to the formation of neuritic plaques, which are pathological hallmarks of Alzheimer's disease (AD). Various natural compounds have been ...suggested as therapeutics for AD. Among these compounds, resveratrol has aroused great interest due to its neuroprotective characteristics. Here, we provide evidence that grape skin and grape seed extracts increase the inhibition effect on Aβ aggregation. However, after intravenous injection, resveratrol is rapidly metabolized into both glucuronic acid and sulfate conjugations of the phenolic groups in the liver and intestinal epithelial cells (within less than 2 h), which are then eliminated. In the present study, we show that solid lipid nanoparticles (SLNs) functionalized with an antibody, the anti-transferrin receptor monoclonal antibody (OX26 mAb), can work as a possible carrier to transport the extract to target the brain. Experiments on human brain-like endothelial cells show that the cellular uptake of the OX26 SLNs is substantially more efficient than that of normal SLNs and SLNs functionalized with an unspecific antibody. As a consequence, the transcytosis ability of these different SLNs is higher when functionalized with OX-26.
In the present paper, we report results from a study of the structure and physicochemical properties of gold nanoparticles modified with poly(ethylene glycol) (PEG) designed for the drug delivery of ...the proteasome inhibitor Bortezomib (BTZ) in cancer therapy. A number of advanced analytical techniques were used to define important physicochemical characteristics such as composition, structure, surface properties, particle size and morphology. A new approach based on detailed NMR studies was employed to define specific intermolecular interactions and mechanisms of drug immobilization and location into surface modified gold nanoparticles (AuNPs). Particularly important information was gained from analysis of NMR spectroscopic parameters such as the spectral line shape, translation diffusion, the nuclear Overhauser effect (NOE) and spin-lattice relaxation (T1). The results confirmed the coexistence of two different types of BTZ inclusion into polyethylene glycol coated gold nanoparticles: (i) association with the polymer chains by weak H-bonds and/or dipole-charge interactions and (ii) adsorption on the surface of the gold nanoparticles. The results allowed for determination of the overall structure of Bortezomib loaded PEG coated AuNPs, which is related to the therapeutic drug efficacy and activity in the treatment of cancer.
Colloidal gold nanoparticles are targeting probes to improve varlitinib delivery into cancer cells. The nanoconjugates were designed by the bioconjugation of pegylated gold nanoparticles with ...varlitinib via carbodiimide-mediated cross-linking and characterized by infrared and X-ray photoelectron spectroscopy. The drug release response shows an initial delay and a complete drug release after 72 h is detected. In vitro experiments with MIA PaCa-2 cells corroborate that PEGAuNPsVarl conjugates increase the varlitinib toxic effect at very low concentrations (IC50 = 80 nM) if compared with varlitinib alone (IC50 = 259 nM). Our results acknowledge a decrease of drug side effects in normal cells and an enhancement of drug efficacy against to the pancreatic cancer cells reported.
Glioblastoma multiforme (GBM) is the most common and lethal type of brain tumor, and the clinically available approaches for its treatment are not curative. Despite the intensive research, biological ...barriers such as the blood-brain barrier (BBB) and tumor cell membranes are major obstacles to developing novel effective therapies. Nanoparticles (NPs) have been explored as drug delivery systems (DDS) to improve GBM therapeutic strategies. NPs can circumvent many of the biological barriers posed by this devastating disease, enhancing drug accumulation in the target site. This can be achieved by employing strategies to target the transferrin receptor (TfR), which is heavily distributed in BBB and GBM cells. These targeting strategies comprise the modification of NPs' surface with various molecules, such as transferrin (Tf), antibodies, and targeting peptides. This review provides an overview and discussion on the recent advances concerning the strategies to target the TfR in the treatment of GBM, as their benefits and limitations.
Liposomes modified with anti-amyloid (19B8) and anti-transferrin receptor (OX26) monoclonal antibodies through the coupling reagents maleimide and biotin-streptavidin system.
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...•Immunoliposomes for peptide delivery to brain areas affected by amyloid are proposed.•The cellular uptake depends on the cross linker used for liposome surface decoration.•Bulky ligands between the liposome surface and antibody are more efficient.•In vivo assays show an enhanced concentration of the targeted carriers in rat brains.
Drug delivery systems that can reach brain areas affected by amyloid deposits are still underdeveloped. We propose pegylated liposomes functionalized with two antibodies, the anti-transferrin receptor monoclonal antibody (OX26MAb) and the anti-amyloid beta peptide antibody (19B8MAb), as nanocarriers of drugs for Alzheimer’s disease therapy. Two distinct conjugation methods are investigated. In one formulation, the OX26MAb is conjugated to the tip of polyethylene glycol molecules through the maleimide group and the 19B8MAb is bound through the streptavidin–biotin complex. In the second system the conjugation reagents are swapped between the antibodies. Fluorescence spectroscopy experiments on porcine brain capillary endothelial cells show that the cellular uptake of the immunoliposomes is substantially more efficient if OX26MAb antibody is conjugated through the streptavidin–biotin complex instead of the maleimide group. The ability of the immunoliposomes to cross the blood brain barrier was established by in vivo studies in wild type rats. Our results demonstrate the importance of the conjugation method used to bind the antibody that targets the blood brain barrier to immunoliposomes for efficient drug delivery to the brain.
The aim of this study was to develop drug delivery nanosystems based on pegylated gold nanoparticles (PEGAuNPs) for a combination against pancreatic cancer cells. Doxorubicin and varlitinib, an ...anthracycline and a tyrosine kinase inhibitor respectively, were conjugated with gold nanoparticles. The systems were characterized, after synthesis, regarding their size, stability and morphology. An efficient conjugation of doxorubicin and varlitinib with PEGAuNPs was revealed. The cytotoxicity effect induced by the combination of the nanoconjugates was investigated in pancreatic cancer cell lines. Doxorubicin and varlitinib conjugated with PEGAuNPs revealed a combined effect to decrease the cell survival of the cancer line S2-013s, while reducing the drugs' toxicity for the healthy pancreatic cells hTERT-HPNE. This study highlights the promising potential of PEGAuNPs for targeted delivery of therapeutic drugs into human cells, enhancing the antitumor growth-inhibition effect on cancer cells, and decreasing the toxicity against normal cells. In cancer therapy, the present approach based on PEGAuNP functionalization can be further explored to increase drug targeting efficiency and to reduce side effects.
Development of therapeutics for brain disorders is one of the more difficult challenges to be overcome by the scientific community due to the inability of most molecules to cross the blood-brain ...barrier (BBB). Antibody-conjugated nanoparticles are drug carriers that can be used to target encapsulated drugs to the brain endothelial cells and have proven to be very promising. They significantly improve the accumulation of the drug in pathological sites and decrease the undesirable side effect of drugs in healthy tissues. We review the systems that have demonstrated promising results in crossing the BBB through receptor-mediated endocytic mechanisms for the treatment of neurodegenerative disorders such as Alzheimer's and Parkinson's disease.
A drug delivery system based on colloidal pegylated gold nanoparticles (PEGAuNPs) conjugated with the tyrosine kinase inhibitor afatinib was designed and tested for enhancing the drug activity ...against pancreatic and NSCLC cells.
PEGAuNPs were synthesized and characterized physicochemically. Confocal imaging was performed to evaluate the nanoparticle (NP) internalization in cancer cells. For cell-cycle distribution analysis, conjugated NPs and afatinib alone were incubated with cells and alterations on the cell-cycle profile subsequently analyzed by total DNA staining. Cancer cell survival and growth inhibition following incubation with afatinib and PEGAuNPs-afatinib (concentrations between 0.007 and 0.500 µM afatinib) were evaluated.
A higher cellular uptake of PEGAuNPs was observed by cancer cells. Our data suggest an efficient conjugation of PEGAuNPs with the drug, enhancing the afatinib activity in comparison with afatinib alone. In fact, IC50 and GI50 results obtained show that the PEGAuNPs-afatinib conjugate is ca. 5 and 20 times more potent than afatinib alone in S2-013 and A549 cell lines, respectively.
Conjugating PEGAuNPs with afatinib is a promising antitumor delivery system for cancer therapy as it improves drug efficacy, allowing a reduction in drug dose used and minimizing possible toxicity-related side effects.
Gold nanoparticles (AuNPs) are inorganic and biocompatible nanovehicles capable of conjugating biomolecules to enhance their efficacy in cancer treatment. The high and reactive surface area provides ...good advantages for conjugating active compounds. Two approaches were developed in this work to improve the Epigallocatechin-3-gallate (EGCG) antioxidant efficacy. AuNPs were synthesized by reducing gold salt with chitosan. One other nanosystem was developed by functionalizing AuNPs with cysteamine using the Turkevitch method. The physico-chemical characterization of EGCG conjugated in the two nanosystems-based gold nanoparticles was achieved. The in vitro toxic effect induced by the nanoconjugates was evaluated in pancreatic cancer cells, showing that encapsulated EGCG keeps its antioxidant activity and decreasing the BxPC3 cell growth. A significant cell growth inhibition was observed in 50% with EGCG concentrations in the range of 2.2 and 3.7 μM in EGCG-ChAuNPs and EGCG-Cyst-AuNPs nanoconjugates, respectively. The EGCG alone had to be present at 23 μM to induce the same cytotoxicity response. Caspase-3 activity assay demonstrated that the conjugation of EGCG induces an enhancement of BxPC3 apoptosis compared with EGCG alone. In conclusion, AuNPs complexes can be used as delivery carriers to increase EGCG antioxidant activity in cancer tissues.
Nanostructure of polysaccharide complexes Coelho, Sílvia; Moreno-Flores, Susana; Toca-Herrera, José L. ...
Journal of colloid and interface science,
11/2011, Letnik:
363, Številka:
2
Journal Article
Recenzirano
Nanoparticles made of gum arabic and chitosan (degree of acetylation 5) at weight ratio of 1 (scale bar=200nm). Display omitted
► Gum arabic–chitosan nanostructures. ► Chitosan degree of acetylation ...(DA) determines the structure of the complexes. ► Gum arabic and chitosan with high charge density (DA 5%) form nanoparticles of 200nm. ► Using chitosan with higher DA (25%), soluble complexes are obtained. ► Soluble complexes are flat when adsorbed on mica surfaces (height⩽10nm).
The interaction of gum arabic (GA) with chitosan (Ch) of different degree of deacetylation was studied by turbidity measurements, dynamic light scattering and atomic force microscopy. The structure of the complexes was found to be directly related to the charge density of chitosan molecules. Gum arabic and chitosan with a degree of deacetylation of 75% form soluble complexes with a loosely globular structure of about 250nm, at weight ratios up to 1.2, if the concentrations are kept low (total biopolymer concentration up to 0.06%). If chitosan has a higher charge density (degree of deacetylation of 93%), colloidal particles are formed, independently of the polymer concentration or ratio. At low concentrations and GA/Ch ratios of 1 or 1.2, the particles have diameters of 200–250nm. The formation of soluble complexes is attributed to a chitosan lower charge density and the presence of non-charged monomers, which prevent the efficient self-assembly of the macromolecules.
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