Barbara La Ferla

Versatile and Efficient Targeting Using a Single Nanoparticulate Platform: Application to Cancer and Alzheimer's Disease

A versatile and efficient functionalization strategy for polymeric nanoparticles (NPs) has been reported and successfully applied to PEGylated, biodegradable poly(alkyl cyanoacrylate) (PACA) nanocarriers. The relevance of this platform was demonstrated in both the fields of cancer and Alzheimers disease (AD). Prepared by copper-catalyzed azide-alkyne cycloaddition (CuAAC) and subsequent self-assembly in aqueous solution of amphiphilic copolymers, the resulting functionalized polymeric NPs exhibited requisite characteristics for drug delivery purposes: (i) a biodegradable core made of poly(alkyl cyanoacrylate), (ii) a hydrophilic poly(ethylene glycol) (PEG) outer shell leading to colloidal stabilization, (iii) fluorescent properties provided by the covalent linkage of a rhodamine B-based dye to the polymer backbone, and (iv) surface functionalization with biologically active ligands that enabled specific targeting. The construction method is very versatile and was illustrated by the coupling of a small library of ligands (e.g., biotin, curcumin derivatives, and antibody), resulting in high affinity toward (i) murine lung carcinoma (M109) and human breast cancer (MCF7) cell lines, even in a coculture environment with healthy cells and (ii) the β-amyloid peptide 1-42 (Aβ(1-42)), believed to be the most representative and toxic species in AD, both under its monomeric and fibrillar forms. In the case of AD, the ligand-functionalized NPs exhibited higher affinity toward Aβ(1-42) species comparatively to other kinds of colloidal systems and led to significant aggregation inhibition and toxicity rescue of Aβ(1-42) at low molar ratios.

Functionalization of liposomes with ApoE-derived peptides at different density affects cellular uptake and drug transport across a blood-brain barrier model

A promising strategy to enhance blood-brain barrier penetration by drugs is the functionalization of nanocarriers with uptake-facilitating ligands. We studied the cellular uptake, by cultured RBE4 brain capillary endothelial cells, of nanoliposomes (NLs) covalently coupled with monomer or tandem dimer of apolipoprotein E (ApoE)-derived peptides (residues 141-150), at various densities. NLs without functionalization did not show either relevant membrane accumulation or cellular uptake, as monitored by confocal microscopy and quantified by fluorescence-activated cell sorting. Functionalization with peptides mediated an efficient NLs uptake that increased with peptide density; NLs carrying monomeric peptide performed the best. Moreover, we studied the ability of ApoE-NLs to enhance the transport of a drug payload through a RBE4 cell monolayer. The permeability of a tritiated curcumin derivative was enhanced after its entrapment into ApoE-NLs, in particular those functionalized with the dimer (+83% with respect to free drug, P < 0.01). Thus, these NLs appear particularly suitable for implementing further strategies for drug brain targeting.

Effect of curcumin-associated and lipid ligand-functionalized nanoliposomes on aggregation of the Alzheimer's Aβ peptide.

The effect of various types of nanoliposomes (associated with curcumin, phosphatidic acid, cardiolipin, or GM1 ganglioside) on the aggregation of the amyloid-β(1-42) (Aβ(1-42)) peptide was investigated. Nanoliposomes incorporating curcumin (curcumin-liposomes) were prepared by adding curcumin in the lipid phase during liposome preparation, whereas curcumin surface-decorated liposomes were prepared by using a curcumin-lipid conjugate (lipid-S-curcumin liposomes) or by attaching a curcumin derivative on preformed liposomes by click chemistry (click-curcumin liposomes). The lipid ligands (phosphatidic acid, cardiolipin, or GM1) were also incorporated into nanoliposomes during their formation. All nanoliposomes with curcumin, or the curcumin derivative, were able to inhibit the formation of fibrillar and/or oligomeric Aβ in vitro. Of the three forms of curcumin liposomes tested, the click-curcumin type was by far the most effective. Liposomes with lipid ligands only inhibited Aβ fibril and oligomer formation at a very high ratio of liposome to peptide. Curcumin-based liposomes could be further developed as a novel treatment for Alzheimers disease.

Novel Tn Antigen-Containing Neoglycopeptides: Synthesis and Evaluation as Anti Tumor Vaccines

The fully unprotected alpha-C-glycosyl analogue of N-acetylgalactosamine 9 was conjugated by a non-natural oxime bond to the segment peptides (328--340)OVA and (327--339)OVA, affording neoglycopeptides 1--2 and 3, having one or two sugar units, respectively. The three neoglycopeptides were tested in vitro in an antigen presentation assay as antitumor vaccines. Neoglycopeptides 1--3 could be presented to and recognized by the T cell receptor; neoglycopeptide 3, bearing two B-epitopes, was presented to the TCR with higher efficiency, compared to neoglycopeptide 2, having only one B-epitope.

Carbohydrate‐Based Molecular Scaffolding

The use of modified carbohydrates, such as sugar amino acids (SAA), iminosugars and policyclic derivatives, as scaffolds for the generation of bioactive compounds, and the use of carbohydrates as building blocks or ligands for the production of polymers for biomedical applications, is reviewed.The use of modified carbohydrates, such as sugar amino acids (SAA), iminosugars and policyclic derivatives, as scaffolds for the generation of bioactive compounds, and the use of carbohydrates as building blocks or ligands for the production of polymers for biomedical applications, is reviewed.

Lipases as Useful Tools for the Stereo- and Regioselective Protection and Deprotection of Carbohydrates

Summary. Stereo- and regioselective acylation and deacylation of carbohydrates can be achieved using lipases as biocatalysts. These enzymes are extremely versatile, quite stable in aqueous and organic solvents, easily available, and easy to handle. Recently, they have become the object of site directed mutagenesis which suggests that they soon could be ‘built ad hoc’ for specific necessities.

Curcumin derivatives as new ligands of Aβ peptides

Curcumin derivatives with high chemical stability, improved solubility and carrying a functionalized appendage for the linkage to other entities, have been synthesized in a straightforward manner. All compounds retained Curcumin ability to bind Aβ peptide oligomers without inducing their aggregation. Moreover all Curcumin derivatives were able to stain very efficiently Aβ deposits.

Carbohydrate mimetics and scaffolds: sweet spots in medicinal chemistry

Several glycoprocessing enzymes and glycoreceptors have been recognized as important targets for therapeutic intervention. This concept has inspired the development of important classes of therapeutics, such as anti-influenza drugs inhibiting influenza virus neuraminidase, anti-inflammatory drugs targeting lectin-sialyl-Lewis X interaction and glycosidase inhibitors against HIV, Gauchers disease, hepatitis and cancer. These therapeutics are mainly carbohydrate mimics in which proper modifications permit stronger interactions with the target protein, higher stability, better pharmacokinetic properties and easier synthesis. Furthermore, the conformational rigidity and polyfunctionality of carbohydrates stimulate their use as scaffolds for the generation of libraries by combinatorial decoration with different pharmacophores. This mini-review will present examples of how to exploit carbohydrates mimics and scaffolds in drug research.

Synthesis of disaccharidic sub-units of a new series of heparin related oligosaccharides

The chemical synthesis of disaccharides1 and2, useful building-blocks for the preparation of a new series of heparin related oligosaccharides containing the unusual sequence (GlcN-IdoA)n, is described. In addition, the orthogonality of the protective groups would allow access to a wide array of differently sulfated oligosaccharides. As the simplest members of this new class of oligomer, the synthesis of sulfated disaccharides3 and4 fully deprotected is reported. Compounds1 and2 have been synthesised as building blocks for a new family of heparin related oligosaccharides containing the unusual sequence (GlcN-IdoA)n. In addition, the orthogonality of the protective groups would allow access to a wide array of differently sulfated oligosaccharides. Download full-size image

cis-Glyco-fused benzopyran compounds as new amyloid-β peptide ligands

A small library of glyco-fused benzopyran compounds has been synthesised. Their interaction features with Aβ peptides have been characterised by using STD-NMR and trNOESY experiments. The conformational analysis of the compounds has also been carried out through molecular mechanics (MM) and molecular dynamics (MD) simulations.