Targeted nanoliposomes to improve enzyme replacement therapy of Fabry disease.

The central nervous system represents a major target tissue for therapeutic approach of numerous lysosomal storage disorders. Fabry disease arises from the lack or dysfunction of the lysosomal alpha-galactosidase A (GLA) enzyme, resulting in substrate accumulation and multisystemic clinical manifestations. Current enzyme replacement therapies (ERTs) face limited effectiveness due to poor enzyme biodistribution in target tissues and inability to reach the brain.

Hierarchical Quatsome-RGD Nanoarchitectonic Surfaces for Enhanced Integrin-Mediated Cell Adhesion.

The synthesis and study of the tripeptide Arg-Gly-Asp (RGD), the binding site of different extracellular matrix proteins, e.g., fibronectin and vitronectin, has allowed the production of a wide range of cell adhesive surfaces.

Heterobivalent Ligand for the Adenosine A-Dopamine D Receptor Heteromer.

A G protein-coupled receptor heteromer that fulfills the established criteria for its existence is the complex between adenosine A (AR) and dopamine D (DR) receptors. Here, we have designed and synthesized heterobivalent ligands for the AR-DR heteromer with various spacer lengths. The indispensable simultaneous binding of these ligands to the two different orthosteric sites of the heteromer has been evaluated by radioligand competition-binding assays in the absence and presence of specific peptides that disrupt the formation of the heteromer, label-free dynamic mass redistribution assays in living cells, and molecular dynamic simulations.

Application of Quality by Design to the robust preparation of a liposomal GLA formulation by DELOS-susp method.

Fabry disease is a lysosomal storage disease arising from a deficiency of the enzyme α-galactosidase A (GLA). The enzyme deficiency results in an accumulation of glycolipids, which over time, leads to cardiovascular, cerebrovascular, and renal disease, ultimately leading to death in the fourth or fifth decade of life. Currently, lysosomal storage disorders are treated by enzyme replacement therapy (ERT) through the direct administration of the missing enzyme to the patients.

Impact of Chemical Composition on the Nanostructure and Biological Activity of α-Galactosidase-Loaded Nanovesicles for Fabry Disease Treatment.

Fabry disease is a rare lysosomal storage disorder characterized by a deficiency of α-galactosidase A (GLA), a lysosomal hydrolase. The enzyme replacement therapy administering naked GLA shows several drawbacks including poor biodistribution, limited efficacy, and relatively high immunogenicity in Fabry patients. An attractive strategy to overcome these problems is the use of nanocarriers for encapsulating the enzyme.

Radical Dendrimers Based on Biocompatible Oligoethylene Glycol Dendrimers as Contrast Agents for MRI.

Finding alternatives to gadolinium (Gd)-based contrast agents (CA) with the same or even better paramagnetic properties is crucial to overcome their established toxicity. Herein we describe the synthesis and characterization of entirely organic metal-free paramagnetic macromolecules based on biocompatible oligoethylene glycol dendrimers fully functionalized with 5 and 20 organic radicals (OEG Gn-PROXYL ( = 0, 1) radical dendrimers) with the aim to be used as magnetic resonance imaging (MRI) contrast agents. Conferring high water solubility on such systems is often a concern, especially in large generation dendrimers.

Synthesis of Stable Cholesteryl-Polyethylene Glycol-Peptide Conjugates with Non-Disperse Polyethylene Glycol Lengths.

A method for conjugating cholesterol to peptide ligands through non-disperse polyethylene glycol (ND-PEG) through a non-hydrolysable linkage is described. The iterative addition of tetraethylene glycol macrocyclic sulfate to cholesterol (Chol) renders a family of highly pure well-defined Chol-PEG compounds with different PEG lengths from 4 up to 20 ethylene oxide units, stably linked through an ether bond. The conjugation of these Chol-PEG compounds to the cyclic (RGDfK) peptide though Lys5 side chains generates different lengths of Chol-PEG-RGD conjugates that retain the oligomer purity of the precursors, as analysis by HRMS and NMR has shown.

Engineering a Nanostructured Nucleolin-Binding Peptide for Intracellular Drug Delivery in Triple-Negative Breast Cancer Stem Cells.

Five peptide ligands of four different cell surface receptors (nucleolin, CXCR1, CMKLR1, and CD44v6) have been evaluated as targeting moieties for triple-negative human breast cancers. Among them, the peptide F3, derived from phage display, promotes the fast and efficient internalization of a genetically fused green fluorescent protein (GFP) inside MDA-MB-231 cancer stem cells in a specific receptor-dependent fashion. The further engineering of this protein into the modular construct F3-RK-GFP-H6 and the subsequent construct F3-RK-PE24-H6 resulted in self-assembling polypeptides that organize as discrete and regular nanoparticles.

Carbosilane Dendron-Peptide Nanoconjugates as Antimicrobial Agents.

Over the last decades, multidrug-resistant bacteria have emerged and spread, increasing the number of bacteria, against which commonly used antibiotics are no longer effective. It has become a serious public health problem whose solution requires medical research in order to explore novel effective antimicrobial molecules. On the one hand, antimicrobial peptides (AMPs) are regarded as good alternatives because of their generally broad-spectrum activities, but sometimes they can be easily degraded by the organism or be toxic to animal cells.

Design of a True Bivalent Ligand with Picomolar Binding Affinity for a G Protein-Coupled Receptor Homodimer.

Bivalent ligands have emerged as chemical tools to study G protein-coupled receptor dimers. Using a combination of computational, chemical, and biochemical tools, here we describe the design of bivalent ligand 13 with high affinity ( K = 21 pM) for the dopamine D receptor (DR) homodimer. Bivalent ligand 13 enhances the binding affinity relative to monovalent compound 15 by 37-fold, indicating simultaneous binding at both protomers.

The size matters? A computational tool to design bivalent ligands.

Motivation: Bivalent ligands are increasingly important such as for targeting G protein-coupled receptor (GPCR) dimers or proteolysis targeting chimeras (PROTACs). They contain two pharmacophoric units that simultaneously bind in their corresponding binding sites, connected with a spacer chain. Here, we report a molecular modelling tool that links the pharmacophore units via the shortest pathway along the receptors van der Waals surface and then scores the solutions providing prioritization for the design of new bivalent ligands.

Stimuli-Responsive Functionalization Strategies to Spatially and Temporally Control Surface Properties: Michael vs Diels-Alder Type Additions.

Stimuli-responsive self-assembled monolayers (SAMs) are used to confer switchable physical, chemical, or biological properties to surfaces through the application of external stimuli. To obtain spatially and temporally tunable surfaces, we present microcontact printed SAMs of a hydroquinone molecule that are used as a dynamic interface to immobilize different functional molecules either via Diels-Alder or Michael thiol addition reactions upon the application of a low potential. In spite of the use of such reactions and the potential applicability of the resulting surfaces in different fields ranging from sensing to biomedicine through data storage or cleanup, a direct comparison of the two functionalization strategies on a surface has not yet been performed.

Highly Versatile Polyelectrolyte Complexes for Improving the Enzyme Replacement Therapy of Lysosomal Storage Disorders.

Lysosomal storage disorders are currently treated by enzyme replacement therapy (ERT) through the direct administration of the unprotected recombinant protein to the patients. Herein we present an ionically cross-linked polyelectrolyte complex (PEC) composed of trimethyl chitosan (TMC) and α-galactosidase A (GLA), the defective enzyme in Fabry disease, with the capability of directly targeting endothelial cells by incorporating peptide ligands containing the RGD sequence. We assessed the physicochemical properties, cytotoxicity, and hemocompatibility of RGD-targeted and untargeted PECs, the uptake by endothelial cells and the intracellular activity of PECs in cell culture models of Fabry disease.

α-Galactosidase-A Loaded-Nanoliposomes with Enhanced Enzymatic Activity and Intracellular Penetration.

Lysosomal storage disorders (LSD) are caused by lysosomal dysfunction usually as a consequence of deficiency of a single enzyme required for the metabolism of macromolecules, such as lipids, glycoproteins, and mucopolysaccharides. For instance, the lack of α-galactosidase A (GLA) activity in Fabry disease patients causes the accumulation of glycosphingolipids in the vasculature leading to multiple organ pathology. Enzyme replacement therapy, which is the most common treatment of LSD, exhibits several drawbacks mainly related to the instability and low efficacy of the exogenously administered therapeutic enzyme.

Injectable Hyaluronan Hydrogels with Peptide-Binding Dendrimers Modulate the Controlled Release of BMP-2 and TGF-β1.

BMP-2 and TGF-β1 released from injectable thermoresponsive hydrogels are studied in the presence and absence of branched macromolecules bearing BMP-2 or TGF-β1 affinity binding peptides. The synthesized branched macromolecules and the gelling compositions before and after loading with either BMP-2 or TGF-β1 are characterized physico-chemically and show a significantly lower amount of proteins released in the presence of the affinity binding peptide macromolecules. This study illustrates the potential of affinity binding peptide functionalized dendrimers to modulate the local delivery and availability of growth factors important for musculoskeletal regeneration therapies.

Triazene as a powerful tool for solid-phase derivatization of phenylalanine containing peptides: zygosporamide analogues as a proof of concept.

A novel method for the synthesis of para-substituted phenylalanine containing cyclic peptides is described. The main features of this strategy are the coupling of phenylalanine to the solid support through its side chain via a triazene linkage, on-resin cyclization of the peptide chain, cleavage of the cyclic peptide from the resin under mild acidic conditions and further transformation of the resulting diazonium salt. The usefulness of this approach is exemplified by the solid-phase synthesis of some derivatives of the naturally occurring cyclic depsipeptide zygosporamide.

Multivalent dendrimers presenting spatially controlled clusters of binding epitopes in thermoresponsive hyaluronan hydrogels.

The controlled presentation of biofunctionality is of key importance for hydrogel applications in cell-based regenerative medicine. Here, a versatile approach was demonstrated to present clustered binding epitopes in an injectable, thermoresponsive hydrogel. Well-defined multivalent dendrimers bearing four integrin binding sequences and an azido moiety were covalently grafted to propargylamine-derived hyaluronic acid (Hyal-pa) using copper-catalyzed alkyne-azide cycloaddition (CuAAC), and then combined with pN-modified hyaluronan (Hyal-pN).

Amphiphilic cationic carbosilane-PEG dendrimers: synthesis and applications in gene therapy.

Here we synthesized carbosilane, generation 1 to 3, and PEG-based dendrons functionalized at the periphery with NHBoc groups and at the focal point with azide and alkyne moieties, respectively. The coupling of these two types of dendrons via click chemistry led to the formation of new hybrid dendrimers with two distinct moieties, the hydrophobic carbosilane and the hydrophilic PEG-based dendron. The protected dendrimers were transformed into cationic ammonium dendrimers.

Controlling multivalency and multimodality: up to pentamodal dendritic platforms based on diethylenetriaminepentaacetic acid cores.

A highly versatile synthetic strategy is described to generate multimodal and multivalent platforms based on a diethylenetriaminepentaacetic (DTPA) core. Compounds with different functionalization patterns, from mono- to pentamodal, have been prepared using robust and simple chemistry.

Multifunctional nanovesicle-bioactive conjugates prepared by a one-step scalable method using CO2-expanded solvents.

The integration of therapeutic biomolecules, such as proteins and peptides, in nanovesicles is a widely used strategy to improve their stability and efficacy. However, the translation of these promising nanotherapeutics to clinical tests is still challenged by the complexity involved in the preparation of functional nanovesicles and their reproducibility, scalability, and cost production. Here we introduce a simple one-step methodology based on the use of CO2-expanded solvents to prepare multifunctional nanovesicle-bioactive conjugates.

Biocompatible, multifunctional, and well-defined OEG-based dendritic platforms for biomedical applications.

Given the growing importance of drug and gene delivery systems, imaging agents, biosensors, and theranostics, there is a need to develop new multifunctional and biocompatible platforms. Here we synthesized and fully characterized a family of novel multifunctional and completely monodisperse dendritic platforms. Our synthetic methodology, based on compatible protecting groups and the attachment of monodisperse triethylene glycol units, allows the control of the generation and differentiation of terminal groups, thus giving rise to multifunctional and perfectly-defined products.

Solid-phase synthesis of phenylalanine containing peptides using a traceless triazene linker.

The use of a triazene function to anchor phenylalanine to a polymeric support through its side chain is reported. To prove the usefulness of this strategy in solid-phase peptide synthesis, several bioactive peptides have been prepared including cyclic, C-modified, and protected peptides. The triazene linkage is formed by coupling the diazonium salt of Fmoc-Phe(pNH(2))-OAllyl to a MBHA-polystyrene resin previously functionalized with isonipecotic acid (90%).

Lamellarin D bioconjugates II: Synthesis and cellular internalization of dendrimer and nuclear location signal derivatives.

The design and synthesis of Lamellarin D conjugates with a nuclear localization signal peptide and a poly(ethylene glycol)-based dendrimer are described. Conjugates 1-4 were obtained in 8-84% overall yields from the corresponding protected Lamellarin D. Conjugates 1 and 4 are 1.

McKittrick-Wheelock syndrome treated by laparoscopy: report of 3 cases.

Aim: To present 3 cases of secreting villous adenoma (McKittrick-Wheelock syndrome) successfully treated with laparoscopic surgery.

Cases: We present 3 cases, characterized by chronic diarrhea and requiring hospitalization owing to electrolyte and fluid depletion with acute renal failure. Owing to the extension and location of the adenomas, laparoscopic surgery (low anterior resection or procto-sigmoidectomy resection) was performed after medical treatment and endoscopic diagnosis.

Preparation of ribonuclease S domain-swapped dimers conjugated with DNA and PNA: modulating the activity of ribonucleases.

Obtaining highly specific and active ribonuclease activities is an important goal with numerous medical and biochemical applications. As a step toward more active and specific ribonucleases, we describe the preparation and the enzymatic and structural properties of RNase S monomers and dimers conjugated to DNA and PNA molecules. Poly(dT)n (2'-oligodeoxyribonucleotides, n = 8, 15) and t8 peptide nucleic acid (PNA) chains have been conjugated to the S-peptide of ribonuclease S.