Dendritic beta-cyclodextrin (betaCD) derivatives bearing multivalent mannosyl ligands have been prepared and assessed for their binding efficiency toward the tetrameric plant lectin concanavalin A (Con A) and a mammalian mannose/fucose specific cell surface receptor from macrophages. The synthetic strategy exploits the reactivity between isothiocyanate and amine functionalities for the high-yielding assembly via thioureido links of the various building blocks, including host, spacer, branching, and carbohydrate ligand elements. The methodology has been applied to the preparation of a series of betaCD-polymannoside scaffolds differing in the ligand valency and geometry. This series allowed us to explore: (i) The effects of the glycodendritic architecture on the binding efficiency; (ii) the mutual influence between the cyclodextrin core and the glycodendritic moieties on the molecular inclusion and lectin-binding properties; and (iii) the consequence of inclusion complex formation, using the anticancer drug docetaxel (Taxotère) as a target guest, on biological recognition. Our results confirm the high drug solubilization capability of this new type of betaCD-dendrimer construct and indicate that subtle changes in the architecture of the conjugate may have important consequences on receptor affinity. Interestingly, the host-guest interaction can be monitored to build up supramolecular dynamic glycoclusters with increased lectin affinity. Alternatively, the information obtained from the structure-lectin-binding avidity-inclusion capability studies has been put forward in the design of very efficient molecular transporters for docetaxel based on glycodendritic CD dimers.

Self-assembled cyclodextrin (CD)-DNA nanoparticles (CDplexes) exhibiting transfection efficiencies significantly higher than PEI-based polyplexes have been prepared from homogeneous seven-fold symmetric polyaminothiourea amphiphiles constructed on a beta-cyclodextrin scaffold.

A molecular-diversity-oriented approach for the preparation of well-defined polycationic amphiphilic cyclodextrins (paCDs) as gene-delivery systems is reported. The synthetic strategy takes advantage of the differential reactivity of primary versus secondary hydroxyl groups on the CD torus to regioselectively decorate each rim with cationic elements and lipophilic tails, respectively. Both the charge density and the hydrophobic-hydrophilic balance can be finely tuned in a highly symmetrical architecture that is reminiscent of both cationic lipids and cationic polymers, the two most prominent types of nonviral gene vectors. The monodisperse nature of paCDs and the modularity of the synthetic scheme are particularly well suited for structure-activity relationship studies. Gel electrophoresis revealed that paCDs self-assemble in the presence of plasmid DNA (pDNA) to provide homogeneous, stable nanoparticles (CDplexes) of 70-150 nm that fully protect pDNA from the environment. The transfection efficiency of the resulting CDplexes has been investigated in vitro on BNL-CL2 and COS-7 cell lines in the absence and presence of serum and found to be intimately dependent on architectural features. Facial amphiphilicity and the presence of a cluster of cationic and hydrogen-bonding centers for cooperative and reversible complexation of the polyanionic DNA chain is crucial to attain high transgene expression levels with very low toxicity profiles. Further enhancement of gene expression, eventually overcoming that of polyplexes from commercial polyethyleneimine (PEI) polymers (22 kDa), is achieved by building up space-oriented dendritic polycationic constructs.

A series of β-cyclodextrin (βCD)-scaffolded glycoclusters exposing heterogeneous yet perfectly controlled displays of α-mannosyl (α-Man) and β-lactosyl (β-Lact) antennas were synthesized to probe the mutual influence of varying densities of the saccharide motifs in the binding properties toward different plant lectins. Enzyme-linked lectin assay (ELLA) data indicated that the presence of β-Lact residues reinforced binding of α-Man to the mannose-specific lectin concanavalin A (Con A) even though homogeneous β-Lact clusters are not recognized at all by this lectin, supporting the existence of synergic recognition mechanisms (heterocluster effect). Conversely, the presence of α-Man motifs in the heteroglycoclusters also resulted in a binding-enhancing effect of β-Lact toward peanut agglutinin (PNA), a lectin strongly binding multivalent lactosides but having no detectable affinity for α-mannopyranosides, for certain architectural arrangements. Two-site, sandwich-type ELLA data corroborated the higher lectin clustering efficiency of heterogeneous glycoclusters compared with homogeneous displays of the putative sugar ligand with identical valency. A turbidity assay was also consistent with the previous observations. Most revealingly, the lectin cross-linking ability of heterogeneous glycoclusters was sensitive to the presence of high concentrations of the non-ligand sugar, strongly suggesting that "mismatching" saccharide motifs may modulate carbohydrate-lectin specific recognition in a lectin-dependent manner when present in highly dense displays together with the "matching" ligand, a situation frequently encountered in biological systems.

Background: Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have tremendous promise for application in cardiac regeneration, but their translational potential is limited by an immature phenotype. We hypothesized that large-scale manufacturing of mature hPSC-CMs could be achieved via culture on polydimethylsiloxane (PDMS) lined roller bottles and that the transplantation of these cells would mediate better structural and functional outcomes than with conventional immature hPSC-CM populations. Methods: We comprehensively phenotyped hPSC-CMs after in vitro maturation for 20 and 40 days on either PDMS or standard tissue culture plastic (TCP) substrates. All hPSC-CMs were generated using a transgenic hPSC line that stably expressed a voltage-sensitive fluorescent reporter to facilitate in vitro and in vivo electrophysiological studies, and cardiomyocyte populations were also analyzed in vitro by immunocytochemistry, ultrastructure and fluorescent calcium imaging, as well as bulk and single-cell transcriptomics. We next compared outcomes after the transplantation of these populations into a guinea pig model of myocardial infarction (MI) using endpoints including histology, optical mapping of graft- and host-derived action potentials, echocardiography, and telemetric electrocardiographic (ECG) monitoring. Results: We demonstrated the economic generation of >1x10 8 mature hPSC-CMs per PDMS-lined roller bottle. Compared to their counterparts generated on TCP substrates, PDMS-matured hPSC-CMs exhibited increased cardiac gene expression and more mature structural and functional properties in vitro. More importantly, intra-cardiac grafts formed with PDMS-matured myocytes showed greatly enhanced structure and alignment, better host-graft electromechanical integration, less pro-arrhythmic behavior, and greater beneficial effects on contractile function. Conclusions: In summary, we describe practical methods for the scaled generation of mature hPSC-CMs and provide the first evidence that the transplantation of more mature cardiomyocytes yields better outcomes in vivo.