Design and characterization of Zweimab and Doppelmab, high affinity dual antagonistic anti-TSLP/IL13 bispecific antibodies.

Patients with severe Th2 type asthma often have a steroid resistant phenotype and are prone to acute exacerbations. Current novel therapies have only marginal therapeutic effects. One of the hypotheses for lack of major efficacy in most patients is targeting only one redundant pathway leaving others active. Hence, we have designed and developed novel highly potent bispecific anti-TSLP/IL13 antibodies called Zweimabs (monovalent bispecific) and Doppelmabs (bivalent bispecific) that concurrently inhibits the signaling by these two cytokines.

Sticky Patches on Lipid Nanoparticles Enable the Selective Targeting and Killing of Untargetable Cancer Cells.

Effective targeting by uniformly functionalized nanoparticles is limited to cancer cells expressing at least two copies of targeted receptors per nanoparticle footprint (approximately ≥2 × 10(5) receptor copies per cell); such a receptor density supports the required multivalent interaction between the neighboring receptors and the ligands from a single nanoparticle. To enable selective targeting below this receptor density, ligands on the surface of lipid vesicles were displayed in clusters that were designed to form at the acidic pH of the tumor interstitium. Vesicles with clustered HER2-targeting peptides within such sticky patches (sticky vesicles) were compared to uniformly functionalized vesicles. On HER2-negative breast cancer cells MDA-MB-231 and MCF7 {expressing (8.3 ± 0.8) × 10(4) and (5.4 ± 0.9) × 10(4) HER2 copies per cell, respectively}, only the sticky vesicles exhibited detectable specific targeting (KD ≈ 49-69 nM); dissociation (0.005-0.009 min(-1)) and endocytosis rates (0.024-0.026 min(-1)) were independent of HER2 expression for these cells. MDA-MB-231 and MCF7 were killed only by sticky vesicles encapsulating doxorubicin (32-40% viability) or α-particle emitter (225)Ac (39-58% viability) and were not affected by uniformly functionalized vesicles (>80% viability). Toxicities on cardiomyocytes and normal breast cells (expressing HER2 at considerably lower but not insignificant levels) were not observed, suggesting the potential of tunable clustered ligand display for the selective killing of cancer cells with low receptor densities.

Masking and triggered unmasking of targeting ligands on liposomal chemotherapy selectively suppress tumor growth in vivo.

We investigated the feasibility and efficacy of a drug delivery strategy to vascularized cancer that combines targeting selectivity with high uptake by targeted cells and high bioexposure of cells to delivered chemotherapeutics. Targeted lipid vesicles composed of pH responsive membranes were designed to reversibly form phase-separated lipid domains, which are utilized to tune the vesicle's apparent functionality and permeability. During circulation, vesicles mask functional ligands and stably retain their contents. Upon extravasation in the tumor interstitium, ligand-labeled lipids become unmasked and segregated within lipid domains triggering targeting to cancer cells followed by internalization. In the acidic endosome, vesicles burst release the encapsulated therapeutics through leaky boundaries around the phase-separated lipid domains. The pH tunable vesicles contain doxorubicin and are labeled with an anti-HER2 peptide. In vitro, anti-HER2 pH tunable vesicles release doxorubicin in a pH dependent manner, and exhibit 233% increase in binding to HER2-overexpressing BT474 breast cancer cells with lowering pH from 7.4 to 6.5 followed by significant (50%) internalization. In subcutaneous BT474 xenografts in nude mice, targeted pH tunable vesicles decrease tumor volumes by 159% relative to nontargeted vesicles, and they also exhibit better tumor control by 11% relative to targeted vesicles without an unmasking property. These results suggest the potential of pH tunable vesicles to ultimately control tumor growth at relatively lower administered doses.

Solid-phase synthesis of short α-helices stabilized by the hydrogen bond surrogate approach.

Stabilized α-helices and nonpeptidic helix mimetics have emerged as powerful molecular scaffolds for the discovery of protein-protein interaction inhibitors. Protein-protein interactions often involve large contact areas, which are often difficult for small molecules to target with high specificity. The hypothesis behind the design of stabilized helices and helix mimetics is that these medium-sized molecules may pursue their targets with higher specificity because of a larger number of contacts. This protocol describes an optimized synthetic strategy for the preparation of stabilized α-helices that feature a carbon-carbon linkage in place of the characteristic N-terminal main-chain hydrogen bond of canonical helices. Formation of the carbon-carbon bond is enabled by a microwave-assisted ring-closing metathesis reaction between two terminal olefins on the peptide chain. The outlined strategy allows the synthesis and purification of a hydrogen bond surrogate (HBS) α-helix in ∼ 1 week.

Morphology controlled growth of chitosan-bound microtubes and a study of their biocompatibility and antibacterial activity.

Self-assembled peptide microtubes are fabricated with the biopolymer chitosan. The microtubes are covalently attached to chitosan and the morphology of the chitosan assembled on the surface of the microtubes can be tuned by altering the pH of the growth solution. Cytotoxicity studies in the presence of mouse embryonic fibroblasts indicate that the chitosan-bound microtubes are highly biocompatible and the cells are able to survive and proliferate at a similar rate to the control. Antibacterial studies in the presence of E. coli prove that the chitosan-bound microtubes are bactericidal. This simple method for the development of biocompatible microstructures will facilitate cell targeting, fabrication of efficient carrier devices, and the preparation of highly efficient antibacterial materials.