Glucagon Like Peptide 1 Receptor Agonists for Targeted Delivery of Antisense Oligonucleotides to Pancreatic Beta Cell.

The extra hepatic delivery of antisense oligonucleotides (ASOs) remains a challenge and hampers the widespread application of this powerful class of therapeutic agents. In that regard, pancreatic beta cells are a particularly attractive but challenging cell type because of their pivotal role in diabetes and the fact that they are refractory to uptake of unconjugated ASOs. To circumvent this, we have expanded our understanding of the structure activity relationship of ASOs conjugated to Glucagon Like Peptide 1 Receptor (GLP1R) agonist peptide ligands. We demonstrate the key role of the linker chemistry and its optimization to design maleimide based conjugates with improved in vivo efficacy. In addition, truncation studies and scoping of a diverse set of GLP1R agonists proved fruitful to identify additional targeting ligands efficacious in vivo including native hGLP1(7-36)NH2. Variation of the carrier peptide also shed some light on the dramatic impact of subtle sequence differences on the corresponding ASO conjugate performance in vivo, an area which clearly warrant further investigations. We have confirmed the remarkable potential of GLP1R agonist conjugation for the delivery of ASOs to pancreatic beta cell by effectively knocking down islet amyloid polypeptide (IAPP) mRNA, a potential proapoptotic target, in mice.

Peptides as a platform for targeted therapeutics for cancer: peptide-drug conjugates (PDCs).

Peptides can offer the versatility needed for a successful oncology drug discovery approach. Peptide-drug conjugates (PDCs) are an emerging targeted therapeutic that present increased tumour penetration and selectivity. Despite these advantages, there are still limitations for the use of peptides as therapeutics exemplified through their slow progression to get into the clinic and limited oral bioavailability. New approaches to address these problems have been studied and successfully implemented to enhance the stability of peptides and their constructs. There is great promise for the future of PDCs with two molecules already on the market and many variations currently undergoing clinical trials, such as bicycle-toxin conjugates and peptide-dendrimer conjugates. This review summarises the entire process needed for the design and successful development of an oncology PDC including chemical and nanomaterial strategies to enhance peptide stability within circulation, the function of each component of a PDC construct, and current examples in clinical trials.

Identification of novel GPR81 agonist lead series for target biology evaluation.

GPR81 is a novel drug target that is implicated in the control of glucose and lipid metabolism. The lack of potent GPR81 modulators suitable for in vivo studies has limited the pharmacological characterization of this lactate sensing receptor. We performed a high throughput screen (HTS) and identified a GPR81 agonist chemical series containing a central acyl urea scaffold linker. During SAR exploration two additional new series were evolved, one containing cyclic acyl urea bioisosteres and another a central amide bond. These three series provide different selectivity and physicochemical properties suitable for in-vivo studies.

IA-Lab: A MATLAB framework for efficient microscopy image analysis development, applied to quantifying intracellular transport of internalized peptide-drug conjugate.

This work presents a MATLAB-based software package for high-throughput microscopy image analysis development, making such development more accessible for a large user community. The toolbox provides a GUI and a number of analysis workflows, and can serve as a general framework designed to allow for easy extension. For a new application, only a minor part of the object-oriented code needs to be replaced by new components, making development efficient. This makes it possible to quickly develop solutions for analysis not available in existing tools. We show its use in making a tool for quantifying intracellular transport of internalized peptide-drug conjugates. The code is freely available as open source on GitHub (https://github.com/amcorrigan/ia-lab).

Targeted delivery for regenerative medicines: an untapped opportunity for drug conjugates.

Regenerative approaches are promising avenues to effectively cure diseases rather than merely treating symptoms, but are associated with concerns around proliferation in other organs. Given that targeted delivery holds the promise of delivering a drug precisely to its desired site of action, usually with the prospect of increasing the therapeutic index, it can be considered as an essential enabler of regenerative medicines. Although significant progress has been made predominantly in oncology for the delivery of cytotoxic drugs using antibody-drug conjugates (ADCs), the physiological conditions and safety requirements for regenerative medicines are very different. Drug conjugates need to be approached differently and, we herein suggest using a broader range of homing modalities and a specific framework to develop safe linkers.

Novel structures derived from 2-[[(2-pyridyl)methyl]thio]-1H-benzimidazole as anti-Helicobacter pylori agents, Part 1.

2-[[(2-Pyridyl)methyl]thio]-1H-benzimidazoles (2, sulfides) exhibit antibacterial properties that are selective for Helicobacter spp., but they also have an inherent susceptibility to metabolic oxidation to furnish 2-[[(2-pyridyl)methyl]sulfinyl]-1H-benzimidazoles (1), which act as proton pump inhibitors (PPIs). We have discovered five compounds with retained antibacterial potency and selectivity in which the overall framework of the sulfides 2 could be kept intact while structural modifications were made to remove PPI activity. These compounds, 2-[((2-methyl-3-(2-(2-(2-methoxyethoxy)ethoxy)ethylthio)phenyl)methyl)thio]-1H-benzimidazole (79), 2-[((2-methyl-3-(2-(2-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)ethoxy)ethylthio)phenyl)methyl)thio]-1H-benzimidazole (80), 2-[((2-methyl-3-((2-morpholino)ethylthio)phenyl)methyl)thio]-1H-benzimidazole (86), 2-[[[2-methyl-3-[2-(2-methyl-5-nitroimidazol-1-yl)ethylthio]phenyl]methyl]thio]-1H-benzimidazole (88), and 2-[[[2-methyl-3-[2-(1,2,4-triazol-1-yl)ethylthio]phenyl]methyl]thio]-1H-benzimidazole (89), had minimum bactericidal concentrations (MBCs) of 0.5, 0.5, 1, 2, and 4 microg/mL, respectively. The reported compounds are bactericidal with MBCs within 1 order of magnitude of MBCs of clinically used antimicrobials such as clarithromycin (0.1 microg/mL) or metronidazole (2-4 microg/mL) but differ from these inasmuch that they have an extremely narrow spectrum activity and appear to be species specific.