Metalloreceptors of the type L-M-L [L = (4′-(2-pyridyl)-2,2′:6′,2″-terpyridine), M = Co(II), Cu(II), Zn(II)] for the recognition of Fe 2+ ions

A manganese (II)-based coordinative dendrimer with robust efficiency in intracellular peptide delivery

Peptides have gained increasing interests as drug candidates in modern pharmaceutical industry, however, the development of peptide drugs acting on intracellular targets is limited due to their membrane impermeability. Here, we reported the use of metal-terpyridine based coordinative dendrimer for cytosolic peptide delivery. Among the investigated transition metal ions, Mn²⁺-coordinated polymer showed the highest delivery efficiency due to balanced peptide binding and release. It showed robust efficiency in the delivery of peptides with different charge property and hydrophobicity into various primary cells. The efficiency of Mn²⁺-terpyridine based polymer is superior to cell penetrating peptides such as oligoarginines. The material also delivered an autophagy-inducing peptide derived from Beclin-1 into cells and efficiently induced autophagy in the cells. This study provides a promising alternative to cell penetrating peptides for cytosolic peptide delivery.

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A Mn²⁺/terpyridine based polymer is rationally designed for cytosolic peptide delivery.

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The polymer shows robust efficiency in the delivery of 22 peptides with different properties into various primary cells.

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The polymer delivers an autophagy-inducing peptide derived from Beclin-1 into cells and efficiently induces autophagy.

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This study provides a promising alternative to cell penetrating peptides for cytosolic peptide delivery.

Terpyridine-Micelles for Inhibiting Bacterial Biofilm Development

Iron plays a critical role in bacterial infections and is especially critical for supporting biofilm formation. Until recently, Fe(III) was assumed to be the most relevant form of iron to chelate in therapeutic antimicrobial strategies due to its natural abundance under normal oxygen and physiologic conditions. Recent clinical data obtained from cystic fibrosis (CF) patients found that there is actually quite an abundance of Fe(II) present in sputum and that there exists a significant relationship between sputum Fe(II) concentration and severity of the disease. A biocompatible mixed micelle formed from the self-assembly of poly(lactic- co-glycolic acid)- block-methoxy poly(ethylene glycol) (PLGA- b-mPEG) and poly(lactic- co-glycolic acid)- block-poly(terpyridine)₅ [PLGA- b-p(Tpy)₅] polymers was prepared to chelate Fe(II) (Tpy-micelle). Tpy-micelles showed high selectivity for Fe(II) over Fe(III), decreased biofilm mass more effectively under anaerobic conditions at >4 μM Tpy-micelles, reduced bacteria growth in biofilms by >99.9% at 128 μM Tpy-micelles, effectively penetrated throughout a 1-day old biofilm, and inhibited biofilm development in a concentration-dependent manner. This study reveals that Fe(II) chelating Tpy-micelles are a promising addition to Fe(III) chelating strategies to inhibit biofilm formation in CF lung infections.