Explorations into peptide nucleic acid contrast agents as emerging scaffolds for breakthrough solutions in medical imaging and diagnosis

Peptide nucleic acids (PNAs, nucleic acid analogues with a peptide backbone rather than a phosphoribosyl backbone) have emerged as promising chemical agents in antigene or antisense therapeutics, as splicing modulators or in gene editing. Their main benefits, compared to DNA or RNA agents, are their biochemical stability and the lack of negative charges throughout the backbone, leading to negligible electrostatic interaction with the strand with which they are hybridizing. As a result, hybridization of PNA strands with DNA or RNA strands leads to higher binding energies and melting temperatures. A lack of natural transporters, however, necessitates the formation of PNA-containing chimeras or the formulation of nanoparticular cell delivery methods. Here, we set out to explore the progress made in using imaging agents based on PNAs in diagnostic applications and highlight selected developments and challenges

Self-Assembled Materials Incorporating Functional Porphyrins and Carbon Nanoplatforms as Building Blocks for Photovoltaic Energy Applications.

As a primary goal, this review highlights the role of supramolecular interactions in the assembly of new sustainable materials incorporating functional porphyrins and carbon nanoplatforms as building blocks for photovoltaics advancements

Synthesis of sulfonamide conjugates of Cu(ii), Ga(iii), In(iii), Re(v) and Zn(ii) complexes: carbonic anhydrase inhibition studies and cellular imaging investigations

New sulfonamides and their metal complexes are reported, with a focus on porphyrin derivatives for simultaneous cellular optical imaging, radiolabelling and Carbonic Anhydrase inhibition capabilities.</p

Lysosomal tracking with a cationic naphthalimide using multiphoton fluorescence lifetime imaging microscopy

A naphthalimide-based chemosensing motif capable of turning on the fluorescence emission in solution and in vitro is reported.</p

A fluorescent Arg–Gly–Asp (RGD) peptide–naphthalenediimide (NDI) conjugate for imaging integrin <em>α_vβ₃in vitro</em>

We have developed a fluorescent peptide conjugate (TrpNDIRGDfK) based on the coupling of cyclo(RGDfK) to a new tryptophan-tagged amino acid naphthalenediimide (TrpNDI).</p

Investigations into the reactivity of lithium indenyl with alpha diimines with chlorinated backbones and formation of related functional ligands and metal complexes

Reaction between lithium indenyl and a chlorine substituted alpha diimine of the form [{Cl(NPh)2}C)]2 unexpectedly yielded the corresponding NH rearranged derivative [PhN(H)C(C9H6)]2 (1) rather than the predicted symmetrical α-diimine. This compound 1 was characterised by 1H NMR, 13C{1H} NMR and mass spectrometry, and additionally by X-ray diffraction. It was found that 1 was the first indene-substituted and symmetric secondary amine which was also highly fluorescent in DMSO. The reactivity of 1 towards simple inorganic and organometallic transition metals precursors based on the MX2 fragments, where M = Group 10 metals and X = halides or methyl groups, has been investigated. Surprisingly, the reaction with [PtMe2(COD)] led to the coupling reaction between the indenyl groups incorporated at the C–C ligand backbone and a new ligand (2) was discovered, in an attempt to synthesise the metal-linked diamine. Single crystal X-ray diffraction studies confirm this compound 2 to feature coupled indenyl residues and delocalised C–C bonds in the solid state. Structural authentication by X-ray crystallography showed compound 2 to be a very rare example of flat and extended aromatic organic molecule and mass spectrometry, IR and NMR spectroscopy were carried out to gain further insight into the solid state and solution phase structures. Further experiments to synthesise analogues of [PhN(H)C(Ind)]2 aiming to shift a likely equilibrium in favour the imine tautomer, by introducing bulky ortho substituents onto the benzene ring (R = Me, iPr) showed the presence of the imine tautomer to be increasingly favoured in 1H NMR spectra, with an increase in the steric bulk of the ortho substituents. However, the enamine tautomer is still observed to a minor extent even with isopropyl substituents and yields of these desired compounds were low on steric grounds

Correction:Microwave gallium-68 radiochemistry for kinetically stable bis(thiosemicarbazone) complexes: Structural investigations and cellular uptake under hypoxia (Dalton Transactions (2016) 45 (144-155))

We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under ‘cold’ and ‘hot’ biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. (68)Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration