Dual‐Fluorescent Nanoscale Coordination Polymers via a Mixed‐Ligand Synthetic Strategy and Their Use for Multichannel Imaging

Abstract

Two rationally-designed strategies for covalent bonding of fluorescent dyes in coordination polymer nanoparticles to achieve bifunctional fluorescent nanostructures have been developed. The first strategy was based on the synthesis of the coordination polymers structured as nanoparticles by coordination of Co II ions to two different catechol ligands containing free functional chemical groups (dopamine and 3,4dihydroxybenzaldehyde), and a bis-imidazol ligand (1,4bis(imidazole-1-ylmethyl)benzene, bix). Subsequently, different dyes namely fluorescein isothiocyanate (FITC), 1-pyrenebutanoic acid hydrazide (PBH) or Alexa Fluor ® 568 (A568) could be sequentially attached to the nanoparticles surface. The second strategy was focused on the pre-functionalization of catechol ligands with the corresponding dyes and afterward the coordination with the metal ions in presence of bix. In vitro studies demonstrated the internalization of the bifunctional nanoparticles and the persistence of the fluorescent properties after cell uptake without dye leaching.[a]

Dual T1/T2 Nanoscale Coordination Polymers as Novel Contrast Agents for MRI: A Preclinical Study for Brain Tumor

“…This is not restricted to contrast enhancement, as they could be also used as nanocarriers for tumor-drug release and therapy in addition to diagnosis. 75,76 3.5.3. Biodistribution.…”

“…Thus, these nanoparticles present a clear interest for future studies, bearing a strong translational potential. This is not restricted to contrast enhancement, as they could be also used as nanocarriers for tumor-drug release and therapy in addition to diagnosis. , …”

Thiol-yne click reaction: an interesting way to derive thiol-provided catechols

“…On the other hand, in recent years, an increasing number of works have focused on the synthesis of new bioinspired catechol-based molecules, which have shown to be useful in the fabrication of novel functional materials, 19 including adhesives, 20 capsules, 21 coatings, 22 hydrogels 23 and in the formation of coordination polymer nanoparticles (CNPs). 24 However, despite the extraordinary characteristics of catechol-derived structures, their preparation is challenging mainly due to the vulnerability of catechol to oxidation. As a result, only a few synthetic methodologies have been described and even among these, relatively lengthy synthetic routes, comprising protection/deprotection of the catechol ring, harsh reaction conditions and overall poor atom economy have been reported.…”

Photoactivable Ruthenium-Based Coordination Polymer Nanoparticles for Light-Induced Chemotherapy

“…The stoichiometric deviation from the theoretical expected ratio of the components for a linear polymer ([Ru(biqbpy)]: BIS = 1:1) is quite archetypal for CPNs. This is attributed to the out-of-equilibrium synthetic conditions that lead to the fast precipitation process of oligomeric species with different stoichiometry [45,46,48,49,56,57]. In any case, the Ru complex payload value of 41 wt % is more than four-fold higher than most conventional metallodrug-loaded polymer carriers known to date (typically less than 10%) [58].…”

“…The polymerization process We have achieved this challenge with the synthesis of CPNs containing [Ru(biqbpy) (dmso)Cl]Cl monomer (complex 1, where biqbpy = stands for 6,6 -bis[N-(isoquinolyl)-1amino]-2,2 -bipyridine), which is known to form cytotoxic aqueous active species [Ru(biqbpy) (H 2 O) 2 ] 2+ upon blue or green light activation [14]. The polymerization process was performed using the photocleavable bis(imidazol-1-yl)-hexane (BIS) ligand and following a methodology previously described for the synthesis of non-photoactive CPNs of relevance in biological applications [47][48][49][50].…”