Amphiphilic polypyrrole-poly(Schiff base) copolymers with poly(ethylene glycol) side chains: synthesis, properties and applications

Abstract

New amphiphilic poly(ethylene glycol) (PEG)-grafted random intrinsically conducting copolymers which combine three different functionalities have been engineered, prepared and characterized. Specifically, these "rod-coil" type copolymers bear conducting polypyrrole (PPy) and poly(Schiff base) (PSB) sequences randomly distributed in their backbones; hydrophilic grafted side chains consisting of well-defined PEG chains are attached to the PSB units. Basically, the synthesis of the copolymers is conducted sequentially by employing the "macromonomer" technique via electrochemical co-polymerization of a bis ( pyrrole) benzoic Schiff base-containing PEG macromonomer with pyrrole monomers. After investigation of the chemical and electrochemical properties of the synthesized copolymers, their advantages of multi-functionality in terms of biomedical applications have been demonstrated. More specifically, the conjugated PPy and PSB sequences enabled the grafted copolymers to exhibit great ability to catalyse the oxidation of serotonin, an important neurotransmitter found in blood platelets and in the central nervous systems of animals and humans. On the other hand, the enhanced biocompatibility in comparison with bare PPy is due to the presence of PEG side chains, while bacteriostatic activity against both Gram-negative and Gram-positive bacteria is imparted by the synergistic combination of the polycationic character of the PPy main chain with the benzoic Schiff base functional groups and with the bent-shaped architecture of the facially amphiphilic PSB sequences, respectively. Accordingly, these grafted copolymers are promising materials for developing implantable electrodes for serotonin detection which present the abovementioned characteristics. c "Petru

An amphiphilic, heterografted polythiophene copolymer containing biocompatible/biodegradable side chains for use as an (electro)active surface in biomedical applications

“…The new amphiphilic heterografted copolymer was synthesized by combining the so-called "macromonomer" or "grafting through" technique, 28,29,[33][34][35] via oxidative polycondensation reaction of an equimolecular mixture of two thiophene-ended macromonomers (Scheme 1), a classical method for CPs chemical synthesis. The hydrophilic macromonomer, Th-PEG, was synthesized by chain-end functionalization method, through Steglich esterification of hydroxyl group of PEG2000 (Scheme 1A), being the first time it has been reported.…”

“…In recent years, we have developed several amphiphilic and biocompatible PTh-based grafted copolymers using the "grafting-through" approach (also named macromonomer method). [27][28][29] For this purpose, chemically synthesized thiophene (Th)-based macromonomers bearing a PEG or PCL side chains with low molecular weight have been polymerized, or copolymerized to space out the biocompatible side blocks, via electrochemical copolymerization. 14,[27][28][29] Moreover, the applicability of these materials as bioactive cellular matrices and electroactive bioadhesive surfaces for biomedical and biotechnological applications, respectively, was demonstrated.…”

“…[27][28][29] For this purpose, chemically synthesized thiophene (Th)-based macromonomers bearing a PEG or PCL side chains with low molecular weight have been polymerized, or copolymerized to space out the biocompatible side blocks, via electrochemical copolymerization. 14,[27][28][29] Moreover, the applicability of these materials as bioactive cellular matrices and electroactive bioadhesive surfaces for biomedical and biotechnological applications, respectively, was demonstrated. 14,[27][28][29] Furthermore, the PTh-based graft copolymers bearing low molecular weight PCL chains showed a sensitive and selective capability for dopamine (DA) detection, proving that such hybrid materials are potential candidates for the fabrication of implantable DA sensors.…”

“…14,[27][28][29] Moreover, the applicability of these materials as bioactive cellular matrices and electroactive bioadhesive surfaces for biomedical and biotechnological applications, respectively, was demonstrated. 14,[27][28][29] Furthermore, the PTh-based graft copolymers bearing low molecular weight PCL chains showed a sensitive and selective capability for dopamine (DA) detection, proving that such hybrid materials are potential candidates for the fabrication of implantable DA sensors. 28 Nowadays, the development of biosensing devices for the detection of β-nicotinamide adenine dinucleotide (NADH) has gained interest because of its participation as enzymatic cofactor in more than 300 dehydrogenases and as electron carrier in cell processes associated to energy production.…”

Predicting Adsorption Energies Using Multifidelity Data

“…As CV is typically employed to identify the redox state of biomolecules, as for example neurotransmitters (e.g. dopamine 18,19 and serotonine 20 ), glucose, 21,22 and opioids, 23,24 we have focused our attention in nicotinamide adenine dinucleotide (NADH). This biomolecule plays an important role not only as cofactor for numerous deshydrogenase enzymes but also in the electron transfer chain in living organisms.…”