Bioapplications of Polythiophene-g-Polyphenylalanine-Covered Surfaces

Recent Advances and Biomedical Applications of Peptide-Integrated Conducting Polymers

Conducting polymers (CPs) are of great interests to researchers around the world in biomedical applications owing to their unique electrical and mechanical properties. Besides, they are easy to fabricate and have long-term stability. These features make CPs a powerful building block of modern biomaterials. Peptide functionalization has been a versatile tool for the development of CP-based biomaterials. With the aid of peptide modifications, the biocompatibility, target selectivity, and cellular interactions of CPs can be greatly improved. Reflecting these aspects, an increasing number of studies on peptide-integrated conducting polymers have been reported recently. In this review, various kinds of peptide immobilization strategies on CPs are introduced. Moreover, the aims of peptide modification are discussed in three aspects: enhancing the specific selectivity, avoiding nonspecific adhesion, and mimicking the environment of extracellular matrix. We highlighted recent studies in the applications of peptide-integrated CPs in electrochemical sensors, antifouling surfaces, and conductive biointerfaces. These studies have shown great potentials from the integration of peptide and CPs as a versatile platform for advanced biological and clinical applications in the near future.

A Review of Sensors and Biosensors Modified with Conducting Polymers and Molecularly Imprinted Polymers Used in Electrochemical Detection of Amino Acids: Phenylalanine, Tyrosine, and Tryptophan

Recently, the studies on developing sensors and biosensors-with an obvious interdisciplinary character-have drawn the attention of many researchers specializing in various fundamental, but also complex domains such as chemistry, biochemistry, physics, biophysics, biology, bio-pharma-medicine, and bioengineering. Along these lines, the present paper is structured into three parts, and is aimed at synthesizing the most relevant studies on the construction and functioning of versatile devices, of electrochemical sensors and biosensors, respectively. The first part presents examples of the most representative scientific research focusing on the role and the importance of the phenylalanine, tyrosine, and tryptophan amino acids, selected depending on their chemical structure and their impact on the central nervous system. The second part is dedicated to presenting and exemplifying conductor polymers and molecularly imprinted polymers used as sensitive materials in achieving electrochemical sensors and biosensors. The last part of the review analyzes the sensors and biosensors developed so far to detect amino acids with the aid of conductor polymers and molecularly imprinted polymers from the point of view of the performances obtained, with emphasis on the detection methods, on the electrochemical reactions that take place upon detection, and on the electroanalytical performances. The present study was carried out with a view to highlighting, for the benefit of specialists in medicine and pharmacy, the possibility of achieving and purchasing efficient devices that might be used in the quality control of medicines, as well as in studying and monitoring diseases associated with these amino acids.

Capsules from synthetic diblock-peptides as potential artificial oxygen carriers

The design of an encapsulation system consisting of a synthetic peptide which is fully biodegradable into non-toxic constituents. This system should be capable of encapsulating perfluorinated hydrocarbons and should be a promising basis for oxygen carriers to be used as artificial blood replacement. A diblock-peptide is synthesised following a phosgene-free method and characterised by ¹H-NMR. Subsequently, this diblock-peptide is self-assembled with perfluorodecalin (PFD) to form PFD-filled capsules as potential artificial oxygen carriers allowing for rapid oxygen uptake and release. The diblock-peptide Bu-PAsp₁₀-PPhe₁₀ is successfully synthesised and used to encapsulate PFD. The capsules have a spherical shape with an average diameter of 360 nm in stable aqueous dispersion. NMR measurements prove their physical capability for reversible uptake and release of oxygen. The resulting capsules are expected to be fully biodegradable and possibly could act as oxygen carriers for artificial blood replacement.

A treatise on Organophosphate pesticide pollution: Current strategies and advancements in their environmental degradation and elimination

Pesticides have been used in the field of agriculture ever since their role in protection of crops from pests which include four different categories namely insects, mites, rodents and animals has been identified. Organophosphate pesticides are one of the most extensively applied insecticides in the field of agriculture such that around 40% of all the pesticides that are produced and used commercially belong to this category. The main toxicological effect of these pesticides when exposed to a living being encompasses the irremediable inhibition of the acetylcholinesterase (AChE) enzyme which is involved in the neurotransmission of signals and hence its inhibition causes impairment of the respiratory tract and neuromuscular transmission. Apart from being used as a pesticide, organophosphates have also been applied as herbicides to some extent. The residues of these highly toxic chemicals have found route into the underground water system by seeping into the ground, in rivers where the agricultural run off water is disposed, and in the air when sprayed on the crops hence posing a threat to all the living strata exposed to these chemicals in various ways which are discussed further. Many significant studies have been carried out in order to evaluate the health risks associated with these pesticides which commonly include acute neurological disorders. This review emphasizes on the toxicological effects of organophosphate pesticides and the recent methods of detection that are used to identify trace amounts of organophosphate pesticides along with strategies which are used for their degradation.

Well-Defined Construction of Functional Macromolecular Architectures Based on Polymerization of Amino Acid Urethanes

Polypeptide synthesis was accomplished using the urethane derivatives of amino acids as monomers, which can be easily prepared, purified, and stored at ambient temperature without the requirement for special precautions. The urethanes of amino acids are readily synthesized by the N-carbamoylation of onium salts of amino acids using diphenyl carbonate (DPC). The prepared urethanes are then efficiently cyclized to produce amino acid N-carboxyanhydrides (NCAs). Thereafter, in the presence of primary amines, the ring-opening polymerization (ROP) of NCAs is initiated using the amines, to yield polypeptides with controlled molecular weights. The polypeptides have propagating chains bearing reactive amino groups and initiating chain ends endowed with functional moieties that originate from the amines. Aiming to benefit from these interesting characteristics of the polypeptide synthesis using the urethanes of amino acids, various macromolecular architectures containing polypeptide components have been constructed and applied as biofunctional materials in highly efficient antifouling coatings against proteins and cells, as biosensors for specific molecules, and in targeted drug delivery.

Conducting Polymer Grafting: Recent and Key Developments

Since the discovery of conductive polyacetylene, conductive electroactive polymers are at the focal point of technology generation and biocommunication materials. The reasons why this research never stops growing, are twofold: first, the demands from the advanced technology towards more sophistication, precision, durability, processability and cost-effectiveness; and second, the shaping of conducting polymer research in accordance with the above demand. One of the major challenges in conducting polymer research is addressing the processability issue without sacrificing the electroactive properties. Therefore, new synthetic designs and use of post-modification techniques become crucial than ever. This quest is not only advancing the field but also giving birth of new hybrid materials integrating merits of multiple functional motifs. The present review article is an attempt to discuss the recent progress in conducting polymer grafting, which is not entirely new, but relatively lesser developed area for this class of polymers to fine-tune their physicochemical properties. Apart from conventional covalent grafting techniques, non-covalent approach, which is relatively new but has worth creation potential, will also be discussed. The aim is to bring together novel molecular designs and strategies to stimulate the existing conducting polymer synthesis methodologies in order to enrich its fascinating chemistry dedicated toward real-life applications.

Ring opening polymerization of α-amino acids: advances in synthesis, architecture and applications of polypeptides and their hybrids

This review provides a comprehensive overview of the latest advances in the synthesis, architectural design and biomedical applications of polypeptides and their hybrids.

Rhodamine functionalized conducting polymers for dual intention: electrochemical sensing and fluorescence imaging of cells

We report here the electrochemical co-polymerization of two functional monomers; one containing fluorescent rhodamine dye (RF) and the other monomer having amine groups (RD), onto electroactive Indium Tin Oxide (ITO) glass.

Bioconjugation and Applications of Amino Functional Fluorescence Polymers

Synthesis and novel applications of biofunctional polymers for diagnosis and therapy are promising area involving various research domains. Herein, three fluorescent polymers, poly(p-phenylene-co-thiophene), poly(p-phenylene), and polythiophene with amino groups (PPT-NH₂ , PPP-NH₂ , and PT-NH₂ , respectively) are synthesized and investigated for cancer cell targeted imaging, drug delivery, and radiotherapy. Polymers are conjugated to anti-HER2 antibody for targeted imaging studies in nontoxic concentrations. Three cell lines (A549, Vero, and HeLa) with different expression levels of HER2 are used. In a model of HER2 expressing cell line (A549), radiotherapy experiments are carried out and results show that all three polymers increase the efficacy of radiotherapy. This effect is even more increased when conjugated to anti-HER2. In the second part of this work, one of the selected polymers (PT-NH₂ ) is conjugated with a drug model; methotrexate via pH responsive hydrazone linkage and a drug carrier property of PT-NH₂ is demonstrated on neuroblastoma (SH-SY5Y) cell model. Our results indicate that, PPT-NH₂ , PPP-NH₂ , and PT-NH₂ have a great potential as biomaterials for various bioapplications in cancer research.

A Novel Acetylcholinesterase Biosensor: Core-Shell Magnetic Nanoparticles Incorporating a Conjugated Polymer for the Detection of Organophosphorus Pesticides

To construct a sensing interface, in the present work, a conjugated polymer and core-shell magnetic nanoparticle containing biosensor was constructed for the pesticide analysis. The monomer 4,7-di(furan-2-yl)benzo[c][1,2,5]thiadiazole (FBThF) and core-shell magnetic nanoparticles were designed and synthesized for fabrication of the biosensing device. The magnetic nanoparticles were first treated with silica and then modified using carboxyl groups, which enabled binding of the biomolecules covalently. For the construction of the proposed sensor a two-step procedure was performed. First, the poly(FBThF) was electrochemically generated on the electrode surface. Then, carboxyl group modified magnetic nanoparticles (f-MNPs) and acetylcholinesterase (AChE), the model enzyme, were co-immobilized on the polymer-coated surface. Thereby, a robust and novel surface, conjugated polymer bearing magnetic nanoparticles with pendant carboxyl groups, was constructed, which was characterized using Fourier transform infrared spectrometer, cyclic voltammetry, scanning electron microscopy, and contact angle measurements. This novel architecture was then applied as an immobilization platform to detect pesticides. To the best of our knowledge, a sensor design that combines both conjugated polymer and magnetic nanoparticles was attempted for the first time, and this approach resulted in improved biosensor characteristics. Hence, this approach opens a new perspective in the field of enzyme immobilization and sensing applications. Paraoxon and trichlorfon were selected as the model toxicants. To obtain best biosensor performance, optimization studies were performed. Under optimized conditions, the biosensor in concern revealed a rapid response (5 s), a low detection limit (6.66 × 10(-3) mM), and high sensitivity (45.01 μA mM(-1) cm(-2)). The KM(app) value of poly(FBThF)/f-MNPs/AChE were determined as 0.73 mM. Furthermore, there was no considerable activity loss for 10 d for poly(FBThF)/f-MNPs/AChE biofilm.

Synthesis and application of a novel poly-l-phenylalanine electroactive macromonomer as matrix for the biosensing of ‘Abused Drug’ model

The synthesis and biosensing application of a novel poly-l-phenylalanine-bearing electroactive macromonomer has been carried out.

Synthesis of a novel, fluorescent, electroactive and metal ion sensitive thienylpyrrole derivate

A new novel, pyrene modified, thiophene–pyrrole based monomer was synthesized via a Schiff base reaction. It showed sensitive fluorescence changes when interacting with metal ions. Moreover, the electrochemical properties of its polymer were investigated.