Recent trends of micro and nanostructured conducting polymers in health and environmental applications

Advanced Hybrid materials in electrochemical sensors: Combining MOFs and conducting polymers for environmental monitoring

The integration of conducting polymers (CPs) with metal-organic frameworks (MOFs) has arisen as a dynamic and innovative approach to overcome some intrinsic limitations of both materials, representing a transformative method to address the pressing need for high-performance environmental monitoring tools. MOFs, with their intricate structures and versatile functional groups, provide tuneable porosity and an extensive surface area, facilitating the selective adsorption of target analytes. Conversely, CPs, characterized by their exceptional electrical conductivity and redox properties, serve as proficient signal transducers. By combining these two materials, a novel class of hybrid materials emerges, capitalizing on the unique attributes of both components. These MOF/CP hybrids exhibit heightened sensitivity, selectivity, and adaptability, making them primordial in detecting and quantifying environmental contaminants. This review examines the synergy between MOFs and CPs, highlighting recent advancements, challenges, and prospects, thus offering a promising solution for developing advanced functional materials with tailored properties and multifunctionality to be applied in electrochemical sensors for environmental monitoring.

Biopolymers as a Potential Alternative for the Retention of Pollutants from Vinasse: An In Silico Approach

Vinasse, a waste from the bioethanol industry, presents a crucial environmental challenge due to its high organic matter content, which is difficult to biodegrade. Currently, no sustainable alternatives are available for treating the amount of vinasse generated. Conversely, biopolymers such as cellulose, carboxymethylcellulose, and chitosan are emerging as an interesting alternative for vinasse control due to their flocculating capacity against several organic compounds. This study seeks to determine the thermodynamic behavior of in silico interactions among three biopolymers (cellulose, carboxymethylcellulose, and chitosan) regarding 15 organic compounds found in vinasse. For this, the Particle Mesh Ewald (PME) method was used in association with the Verlet cutoff scheme, wherein the Gibbs free energy (ΔG) was calculated over a 50 ns simulation period. The findings revealed that cellulose showed a strong affinity for flavonoids like cyanidin, with a maximum free energy of -84 kJ/mol and a minimum of -55 kJ/mol observed with phenolic acids and other flavonoids. In contrast, chitosan displayed the highest interactions with phenolic acids, such as gallic acid, reaching -590 kJ/mol. However, with 3-methoxy-4-hydroxyphenyl glycol (MHPG), it reached an energy of -70 kJ/mol. The interaction energy for flavonoid ranged from -105 to -96 kJ/mol. Finally, carboxymethylcellulose (CMC) demonstrated an interaction energy with isoquercetin of -238 kJ/mol, while interactions with other flavonoids were almost negligible. Alternatively, CMC exhibited an interaction energy of -124 kJ/mol with MHPG, while it was less favorable with other phenolic acids with minimal interactions. These results suggest that there are favorable interactions for the interfacial sorption of vinasse contaminants onto biopolymers, indicating their potential for use in the removal of contaminants from the effluents of the bioethanol industry.

Preparation and characterization of PA/P(AA-co-AM) composite hydrogels via photopolymerization

The present study synthesized a deep eutectic solvent (DES) using acrylic acid (AA), acrylamide (AM), and choline chloride (ChCl), and added phytic acid (PA) as a filler. Subsequently, the PA/P(AA-co-AM) composite hydrogel was prepared under ultraviolet irradiation and used a photoinitiator. Characterization of the hydrogels was conducted using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study aimed to investigate the impact of PA on the mechanical properties, fatigue resistance, and electrical conductivity of the composite hydrogel. The findings demonstrated that as the mass fraction of PA increased, the compressive strength of the composite hydrogel gradually decreased, yet the fatigue resistance of the composite hydrogel increased. Specifically, after 10 cycles of compression, the resilience recovery rate of FP0 dropped from 86.9% to 70.4%, the maximum stress recovery rate of FP1 dropped from 97.9% to 89.4%, the maximum stress recovery rate of FP2 dropped from 94.4% to 86.6%, and the maximum stress recovery rate of FP3 dropped from 97.3% to 93%. Overall, this study offers a straightforward and efficient method for producing composite hydrogels with both fatigue resistance and electrical conductivity.

Chitosan-Based Scaffolds for the Treatment of Myocardial Infarction: A Systematic Review

Cardiovascular diseases (CVD), such as myocardial infarction (MI), constitute one of the world's leading causes of annual deaths. This cardiomyopathy generates a tissue scar with poor anatomical properties and cell necrosis that can lead to heart failure. Necrotic tissue repair is required through pharmaceutical or surgical treatments to avoid such loss, which has associated adverse collateral effects. However, to recover the infarcted myocardial tissue, biopolymer-based scaffolds are used as safer alternative treatments with fewer side effects due to their biocompatibility, chemical adaptability and biodegradability. For this reason, a systematic review of the literature from the last five years on the production and application of chitosan scaffolds for the reconstructive engineering of myocardial tissue was carried out. Seventy-five records were included for review using the "preferred reporting items for systematic reviews and meta-analyses" data collection strategy. It was observed that the chitosan scaffolds have a remarkable capacity for restoring the essential functions of the heart through the mimicry of its physiological environment and with a controlled porosity that allows for the exchange of nutrients, the improvement of the electrical conductivity and the stimulation of cell differentiation of the stem cells. In addition, the chitosan scaffolds can significantly improve angiogenesis in the infarcted tissue by stimulating the production of the glycoprotein receptors of the vascular endothelial growth factor (VEGF) family. Therefore, the possible mechanisms of action of the chitosan scaffolds on cardiomyocytes and stem cells were analyzed. For all the advantages observed, it is considered that the treatment of MI with the chitosan scaffolds is promising, showing multiple advantages within the regenerative therapies of CVD.

Design strategies, surface functionalization, and environmental remediation potentialities of polymer-functionalized nanocomposites

Inorganic nanoparticles (NPs) have a tunable shape, size, surface morphology, and unique physical properties like catalytic, magnetic, electronic, and optical capabilities. Unlike inorganic nanomaterials, organic polymers exhibit excellent stability, biocompatibility, and processability with a tailored response to external stimuli, including pH, heat, light, and degradation properties. Nano-sized assemblies derived from inorganic and polymeric NPs are combined in a functionalized composite form to import high strength and synergistically promising features not reflected in their part as a single constituent. These new properties of polymer/inorganic functionalized materials have led to emerging applications in a variety of fields, such as environmental remediation, drug delivery, and imaging. This review spotlights recent advances in the design and construction of polymer/inorganic functionalized materials with improved attributes compared to single inorganic and polymeric materials for environmental sustainability. Following an introduction, a comprehensive review of the design and potential applications of polymer/inorganic materials for removing organic pollutants and heavy metals from wastewater is presented. We have offered valuable suggestions for piloting, and scaling-up polymer functionalized nanomaterials using simple concepts. This review is wrapped up with a discussion of perspectives on future research in the field.

Synthesis, Characterization, and Antibacterial Potential of Poly(o-anisidine)/BaSO4 Nanocomposites with Enhanced Electrical Conductivity

The poly(o-anisidine)/BaSO4 nanocomposites were prepared by oxidative polymerization of o-anisidine monomer with BaSO4 filler for the potential antibacterial properties of the composite materials. To achieve the optimal and tunable properties of the nanocomposites, the ratio of BaSO4 filler was changed at the rates of 1%, 3%, 5%, 7%, and 10% with respect to matrix. Different analytical techniques, i.e., FTIR and UV-visible spectroscopy, were employed for functional identification and optical absorption of the poly(o-anisidine)/BaSO4 nanocomposites. The FTIR data revealed the significant interaction between POA and BaSO4, as well as the good absorption behavior of the UV-visible spectra. The conducting properties were controllable by varying the load percentage of the BaSO4 filler. Furthermore, different bacterial strains, i.e., Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive), were used to evaluate the antibacterial activity of the POA/BaSO4 nanocomposites. The largest zones of inhibition 0.8 and 0.9 mm were reached using 7% and 10% for Staphylococcus aureus and Pseudomonas aeruginosa, respectively.