Nanoscale geometry determines mechanical biocompatibility of vertically aligned nanofibers

Key role of adsorption site abundance in the direct electrochemical co-detection of estradiol and dopamine

Estradiol (E2) is a hormone that influences various aspects of women's health. Beyond its reproductive functions, E2 impacts neurotransmitter systems such as dopamine (DA). Vertically aligned carbon nanofibers (VACNFs) have shown good sensitivity, selectivity against ascorbic acid (AA) and uric acid (UA), biocompatibility, and reduced fouling in DA sensing. In this study, we explore the use of Ti-Ni-CNF electrodes with CNFs grown for 5 min and 30 min for the direct electrochemical co-detection of E2 and DA. The longer growth time led to a 142% increase in average CNF length and a 36% larger electroactive surface area. In E2 detection, the electrodes demonstrate a wide linear range of 0.05-10 µM and sensitivity of 0.016 and 0.020 µA/µM for Ti-Ni-CNF-5 min and Ti-Ni-CNF-30 min, respectively. The sensor performance remains largely unaffected even in the presence of other steroid hormones such as progesterone and testosterone. Co-detection of equimolar E2 and DA shows promising peak separation of 0.34 ± 0.01 V and repeatability after 10 measurements. A notable improvement in the E2/DA peak current ratio, from 0.53 ± 0.07 to 0.81 ± 0.16, was achieved with the increased CNF length. Our results demonstrate the influence of adsorption sites in electrochemical detection, especially for analytes such as E2 and DA that both rely on adsorption for oxidation. While detecting small and fluctuating physiological concentrations remains a challenge, these findings can be used in choosing and fabricating electrode materials for more accurate and accessible continuous hormone measurements, including the possibility of multianalyte sensing platforms.

Electrospun Konjac Glucomannan/Polyvinyl Alcohol Long Polymeric Filaments Incorporated with Tea Polyphenols for Food Preservations

In this study, nanofiber films were prepared by electrospinning technology with polyvinyl alcohol (PVA) and konjac glucomannan (KGM) as raw materials. Tea polyphenols (TPs) were incorporated in the above matrix, which increased physicochemical (thermal and mechanical characteristics) and antibacterial properties of the nanofiber films. The release behavior of phenolic compounds from PVA/KGM-TPs nanofiber films was determined in different food simulants; antioxidant and antibacterial activity of the films were also evaluated. The results showed that the addition of KGM increased the physical and chemical properties of the films. The tensile strength (TS) and elongation at break (EB) increased from 5.40 ± 0.33 to 10.62 ± 0.34 and from 7.24 ± 0.32 to 18.10 ± 0.91, respectively. PVA/KGM-TPs nanofiber films performed controlled release of TPs, with final release of 49.17% in 3% acetic acid, 43.6% in 10% ethanol, and 59.42% in 95% ethanol. The nanofiber films showed good antioxidation properties, with the free radical scavenging rate increasing from 1.33% to 25.61%, and good antibacterial properties with inhibition zones against E. coli and S. aureus of 24.33 ± 0.47 mm and 34.33 ± 0.94 mm, respectively. In addition, the as-prepared films showed significant preservation performance for raw bananas at 25 °C.

Toward a New Generation of Bio-Scaffolds for Neural Tissue Engineering: Challenges and Perspectives

Neural tissue engineering presents a compelling technological breakthrough in restoring brain function, holding immense promise. However, the quest to develop implantable scaffolds for neural culture that fulfill all necessary criteria poses a remarkable challenge for material science. These materials must possess a host of desirable characteristics, including support for cellular survival, proliferation, and neuronal migration and the minimization of inflammatory responses. Moreover, they should facilitate electrochemical cell communication, display mechanical properties akin to the brain, emulate the intricate architecture of the extracellular matrix, and ideally allow the controlled release of substances. This comprehensive review delves into the primary requisites, limitations, and prospective avenues for scaffold design in brain tissue engineering. By offering a panoramic overview, our work aims to serve as an essential resource, guiding the creation of materials endowed with bio-mimetic properties, ultimately revolutionizing the treatment of neurological disorders by developing brain-implantable scaffolds.