Multifactorial modeling and optimization of solution and electrospinning parameters to generate superfine polystyrene nanofibers

Cold atmospheric plasma modified polycaprolactone solution prior to electrospinning: A novel approach for improving quercetin-loaded nanofiber drug delivery systems

In this study, we present a novel approach for enhancing the performance of Quercetin-loaded nanofiber drug delivery systems through the modification of Polycaprolactone (PCL) solution using Cold Atmospheric Plasma (CAP) prior to electrospinning. CAP treatment was applied to PCL solutions for varying durations, namely, 0.5, 1, and 3 min. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) collectively demonstrate that CAP application and QU loading induce morphological changes in nanofibers, facilitating the creation of drug delivery systems with modified fiber diameters, devoid of bead formation. CAP treatment duration correlates with varying fiber diameters, with the longest treatment (3 min) producing the largest fibers (1324 ± 387 nm). Concurrently, the incorporation of quercetin (QU) into the PCL nanofibers resulted in reduced fiber diameter. These observations emphasize the pivotal role of CAP modification in tailoring nanofiber size and morphology. Notably, minimal peak shifts indicate no significant molecular structure changes in PCL nanofibers compared to PCL solutions, assuring the absence of unwanted chemical modifications or degradation during electrospinning. Furthermore, specific QU peaks are undetectable in Fourier-transform infrared (FTIR) spectra, suggesting dispersed or amorphous QU molecules within the nanofibers. Additionally, X-ray diffraction (XRD) results demonstrate that CAP treatment does not alter the crystalline structure of the PCL nanofiber drug delivery system. Crystalline planes of PCL remain unchanged, affirming stability under CAP treatment conditions. Water contact angles indicate that CAP treatment affects nanofiber hydrophobicity, with shorter CAP treatment times rendering more hydrophilic surfaces. Cumulative QU release percentages vary, with PCL/CAP-0.5-QU exhibiting the highest release at 56 ± 2.2 %, surpassing unmodified PCL/QU. Moreover, cell viability remains comparable or slightly increased when QU is incorporated into CAP-treated PCL nanofibers, suggesting potential mitigation of cytotoxic effects induced by CAP treatment. The combination of QU and CAP treatment enhances cancer cell viability reduction, QU release from nanofibers, and drug loading efficiency in a synergistic manner.

A conductometric enzymatic methanol sensor based on polystyrene - PAMAM dendritic polymer electrospun nanofibers

Methanol (MeOH) is a solvent and cleaning agent used in industry, but it is poisonous when ingested. The recommended release threshold for MeOH vapor is 200 ppm. We present a novel sensitive micro-conductometric MeOH biosensor created by grafting alcohol oxidase (AOX) onto electrospun polystyrene-poly(amidoamine) dendritic polymer blend nanofibers (PS-PAMAM-ESNFs) on interdigitated electrodes (IDEs). The analytical performance of the MeOH microsensor was evaluated using gaseous MeOH, ethanol, and acetone samples collected from the headspace above aqueous solution with known concentration. The sensor's response time (t_Res) fluctuates from 13 s to 35 s from lower to higher concentrations. The conductometric sensor has a sensitivity of 150.53 μS.cm-1 (v/v) for MeOH and a detection limit of 100 ppm in the gas phase. The MeOH sensor is 7.3 times less sensitive to ethanol and 136.8 times less sensitive to acetone. The sensor was verified for detecting MeOH in commercial rubbing alcohol samples.

Recent Progress in Protective Membranes Fabricated via Electrospinning: Advanced Materials, Biomimetic Structures, and Functional Applications

Electrospinning is a significant micro/nanofiber processing technology and has been rapidly developing in the past 2 decades. It has several applications, including advanced sensing, intelligent manufacturing, and high-efficiency catalysis. Here, multifunctional protective membranes fabricated via electrospinning in terms of novel material design, construction of novel structures, and various protection requirements in different environments are reviewed. To achieve excellent comprehensive properties, such as, high water vapor transmission, high hydrostatic pressure, optimal mechanical property, and air permeability, combinations of novel materials containing nondegradable/degradable materials and functional structures inspired by nature have been investigated for decades. Currently, research is mainly focused on conventional protective membranes with multifunctional properties, such as, anti-UV, antibacterial, and electromagnetic-shielding functions. However, important aspects, such as, the properties of electrospun monofilaments, development of "green electrospinning solutions" with high solid content, and approaches for enhancing adhesion between hydrophilic and hydrophobic layers are not considered. Based on this systematic review, the development of electrospinning for protective membranes is discussed, the existing gaps in research are discussed, and solutions for the development of technology are proposed. This review will assist in promoting the diversified development of protective membranes and is of great significance for fabricating advanced materials for intelligent protection.

Moisture-Wicking, Breathable, and Intrinsically Antibacterial Electronic Skin Based on Dual-Gradient Poly(ionic liquid) Nanofiber Membranes

Electronic skin can detect minute electrical potential changes in the human skin and represent the body's state, which is critical for medical diagnostics and human-computer interface development. On the other hand, sweat has a significant effect on the signal stability, comfort, and safety of electronic skin in a real-world application. In this study, by modifying the cation and anion of a poly(ionic liquid) (PIL) and employing a spinning process, a PIL-based multilayer nanofiber membrane (PIL membrane) electronic skin with a dual gradient is created. The PIL electronic skin is moisture-wicking and breathable due to the hydrophilicity and pore size-gradients. The intrinsically antimicrobial activities of PILs allow the safe collection of bioelectrical signals from the human body, such as electrocardiography (ECG) and electromyography (EMG). In addition, a robotic hand may be operated in real-time, and a preliminary human-computer interface can be accomplished by simple processing of the collected EMG signal. This study establishes a novel practical approach for monitoring and using bioelectrical signals in real-world circumstances via the multifunctional electronic skin.

Encapsulation of rosemary essential oil in zein by electrospinning technique

In this study, rosemary essential oil was encapsulated in zein-electrospun fibers at different concentrations of loading (0%, 2.5%, 5%, and 10% v/v). The chemical composition of rosemary essential oil was determined by GC-MS. The resultant zein-electrospun fibers were characterized by SEM, AFM, XRD, DSC, FTIR, and NMR. After being loaded with the essential oil, the fibers were evaluated for antimicrobial properties by the disc diffusion method against S. aureus (ATCC 1112) and E. coli (ATCC 1330). The release test was studied at pH values of 3 and 7.2 in phosphate buffer for 180 min. The GC-MS indicated that α-pinene occurred as a major compound in rosemary essential oil. Diameters of the zein-electrospun fibers increased in response to higher concentrations of rosemary essential oil. The AFM assay attributed a tubular morphology to the fibers. The physical status of rosemary essential oil in zein-electrospun fibers was determined by X-ray diffraction (XRD). DSC thermograms and FTIR spectra confirmed the existence of the rosemary essential oil in zein-electrospun fibers. FTIR spectra also indicated that adding rosemary essential oil to the fibers affected the secondary structure of zein protein. The NMR study showed that the electrospinning process did not change the secondary structure of zein. Disc diffusion indicated that zein-electrospun mats generated inhibition zones against S. aureus and E. coli. The release test revealed that pH values significantly affect the release of rosemary essential oil from fibers. The results demonstrated how loading zein-electrospun fibers with rosemary essential oil can benefit food packaging. PRACTICAL APPLICATION: In this study, electrospun fibers were produced from food-grade biopolymer to encapsulate rosemary essential oil. This product can be produced at industrial scale as an active food packaging/coating, controlled release, and delivery of the rosemary essential oil to food products and gastrointestinal. Also, it can be considered as a functional food to increase health.

Preparation of PVDF/FMBO composite electrospun nanofiber for effective arsenate removal from water

In this study, novel electrospun nanofibers (NFs) composed of organic polyvinylidine fluoride (PVDF) and inorganic Fe-Mn binary oxide (FMBO) nanoparticles were fabricated using an electrospinning technique for adsorptive decontamination of As(v) from polluted water. The NFs were prepared with doped solutions consisting of different weight ratios of PVDF/FMBO, in a NF matrix, ranging from 0 to 0.5. SEM, XRD, FTIR and TEM then characterized the NFs and FMBO particles. The XRD analysis indicated successful impregnation of FMBO nanoparticles in the NF matrix of the NFs investigated. An As(v) adsorption capacity as high as around 21.32 mg g-1 was obtained using the NF containing the highest amount of FMBO nanoparticles (designated as PVDF/FMBO 0.5). Furthermore, the adsorptive performance of the PVDF/FMBO 0.5 nanofiber could be easily regenerated using diluted alkaline solution (NaOH and NaOCl).

Effects of Jet Path on Electrospun Polystyrene Fibers

In this study we investigated the effects of jet path on the morphology and mat size of synthetic polystyrene (PS) fibers during the electrospinning process. In addition, the mechanism of the fiber mats, which were prepared by varying the solution concentration, was evaluated. The straight jet length, envelope cone and whipping frequency of each electrospun jet were studied using images captured by a high-speed photography camera. The results showed that higher solution concentrations led to longer straight jet lengths, smaller envelope cones and lower whipping frequencies. The diameter and surface morphology of the PS fibers were also characterized by scanning electron microscopy (SEM). It was found that fibers spun with higher solution concentrations exhibited larger diameters and diameter distributions because of their jet path features. Furthermore, the electrospun jets with higher concentrations increased elongation and produced smaller fiber mats and higher breaking forces as a result of their different jet paths, which was a consequence of varying the solution concentration.