Electrospun polycaprolactone (PCL) nanofibers have emerged as a promising material in diverse biomedical applications due to their various favorable features. However, their application in the field ...of biosensors such as point-of-care lateral flow assays (LFA) has not been investigated. The present study demonstrates the use of electrospun PCL nanofibers as a reaction membrane for LFA. Electrospun PCL nanofibers were treated with NaOH solution for different concentrations and durations to achieve a desirable flow rate and optimum detection sensitivity in nucleic acid-based LFA. It was observed that the concentration of NaOH does not affect the physical properties of nanofibers, including average fiber diameter, average pore size and porosity. However, interestingly, a significant reduction of the water contact angle was observed due to the generation of hydroxyl and carboxyl groups on the nanofibers, which increased their hydrophilicity. The optimally treated nanofibers were able to detect synthetic Zika viral DNA (as a model analyte) sensitively with a detection limit of 0.5 nM. Collectively, the benefits such as low-cost of fabrication, ease of modification, porous nanofibrous structures and tunability of flow rate make PCL nanofibers a versatile alternative to nitrocellulose membrane in LFA applications. This material offers tremendous potential for a broad range of point-of-care applications.
The growth of global food demand combined with the increased appeal to access different foods from every corner of the globe is forcing the food industry to look for alternative technologies to ...increase the shelf life. Essential oils (EOs) as naturally occurring functional ingredients have shown great prospects in active food packaging. EOs can inhibit the growth of superficial food pathogens, modify nutritious values without affecting the sensory qualities of food, and prolong the shelf life when used in food packaging as an active ingredient. Since 2016, various reports have demonstrated that combinations of electrospun fibers and encapsulated EOs could offer promising results when used as food packaging. Such electrospun platforms have encapsulated either pure EOs or their complexation with other antibacterial agents to prolong the shelf life of food products through sustained release of active ingredients. This paper presents a comprehensive review of the essential oil-loaded electrospun fibers that have been applied as active food packaging material.
(1) Background: Stem cells in combination with scaffolds and bioactive molecules have made significant contributions to the regeneration of damaged bone tissues. A co-culture system can be effective ...in enhancing the proliferation rate and osteogenic differentiation of the stem cells. Hence, the aim of this study was to investigate the osteogenic differentiation of human adipose derived stem cells when co-cultured with human osteoblasts and seeded on polycaprolactone (PCL):hydroxyapatite (HA) scaffold; (2) Methods: Human adipose-derived stem cells (ASC) and human osteoblasts (HOB) were seeded in three different ratios of 1:2, 1:2 and 2:1 in the PCL-HA scaffolds. The osteogenic differentiation ability was evaluated based on cell morphology, proliferation rate, alkaline phosphatase (ALP) activity, calcium deposition and osteogenic genes expression levels using quantitative RT-PCR; (3) Results: The co-cultured of ASC/HOB in ratio 2:1 seeded on the PCL-HA scaffolds showed the most positive osteogenic differentiation as compared to other groups, which resulted in higher ALP activity, calcium deposition and osteogenic genes expression, particularly Runx, ALP and BSP. These genes indicate that the co-cultured ASC/HOB seeded on PCL-HA was at the early stage of osteogenic development; (4) Conclusions: The combination of co-culture system (ASC/HOB) and PCL-HA scaffolds promote osteogenic differentiation and early bone formation.
Paper has recently found widespread applications in biomedical fields, especially as an alternative scaffolding material for cell cultures, owing to properties such as its fibrous nature, porosity ...and flexibility. However, paper on its own is not an optimal material for cell cultures as it lacks adhesion moieties specific to mammalian cells, and modifications such as hydrogel integration and chemical vapor deposition are necessary to make it a favorable scaffolding material. The present study focuses on modification of filter paper through electrospin-coating and dip-coating with polycaprolactone (PCL), a promising biomaterial in tissue engineering. Morphological analysis, evaluation of cell viability, alkaline phosphatase (ALP) activity and live/dead assays were conducted to study the potential of the modified paper-based scaffold. The results were compared to filter paper (FP) and electrospun PCL (ES-PCL) as reference samples. The results indicate that electrospin-coating paper is a simple and efficient way of modifying FP. It not only improves the morphology of the deposited electrospun layer through reduction of the fiber diameter by nearly 75%, but also greatly reduces the scaffold fabrication time compared to ES-PCL. The biochemical assays (Resazurin and ALP) indicate that electrospin-coated filter paper (ES-PCL/FP) provides significantly higher readings compared to all other groups. The live/dead results also show improved cell-distribution and cell-scaffold attachment all over the ES-PCL/FP.
In this article, a combination of far field electrospinning (FFES) and free-radical polymerization has been used to create a unique platform for protein immobilization via the physical attachment of ...biomolecules to the surface of the fiber mats. The large specific surface area of the fibers with its tailored chemistry provides a desirable platform for effective analyte-surface interaction. The detailed analysis of protein immobilization on a newly developed bio-receptive surface plays a vital role to gauge its advantages in bio-diagnostic applications. We relied on scanning electron microscopy (SEM), diameter range analysis, and X-ray photoelectron spectroscopy (XPS), along with thermal gravimetric analysis (TGA), water-in-air contact angle analysis (WCA), Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) to study our developed platforms and to provide valuable information regarding the presence of biomolecular entities on the surface. Detailed analyses of the fiber mats before and after antibody immobilization have shown obvious changes on the surface of the bioreceptive surface including: (i) an additional peak corresponding to the presence of an antibody in TGA analysis; (ii) extra FTIR peaks corresponding to the presence of antibodies on the coated fiber platforms; and (iii) a clear alteration in surface roughness recorded by AFM analysis. Confirmation analyses on protein immobilization are of great importance as they underlay substantial grounds for various biosensing applications.
Fiber-oriented film was prepared by electrospinning method using polyvinyl alcohol with stylbazol quaternized group (PVA-SbQ), and the formation behavior of polyiodine complex in fibers was ...investigated. From the UV-vis spectra and the Raman spectra, it was revealed that PVA-I5‾ was formed in the fiber orientated film after staining. It is presumed that in the fiber oriented film, the iodine complexes are aligned in one direction. It is considered that the polyiodine complex is inductively arranged with respect to the orientation of fibers, which contributes to the development of dichroism.
A combination of far-field electrospinning (FFES) and free-radical polymerization has been used to fabricate coated electrospun polymer fiber mats as a new type of biosensor platform. Poly ...(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) electrospun fibers were dip-coated with different compositions of poly methyl methacrylate-co-methacrylic acid (poly(MMA-co-MAA)). This synergistic approach utilizes large specific surface area of PHBV fibers and co-polymer coatings that feature an optimum concentration of surface carboxyl (-COOH) groups. The platform surface morphology, porosity and tunable hydrophobicity enhance biomolecular interactions via plurality of molecular forces. These customized fiber mats have been integrated into a newly designed 96-well plate called an "intrant enzyme-linked immunosorbent assay" or i-ELISA. I-ELISA allows colorimetric sandwich assay to be carried out without any modifications or additional steps in ELISA methodology. By introducing the fiber mats in fabrication of i-ELISA via extensions on the lid, we address some of the limitations of the previous designs while demonstrating an enhanced signal intensity up to 12 times higher than that of conventional assays. With improved sensitivity, specificity and accuracy in the detection of dengue virus, i-ELISA has proven to be a reliable platform for biomolecular recognition. The proposed fiber mat-assisted well plate in this study holds great potential as a universal approach for integration of different types of fiber mats with pre-designed specific properties in order to enhance the detection sensitivity of the assay.
Point-of-care biosensors are important tools developed to aid medical diagnosis and testing, food safety and environmental monitoring. Paper-based biosensors, especially nucleic acid-based lateral ...flow assays (LFA), are affordable, simple to produce and easy to use in remote settings. However, the sensitivity of such assays to infectious diseases has always been a restrictive challenge. Here, we have successfully electrospun polycaprolactone (PCL) on nitrocellulose (NC) membrane to form a hydrophobic coating to reduce the flow rate and increase the interaction rate between the targets and gold nanoparticles-detecting probes conjugates, resulting in the binding of more complexes to the capture probes. With this approach, the sensitivity of the PCL electrospin-coated test strip has been increased by approximately ten-fold as compared to the unmodified test strip. As a proof of concept, this approach holds great potential for sensitive detection of targets at point-of-care testing.
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•Electrospin-coating PCL onto nitrocellulose membrane of LFA can control the flow rate.•Electrospin-coating increases sensitivity of nucleic acid-based LFA by 10-fold.•A proof of concept shows potential in highly sensitive detection of viral nucleic acids.
In this study ultrasonic energy is applied for improving wet wool chlorination treatment one of the most well-established methods for reducing wool shrinking related to the felting. Sodium ...hypochlorite used for providing active chlorine in chlorination bath and samples chlorinated in the presence and absence of ultrasonic irradiation with equal processing parameters. The concentration of active chlorine during the treatment, shrinkage percentage, friction and some mechanical properties of treated samples determined and compared. Scanning Electron Microscope used for investigating the effects of different treatments on removal of wool scales. According to the results it was concluded that applying ultrasonic energy causes desirable mechanical and chemical effects in chlorination process. Cavitation phenomena causes more abrasion on wool surface especially on sharp places i.e., scales and the formation of hydrogen peroxide in ultrasonic bath managing the aggressive reaction of active chlorine on cuticle.
For the first time, the binary components of a self-healing epoxy system was developed comprising of a green acrylated epoxy resin and its thiol-based curing agent encapsulated in a poly (methyl ...methacrylate) (PMMA) shell by electrospraying technique. The field emission scanning electron microscopy images revealed that the two microcapsules formed were almost spherical with rough and irregular surfaces. The average diameter of microcapsules ranged from 1.165 to 1.418 μm for the two microcapsules. FTIR spectra and thermal analysis were used to investigate the encapsulation of acrylated epoxy resin and thiol curing agent in PMMA as well as the kinetics of crosslinking reaction between the two components. Based on FTIR spectra, the thiol curing agent was involved in the crosslinking reaction with the epoxy group (810 cm−1) and the C = C segment (1634 and 1613 cm−1) of acrylated epoxy resin. The DSC results indicated an exothermic peak (at 65 °C) proving that this system is efficient in self-healing epoxy resins for coating applications. Furthermore, the ability of epoxy coatings to protect the scratched coating substrate from corrosion media (the healing performance) without microcapsule, with dual microcapsules, single healing agent-containing microcapsule and single curing agent-containing microcapsule were also evaluated using potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS). The results were in line with the potentiodynamic polarization and the EIS. The highest self-healing efficiency (78%) was obtained for binary capsule concentration of 1%, indicating presence of sufficient amount of material to heal the cracks.
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