Supported liquid phase extraction using wetted nanofiber discs as a simple approach for in-vial extraction of chlorophenols and insecticides from river water prior to HPLC-DAD analysis.

Background: A novel supported liquid extraction approach using small polymeric nanofibrous discs was demonstrated and applied to the analysis of real river water. Nanofibrous discs were tested to extract model mixture of 9 common water contaminants 4-nitrophenol, various chlorophenols, bisphenol A, permethrin, and fenoxycarb featuring a wide range of log P values (1.9-6.

Advanced nanofibrous sorbents for the extraction of pollutants from river water and protein-containing matrices.

The extraction efficiencies of thirty types of fibers produced by meltblown, alternating current electrospinning, and meltblown-co-electrospinning technologies were tested as advanced sorbents for on-line solid-phase extraction in a high-performance liquid chromatography system have been tested and compared with a commercial C18 sorbent. The properties of each fiber, which were often depended on the production process, and their applicability were demonstrated with the extraction of the model analytes nitrophenols and chlorophenols from various matrices including river water and to purify complex matrix human serum and bovine serum albumin from macromolecular ballast. Polycaprolactone fibers outperformed other polymers and were selected for subsequent modifications including (i) incorporation of hybrid carbon nanoparticles, i.

Comparative study of drug release from electrospun nanofibers loaded with clotrimazole via two different approaches using a fully automated sequential injection system.

The development of new drug delivery platforms including the use of nanotechnology has been found of great interest in recent years. Two different loading approaches of the model antimycotic drug clotrimazole into the nanofibrous polycaprolactone and polydioxanone structures including electrospinning of a drug-polymer blend and impregnation of nanofibers with drug have been tested. The final amount of clotrimazole in the nanofibrous materials was determined by HPLC analysis and Raman spectroscopy.

Large-Scale Development of Antibacterial Scaffolds: Gentamicin Sulfate-Loaded Biodegradable Nanofibers for Gastrointestinal Applications.

The ever-increasing demands of modern medicine drive the development of novel drug delivery materials. In particular, nanofibers are promising for such materials due to their favorable properties. However, most development is still carried out through laboratory techniques that do not allow extensive and reproducible characterization of materials, which slows medical research.

Stirred discs from polycaprolactone nanofibers highly doped with graphene for straightforward preconcentration of pollutants in environmental waters.

A novel sorbent for solid phase extraction (SPE) based on hybrid nanofibrous polycaprolactone containing graphene nanoparticles has been prepared. The preparation of hybrid polymer nanofibers with a very high 1:1 polymer/graphene ratio was achieved for the first time using alternating current electrospinning. The final appearance of these nanofibers was a thick porous layer that was cut into the shape of easy-to-handle extraction discs.

Antiadhesive Nanofibrous Materials for Medicine: Preventing Undesirable Tissue Adhesions.

Undesirable postoperative tissue adhesions remain among the most common complications after surgery. Apart from pharmacological antiadhesive agents, various physical barriers have been developed in order to prevent postoperative tissue adhesions. Nevertheless, many introduced materials suffer from shortcomings during application.

Small nanofibrous disks for preconcentration of environmental contaminants followed by direct in-vial elution and chromatographic determination.

A novel method for the extraction of river water contaminants as model analytes of ranging polarities, including bisphenols A, C, S, Z, fenoxycarb, kadethrin, and deltamethrin, using small compact fibrous disks has been developed and validated. Polymer nanofibers and microfibers prepared from poly(3-hydroxybutyrate), polypropylene, polyurethane, polyacrylonitrile, poly(lactic acid), and polycaprolactone doped with graphene were evaluated in terms of extraction efficiency, selectivity, and stability in organic solutions. Our novel extraction procedure comprised preconcentration of analytes from 150 mL river water to 1 mL of eluent using a compact nanofibrous disk freely vortexed in the sample.

The Injection Molding of Biodegradable Polydioxanone-A Study of the Dependence of the Structural and Mechanical Properties on Thermal Processing Conditions.

Recent years have observed a significant increase in the use of degradable materials in medicine due to their minimal impact on the patient and broad range of applicability. The biodegradable polymer Polydioxanone (PDO) provides a good example of the use of such one polymer that can represent the aforementioned medical materials in the field of medicine, due to its high level of biocompatibility and interesting mechanical properties. PDO is used to produce absorbable medical devices such as sutures and stents, and is also suitable for the fabrication of certain orthopedic implants.

The Combination of Hydrogels with 3D Fibrous Scaffolds Based on Electrospinning and Meltblown Technology.

This study presents the advantages of combining three-dimensional biodegradable scaffolds with the injection bioprinting of hydrogels. This combination takes advantage of the synergic effect of the properties of the various components, namely the very favorable mechanical and structural properties of fiber scaffolds fabricated from polycaprolactone and the targeted injection of a hydrogel cell suspension with a high degree of hydrophilicity. These properties exert a very positive impact in terms of promoting inner cell proliferation and the ability to create compact tissue.

Comparing adsorption performance of microfibers and nanofibers with commercial molecularly imprinted polymers and restricted access media for extraction of bisphenols from milk coupled with liquid chromatography.

Advanced solid phase extraction (SPE) fibrous sorbents including polyethylene, polypropylene poly (hydroxybutyrate), and polyamide 6 nanofibers, polycaprolactone microfibers/nanofibers, polycaprolactone microfibers/polyvinylidene difluoride nanofibers, and poly (hydroxybutyrate) microfibers/polypropylene microfibers composites, as well as commercial molecularly imprinted polymers and restricted access media sorbent were compared in terms of bisphenols extraction from milk and their clean-up efficiency. Three on-line SPE-HPLC methods were completely validated for the extraction and detection of bisphenols A, AF, C, A diglycidyl ether, and F diglycidyl ether in bovine milk. Polycaprolactone composite nanofibers compared favorably to restricted access media, enabled excellent clean-up of bisphenols from the proteinaceous matrix, and yielded recoveries 98.

Nanofibrous Online Solid-Phase Extraction Coupled with Liquid Chromatography for the Determination of Neonicotinoid Pesticides in River Waters.

Polymeric nano- and microfibers were tested as potential sorbents for the extraction of five neonicotinoids from natural waters. Nanofibrous mats were prepared from polycaprolactone, polyvinylidene fluoride, polystyrene, polyamide 6, polyacrylonitrile, and polyimide, as well as microfibers of polyethylene, a polycaprolactone nano- and microfiber conjugate, and polycaprolactone microfibers combined with polyvinylidene fluoride nanofibers. Polyimide nanofibers were selected as the most suitable sorbent for these analytes and the matrix.

Polycaprolactone Composite Micro/Nanofibrous Material as an Alternative to Restricted Access Media for Direct Extraction and Separation of Non-Steroidal Anti-Inflammatory Drugs from Human Serum Using Column-Switching Chromatography.

Application of the poly-ɛ-caprolactone composite sorbent consisting of the micro- and nanometer fibers for the on-line extraction of non-steroidal anti-inflammatory drugs from a biological matrix has been introduced. A 100 μL human serum sample spiked with ketoprofen, naproxen, sodium diclofenac, and indomethacin was directly injected in the extraction cartridge filled with the poly-ɛ-caprolactone composite sorbent. This cartridge was coupled with a chromatographic instrument via a six-port switching valve allowing the analyte extraction and separation within a single analytical run.

The Optimization of Alternating Current Electrospun PA 6 Solutions Using a Visual Analysis System.

The electrospinning process that produces fine nanofibrous materials have a major disadvantage in the area of productivity. However, alternating current (AC) electrospinning might help to solve the problem via the modification of high voltage signal. The aforementioned productivity aspect can be observed via a camera system that focuses on the jet creation area and that measures the average lifespan.

The role of pKa, log P of analytes, and protein matrix in solid-phase extraction using native and coated nanofibrous and microfibrous polymers prepared via meltblowing and combined meltblowing/electrospinning technologies.

Effect of physicochemical properties including dissociation constant (pKa) and partition coefficient (log P) of the compounds on their extraction efficiency in sample preparation using fibrous polymer sorbents has been demonstrated. Poly-ε-caprolactone as meltblown/electrospun composite fibers, and polypropylene, polyethylene, poly(3-hydroxybutyrate), poly(lactic acid), and polyamide 6 in the meltblown fiber format were used as sorbents in solid-phase extraction. In addition, the polycaprolactone fibers were coated with dopamine, dopamine combined with heparin, and tannin, respectively, to modify their extraction properties.

A PVDF electrospun antifibrotic composite for use as a glaucoma drainage implant.

Glaucoma disease therapy frequently involves the application of a glaucoma implant. This approach is effective in terms of reducing the intraocular pressure via the filtering of intraocular fluid from the anterior chamber into the drainage pathways. The basic properties of such implants comprise of long-term stability and the filtering of fluids without the occurrence of undesirable blockages.

Stenting to prevent esophageal stricture after circumferential endoscopic submucosal dissection: an experimental study.

Circular ESD (CESD) is a treatment option for patients with extensive early esophageal cancer. Its major drawback is the development of a stricture. Stenting may represent an attractive prevention strategy.

On-line polydopamine coating as a new way to functionalize polypropylene fiber sorbent for solid phase extraction.

Effective process, including a cartridge packing polypropylene fiber sorbent modified by following on-line polydopamine coating, for on-line solid phase extraction in 2D UHPLC system has been developed. Hydrophobic surface of mechanically stable polypropylene fibers was hydrophilized using an automated and reproducible in situ coating process to enable good wettability and effective extraction of polar compounds. Polymerization mixture consisting dopamine and TRIS buffer was circulated through the cartridge containing polypropylene fibers using a peristaltic pump to achieve polymerization.

Impact of Various Sterilization and Disinfection Techniques on Electrospun Poly-ε-caprolactone.

Electrospun materials made from biodegradable polycaprolactone are used widely in various tissue engineering and regenerative medicine applications because of their morphological similarity to the extracellular matrix. However, the main prerequisite for the use of such materials in clinical practice consists of the selection of the appropriate sterilization technique. This study is devoted to the study of the impact of traditional sterilization and disinfection methods on a nanofibrous polycaprolactone layer constructed by means of the needleless electrospinning technique.

Poly-ε-caprolactone Nanofibrous Polymers: A Simple Alternative to Restricted Access Media for Extraction of Small Molecules from Biological Matrixes.

Poly-ε-caprolactone nanofibrous polymer has been used as an alternative to restricted access media for extraction of protein-containing biological samples and direct transfer in the chromatographic system. Three commercial cartridges differing in length and internal diameter have been manually packed with the composite material prepared from poly-ε-caprolactone nanofibers coated on poly-ε-caprolactone microfibrous scaffold and connected to the column-switching chromatographic system. Bovine milk and human serum (25 μL) spiked with a mixture of methyl-, ethyl-, propyl-, and butylparaben in a concentration range of 1-100 μg mL were online extracted using the cartridge-containing fibers.

ac Bubble Electrospinning Technology for Preparation of Nanofibrous Mats.

This study deals with a new combination of alternating current (ac) electrospinning and bubble electrospinning. Research devoted to the combination of these two methods for the preparation of nanofibrous and microfibrous mats has been carried out. The design, construction, and description of bubble electrospinning are described in this article.

3D-Printed Magnetic Stirring Cages for Semidispersive Extraction of Bisphenols from Water Using Polymer Micro- and Nanofibers.

A magnetic stirring device allowing semidispersive solid phase extraction of eight bisphenols (A, AF, AP, C, BP, G, M, and Z) from river waters using polymer nano- and microfibers followed by HPLC with spectrophotometric detection has been developed and applied. About 50 mg of fibers was placed in a round, cage-like housing consisting of two identical 3D printed pieces that were locked together by a magnetic stirring bar. Magnetic stirring action of the cage devices enabled highly efficient interaction of the fibers housed inside with the aqueous samples and analyte transfer without risking fiber compaction and/or damaging.

Polycaprolactone nanofibers functionalized with a dopamine coating for on-line solid phase extraction of bisphenols, betablockers, nonsteroidal drugs, and phenolic acids.

Polycaprolactone composite nanofibers coated with a polydopamine layer are introduced as a new type of absorption material for on-line solid phase extraction (SPE) in chromatographic system. A hybrid technology combining the electrospinning and melt blowing was used for the preparation of 3D-structured microfiber/nanofibrous polycaprolactone composite. The dopamine coating was then applied to functionalize the micro/nanofibers.

Novel nanofibrous sorbents for the extraction and determination of resveratrol in wine.

On-line SPE HPLC method using nanofibrous sorbents for the extraction and determination of resveratrol in wine was developed and validated. Different types of nanofibrous and microfibrous polymers were tested and compared with commercial monolithic C18 sorbent. Polyamide and polyacrylonitrile nanofibers and composite materials composed of respective polycaprolactone and poly(vinylidene difluoride) nanofibers at microfibrous scaffold were included among tested materials.

Screening of extraction properties of nanofibers in a sequential injection analysis system using a 3D printed device.

A novel application of the three-dimensional printing technology for the automation of solid phase extraction procedures in a low-pressure sequential injection analysis system is presented. A 3D printed device was used as a housing for nanofiber membranes in solid phase extraction. The applicability of the device is demonstrated with the extraction of substances of various physical-chemical properties.

A comparison study of nanofiber, microfiber, and new composite nano/microfiber polymers used as sorbents for on-line solid phase extraction in chromatography system.

Three different approaches has been used to obtain nano/micro fibers and their diversity and extraction properties were examined. The effect of their structure on stability in an ultra-high-performance liquid chromatography (UHPLC) system during on-line SPE procedure was monitored. Five types of various nano/micro fiber polymers were used as sorbents: polyamide 6 nanofibers, polyvinylidene difluoride nanofibers, polyethylene microfibers, and two new polycaprolactone microfiber/nanofiber and polycaprolactone microfibers/polyvinylidene difluoride nanofibers composite polymers.