Glutaraldehyde Vapor Research Articles

COMPARISON OF CREATININE DEIMINASE IMMOBILIZATION METHODS FOR DESIGN OF POTENTIOMETRIC BIOSENSORS FOR CREATININE DETECTION

The main analytical characteristics of the potentiometric biosensor based on creatinine deiminase were investigated when working with model samples, and comparison for various enzyme immobilization methods was made. It was found that all sensors are characterized by a similar operating range, response time and high operational stability. At the same time, the sensitivity of the biosensor to creatinine was 2 times higher for the option of immobilization in a drop of glutaraldehyde. Storage stability was high for all immobilization methods, with the exception of immobilization in glutaraldehyde vapors, when the value of the sensor response dropped by 50% after 100 days of storage. The dependences on the experimental conditions were typical for enzyme biosensors and did not depend on the enzyme immobilization method. The linear range of creatinine determination is quite suitable for further work with real blood samples and dialysis fluid when diluted 10 times.

Protein Nanospheres and Nanofibers Prepared by Ice-Templating for the Controlled Release of Hydrophobic Drugs.

Protein scaffolds play a vital role in drug delivery systems. However, few research studies have been focused on loading hydrophobic drugs on protein scaffolds in biomedical fields. Here, we report on the development of protein microspheres and nanofibers by a simple ice-templating approach and their use as scaffolds for the controlled release of hydrophobic drugs, with bovine serum albumin (BSA) as the model protein and curcumin as the model hydrophobic drug. The BSA scaffolds display the unique nanofibrous and microspherical structures. This is a surprising discovery because there has been no report on the formation of microspheres via simple ice-templating of solutions or suspensions. To further understand the formation of microspheres by this approach, lysozyme, papain, and their composites with BSA are also studied. It is speculated that nanoparticles are first formed in aqueous BSA solution, attributed to the overlapping of hydration layers and autoassembly of inner hydrophobic cores of BSA globular molecules. Nanoprecipitation and soaking evaporation approaches are then used to load curcumin into the BSA scaffolds, followed by cross-linking with glutaraldehyde vapor to improve stability in an aqueous medium. The controlled release of curcumin is demonstrated, paving the way for various hydrophobic drugs loaded into this biodegradable and nonimmunogenic protein scaffold for potential treatments of diverse diseases.

Characterization of Fibers Prepared by Centrifugal Spinning from Biotechnologically Derived Chicken Gelatin.

The application of biopolymer-based materials is increasing due to better sustainability and environmental protection properties. Gelatin fibers have a specific surface and high porosity, which is why their use in medicine and the food industry is being researched. This article explores the potential of centrifugal spinning to produce gelatin fibers. Gelatin for fiber preparation was obtained from a non-traditional source of collagen (chicken by-products) using a unique enzymatic process. The fiber quality was compared with those prepared from gelatins produced from traditional collagen tissues (porcine, bovine). The results showed that fibers cross-linked with glutaraldehyde vapor preserved their structure even in contact with water. Using a cross-linker controlled swelling ability and solubility while maintaining the fiber structure. On the contrary, uncross-linked gelatin fibers were water soluble due to a high surface-to-volume ratio, facilitating water penetration and dissolution. Scanning electron microscopy (SEM) provided a clearer picture of the morphology of gelatin fibers obtained by centrifugal spinning. Differences in the amount of bonding depending on the raw material used and the presence of a cross-linker were analyzed using Fourier transform infrared spectroscopy (FTIR). The overall results showed that chicken gelatin is a suitable alternative to gelatins from traditional sources and can be used for preparing food and pharmaceutical packaging and coatings, fibers, or bioprinting of 3D matrices.

Electrospun Gelatin Scaffolds with Incorporated Antibiotics for Skin Wound Healing.

Recent advances in regenerative medicine provide encouraging strategies to produce artificial skin substitutes. Gelatin scaffolds are successfully used as wound-dressing materials due to their superior properties, such as biocompatibility and the ability to mimic the extracellular matrix of the surrounding environment. In this study, five gelatin combination solutions were prepared and successfully electrospun using an electrospinning technique. After careful screening, the optimal concentration of the most promising combination was selected for further investigation. The obtained scaffolds were crosslinked with 25% glutaraldehyde vapor and characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The incorporation of antibiotic agents such as ciprofloxacin hydrochloride and gentamicin sulfate into gelatin membranes improved the already existing antibacterial properties of antibiotic-free gelatin scaffolds against Pseudomonas aeruginosa and Staphylococcus aureus. Also, the outcomes from the in vivo model study revealed that skin regeneration was significantly accelerated with gelatin/ciprofloxacin scaffold treatment. Moreover, the gelatin nanofibers were found to strongly promote the neoangiogenic process in the in vivo chick embryo chorioallantoic membrane assay. Finally, the combination of gelatin's extracellular matrix and antibacterial agents in the scaffold suggests its potential for effective wound-healing treatments, emphasizing the importance of gelatin scaffolds in tissue engineering.

Pea-like inspired design: Lignin nanospheres-mediated PVA film with high strength, low water evaporation permeability, strong UV resistance and anti-oxidation properties for extending food freshness

The excessive utilization of petroleum-based plastic products has inflicted significant harm upon the ecological and health problems, compelling individuals to continually seek renewable and biodegradable polymer materials as alternatives. Drawing inspiration from the structure of a natural pea pod, a unique interlocking packaging material based on a pea-like structure is obtained via green electrospinning and mild glutaraldehyde (GA) cross-linking method. Herein, polyvinyl alcohol (PVA) serves as a green protective layer encompassing the active lignin nanospheres (LNP) pod, forming a packaging film that prevents LNP migration. The LNP within the fibers can effectively shorten the fiber spacing, and when exposed to the GA vapor, they promote the bonding between neighboring fibers to form a tight interlock structure. Benefiting from the interlocking pea-like structure, the film exhibits excellent tensile strength (3.53 ± 0.02 MPa), wetting strength (1.92 ± 0.05 MPa), and outstanding water vapor barrier properties (3.27 ± 0.3 10−10 gm−1 s−1 Pa−1). Furthermore, the inclusion of LNP endows exceptional water resistance, UV-blocking capabilities, antibacterial and antioxidant properties, which can effectively prolong the storage life of perishable fruits. This eco-logical sustainable design holds tremendous potential in mitigating the burden on the environment, thus making a novel avenue for exploring alternatives to petroleum-derived plastics.

Improvement in the Sustained-Release Performance of Electrospun Zein Nanofibers via Crosslinking Using Glutaraldehyde Vapors.

Volatile active ingredients in biopolymer nanofibers are prone to burst and uncontrolled release. In this study, we used electrospinning and crosslinking to design a new sustained-release active packaging containing zein and eugenol (EU). Vapor-phase glutaraldehyde (GTA) was used as the crosslinker. Characterization of the crosslinked zein nanofibers was conducted via scanning electron microscopy (SEM), mechanical properties, water resistance, and Fourier transform infrared (FT-IR) spectroscopy. It was observed that crosslinked zein nanofibers did not lose their fiber shape, but the diameter of the fibers increased. By increasing the crosslink time, the mechanical properties and water resistance of the crosslinked zein nanofibers were greatly improved. The FT-IR results demonstrated the formation of chemical bonds between free amino groups in zein molecules and aldehyde groups in GTA molecules. EU was added to the zein nanofibers, and the corresponding release behavior in PBS was investigated using the dialysis membrane method. With an increase in crosslink time, the release rate of EU from crosslinked zein nanofibers decreased. This study demonstrates the potential of crosslinking by GTA vapors on the controlled release of the zein encapsulation structure containing EU. Such sustainable-release nanofibers have promising potential for the design of fortified foods or as active and smart food packaging.

TECHNIQUE FOR IMPROVING THE ANALYTICAL CHARACTERISTICS OF BIOSENSORS BASEDON ENZYMES OF THE OXIDASE SUBCLASS

Aim. In this study, the possibility of improving the analytical performance of a monoenzyme biosensor based on the main oxidase pathway by adding catalase to bioselective membranes was increased. Catalase helps strengthen the acid biomembrane, which facilitates the reaction that catalyzes glucose oxidase (GOD). Methods. A standard glucose oxidase conductometric biosensor for increasing glucose was tested and a new bienzyme biosensor with glucose oxidase and catalase was created. To create bioselective membranes, enzymes were immobilized on the electrode surface for additional covalent formation of molecules in glutaraldehyde vapor. Results. An optimal method for stabilizing enzymes and slowing down the biosensor operation depending on the catalase concentration was proposed. The stability of the biosensor preparation procedures and the recognition of the results were assessed. The presented analytical characteristics of a bienzyme biosensor with a monoenzyme based on GOD showed that the addition of catalase provided high efficiency, output of results and linear dynamism of the secret range operation. Conclusion. The proposed method can be used to improve other oxidase-based biosensors.

Improving structural and functional properties of starch-catechin-based green nanofiber mats for active food packaging by electrospinning and crosslinking techniques

The hydrophilic and low mechanical properties limited the application of starch-based films. In this work, a hydrophobic starch-based nanofiber mat was first successfully prepared from aqueous solution at room temperature by using electrospinning and glutaraldehyde (GTA) vapor phase crosslinking techniques for active packaging applications. Catechin (CAT) was immobilized in the nanofibers by electrospinning, resulting in higher thermal stability (Tdmax = 315.23 °C), antioxidant (DPPH scavenging activity = 94.31 ± 2.70 %) and antimicrobial (inhibition zone diameter = 15.6 ± 0.3 mm) of the fibers, which further demonstrated hydrogen bonding and electrostatic interaction between CAT and fibers. Nanofibers after GTA vapor phase crosslinking exhibited enhanced hydrophobicity (water contact angle: 15.6 ± 1.5° → 93.5 ± 2.3°) and mechanical properties (tensile strength: 1.82 ± 0.06 MPa → 7.64 ± 0.24 MPa, elastic modulus: 19.35 ± 0.63 MPa → 45.34 ± 0.51 MPa). The results demonstrated that preparation of starch-based electrospun nanofiber mats in aqueous system at room temperature overcame the challenges of organic solvent pollution and thermosensitive material encapsulation, while GTA vapor phase crosslinking technique improved the hydrophobicity and mechanical properties of nanofiber mats, which facilitated the application of starch-based materials in the field of packaging.

Water‐soluble astaxanthin and silver enriched poly(vinyl alcohol)/silk fibroin crosslinking electrospun nanofiber for wound dressing

AbstractThe aim of this work is to fabricate a novel electrospun poly(vinyl alcohol) (PVA)/silk fibroin (SF) nanofibrous membrane containing astaxanthin (ASTA) and silver (Ag) nanoparticles as potential wound dressing. Since ASTA is typically liposoluble, the bioavailability could be greatly enhanced by improving its hydrophilicity. The antioxidant performance of eletrospun membrane is verified by ABTS radical scavenging assays. The beadless fibers could be fabricated at 16 kV when PVA (12, wt%) is blended with SF (6, wt%). In addition, the membrane is carefully chemically crosslinked by comparing the efforts (i.e., mechanical strength and water resistance) of glutaraldehyde dipping and vapor treatment. The morphology of the electrospun membrane is observed by scanning electron microscopy and optical microscope. The formation of Ag nanoparticles, which provides the membranes antibacterial properties, is also confirmed by energy dispersive spectroscopy and inhibition zone test. Meanwhile, the PVA/SF/ASTA/Ag compound membrane is characterized by Fourier transform infrared spectroscopy, x‐ray diffraction, thermo gravimetric analysis, differential thermal analysis, and water contact angle. The releasing of ASTA is also measured, and kinetic data are adjusted by Higuchi models. Finally, the biocompatibility is confirmed by in vitro cell staining experiments and in vivo rat models.

Patterned thin film enzyme electrodes via spincoating and glutaraldehyde vapor crosslinking: towards scalable fabrication of integrated sensor-on-CMOS devices.

Effective continuous glucose monitoring solutions require consistent sensor performance over the lifetime of the device, a manageable variance between devices, and the capability of high volume, low cost production. Here we present a novel and microfabrication-compatible method of depositing and stabilizing enzyme layers on top of planar electrodes that can aid in the mass production of sensors while also improving their consistency. This work is focused on the fragile biorecognition layer as that has been a critical difficulty in the development of microfabricated sensors. We test this approach with glucose oxidase (GOx) and evaluate the sensor performance with amperometric measurements of in vitro glucose concentrations. Spincoating was used to deposit a uniform enzyme layer across a wafer, which was subsequently immobilized via glutaraldehyde vapor crosslinking and patterned via liftoff. This yielded an approximately 300 nm thick sensing layer which was applied to arrays of microfabricated platinum electrodes built on blank wafers. Taking advantage of their planar array format, measurements were then performed in high-throughput parallel instrumentation. Due to their thin structure, the coated electrodes exhibited subsecond stabilization times after the bias potential was applied. The deposited enzyme layers were measured to provide a sensitivity of 2.3 ± 0.2 μA mM-1 mm-2 with suitable saturation behavior and minimal performance shift observed over extended use. The same methodology was then demonstrated directly on top of wireless CMOS potentiostats to build a monolithic sensor with similar measured performance. This work demonstrates the effectiveness of the combination of spincoating and vapor stabilization processes for wafer scale enzymatic sensor functionalization and the potential for scalable fabrication of monolithic sensor-on-CMOS devices.

Self-assembled electrospun PVA/CMC/PEO composite fiber film material with enhanced dye adsorption performance for wastewater treatment

As society rapidly progresses, environmental issues, including water pollution and ecosystem degradation are steadily worsening. In this work, a novel functional nanofiber composite film based on polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), and polyethylene oxide (PEO) were prepared by using electrospinning technique. The incorporation of PEO facilitated a more concentrated nanofiber diameter distribution. The prepared composite films were further modified with glutaraldehyde vapor to enhance their hydrophobicity and improve pore-making capabilities on the fiber surface. The nanocomposite fiber film, with its simple preparation process, cost-effectiveness, and environmental friendliness, exhibits a promising prospect in addressing environmental challenges. Notably, the designed nanofiber films demonstrated remarkable efficiency in dye adsorption, owing to the high specific surface area of the fibers and the selective binding of active groups on the fiber surface to the dyes. Moreover, they showed good reusability, which is of great significance for adsorbents. Therefore, the obtained composite films from environmentally friendly preparation process has great application potential in wastewater treatment and dye removal.

Fabrication of immobilized xylanase by a novel 3D electrostatic printing as an excellent catalyst for corn straw degradation

Extrusion-based 3D printing has been widely utilized in enzyme immobilization to obtain the desired shape, even though the result is less fine. Here, we report a novel 3D electrostatic printing (3DEP) technology that combines the technologies of electrospinning and 3D printing to manufacture fiber membranes that are finer and uniform and used them for xylanase immobilization. After optimizing the preparation conditions for the 3DEP immobilization carrier, the finer, uniform fiber membranes were printed by using a ratio of 10:1 polyvinyl alcohol (PVA) and chitosan (Cs) under a constant voltage (5 kV) and feed rate (0.001 mm/s). Additionally, 50% glutaraldehyde (GA) vapor was used for cross-linking Cs in order to improve the water insolubility of the support. The 3DEP immobilized xylanase was then prepared by mixing xylanase and the printed materials. The resulting immobilized xylanase exhibited excellent stability, with over 95% of enzyme activity following storage for 28 days, and 53% xylan conversion was still retained after reuse over 8 batches. Finally, the 3DEP immobilized xylanase featured good catalytic efficiency in degrading corn straw. Collectively, the results of this study show that 3DEP offered a finer carrier manufacturing technology and could improve the catalytic efficiency of the immobilized enzyme.

Thermo-mechanical performance of nanostructured electrospun composites produced from poly(vinyl alcohol) and cellulosic compounds for potential uses as wound dressings

The purpose of this research was to analyze the morphology, thermal and mechanical properties of poly(vinyl alcohol) (PVA)-based electrospun mats reinforced with cellulose acetate (CA) or cellulose nanocrystalline (CNC) for potential applications in wound dressings. Bead-free and water-stable electrospun nanofibers made of blends of PVA and CA or CNC were successfully produced and crosslinked with glutaraldehyde vapor. Crosslinking slightly increased the nanofibers' diameters in order of 43 and 13% for 80/20 PVA/CA and PVA/CNC electrospun mats, respectively, while maintaining their bead-free morphology. Thermogravimetry (TGA) and differential scanning calorimetry (DSC) evaluations were employed to determine the miscibility and the thermal response of the uncrosslinked and crosslinked mats, reporting a reduction in mass loss upon addition of CA and CNC and upon crosslinking process. Polymers' powder and mats (before and after crosslinking) crystallinity was assessed by X-ray diffraction analysis (XRD). Crosslinked mats experienced a slight reduction in crystallinity compared to the uncrosslinked. Static and dynamic tensile strength tests revealed that CA and CNC doped mats enhanced the Young's modulus and lowered deformation at failure compared to pristine PVA electrospun mats. Data from storage modulus (E′) demonstrated the strength of the physical interactions formed between PVA and the cellulosic derivatives (either before and after crosslinking), highlighting the stiffness of CA (231.58 MPa for the 80/20 mat) and, particularly, CNC (742.04 MPa for the 80/20 mat). This research uncovered important information concerning the chemical and physical relation between polymeric matrices and additives, essential for the proper selection of materials for wound dressings production.

Electrospinning of poly(vinyl alcohol) and poly(vinyl alcohol)/tannin solutions: A critical viewpoint about crosslinking

Poly(vinyl alcohol) (PVA) is a hydrophilic and cytocompatible polymer used in biomedical, pharmaceutical, food, and environmental applications. However, the PVA aqueous solubility restricts its direct application. To overcome this disadvantage, PVA chains can be chemically crosslinked to impart stability and durability to the engineered materials. This work presents PVA/Tanfloc (PVA/TN) electrospun fibers for the first time. TN is an amino-functionalized polyphenolic tannin derivative. PVA/TN materials were created from PVA/TN blends in water (W)/acetic acid (HAc) (99/1 v/v) and W/formic acid (FA) (50/50 v/v) mixtures. FA and glutaraldehyde (GA) were evaluated as crosslinkers for the electrospun fibers. GA vapor was also tested as a crosslinker. PVA and PVA/TN materials (before and after crosslinking) were characterized by infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The as-prepared PVA/TN fibers quickly dissolved in ethanol and water but not in acetone. Fiber durability increased in acetone when the TN content was at least 20 wt%. PVA/TN fibers were crosslinked in acetone containing GA (1.0 wt%) and HAc (1.0 % v/v). However, GA-crosslinked fibers had no stability in water after washing. The stability of PVA-based electrospun fibers after GA crosslinking has not been previously reported in the literature. PVA/TN fibers were also crosslinked by thermal treatment. This strategy maintained the fiber structure after water immersion over 15 days. This study presents a critical viewpoint concerning strategies to crosslink PVA-based fibers, focusing on fiber durability and stability after crosslinking. The thermal treatment is by far the best method to crosslink PVA-based fibers because it can maintain fiber morphology, promoting aqueous durability.

Fabrication of Glutaraldehyde Vapor Treated PVA/SA/GO/ZnO Electrospun Nanofibers with High Liquid Absorbability for Antimicrobial of Staphylococcus aureus.

In this study, we aim to develop organic-inorganic hybrid nanofibers containing high moisture retention and good mechanical performance as an antimicrobial dressing platform. The main theme of this work focuses on several technical tasks including (a) the electrospinning process (ESP) to produce organic polyvinyl alcohol/sodium alginate (PVA/SA) nanofibers with an excellent diameter uniformity and fibrous orientation, (b) the fabrication of inorganic nanoparticles (NPs) as graphene oxide (GO) and ZnO NPs to be added to PVA/SA nanofibers for enhancement of the mechanical properties and an antibacterial function to Staphylococcus aureus (S. aureus), and then (c) the crosslinking process for PVA/SA/GO/ZnO hybrid nanofibers in glutaraldehyde (GA) vapor atmosphere to improve the hydrophilicity and moisture absorption of specimens. Our results clearly indicate that the uniformity nanofiber with 7 wt% PVA and 2 wt% SA condition demonstrates 199 ± 22 nm in diameter using an electrospinning precursor solution of 355 cP in viscosity by the ESP process. Moreover, the mechanical strength of nanofibers was enhanced by 17% after the handling of a 0.5 wt% GO nanoparticles addition. Significantly, the morphology and size of ZnO NPs can be affected by NaOH concentration, where 1 M NaOH was used in the synthesis of 23 nm ZnO NPs corresponding to effective inhibition of S. aureus strains. The PVA/SA/GO/ZnO mixture successfully performed an antibacterial ability with an 8 mm inhibition zone in S. aureus strains. Furthermore, the GA vapor as a crosslinking agent acting on PVA/SA/GO/ZnO nanofiber provided both swelling behavior and structural stability performance. The swelling ratio increased up to 1.406%, and the mechanical strength was 1.87 MPa after 48 h of GA vapor treatment. Finally, we successfully synthesized the hybrid nanofibers of GA-treated PVA/SA/GO/ZnO accompanied with high moisturizing, biocompatibility, and great mechanical properties, which will be a novel multi-functional candidate for wound dressing composites for patients receiving surgical operations and first aid treatments.

Controlled Release of Gentamicin from Electrospun Poly(Vinyl Alcohol)/Gelatin Nanofibers: The Effect of Crosslinking Time Using Glutaraldehyde Vapor

AbstractIn this study, polyvinyl alcohol (PVA), gelatin (GEL) and gentamicin (GEN) were used and 13PVA/0.5GEL/GEN nanofibers were fabricated with the electrospinning method. These nanofibers were crosslinked chemically with glutaraldehyde (GA) at different time intervals (2, 3, 4, 5, 5.5 and 6 h) to observe the crosslinking effect on the properties of the nanofibers. Morphological analysis reported that as the crosslinking time increased, the nanofiber diameters also increased from 369.26 nm (non‐crosslinked) to 447.72 nm (6 h/crosslinking), respectively. The thermal characterization results demonstrated that crosslinking with different times noticeably shifted the thermal points.The tensile testing results proved that application of crosslinking enhanced the mechanical strength of the nanofibers from 3.31 MPa (non‐crosslinked) to 5.8 MPa (5.5 h/crosslinking), respectively. The GEN release profiles from the nanofibers showed similar behaviors under crosslinking and indicated that the crosslinking time did not have a significant effect on the amount of the GEN released.

Evaluating neem gum-polyvinyl alcohol (NGP-PVA) blend nanofiber mat as a novel platform for wound healing in murine model

Modern-day treatment demands scarless wound healing utilizing scaffolds in the form of nanofiber mats which are tissue and environment-friendly. Neem gum polysaccharide (NGP) in conjugation with Polyvinyl alcohol (PVA) in the form of nanofibers exhibits antimicrobial properties mimicking extracellular matrix for tissue growth. Different grades of nanofibers mats (NFM) were prepared by combining different ratios of NGP and PVA which were later crosslinked using glutaraldehyde vapors (25 % w/v in 0.5 M HCl), and optimized grade G14 exhibited maximum tensile strength with smooth surface morphology, hemocompatible properties, in-vitro biodegradability and antimicrobial action against S. aureus &E. coli. G14 was analytically characterized using different analytical techniques viz. Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), which indicated polymer-polymer compatibility. The surface hydrophobicity as detected using Optical contact angle (OCA) confirmed the hydrophobicity of NFM with increased glutaraldehyde vapor for crosslinking when compared to non-crosslinked NFM. Histopathology slides indicated G14 CL-NFM accelerated the wound healing in mice with dense collagen and fibroblasts when compared to control mice suggesting the tissue engineering potential of the prepared device.

Improving the hydrophobicity and mechanical properties of starch nanofibrous films by electrospinning and cross-linking for food packaging applications

Many efforts have been devoted to developing starch-based films as an alternative to non-degradable petroleum-based plastic food packaging. However, the application of starch-based films still faces serious challenges due to their water sensitivity and poor mechanical properties. In this work, a simple route was proposed to develop crosslinked starch nanofibrous films (C-SNFs) through electrospinning of starch solution, followed by crosslinking in glutaraldehyde (GTA) vapor. The effect of electrospinning parameters such as starch concentration (20–30 wt%), applied voltage (15–25 kV), and collecting distance (10–20 cm) on fiber morphology was studied. Compared with solution-cast starch films, electrospun starch nanofibrous films (SNFs) showed superior flexibility but poor mechanical strength and water sensitivity. After GTA crosslinking post-treatment, the tensile strength and water contact angle (WCA) of SNFs could be enhanced up to ∼9.65 MPa and ∼94.3°, respectively. Results from this work could provide a facile route to fabricate starch-based film materials that showed a promising potential application in the food packaging field.

Influence of crosslinking on the drug release of PLLA/gelatin nonwovens

Abstract Electrospun fibers based on synthetic and natural polymers represent a promising approach in order to mimic the mechanical stability and the required cell-polymer interaction of the natural extracellular matrix (ECM), . In this biomedical context, the biodegradable medical grade poly-llactide (PLLA) and the natural gelatin are already well established. However, to obtain a stabilized structured PLLA/gelatin blend, crosslinking of gelatin is required. In this study, the influence of the post processed crosslinking via Glutaraldehyde (GTA) vapor and GTA solution on the morphological and physicochemical properties of the blend, as well as on the in vitrorelease of previously incorporated dexamethasone (DMS), was investigated. The addition of gelatin decreased the fiber diameter and increased the surface hydrophilicity, which is furthermore unaffected by the crosslinking process. The in vitrorelease of DMS was decisively changed by both, the addition of gelatin and the subsequent crosslinking processes. For all modified samples, a very rapid burst release of DMS was detected within the first 24 h, which is crucial for biomedical applications such as tumor therapy.

Kollajen/Jelatin/Bal Esaslı Çift Katmanlı Doku İskelesi Üretimi ve Karakterizasyonu

In this project, a porous tissue scaffold composed of collagen/gelatin, which are natural, biocompatible, and biodegradable polymers, was fabricated by lyophilization, then a nanofibrous gelatin/polyethylene oxide (PEO)/honey blend was accumulated onto this layer via the electro-spinning process. The tissue scaffold was cross-linked by treating with glutaraldehyde vapor followed by EDC/NHS reagents. For the characterization, Fourier Transformed Infrared (FTIR) spectroscopy, Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), pore size distribution analysis, and aqueous degradation tests were performed. While the lyophilized layer was fabricated by 1:1 (w/w) collagen/gelatin mixture, the top layer was electro-spun onto this layer by selecting the most appropriate blend ratio (2:2:2 w/w, %6 w/v total material). The lyophilized scaffold layer had a wide pore size distribution in the 5−200 µm range. After the cross-linking, pore size distribution became more homogenous (concentrating around 30−40 µm). According to SEM analysis, a uniform fiber size distribution (Dave = 423 ± 85 nm) was obtained and after the cross-linking and rinsing processes a slight fiber fusion occurred. Regarding the TGA and degradation results, the scaffold robustness increased after the cross-linking. Overall, the developed tissue scaffold with its stable, porous and fibrous form could be a suitable candidate for different tissue engineering applications.