In particular, the tip of the needle is usually attached to the positive terminal of the electric field [24]. Under these conditions, the increase in tension causes the formation of a Taylor cone in the tip of the needle [25].
Synthetic polymers .1 Polylactic acid (PLA)
This biopolymer is known as one of the other polysaccharides commercially produced from brown algae or some bacteria, such as Azotobacter chroococcum, Azotobacter vinelandii and some species of Pseudomonas [121, 123]. PEG is known as one of the most popular synthetic polymers in tissue engineering applications and can promote cellular adhesion and enhance cell-cell signaling due to its hydrophilic properties and interactions with the chains of polysaccharides or peptides [51, 136].
Copolymer/hybrid polymers
Application of electrospun polymers in tissue engineering
One of the other applications of electrospun scaffolds is related to the design of calcified extracellular matrices. They found that electrospun scaffolds based on poly (glycerol sebacate) elastomer and poly (lactic acid) can induce neovascularization without the inflammatory reactions and support cardiomyocyte development [149].
Challenges and resolutions of the electrospinning process
Conclusion
Modification of electrospun scaffold properties by silver nanoparticle incorporation: Evaluation for vascular tissue engineering. Design of functional electrospun scaffolds based on poly(glycerol sebacate) elastomer and poly(lactic acid) for cardiac tissue engineering.
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Introduction
Traditionally, materials such as plastic, glass, metal, paper and cardboard have been used to develop food packages [1, 2]. However, interest in polymeric materials has increased tremendously as they have several advantages such as low cost, light weight and good mechanical, barrier and optical properties [3, 4]. In this context, the packaging field has concentrated in recent decades on the development of materials that can maintain or improve the properties of food and thereby extend its shelf life.
Thus, Figure 1 shows a comparison between the number of indexed articles on "Food Packaging" and "Active Food Packaging" published in the Web of Science (WOS) database. This figure shows the growing interest in the research field of food packaging over the past two decades, demonstrating that active food packaging has been particularly leading in the past 5 years compared to published research on traditional food packaging.
Active food packaging technology 1 Definition
- Formats and technologies
The design of active packaging systems is mainly focused on the characteristics of the active compound and the packaged food. Immobilization of the active compound in the inner layer of the packaging material through ionic or covalent bonds. In this work, fresh beef was packaged in commercial trays with modified atmosphere (70% O2 + 30% CO2), and active labels were placed on the top of the tray to protect the food.
On the other hand, molding technology has also been a useful tool for manufacturing active food packaging systems. In this context, Sooch and Mann developed an active package of gelatin and copper nanoparticles doped with titanium dioxide. Likewise, multilayer materials have also been developed for active packaging of meat products through coating technology.
On the other hand, non-traditional techniques such as carbon dioxide supercritical impregnation and atomic layer deposition (ALD) have also been used to develop active materials. In this context, nanotubes and spherical particles of titanium dioxide (TiO2) and zinc oxide (ZnO) have been produced by this combination [17-19]. As technology has advanced, in the last decade a new technique known as electrospinning has been used to develop polymeric materials that play a fundamental role behind the active packaging system.
Electrospinning
- Influence of the properties of the polymeric solution .1 Polymer concentration
- Influence of operational parameters .1 Flow rate
- Active electrospun materials
- Influence of active compounds during electrospinning process
- Application of active electrospun materials on food packaging
This fact, in turn, can cause a decrease in the diameter of the fibers and the presence of beads in their surface. A recent study proved the decrease of the diameter and the presence of beads in polycaprolactone (PCL) nanofibers when the polymeric concentration decreased from 13 to 8 wt% [21]. The increase in electrical conductivity in the polymeric solution is mainly related to the increase in the concentration of the polymer, which favors the electrospinning process and the formation of the fibers.
Like the studies mentioned above, the active ingredient increased the viscosity of the solution and affected the fiber diameter [31]. On the other hand, the effect of the inclusion of plant extracts on the viscosity of polymeric solutions has produced different behaviors. Likewise, an increase in the concentration of jaboticaba peel extract in a zein solution decreased its viscosity and fiber diameter [35].
In this case, the addition of the extract reduced the surface tension without affecting the morphology of the fibers [34]. Despite this, the morphology and the diameter of the fibers showed different trends. Like the above study, the active compound significantly increased the electrical conductivity of the polymeric solution.
Conclusions
In this sense, the latest developments regarding active wrapping films, pouches, films and pouches obtained through electrospinning have shown their potential application for active food packaging (Table 2). In both cases, weight loss of vegetables was reduced, and therefore, their shelf life was extended [62, 63]. On the other hand, although this technique represents a current low level of technological readiness in the area of food packaging, the interest and projection of this technology to be applied is growing exponentially.
Therefore, electrospun mats could be proposed as the new generation of materials to be used in the active food packaging. Supercritical impregnation of cinnamic aldehyde into polylactic acid as a route to develop antibacterial food packaging materials. Carvacrol-filled electrospun fibrous films from zein and poly(lactic acid) for active food packaging.
Biodegradable active food packaging structures based on crosslinked electrospun polyvinyl alcohol hybrid fibers containing essential oils and their application in the preservation of chicken breast fillets. Electrospun pullulan/PVA nanofibers integrated with thymol-loaded metal organic porphyrin framework for antibacterial food packaging. Development of electrospun films enriched with ethyl lauroyl arginate as novel antimicrobial food packaging materials for the preservation of fresh strawberries.
Parameters affecting electrospinning process
- Solution parameters
- Processing variables
- Environmental conditions
As the viscosity increases, the formation of the bead structure decreases and more regular nanofibers are obtained [9]. Therefore, factors that affect solution viscosity also affect the electrospinning process and the resulting fibers. The molecular weight of the polymer used in the electrospinning process has a direct effect on properties such as viscosity, surface tension, and conductivity, and this interaction determines nanofiber formation.
The length of the polymer chain will determine the amount of entanglement of the polymer chains in the solvent [1]. The decrease in the surface tension of the solution ensures the formation of finer and smoother fibers and a problem-free electrospinning process [4]. As the amount of applied stress increases, the diameters of the obtained nanofibers will decrease [4].
The reduction in occlusion is due to less exposure of the solution to the atmosphere during electrospinning. The decrease in the inner diameter of the hole causes a decrease in the diameter of the nanofibers. Pressure changes in the electrospinning process make it difficult to ensure the stability of the drawing process.
Herbal extracts used to obtain nanofibers by electrospinning method Reasons such as health problems, population density, environmental pollution,
Application areas of nanofibers obtained from plant extracts by electrospinning method
- Wound healing
- Tissue engineering
- Drug delivery systems
Herbal extracts used to obtain nanofibers by electrospinning method Reasons such as health problems, population density, environmental pollution,. Compared to other wound dressings, nanofiber wound dressing has advantages such as hemostasis, high porosity, good fluid absorption capacity, small pore sizes, and large surface area [4]. The use of herbal extracts as wound dressing can nourish the wound site with healing properties such as antimicrobial, anti-inflammatory, analgesic and tissue regeneration [30].
Therefore, dissolution of plant extracts almost never occurs in polymer carriers such as capsules, nanofiber mats, and casting films containing herbal drugs. Electrospinning has a high potential application in many areas of tissue engineering such as vascular, bone, neural and tendon/ligament. Nanofibers in tissue engineering should have such as biocompatible, biodegradable (with an acceptable lifetime), tissue-appropriate degradation rate, tissue-appropriate mechanical (strength, stiffness and modulus) and structural (pore size, shape and structure) properties and sterilization [45].
While drug delivery is generally associated with the delivery of therapeutic agents for the treatment of certain disease states such as cancer, the delivery systems for tissue engineering applications may also apply to the delivery of bioactive agents such as proteins and DNA [5]. In nanofiber applications such as wound dressings or artificial leather, the local controlled release of antibiotics can aid the healing process. There are different applications such as the design of coaxial nanofibers using olive leaf extract as a bioactive agent [25], the production of nanofiber membranes containing aloe vera [48], the use of nanofibers prepared with the bark of.
Conclusion
Nanofiber drug delivery systems containing herbal extracts are expected to increase therapeutic efficacy, reduce toxicity, and ensure patient compatibility by delivering drugs to the affected area at a controlled rate for a defined period. Keratin esaslı suyshetlerin elektročekim meddaşıle elde ızılış, karakterizaçãou ve gaz sorpsiyon ışının incelensemi, [doctoral thesis]. Preparation and performance evaluations of electrospun poly(e-caprolactone), poly(lactic acid) and their hybrid (50/50) nanofibrous mats containing thymol as herbal medicine for effective wound healing.
Influence of solvents on the formation of uniform ultrathin poly(vinylpyrrolidone) nanofibers by electrospinning. Effects of solution and polyelectrolyte properties on electrospinning of poly(ethylene oxide) ultrafine fibers. Electrospinning of poly(Hydroxybutyrate-co-. hydroxyvalerate) fibrous scaffolds for tissue engineering applications: Effects of electrospinning parameters and solution properties.
Green electrospun grape seed extract-filled silk fibroin nanofibrous mats with excellent cytocompatibility and antioxidant effect. Morphology, drug release, antibacterial, cell proliferation and histology studies of chamomile loaded wound dressing mats based on electrospun nanofibrous poly. Electrospun poly (L-lactic acid) fiber mats containing crude Garcinia mangostana extracts for use as wound dressings.
