An ultra-low-cost and adjustable in-house electrospinning machine to produce PVA nanofiber

Recent progress in biopolymer-based electrospun nanofibers and their potential biomedical applications: A review

Tissue engineering offers an alternative approach to developing biological substitutes that restore, maintain, or enhance tissue functionality by integrating principles from medicine, biology, and engineering. In this context, biopolymer-based electrospun nanofibers have emerged as attractive platforms due to their superior physicochemical properties, including excellent biocompatibility, non-toxicity, and desirable biodegradability, compared to synthetic polymers. Considerable efforts have been dedicated to developing suitable substitutes for various biomedical applications, with electrospinning receiving considerable attention as a versatile technique for fabricating nanofibrous platforms. While the applications of biopolymer-based electrospun nanofibers in the biomedical field have been previously reviewed, recent advancements in the electrospinning technique and its specific applications in areas such as bone regeneration, wound healing, drug delivery, and protein/peptide delivery remain underexplored from a material science perspective. This work systematically highlights the effects of biopolymers and critical parameters, including polymer molecular weight, viscosity, applied voltage, flow rate, and tip-to-collector distance, on the resulting nanofiber properties. The selection criteria for different biopolymers tailored to desired biomedical applications are also discussed. Additionally, the challenges and limitations associated with biopolymer-based electrospun nanofibers, alongside future perspectives for advancing their biomedical applications, are rationally analyzed.

Open-source cold and hot scientific sheet press for investigating polymer-based material properties

To produce samples for both material testing and molded sheets/parts, this article details an open-source scientific cold and hot press design. It consists of two independent and modular upper and lower plate (929 cm2) assemblies each containing four 125 W insulated steel strip heaters. The steel housing for these heaters is entirely modular and designed for ease of manufacture, assembly, and customization. This system allows a researcher with access to a hydraulic press to repurpose existing equipment into a multipurpose hot and cold press, or if an independent machine is warranted, an additional welded support frame and commercially available bottle jack offer standalone operation. By utilizing this small-scale hot press either in conjunction with a hydraulic press or on its own, samples can be produced to determine the critical material properties of any polymer, composite, or polymer blend. A series of modular molds allow for the rapid production of flat sheet stock and solid testing samples adhering to the ASTM D695 standard for rigid plastics tested in compression and ASTM D638 standard for testing plastics in tension. The sheet mold offers the user the ability to produce stock sheets that can be cut and assembled into 2.5-D applications with post processing.

Personalised Medicine and the Potential Role of Electrospinning for Targeted Immunotherapeutics in Head and Neck Cancer

Advanced head and neck cancer (HNC) is functionally and aesthetically destructive, and despite significant advances in therapy, overall survival is poor, financial toxicity is high, and treatment commonly exacerbates tissue damage. Although response and durability concerns remain, antibody-based immunotherapies have heralded a paradigm shift in systemic treatment. To overcome limitations associated with antibody-based immunotherapies, exploration into de novo and repurposed small molecule immunotherapies is expanding at a rapid rate. Small molecule immunotherapies also have the capacity for chelation to biodegradable, bioadherent, electrospun scaffolds. This article focuses on the novel concept of targeted, sustained release immunotherapies and their potential to improve outcomes in poorly accessible and risk for positive margin HNC cases.

Fabricating orientated nanofibrous meshes with a bespoke ultra-cost-effective electrospinning machine

Electrospinning's production method has been streamlined and perfected because to advancements in technology and increased demand. While working with electrospun fibers, it is crucial to ensure that they are collected in the correct orientation. Electrospun fibers can be either aligned or random. In contrast to randomly oriented fibers, all aligned ones will point in the same direction. Our results show that a low-cost, tailored electrospinning device can achieve equivalent performance to that of a commercially available system. High voltage (up to 36 kV) and nanofiber orientation adjustments are now being made to the proposed device. A high-voltage direct-current electrical power supply that is custom-built per order and wired by hand. Two specialized collectors, one portable and manufactured from conductive material for random nanofibers, and the other an inexpensive rotational drum collector for aligned nanofibers, have been developed to allow for precise orientation control. By applying Image J software to scanning electron micrographs, we were able to determine the average diameter and orientation of the fibers produced by the electrospinning apparatus, demonstrating its potential to produce nanoscale directed fibers. Because of this research, it's possible that schools will be able to afford an electrospinning system at a price far lower than the current market price.

Development of dual-functional core-shell electrospun mats with controlled release of anti-inflammatory and anti-bacterial agents for the treatment of corneal alkali burn injuries

In this study, a novel dual-drug carrier for the co-administration of an anti-inflammatory and antibiotic agent consisting of core-shell nanofibers for the treatment of cornea alkali burns was designed. The core-shell nanofibers were prepared via coaxial electrospinning of curcumin-loaded silk fibroin as the core and vancomycin-loaded chitosan/polyvinyl alcohol (PVA) as the shell. Electron microscopy (SEM and TEM) images confirmed the preparation of smooth, bead-free, and continuous fibers that formed clear core-shell structures. For further studies, nanofiber mats were cross-linked by heat treatment to avoid rapid disintegration in water and improve both mechanical properties and drug release. The release profile of curcumin and vancomycin indicated an initial burst release, continued by the extended release of both drugs within 72 hours. Rabbit corneal cells demonstrated high rates of proliferation when evaluated using a cell metabolism assay. Finally, the therapeutic efficiency of core/shell nanofibers in healing cornea alkali burn was studied by microscopic and macroscopic observation, fluorescence staining, and hematoxylin-eosin assay on rabbit eyes. The anti-inflammatory activity of fabricated fibers was evaluated by enzyme-linked immunosorbent assay and Immunofluorescence analysis. In conclusion, using a robust array of in vitro and in vivo experiments this study demonstrated the ability of the dual-drug carriers to promote corneal re-epithelialization, minimize inflammation, and inhibit corneal neovascularization. Since these parameters are critical to the healing of corneal wounds from alkali burns, we suggest that this discovery represents a promising future therapeutic agent that warrants further study in humans.

Thermo-mechanical characterization of electrospun polyurethane/carbon-nanotubes nanofibers: a comparative study

Creating ultrathin, mountable fibers from a wide range of polymeric functional materials has made electrospinning an adequate approach to producing highly flexible and elastic materials. In this paper, electrospinning was utilized to produce thermoplastic polyurethane (TPU) nanofibrous membranes for the purpose of studying their thermal and mechanical properties. Towards a study of the effects of fiber orientation and multi-walled carbon nanotubes (MWCNTs) as a filler on both mechanical and thermal characteristics of electrospun TPU mats, an experimental comparison was held between unidirectional and randomly aligned TPU and TPU/MWCNTs nanofibrous structures. The incorporation of MWCNTs into randomly oriented TPU nanofibers resulted in a significant increase in Young's modulus (E), from 3.9 to 7.5 MPa. On the other hand, for unidirectionally spun fibers, Young's modulus increased from 17.1 to 18.4 MPa upon the addition of MWCNTs. However, dynamic mechanical analysis revealed a different behavior. The randomly oriented specimens exhibited a storage modulus with a significant increase from 180 to 614 MPa for TPU and TPU/MWCNTs mats, respectively, and a slight increase from 119 to 143 MPa for unidirectional TPU and TPU/MWCNTs mats, respectively. Meanwhile, the loss modulus increased with the addition of MWCNTs from 15.7 to 58.9 MPa and from 6.4 to 12 MPa for the random and aligned fibers, respectively. The glass transition values for all the mats fell in the temperature range of - 60 to - 20 °C. The thermal degradation of the membranes was not significantly affected by the addition of MWCNTs, indicating that the mixing of the two constituents did not change the TPU's polymer structure and that the TPU/MWCNTs nanocomposite exhibited stable thermal degradation properties.

A versatile hot melt centrifugal spinning apparatus for thermoplastic microfibres production

The centrifugal spinning (CS) method could address common issues such as low production rate and high energy consumption in the industry of nonwoven textile fabrication. Similarly to cotton candy production, the high-speed rotating reservoir extrudes melt or solvent-based polymer from orifices to produce fibres. Using polymer melt avoids solvent elimination and toxicity, but the process is more difficult. Thus, a versatile lab-scale hot melt spinneret with the ability to pour pellets inside continuously to expand our knowledge of the CS method and investigating different extrusion geometries such as nozzlefree is developed. Among the controllable parameters are, the spinneret heating temperature (up to 300°C), its two interchangeable 3D printer nozzles. An Arduino code is used to stabilize the temperature. The system performance is investigated with polypropylene and polylactide. The results show that fibres under 15 μm in diameter are produced. This work is licensed under CC BY-NC 4.0. To view a copy of this license, visithttp://creativecommons.org/licenses/by-nc/4.0/.