Tailored binary polymer system PCL-PEO for advanced biomedical applications: Optimization, characterization and in vitro analysis

Combining a hydrophobic polymer such as polycaprolactone (PCL) with a hydrophilic polymer polyethylene oxide (PEO) in a binary polymer system can enable a range of novel applications in biomedical engineering by permitting exceptional therapeutic release, antimicrobial possibilities, and heterogeneous tissue engineering scaffolds. In this work, both PCL and PEO were dissolved in chloroform at 15 w/v % at six different ratios to prepare binary polymer solutions. The rheological properties of the singular and binary polymer solutions were measured, and fibers were spun using pressurized gyration. The fiber morphologies of the prepared materials were studied using scanning electron microscopy (SEM). By immersing samples in deionized water, binary polymeric fibers with varying swelling behaviors were developed and analyzed using optical microscopy. The results were used to identify an optimum PCL:PEO binary mixture in chloroform. Chemical compositions of singular/binary polymer composites loaded with ibuprofen (IBP) were characterized by Fourier-transform infrared spectroscopy (FTIR) and thermal analysis was examined using differential scanning calorimetry (DSC). In vitro studies on PEO–IBP exhibited an instant release rate of 90 % in 40 s, whereas PCL–IBP and PCL:PEO–IBP revealed a sustained release of 87–96 % in 72 h, respectively. The results were used to discuss the potential use of binary polymer systems in biomedical applications

Optimised release of tetracycline hydrochloride from core-sheath fibres produced by pressurised gyration

In recent years, there has been a surge of interest in the design, processing, and use of core-sheath fibres, especially in the production of wound healing bandages and drug delivery. In this research, a novel core-sheath pressurised gyration technique was utilised to create antibacterial fibre patches (tetracycline hydrochloride, TEHCL) using polyvinyl pyrrolidone (PVP) and polycaprolactone (PCL). Antibiotic patches showed uniform fibres with a porous surface giving rise to a biphasic delivery system, which provided an initial burst of 30–48% drug release in the first 24 h followed by a constant rate of release throughout the course of 168 h, suitable for wound-dressings application. The effect of operating parameters on fibre morphology, the influence of the coresheath structure and drug loading as well as a mathematical modelling was investigated and analysed. Fouriertransform infrared spectroscopy, and differential scanning calorimetry results demonstrated successful TEHCL encapsulation as well as the presence of both polymers in the core-sheath fibres. The surface morphology of the fibres was studied using scanning electron microscopy and the core-sheath structure was verified using confocal scanning microscopy. Therefore, the core-sheath pressurised gyration method offers an exciting chance to customise fibre patches in a hybrid polymeric system. These advancements are crucial in the world of healthcare to meet demands where antibacterial dressings cannot be produced rapidly or when a personalised approach is necessary

Cleaner and Sustainable Production of Core–Sheath Polymer Fibres

The amalgamation of sustainable practises throughout the fabrication process with advanced material engineering holds promise not only for eco-conscious manufacturing but also for promoting technological advancements in versatile material design and application. Moreover, technological innovation serves as a catalyst for sustainability initiatives, driving innovation and enabling the adoption of greener practises across industries. This study investigates redefining the production protocol of pressure spinning to produce core–sheath polymer fibres, deepening sustainable practises. It aims to explore innovative approaches such as modifying spinning parameters, optimising polymer solvent configurations and understanding fluid behaviour to curtail material wastage and maintain minimal energy consumption without compromising production efficiency. Utilising Polyvinylpyrrolidone (PVP) for the core and Polyethylene oxide (PEO) for the sheath, production rates of up to 64 g/h were achieved with a fibre diameter range of 3.2 ± 1.7 µm to 4.6 ± 2.0 µm. Energy consumption per mass of fibres produced showed a decreasing trend overall with increasing applied gas pressure. These findings highlight the potential for the efficient and scalable production of core–sheath fibres with applications in various advanced materials fields

System among the corticosteroids: specificity and molecular dynamics.

Fil: Brookes, Jennifer C.. University College London; Estados UnidosFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Harker, Anthony H.. University College London; Estados UnidosFil: Stoneham, A. Marshall. University College London; Estados UnidosFil: Vinson, Gavin P.. Queen Mary University of London; Reino Unid

A Portable Device for the Generation of Drug-Loaded Three-Compartmental Fibers Containing Metronidazole and Iodine for Topical Application

The use of combination therapies for the treatment of a range of conditions is now well established, with the component drugs usually being delivered either as distinct medicaments or combination products that contain physical mixes of the two active ingredients. There is, however, a compelling argument for the development of compartmentalised systems whereby the release, stability and incorporation environment of the different drugs may be tailored. Here we outline the development of polymeric fine fiber systems whereby two drugs used for the treatment of wounds may be separately incorporated. Fibers were delivered using a newly developed handheld electrospinning device that allows treatment at the site of need. Crucially, the delivery system is portable and may be used for the administration of drug-loaded fibers directly into the wound in situ, thereby potentially allowing domiciliary or site-of-trauma administration. The three-layered fiber developed in this study has polyethylene glycol as the outermost layer, serving as a structural support for the inner layers. The inner layers comprised iodine complexed with polyvinylpyrrolidone (PVP) and metronidazole dispersed in polycaprolactone (PCL) as a slow release core. The systems were characterized in terms of structure and architecture using scanning electron microscopy, transmission electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy and diffractometry. As antibacterial creams are still used for managing infected wounds, the performance of our trilayered fiber was studied in comparison with creams containing similar active drugs. Drug release was measured by UV analysis, while antimicrobial efficiency was measured using agar diffusion and suspension methods. It was found that the trilayered systems, averaging 3.16 µm in diameter, released more drug over the study period and were confirmed by the microbacterial studies to be more effective against P. aeruginosa, a bacterium commonly implicated in infected wounds. Overall, the portable system has been shown to be capable of not only incorporating the two drugs in distinct layers but also of delivering adequate amounts of drugs for a more effective antibacterial activity. The portability of the device and its ability to generate distinct layers of multiple active ingredients make it promising for further development for wound healing applications in terms of both practical applicability and antimicrobial efficacy

Generating Lifetime-Enhanced Microbubbles by Decorating Shells with Silicon Quantum Nano-Dots Using a 3-Series T-Junction Microfluidic Device

Long-term stability of microbubbles is crucial to their effectiveness. Using a new microfluidic device connecting three T-junction channels of 100 μm in series, stable monodisperse SiQD-loaded bovine serum albumin (BSA) protein microbubbles down to 22.8 ± 1.4 μm in diameter were generated. Fluorescence microscopy confirmed the integration of SiQD on the microbubble surface, which retained the same morphology as those without SiQD. The microbubble diameter and stability in air were manipulated through appropriate selection of T-junction numbers, capillary diameter, liquid flow rate, and BSA and SiQD concentrations. A predictive computational model was developed from the experimental data, and the number of T-junctions was incorporated into this model as one of the variables. It was illustrated that the diameter of the monodisperse microbubbles generated can be tailored by combining up to three T-junctions in series, while the operating parameters were kept constant. Computational modeling of microbubble diameter and stability agreed with experimental data. The lifetime of microbubbles increased with increasing T-junction number and higher concentrations of BSA and SiQD. The present research sheds light on a potential new route employing SiQD and triple T-junctions to form stable, monodisperse, multi-layered, and well-characterized protein and quantum dot-loaded protein microbubbles with enhanced stability for the first time

Proof-of-Concept Assessment of a Photofission-Based Interrogation System for the Detection of Shielded Nuclear Material

A photonuclear interrogation method was experimentally assessed for the detection of shielded nuclear materials. Proof-of-Concept assessment was performed at the Los Alamos National Laboratory (LANL) TA-18 facility and used the INEEL VARITRON electron accelerator. Experiments were performed to assess and characterize the delayed neutron emission responses for different nuclear materials with various shield configurations using three ''nominal'' electron beam energies; 8-, 10-, and 11-MeV. With the exception of highly enriched uranium (HEU), the nuclear materials assessed represent material types commonly encountered in commerce. The specific nuclear materials studied include a solid 4.8-kg HEU sphere, a 5-kg multiple-object, depleted uranium (DU) [uranium with about 0.2% enrichment with U-235] target, and two 11-kg thorium disks. The shield materials selected include polyethylene, borated-polyethylene, and lead. Experimental results, supported with numerical predictions, have shown that the photonuclear interrogation technique is quite capable of detecting shielded nuclear material via the direct measurement of the photofission-induced delayed neutron emissions. To identify or discriminate between nuclear material types (i.e., depleted uranium, HEU, and thorium), a ratio of delayed neutron counts at two different beam energies is utilized. This latter method, referred to as the dual-beam energy ratio Figure-of-Merit, allows one to differentiate among the three nuclear material types

Transformation of Cs-IONSIV® into a ceramic wasteform by hot isostatic pressing

A simple method to directly convert Cs-exchanged IONSIV® IE-911 into a ceramic wasteform by hot isostatic pressing (1100 °C/190 MPa/2 hr) is presented. Two major Cs-containing phases, Cs2TiNb6O18 and Cs2ZrSi6O15, and a series of mixed oxides form. The microstructure and phase assemblage of the samples as a function of Cs content were examined using XRD, XRF, SEM and TEM/EDX. The chemical aqueous durability of the materials was investigated using the MCC-1 and PCT-B standard test methods. For HIPed Cs-IONSIV® samples, the MCC-1 normalised release rates of Cs were <1.57 × 10−1 g m−2 d−1 at 0–28 days, and <3.78 × 10−2 g m−2 d−1 for PCT-B at 7 days. The low rates are indicative of a safe long-term immobilisation matrix for Cs formed directly from spent IONSIV®. It was also demonstrated that the phase formation can be altered by adding Ti metal due to a controlled redox environment

Adapting Agriculture to Climate Change: A Synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across Five Continents

The Adapting Agriculture to Climate Change Project set out to improve the diversity, quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and 2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we describe the implementation of the 25 national collecting programs and present the key results. A total of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety duplicated in national and international genebanks, and made available through the Multilateral System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most collected genepools, although the greatest number of primary genepool collections were made for rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets were best achieved. Several of the newly collected samples have already been used in pre-breeding programs to adapt crops to future challenges.info:eu-repo/semantics/publishedVersio