Composite Aerogel Scaffolds Containing Flexible Silica Nanofiber and Tricalcium Phosphate Enable Skin Regeneration.

Poor hemostatic ability and less vascularization at the injury site could hinder wound healing as well as adversely affect the quality of life (QOL). An ideal wound dressing should exhibit certain characteristics: (a) good hemostatic ability, (b) rapid wound healing, and (c) skin appendage formation. This necessitates the advent of innovative dressings to facilitate skin regeneration. Therapeutic ions, such as silicon ions (Si4+) and calcium ions (Ca2+), have been shown to assist in wound repair. The Si4+ released from silica (SiO2) can upregulate the expression of proteins, including the vascular endothelial growth factor (VEGF) and alpha smooth muscle actin (α-SMA), which is conducive to vascularization; Ca2+ released from tricalcium phosphate (TCP) can promote the coagulation alongside upregulating the expression of cell migration and cell differentiation related proteins, thereby facilitating the wound repair. The overarching objective of this study was to exploit short SiO2 nanofibers along with the TCP to prepare TCPx@SSF aerogels and assess their wound healing ability. Short SiO2 nanofibers were prepared by electrospinning and blended with varying proportions of TCP to afford TCPx@SSF aerogel scaffolds. The TCPx@SSF aerogels exhibited good cytocompatibility in a subcutaneous implantation model and manifested a rapid hemostatic effect (hemostatic time 75 s) in a liver trauma model in the rabbit. These aerogel scaffolds also promoted skin regeneration and exhibited rapid wound closure, epithelial tissue regeneration, and collagen deposition. Taken together, TCPx@SSF aerogels may be valuable for wound healing.

Electrospinning of poly(ethylene oxide)/glass hybrid nanofibres for anticounterfeiting encoding.

The use of photochromism to increase the credibility of consumer goods has shown great promise. To provide mechanically dependable anticounterfeiting nanofibres, it has also been critical to improve the engineering processes of authentication patterns. Mechanically robust and photoluminescent electrospun poly(ethylene oxide)/glass (PGLS) nanofibres (150-350 nm) immobilized with nanoparticles of lanthanide-doped aluminate (NLA; 8-15 nm) were developed using electrospinning technology for anticounterfeiting purposes. The provided nanofibrous membranes changed colour from transparent to green when irradiated with ultraviolet light. By delivering NLA with homogeneous distribution without aggregations, we were able to keep the nanofibrous membrane transparent. When excited at 365 nm, NLA@PGLS nanofibres showed an emission intensity at 517 nm. The hydrophobicity of NLA@PGLS nanofibres improved by raising the pigment concentration as the contact angle was increased from 146.4° to 160.3°. After being triggered by ultraviolet light, NLA@PGLS showed quick and reversible photochromism without fatigue. It was shown that the suggested method can be applied to reliably produce various anticounterfeiting materials.

Development of 3D printed electrospun vascular graft loaded with tetramethylpyrazine for reducing thrombosis and restraining aneurysmal dilatation.

Background: Small-diameter vascular grafts have become the focus of attention in tissue engineering. Thrombosis and aneurysmal dilatation are the two major complications of the loss of vascular access after surgery. Therefore, we focused on fabricating 3D printed electrospun vascular grafts loaded with tetramethylpyrazine (TMP) to overcome these limitations. Methods: Based on electrospinning and 3D printing, 3D-printed electrospun vascular grafts loaded with TMP were fabricated. The inner layer of the graft was composed of electrospun poly(L-lactic-co-caprolactone) (PLCL) nanofibers and the outer layer consisted of 3D printed polycaprolactone (PCL) microfibers. The characterization and mechanical properties were tested. The blood compatibility and in vitro cytocompatibility of the grafts were also evaluated. Additionally, rat abdominal aortas were replaced with these 3D-printed electrospun grafts to evaluate their biosafety. Results: Mechanical tests demonstrated that the addition of PCL microfibers could improve the mechanical properties. In vitro experimental data proved that the introduction of TMP effectively inhibited platelet adhesion. Afterwards, rat abdominal aorta was replaced with 3D-printed electrospun grafts. The 3D-printed electrospun graft loaded with TMP showed good biocompatibility and mechanical strength within 6 months and maintained substantial patency without the occurrence of acute thrombosis. Moreover, no obvious aneurysmal dilatation was observed. Conclusions: The study demonstrated that 3D-printed electrospun vascular grafts loaded with TMP may have the potential for injured vascular healing.

Preparation of photoluminescent nano-biocomposite nacre from graphene oxide and polylactic acid.

Nano-biocomposites of inorganic and organic components wereprepared to produce long-persistent phosphorescent artificial nacre-like materials. Biodegradable polylactic acid (PLA), graphene oxide (GO), and nanoparticles (13-20 nm) of lanthanide-doped aluminate pigment (NLAP) were used in a simple production procedure of an organic/inorganic hybrid nano-biocomposite. Both polylactic acid and GO nanosheets were chemically modified to form covalent and hydrogen bonding. The high toughness, good tensile strength, and great endurance of those bonds were achieved by their interactions at the interfaces. Long-persistent and reversible photoluminescence was shown by the prepared nacre substrates. Upon excitation at 365 nm, the nacre substrates generated an emission peak at 517 nm. When ultraviolet light was shone on luminescent nacres, they displayed a bright green colour. The high superhydrophobicity of the generated nacres was obtained without altering their mechanical characteristics.

Aspirin-Loaded Anti-Inflammatory ZnO-SiO2 Aerogel Scaffolds for Bone Regeneration.

The increasing aging of the population has elevated bone defects to a significant threat to human life and health. Aerogel, a biomimetic material similar to an extracellular matrix (ECM), is considered an effective material for the treatment of bone defects. However, most aerogel scaffolds suffer from immune rejection and poor anti-inflammatory properties and are not well suited for human bone growth. In this study, we used electrospinning to prepare flexible ZnO-SiO2 nanofibers with different zinc concentrations and further assembled them into three-dimensional composite aerogel scaffolds. The prepared scaffolds exhibited an ordered pore structure, and chitosan (CS) was utilized as a cross-linking agent with aspirin (ASA). Interestingly, the 1%ZnO-SiO2/CS@ASA scaffolds not only exhibited good biocompatibility, bioactivity, anti-inflammation, and better mechanical properties but also significantly promoted vascularization and osteoblast differentiation in vitro. In the mouse cranial defect model, the BV/TV data showed a higher osteogenesis rate in the 1%ZnO-SiO2/CS group (10.94 ± 0.68%) and the 1%ZnO-SiO2/CS@ASA group (22.76 ± 1.83%), compared with the control group (5.59 ± 2.08%), and in vivo studies confirmed the ability of 1%ZnO-SiO2/CS@ASA to promote in situ regeneration of new bone. This may be attributed to the fact that Si4+, Zn2+, and ASA released from 1%ZnO-SiO2/CS@ASA scaffolds can promote angiogenesis and bone formation by stimulating the interaction between endothelial cells (ECs) and BMSCs, as well as inducing macrophage differentiation to the M2 type and downregulating the expression of pro-inflammatory factor (TNF-α) to modulate local inflammatory response. These exciting results and evidence suggest that it provides a new and effective strategy for the treatment of bone defects.

Fabrication of biodegradable and antibacterial films of chitosan/polyvinylpyrrolidone containing Eucalyptus citriodora extracts.

The main objective of this work is to develop biodegradable active films through the combination of the extracts with different solvents sourced from Eucalyptus citriodora leaves, with films made of chitosan (Cs) and polyvinylpyrrolidone (PVP). Chromatographic profiling investigations were carried out to examine the antibacterial characteristics of E. citriodora extracts before their direct incorporation into the polymer films. At this point, the potent antimicrobial properties of the phenol compounds and bioactive components demonstrated an antibacterial activity that was particularly noticeable at a hexane resolution. Different morphological characteristics were seen on films made from these solvent extracts, such as Cs/PVP-AE, Cs/PVP-EAE, and Cs/PVP-HE, when scanning electron microscopy was used. Numerous other outcomes of all the interactions between the extract particles and the film were shown by the pores defined by the Cs/PVP film's porous nature. The addition of the extracts, either alone or in combination, greatly enhanced the Cs/NC/PVP films' mechanical characteristics. It has also been shown that adding plant extracts greatly increased the antibacterial activity of these films. These findings reveal that Cs/PVP films loaded with extract may be utilized as more environmentally acceptable substitutes for possible food packaging application by increasing shelf life of food products.

Electrospun membranes chelated by metal magnesium ions enhance pro-angiogenic activity and promote diabetic wound healing.

Diabetic wounds, resulting from skin atrophy due to localized ischemia and hypoxia in diabetic patients, lead to chronic pathological inflammation and delayed healing. Using electrospinning technology, we developed magnesium ion-chelated nanofiber membranes to explore their efficacy in antibacterial, anti-inflammatory, and angiogenic applications for wound healing. These membranes are flexible and elastic, resembling native skin tissue, and possess good hydrophilicity for comfortable wound bed contact. The mechanical properties of nanofiber membranes are enhanced by the chelation of magnesium ions (Mg2+), which also facilitates a long-term slow release of Mg2+. The cytocompatibility of the nanofibrous membranes is influenced by their Mg2+ content: lower levels encourage the proliferation of fibroblasts, endothelial cells, and macrophages, while higher levels are inhibitory. In a diabetic rat model, magnesium ion-chelated nanofibrous membranes effectively reduced early wound inflammation and notably accelerated wound healing. This study highlights the potential of magnesium ion-chelated nanofiber membranes in treating diabetic wounds.

Waste polyethylene terephthalate plastic derived Zr-MOF for high performance supercapacitor applications.

The chemical conversion of plastic waste into metal-organic framework (MOF) materials has emerged as a significant research field in addressing issues associated to the environment and the economy. The significant advantages of MOFs as electrode material for energy/supercapacitors arises from their extensive surface area and notable porosity. The present study involved the synthesis of Zirconium-Metal Organic Frameworks (Zr-MOF) by the solvothermal method, utilizing plastic waste in the form of Polyethylene terephthalate (PET) bottles. The morphological and structural characteristics of the Zr-MOF were inspected through several analytical techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy analysis. The as prepared Zr-MOF demonstrated very high specific surface area of 927.567 m2 g-1 with mesoporous nature of the materials estimate by BJH method. The electrochemical characteristics of the Zr-MOF in 3-electrode system exhibited a notable specific capacitance of 822 F g-1 when subjected to a low scan rate of 2 mV S-1, while the specific capacitance estimated through galvanostatic charge-discharge exhibited an enhanced value of 890 F g-1 at a current density of 0.5 A g-1. Additionally, the working electrode composed of Zr-MOF demonstrated noteworthy capacitance retention of 92% after 5000 charge discharge cycles. This research presents novel opportunities for the utilization of waste PET bottles in fabrication of highly functional Zr-MOF, aiming to advance the development of next-generation supercapacitors and environmental remediation.

Fiber configuration determines foreign body response of electrospun scaffolds:in vitroandin vivoassessments.

Biomaterial scaffolds boost tissue repair and regeneration by providing physical support, delivering biological signals and/or cells, and recruiting endogenous cells to facilitate tissue-material integration and remodeling. Foreign body response (FBR), an innate immune response that occurs immediately after biomaterial implantation, is a critical factor in determining the biological outcomes of biomaterial scaffolds. Electrospinning is of great simplicity and cost-effectiveness to produce nanofiber scaffolds with well-defined physicochemical properties and has been used in a variety of regenerative medicine applications in preclinical trials and clinical practice. A deep understanding of causal factors between material properties and FBR of host tissues is beneficial to the optimal design of electrospun scaffolds with favorable immunomodulatory properties. We herein prepared and characterized three electrospun scaffolds with distinct fiber configurations and investigated their effects on FBR in terms of immune cell-material interactions and host responses. Our results show that electrospun yarn scaffold results in greater cellular immune reactions and elevated FBR inin vivoassessments. Although the yarn scaffold showed aligned fiber bundles, it failed to induce cell elongation of macrophages due to its rough surface and porous grooves between yarns. In contrast, the aligned scaffold showed reduced FBR compared to the yarn scaffold, indicating a smooth surface is also a contributor to the immunomodulatory effects of the aligned scaffold. Our study suggests that balanced porousness and smooth surface of aligned fibers or yarns should be the key design parameters of electrospun scaffolds to modulate host responsein vivo.

Electrospinning of photochromic poly(ethylene terephthalate) nanofibers toward information authentication.

The use of photochromism to enhance the anti-counterfeiting of a wide range of economic goods is an intriguing prospect. Creating a translucent anti-counterfeiting nanocomposite is critical to improving the engineering procedures of the encoding materials. Herein, we use electrospinning to produce anti-counterfeiting nanofibrous films from nanoparticles of rare-earth aluminate (NREA) and recycled poly(ethylene terephthalate) (PET). Different nanofiber films with distinct emission properties were created using different ratios of NREA. The ultraviolet (UV)-induced photochromism of the NREA@PET nanofibers was proved. Immobilizing NREA at the nanoscale ensures better dispersion without agglomeration in the PET nanofibrous matrix, which is essential for the development of transparent NREA@PET films. Diameters of 4-13 nm for NREA were shown using transmission electron microscopy. X-ray fluorescence spectroscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, elemental mapping, and other techniques were used to investigate the photochromic nanofibers' morphology, elemental contents, optical transmittance, and mechanical performance. It was observed that the nanofiber diameter in NREA@PET was between 150 and 250 nm. Excitation and emission bands of electrospun NREA@PET nanofibrous films were monitored at 365 and 518 nm, respectively. The superhydrophobicity of NREA@PET increased with increasing NREA concentration. The transparent nanofibers exhibited fast and reversible dual-mode fluorescent photochromism to green emission without fatigue when stimulated beneath a UV source. Using the present anti-counterfeiting films can be regarded as a simple technique to develop flexible materials to launch an ideal marketplace with affordable societal and economic advantages.

Elastic 3D-Printed Nanofibers Composite Scaffold for Bone Tissue Engineering.

Loading nanoparticles into hydrogels has been a conventional approach to augment the printability of ink and the physicochemical characteristics of scaffolds in three-dimensional (3D) printing. However, the efficacy of this enhancement has often proven to be limited. We amalgamate electrospun nanofibers with 3D printing techniques to fabricate a composite scaffold reminiscent of a "reinforced concrete" structure, aimed at addressing bone defects. These supple silica nanofibers are synthesized through a dual-step process involving high-speed homogenization and low-temperature ball milling technology. The nanofibers are homogeneously blended with sodium alginate to create the printing ink. The resultant ink was extruded seamlessly, displaying commendable molding properties, thereby yielding scaffolds with favorable macroscopic morphology. In contrast to nanoparticle-reinforced scaffolds, composite scaffolds containing nanofibers exhibit superior mechanical attributes and bioactivity. These nanofiber composite scaffolds demonstrate enhanced osteoinductive properties in both in vitro and in vivo evaluations. To conclude, this research introduces a novel 3D printing approach where the fabricated nanofiber-infused 3D-printed scaffolds hold the potential to revolutionize the realm of 3D printing in the domain of bone tissue engineering.

Development of hydrophobic, mechanically reliable, and glow-in-the-dark glue using Arabic gum.

A smart nanocomposite adhesive was created to facilitate a simple production of long-persistent photoluminescent and hydrophobic commercial products. Even after being left in the dark for up to 90 min, the created photoluminescent adhesive agent continued to generate light. A surface-specific nanocomposite adhesive agent consisting of lanthanide-activated strontium aluminate (LSA) nanoparticles (NPs; 5-14 nm) immobilized in the environmentally friendly Arabic gum (AG) was developed. A light-transmitting nanocomposite adhesive agent was manufactured by dispersing LSA nanoparticles evenly across the AG matrix without agglomeration. An excitation peak at 365 nm and an emission wavelength at 519 nm were observed for the prepared adhesives at different concentrations of LSA NPs. The emission spectra showed either fluorescence or afterglow phosphorescence, depending on the LSA ratio. The photochromic transition from colourless to green beneath an ultraviolet (UV) lamp and greenish yellow in a dark room was tracked. The LSA NPs in the Arabic gum matrix imparted enhanced hydrophobicity and scratch resistance to the LSA@AG nanocomposite. The LSA@AG nanocomposite demonstrated excellent durability and photostability. This study confirmed that the mass production of smart adhesives for applications such as smart windows, smart packaging, and safety directional signs in buildings is possible.

Immobilization of lanthanide doped aluminate phosphor onto recycled polyester toward the development of long-persistent photoluminescence smart window.

Smart window can be defined as switchable material whose light transmission is altered upon exposure to light, voltage, or heat. However, smart windows are usually produced from expensive and breakable glass materials. Herein, transparent smart window with long-persistent phosphorescence, high optical transmittance, ultraviolet (UV) protection, rigid, high photostability and durability, an d superhydrophobicity was developed from recycled polyester (PET). Recycled polyester waste (RBW) was simply immobilized with different ratios of lanthanide-doped aluminate nanoparticles (LdAN) to provide a long-persistent phosphorescent polyester smart window (LdAN@PET) with an abili ty to persist emitting light for extended time periods. The solid-state high temperature technique was used to prepare lanthanide-doped aluminate (LdA) micro-scale powder. Then, the top-down technique was applied to afford the corresponding LdAN. Recycled shredded recycled polyester bottles were charged into a hot bath to provide a clear plastic shred bulk, which was then well-mixed with LdAN and drop-casted to provide long-persistent luminescent smart window. In order to improve the phosphor dispersion in the PET bulk, LdAN was synthesized in the nanoparticle form which was characterized utilizing transmission electron microscopy (TEM). For better preparation of translucent smart window of long-persistent phosphorescent polyester, LdAN must be homogeneously dispersed in the PET matrix without agglomeration. The morphology and chemical composition were studied by Fourier-transform infrared (FTIR) spectra), X-ray fluorescence (XRF) analysis, scanning electron microscopy (SEM), and energy-dispersion X-ray spectroscopy (EDX). In addition, spectral profiles of excitation and emission, and decay and lifetime were used to better understand the photoluminescence properties. The hardness properties were also investigated. The developed phosphorescent transparent polyester smart window demonstrated a color switch to intense green underneath UV irradiation and greenish-yellow under darkness as verified by CIELab color parameters. The afterglow polyester smart window showed an absorption wavelength at 365 nm and two phosphorescence intensities at 442 and 512 nm. An enhanced UV protection, photostability and hydrophobic activity were detected. The luminescent polyester substrates with lower LdAN ratios demonstrated rapid and reversible fluorescent photochromic activity beneath the UV light. The luminescent polyester substrates with higher LdAN contents displayed long-persistent phosphorescence afterglow. The current strategy can be simply applied for the production of smart windows, low thickness anti-counterfeiting films and warning signs.

Fabrication, microstructure characterization, and degradation performance of electrospun mats based on poly(3-hydroxybutyrate-co-3 hydroxyvalerate)/polyethylene glycol blend for potential tissue engineering.

There have been strong demands for nanofibrous scaffolds fabricated by electrospinning for various fields due to their various advantages. Electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) fibre mats were prepared. The effects of processing variables as well as the inclusion of poly(ethylene glycol) (PEG) on the morphologies of generated fibres were investigated using Fourier-transform infrared spectroscopy and scanning electron microscopy. The average fibrous diameter was monitored in the range 400-3000 nm relying on the total content of PEG. The fluorescence cell imaging of electrospun mats was also explored. The results of cell viability demonstrated that skin fibroblast BJ-1 cells showed different adhesions and growth rates for the three kinds of PHBV fibres. Electrospun PHBV mats with low amount of PEG offer a high-quality medium for cell growth. Therefore, those mats exhibited high potential for soft tissue engineering, in particular wound healing.