Project description:Developing superabsorbents for efficiently separating immiscible oil-water mixtures and oil-water emulsions are highly desirable for addressing oily wastewater pollution problems, but it remains a challenge. Ultralight nanofibrous aerogels (NFAs) with unique wetting properties show great potential in oily wastewater treatment. In this study, a facile and efficient method for producing hierarchical porous structured NFAs with hydrophobicity for high efficiency oil-water separation was developed. The synthesis included three steps: wet electrospinning, freeze drying, and in situ polymerization. The obtained NFA demonstrated outstanding oil absorption capacity toward numerous oils and organic solvents, as well as efficient surfactant-stabilized water-in-oil emulsion separation with high separation flux and excellent separation efficiency. Furthermore, these NFAs displayed excellent corrosion resistance and outstanding recoverability. We assume that the resultant NFAs fabricated by this facile strategy are highly promising as ideal oil absorbents for practical oily wastewater treatment under harsh conditions.
Project description:Nanofibers can be utilized to overcome the challenges faced by conventional ophthalmic formulations. This study aimed to develop and characterize cysteamine (Cys)-loaded nanofiber-based ophthalmic inserts (OIs) as a potential candidate for the treatment of ophthalmic cystinosis using water-soluble polyvinyl alcohol (PVA)/poloxamer 407 (PO-407) and water-insoluble tetraethoxysilane (TEOS)/PVA nanofibers. Plain and Cys-loaded fibers in different proportions were prepared by the electrospinning method and studied for their morphological, physicochemical, release study, cytocompatibility effects, and stability study. The fiber formation was confirmed by scanning electron microscopy, while Fourier transform infrared spectra showed the most critical peaks for the Cys and the excipients. The release of the Cys was fast from the two polymeric matrices (≤20 min). The release from TEOS/PVA nanofibers is characterized by Case II transport (0.75 < β < 1), while the release from PVA/PO-407 nanofibers follows Fickian diffusion (β < 0.75). The cytocompatibility of compositions was confirmed by hen eggs tested on the chorioallantoic membrane (HET-CAM) of chick embryos. All formulations remained stable under stress conditions (40 ± 2 °C, 75 ± 5% relative humidity) regarding morphology and physicochemical characteristics. The developed nanofibrous mats could be an excellent alternative to available Cys drops, with better stability and convenience of self-administration as OIs.
Project description:Oleogels are becoming an attractive research field, since they have recently been shown to be feasible for the food and pharmaceutical sectors and provided some insights into the biomedical area. In this work, edible oleogels were tailored through the combination of ethylcellulose (EC), a gelling agent, with virgin coconut oil (VCO), vegetable oil derived from coconut. The influence of the different EC and VCO ratios on the structural, physical, and thermal properties of the oleogels was studied. All EC/VCO-based oleogels presented a stable network with a viscoelastic nature, adequate structural stability, modulable stiffness, high oil-binding capability, antioxidant activity, and good thermal stability, evidencing the EC and VCO's good compatibility.
Project description:The transcription factor WRINKLED1 (WRI1), a member of AP2 gene family that contain typical AP2 domains, has been considered as a master regulator regulating oil biosynthesis in oilseeds. However, the regulatory mechanism of RcWRI1 in regulating oil accumulation during seed development has not been clearly addressed. Castor bean (Ricinus communis) is one of the most important non-edible oil crops and its seed oils are rich in hydroxy fatty acids, widely applied in industry. In this study, based on castor bean reference genome, three RcWRIs genes (RcWRI1, RcWRI2 and RcWRI3) were identified and the expressed association of RcWRI1 with oil accumulation were determined. Heterologous transformation of RcWRI1 significantly increased oil content in tobacco leaf, confirming that RcWRI1 activate lipid biosynthesis pathway. Using DNA Affinity Purification sequencing (DAP-seq) technology, we confirmed RcWRI1 binding with Transcription Start Site of genes and identified 7961 WRI1-binding candidate genes. Functionally, these identified genes were mainly involved in diverse metabolism pathways (including lipid biosynthesis). Three cis-elements AW-box ([CnTnG](n)7[CG]) and AW-boxes like ([GnAnC](n)6[GC]/[GnAnC](n)7[G]) bound with RcWRI1 were identified. Co-expression network analysis of RcWRI1 further found that RcWRI1 might be widely involved in biosynthesis of storage materials during seed development. In particular, yeast one hybrid experiments found that both AP2 domains within RcWRI1 were required in binding targeted genes. These results not only provide new evidence to understand the regulatory mechanism of RcWRI1 in regulation of oil accumulation during castor bean seed development, but also give candidate gene resource for subsequent genetic improvement toward increasing oil content in oilseed crops.
Project description:Castor (Ricinus communis L.) seeds produce abundant ricinoleic acid during seed maturation, which is important for plant development and human demands. Ricinoleic acid, as a unique hydroxy fatty acid (HFA), possesses a distinct bond structure that could be used as a substitute for fossil fuels. Here, we identified all homologous genes related to glycolysis, hydroxy fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in castor seeds. Furthermore, we investigated their expression patterns globally during five seed development stages. We characterized a total of 66 genes involved in the glycolysis pathway, with the majority exhibiting higher expression levels during the early stage of castor bean seed development. This metabolic process provided abundant acetyl-CoA for fatty acid (FA) biosynthesis. Subsequently, we identified 82 genes involved in the processes of de novo FA biosynthesis and TAG assembly, with the majority exhibiting high expression levels during the middle or late stages. In addition, we examined the expression patterns of the transcription factors involved in carbohydrate and oil metabolism. For instance, RcMYB73 and RcERF72 exhibited high expression levels during the early stage, whereas RcWRI1, RcABI3, and RcbZIP67 showed relatively higher expression levels during the middle and late stages, indicating their crucial roles in seed development and oil accumulation. Our study suggests that the high HFA production in castor seeds is attributed to the interaction of multiple genes from sugar transportation to lipid droplet packaging. Therefore, this research comprehensively characterizes all the genes related to glycolysis, fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in the castor and provides novel insight into exploring the genetic mechanisms underlying seed oil accumulation in the endosperm of castor beans.
Project description:This work has been focused on the one-step fabrication by electrospinning of polyamide 6 (PA6) nanofibre membranes modified with titanium dioxide nanoparticles (TiO2), where these TiO2 nanoparticles aggregates could induce a photocatalytic activity. The main potential application of these membranes could be the purification of contaminated water. Thus, it is important to analyse the contaminant degradation capability since in these membranes this is based on their photocatalytic activity. In this work, the effect of the photocatalysis has been studied both on the degradation of an organic model contaminant and on the removal of Escherichia coli and other coliform bacteria. As a result, it was observed that these membranes present excellent photocatalytic activity when they are irradiated under UV light, allowing a 70% reduction of an organic model pollutant after 240 min. In addition, these membranes successfully removed Escherichia coli and other coliform bacteria in artificially inoculated water after 24 h of contact with them. Moreover, the stand-alone structure of the membranes allowed for the reusing of the immobilized catalyst. The experimental evidence indicated that developed nanofibre membranes are a fast and efficient solution for polluted water decontamination based on photocatalysis. Their use could contribute to guarantee a fresh water level and quality, mitigating the water scarcity problem worldwide.
Project description:Our long-term goal is to develop smart biomaterials that can facilitate regeneration of critical-size craniofacial lesions. In this study, we tested the hypothesis that biomimetic scaffolds electrospun from chitosan (CTS) will promote tissue repair and regeneration in a critical size calvarial defect. To test this hypothesis, we first compared in vitro ability of electrospun CTS scaffolds crosslinked with genipin (CTS-GP) to those of mineralized CTS-GP scaffolds containing hydroxyapatite (CTS-HA-GP), by assessing proliferation/metabolic activity and alkaline phosphatase (ALP) levels of murine mesenchymal stem cells (mMSCs). The cells' metabolic activity exhibited a biphasic behavior, indicative of initial proliferation followed by subsequent differentiation for all scaffolds. ALP activity of mMSCs, a surrogate measure of osteogenic differentiation, increased over time in culture. After 3 weeks in maintenance medium, ALP activity of mMSCs seeded onto CTS-HA-GP scaffolds was approximately two times higher than that of cells cultured on CTS-GP scaffolds. The mineralized CTS-HA-GP scaffolds were also osseointegrative in vivo, as inferred from the enhanced bone regeneration in a murine model of critical size calvarial defects. Tissue regeneration was evaluated over a 3 month period by microCT and histology (Hematoxylin and Eosin and Masson's Trichrome). Treatment of the lesions with CTS-HA-GP scaffolds induced a 38% increase in the area of de novo generated mineralized tissue area after 3 months, whereas CTS-GP scaffolds only led to a 10% increase. Preseeding with mMSCs significantly enhanced the regenerative capacity of CTS-GP scaffolds (by ?3-fold), to 35% increase in mineralized tissue area after 3 months. CTS-HA-GP scaffolds preseeded with mMSCs yielded 45% new mineralized tissue formation in the defects. We conclude that the presence of HA in the CTS-GP scaffolds significantly enhances their osseointegrative capacity and that mineralized chitosan-based scaffolds crosslinked with genipin may represent a unique biomaterial with possible clinical relevance for the repair of critical calvarial bone defects.
Project description:Lubrication is the key to efficient function of human tissues and has significant impact on the comfort level. However, the construction of a lubricating nanofibrous membrane has not been reported as yet, especially using a one-step surface modification method. Here, bioinspired by the superlubrication mechanism of articular cartilage, we successfully construct hydration-enhanced lubricating nanofibers via one-step in situ grafting of a copolymer synthesized by dopamine methacrylamide (DMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) onto electrospun polycaprolactone (PCL) nanofibers. The zwitterionic MPC structure provides the nanofiber surface with hydration lubrication behavior. The coefficient of friction (COF) of the lubricating nanofibrous membrane decreases significantly and is approximately 65% less than that of pure PCL nanofibers, which are easily worn out under friction regardless of hydration. The lubricating nanofibers, however, show favorable wear-resistance performance. Besides, they possess a strong antiadhesion ability of fibroblasts compared with pure PCL nanofibers. The cell density decreases approximately 9-fold, and the cell area decreases approximately 12 times on day 7. Furthermore, the in vivo antitendon adhesion data reveals that the lubricating nanofiber group has a significantly lower adhesion score and a better antitissue adhesion. Altogether, our developed hydration-enhanced lubricating nanofibers show promising applications in the biomedical field such as antiadhesive membranes.
Project description:In this study, silk fibroin was extracted from cocoons of silkworms and fabricated into nonwoven mats by electrospinning method. A new model based on the group method of data handling (GMDH) and artificial neural network (ANN) was developed for estimation of the average diameter of electrospun silk fibroin nanofibers. In this regard, concentration, flow rate, voltage, distance, and speed of collector were used as input parameters and average diameter of the fibers was considered as output parameter. Two models were capable to estimate average diameter of fibers with good accuracy. The average absolute relative deviation for GMDH and ANN models was equal to 3.56 and 2.28 %, respectively. Furthermore, due to importance of oxygen delivery to site of injury to promote wound healing, continuity equation for mass transport was employed for prediction of oxygen profile in the system containing wound dressing and skin. The result showed that our prepared wound dressing is capable to pass the oxygen completely to the skin layer and is not acting as a barrier for oxygen delivery to wound site. Since average nanofibers diameter can influence the mat physical, mechanical and biological properties then this model may serve as a useful guide to obtain tailor made and uniform silk nanofibers at various combinations of process variables.