Natural Sponge Research Articles

Fabrication and characterization of Ag- and Ga-doped mesoporous glass-coated scaffolds based on natural marine sponges with improved mechanical properties.

Natural marine sponges were used as sacrificial template for the fabrication of bioactive glass-based scaffolds. After sintering at 1050°C, the resulting samples were additionally coated with a silicate solution containing biologically active ions (Ag and Ga), well-known for their antibacterial properties. The produced scaffolds were characterized by superior mechanical properties (maximum compressive strength of 4MPa) and total porosity of ~80% in comparison to standard scaffolds made by using PU foam templates. Direct cell culture tests performed on the uncoated and coated samples showed positive results in terms of adhesion, proliferation, and differentiation of MC3T3-E1 cells. Moreover, vascular endothelial growth factor (VEGF) secretion from cells in contact with scaffold dissolution products was measured after 7 and 10 days of incubation, showing promising angiogenic results for bone tissue engineering applications. The antibacterial potential of the produced samples was assessed by performing agar diffusion tests against both Gram-positive and Gram-negative bacteria.

MiRTissue ce: extending miRTissue web service with the analysis of ceRNA-ceRNA interactions

BackgroundNon-coding RNAs include different classes of molecules with regulatory functions. The most studied are microRNAs (miRNAs) that act directly inhibiting mRNA expression or protein translation through the interaction with a miRNAs-response element. Other RNA molecules participate in the complex network of gene regulation. They behave as competitive endogenous RNA (ceRNA), acting as natural miRNA sponges to inhibit miRNA functions and modulate the expression of RNA messenger (mRNA). It became evident that understanding the ceRNA–miRNA–mRNA crosstalk would increase the functional information across the transcriptome, contributing to identify new potential biomarkers for translational medicine.ResultsWe present miRTissue ce, an improvement of our original miRTissue web service. By introducing a novel computational pipeline, miRTissue ce provides an easy way to search for ceRNA interactions in several cancer tissue types. Moreover it extends the functionalities of previous miRTissue release about miRNA-target interaction in order to provide a complete insight about miRNA mediated regulation processes. miRTissue ce is freely available at http://tblab.pa.icar.cnr.it/mirtissue.html.ConclusionsThe study of ceRNA networks and its dynamics in cancer tissue could be applied in many fields of translational biology, as the investigation of new cancer biomarker, both diagnostic and prognostic, and also in the investigation of new therapeutic strategies of intervention. In this scenario, miRTissue ce can offer a powerful instrument for the analysis and characterization of ceRNA-ceRNA interactions in different tissue types, representing a fundamental step in order to understand more complex regulation mechanisms.

A natural polymer-based porous sponge with capillary-mimicking microchannels for rapid hemostasis

Natural polymer materials have attracted great attention in the field of hemostasis because of their wide range of source, nontoxicity, hydrophilicity, and air permeability. In the present study, two natural polymers composed of carboxymethyl chitosan (CMCS) and sodium carboxymethylcellulose (CMCNa) plus γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560) that serves as a crosslinking agent were selected to synthesize a capillary-mimicking composite hemostatic (CCK) sponge with a low density, interconnected microchannel architecture, suitable mechanical strength, high resilience, and ultrastrong liquid absorption capacity. The introduction of a large number of hydrophilic carboxymethyl functional groups and the design of capillary-mimicking structures formed by the ice segregation-induced self-assembly (ISISA) process endowed the CCK sponges with an ultrastrong liquid absorption capacity, which significantly enhanced the hemostatic ability of the materials. Both in vivo and in vitro hemostatic experiments confirmed the potential of the CCK sponges to achieve rapid hemostasis. Additionally, cytotoxicity and hemolysis assays showed that the CCK sponges exhibited good biocompatibility and hemocompatibility. The possible hemostatic mechanism was also discussed in this study. In conclusion, the capillary-mimicking hemostatic sponge exhibits a high potential to induce rapid hemostasis in prehospital emergency and clinical settings. STATEMENT OF SIGNIFICANCE: In the present study, an oriented composite hemostatic (CCK) sponge with a capillary-mimicking structure formed by the ice segregation-induced self-assembly (ISISA) process was designed and used to achieve rapid hemostasis. The unique aligned microchannel structure of the sponge exhibited an ultrastrong capillary-mimicking action and endowed the prepared CCK hemostatic sponge with a strong liquid absorption capacity. By changing the proportion of raw materials, we could modify the unique capillary-mimicking structure with aligned microchannels. Two natural polymer-based materials with abundant hydrophilic groups were chosen to prepare the CCK sponge to fully utilize the characteristics of this structure. The oriented natural polymer-based porous sponge with capillary-mimicking microchannels exhibited a strong hemostatic ability in both in vivo and in vitro tests. The results showed that the CCK sponge with the capillary-mimicking structure has a high potential to achieve rapid hemostasis.

Surface defective g-C3N4−xClx with unique spongy structure by polarization effect for enhanced photocatalytic removal of organic pollutants

Natural sponge is an ancient marine organism with a single lamellar structure, on which there are abundant porous channels to compose full-fledged spatial veins. Illumined by the natural spongy system, herein, the Cl doped surface defective graphite carbon nitride (g-C3N4−xClx) was constructed through microwave etching. In this process, microwave with HCl was employed to produce surface defects and peel bulk g-C3N4 to form natural spongy structured g-C3N4−xClx with three-dimensional networks. The spongy structure of the photocatalyst could provide abundant and unobstructed pathways for the transfer and separation of electron–hole pairs, and it was beneficial for photocatalytic reaction. The spongy defective g-C3N4−xClx achieved excellent degradation of diclofenac sodium (100%), bisphenol A (88.2%), phenol (85.7%) and methylene blue (97%) solution under simulated solar irradiation, respectively. The chlorine atoms were introduced into the g-C3N4 skeleton in microwave field with HCl, forming C–Cl bonds and surface polarization field, which could significantly accelerate the separation of photogenerated electrons and holes. As an efficient and universal approach, microwave etching can be generally used to create surface defects for most photocatalysts, which may have potential applications in environmental purification, energy conversion and photodynamic therapy.

Individual behavioral type captured by a Bayesian model comparison of cap making by sponge crabs.

‘Animal personality’ is considered to be developed through complex interactions of an individual with its surrounding environment. How can we quantify the ‘personality’ of an individual? Quantifying intra- and inter-individual variability of behavior, or individual behavioral type, appears to be a prerequisite in the study of animal personality. We propose a statistical method from a predictive point of view to measure the appropriateness of our assumption of ‘individual’ behavior in repeatedly measured behavioral data from several individuals. For a model case, we studied the sponge crab Lauridromia dehaani known to make and carry a ‘cap’ from a natural sponge for camouflage. Because a cap is most likely to be rebuilt and replaced repeatedly, we hypothesized that each individual crab would grow a unique behavioral type and it would be observed under an experimentally controlled environmental condition. To test the hypothesis, we conducted behavioral experiments and employed a new Bayesian model-based comparison method to examine whether crabs have individual behavioral types in the cap making behavior. Crabs were given behavioral choices by using artificial sponges of three different sizes. We modeled the choice of sponges, size of the trimmed part of a cap, size of the cavity of a cap, and the latency to produce a cap, as random variables in 26 models, including hierarchical models specifying the behavioral types. In addition, we calculated the marginal-level widely applicable information criterion (mWAIC) values for hierarchical models to evaluate and compared them with the non-hierarchical models from the predictive point of view. As a result, the crabs of less than about 9 cm in size were found to make caps from the sponges. The body size explained the behavioral variables namely, choice, trimmed cap characteristics, and cavity size, but not latency. Furthermore, we captured the behavioral type as a probabilistic distribution structure of the behavioral data by comparing WAIC. Our statistical approach is not limited to behavioral data but is also applicable to physiological or morphological data when examining whether some group structure exists behind fluctuating empirical data.

The Tumor-Suppressive Human Circular RNA CircITCH Sponges miR-330-5p to Ameliorate Doxorubicin-Induced Cardiotoxicity Through Upregulating SIRT6, Survivin, and SERCA2a.

Doxorubicin is one of the most potent antitumor agents available; however, its clinical use is restricted because it poses a risk of severe cardiotoxicity. Previous work has established that CircITCH (circular RNA ITCH [E3 ubiquitin-protein ligase]) is a broad-spectrum tumor-suppressive circular RNA and that its host gene, ITCH (E3 ubiquitin protein ligase), is involved in doxorubicin-induced cardiotoxicity (DOXIC). Whether CircITCH plays a role in DOXIC remains unknown. We aimed to dissect the role of CircITCH in DOXIC and further decipher its potential mechanisms. Circular RNA sequencing was performed to screen the potentially involved circRNAs in DOXI pathogenesis. Quantitative polymerase chain reaction and RNA in situ hybridization revealed that CircITCH was downregulated in doxorubicin-treated human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) as well as in the autopsy specimens from cancer patients who suffered from doxorubicin-induced cardiomyopathy. Cell death/viability assays, detection of cardiomyocyte necrosis markers, microelectrode array, and cardiomyocyte functional assays revealed that CircITCH ameliorated doxorubicin-induced cardiomyocyte injury and dysfunction. Detection of cellular/mitochondrial oxidative stress and DNA damage markers verified that CircITCH alleviated cellular/mitochondrial oxidative stress and DNA damage induced by doxorubicin. RNA pull-down assays, Ago2 immunoprecipitation and double fluorescent in situ hybridization identified miR-330-5p as a direct target of CircITCH. Moreover, CircITCH was found to function by acting as an endogenous sponge that sequestered miR-330-5p. Bioinformatic analysis, luciferase reporter assays, and quantitative polymerase chain reaction showed that SIRT6 (sirtuin 6), BIRC5 (baculoviral IAP repeat containing 5, Survivin), and ATP2A2 (ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 2, SERCA2a [SR Ca2+-ATPase 2]) were direct targets of miR-330-5p and that they were regulated by the CircITCH/miR-330-5p axis in DOXIC. Further experiments demonstrated that CircITCH-mediated alleviation of DOXIC was dependent on the interactions between miR-330-5p and the 3'-UTRs of SIRT6, BIRC5, and ATP2A2 mRNA. Finally, AAV9 (adeno-associated virus serotype 9) vector-based overexpression of the well-conserved CircITCH partly prevented DOXIC in mice. CircITCH represents a novel therapeutic target for DOXIC because it acts as a natural sponge of miR-330-5p, thereby upregulating SIRT6, Survivin and SERCA2a to alleviate doxorubicin-induced cardiomyocyte injury and dysfunction.

Effect Of Peppermint Oil On The Gastric Restriction Model With Phytobezoar In Wistar Rats

Obesity is a public health problem and many patients resort to bariatric surgeries as a form of treatment. However, surgical weight loss mechanisms, histopathological changes and long‐term consequences of bariatric surgery remain unclear. Among the main histopathological changes in the intestine we have increased expression of neutral mucins, acid mucins, caliciform cells and collagen in animals submitted to the gastric restriction model. Currently there is no therapeutic tool to reduce histopathological and oxidative changes promoted by gastric restriction surgeries. Based on these premises, the aim of this work was to investigate whether Peppermint essential oil reduces histopathological and oxidative changes in the experimental gastric restriction model. Adult male Wistar rats weighing between 250 and 400 grams were used. The animals were submitted to surgical gastrostomy and a cylindrical natural sponge (1.5 cm in diameter) was inserted into the stomach. The rats were separated into 3 groups, namely: Control (treated only with saline), Sham (surgical procedure only) and treatment (peppermint oil 100mg/Kg orally). Weight, water and food consumption were measured daily. On the last day all animals were euthanized and had the biological material collected (stomach, duodenum and jejunum) for histopathological evaluation and malondialdehyde (MDA) concentration in tissue. It was found that peppermint oil was able to reduce histopathological changes caused by the phytobenzoar in duodenum and jejunum, as well as to reduce the concentration of MDA in the jejunum (Figure 2). Regarding feed intake, the control group presented lower average consumption (98.7g/animal) when compared with Sham (134g/animal) and treatment groups (132g/animal). Regarding the average weight of the animals, it was observed that there was no statistically significant difference. It was found that peppermint essential oil presented moderate protective effect on phytobenzoar‐induced gastric restriction and reduced the loss of the architecture of intestinal viles.

Evaluation of different sponge types on the survival and infectivity of stored entomopathogenic nematodes

Sponges are one of the cheapest and most suitable substrates used to formulate and/or store the infective juveniles (IJs) of entomopathogenic nematodes (EPNs). Our study investigated the survival and infectivity of the IJs on five different sponges compared to that in an aqueous suspension (control). The sponges were Oasis® floral, Nanosponge, ScotchbriteTM, or Lysol® and natural sea sponge. EPN species tested were Heterorhabditis bacteriophora, Steinernema carpocapsae and S. feltiae. The recovery efficiency of the IJs from sponges was initially assessed. Subsequently, IJs were stored in the sponges and placed in plastic bags or Falcon tubes and incubated at 10° or 27 °C for 8 months or 11 weeks, respectively. IJ survival and infectivity were monitored monthly for the 10 °C and weekly for 27 °C in these sponge types. The IJs were recovered from the sponges, and their survival was based on observing their movement under a dissecting microscope, and infectivity was based on larval mortality in Galleria mellonella. Recovery efficiency of IJs was best for the Oasis floral sponge for all nematode species ranging between 83 and 91%. The survival and infectivity of stored IJs in all sponge types and control for both 10° and 27 °C gradually decreased over time. IJs stored in Scotchbrite, Lysol, and Nanosponge had the best survival and infectivity, whereas Oasis floral and natural sea sponges showed the poorest results. After 8 months at 10 °C in plastic bags, the survival ratio of all IJs in these three sponges (Scotchbrite, Lysol, and Nanosponge) was approximately 55%. IJs in Scotchbrite and Nanosponge were also able to survive and retain their infectivity at 27 °C for 3 months. IJs stored in Falcon tubes had survival that ranged from 26 to 53% at 27 °C and 55 to 77% at 10 °C. H. bacteriophora IJs lost their infectivity when stored at 27 °C after 10 weeks. However, S. carpocapsae and S. feltiae exhibited 85% infectivity when stored in Scotchbrite and 50% in Nanosponge, respectively. Overall, sponges made from polyurethane (Scotchbrite) followed by melamine (Nanosponge) and cellulose (Lysol) are recommended for long-term nematode storage and transportation of nematode samples. However, Oasis floral sponge may be preferred for short-term IJ formulation for field applications because of easier recovery of IJs.

Luffa sponge supported dendritic imidazolium ILs with high-density active sites as highly efficient and environmentally friendly catalysts for CO2 chemical fixation

Efficient using of green heterogeneous catalysts from renewable natural sources through chemical modification for the cycloaddition of terminal epoxides with CO2 is attractive but still challenging. Luffa sponge is a cheap, biodegradable, abundant and renewable source with netting-like three-dimensional porous structure. Herein, we report a simple and facile approach to the preparation of a series of novel luffa sponge-supported dendritic imidazolium ILs heterogeneous catalysts LS-DIL-(G1-G3) with high ionic density from natural luffa sponge fibers. LS-DIL-(G1-G3) were properly characterized by FT-IR spectroscopy, TGA, elemental analysis, and SEM. Among them, LS-DIL-G3 was found to exhibit the highest catalytic activity for the synthesis of cyclic carbonates under metal-free and solvent-free conditions. It was clearly observed that there was a positive dendritic effect on the yields of cyclic carbonates. Furthermore, a wide range of terminal epoxides was converted smoothly to the corresponding cyclic carbonates with high yields (84–99 %). LS-DIL-G3 could be reused for up to six consecutive runs without any obvious decline in catalytic activity. Importantly, the desired cyclic carbonates could be prepared on a multigram scale by using LS-DIL-G3 as a green heterogeneous catalyst.

Strong and Heat-Resistant SiC-Coated Carbonized Natural Loofah Sponge for Electromagnetic Interference Shielding

Renewable, processable, and efficient electromagnetic shielding materials have received great attention with the urgent requirement of alleviating the depletion of fossil resources and the harm of ...

DNA Nanosponge for Adsorption and Clearance of Intracellular miR-21 and Enhanced Antitumor Chemotherapy.

Antisense oligonucleotide (ASO)-induced cellular signaling pathway alteration is evolving as a promising therapeutic strategy for improving antitumor chemotherapy. However, the inherent instability and inefficiency of ASO delivery remain major hurdles for its application. Herein, we developed a self-assembled DNA nanosponge (DNS) for adsorption and clearance of intracellular miR-21. The densely packed DNA nanostructure is able to provide large amounts of repeated ASO copies for efficient capturing of miR-21 and inhibiting the miRNAs function in mammalian cells. The cell apoptosis-related protein expression (Bcl-2, Bax, and cleaved caspase-3/9) can be obviously interrupted with the delivery of DNS. Besides, we have shown that the DNS can efficiently carry Dox for chemotherapy and inducing tumor cell (MCF-7) apoptosis meanwhile has little affect to normal cells (Hs578 Bst). These polymeric DNS systems mimic the natural RNA circle-based miRNA sponges and have potential to be applied for specific and efficient regulation of gene expression in tumor cells for synergistic antitumor chemotherapy.

Reinforced alginate/gelatin sponges functionalized by avidin/biotin-binding strategy: a novel cardiac patch.

Adequate mechanical properties to withstand the surgical procedure and decoration with bioactive molecules promoting tissue regeneration are crucial aspects in the development of successful matrices for cardiac tissue engineering. The aim of this work was the development of a novel cardiac patch based on a blend of alginate and gelatin, designed to combine the improvement of suture resistance with an effective growth factor immobilization. We defined the procedures to incorporate a poly(dioxanone) membrane within the alginate/gelatin sponges and to functionalize the biomaterial with insulin-like growth factor-1, using the avidin–biotin-binding strategy. Morphological analysis of the reinforced scaffolds showed a porous structure and a good adhesion of the synthetic microporous membrane to the natural sponge. Infrared chemical imaging analysis demonstrated the efficacy of the chemical treatments performed for scaffold reinforcement and functionalization. A good hydrophilicity and an adequate permeability were shown by swelling and permeability tests. The inclusion of the synthetic membrane improved the viscoelastic properties, as measured by dynamic mechanical analysis, and the suture retention force under both dry and wet conditions. The in vitro and in vivo biological characterization showed that insulin-like growth factor-1 functionalization successfully enhanced cell adhesion and long-term retention after implantation on the damaged myocardium, together with improved suturability by poly(dioxanone) reinforcement.

Multifunctional Polymer Sponge with Molecule Recognition: Facile Mechanic Induced Separation.

Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation, but its fabrication is still challenging because some critical issues of selective adsorption, high mechanical strength, and easy collection/re-use are difficult to be achieved in one material. Here, inspired by natural sponges, novel multifunctional polymer sponges were developed which were fabricated by ice-templating with multifunctional amine polyethylenimine and diepoxide cross-linker poly(ethylene glycol) diglycidyl ether for highly efficient harvesting of dyes and simultaneous pure water recovery both in mechanic pressing and filtration processes. The as-prepared sponge (SP-1) was further modified by poly(caffeic acid) through a simple dipping-cross-linking process to obtain the hybrid polymer sponge (SP-2), which showed higher compressive strength than SP-1. These sponges possessed a cross-linked three-dimensional macroporous structure with quick water absorbing properties over ten times of their own weight within 20 s directed by capillary. The adsorption behavior of the obtained polymer sponges to 11 hydrophilic dyes was studied in detail by mechanic induced separation. All these polymer sponges exhibited a high selective adsorption to hydrophilic dyes in water. For example, SP-1 has high adsorption capacity over 150 μmol/g to erythrosin B, which is 20 times higher than that of calcein. With the modified poly(caffeic acid) layer, SP-2 exhibited different adsorption properties for methylene blue (180 μmol/g) to SP-1 (∼0 μmol/g), indicating that the tailorable structures of the sponge can regulate their selectivity to guest molecules. Based on the unique recognition to guest molecules, the methodology of dynamic separation of the dye's mixture in water was demonstrated by using these sponges through mechanical pressing or fast filtration, which provides a facile alternative with easy operation for water purification.

Sponge-based microfluidic sampling for potentiometric ion sensing

This work demonstrates an application of the new materials, sponges, for the use in microfluidic solution sampling integrated with ion-selective electrodes. The microfluidic sponge-based sampling was developed and studied as novel sampling and sample handling method to serve as alternative for microfluidic paper- and textile-based sampling for ion analysis in various environmental (Cd2+, Pb2+ and pH) and clinically (K+, Na+, Cl−) relevant samples. Three types of polyurethane, cellulose and natural sponges were used as substrates for microfluidic solution sampling. Polyurethane based sponge was found to have low heavy metal sorption capacity thus it was recognized as suitable for microfluidic sampling coupled with solid-state as well as solid-contact ion-selective electrodes. The application of sponge-based microfluidic sampling, contrary to previous findings of paper- and textile-based microfluidic sampling, allowed measurements of heavy metals without prior modification of the sampling substrate. Finally, the determination of potassium, sodium and chloride in wastewater sludge and sweat samples done with sponge-based microfluidic sampling integrated with ISEs was found similar to analysis done by ICP-OES and IC.

Newly Designed Human-Like Collagen to Maximize Sensitive Release of BMP-2 for Remarkable Repairing of Bone Defects.

Designing the “ideal” hydrogel/matrix which can load bone morphogenetic protein-2 (BMP-2) in a low dose and with a sustained release is the key for its successful therapeutic application to enhance osteogenesis. The current use of natural collagen sponges as hydrogel/matrix is limited due to the collagen matrix showing weak mechanical strength and unmanageable biodegradability. Furthermore, the efficiency and safe dose usage of the BMP-2 has never been seriously considered other than purely chasing the lowest dose usage and extended-release time. In this paper, we customized a novel enzymatically cross-linked recombinant human-like collagen (HLC) sponge with low immunogenicity, little risk from hidden viruses, and easy production. We obtained a unique vertical pore structure and the porosity of the HLC, which are beneficial for Mesenchymal stem cells (MSCs) migration into the HLC sponge and angiopoiesis. This HLC sponge loading with low dose BMP-2 (1 µg) possessed high mechanical strength along with a burst and a sustained release profile. These merits overcome previous limitations of HLC in bone repair and are safer and more sensitive than commercial collagens. For the first time, we identified that a 5 µg dose of BMP-2 can bring about the side effect of bone overgrowth through this sensitive delivery system. Osteoinduction of the HLC-BMP sponges was proved by an in vivo mouse ectopic bone model and a rat cranial defect repair model. The method and the HLC-BMP sponge have the potential to release other growth factors and aid other tissue regeneration. Additionally, the ability to mass-produce HLC in our study overcomes the current supply shortage, which limits bone repair in the clinic.

Cocaine induces differential circular RNA expression in striatum

Circular RNA (circRNA), a novel type of endogenous non-coding RNA, plays natural miRNA sponge effect that represses the activities of corresponding miRNAs through binding with them, thus modulating transcriptional expression of genes. Recent studies indicate that circRNAs are significantly enriched in the brain and some of them are derived from synaptic protein-coding genes. In addition, miRNAs are involved in synaptic plasticity, memory formation, and cocaine addiction. However, the role of circRNAs in cocaine reward is unclear. This study aimed to investigate the expression profile of striatal circRNAs in the mice after cocaine self-administration. By using circRNA microarray analysis, we observed that 90 striatal circRNAs were differentially expressed in cocaine self-administering mice, of which 18 circRNAs were up-regulated and 72 down-regulated. Six circRNAs were selected randomly for validation by using quantitative reverse transcription-PCR, and their expression levels showed consistency with microarray analysis. We backward predicted the circRNAs and their binding sites of miRNAs associated with neuroplasticity. In functional validation test, mmu_circRNA_002381 may modulate the transcription of certain genes associated with neuroplasticity, such as limk1 and bdnf. Taken together, circRNAs may participate in cocaine behavioral effect via interacting with miRNAs. Our findings reveal a potential role of circRNAs in cocaine effect.

Dark Peripatetic Walking as Radical Wandering in Cheryl Strayed’s Memoir <em>Wild</em>

Dark Peripatetic Walking as Radical Wandering in Cheryl Strayed’s Memoir <em>Wild</em>

Modified natural loofah sponge as an effective heavy metal ion adsorbent: Amidoxime functionalized poly(acrylonitrile-g-loofah)

Natural loofah sponge is a low cost adsorbent, but its adsorption property needs to be improved. A grafted copolymer of poly(acrylonitrile-g-loofah) [poly(AN-g-loofah)] was prepared using cericammonium nitrate (CAN) as initiator. The poly(AN-g-loofah) was further functionalized into a amidoxime-modified poly(AN-g-loofah), which was characterized through FT-IR, X-ray diffraction, and thermogravimetric analysis. The adsorption capacity of amidoxime-modified poly(AN-g-loofah) was investigated under different adsorption conditions. Amidoxime-modified poly(AN-g-loofah) with approximately 70% conversion of the nitrile group could adsorb 51.40mg/g Cu2+, which is more than two times higher than that obtained by previous studies. The modified Langmuir isotherm model and pseudo-second-order model fitted well with the Cu2+ adsorption data. A good adsorption amount of Cu2+ was obtained after five adsorption–deadsorption cycles. Hence, amidoxime-modified poly(AN-g-loofah) could be used as a novel substance for waste water treatment in industrial level.

Manufacturing process and properties of lead-free natural rubber sponge for use in X-ray and gamma ray shielding applications

In this work, light-weighted, flexible, and lead-free X-ray/gamma-ray shielding natural rubber (NR) sponges were developed with the help of a blowing agent, namely Oxybis (benzene sulfonyl) hydrazide (OBSH) (its contents varied from 0, 8 to 16 parts per hundred parts of rubber; phr), and an X-ray/gamma protective filler, namely bismuth oxide (Bi2O3) (its content varied from 0, 100, 300, to 500 phr) in natural rubber (NR) composites. The results suggested that the densities and overall mechanical properties decreased with increasing contents of OBSH, while the increases in B2O3 resulted in the increases in tensile strength and hardness (Shore A), however, initially increases tensile strength and elongation at break but later decreases at 300 and 500 phr. In terms of radiation shielding properties, it was found that the ability to attenuate X-rays and gamma rays improved with increasing Bi2O3 contents. Hence, the overall properties investigated in this work suggested that the developed NR sponges could be used to attenuate X-rays and gamma rays efficiently with additional properties of being light-weighted and highly flexible, which are crucial for safety of radiation-related personnel and users.

Bioactive behavior of mesoporous silica particle (MCM‐41) coated bioactive glass‐based scaffolds

AbstractA complete characterization of a novel family of multifunctional bioactive glass (45S5 composition) (BG)‐based scaffolds for bone tissue engineering is presented. Scaffolds were developed via replication method of polyurethane packaging foam and natural marine sponge “Spongia Agaricina”. In order to increase the therapeutic functionality, the scaffolds were coated with mesoporous silica particles (MCM‐41), which can act as drug delivery carrier, increase the bioactivity of the combined system and release Si ions, essential for the gene stimulation of osteoblast cells and for inducing new bone matrix formation. The MCM‐41 particles were synthetized directly inside the scaffolds (CCM) or after the synthesis they were dispersed in ethanol and used for impregnation (PCM) of the scaffolds. The effect of the particles on the bioactivity of the scaffolds was assessed in simulated body fluid (SBF) for up to 7 days. The results indicate the possibility to obtain a multifunctional BG‐scaffold system with enhanced bioactivity and reduced pH increase when in contact with physiological fluids.