Zwitter ionic modification of cobalt-ferrite nanofiber for the removal of anionic and cationic dyes

PDDA/Honey Antibacterial Nanofiber Composites for Diabetic Wound-Healing: Preparation, Characterization, and In Vivo Studies

In this paper, Poly (diallyldimethylammonium chloride) (PDDA)/honey nanofiber wound dressing composites were prepared and their effects on the diabetic wound-healing was evaluated using in vivo experiments. The release of effective compounds and the solubility of nanofibers were controlled through the crosslinking process by glutaraldehyde. The crosslinked nanofibers (crosslinking time was 3 h) showed an absorption capacity at a maximum value of 989.54%. Interestingly, the resultant composites were able to prevent 99.9% of Staphylococcus aureus and Escherichia coli bacteria. Furthermore, effective compounds were continuously released from nanofibers for up to 125 h. In vivo evaluation indicated that the use of PDDA/honey (40/60) significantly enhanced wound-healing. On the day 14th, the average healing rate for samples covered by conventional gauze bandage, PDDA, PDDA/honey (50/50), and PDDA/honey (40/60) were 46.8 ± 0.2, 59.4 ± 0.1, 81.7 ± 0.3, and 94.3 ± 0.2, respectively. The prepared nanofibers accelerated the wound-healing process and reduced the acute and chronic inflammation. Hence, our PDDA/honey wound dressing composites open up new future treatment options for diabetic wound diseases.

Preparation of Polyurethane/Pluronic F127 Nanofibers Containing Peppermint Extract Loaded Gelatin Nanoparticles for Diabetic Wounds Healing: Characterization, In Vitro, and In Vivo Studies

Diabetic ulcer is regarded as one of the most prevalent chronic diseases. The healing of these ulcers enhances with the use of herbal extracts containing wound dressings with high antibacterial property and creating a nano-sized controlled release system. In this study, new peppermint extract was incorporated in the polyurethane- (PU-) based nanofibers for diabetic wound healing. The peppermint extract was used as an herbal antimicrobial and anti-inflammatory agent. The absorption ability of the wound dressing was enhanced by addition of F127 pluronic into the polymer matrix. The release of the extract was optimized by crosslinking the extract with gelatin nanoparticles (CGN) and their eventual incorporation into the nanofibers. The release of the extract was also controlled through direct addition of the extract into the PU matrix. The results showed that the release of extract from nanofibers was continued during 144 hours. The prepared wound dressing had a maximum absorption of 410.65% and an antibacterial property of 99.9% against Staphylococcus aureus and Escherichia coli bacteria. An in vivo study indicated on significant improving in wound healing after the use of the extract as an effective compound. On day 14, the average healing rate for samples covered by conventional gauze bandage, PU/F127, PU/F/15 (contained extract), and PU/F/15/10 (contained extract and CGN) prepared with different nanoparticle concentrations of 5 and 10 was 47.1 ± 0.2, 56.4 ± 0.4, 65.14 ± 0.2, and 90.55 ± 0.15%, respectively. Histopathological studies indicated that the wound treated with the extract containing nanofibers showed a considerable inflammation reduction at day 14. Additionally, this group showed more resemblance to normal skin with a thin epidermis presence of normal rete ridges and rejuvenation of skin appendages. Neovascularization and collagen deposition were higher in wounds treated with the extract containing nanofibrous wound dressing compared to the other groups.

Argon and Argon-Oxygen Plasma Surface Modification of Gelatin Nanofibers for Tissue Engineering Applications

In the present study, we developed a novel approach for functionalization of gelatin nanofibers using the plasma method for tissue engineering applications. For this purpose, tannic acid-crosslinked gelatin nanofibers were fabricated with electrospinning, followed by treatment with argon and argon–oxygen plasmas in a vacuum chamber. Samples were evaluated by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle (CA) and X-ray diffraction (XRD). The biological activity of plasma treated gelatin nanofibers were further investigated by using fibroblasts as cell models. SEM studies showed that the average diameter and the surface morphology of nanofibers did not change after plasma treatment. However, the mean surface roughness (RMS) of samples were increased due to plasma activation. ATR-FTIR spectroscopy demonstrated several new bands on plasma treated fibers related to the plasma ionization of nanofibers. The CA test results stated that the surface of nanofibers became completely hydrophilic after argon–oxygen plasma treatment. Finally, increasing the polarity of crosslinked gelatin after plasma treatment resulted in an increase of the number of fibroblast cells. Overall, results expressed that our developed method could open new insights into the application of the plasma process for functionalization of biomedical scaffolds. Moreover, the cooperative interplay between gelatin biomaterials and argon/argon–oxygen plasmas discovered a key composition showing promising biocompatibility towards biological cells. Therefore, we strongly recommend plasma surface modification of nanofiber scaffolds as a pretreatment process for tissue engineering applications.

Nano-engineered Adsorbent for the Removal of Dyes from Water: A Review

Background:

The huge quantity of wastewater, containing poisonous and hazardous dyes, is released by various industries which pollute water in direct and indirect ways. Most of the dyes are a dangerous class of water contaminants which have affected the environment drastically. Some dyes such as congo red, rhodamine B, methylene blue, methyl violet, and crystal violet are a serious threat to human beings.

Remediation Method:

Numerous methods are available for the removal of dyes from water. Adsorption, being a superior and eco-friendly technique, has advantage of eliminating organic dyes because of the availability of materials as adsorbents. The inexpensive nanomaterials are a more attractive choice for remediation of various dyes due to their unique properties and offer an adequate pathway to adsorb any organic dye from water to overcome its hazardous effects on human health.

Results:

In this review, we have discussed the latest literature related to various types of synthesis, characterization and uses as adsorbent for highly adsorptive removal capacity of nanoparticles for organic dyes.

Conclusion:

Adsorption technology provides an attractive pathway for further research and improvement in more efficient nanoparticles, with higher adsorption capacity, for numerous dyes to eliminate the dyes discharged from various industries and thus reduce the contamination of water. Therefore, nanocomposites may contribute to future prospective water treatment process.

Strong enhancement of methylene blue removal from binary wastewater by in-situ ferrite process

Dye wastewater containing heavy metal ions is a common industrial effluent with complex physicochemical properties. The treatment of metal-dye binary wastewater is difficult. In this work, a novel in-situ ferrite process (IFP) was applied to treat Methylene Blue (MB)-Cu(II) binary wastewater, and the operational parameters were optimized for MB removal. Results showed that the optimum operating conditions were OH/M of 1.72, Cu²⁺/Fe²⁺ ratio of 1/2.5, reaction time of 90min, aeration intensity of 320mL/min, and reaction temperature of 40°C. Moreover, the presence of Ca²⁺ and Mg²⁺ moderately influenced the MB removal. Physical characterization results indicated that the precipitates yielded in IFP presented high surface area (232.50m²/g) and a multi-porous structure. Based on the Langmuir model, the maximum adsorption capacity toward MB was 347.82mg/g for the precipitates produced in IFP, which outperformed most other adsorbents. Furthermore, IFP rapidly sequestered MB with removal efficiency 5 to 10 times greater than that by general ferrite adsorption, which suggested a strong enhancement of MB removal by IFP. The MB removal process by IFP showed two different high removal stages, each with a corresponding removal mechanism. In the first brief stage (<5min), the initial high MB removal (~95%) was achieved by predominantly electrostatic interactions. Then the sweep effect and encapsulation were dominant in the second longer stage.

Efficient removal of Acid Green 25 dye from wastewater using activated Prunus Dulcis as biosorbent: Batch and column studies

Biosorbent synthesized from dead leaves of Prunus Dulcis with chemical activation during the synthesis was applied for the removal of Acid Green 25 dye from wastewater. The obtained biosorbent was characterized using Brunauer-Emmett-Teller analysis, Fourier transform-infrared spectroscopy and scanning electron microscopy measurements. It was demonstrated that alkali treatment during the synthesis significantly increased surface area of biosorbent from 67.205 to 426.346 m²/g. The effect of various operating parameters on dye removal was investigated in batch operation and optimum values of parameters were established as pH of 2, 14 g/L as the dose of natural biosorbent and 6 g/L as the dose of alkali treated biosorbent. Relative error values were determined to check fitting of obtained data to the different kinetic and isotherm models. It was established that pseudo-second order kinetic model and Langmuir isotherm fitted suitably to the obtained batch experimental data. Maximum biosorption capacity values were estimated as 22.68 and 50.79 mg/g for natural biosorbent and for alkali activated Prunus Dulcis, respectively. Adsorption was observed as endothermic and activation energy of 6.22 kJ/mol confirmed physical type of adsorption. Column experiments were also conducted to probe the effectiveness of biosorbent for practical applications in continuous operation. Breakthrough parameters were established by studying the effect of biosorbent height, flow rate of dye solution and initial dye concentration on the extent of dye removal. The maximum biosorption capacity under optimized conditions in the column operation was estimated as 28.57 mg/g. Thomas and Yoon-Nelson models were found to be suitably fitted to obtained column data. Reusability study carried out in batch and continuous column operations confirmed that synthesized biosorbent can be used repeatedly for dye removal from wastewater.

Mesoporous MgO/PPG hybrid nanofibers: synthesis, optimization, characterization and heavy metal removal property

In this research, mesoporous magnesium oxide/poly(propylene glycol) (MgO/PPG) hybrid nanofibers were synthesized as a new adsorbent for the removal of heavy metal ions from solutions.

Emergence of bismuth substituted cobalt ferrite nanostructures as versatile candidates for the enhanced oxidative degradation of hazardous organic dyes

The dramatic enhancement in the catalytic performance with the incorporation of 1% bismuth into the cobalt ferrite lattice has been scrutinized for the oxidative degradation of hazardous dyes.