Enhanced photocatalytic activity of modified black phosphorus-incorporated PANi/PAN nanofibers.

Enhancement of the photocatalytic activity of black phosphorus (BP) is a highly challenging proposition. The fabrication of electrospun composite nanofibers (NFs) through the incorporation of modified BP nanosheets (BPNs) into conductive polymeric NFs has been recently introduced as a newer strategy not only to enhance the photocatalytic activity of BPNs but also to overcome their drawbacks including ambient instability, aggregation, and hard recycling, which exist in their nanoscale powdered forms. The proposed composite NFs were prepared through the incorporation of silver (Ag)-modified BPNs, gold (Au)-modified BPNs, and graphene oxide (GO)-modified BPNs into polyaniline/polyacrylonitrile (PANi/PAN) NFs by an electrospinning process. The successful preparation of the modified BPNs and electrospun NFs was confirmed by the characterization techniques of Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis), powder X-ray diffraction (PXRD), and Raman spectroscopy. The pure PANi/PAN NFs exhibited high thermal stability with a main weight loss of ∼23% for the temperature range of 390-500 °C, and the thermal stability of NFs was enhanced after their incorporation with the modified BPNs. The BPNs@GO-incorporated PANi/PAN NFs indicated improved mechanical properties compared to the pure PANi/PAN NFs with tensile strength (TS) of 1.83 MPa and elongation at break (EAB) of 24.91%. The wettability of the composite NFs was measured in the range of 35-36°, which exhibited their good hydrophilicity. The photodegradation performance was found in the sequence of BPNs@GO > BPNs@Au > BPNs@Ag > bulk BP ∼BPNs > red phosphorus (RP) for methyl orange (MO) and in the sequence of BPNs@GO > BPNs@Ag > BPNs@Au > bulk BP > BPNs > RP for methylene blue (MB), accordingly. The composite NFs degraded the MO and MB dyes more efficiently relative to the modified BPNs and pure PANi/PAN NFs.

MOF-based composites as photoluminescence sensing platforms for pesticides: Applications and mechanisms.

Metal-organic frameworks (MOFs) have recently garnered considerable attention among reticular compounds due to their unique physicochemical properties and applications in sensing toxic compounds. On the other hand, fluorometric sensing has been widely studied for food safety and environmental protection among the various sensing methods. Thus, designing MOF-based fluorescence sensors for specific detection of hazardous compounds, especially pesticides, are incessantly needed to keep up with the continuous demands for monitoring these environmental pollution. Herein, recent MOF-based platforms for pesticide fluorescence detection are deliberated owing to sensors' emission origins and in terms of their structural properties. The influences of different guest incorporation in MOFs on pesticide fluorescence detection are summarized, and the future developments of novel MOF composites such as polyoxometalate@MOFs (POMOF), carbon quantum dots@MOFs (CDs@MOF), and organic dye@MOF are prospected for fluorescence sensing of assorted pesticides with a focus on mechanistic insights of specific detection techniques in food safety and environmental protection.

Electrospun composite nanofibers as novel high-performance and visible-light photocatalysts for removal of environmental pollutants: A review.

Environmental pollution caused by industries and human manipulations is coming a serious global challenge. On the other hand, the world is facing an energy crisis caused by population growth. Designing solar-driven photocatalysts which are inspired by the photosynthesis of plant leaves is a fantastic solution to use solar energy as green, available, and unlimited energy containing ∼50% visible light for the removal of environmental pollutants. The polymeric and non-polymeric-based electrospun composite nanofibers (NFs) are as innovative photocatalytic candidates which increase photocatalytic activity and transition from UV light to visible light and overcome the aggregation, photocorrosion, toxicity, and hard recycling and separation of the nanosized powder form of photocatalysts. The composite NFs are fabricated easily by either embedding the photocatalytic agents into the NFs during electrospinning or via their decorating on the surface of NFs post-electrospinning. Polyacrylonitrile-based, tungsten trioxide-based, zinc oxide-based, and titanium dioxide-based composite NFs were revealed as the most reported composite NFs. All the lately investigated electrospun composite NFs indicated long-term stability, high photocatalytic efficiency (∼> 80%) within a short time of light radiation (10-430 min), and high stability after several cycles of use. They were applied in various applications including degradation of dyes/antibiotics, water splitting, wastewater treatment, antibacterial usage, etc. The photogenerated species especially holes, O2∙-, and .OH were mostly responsible for the photocatalytic mechanism and pathway. The electrospun composite NFs have the potential to use in large-scale productions in condition that their thickness and recycling conditions are optimized, and their toxicity and detaching are resolved.

Electrospun Ag-decorated reduced GO-graft-chitosan composite nanofibers with visible light photocatalytic activity for antibacterial performance.

The treatment of water contaminated by bacteria is becoming a necessity. The nanomaterials possessing both intrinsic antibacterial properties and photocatalytic activity are excellent candidates for water disinfection. The powdered form of nanomaterials can be aggregated while embedding the nanomaterials into the NFs can overcome the limitation and enhance the photocatalytic activity and transition from UV-light to visiblelight. Here, graphene oxide (GO) was synthesized, grafted to chitosan, and decorated with silver nanoparticles (Ag NPs) to produce Ag-decorated reduced GO-graft-Chitosan (AGC) NPs. The blends of polyacrylonitrile (PAN) and AGC NPs were prepared in various concentrations of 0.5 wt%, 1.0 wt%, 5.0 wt%, and 10.0 wt% and used to fabricate the electrospun composite NFs. FTIR/ATR, UV-Vis, Raman, XRD, and SEM/EDAX analyses confirmed the successful preparation of the NPs and NFs. The cytotoxicity and antibacterial activity of the composite NFs were received in the order of composite NFs 10.0 wt%˃ 5.0 wt%˃ 1.0 wt%˃ 0.5 wt% in both conditions with/without light irradiation. Their cytotoxicity and antibacterial activity were more under light irradiation compared to the dark. The composite NFs (5.0 wt%) were distinguished as the optimum NFs with cell viability of 80% within 24 h and 60% within 48 h on L929 cells and inhibition zone diameter (IZD) of 12 mm for E. coli and 13 mm for S. aureus after 24 h under the light irradiation. The optimum composite NFs showed thermal stability up to 180 °C and tensile strength of 1.11 MPa with 21.71% elongation at break.

Polymeric carriers for enhanced delivery of probiotics.

Probiotics are live microorganisms (usually bacteria), which are defined by their ability to confer health benefits to the host, if administered adequately. Probiotics are not only used as health supplements but have also been applied in various attempts to prevent and treat gastrointestinal (GI) and non-gastrointestinal diseases such as diarrhea, colon cancer, obesity, diabetes, and inflammation. One of the challenges in the use of probiotics is putative loss of viability by the time of administration. It can be due to procedures that the probiotic products go through during fabrication, storage, or administration. Biocompatible and biodegradable polymers with specific moieties or pH/enzyme sensitivity have shown great potential as carriers of the bacteria for 1) better viability, 2) longer storage times, 3) preservation from the aggressive environment in the stomach and 4) topographically targeted delivery of probiotics. In this review, we focus on polymeric carriers and the procedures applied for encapsulation of the probiotics into them. At the end, some novel methods for specific probiotic delivery, possibilities to improve the targeted delivery of probiotics and some challenges are discussed.

The effect of inhalation aromatherapy with damask rose essence on pain intensity and anxiety in burned patients: A single-blind randomized clinical trial.

INTRODUCTION: Pain and anxiety are a major problem of burn patients. Despite the use of different medications, patients still suffer from these two problems. Aromatherapy along with medication may help in alleviating these symptoms. This study aimed to investigate the effect of inhalation aromatherapy with damask rose essence on pain and anxiety in burn patients. METHODS: This three group clinical trial was conducted on 120 patients with burns less than 30% TBSA. The patients were randomly allocated into three groups, aromatherapy damask rose essence, placebo, and control. The pain intensity was assessed using visual analogue scale prior to intervention, immediately before, and 15 min after dressing. Anxiety was measured using Spielberger Inventory at before intervention and 15 min after dressing, also the prolonged effect of intervention on pain was assessed by number of the analgesics drugs received for four hours after dressing change. The intervention included inhalation of 6 drops of 40% damask rose essential oil in the damask group, and six drops of distilled water in placebo group one hour before dressing change. The control group received no intervention. RESULTS: Baseline state-trait anxiety and pain intensity were similar in these three groups (p > 0.05). We found a significant reduction in pain intensity immediately before and after dressing and state anxiety after dressing in the damask group compared to the placebo and control groups (p < 0.001). However, we found no significant difference between the placebo and control groups in terms of these variables at these times (p > 0.05). Also, we found no significant difference among three groups in frequency of analgesics drugs and trait anxiety after intervention (p > 0.05). CONCLUSION: Inhaled aromatherapy with Damask rose essence reduces subjective pain intensity and state anxiety in burned patients. Therefore, it is recommended considering use of damask rose essence, as an easy and affordable method along with other treatments.

A pH-sensitive carrier based-on modified hollow mesoporous carbon nanospheres with calcium-latched gate for drug delivery.

A novel nanocarrier based-on hollow mesoporous carbon nanospheres (HMCNs) with primary amines on its surface, a large cavity, and good hydrophilicity was synthesized by a hydrothermal reaction. The primary amine functionalities on the mesoporous carbon were used as the initiation sites for growing poly (epichlorohydrin) (PCH) chains. The chlorine groups in the side chain of PCH were replaced with imidazole as the pendant groups. Calcium chloride (CaCl2) was applied as a capping agent. The coordination bonding was formed between pendant imidazole groups and calcium ions. Doxorubicin (DOX) was selected as a model of hydrophilic anticancer drug and was loaded onto the nanocarrier and released through the cleavage of the pH-sensitive coordination bonding. The gating mechanism enables the nanocarrier to store and release the calcium ions and the DOX molecules trapped in the pores. MTT assay toward HeLa cells indicated that the nanocarrier had low toxicity because of the surface modification with the oxygen-rich polymer. The cellular uptake of the pH-sensitive nanocarrier for HeLa cancer cell lines was confirmed by CLSM images and flow cytometry. So, the novel pH-sensitive nanocarrier can be applicable to carry and release both DOX drug and calcium ions for cancer treatment.

Codelivery of Hydrophobic and Hydrophilic Drugs by Graphene-Decorated Magnetic Dendrimers.

In this study, a nanocarrier was prepared for the codelivery of a hydrophilic drug (doxorubicin) and a hydrophobic drug (curcumin) to cancer cells. In this nanocarrier, the edges of graphene oxide sheets were decorated with a magnetic-functionalized polyamidoamine dendrimer with hydrazone groups at the end of the polymer. The edge functionalization of graphene sheets not only improved the solubility and dispersibility of graphene sheets but also imparted the magnetic properties to the nanocarrier. The resulting nanocarrier was loaded with doxorubicin through the covalent linkage and curcumin through π-π stacking. The nanocarrier showed a pH-sensitive release for both drugs, and the drug release behavior was also improved by the coimmobilization of both drugs. The cytotoxicity assay of nanocarrier showed low toxicity toward MCF-7 cell compared to unmodified graphene oxide, which was attributed to the presence of a magnetic dendrimer. Besides, the drug-loaded nanocarrier was highly toxic for cells even more than for free drugs. The cellular uptake images revealed higher drug internalization for coloaded nanocarrier than for the nanocarrier loaded with one drug alone. All of the results showed that the codelivery of curcumin and doxorubicin in the presence of the nanocarrier was more effective in chemotherapy than the nanocarrier loaded with one drug.