Alginate hydrogel-PCL/gelatin nanofibers composite scaffold containing mesenchymal stem cells-derived exosomes sustain release for regeneration of tympanic membrane perforation

Exosomes are among the most effective therapeutic tools for tissue engineering. This study demonstrates that a 3D composite scaffold containing exosomes can promote regeneration in rat tympanic membrane perforation (TMP). The scaffolds were characterized using scanning electron microscopy (SEM), degradation, PBS adsorption, swelling, porosity, and mechanical properties. To confirm the isolation of exosomes from human adipose-derived mesenchymal stem cells (hAMSCs), western blot, SEM, and dynamic light scattering (DLS) were performed. The Western blot test confirmed the presence of exosomal surface markers CD9, CD81, and CD63. The SEM test revealed that the isolated exosomes had a spherical shape, while the DLS test indicated an average diameter of 82.5 nm for these spherical particles. MTT assays were conducted to optimize the concentration of hAMSCs-exosomes in the hydrogel layer of the composite. Exosomes were extracted on days 3 and 7 from an alginate hydrogel containing 100 and 200 μg/mL of exosomes, with 100 μg/mL identified as the optimal value. The optimized composite scaffold demonstrated improved growth and migration of fibroblast cells. Animal studies showed complete tympanic membrane regeneration (TM) after five days. These results illustrate that a scaffold containing hAMSC-exosomes can serve as an appropriate tissue-engineered scaffold for enhancing TM regeneration.

A green approach for preparation of chitosan/hydroxyapatite/graphitic carbon nitride hydrogel nanocomposite for improved 5-FU delivery

Reducing the side effects of cancer treatment methods is an important issue. The loading efficiency and sustained release of 5-Fluorouracil (5-FU) have been significantly improved by creating a new method. A nanocarrier with pH sensitivity has been developed through the w/o/w emulsification method. It is loaded with 5-FU and comprises of chitosan (CS), hydroxyapatite (HAp), and graphitic carbon nitride (g-C3N4). g-C3N4 nanosheets were incorporated in CS/HAp hydrogel to improve the entrapment and loading efficiency. Drug loading efficiency and entrapment efficiency reached 48 % and 87 %, respectively, and the FTIR and XRD tests verified evidence of the formation of chemical bonds among the drug and nanocarrier. Structural analysis was done using FE-SEM. DLS and zeta potential were employed to obtain average size distribution and surface charge. The release profile of 5-FU in various conditions shows the nanoparticles' pH dependence, and the nanocomposite's controlled release is consistent with the Korsmeyer-Peppas kinetic model. Cell apoptosis and cytotoxicity were evaluated in vitro using flow cytometry and MTT analysis. The biocompatibility of CS/HAp/g-C3N4 against MCF-7 cells was shown by the MTT method and confirmed by flow cytometry. CS/HAp/g-C3N4@5-FU led to the highest apoptosis rate in MCF-7 cells, indicating the nanocarrier's efficiency in killing cancer cells. These data indicate that the designed CS/HAp/g-C3N4@5-FU can be a potential drug for treating cancer cells.

Preparation and characterization of 3D bioprinted gelatin methacrylate hydrogel incorporated with curcumin loaded chitosan nanoparticles for in vivo wound healing application

This study developed a biomimetic composite bioink consisting of gelatin methacrylate (GelMA) /chitosan nanoparticles (CSNPs) for extrusion-based 3D bioprinting. Additionally, curcumin(Cur)-loaded nanoparticles were incorporated which increased the proliferation and antibacterial activity of biomimetic skin constructs. The hydrogel, curcumin-loaded NPs, and the biocomposite was characterized chemically and physically. The results indicated proper modified gelatin with tunable physical characteristics, e.g., swelling ratio and biodegradability up to 1200 % and 25 days, respectively. In addition, the characterized CSNPs showed good distribution with a size of 370 nm and a zeta potential of 41.1 mV. We investigated the mechanical and cytocompatibility properties of chitosan nanoparticles encapsulated in hydrogel for emulating an extracellular matrix suitable for skin tissue engineering. CSNPs entrapped in GelMA (15 % w/v) exhibited controlled drug release during 5 days, which was fitted into various kinetic models to study the mass transfer mechanism behavior. Also, the composite hydrogels were effective as a barrier against both gram-positive and gram-negative bacteria at a concentration of 50 μg/ml nanoparticles in GelMA 15 %. Furthermore, the biocomposite was applied on Wistar rats for wound healing. As a result, this study provides a GelMA-NP50-Cur3 scaffold that promotes cell proliferation and decreases microbial infections in wounds.

Fabrication and optimization of multilayered composite scaffold made of sulfated alginate-based nanofiber/decellularized Wharton's jelly ECM for tympanic membrane tissue engineering

In this study, we fabricated a novel multilayer polyvinyl alcohol (PVA)/alginate sulfate (ALG-S) nanofiber/decellularized Wharton's Jelly ECM (d-ECM) composite for tympanic membrane perforations (TMPs) tissue engineering (TE). Initially, electrospun PVA/ALG-S scaffolds with different blend ratios were fabricated. The influence of ALG-S ratio on surface morphology, mechanical, physical and biological properties of the nanofibers was studied. Secondly, 3-layer composites were developed as a combination of PVA/ALG-S nanofibers and d-ECM to take synergic advantages of electrospun mats and d-ECM. As part of the evaluation of the effects of d-ECM incorporation, the composite's mechanical properties, in vitro degradation, swelling ratio, and biological activities were assessed. The MTT assay showed that PVA/ALG-S nanofibers with 50:50 ratio provided a more desirable environment to support cell growth. A composite containing 25 mg/cm2 d-ECM was determined as the optimal composite through MTT assay, and this composite was used for animal studies inducing TMP regeneration. According to the in vivo studies, the optimal composite not only stimulated the healing of TMPs but also shortened the healing period. These results suggest that a multilayer nanofiber/hydrogel composite could be a potential platform for regenerating TMPs.

Preparation and characterization of pH-sensitive chitosan/starch/MoS2 nanocomposite for control release of curcumin macromolecules drug delivery; application in the breast cancer treatment

In this work, chitosan (CS), Starch (S), and Molybdenum Disulfide (MoS2) were combined to create a nanocarrier that was utilized to treat breast cancer using the MCF-7 cell line. To analyze the features of the nanocarrier, Fourier-transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD) tests were performed, respectively, to discover physical interactions and chemical bonding. Field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), and zeta potential analyses were performed and reported to determine the structural characteristics and morphology of nanoparticles, size distribution, and surface charge of nanocarriers, respectively. The average size of the nanocomposite was measured at around 279 nm, and the surface charge of the nanocarrier was determined to be +86.31 mV. The entrapment and drug loading efficiency of nanocarriers were 87.25 % and 46.5 %, respectively, which is an acceptable value. The kinetics and release mode of the drug were investigated, and it was found that the synthesized nanocarrier was sensitive to pH and that its release was stable. The amount of the nanocarriers' toxicity and cell death were evaluated using MTT tests and flow cytometry, respectively. In the present study, the nanocarrier was wholly nontoxic and had anticancer properties against the MCF-7 cell line. This nanocarrier is very important due to its non-toxicity and sensitivity to pH and can be used in drug delivery and medical applications.

Synthesis and characterization of chitosan/carbon quantum dots/Fe2O3 nanocomposite comprising curcumin for targeted drug delivery in breast cancer therapy

Curcumin, a natural compound with promising anti-cancerous features, suffers from a number of shortcomings such as low chemical stability, bioavailability, and solubility, which impedes its application as an alternative for conventional cancer therapy. In this study, curcumin comprising Fe2O3/Chitosan/CQDs was fabricated through double emulsion method (W/O/W) for the first time to exploit its anticancer features while alleviating its limitation, making this nanocomposite promising in targeted drug delivery. Chitosan, a hydrophilic biopolymer, has incorporated to constitute an adhesive pH-sensitive matrix that can trap the hydrophobic drug resulting in controlled drug release in cancerous environment. Carbon quantum dots render luminescence and water solubility properties, which is favorable for tracing drug release and bio imaging along with enhancement of biocompatibility. Fe2O3 can improve chemical stability and bioavailability in addition to anti-cancerous property. XRD and FTIR analysis confirmed the physical interaction between the drug and fabricated nano composite in addition to chemical bonding between the prepared nano composite. Matrix and spherical structure of the formed drug is corroborated by FESEM analysis. DLS analysis' results determine the mean size of the nano composite at about 227.2 nm and zeta potential result is indicative of perfect stability of the fabricated drug. Various kinetic models for drug release were fitted to experimental data in order to investigate the drug release in which Korsmeyer-Peppas' model was the predominant release system in cancerous environment. In vitro studies through flow cytometry and MTT assay exerted noticeable cytotoxicity effect on MCF-7 cell lines. It can be deduced from these results that curcumin encapsulated with CS/CQDs/Fe2O3 nanocomposites is an excellent alternative for targeted drug delivery.

Targeted Anticancer Drug Delivery Using Chitosan, Carbon Quantum Dots, and Aptamers to Deliver Ganoderic Acid and 5-Fluorouracil

Breast cancer is a malignancy that affects mostly females and is among the most lethal types of cancer. The ligand-functionalized nanoparticles used in the nano-drug delivery system offer enormous potential for cancer treatments. This work devised a promising approach to increase drug loading efficacy and produce sustained release of 5-fluorouracil (5-FU) and Ganoderic acid (GA) as model drugs for breast cancer. Chitosan, aptamer, and carbon quantum dot (CS/Apt/COQ) hydrogels were initially synthesized as a pH-sensitive and biocompatible delivery system. Then, CS/Apt/COQ NPs loaded with 5-FU-GA were made using the W/O/W emulsification method. FT-IR, XRD, DLS, zeta potentiometer, and SEM were used to analyze NP's chemical structure, particle size, and shape. Cell viability was measured using MTT assays in vitro using the MCF-7 cell lines. Real-time PCR measured cell apoptotic gene expression. XRD and FT-IR investigations validated nanocarrier production and revealed their crystalline structure and molecular interactions. DLS showed that nanocarriers include NPs with an average size of 250.6 nm and PDI of 0.057. SEM showed their spherical form, and zeta potential studies showed an average surface charge of +37.8 mV. pH 5.4 had a highly effective and prolonged drug release profile, releasing virtually all 5-FU and GA in 48 h. Entrapment efficiency percentages for 5-FU and GA were 84.7±5.2 and 80.2 %±2.3, respectively. The 5-FU-GA-CS-CQD-Apt group induced the highest cell death, with just 57.9 % of the MCF-7 cells surviving following treatment. 5-FU and GA in CS-CQD-Apt enhanced apoptotic induction by flow cytometry. 5-FU-GA-CS-CQD-Apt also elevated Caspase 9 and downregulated Bcl2. Accordingly, the produced NPs may serve as pH-sensitive nano vehicles for the controlled release of 5-FU and GA in treating breast cancer.

P3HB from CH4 using methanotrophs: aspects of bioreactor, fermentation process and modelling for cost-effective biopolymer production

P3HB (poly-β-hydroxybutyrate), an energy-storage compound of several microorganisms, can be used as bioplastics material. P3HB is completely biodegradable under aerobic and aerobic conditions, also in the marine environment. The intracellular agglomeration of P3HB was examined employing a methanotrophic consortium. Supplanting fossil, non-degradable polymers by P3HB can significantly reduce the environmental impact of plastics. Utilizing inexpensive carbon sources like CH₄ (natural gas, biogas) is a fundamental methodology to make P3HB production less costly, and to avoid the use of primary agricultural products such as sugar or starch. Biomass growth in polyhydroxyalkanoates (PHA) in general and in Poly (3-hydroxybutyrate) manufacture in specific could be a foremost point, so here the authors focus on natural gas as a proper carbon source and on the selection of bioreactors to produceP3HB, and in future further PHA, from that substrate. CH₄ can also be obtained from biomass, e.g., biogas, syngas methanation or power-to-gas (synthetic natural gas, SNG). Simulation software can be utilized for examination, optimizing and scale-up of the process as shown in this paper. The fermentation systems continuously stirred tank reactor (CSTR), forced-liquid vertical loop bioreactor (VTLB), forced-liquid horizontal tubular loop bioreactor (HTLB), airlift (AL) fermenter and bubble column (BC) fermenter were compared for their methane conversion, kLa value, productivity, advantages and disadvantages. Methane is compared to methanol and other feedstocks. It was discovered that under optimum processing circumstances and using Methylocystis hirsuta, the cells accumulated 51.6% cell dry mass of P3HB in the VTLB setup.

Green synthesis of chitosan/polyacrylic acid/graphitic carbon nitride nanocarrier as a potential pH-sensitive system for curcumin delivery to MCF-7 breast cancer cells

A novel pH-sensitive nanocarrier containing chitosan (CS), polyacrylic acid (PAA), and graphitic carbon nitride (g-C₃N₄) was designed via water/oil/water (W/O/W) emulsification to administer curcumin (CUR) drug. g-C₃N₄ nanosheets with a high surface area and porous structure were produced via simple one-step pyrolysis process using thiourea as precursor, and incorporated into CS/PAA hydrogel. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to assess the crystalline structure of the nanocarrier and the interactions between its components, respectively. Scanning electron microscopy (SEM) images revealed a spherical structure and confirmed the g-C₃N₄ impregnation into the CS/PAA matrix. Zeta potential and dynamic light scattering (DLS) provided information about the surface charge and average size distribution. High CUR loading and entrapment efficiencies were obtained, which were further improved upon addition of g-C₃N₄. The release kinetics of drug-loaded CS/PAA/g-C₃N₄ nanocomposites were investigated at pH = 5.4 and pH = 7.4, and the results showed an excellent controlled pH-sensitive release profile. Cell apoptosis and in vitro cytotoxicity were investigated using flow cytometry and MTT analyses. CS/PAA/g-C₃N₄/CUR resulted in the highest rate of apoptosis in MCF-7 breast cancer cells, demonstrating the excellent nanocomposite efficacy in eliminating cancerous cells. CS/PAA hydrogel coated with g-C₃N₄ shows great potential for pH-sensitive controlled drug release.

Carboxymethyl cellulose/starch/reduced graphene oxide composite as a pH-sensitive nanocarrier for curcumin drug delivery

Nanocomposites are promising drug carriers to treat terminal cancers with few adverse effects. Herein, nanocomposite hydrogels composed of carboxymethyl cellulose (CMC)/starch/reduced graphene oxide (RGO) were synthesized via a green chemistry approach and then encapsulated in double nanoemulsions to act as pH-responsive delivery systems for curcumin, a potential antitumor drug. A water/oil/water nanoemulsion containing bitter almond oil served as a membrane surrounding the nanocarrier to control drug release. DLS and zeta potential measurements were used to estimate the size and confirm the stability of curcumin-loaded nanocarriers. The intermolecular interactions, crystalline structure and morphology of the nanocarriers were analyzed through FTIR spectroscopy, XRD and FESEM, respectively. The drug loading and entrapment efficiencies were significantly improved compared to previously reported curcumin delivery systems. In vitro release experiments demonstrated the pH-responsiveness of the nanocarriers and the faster curcumin release at a lower pH. The MTT assay revealed the increased toxicity of the nanocomposites against MCF-7 cancer cells compared to CMC, CMC/RGO or free curcumin. Apoptosis was detected in MCF-7 cells via flow cytometry tests. The results obtained herein support that the developed nanocarriers are stable, uniform and effective delivery systems for a sustained and pH-sensitive curcumin release.

Green synthesized polyvinylpyrrolidone/titanium dioxide hydrogel nanocomposite modified with agarose macromolecules for sustained and pH-responsive release of anticancer drug

Cancer, as one of the most challenging diseases of the last century, has a significant number of patients and deaths every year. Various strategies have been explored for the treatment of cancer. Chemotherapy is one of the methods of treating cancer. Doxorubicin is one of the compounds used in chemotherapy to kill cancer cells. Due to their unique properties and low toxicity, metal oxide nanoparticles are effective in combination therapy and increase the effectiveness of anti-cancer compounds. The limited in vivo circulatory period, poor solubility, and inadequate penetration of doxorubicin (DOX) restrict its use in cancer treatment, notwithstanding its attractive characteristics. It is possible to circumvent some of the difficulties in cancer therapy by using green synthesized pH-responsive nanocomposite consisting of polyvinylpyrrolidone (PVP), titanium dioxide (TiO₂) modified with agarose (Ag) macromolecules. TiO₂ incorporation into the PVP-Ag nanocomposite resulted in limited increased loading and encapsulation efficiencies from 41 % to 47 % and 84 % to 88.5 %, respectively. DOX diffusion among normal cells is prevented by the PVP-Ag-TiO₂ nanocarrier at pH = 7.4, though the acidic intracellular microenvironments activate the PVP-Ag-TiO₂ nanocarrier at pH = 5.4. Characterization of the nanocarrier was performed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrophotometry, field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), and zeta potential. The average particle size and the zeta potential of the particles showed values of 349.8 nm and +57 mV, respectively. In vitro release after 96 h showed a release rate of 92 % at pH 7.4 and a release rate of 96 % at pH 5.4. Meanwhile, the initial release after 24 h was 42 % for pH 7.4 and 76 % for pH 5.4. As shown by an MTT analysis on MCF-7 cells, the toxicity of DOX-loaded PVP-Ag-TiO₂ nanocomposite was substantially greater than that of unbound DOX and PVP-Ag-TiO₂. After integrating TiO₂ nanomaterials into the PVP-Ag-DOX nanocarrier, flow cytometry data showed a greater stimulation of cell death. These data indicate that the DOX-loaded nanocomposite is a suitable alternative for drug delivery systems.

Nanoemulsion carriers of porous γ-alumina modified by polyvinylpyrrolidone and carboxymethyl cellulose for pH-sensitive delivery of 5-fluorouracil

5-Fluorouracil (5-FU) is a cytotoxic drug with a low half-life. These features can cause some problems such as burst drug release and numerous side effects. In the present study, a pH-sensitive nanocomposite of polyvinylpyrrolidone (PVP)/carboxymethyl cellulose (CMC)/γ-alumina developed by using water in oil in water (W/O/W) double emulsion method. The fabricated emulsion has been employed as the 5-FU carrier to investigate its effects on drug half-life, side effects, drug loading efficiency (DLE), and drug entrapment efficiency (DEE). Analyzing the FTIR and XRD indicated the successful loading of 5-FU into the nanocarrier and affirmed the synthesized nanocomposite's chemical bonding and crystalline features. Furthermore, by using DLS and Zeta potential assessment, size and undersize distribution, as well as the stability of the drug-loaded nanocomposite were determined, which demonstrated the monodisperse and stable nanoparticles. Moreover, the nanocomposites with spherical shapes and homogeneous surfaces were shown in FE-SEM, which indicated good compatibility for the constituents of the nanocomposites. Moreover, by employing BET analysis the porosity has been investigated. Drug release pattern was studied, which indicated a controlled drug release behavior with above 96 h drug retention. Besides, the loading and entrapment efficiencies were obtained 44 % and 86 %, respectively. Furthermore, the curve fitting technique has been employed and the predominant release mechanism has been determined to evaluate the best-fitted kinetic models. MTT assay and flow cytometry assessment has been carried out to investigate the cytotoxic effects of the fabricated drug-loaded nanocomposite on MCF-7 and normal cells. The results showed enhanced cytotoxicity and late apoptosis for the PVP/CMC/γ-alumina/5-FU. Based on the MTT assay outcomes on normal cell lines (L929), which indicated above 90 % cell viability, the biocompatibility and biosafety of the synthesized nanocarrier have been confirmed. Moreover, due to the porosity of the PVP/CMC/γ-alumina, this nanocarrier can exploit from high specific surface area and be more sensitive to environmental conditions such as pH. These outcomes propose that the novel pH-sensitive PVP/CMC/γ-alumina nanocomposite can be a potential candidate for drug delivery applications, especially for cancer therapy.

Novel carboxymethyl cellulose-halloysite-polyethylene glycol nanocomposite for improved 5-FU delivery

Drug nano-carriers are crucial for achieving targeted treatment against cancer disorders with minimal side effects. In this study, a pH-responsive nanocomposite based on halloysite nanotube (HNT) coated with carboxymethyl cellulose (CMC)/polyethylene glycol (PEG) hydrogel for controlled delivery of 5-Fluorouracil (5-FU), a hydrophobic chemotherapy drug prescribed for different types of cancers was synthesized for the first time using the water-in-oil-in-water (W/O/W) technique. The developed CMC/PEG/HNT/5-FU nanocomposite was characterized by dynamic light scattering (DLS), zeta potential, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Field emission scanning electron microscope (FE-SEM) to get information about the particle size, surface charge, interactions between functional groups, crystalline structure and morphology, respectively. High efficiencies in terms of drug entrapment and loading (46 % and 87 %, respectively) were attained. In-vitro drug release results revealed an improved and sustained 5-FU delivery in an acid environment compared to the physiological medium, corroborating the pH-sensitivity of the developed nano-carrier. Flow cytometry and MTT assays demonstrated that the 5-FU loaded nanocomposite had considerable cytotoxicity on MCF-7 breast cancer cells while it is not toxic against L929 fibroblast cells. The nanocomposite synthesized herein could serve as a platform for the pH-sensitive release of anti-cancer drugs.

Biocompatibility evaluation of polyethersulfone-pyrolytic carbon composite membrane in artificial pancreas

Polyethersulfone (PES) membranes are widely used in medical devices, especially intravascular devices such as intravascular bioartificial pancreases. In the current work, the pure PES and PES-pyrolytic carbon (PyC) composite membranes were synthesized and permeability studies were conducted. In addition, the cytocompatibility and hemocompatibility of the pure PES and PES-PyC membranes were investigated. These materials were characterized using peripheral blood mononuclear cell (PBMC) activation, platelet activation, platelet adhesion, ß-cell viability and proliferation, and ß-cell response to hyperglycemia. The results showed that platelet activation decreased from 87.3% to 27.8%. Any alteration in the morphology of sticking platelets was prevented, and the number of attached platelets decreased by modification with PyC. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay corroborated that PBMC activation was encouraged by the PyC-modified PES membrane surface. It can be concluded that PES-modified membranes show higher hemocompatibility than pure PES membranes. ß-cells cultured on all the three membranes displayed a lower rate of proliferation although the cells on the PES-PyC (0.1 wt. %) membrane indicated a slightly higher viability and proliferation than those on the pure PES and PES-PyC (0.05 wt. %) membranes. It shows that the PES-PyC (0.1 wt. %) membrane possesses superior cytocompatibility over the other membranes.

Optimization of electrospun CQDs-Fe3O4-RE loaded PVA-cellulose nanofibrils via central composite design for wound dressing applications: Kinetics and in vitro release study

Wound skin infections can cause significant morbidity and even mortality. Cellulose nanofibrils (CNFs) are a type of nano cellulose that have reached notable attention due to their inimitable properties. In this study, in order to prepare a novel wound dressing, CNFs are composited with poly (vinyl alcohol) (PVA) to enhance mechanical properties and increase cell proliferation and migration. Also, carbon quantum dots (CQDs)- Fe₃O₄ was introduced as a novel antibacterial, and rosemary extract (RE) was composited with this to reduce its cell toxicity. PVA - CNFs/ CQDs- Fe₃O₄- RE nanofiber was prepared using the electrospinning method. Then, to maximize tensile strength, total elongation, and percentage swelling of PVA - CNFs/ CQDs- Fe₃O₄- RE electrospun nanofiber, parameters of crosslinking duration and the concentration of CQDs- Fe₃O₄-RE were optimized employing central composite design, and optimized electrospun nanofiber (OEN) as a novel wound dressing was prepared. Results exhibited, the high antibacterial properties of CQDs-Fe₃O₄-RE. Also, CNFs and CQDs- Fe₃O₄-RE increased the tensile strength of OEN. Moreover, CNFs and RE reduce wound area percentages and increase the percentage of cell viability, respectively. Therefore, OEN was introduced as a suitable wound dressing due to its appropriate surface roughness, mechanical properties, WVTR, biodegradation, prolonged release, non-toxicity, and high cell proliferation and migration ability.

Chitosan/silk fibroin/nitrogen-doped carbon quantum dot/α-tricalcium phosphate nanocomposite electrospinned as a scaffold for wound healing application: In vitro and in vivo studies

A highly porous nanofibrous network that can functionalize antibacterial and therapeutic agents can be considered a suitable option for skin wound healing. In this study, α-tricalcium phosphate (α-TCP)/nitrogen-doped carbon quantum dots (N-CQDs) nanocomposite was synthesized and then applied to the fabrication of novel chitosan (CS)/silk fibroin (SF)/N-CQDs/α-TCP wound dressing via electrospinning system. The prepared nanomaterials were well characterized using X-ray diffraction, Fourier-transform infrared, scanning and transmission electron microscopes analyses, and antibacterial assay. Furthermore, nanofibers were evaluated regarding their physical properties, such as tensile behavior, water uptake capacity, and water contact angle. The results reveal that CS/SF/N-CQDs/α-TCP showed lower MIC values against E. coli and S. aureus (1.45 ± 0.26 mg/mL and 1.59 ± 0.12 mg/mL) compared to other synthesized materials. Also, in-vitro investigations were performed, and the MTT assay on the HFF cell line revealed that CS/SF/N-CQDs/α-TCP nanofiber could possess good biocompatibility. Interestingly, the scratch test proved that faster cell migration and proliferation occurred in the presence of CS/SF/N-CQDs/α-TCP (73 ± 3.12 %). Finally, we examined the wound healing ability of CS/SF/N-CQDs/α-TCP nanofiber using an animal model. The results confirmed that produced nanofiber could efficiently promote wound closure by 96.73 ± 1.25 % in 12 days. Histopathological analyses verified accelerated re-epithelization and well-structured epidermis in CS/SF/N-CQDs/α-TCP nanofiber-treated group. Based on our findings, the CS/SF/N-CQDs/α-TCP nanofiber with excellent antimicrobial properties is highly suitable for wound healing and skin tissue regeneration applications.

Assessment of synthesized chitosan/halloysite nanocarrier modified by carbon nanotube for pH-sensitive delivery of curcumin to cancerous media

Constructing a system to carry medicine for more effective remedy of cancer has been a leading challenge, as the number of cancer cases continues to increase. In this present research, a curcumin-loaded chitosan/halloysite/carbon nanotube nanomixture was fabricated by means of water/oil/water emulsification method. The drug loading efficiency (DL) and entrapment efficiency (EE), as a result, reached 42 % and 88 %, respectively and FTIR and XRD analysis confirmed the bonding between the drug and nanocarrier. Morphological observation through FE-SEM and characterization through DLS analysis demonstrated that the average size of nanoparticles is 267.37 nm. Assessment of release within 96 h in pH 7.4 and 5.4 showed sustained release. For more investigation, release data was analyzed by diverse kinetic models to understand the mechanism in the release procedure. An MTT assay was also carried out, and the results illustrated apoptosis induction on MCF-7 cells and exhibited ameliorated cytotoxicity of the drug-loaded nanocomposite compared to the free curcumin. These findings suggest that the unique pH-responsive chitosan/halloysite/carbon nanotube nanocomposite might make a good option for drug delivery systems, particularly for the cancer treatment.

Synthesis of a novel pH-responsive Fe3O4/chitosan/agarose double nanoemulsion as a promising Nanocarrier with sustained release of curcumin to treat MCF-7 cell line

Nanotechnology, using drug carriers, has gained remarkable achievements in treating cancer by inhibiting the adverse effects of traditional therapeutic methods, such as applying curcumin. Using chitosan could help to target tumors, without harming healthy cells. Also, magnetic iron oxide provides a high specific area to increase the capability of the nano-scale vehicle to load curcumin. A double emulsion hydrogel of Fe₃O₄/chitosan/agarose was synthesized and curcumin was loaded with loading and entrapment efficacies of 48.25 % and 87.5 %, respectively. The crystalline nature of the nanocomposites was confirmed by X-ray diffraction, and Fourier transforms spectroscopy investigated the functional groups of the components. The results of DLS and zeta potential showed proper particle size and surface charge, which are important for making the EPR effect and stability of the developed drug delivery system. The release profile of curcumin from the nanocarrier presented a sustained and pH-responsive release, avoiding overdosage and decreasing side effects. The best kinetic model that the release data could be fitted on was Hixon-Crowell. Finally, from the cytotoxicity of the prepared nanocomposite, it was concluded that the nanocarrier is biocompatible, and from flow cytometry analysis, a high apoptosis percentage proved that the effect of the designed drug delivery system on MCF-7 cell lines is programmed. Hence, this curcumin-loaded double emulsion could mitigate cancer therapy restrictions, with a minimum toxic effect on cultured cells.

Wound dressing based on PVA nanofiber containing silk fibroin modified with GO/ZnO nanoparticles for superficial wound healing: In vitro and in vivo evaluations

Silk fibroin (SF), extracted from Bombyx mori, has unique physicochemical properties to achieve an efficient wound dressing. In this study, reduced graphene oxide (RGO)/ZnO NPs/silk fibroin nanocomposite was made, and an innovative nanofiber of SF/polyvinyl alcohol (PVA)/RGO/ZnO NPs was ready with the electrospinning technique and successfully characterized. The results of MIC and OD analyses were used to investigate the synthesized materials' antibacterial effects and displayed that the synthesized materials could inhibit growth against Staphylococcus aureus and Escherichia coli bacteria. However, both in vitro cytotoxicity (MTT) and scratch wound studies have shown that RGO/ZnO NPs and SF/PVA/RGO/ZnO NPs are not only non-toxic to NIH 3T3 fibroblasts, but also can cause cell viability, cell proliferation, and cell migration. Furthermore, improving the synthesized nanofiber's structural properties in the presence of RGO and ZnO NPs has been confirmed by performing tensile strength, contact angle, and biodegradation analyses. Also, in a cell attachment analysis, fibroblast cells had migrated and expanded well in the nanofibrous structures. Moreover, in vivo assay, SF/PVA/RGO/ZnO NPs nanofiber treated rats and has been shown significant healing activity and tissue regeneration compared with other treated groups. Therefore, this study suggests that SF/PVA/RGO/ZnO NPs nanofiber is a hopeful wound dressing for preventing bacteria growth and improving superficial wound repair.

Synthesis and characterization of a novel, pH-responsive sustained release nanocarrier using polyethylene glycol, graphene oxide, and natural silk fibroin protein by a green nano emulsification method to enhance cancer treatment

In this study, for the first time, by employing a simple and efficient double nano-emulsification method and using sweet almond oil as the organic phase, polyethylene glycol (PEG)/graphene oxide (GO)/silk fibroin (SF) hydrogel-nanocomposite was synthesized. The aim of the research was to fabricate a biocompatible targeted pH-sensitive sustained release carrier, improve the drug loading capacity and enhance the anticancer effect of doxorubicin (DOX) drug. The obtained values for the entrapment (%EE) and loading efficacy (%LE) were 87.75 ± 0.7 % and 46 ± 1 %, respectively, and these high values were due to the use of GO with a large specific surface area and the electrostatic interaction between the drug and SF. The Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses confirmed the presence of all the components in the nanocomposite and the suitable interaction between them. Based on the results of dynamic light scattering analysis (DLS) and zeta potential analysis, the mean size of the carrier particles and its surface charge were 293.7 nm and -102.9 mV, respectively. The high negative charge was caused by the presence of hydroxyl groups in GO and SF and it caused proper stability of the nanocomposite. The spherical core-shell structure with its homogeneous surface was also observed in the field emission scanning electron microscopy (FE-SEM) image. The cumulative release percentage of the nanocarrier reached 95.75 after 96 h and it is higher in the acidic environment at all times. The results of fitting the release data to the kinetic models suggested that the mechanism of release was dissolution-controlled anomalous at pH 7.4 and diffusion-controlled anomalous at pH 5.4. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry showed an increase in toxicity on MCF-7 cells and improved apoptotic cell death compared to the free drug. Consequently, the findings of this research introduced and confirmed PEG/GO/SF nanocomposite as an attractive novel drug delivery system for pH-sensitive and sustained delivery of chemotherapeutic agents in biomedicine.

Development of chitosan/halloysite/graphitic‑carbon nitride nanovehicle for targeted delivery of quercetin to enhance its limitation in cancer therapy: An in vitro cytotoxicity against MCF-7 cells

Although quercetin (QC) has valuable advantages, its low water solubility and poor permeability have limited its utilization as an anticancer drug. In this study, hydrogel nanocomposite of chitosan (CS), halloysite (HNT), and graphitic‑carbon nitride (g-C3N4) was prepared and loaded by QC using a water in oil in water emulsification process to attain QC sustained-release. Using g-C3N4 in the HNT/CS hydrogel solution enhanced the entrapment effectiveness (EE %) by up to 86 %. The interactions between QC and nanoparticles caused the nanocomposite pH-responsive behavior that assists in minimizing the side effect of the anticancer agent by controlling the burst release of QC at neutral conditions. According to DLS analysis, the size of the QC-loaded nanovehicle was 454.65 nm, showing that nanoparticles are highly monodispersed, which also was approved by FE-SEM. Additionally, Zeta potential value for the fabricated drug-loaded nanocarrier is +55.23 mV displaying that nanoparticles have good stability. The hydrogel nanocomposite structure's completeness was shown by FTIR pattern, and quercetin was included into the designed delivery system based on XRD data. Besides, the drug release profile indicated that a targeted sustained-release and pH-sensitive release of anticancer drug with the 96-hour extended-release were noticed. In order to comprehend the process of QC release at pH 5.4 and 7.4, four kinetic models were employed to find the best-suited model according to the acquired release data. Finally, the MTT experiment revealed considerable cytotoxicity against breast cancer cells, MCF-7 cell line was experimented in vitro, for the CS/HNT/g-C3N4 targeted delivery system in comparison to QC as a free drug. According to the above description, the CS/HNT/g-C3N4 delivery platform is a unique pH-sensitive drug delivery system for anticancer purposes that improves loading as well as sustained-release of quercetin.

The function of chitosan/agarose biopolymer on Fe2 O3 nanoparticles and evaluation of their effects on MCF-7 breast cancer cell line and expression of BCL2 and BAX genes

In recent decades, magnetic nanoparticles modified with biocompatible polymers have been recognized as a suitable tool for treating breast cancer. The aim of this research was to evaluate the function of chitosan/agarose-functionalized Fe₂ O₃ nanoparticles on the MCF-7 breast cancer cell line and the expression of BCL2 and BAX genes. Free Fe₂ O₃ nanoparticles were prepared by hydrothermal method. FTIR, XRD, SEM, DLS, VSM, and zeta potential analyses determined the size and morphological characteristics of the synthesized nanoparticles. The effect of Fe₂ O₃ free nanoparticles and formulated Fe₂ O₃ nanoparticles on induction of apoptosis was studied by double-dye Annexin V-FITC and PI. Also, the gene expression results using the PCR method displayed that Fe₂ O₃ formulated nanoparticles induced BAX apoptosis by increasing the anti-apoptotic gene expression and decreasing the expression of pro-apoptotic gene BCL2, so the cell progresses to planned cell death. In addition, the results showed that the BAX/BCL2 ratio decreased significantly after treatment of MCF-7 cells with free Fe₂ O₃ nanoparticles, and the BAX/BCL2 ratio for Fe₂ O₃ formulated nanoparticles increased significantly. Also, to evaluate cell migration, the scratch test was performed, which showed a decrease in motility of MCF-7 cancer cells treated with Fe₂ O₃ nanoparticles formulated with chitosan/agarose at concentrations of 10, 50, 100, and 200 μg/ml.

PVA-Based Nanofibers Containing Chitosan Modified with Graphene Oxide and Carbon Quantum Dot-Doped TiO2 Enhance Wound Healing in a Rat Model

Electrospun nanofibrous constructs based on nanoparticles and biopolymers have recently been used in tissue engineering because of their similarity to the extracellular matrix in nature. In this study, electrospun chitosan-carbon quantum dot-titanium dioxide-graphene oxide (CS-CQD-TiO₂-GO) nanofibrous mats were synthesized for use as wound dressings by the electrospinning method. To increase the biodegradation rate and water resistance, the fabricated nanofibrous mats were cross-linked. SEM images showed a uniform and coherent structure of CS-CQD-TiO₂-GO nanocomposites and CS-CQD-TiO₂-GO electrospun nanofibers mats. FTIR analysis, XRD pattern, SEM mapping, and EDS spectrum demonstrate the accuracy of the synthesis as well as the elemental and chemical structure of the nanofibrous mat. The water contact angle indicated that the nanofibrous mat had a hydrophilic property, which is essential for controlling wound exudates. The tensile strength and elongation tests showed that the nanofibrous mat has suitable mechanical properties for wound dressing, including significant flexibility and strength. Interestingly, antimicrobial testing illustrated that the fabricated nanofibrous mat had antibacterial activity against Gram-negative and Gram-positive bacteria. Appropriate cell viability and cytocompatibility of treated mouse fibroblast NIH3T3 cells with the nanofibrous mat were determined using an MTT assay. The animal study results confirmed the proper potential of the nanofibrous mat in wound dressing applications.

Bacillales: From Taxonomy to Biotechnological and Industrial Perspectives

For a long time, the genus Bacillus has been known and considered among the most applicable genera in several fields. Recent taxonomical developments resulted in the identification of more species in Bacillus-related genera, particularly in the order Bacillales (earlier heterotypic synonym: Caryophanales), with potential application for biotechnological and industrial purposes such as biofuels, bioactive agents, biopolymers, and enzymes. Therefore, a thorough understanding of the taxonomy, growth requirements and physiology, genomics, and metabolic pathways in the highly diverse bacterial order, Bacillales, will facilitate a more robust designing and sustainable production of strain lines relevant to a circular economy. This paper is focused principally on less-known genera and their potential in the order Bacillales for promising applications in the industry and addresses the taxonomical complexities of this order. Moreover, it emphasizes the biotechnological usage of some engineered strains of the order Bacillales. The elucidation of novel taxa, their metabolic pathways, and growth conditions would make it possible to drive industrial processes toward an upgraded functionality based on the microbial nature.

A TGF-α and TGF-β1 Poloxamer-based micelle/hydrogel composite: A promising novel candidate for the treatment of anosmia

Anosmia is the inability to smell or loss of the sense of smell. It can reduce your ability to detect the smell of smoke, gas leaks, or spoiled food, as well as hinder the quality of life related to social interactions and feelings of well-being. In the current study, a drug delivery composite was designed to cure anosmia and its efficiency in delivering transforming growth factor alpha (TGF-α) and transforming growth factor beta 1 (TGF-β1) to the nasal cavity was evaluated. Bovine serum albumin (BSA) was used as a model protein for encapsulation into Poloxamers 407 micelles. For the optimization of the BSA-micelle formulation, a two-parameter five-level central composite design (CCD) was applied. The BSA-micelle was optimized with a particle size of 41 nm, drug loading of 8%, and encapsulation efficiency of 74%. Further, the BSA-micelle was characterized by FESEM, TEM, and FTIR. The analysis of release profile suggested high-paced free BSA release compared to the gradual and prolonged release of BSA-micelle/hydrogel and BSA-micelles. The cytotoxicity assay demonstrated the safety of TGF-α and TGF-β1-micelles/hydrogel. Moreover, it was observed that TGF-α and TGF-β1 within the hydrogels promote cellular viability and human olfactory ectomesenchymal stem cell OE-MSCs proliferation. In conclusion, According to the results of our study, the TGF-α and TGF-β1-micelle/hydrogel-based delivery system provides a suitable alternative for anosmia treatment.

Construction of Aptamer-Based Nanobiosensor for Breast Cancer Biomarkers Detection Utilizing g-C3N4/Magnetic Nano-Structure

An electrochemical aptasensor has been developed to determine breast cancer biomarkers (CA 15-3). Aptamer chains were immobilized on the surface of the electrode by g-C₃N₄/Fe₃O₄ nanoparticles, which increased the conductivity and active surface area of the electrode. X-ray diffraction analysis (XRD), Fourier-transformed infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) measurements have been carried out to characterize the nanomaterials. Cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy have been used to characterize the developed electrode. The results demonstrate that the modified electrode has better selectivity for CA 15-3 compared to other biological molecules. It has a good electrochemical response to CA 15-3 with a detection limit of 0.2 UmL^-1 and a linear response between 1 and 9 UmL^-1. It has been used as a label-free sensor in potassium ferrocyanide medium and as methylene blue-labeled in phosphate buffer medium. This electrode was successfully applied to analyze the serum of diseased and healthy individuals, which corroborates its high potential for biosensing applications, especially for the diagnosis of breast cancer.

PVA based nanofiber containing GO modified with Cu nanoparticles and loaded curcumin; high antibacterial activity with acceleration wound healing

BACKGROUND

The skin is one of the most essential organs of the body that plays a vital role. Protecting the skin from damage is one of the most critical challenges. Therefore, the ideal wound dressing that has antibacterial, mechanical, biodegradable, and non-toxic properties can protect the skin against injury and accelerate and heal the wound.

OBJECTIVE

in this study, a nano-wound dressing is designed for the first time. This work is aimed to optimize and act as a dressing to speed up the wound healing process.

METHODS

Graphene Oxide (GO) was produced by the hummer method. In the next step, GO-copper (Cu) nanohybrid was prepared, then GO-Cu -Curcumin (Cur) nanohybrid was synthesized. Using the electrospinning method, polyvinyl alcohol (PVA)/ GO-Cu -Cur were spun, and finally, related analyzes were performed to investigate the properties and synthesized chemicals.

RESULTS

The results showed that the nanocomposite was synthesized correctly and the diameter of the nanofibers was 328 nm. The use of PVA improved the mechanical properties. In addition, the wound dressing had biodegradable, antimicrobial, and non-toxic properties. The results of the scratch test and animal model showed that this nanocomposite accelerated wound healing and after 14 days showed 92.25% wound healing.

CONCLUSION

The synthesized nanocomposite has the individual properties and characteristics of an ideal wound dressing and replaces traditional methods for wound healing.

Preparation of a pH‐responsive chitosan‐montmorillonite‐nitrogen‐doped carbon quantum dots nanocarrier for attenuating doxorubicin limitations in cancer therapy

Despite its widespread usage as a chemotherapy drug in cancer treatment, doxorubicin (DOX) has limitations such as short in vivo circulation time, low solubility, and poor permeability. In this regard, a pH‐responsive chitosan (CS)‐ montmorillonite (MMT)‐ nitrogen‐doped carbon quantum dots (NCQDs) nanocomposite was first developed, loaded with DOX, and then incorporated into a double emulsion to further develop the sustained release. The incorporated NCQDs into the CS‐MMT hydrogel exhibited enhanced loading and entrapment efficiencies. The presence of NCQDs nanoparticles in the CS‐MMT hydrogel also resulted in an extended pH‐responsive release of DOX over a period of 96 h compared to that of CS‐MMT‐DOX nanocarriers at pH 5.4. Based on the Korsmeyer‐Peppas model, there was a controlled DOX release at pH 5.4, while no diffusion was observed at pH 7.4, indicating fewer side effects. MTT assay showed that the cytotoxicity of DOX‐loaded CS‐MMT‐NCQDs hydrogel nanocomposite was significantly higher than those of free DOX (p < 0.001) and CS‐MMT‐NCQDs (p < 0.001) on MCF‐7 cells. Flow cytometry results demonstrated that a higher apoptosis induction achieved after incorporating NCQDs nanoparticles into CS‐MMT‐DOX nanocarrier. These findings suggest that the DOX‐loaded nanocomposite is a promising candidate for the targeted treatment of cancer cells.

Evaluation of SDS‐coated iron nanostructure on the gene expression of bio surfactant‐producing genes by Pseudomonas aeruginosa

Bio surfactants are natural surfactants that induce emulsification, displacement, increased solubility, and mobility of hydrophobic organic compounds. In this study, the gene expression of biosurfactant production genes by Pseudomonas aeruginosa in the presence of sodium dodecyl sulfate coated iron nanostructure (Fe/SDS) were evaluated. Emulsification Index and Surface Tension reduction test to check stability and emulsification the rhamnolipid were done. Purification was evaluated using thin layer chromatography (TLC) and expression of rhlA, mvfR, lasR, rhlR genes was determined using q‐PCR technique. Binding of nanoparticles to bio surfactants was confirmed by TEM. The best emulsification index, was by the sample that exposed to 1 mg/L Fe/SDS nanoparticles for 2 days. Rhamnolipid produced in the presence of nanoparticles had an acceptable ability to reduce surface tension. The Rf (retention factor) value obtained was 0.63 by chromatography. q‐PCR results showed that the expression of rhlA, mvfR, lasR, rhlR genes was significantly increased in Fe/SDS treated cells, which indicates the significant positive effect (P < 0.05) of nanoparticles on biosurfactant production of treated cells. While, SDS and Fe alone were not affected significantly (P > 0.05) on the expression of these genes. Our findings indicated the importance of nanoparticles in increasing the expression of genes involved in the bio surfactant production pathway of Pseudomonas aeruginosa.

Chitosan/Gamma-Alumina/Fe3O4@5-FU Nanostructures as Promising Nanocarriers: Physiochemical Characterization and Toxicity Activity

Today, cancer treatment is an important issue in the medical world due to the challenges and side effects of ongoing treatment procedures. Current methods can be replaced with targeted nano-drug delivery systems to overcome such side effects. In the present work, an intelligent nano-system consisting of Chitosan (Ch)/Gamma alumina (γAl)/Fe3O4 and 5-Fluorouracil (5-FU) was synthesized and designed for the first time in order to influence the Michigan Cancer Foundation-7 (MCF-7) cell line in the treatment of breast cancer. Physico-chemical characterization of the nanocarriers was carried out using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), dynamic light scattering (DLS), and scanning electron microscopy (SEM). SEM analysis revealed smooth and homogeneous spherical nanoparticles. The high stability of the nanoparticles and their narrow size distribution was confirmed by DLS. The results of the loading study demonstrated that these nano-systems cause controlled, stable, and pH-sensitive release in cancerous environments with an inactive targeting mechanism. Finally, the results of MTT and flow cytometry tests indicated that this nano-system increased the rate of apoptosis induction on cancerous masses and could be an effective alternative to current treatments.

Inhibition performances of graphene oxide/silver nanostructure for the microbial corrosion: molecular dynamic simulation study

Steel is one of the mainly used materials in the oil and gas industry. However, it is susceptible to the marine corrosion, which 20% of the total marine corrosion is caused by microbiologically influenced corrosion (MIC). The economic and environmental impacts of corrosion are significant, and it is crucial to fight against corrosion in a proper sustainability context and environmental-friendly methods. In this study, the graphene oxide/silver nanostructure (GO-Ag) inhibitory effect on the corrosion of steel in the presence of sulfate reducing bacteria (SRB) was investigated, via weight loss (WL) and Tafel polarization measurements. Moreover, molecular dynamic (MD) simulations were performed to obtain a deep understanding of the corrosion inhibition effect of GO-Ag. GO-Ag showed a significant antibacterial effect at 80 ppm. Moreover, WL and Tafel polarization measurements illustrated a great inhibition efficiency, which reached up to 84% reduction of WL and 98% reduction of corrosion current density (I_corr) after 7 days of incubation with GO-Ag. Based on MD simulations, bonding energy reached to the larger value in the presence of GO-Ag, which indicated the ability of graphene oxide nanosheets to be adsorbed on the steel surface and prevent the access of corrosive agents to the steel surface. The radial distribution function (RDF) results implied distance between corrosive agent (water and SRB) and steel surface (Fe atoms), which indicated protection of the steel surface due to the effective adsorption of GO nanosheets through the active sites of the steel surface. The mean square displacement (MSD) result showed smaller displacement of the corrosive particles on the surface of steel, resulting that the GO-Ag molecules bonded with Fe molecules on the surface of steel.

Investigating the effect of nanoparticle on phenanthrene biodegradation by Labedella gwakjiensis strain KDI

Polycyclic aromatic hydrocarbons (PAHs), as persistent organic contaminants, are a major source of concern due to their toxic effect on ecosystems and human health. This study attempted to isolate halotolerant PAHs degrading bacteria from saline oil-contaminated soils. Among the isolates, strain KDI with the highest 16S rRNA gene sequence similarity to Labedella gwakjiensis was able to reduce surface tension (ST) from 65.42 to 26.60 mN m^-1 and increase the emulsification index to 81.04%, as a result of significant biosurfactant production. Response Surface Methodology (RSM) analysis was applied to optimize the factors, i.e. PAHs concentration and NaCl concentration as well as to determine the effect of these important variables on PAHs biodegradation. The Carbon Quantum Dots. Iron Oxide (CQDs.Fe₃O₄) nanoparticles were characterized by several popular analytical techniques, after which the effect of CQD.Fe₃O₄ nanoparticles on biodegradation was examined. PAHs biodegradation rate and efficiency of strain KDI to degrade PHE in the presence of CQD.Fe₃O₄ nanoparticles was analyzed by GC. According to the results during biodegradation both the concentration of PAHs and the amount of NaCl were effective. The biodegradation rate significantly increased in the presence of CQD.Fe₃O₄. The highest biodegradation of PHE occurred in the presence of 0.5 g/L of CQD.Fe₃O₄ which was 63.63% and 81.77% after 48 and 72 h of incubation. To the best of our knowledge, this is the first report on optimization of PAHs concentration and salinity by RSM and nanobioremediation of PHE using a bacterial strain in the presence of CQD.Fe₃O₄ nanoparticles.

Immobilization of Urease Enzyme on Chitosan/Polyvinyl alcohol Electrospun Nanofibers

Electrospun nanofibers have gained much attention for enzyme immobilization due to their high surface-to-volume ratio. In this study, urease was immobilized on chitosan/poly (vinyl alcohol) (PVA) nanofibers by both adsorption and crosslinking methods. In order to obtain nanofibers with more desirable properties, solutions with different ratios of chitosan and PVA were electrospun and crosslinked using glutaraldehyde. Comparing SEM images of the nanofibers, before and after immersing them in phosphate buffer, it was shown that higher chitosan content leads to more stable fibers. So, the solution with the chitosan to PVA ratio of 40:60 was used for enzyme immobilization. Then, the effects of initial protein concentration, temperature, incubation time, and method of immobilization were investigated to reach the highest enzyme activity. Under similar immobilization conditions, covalently immobilized urease showed higher activity, compared to uncrosslinked immobilized enzyme. Besides, it retained 30% of its initial activity after 10 times usage. So, this method was chosen for further investigation. Not only the activity of the immobilized enzyme was much higher than the free enzyme in a wide range of pH and temperature, but also stability of the immobilized enzyme was improved. Immobilized urease was then used to remove thiourea which is a toxic compound. Findings indicated 60% hydrolysis of initial thiourea in 12 hours. In conclusion, the findings showed that chitosan/PVA nanofibers are suitable candidates for the immobilization of urease. This article is protected by copyright. All rights reserved.

A novel pH-responsive nanoniosomal emulsion for sustained release of curcumin from a chitosan-based nanocarrier: emphasis on the concurrent improvement of loading, sustained release, and apoptosis induction

Curcumin application as an anti-cancer drug is faced with several impediments. This study has developed a platform that facilitates the sustained release of curcumin, improves loading efficiency, and anti-cancer activity. Montmorillonite (MMT) nanoparticles were added to chitosan (CS)-agarose (Aga) hydrogel and then loaded with curcumin (Cur) to prepare a curcumin-loaded nanocomposite hydrogel. The loading capacity increased from 63% to 76% by adding MMT nanoparticles to a chitosan-agarose hydrogel. Loading the fabricated nanocomposite in the nanoniosomal emulsion resulted in sustained release of curcumin under acidic conditions. Release kinetics analysis showed diffusion and erosion are the dominant release mechanisms, indicating non-fickian (or anomalous) transport based on the Korsmeyer-Peppas model. FTIR spectra confirmed that all nanocomposite components were present in the fabricated nanocomposite. Besides, XRD results corroborated the amorphous structure of the prepared nanocomposite. Zeta potential results corroborated the stability of the fabricated nanocarrier. Cytotoxicity of the prepared CS-Aga-MMT-Cur on MCF-7 cells was comparable to that of curcumin-treated cells (p <0.001). Moreover, the percentage of apoptotic cells increased due to the enhanced release profile resulting from the addition of MMT to the hydrogel and the incorporation of the fabricated nanocomposite into the nanoniosomal emulsion. To recapitulate, the current delivery platform improved loading, sustained release, and curcumin anti-cancer effect. Hence, this platform could be a potential candidate to mitigate cancer therapy restrictions with curcumin. This article is protected by copyright. All rights reserved.

Fabrication of Au/Fe 3 O 4 /RGO based aptasensor for measurement of miRNA‐128, a biomarker for acute lymphoblastic leukemia (ALL)

Due to their high sensitivity, simplicity, portability, self‐contained, and low cost, the development of electrochemical biosensors is a beneficial way to diagnose and anticipate many types of cancers. An electrochemical nanocomposite‐based aptasensor is fabricated for the determination of miRNA‐128 concentration as the acute lymphoblastic leukemia (ALL) biomarker for the first time. The aptamer chains were immobilized on the surface of the glassy carbon electrode (GCE) through gold nanoparticles/magnetite/reduced graphene oxide (AuNPs/Fe₃O₄/RGO). Fast Fourier transform infrared (FTIR), X‐ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM) were used to characterize synthesized nanomaterials. Cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) were used to characterize the modified GCE in both label‐free and labeled methods. The results indicate that the modified working electrode has high selectivity and for miRNA‐128 over other biomolecules. The hexacyanoferrate redox system typically operated at around 0.3 V (vs. Ag/AgCl), and the methylene blue redox system ran at about 0 V, were used as an electrochemical probe. The detection limit and linear detection range for hexacyanoferrate and methylene blue are 0.05346 fM, 0.1–0.9 fM, and 0.005483 fM, 0.01–0.09 fM, respectively. The stability and diffusion control analyses were performed as well. In both label‐free and labeled methods, the modified electron showed high selectivity for miRNA‐128. The use of methylene blue as a safer redox mediator caused miRNA‐128 to be detected with greater accuracy at low potentials in PBS media. The findings also show the substantial improvement in detection limit and linearity by using reduced graphene oxide‐magnetite‐gold nanoparticles that can be verified by comparing with previous studies on the detection of other miRNAs.

Ultra pH-sensitive nanocarrier based on Fe2O3/chitosan/montmorillonite for quercetin delivery

Harmful side effects of the chemotherapeutic agent have been investigated in many recent studies. Since Fe₂O₃ nanoparticles have proper porosity, they are capable for loading noticeable amount of drugs and controlled release. We developed Fe₂O₃/chitosan/montmorillonite nanocomposite. Quercetin (QC) nanoparticles, which have fewer side effects than chemical anti-tumor drugs, were encapsulated in the synthesized nanocarrier and were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), dynamic light scattering (DLS), and zeta potential. For quercetin, the encapsulation efficiency and the loading efficiency of the drug in Fe₂O₃-CS-MMT@QC were found to be about 94% and 57%, respectively. The release profile of QC in different mediums indicated pH-dependency and controlled release of the nanocomposite, adhering to The Weibull kinetic model. Biocompatibility of the Fe₂O₃/CS/MMT nanoparticles against the MCF-7 cells was shown by MTT assay and confirmed by flow cytometry. These data demonstrate that the designed Fe₂O₃-CS-MMT@QC would have potential drug delivery to treat cancer cells.

Detection of Microorganisms Using Graphene-Based Nanobiosensors

Having an insight into graphene and graphene derivatives such as graphene oxide, reduced graphene oxide and graphene quantum dots is necessary since it can help scientists to detect possible properties and features that could be useful when using these carbon materials in preparation of a nanocomposites. In recent years, graphene and its derivatives have attracted a lot of attention and been extensively applied in biosensors due to fascinating properties, such as large surface area, optical and magnetic properties, and high elasticity for the detection of microorganisms as they can be modified with some other materials such as macromolecules, oxide metals and metals to improve the electrochemical behaviour of the biosensor. In this review paper, biosensor design strategies based on graphene and its derivatives (graphene-based nanocomposites in biosensors) are described. Then their application for the detection of microorganisms including prions, viroids, viral and bacterial cells as well as fungi, protozoa, microbial toxins and even microbial sources of antibiotics is reviewed.

Ultra pH-sensitive detection of total and free prostate-specific antigen using electrochemical aptasensor based on reduced graphene oxide/gold nanoparticles emphasis on TiO2/carbon quantum dots as a redox probe

The development of a rapid, sensitive, and straightforward detection method of prostate-specific antigen (PSA) is indispensable for the early diagnosis of prostate cancer (PCa). This work relates an electrochemical method using functionalized single-stranded DNA aptamer to diagnose PCa and benign prostate hyperplasia. The sensing platform relies on PSA recognition by aptamer/Au/GO-nanohybrid-modified glassy carbon electrode. Besides ferrocyanide TiO2/carbon quantum dots (CQDs) probe is used to investigate the effect of nanoparticle-containing electrolyte. Optimization of incubation time of aptamer/Au/GO-nanohybrid and volume fraction of nafion were done using Design Expert 10 software reporting 42.4 h and 0.095% V/V, respectively. In ferrocyanide medium, PSA detection as low as 3, 2.96, and 0.85 ng mL-1 was achieved with a dynamic range from 0.5 to 7 ng ml-1, in accord with clinical values, using cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy, respectively. Moreover, this sensor exhibited conspicuous performance in TiO2/CQDs-containing medium with different pH values of 5.4 and 8 to distinguish total PSA and free PSA, resulting in very low limit of detections, 0.028, and 0.007 ng ml-1, respectively. The results manifested the proposed system as a forthcoming sensor in a clinical and point of care analysis of PSA.

An electrochemical aptasensor for detection of prostate-specific antigen using reduced graphene gold nanocomposite and Cu/carbon quantum dots

We report a label-free electrochemical aptamer-based biosensor for the detection of human prostate-specific antigen (PSA). The thiolate DNA aptamer against PSA was conjugated to the reduced graphene oxide/Au (RGO-Au) nanocomposite through the self-assembly of Au-S groups. Owing to the large volume to surface ratio, the RGO-Au nanocomposite provides a large surface for aptamer loading. The RGO-Au/aptamer was combined with a Nafion polymer and immobilized on a glassy carbon electrode. The interaction of aptamer with PSA was studied by cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The detection of limit for prepared electrode was obtained about 50 pg/mL at the potential of 0.4 V in potassium hexacyanoferrate [K₄ Fe(CN)₆ ] medium. To decrease the limit of detection (LOD) and applied potential of the prepared nanoprobe Cu/carbon quantum dots (CuCQD) is introduced as a new redox. The results show that this new electrochemical medium provides better conditions for the detection of PSA. LOD of a nanoprobe in CuCQD media was obtained as 40 pg/mL at the potential of -0.2 V. Under optimal conditions, the aptasensor exhibits a linear response to PSA with a LOD as small as 3 pg/mL. The present aptasensor is highly selective and sensitive and shows satisfactory stability and repeatability.

A novel biosurfactant producing Kocuria rosea ABR6 as potential strain in oil sludge recovery and lubrication

Biosurfactants are amphiphilic molecules composed of a hydrophilic and hydrophobic moiety and had the ability to penetrate into different phases to reduce the surface tension. This features caused to oil recovery, lubrication and facilities of crude oil in pipeline. In current research Biosurfactant-producing strain was isolated from the storage tanks of the Isfahan Oil Refining Company in Iran, and screened by oil expansion test, droplet collapse, and surface tension reduction measurement. Hydrocarbon recovery from crude oil sludge was measured under constant conditions. The effect of factoring biosource lubrication on crude oil in pipelines was investigated in vitro. Also, the optimization of biosurfactant production in different conditions was measured as a single factor and using Response Surface Method (RSM). The best biosurfactant-producing bacterium was identified as Kocuria rosea ABR6, and its sequence was registered in the gene bank with access number of MK100469. Chemical analysis proved that the produced biosurfactant was a lipopeptide. 7% of crude oil was recovered from petroleum sludge by biosurfactant obtained from Kocuria rosea ABR6. Also, the speed of crude oil transfer in pipelines was upgraded as it could be said that for a certain distance the transfer time reduced from 64 to 35 s. The highest biosurfactant production was measured at pH 9, aeration rate of 120 rpm and 96 h after incubation. The use of biosurfactants produced by Kocuria rosea ABR6 is recommended to remove oil sludge and lubricate oil in pipelines recommended in the oil industry.

PVA based nanofiber containing cellulose modified with graphitic carbon nitride/nettles/trachyspermum accelerates wound healing

Today, bacterial cellulose has received a great deal of attention for its medical applications due to its unique structural properties such as high porosity, good fluid uptake, good strength, and biocompatibility. This study aimed to fabricate and study bacterial cellulose/graphitic carbon nitride/nettles/trachyspermum nanocomposite by immersion and PVA/BC/g-C₃ N₄ /nettles/trachyspermum nanofiber by electrospinning method as a wound dressing. The g-C₃ N₄ and g-C₃ N₄ solution were synthesized and then were characterized using Fourier transform infrared, X-ray diffraction, Zeta Potential, and scanning electronic microscope analyzes. Also, the antibacterial properties of the synthesized materials were proved by gram-positive and gram-negative bacteria using the minimum inhibitory concentration method. Besides, the toxicity, migration, and cell proliferation results of the synthesized materials on NIH 3T3 fibroblasts were evaluated using MTT and scratch assays and showed that the BC/PVA/g-C₃ N₄ /nettles/trachyspermum composite not only had no toxic effect on cells but also contributed to cell survival, cell migration, and proliferation has done. To evaluate the mechanical properties, a tensile strength test was performed on PVA/BC/g-C₃ N₄ /nettles/trachyspermum nanofibers, and the results showed good strength of the nanocomposite. In addition, in vivo assay, the produced nanofibers were used to evaluate wound healing, and the results showed that these nanofibers were able to accelerate the wound healing process so that after 14 days, the wound healing percentage showed 95%. Therefore, this study shows that PVA/BC/g-C₃ N₄ /nettles/trachyspermum nanofibers effectively inhibit bacterial growth and accelerate wound healing.