This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue eng... more Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue engineering that can be resolved by oxygen‐generating biomaterials (OGBs). Two main issues related to OGBs are controlling oxygenation and reactive oxygen species (ROS). To address these concerns, we developed a composite scaffold entailing three layers (hydrogel‐electrospun fibers‐hydrogel) with antioxidant and antibacterial properties. The fibers, the middle layer, reinforced the composite structure, enhancing the mechanical strength from 4.27 ± 0.15 to 8.27 ± 0.25 kPa; also, this layer is made of calcium peroxide and silk fibroin (SF) through electrospinning, which enables oxygen delivery. The first and third layers are physical SF hydrogels to control oxygen release, containing quercetin (Q), a nonenzymatic antioxidant. This composite scaffold resulted in almost more than 40 mmHg of oxygen release for at least 13 days, and compared with similar studies is in a high range. Here, Q was used for the first time for an OGB to scavenge the possible ROS. Q delivery not only led to antioxidant activity but also stabilized oxygen release and enhanced cell viability. Based on the given results, this composite scaffold can be introduced as a safe and controllable oxygen supplier, which is promising for tissue engineering applications, particularly for bone.
Cell survival of thick engineered scaffolds is often compromised due to limited oxygen diffusion.... more Cell survival of thick engineered scaffolds is often compromised due to limited oxygen diffusion. Therefore, the design of oxygen-delivering nanofibrous polyurethane (PU)-calcium peroxide (CPO) scaffolds was investigated in this study. The average size of CPO nanoparticles was [Formula: see text][Formula: see text]nm. The average diameter of PU fibers was [Formula: see text]m, which was increased to [Formula: see text], [Formula: see text], and [Formula: see text]m upon incorporation of 0.1[Formula: see text]wt.%, 0.5[Formula: see text]wt.% and 1[Formula: see text]wt.% CPO, respectively. The CPO-containing scaffolds could produce oxygen for at least 13 days. Samples containing 0.5% CPO showed the highest oxygen release without a significant change in pH. For this sample, the addition of ascorbic acid as an antioxidant to counteract the possible formation of ROS, reduced the fiber diameter to [Formula: see text]m and increased the oxygen release. Adding 0.5% CPO improved the cell viability on the fifth day. In addition, the PU-CPO composite scaffold showed strong antibacterial activity. Overall, designed scaffolds could be useful in different tissue engineering applications to overcome the limited oxygen availability early after implantation.
The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out... more The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore, in vitro degradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal stem cell viability. It is worth mentioning that this is the first report investigating the conductivity of PLLA/PAMAM nanofiber. The results revealed that by increasing the amount of PAMAM, the ionic conductivity of scaffolds was enhanced by about nine times. Moreover, the outcomes indicated that the presence of PAMAM could improve the limitations of PLLA like hydrophobicity, lack of active group, and poor cell adhesion.
Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue eng... more Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue engineering that can be resolved by oxygen‐generating biomaterials (OGBs). Two main issues related to OGBs are controlling oxygenation and reactive oxygen species (ROS). To address these concerns, we developed a composite scaffold entailing three layers (hydrogel‐electrospun fibers‐hydrogel) with antioxidant and antibacterial properties. The fibers, the middle layer, reinforced the composite structure, enhancing the mechanical strength from 4.27 ± 0.15 to 8.27 ± 0.25 kPa; also, this layer is made of calcium peroxide and silk fibroin (SF) through electrospinning, which enables oxygen delivery. The first and third layers are physical SF hydrogels to control oxygen release, containing quercetin (Q), a nonenzymatic antioxidant. This composite scaffold resulted in almost more than 40 mmHg of oxygen release for at least 13 days, and compared with similar studies is in a high range. Here, Q was us...
Hybrid electrospun scaffolds based on poly (L-lactic acid) (PLLA)/poly (amidoamine) (PAMAM-G2) de... more Hybrid electrospun scaffolds based on poly (L-lactic acid) (PLLA)/poly (amidoamine) (PAMAM-G2) dendrimer/gemini surfactant were fabricated for the enhancement of synergistic antibacterial activities. The second generation of poly (amidoamine) (PAMAM-G2) and cationic gemini surfactant were utilized to functionalize the optimum electrospun scaffolds. The gelatination process was utilized to improve the wettability of PLLA scaffolds to extend cell attachment and cell proliferation. PLLA nanofibrous scaffolds were characterized by energy dispersion x-ray, scanning electron microscopy images, mechanical properties, water contact angle, Fourier transform infrared spectroscopy, zeta potential and antibacterial assessment. In vitro cell biocompatibility was evaluated by 3-(4, 5- dimethylthiazoyl-2-yl)-2, 5-diphenyltetrazolium bromide assay and morphology of PC-12 cells cultured on hybrid nanofibrous scaffolds and gelatinized ones. The results indicated that the optimum scaffolds could succe...
Supplemental Material, sj-pdf-1-jit-10.1177_15280837211048155 for Needleless electrospun mats bas... more Supplemental Material, sj-pdf-1-jit-10.1177_15280837211048155 for Needleless electrospun mats based on polyamidoamine dendritic polymers for encapsulation of essential oils in personal respiratory equipment by Maryam Mounesan, Somaye Akbari and Bogumil E Brycki in Journal of Industrial Textiles
The amine-terminated dendritic polymer as a novel class macromolecules attracts lots of attention... more The amine-terminated dendritic polymer as a novel class macromolecules attracts lots of attention due to various characteristics such as hyperbranched structures, multi-functional end groups, and interior cavities. In this chapter, amine-terminated dendritic polymers were applied on two famous natural fabrics, cotton and linen fabrics, to investigate the physical and chemical characteristic through measuring wrinkle recovery angel, tensile strength, air permeability, bending length, moisture regain, and dye adsorption based on statistical analysis. Dye adsorption and moisture regain of both modified fabrics increased which can be related to providing host–guest properties of dendritic polymers. Improvements of physical properties of fabrics were confirmed by enhancement of tensile strength and wrinkle recovery along with decreases of bending length. Furthermore, the antibacterial properties revealed on the modified fabrics due to the presence of abundant amine-terminated groups. The...
The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out... more The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore, in vitro degradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal s...
The development of efficient strategies for the removal of heavy metal ions from aqueous solution... more The development of efficient strategies for the removal of heavy metal ions from aqueous solutions is rapidly demanded as these contaminants are very toxic and carcinogenic and show detrimental effects on the living creatures. The main focus of the current study is on the preparation and assessment of electrospun adsorptive nanofiber membranes for the removal of toxic Ni(II) and Cu(II) from wastewater in the ultrafiltration process. Hydrothermally synthesized titanate nanotubes (TNT) was modified with thiol functional groups and then directly incorporated to the polyvinyl chloride nanofiber matrices via electrospinning process to fabricate an adsorptive membrane. The as-prepared electrospun nanofiber membranes and the nanoadsorbents were characterized with respect to the physiochemical properties, surface structure and morphology, applying XPS, FTIR, FESEM, EDX and TEM analysis and then, the membranes were evaluated in terms of the removal of the heavy metal ions in a continuous ultrafiltration mode. In adsorptive filtration of the metal ions, the effective factors including nanoadsorbents loading (0.5-1.5 wt%), initial metal ion concentration (60-150 mg/L), feed temperature (~25 °C-45 °C), presence of competing ion and reusability were investigated in the UF system where the membranes containing 1.5 wt% thiol-modified TNT and virgin TNT adsorbents demonstrated excellent removal efficiency compared to the other membranes. The Cu(II) and Ni(II) removal efficiency of the membrane containing 1.5 wt% functionalized TNT was 90% and 86.7%, respectively which was the highest ones. As was expected and due to the uniform dispersion and less aggregation of the modified TNT adsorbents on the large surface area of the electrospun nanofibers, more adsorption capacity of the nanoparticles can be exploited. Moreover, the strong affinity of the thiol functional groups toward the metal cations, these membranes removed metal contaminants more efficiently. Besides, the Cu(II) removal efficiency of the fabricated membranes didn't show any drastic changes in the presence of the competing ions. Furthermore, acceptable performance was achieved for the prepared membranes even after four adsorption/regeneration cycles in the continuous UF experiments, demonstrating the feasibility and effectiveness of the prepared adsorptive nanofiber membranes for the removal of heavy metal ions.
Highlights Controlling the aminolysis reaction onto the PLLA scaffolds is important issue Ami... more Highlights Controlling the aminolysis reaction onto the PLLA scaffolds is important issue Aminolyzed PLLA scaffolds using PPI dendrimer enhanced surface characteristic. Aminolyzed PLLA scaffolds prevents the necrosis of cells by reducing acidic pH value
Magnesium (Mg)-based alloys are biodegradable metallic biomaterials that show promise in minimizi... more Magnesium (Mg)-based alloys are biodegradable metallic biomaterials that show promise in minimizing the risks of permanent metallic implants. However, their clinical applications are restricted due to their rapid in vivo degradation and low surface hemocompatibilities. Surface modifications are critically important for controlling the corrosion rates of Mg-based alloys and improving their hemocompatibilities. In the present study, two heparinization methods were developed to simultaneously increase the corrosion resistance and hemocompatibility of the AZ31 Mg alloy. In the first method, the surface of the AZ31 alloy was modified by alkali–heat treatment and then aminolyzed by 3-amino propyltriethoxy silane (APTES), a self-assembly molecule, and heparin was grafted onto the aminolyzed surface. In the second method, before heparinization, polyamidoamine dendrimers (PAMAM4-4) were grafted onto the aminolyzed surface with APTES to increase the number of surface functional groups, and he...
International Journal of Environmental Science and Technology, 2021
In this study, two different methods were used to introduce functionalized graphene oxide (GO) on... more In this study, two different methods were used to introduce functionalized graphene oxide (GO) onto the surface of nanofiltration (NF) membrane to improve its performance for heavy metal removal. The first method was based on coating in which the surface of NF membrane was coated with cross-linked GO, while the second method was introducing GO into monomer solution during interfacial polymerization. The efficiency of different methods was then compared by characterizing membrane physiochemical properties, as well as separation performance. With regard to performances, the water flux of TFN-i2 membrane (with GOs incorporated into thin layer) was reported to be 95 L/m2 h compared to 75 L/m2 h found in the TFN-c2 membrane (with GOs coated on the surface) at 8 bar. Both modified membranes exhibited higher water flux than the control membrane without GO incorporation (40 L/m2 h). Although the water flux of TFN-c2 membrane was lower, it achieved higher cobalt removal (97%) than that of TFN-i2 membrane (73%) due to its higher negative surface charge that improved separation via the Donnan exclusion effect.
Gemini surfactants consist of two cationic monomers of a surfactant linked together with a spacer... more Gemini surfactants consist of two cationic monomers of a surfactant linked together with a spacer. The specific structure of a cationic gemini surfactant is the reason for both its high surface activity and its ability to decrease the surface tension of water. The high surface activity and unique structure of gemini surfactants result in outstanding properties, including antibacterial and antifungal activity, anticorrosion properties, unique aggregation behaviour, the ability to form various structures reversibly in response to environmental conditions, and interactions with biomacromolecules such as DNA and proteins. These properties can be tailored by selecting the optimal structure of a gemini surfactant in terms of the nature and length of its alkyl substituents, spacer, and head group. Additionally, regarding their properties, comparison with their monomeric counterparts demonstrates that gemini surfactants have higher performance efficacy at lower concentrations. Hence, less material is needed, and the toxicity is lower. However, there are some limitations regarding their biocompatibility that have led researchers to develop amino acid-based and sugar-based gemini surfactants. Owing to their remarkable properties, cationic gemini surfactants are promising candidates for bioapplications such as drug delivery systems, gene carriers, and biomaterial surface modification.
The ever-increasing concern of air pollution triggered by broad-spreading contagious disease, bio... more The ever-increasing concern of air pollution triggered by broad-spreading contagious disease, bioterrorism, and release of dust particles in the air is targeted to be addressed in this paper by developing a novel personal respiratory equipment (PRE). For this purpose, polyamidoamine dendritic polymers (PAMAMs) were utilized not only for encapsulating tea tree essential oil (TEO), an antimicrobial material, but also for battling against perilous bioaerosols. Furthermore, TEO is encapsulated inside both PAMAM and polyacrylonitrile (PAN) electrospun nanofibers. Results clarified that electrospun samples containing both TEO and PAMAM possess thinner nanofibers with 440 nm reduction in their average diameter, and pursuantly higher filtration efficiency against both NaCl and paraffin oil mist particles about 98% and well above 99%, respectively. Herein, the electrospinning method is employed first for high porosity, enhanced surface area to volume ratio, and interconnected pores of result...
Based on scientific reports, several pharmacological drugs have some defects which restrict their... more Based on scientific reports, several pharmacological drugs have some defects which restrict their application in biomedical and clinical application. Nanotechnology by introducing dendrimers as an interesting nanotech polymers circumvents these difficulties and facilitate their application in the biomedicine field. Dendrimers with outstanding three-dimensional structure and extraordinary properties such as monodispersity, highly branched, well-defined structure, interior cavity spaces, and numerous surface functional groups are the best candidate to be utilized as drug nanocarriers and ideal therapeutic agents delivery systems. In this book chapter, firstly, we discuss why and which features of dendrimers make them promising structures for conjugating and encapsulation of drugs, and then inherent toxicity as a barrier for their therapeutic efficiency is considered, and then surface functionalization as common ways to address this problem are described. In the following, an introduct...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue eng... more Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue engineering that can be resolved by oxygen‐generating biomaterials (OGBs). Two main issues related to OGBs are controlling oxygenation and reactive oxygen species (ROS). To address these concerns, we developed a composite scaffold entailing three layers (hydrogel‐electrospun fibers‐hydrogel) with antioxidant and antibacterial properties. The fibers, the middle layer, reinforced the composite structure, enhancing the mechanical strength from 4.27 ± 0.15 to 8.27 ± 0.25 kPa; also, this layer is made of calcium peroxide and silk fibroin (SF) through electrospinning, which enables oxygen delivery. The first and third layers are physical SF hydrogels to control oxygen release, containing quercetin (Q), a nonenzymatic antioxidant. This composite scaffold resulted in almost more than 40 mmHg of oxygen release for at least 13 days, and compared with similar studies is in a high range. Here, Q was used for the first time for an OGB to scavenge the possible ROS. Q delivery not only led to antioxidant activity but also stabilized oxygen release and enhanced cell viability. Based on the given results, this composite scaffold can be introduced as a safe and controllable oxygen supplier, which is promising for tissue engineering applications, particularly for bone.
Cell survival of thick engineered scaffolds is often compromised due to limited oxygen diffusion.... more Cell survival of thick engineered scaffolds is often compromised due to limited oxygen diffusion. Therefore, the design of oxygen-delivering nanofibrous polyurethane (PU)-calcium peroxide (CPO) scaffolds was investigated in this study. The average size of CPO nanoparticles was [Formula: see text][Formula: see text]nm. The average diameter of PU fibers was [Formula: see text]m, which was increased to [Formula: see text], [Formula: see text], and [Formula: see text]m upon incorporation of 0.1[Formula: see text]wt.%, 0.5[Formula: see text]wt.% and 1[Formula: see text]wt.% CPO, respectively. The CPO-containing scaffolds could produce oxygen for at least 13 days. Samples containing 0.5% CPO showed the highest oxygen release without a significant change in pH. For this sample, the addition of ascorbic acid as an antioxidant to counteract the possible formation of ROS, reduced the fiber diameter to [Formula: see text]m and increased the oxygen release. Adding 0.5% CPO improved the cell viability on the fifth day. In addition, the PU-CPO composite scaffold showed strong antibacterial activity. Overall, designed scaffolds could be useful in different tissue engineering applications to overcome the limited oxygen availability early after implantation.
The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out... more The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore, in vitro degradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal stem cell viability. It is worth mentioning that this is the first report investigating the conductivity of PLLA/PAMAM nanofiber. The results revealed that by increasing the amount of PAMAM, the ionic conductivity of scaffolds was enhanced by about nine times. Moreover, the outcomes indicated that the presence of PAMAM could improve the limitations of PLLA like hydrophobicity, lack of active group, and poor cell adhesion.
Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue eng... more Supplying sufficient oxygen within the scaffolds is one of the essential hindrances in tissue engineering that can be resolved by oxygen‐generating biomaterials (OGBs). Two main issues related to OGBs are controlling oxygenation and reactive oxygen species (ROS). To address these concerns, we developed a composite scaffold entailing three layers (hydrogel‐electrospun fibers‐hydrogel) with antioxidant and antibacterial properties. The fibers, the middle layer, reinforced the composite structure, enhancing the mechanical strength from 4.27 ± 0.15 to 8.27 ± 0.25 kPa; also, this layer is made of calcium peroxide and silk fibroin (SF) through electrospinning, which enables oxygen delivery. The first and third layers are physical SF hydrogels to control oxygen release, containing quercetin (Q), a nonenzymatic antioxidant. This composite scaffold resulted in almost more than 40 mmHg of oxygen release for at least 13 days, and compared with similar studies is in a high range. Here, Q was us...
Hybrid electrospun scaffolds based on poly (L-lactic acid) (PLLA)/poly (amidoamine) (PAMAM-G2) de... more Hybrid electrospun scaffolds based on poly (L-lactic acid) (PLLA)/poly (amidoamine) (PAMAM-G2) dendrimer/gemini surfactant were fabricated for the enhancement of synergistic antibacterial activities. The second generation of poly (amidoamine) (PAMAM-G2) and cationic gemini surfactant were utilized to functionalize the optimum electrospun scaffolds. The gelatination process was utilized to improve the wettability of PLLA scaffolds to extend cell attachment and cell proliferation. PLLA nanofibrous scaffolds were characterized by energy dispersion x-ray, scanning electron microscopy images, mechanical properties, water contact angle, Fourier transform infrared spectroscopy, zeta potential and antibacterial assessment. In vitro cell biocompatibility was evaluated by 3-(4, 5- dimethylthiazoyl-2-yl)-2, 5-diphenyltetrazolium bromide assay and morphology of PC-12 cells cultured on hybrid nanofibrous scaffolds and gelatinized ones. The results indicated that the optimum scaffolds could succe...
Supplemental Material, sj-pdf-1-jit-10.1177_15280837211048155 for Needleless electrospun mats bas... more Supplemental Material, sj-pdf-1-jit-10.1177_15280837211048155 for Needleless electrospun mats based on polyamidoamine dendritic polymers for encapsulation of essential oils in personal respiratory equipment by Maryam Mounesan, Somaye Akbari and Bogumil E Brycki in Journal of Industrial Textiles
The amine-terminated dendritic polymer as a novel class macromolecules attracts lots of attention... more The amine-terminated dendritic polymer as a novel class macromolecules attracts lots of attention due to various characteristics such as hyperbranched structures, multi-functional end groups, and interior cavities. In this chapter, amine-terminated dendritic polymers were applied on two famous natural fabrics, cotton and linen fabrics, to investigate the physical and chemical characteristic through measuring wrinkle recovery angel, tensile strength, air permeability, bending length, moisture regain, and dye adsorption based on statistical analysis. Dye adsorption and moisture regain of both modified fabrics increased which can be related to providing host–guest properties of dendritic polymers. Improvements of physical properties of fabrics were confirmed by enhancement of tensile strength and wrinkle recovery along with decreases of bending length. Furthermore, the antibacterial properties revealed on the modified fabrics due to the presence of abundant amine-terminated groups. The...
The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out... more The modification of poly (l-lactic acid) (PLLA) electrospun nanofibrous scaffolds was carried out by blending with second-generation poly amidoamine (PAMAM) for enhancement of their ionic conductivity. The samples containing PLLA and various amounts of PAMAM (1%, 3%, 5%, and 7% by wt.) were fabricated by electrospinning techniques. The electrospun fibers were characterized using scanning electron microscopy (SEM), porosity, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry, contact angle measurement, water uptake measurement, mechanical properties, and electrical properties. Furthermore, in vitro degradation study and cell viability assay were investigated in biomaterial applications. Creating amide groups through aminolysis reaction was confirmed by FTIR analysis successfully. The results reveal that adding PAMAM caused an increase in fiber diameter, crystallinity percentage, hydrophilicity, water absorption, elongation-at-break, and OE-mesenchymal s...
The development of efficient strategies for the removal of heavy metal ions from aqueous solution... more The development of efficient strategies for the removal of heavy metal ions from aqueous solutions is rapidly demanded as these contaminants are very toxic and carcinogenic and show detrimental effects on the living creatures. The main focus of the current study is on the preparation and assessment of electrospun adsorptive nanofiber membranes for the removal of toxic Ni(II) and Cu(II) from wastewater in the ultrafiltration process. Hydrothermally synthesized titanate nanotubes (TNT) was modified with thiol functional groups and then directly incorporated to the polyvinyl chloride nanofiber matrices via electrospinning process to fabricate an adsorptive membrane. The as-prepared electrospun nanofiber membranes and the nanoadsorbents were characterized with respect to the physiochemical properties, surface structure and morphology, applying XPS, FTIR, FESEM, EDX and TEM analysis and then, the membranes were evaluated in terms of the removal of the heavy metal ions in a continuous ultrafiltration mode. In adsorptive filtration of the metal ions, the effective factors including nanoadsorbents loading (0.5-1.5 wt%), initial metal ion concentration (60-150 mg/L), feed temperature (~25 °C-45 °C), presence of competing ion and reusability were investigated in the UF system where the membranes containing 1.5 wt% thiol-modified TNT and virgin TNT adsorbents demonstrated excellent removal efficiency compared to the other membranes. The Cu(II) and Ni(II) removal efficiency of the membrane containing 1.5 wt% functionalized TNT was 90% and 86.7%, respectively which was the highest ones. As was expected and due to the uniform dispersion and less aggregation of the modified TNT adsorbents on the large surface area of the electrospun nanofibers, more adsorption capacity of the nanoparticles can be exploited. Moreover, the strong affinity of the thiol functional groups toward the metal cations, these membranes removed metal contaminants more efficiently. Besides, the Cu(II) removal efficiency of the fabricated membranes didn't show any drastic changes in the presence of the competing ions. Furthermore, acceptable performance was achieved for the prepared membranes even after four adsorption/regeneration cycles in the continuous UF experiments, demonstrating the feasibility and effectiveness of the prepared adsorptive nanofiber membranes for the removal of heavy metal ions.
Highlights Controlling the aminolysis reaction onto the PLLA scaffolds is important issue Ami... more Highlights Controlling the aminolysis reaction onto the PLLA scaffolds is important issue Aminolyzed PLLA scaffolds using PPI dendrimer enhanced surface characteristic. Aminolyzed PLLA scaffolds prevents the necrosis of cells by reducing acidic pH value
Magnesium (Mg)-based alloys are biodegradable metallic biomaterials that show promise in minimizi... more Magnesium (Mg)-based alloys are biodegradable metallic biomaterials that show promise in minimizing the risks of permanent metallic implants. However, their clinical applications are restricted due to their rapid in vivo degradation and low surface hemocompatibilities. Surface modifications are critically important for controlling the corrosion rates of Mg-based alloys and improving their hemocompatibilities. In the present study, two heparinization methods were developed to simultaneously increase the corrosion resistance and hemocompatibility of the AZ31 Mg alloy. In the first method, the surface of the AZ31 alloy was modified by alkali–heat treatment and then aminolyzed by 3-amino propyltriethoxy silane (APTES), a self-assembly molecule, and heparin was grafted onto the aminolyzed surface. In the second method, before heparinization, polyamidoamine dendrimers (PAMAM4-4) were grafted onto the aminolyzed surface with APTES to increase the number of surface functional groups, and he...
International Journal of Environmental Science and Technology, 2021
In this study, two different methods were used to introduce functionalized graphene oxide (GO) on... more In this study, two different methods were used to introduce functionalized graphene oxide (GO) onto the surface of nanofiltration (NF) membrane to improve its performance for heavy metal removal. The first method was based on coating in which the surface of NF membrane was coated with cross-linked GO, while the second method was introducing GO into monomer solution during interfacial polymerization. The efficiency of different methods was then compared by characterizing membrane physiochemical properties, as well as separation performance. With regard to performances, the water flux of TFN-i2 membrane (with GOs incorporated into thin layer) was reported to be 95 L/m2 h compared to 75 L/m2 h found in the TFN-c2 membrane (with GOs coated on the surface) at 8 bar. Both modified membranes exhibited higher water flux than the control membrane without GO incorporation (40 L/m2 h). Although the water flux of TFN-c2 membrane was lower, it achieved higher cobalt removal (97%) than that of TFN-i2 membrane (73%) due to its higher negative surface charge that improved separation via the Donnan exclusion effect.
Gemini surfactants consist of two cationic monomers of a surfactant linked together with a spacer... more Gemini surfactants consist of two cationic monomers of a surfactant linked together with a spacer. The specific structure of a cationic gemini surfactant is the reason for both its high surface activity and its ability to decrease the surface tension of water. The high surface activity and unique structure of gemini surfactants result in outstanding properties, including antibacterial and antifungal activity, anticorrosion properties, unique aggregation behaviour, the ability to form various structures reversibly in response to environmental conditions, and interactions with biomacromolecules such as DNA and proteins. These properties can be tailored by selecting the optimal structure of a gemini surfactant in terms of the nature and length of its alkyl substituents, spacer, and head group. Additionally, regarding their properties, comparison with their monomeric counterparts demonstrates that gemini surfactants have higher performance efficacy at lower concentrations. Hence, less material is needed, and the toxicity is lower. However, there are some limitations regarding their biocompatibility that have led researchers to develop amino acid-based and sugar-based gemini surfactants. Owing to their remarkable properties, cationic gemini surfactants are promising candidates for bioapplications such as drug delivery systems, gene carriers, and biomaterial surface modification.
The ever-increasing concern of air pollution triggered by broad-spreading contagious disease, bio... more The ever-increasing concern of air pollution triggered by broad-spreading contagious disease, bioterrorism, and release of dust particles in the air is targeted to be addressed in this paper by developing a novel personal respiratory equipment (PRE). For this purpose, polyamidoamine dendritic polymers (PAMAMs) were utilized not only for encapsulating tea tree essential oil (TEO), an antimicrobial material, but also for battling against perilous bioaerosols. Furthermore, TEO is encapsulated inside both PAMAM and polyacrylonitrile (PAN) electrospun nanofibers. Results clarified that electrospun samples containing both TEO and PAMAM possess thinner nanofibers with 440 nm reduction in their average diameter, and pursuantly higher filtration efficiency against both NaCl and paraffin oil mist particles about 98% and well above 99%, respectively. Herein, the electrospinning method is employed first for high porosity, enhanced surface area to volume ratio, and interconnected pores of result...
Based on scientific reports, several pharmacological drugs have some defects which restrict their... more Based on scientific reports, several pharmacological drugs have some defects which restrict their application in biomedical and clinical application. Nanotechnology by introducing dendrimers as an interesting nanotech polymers circumvents these difficulties and facilitate their application in the biomedicine field. Dendrimers with outstanding three-dimensional structure and extraordinary properties such as monodispersity, highly branched, well-defined structure, interior cavity spaces, and numerous surface functional groups are the best candidate to be utilized as drug nanocarriers and ideal therapeutic agents delivery systems. In this book chapter, firstly, we discuss why and which features of dendrimers make them promising structures for conjugating and encapsulation of drugs, and then inherent toxicity as a barrier for their therapeutic efficiency is considered, and then surface functionalization as common ways to address this problem are described. In the following, an introduct...
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