In the ever-expanding field of conducting polymer research, functionalized graft hybrid copolymer... more In the ever-expanding field of conducting polymer research, functionalized graft hybrid copolymers have gained considerable interest in the biomedical engineering and biosensing applications, particularly. In the present work, a new biosensor based on conducting graft copolymer for the detection of phenolic compounds was developed. Thereby, a robust and novel material, namely "polythiophene-g-poly(ethylene glycol) with lateral amino groups" (PT-NH2-g-PEG) hybrid conducting polymer was synthesized via Suzuki condensation polymerization and characterized with (1)H NMR analysis, UV-vis spectroscopy, gel permeation chromatography (GPC) and fluorescence spectroscopy. PT-NH2-g-PEG architecture was then applied as an immobilization matrix to accomplish extended biosensing function. In a typical process, Laccase was utilized as a model enzyme for the detection of phenolic compounds. Detailed surface characterization of PT-NH2-g-PEG/Lac was performed by cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy, fluorescence microscopy and scanning electron microscopy measurements. Optimum pH and polymer amount were found to be pH 6.5 and 0.5 mg polymer, respectively, with the linear range of 0.0025-0.05 mM and 132.45 μA/mM sensitivity. The kinetic parameters of PT-NH2-g-PEG/Lac are 0.026 mM for Km(app) and 7.38 μA for Imax, respectively. Furthermore, the PT-NH2-g-PEG/Lac biofilm was retained 82% of its activity for 12 days indicating excellent recovery as tested with artificial wastewater.
ABSTRACT In the present study, two amphiphilic star-hyperbranched copolymers, poly(methyl methacr... more ABSTRACT In the present study, two amphiphilic star-hyperbranched copolymers, poly(methyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) (PMMA-b-PHEMA), with different hydrophilic PHEMA segment content (PMMA-b-PHEMA-1, and PMMA-b-PHEMA-2) were synthesized and their drug loading and release profiles were examined by using paclitaxel (PTX) as a model drug. Drug loading capacity and encapsulation efficiency were found to be similar in both polymers. Encapsulation efficiency found to be prominent with 98% and 98.5% for PMMA-b-PHEMA-1 and PMMA-b-PHEMA-2, respectively. On the other hand, drug release behaviors were varied in favor of the block copolymer comprising shorter PHEMA chains (PMMA-b-PHEMA-1). Additionally, to assess biological effects of PTX-loaded polymers, human non-small cell lung carcinoma (A549) cells were used. Cell viability and cell cycle analysis showed that both polymers were not toxic to the cells. Cytotoxic effects of PTX-loaded PMMA-b-PHEMA-1 on A 549 cells were higher (66.49% cell viability at 5.0 ng/mL PTX) than that of PMMA-b-PHEMA-2 (72.47% cell viability at 5.0 ng/mL PTX) consistent with the drug release experiments.
N-Acetyl-L-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block
copolymer (PM... more N-Acetyl-L-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously shown good applicability as a matrix for cell adhesion of cells from the Vero cell line (African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as an excellent immobilization matrix for biomolecule conjugation. Covalent binding of RGD (R: arginine, G: glycine, and D: aspartic acid) peptide sequence onto the PMMA-b-PCL-NAC-coated surface was performed via EDC chemistry. RGD-modified PMMA-b- PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell proliferation platform was used for selective ‘‘integrin avb3-mediated cell adhesion and biosensing studies. Both optical and electrochemical techniques were used to monitor the adhesion differences between ‘‘integrin avb3’’ receptor positive and negative cell lines on to the designed biofunctional surfaces.
The present work is the first work that includes the use of glycine (Gly), lysine (Lys) and gluta... more The present work is the first work that includes the use of glycine (Gly), lysine (Lys) and glutamic acid (Glu) modified clay mineral matrices in the biosensors. For this purpose, initially, Gly, Lys and Glu were intercalated with montmorillonite (Mt), thus, various modified Mts were obtained. These modified materials were then characterized via X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential and thermal gravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM). In order to investigate the applicability of amino acid modified clay minerals in biosensor area, glucose oxidase (GOx) was selected as the model enzyme and GOx based biosensor was prepared. After immobilizing the enzyme with amino acid modified Mt onto a glassy carbon electrode, working conditions like pH and modifier type were optimized. Among the modified Mts, Gly-Mt was the optimum clay mineral type and pH 4.0 was the optimum pH value. Then analytical characteristics were examined under optimum experimental conditions. Linear range of optimum sensor design was 0.1 – 1.0 mM within kinetic parameters of immobilized enzyme Km app= 0.7 mM, Imax =107.8 nA. Finally, developed biosensor was applied to real samples where the results were compared with a spectrophotometric reference method.
Most medicinal and pharmaceutical herbal extracts are poorly soluble in aqueous moieties and have... more Most medicinal and pharmaceutical herbal extracts are poorly soluble in aqueous moieties and have reduced adsorption by living cells. Liposomal encapsulation of those so called phytosomes could be a solution to overcome this problem. Meanwhile, much research shows that metallic nanoparticles such as gold nanoparticles (AuNPs) exhibit biological activity such as wound healing and antioxidant properties on living cells. Here, we constructed a novel liposomal formulation by encapsulating both Calendula officinalis extract and AuNPs. After the preparation of vesicles using the traditional thin film hydration method within extrusion, the resulting AuNP–phytosomes were characterized by dynamic light scattering size measurements, zeta potential and atomic force microscopy. These vesicles are less than 100 nm in size and have a high encapsulation efficiency for chlorogenic acid and quercetin as the model major molecules of Calendula extract. Furthermore, AuNP–phytosomes exhibited antioxidant and wound healing activity significantly according to the free forms of each encapsulated material and the plain liposome as well as the phytosome form. Moreover, the cellular interactions of the vesicles were monitored using the nano-vesicles prepared by Texas-Red labelled lipids under fluorescence microscopy.
A folic acid (FA) modified poly(epsilon-caprolactone)/clay nanocomposite (PCL/MMT–(CH2CH2OH)2–FA)... more A folic acid (FA) modified poly(epsilon-caprolactone)/clay nanocomposite (PCL/MMT–(CH2CH2OH)2–FA) resulting in selective cell adhesion and proliferation was synthesized and characterized as a cell culture and biosensing platform. For this purpose, first the FA modified clay (MMT–(CH2CH2OH)2–FA) was prepared by treating the organo-modified clay, Cloisite 30B [MMT–(CH2CH2OH)2] with FA in chloroform at 60 C. Subsequent ring opening polymerization of 3-caprolactone in the presence of tin octoate (Sn(Oct)2) using MMT–(CH2CH2OH)2–FA at 110 C resulted in the formation of MMT–(CH2CH2OH)2–FA with an exfoliated clay structure. The structures of intermediates and the final nanocomposite were investigated in detail by FT-IR spectral analysis and DSC, TGA, XRD, SEM and AFM measurements. The combination of FA, PCL and clay provides a simple and versatile route to surfaces that allows controlled and selective cell adhesion and proliferation. FA receptor-positive HeLa and negative A549 cells were used to prove the selectivity of the modified surfaces. Both microscopy and electrochemical sensing techniques were applied to show the differences in cell adherence on the modified and pristine clay platforms. This approach is expected to be adapted into various bio-applications such as ‘cell culture on chip’, biosensors and design of tools for targeted diagnosis or therapy.
A novel and efficient approach for the preparation of enriched herbal formulations was described ... more A novel and efficient approach for the preparation of enriched herbal formulations was described andtheir potential applications including wound healing and antioxidant activity (cell based and cell free)were investigated via in vitro cell culture studies. Nigella sativa oil was enriched with Calendula officinalisextract and lipoic acid capped gold nanoparticles (AuNP–LA) using nanoemulsion systems. The com-bination of these bio-active compounds was used to design oil in water (O/W) and water in oil (W/O)emulsions. The resulted emulsions were characterized by particle size measurements. The phenolic con-tent of each nanoemulsion was examined by using both colorimetric assay and chromatographic analyses.Two different methods containing cell free chemical assay (1-diphenyl-2-picrylhydrazyl method) and cellbased antioxidant activity test were used to evaluate the antioxidant capacities. In order to investigatethe bio-activities of the herbal formulations, in vitro cell culture experiments, including cytotoxicity,scratch assay, antioxidant activity and cell proliferation were carried out using Vero cell line as a modelcell line. Furthermore, to monitor localization of the nanoemulsions after application of the cell cul-ture, the cell images were monitored via fluorescence microscope after FITC labeling. All data confirmedthat the enriched N. sativa formulations exhibited better antioxidant and wound healing activity than N.sativa emulsion without any enrichment. In conclusion, the incorporation of AuNP–LA and C. officinalisextract into the N. sativa emulsions significantly increased the bio-activities. The present work may sup-port further studies about using the other bio-active agents for the enrichment of herbal preparations tostrengthen their activities.
In the ever-expanding field of conducting polymer research, functionalized graft hybrid copolymer... more In the ever-expanding field of conducting polymer research, functionalized graft hybrid copolymers have gained considerable interest in the biomedical engineering and biosensing applications, particularly. In the present work, a new biosensor based on conducting graft copolymer for the detection of phenolic compounds was developed. Thereby, a robust and novel material, namely "polythiophene-g-poly(ethylene glycol) with lateral amino groups" (PT-NH2-g-PEG) hybrid conducting polymer was synthesized via Suzuki condensation polymerization and characterized with (1)H NMR analysis, UV-vis spectroscopy, gel permeation chromatography (GPC) and fluorescence spectroscopy. PT-NH2-g-PEG architecture was then applied as an immobilization matrix to accomplish extended biosensing function. In a typical process, Laccase was utilized as a model enzyme for the detection of phenolic compounds. Detailed surface characterization of PT-NH2-g-PEG/Lac was performed by cyclic voltammetry, electrochemical impedance spectroscopy, atomic force microscopy, fluorescence microscopy and scanning electron microscopy measurements. Optimum pH and polymer amount were found to be pH 6.5 and 0.5 mg polymer, respectively, with the linear range of 0.0025-0.05 mM and 132.45 μA/mM sensitivity. The kinetic parameters of PT-NH2-g-PEG/Lac are 0.026 mM for Km(app) and 7.38 μA for Imax, respectively. Furthermore, the PT-NH2-g-PEG/Lac biofilm was retained 82% of its activity for 12 days indicating excellent recovery as tested with artificial wastewater.
ABSTRACT In the present study, two amphiphilic star-hyperbranched copolymers, poly(methyl methacr... more ABSTRACT In the present study, two amphiphilic star-hyperbranched copolymers, poly(methyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) (PMMA-b-PHEMA), with different hydrophilic PHEMA segment content (PMMA-b-PHEMA-1, and PMMA-b-PHEMA-2) were synthesized and their drug loading and release profiles were examined by using paclitaxel (PTX) as a model drug. Drug loading capacity and encapsulation efficiency were found to be similar in both polymers. Encapsulation efficiency found to be prominent with 98% and 98.5% for PMMA-b-PHEMA-1 and PMMA-b-PHEMA-2, respectively. On the other hand, drug release behaviors were varied in favor of the block copolymer comprising shorter PHEMA chains (PMMA-b-PHEMA-1). Additionally, to assess biological effects of PTX-loaded polymers, human non-small cell lung carcinoma (A549) cells were used. Cell viability and cell cycle analysis showed that both polymers were not toxic to the cells. Cytotoxic effects of PTX-loaded PMMA-b-PHEMA-1 on A 549 cells were higher (66.49% cell viability at 5.0 ng/mL PTX) than that of PMMA-b-PHEMA-2 (72.47% cell viability at 5.0 ng/mL PTX) consistent with the drug release experiments.
N-Acetyl-L-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block
copolymer (PM... more N-Acetyl-L-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously shown good applicability as a matrix for cell adhesion of cells from the Vero cell line (African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as an excellent immobilization matrix for biomolecule conjugation. Covalent binding of RGD (R: arginine, G: glycine, and D: aspartic acid) peptide sequence onto the PMMA-b-PCL-NAC-coated surface was performed via EDC chemistry. RGD-modified PMMA-b- PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell proliferation platform was used for selective ‘‘integrin avb3-mediated cell adhesion and biosensing studies. Both optical and electrochemical techniques were used to monitor the adhesion differences between ‘‘integrin avb3’’ receptor positive and negative cell lines on to the designed biofunctional surfaces.
The present work is the first work that includes the use of glycine (Gly), lysine (Lys) and gluta... more The present work is the first work that includes the use of glycine (Gly), lysine (Lys) and glutamic acid (Glu) modified clay mineral matrices in the biosensors. For this purpose, initially, Gly, Lys and Glu were intercalated with montmorillonite (Mt), thus, various modified Mts were obtained. These modified materials were then characterized via X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential and thermal gravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM). In order to investigate the applicability of amino acid modified clay minerals in biosensor area, glucose oxidase (GOx) was selected as the model enzyme and GOx based biosensor was prepared. After immobilizing the enzyme with amino acid modified Mt onto a glassy carbon electrode, working conditions like pH and modifier type were optimized. Among the modified Mts, Gly-Mt was the optimum clay mineral type and pH 4.0 was the optimum pH value. Then analytical characteristics were examined under optimum experimental conditions. Linear range of optimum sensor design was 0.1 – 1.0 mM within kinetic parameters of immobilized enzyme Km app= 0.7 mM, Imax =107.8 nA. Finally, developed biosensor was applied to real samples where the results were compared with a spectrophotometric reference method.
Most medicinal and pharmaceutical herbal extracts are poorly soluble in aqueous moieties and have... more Most medicinal and pharmaceutical herbal extracts are poorly soluble in aqueous moieties and have reduced adsorption by living cells. Liposomal encapsulation of those so called phytosomes could be a solution to overcome this problem. Meanwhile, much research shows that metallic nanoparticles such as gold nanoparticles (AuNPs) exhibit biological activity such as wound healing and antioxidant properties on living cells. Here, we constructed a novel liposomal formulation by encapsulating both Calendula officinalis extract and AuNPs. After the preparation of vesicles using the traditional thin film hydration method within extrusion, the resulting AuNP–phytosomes were characterized by dynamic light scattering size measurements, zeta potential and atomic force microscopy. These vesicles are less than 100 nm in size and have a high encapsulation efficiency for chlorogenic acid and quercetin as the model major molecules of Calendula extract. Furthermore, AuNP–phytosomes exhibited antioxidant and wound healing activity significantly according to the free forms of each encapsulated material and the plain liposome as well as the phytosome form. Moreover, the cellular interactions of the vesicles were monitored using the nano-vesicles prepared by Texas-Red labelled lipids under fluorescence microscopy.
A folic acid (FA) modified poly(epsilon-caprolactone)/clay nanocomposite (PCL/MMT–(CH2CH2OH)2–FA)... more A folic acid (FA) modified poly(epsilon-caprolactone)/clay nanocomposite (PCL/MMT–(CH2CH2OH)2–FA) resulting in selective cell adhesion and proliferation was synthesized and characterized as a cell culture and biosensing platform. For this purpose, first the FA modified clay (MMT–(CH2CH2OH)2–FA) was prepared by treating the organo-modified clay, Cloisite 30B [MMT–(CH2CH2OH)2] with FA in chloroform at 60 C. Subsequent ring opening polymerization of 3-caprolactone in the presence of tin octoate (Sn(Oct)2) using MMT–(CH2CH2OH)2–FA at 110 C resulted in the formation of MMT–(CH2CH2OH)2–FA with an exfoliated clay structure. The structures of intermediates and the final nanocomposite were investigated in detail by FT-IR spectral analysis and DSC, TGA, XRD, SEM and AFM measurements. The combination of FA, PCL and clay provides a simple and versatile route to surfaces that allows controlled and selective cell adhesion and proliferation. FA receptor-positive HeLa and negative A549 cells were used to prove the selectivity of the modified surfaces. Both microscopy and electrochemical sensing techniques were applied to show the differences in cell adherence on the modified and pristine clay platforms. This approach is expected to be adapted into various bio-applications such as ‘cell culture on chip’, biosensors and design of tools for targeted diagnosis or therapy.
A novel and efficient approach for the preparation of enriched herbal formulations was described ... more A novel and efficient approach for the preparation of enriched herbal formulations was described andtheir potential applications including wound healing and antioxidant activity (cell based and cell free)were investigated via in vitro cell culture studies. Nigella sativa oil was enriched with Calendula officinalisextract and lipoic acid capped gold nanoparticles (AuNP–LA) using nanoemulsion systems. The com-bination of these bio-active compounds was used to design oil in water (O/W) and water in oil (W/O)emulsions. The resulted emulsions were characterized by particle size measurements. The phenolic con-tent of each nanoemulsion was examined by using both colorimetric assay and chromatographic analyses.Two different methods containing cell free chemical assay (1-diphenyl-2-picrylhydrazyl method) and cellbased antioxidant activity test were used to evaluate the antioxidant capacities. In order to investigatethe bio-activities of the herbal formulations, in vitro cell culture experiments, including cytotoxicity,scratch assay, antioxidant activity and cell proliferation were carried out using Vero cell line as a modelcell line. Furthermore, to monitor localization of the nanoemulsions after application of the cell cul-ture, the cell images were monitored via fluorescence microscope after FITC labeling. All data confirmedthat the enriched N. sativa formulations exhibited better antioxidant and wound healing activity than N.sativa emulsion without any enrichment. In conclusion, the incorporation of AuNP–LA and C. officinalisextract into the N. sativa emulsions significantly increased the bio-activities. The present work may sup-port further studies about using the other bio-active agents for the enrichment of herbal preparations tostrengthen their activities.
Uploads
Papers by Bilal Demir
copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced
sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously
shown good applicability as a matrix for cell adhesion of cells from the Vero cell line
(African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as
an excellent immobilization matrix for biomolecule
conjugation. Covalent binding of RGD (R: arginine,
G: glycine, and D: aspartic acid) peptide sequence
onto the PMMA-b-PCL-NAC-coated surface was performed
via EDC chemistry. RGD-modified PMMA-b-
PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell
proliferation platform was used for selective ‘‘integrin
avb3-mediated cell adhesion and biosensing
studies. Both optical and electrochemical techniques
were used to monitor the adhesion differences
between ‘‘integrin avb3’’ receptor positive and
negative cell lines on to the designed biofunctional
surfaces.
(Glu) modified clay mineral matrices in the biosensors. For this purpose, initially, Gly, Lys and Glu were
intercalated with montmorillonite (Mt), thus, various modified Mts were obtained. These modified
materials were then characterized via X-ray diffraction, Fourier transform infrared spectroscopy, zeta
potential and thermal gravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM). In order
to investigate the applicability of amino acid modified clay minerals in biosensor area, glucose oxidase
(GOx) was selected as the model enzyme and GOx based biosensor was prepared. After immobilizing the
enzyme with amino acid modified Mt onto a glassy carbon electrode, working conditions like pH and
modifier type were optimized. Among the modified Mts, Gly-Mt was the optimum clay mineral type and
pH 4.0 was the optimum pH value. Then analytical characteristics were examined under optimum
experimental conditions. Linear range of optimum sensor design was 0.1 – 1.0 mM within kinetic
parameters of immobilized enzyme Km
app= 0.7 mM, Imax =107.8 nA. Finally, developed biosensor was
applied to real samples where the results were compared with a spectrophotometric reference method.
reduced adsorption by living cells. Liposomal encapsulation of those so called phytosomes could be a
solution to overcome this problem. Meanwhile, much research shows that metallic nanoparticles such as
gold nanoparticles (AuNPs) exhibit biological activity such as wound healing and antioxidant properties
on living cells. Here, we constructed a novel liposomal formulation by encapsulating both Calendula
officinalis extract and AuNPs. After the preparation of vesicles using the traditional thin film hydration
method within extrusion, the resulting AuNP–phytosomes were characterized by dynamic light
scattering size measurements, zeta potential and atomic force microscopy. These vesicles are less than
100 nm in size and have a high encapsulation efficiency for chlorogenic acid and quercetin as the model
major molecules of Calendula extract. Furthermore, AuNP–phytosomes exhibited antioxidant and wound
healing activity significantly according to the free forms of each encapsulated material and the plain
liposome as well as the phytosome form. Moreover, the cellular interactions of the vesicles were
monitored using the nano-vesicles prepared by Texas-Red labelled lipids under fluorescence microscopy.
resulting in selective cell adhesion and proliferation was synthesized and characterized as a cell culture
and biosensing platform. For this purpose, first the FA modified clay (MMT–(CH2CH2OH)2–FA) was
prepared by treating the organo-modified clay, Cloisite 30B [MMT–(CH2CH2OH)2] with FA in chloroform
at 60 C. Subsequent ring opening polymerization of 3-caprolactone in the presence of tin octoate
(Sn(Oct)2) using MMT–(CH2CH2OH)2–FA at 110 C resulted in the formation of MMT–(CH2CH2OH)2–FA
with an exfoliated clay structure. The structures of intermediates and the final nanocomposite were
investigated in detail by FT-IR spectral analysis and DSC, TGA, XRD, SEM and AFM measurements. The
combination of FA, PCL and clay provides a simple and versatile route to surfaces that allows controlled
and selective cell adhesion and proliferation. FA receptor-positive HeLa and negative A549 cells were
used to prove the selectivity of the modified surfaces. Both microscopy and electrochemical sensing
techniques were applied to show the differences in cell adherence on the modified and pristine clay
platforms. This approach is expected to be adapted into various bio-applications such as ‘cell culture on
chip’, biosensors and design of tools for targeted diagnosis or therapy.
copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced
sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously
shown good applicability as a matrix for cell adhesion of cells from the Vero cell line
(African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as
an excellent immobilization matrix for biomolecule
conjugation. Covalent binding of RGD (R: arginine,
G: glycine, and D: aspartic acid) peptide sequence
onto the PMMA-b-PCL-NAC-coated surface was performed
via EDC chemistry. RGD-modified PMMA-b-
PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell
proliferation platform was used for selective ‘‘integrin
avb3-mediated cell adhesion and biosensing
studies. Both optical and electrochemical techniques
were used to monitor the adhesion differences
between ‘‘integrin avb3’’ receptor positive and
negative cell lines on to the designed biofunctional
surfaces.
(Glu) modified clay mineral matrices in the biosensors. For this purpose, initially, Gly, Lys and Glu were
intercalated with montmorillonite (Mt), thus, various modified Mts were obtained. These modified
materials were then characterized via X-ray diffraction, Fourier transform infrared spectroscopy, zeta
potential and thermal gravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM). In order
to investigate the applicability of amino acid modified clay minerals in biosensor area, glucose oxidase
(GOx) was selected as the model enzyme and GOx based biosensor was prepared. After immobilizing the
enzyme with amino acid modified Mt onto a glassy carbon electrode, working conditions like pH and
modifier type were optimized. Among the modified Mts, Gly-Mt was the optimum clay mineral type and
pH 4.0 was the optimum pH value. Then analytical characteristics were examined under optimum
experimental conditions. Linear range of optimum sensor design was 0.1 – 1.0 mM within kinetic
parameters of immobilized enzyme Km
app= 0.7 mM, Imax =107.8 nA. Finally, developed biosensor was
applied to real samples where the results were compared with a spectrophotometric reference method.
reduced adsorption by living cells. Liposomal encapsulation of those so called phytosomes could be a
solution to overcome this problem. Meanwhile, much research shows that metallic nanoparticles such as
gold nanoparticles (AuNPs) exhibit biological activity such as wound healing and antioxidant properties
on living cells. Here, we constructed a novel liposomal formulation by encapsulating both Calendula
officinalis extract and AuNPs. After the preparation of vesicles using the traditional thin film hydration
method within extrusion, the resulting AuNP–phytosomes were characterized by dynamic light
scattering size measurements, zeta potential and atomic force microscopy. These vesicles are less than
100 nm in size and have a high encapsulation efficiency for chlorogenic acid and quercetin as the model
major molecules of Calendula extract. Furthermore, AuNP–phytosomes exhibited antioxidant and wound
healing activity significantly according to the free forms of each encapsulated material and the plain
liposome as well as the phytosome form. Moreover, the cellular interactions of the vesicles were
monitored using the nano-vesicles prepared by Texas-Red labelled lipids under fluorescence microscopy.
resulting in selective cell adhesion and proliferation was synthesized and characterized as a cell culture
and biosensing platform. For this purpose, first the FA modified clay (MMT–(CH2CH2OH)2–FA) was
prepared by treating the organo-modified clay, Cloisite 30B [MMT–(CH2CH2OH)2] with FA in chloroform
at 60 C. Subsequent ring opening polymerization of 3-caprolactone in the presence of tin octoate
(Sn(Oct)2) using MMT–(CH2CH2OH)2–FA at 110 C resulted in the formation of MMT–(CH2CH2OH)2–FA
with an exfoliated clay structure. The structures of intermediates and the final nanocomposite were
investigated in detail by FT-IR spectral analysis and DSC, TGA, XRD, SEM and AFM measurements. The
combination of FA, PCL and clay provides a simple and versatile route to surfaces that allows controlled
and selective cell adhesion and proliferation. FA receptor-positive HeLa and negative A549 cells were
used to prove the selectivity of the modified surfaces. Both microscopy and electrochemical sensing
techniques were applied to show the differences in cell adherence on the modified and pristine clay
platforms. This approach is expected to be adapted into various bio-applications such as ‘cell culture on
chip’, biosensors and design of tools for targeted diagnosis or therapy.