In parallel with recent developments in communications, nanotechnology and materials sciences, th... more In parallel with recent developments in communications, nanotechnology and materials sciences, there has been extraordinary growth in the area of biosensors, with almost half of the total number of papers ever published (1962-2015) appearing in the last five-years (2010-2015). Molecular imprinting offers a route to the creation of specific and selective cavities in a 3D-polymeric network, which are complementary not only to the size and shape of a target species, but also provide interaction points and a coordination sphere around the template molecule. Given the challenges facing biosensor technologists, it is natural that this approach to create potentially highly stable synthetic ligands as an alternative to, or to compliment natural receptors, should emerge as a key line of interdisciplinary research. Despite the profuse amount of recent literature on molecularly-imprinted polymers (MIPs) and some limited commercial activity, these promising materials still need to overcome some limitations before taking their place in analytical market. In this review, we have focused on the most promising advances in MIP-based biosensors to illustrate how close to market they really are. We present our material under five main sections covering computational design, polymerisation strategies, material combinations, recent sensor designs and manufacturing issues. Each section provides technical details and evaluates the effect on sensor performance.
l-Lysine imprinted poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-l-aspartic acid) [P(HEMA-co... more l-Lysine imprinted poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-l-aspartic acid) [P(HEMA-co-MAAsp)] cryogels were synthesized and characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, surface area measurements, swelling, and squeezing tests. Specific surface area for imprinted cryogel was 34.2m(2)/g while the value was 21.3m(2)/g for non-imprinted cryogel. IgG adsorption from aqueous solution was examined in continuous mode examining the factors effecting adsorption capacity such as pH, concentration, flow rate, temperature, ionic strength, and incubation time. 0.5M NaCl was used as desorption agent. The IgG adsorption capacity was determined as 55.1mg/g for 1.0mg/mL IgG original concentration at 25.0°C while pH and flow rate were 7.0 and 0.5mL/min, respectively. When human serum was used as IgG source, the removal of 90.4% of crude IgG was attained for 1/20 diluted plasma sample. The imprinted cryogel was used in ten successive cycles without significant loss in adsorption capacity. The cryogel was determined to be 1.79 times more selective to IgG than albumin and 1.45 times more selective than hemoglobin. The adsorption behavior well suited to Langmuir isotherm and the kinetics followed pseudo-second-order model. Thermodynamic parameters ΔH°, ΔS° and ΔG° for this adsorption process were also calculated.
Magnetic microparticles have many applications in various areas today. The aim of this study was ... more Magnetic microparticles have many applications in various areas today. The aim of this study was to develop hydrophobic magnetic microparticles as an alternative to traditional methods for high capacity and low cost removal of Victoria Blue R (VBR), which is valuable for industry and commercial, from wastewater and to determine the VBR adsorption ability of this adsorbent. Fe(II)–Co(II) double salt incorporated magnetic poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-tryptophan) [m-poly(HEMA-MATrp)] microparticles were synthesized and used as adsorbent. These microparticles were synthesized in aqueous dispersion medium via microemulsion polymerization using MATrp and HEMA monomers. Magnetic hydrophobic microparticles were characterized via Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. Adsorption experiments were conducted for different conditions (pH, interaction time, amount of microparticles, temperature, and ionic strength) in batch system. VBR adsorption capacity of magnetic hydrophobic microparticles was estimated as 89.46 μmol/g. Adsorption–desorption cycles were repeated 4 times, and there was no significant decrease for the adsorption capacity observed.
Http Dx Doi Org 10 1163 092050610x538731, Apr 2, 2012
The preparation of affinity membranes for application in antibody purification studies is describ... more The preparation of affinity membranes for application in antibody purification studies is described here. Protein-A-attached poly(hydroxyethyl methacrylate-N-methacryloyl-L-alanine) (PHEMAAL) membranes were produced by a photopolymerization technique and then characterized by swelling tests, surface area measurements, contact angle and scanning electron microscopy (SEM) studies. The water swelling ratio of the PHEMAAL membrane was 133.2%. PHEMAAL membranes have large pores with a size in the range of 5–10 μm. Protein A was covalently attached onto the PHEMAAL membranes via cyanogen bromide (CNBr) activation. Maximum protein A loading was 4.7 mg/g. There was a very low non-specific IgG adsorption onto the PHEMAAL membranes, about 0.38 mg/g. The maximum IgG adsorption on the PHEMAAL–protein A membrane was found to be 9.8 mg/g at pH 7.4 from aqueous solutions. Higher adsorption amount was observed from human plasma (up to 37.3 mg/g). Adsorbed IgG was eluted using 0.1 M glycine-HCl buffer (pH 3.5) with a purity of 93%. PHEMAAL–protein A membrane was used for repetitive adsorption/elution of IgG without noticeable loss in IgG adsorption amount after 10 cycles. The PHEMAAL–protein A membrane showed several advantages, such as simpler preparation procedure, good selectivity for IgG purification from human plasma and good stability throughout repeated adsorption–elution cycles.
ABSTRACT In this study, we aimed to synthesize specific filtration cartridges having selective re... more ABSTRACT In this study, we aimed to synthesize specific filtration cartridges having selective recognition sites against target molecules for separation interferon α-2b from aqueous solutions. So, molecular imprinting technology was combined with cryogel to achieve specific and rapid filtration of interferon α-2b through macroporous structure of cryogel network. In this purpose, recombinant interferon α-2b imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan) P(HEMATrp)/α-2bIFN cryogels were synthesized via free radical bulk polymerization under partially frozen conditions. After that, interferon α-2b filtration conditions were optimized while considering effective factors such as pH, initial concentration, temperature, centrifugation speed, salt concentration and types, and amount of precomplex incorporated. Selectivity parameters were also calculated. The selectivity coefficients of specific filtration cartridge for interferon/IgG, interferon/HSA, and interferon/insulin pairs were respectively 3.72, 7.09, and 10.67, those were greater than non-imprinted [P(HEMATrp)] filtration cartridge has. Finally, it was observed that specific cartridges could repeatedly adsorb interferon α-2b could in a short separation time without any significant decrease in the adsorption capacity.
The International journal of artificial organs, 2006
The aim of this study is to prepare ion-imprinted poly(2-hydroxyethyl methacrylate) (HEMA) based ... more The aim of this study is to prepare ion-imprinted poly(2-hydroxyethyl methacrylate) (HEMA) based membranes which can be used for the selective removal of Fe3+ ions from Fe3+-overdosed human plasma. N-methacryloyl-(L)-glutamic acid (MAGA) was chosen as the ion-complexing monomer. In the first step, Fe3+ was complexed with MAGA and then, the Fe3+-imprinted poly(HEMA-MAGA) membranes were prepared by UV-initiated photo-polymerization of HEMA and MAGA-Fe3+ complex in the presence of an initiator (benzoyl peroxide). After that, the template (i.e., Fe3+ ions) was removed by using 0.1 M EDTA solution at room temperature. The specific surface area of the Fe3+-imprinted poly(HEMA-MAGA) membranes was found to be 49.2 m2/g and the swelling ratio was 92%. According to the elemental analysis results, the polymeric membranes contained 145.7 micromol MAGA/g polymer. The maximum adsorption capacity was 164.2 micromol Fe3+/g membrane. The relative selectivity coefficients of ion-imprinted membranes f...
A facile colorimetric sensor array for detection of multiple toxic heavy metal ions (Hg(2+), Cd(2... more A facile colorimetric sensor array for detection of multiple toxic heavy metal ions (Hg(2+), Cd(2+), Fe(3+), Pb(2+), Al(3+), Cu(2+), and Cr(3+)) in water is demonstrated using 11-mercaptoundecanoic acid (MUA)-capped gold nanoparticles (AuNPs) and five amino acids (lysine, cysteine, histidine, tyrosine, and arginine). The presence of amino acids (which have functional groups that can form complexes with metal ions and MUA) regulates the aggregation of MUA-capped particles; it can either enhance or diminish the particle aggregation. The combinatorial colorimetric response of all channels of the sensor array (i.e., color change in each of AuNP and amino acid couples) enables naked-eye discrimination of all of the metal ions tested in this study with excellent selectivity.
Artificial Cells, Nanomedicine, and Biotechnology, 2015
In this study, a new molecular imprinting (MIP)-based monolithic cryogel column was prepared usin... more In this study, a new molecular imprinting (MIP)-based monolithic cryogel column was prepared using chemically crosslinked molecularly imprinted nanoparticles, to achieve a simplified chromatographic separation (SPE) for a model compound, L-glutamic acid (L-Glu). Cryogelation through crosslinking of imprinted nanoparticles forms stable monolithic cryogel columns. This technique reduces the leakage of nanoparticles and increases the surface area, while protecting the structural features of the cryogel for stable and efficient recognition of the template molecule. A non-imprinted monolithic cryogel column (NIP) was also prepared, using non-imprinted nanoparticles produced without the addition of L-Glu during polymerization. The molecularly imprinted monolithic cryogel column (MIP) indicates apparent recognition selectivity and a good adsorption capacity compared to the NIP. Also, we have achieved a significant increase in the adsorption capacity, using the advantage of high surface area of the nanoparticles.
Molecular imprinting is a polymerization technique that provides synthetic analogs for template m... more Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded.
ABSTRACT A hydrophobic group/comonomer N-methacryloyl-(l)-alanine (MAAL) containing 2-hydroxyethy... more ABSTRACT A hydrophobic group/comonomer N-methacryloyl-(l)-alanine (MAAL) containing 2-hydroxyethyl methacrylate (HEMA)-based magnetic hydrophobic nanoparticles was synthesized by using a microemulsion polymerization technique for immobilization of amyloglucosidase (AMG). The magnetic hydrophobic nanoparticles with an average diameter of 79 nm were characterized with Fourier transform infrared spectroscopy, transmission electron microscopy, zeta-size analysis, and electron spin resonance spectroscopy. Hereby, the effecting factors such as initial concentration of AMG, pH, and temperature on the immobilization were investigated. After determining the optimum immobilization conditions, the kinetic constants (KM and Vmax) and properties of free and immobilized AMG were investigated in batch studies. The maximum AMG adsorption capacity of the magnetic hydrophobic nanoparticles was 294.42 mg/g at pH 3.0. The optimum pH and temperature for free and immobilized AMG were found to be pH 5.0 and 60 °C. The KM value for immobilized AMG was higher than that of the free enzyme, whereas the Vmax value was lower for the immobilized AMG preparations.
The main problem in cancer chemotherapy is the cytotoxic side effects of therapeutics on healthy ... more The main problem in cancer chemotherapy is the cytotoxic side effects of therapeutics on healthy tissues and cells. The targeted drug delivery and nanotechnology are intensively investigated area to find new ways to solve, at least to reduce, these problems. Hereby, we have reported a new method inspired from both conventional military strategies and biorecognition in the body. In this respect, we have produced two fluorescent nano-drug systems with bitargeting and biorecognition properties, recognizing cancer cells and each other. The multiplexed nanostructures were interacted with HL-60 cells to show their efficiency for bitargeting, ambushing, timed, and double-controlled cancer cell apoptosis.
Procalcitonin (PCT) is a promising biomarker for identification of the origin and severity of sep... more Procalcitonin (PCT) is a promising biomarker for identification of the origin and severity of sepsis, which is a deadly body infection. In this work, we report the preparation of a surface plasmon resonance (SPR) biosensor which utilizes a molecular imprinted polymer surface for rapid and reliable detection of PCT. The molecular imprinted surface was prepared using a microcontact imprinting technique, in which PCT molecules were first immobilized onto a glass support and brought into contact with a solution of 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) on a SPR sensor, then the polymerization process was performed. After removal of the PCT molecules, specific molecular recognition sites were obtained, where PCT molecules can selectively rebind, only at the surface of the polymer matrix. PCT detection studies were carried out using PCT solutions in phosphate buffer and simulated blood plasma (SBP) at different concentrations. The SPR biosensor can detect very low concentrations (9.9 ng mL(-1)) of PCT within approximately 1 h, in both phosphate buffer and SBP. High selectivity of the biosensor against PCT was also demonstrated in the presence of several competitive proteins such as human serum albumin, myoglobin and cytochrome c.
In parallel with recent developments in communications, nanotechnology and materials sciences, th... more In parallel with recent developments in communications, nanotechnology and materials sciences, there has been extraordinary growth in the area of biosensors, with almost half of the total number of papers ever published (1962-2015) appearing in the last five-years (2010-2015). Molecular imprinting offers a route to the creation of specific and selective cavities in a 3D-polymeric network, which are complementary not only to the size and shape of a target species, but also provide interaction points and a coordination sphere around the template molecule. Given the challenges facing biosensor technologists, it is natural that this approach to create potentially highly stable synthetic ligands as an alternative to, or to compliment natural receptors, should emerge as a key line of interdisciplinary research. Despite the profuse amount of recent literature on molecularly-imprinted polymers (MIPs) and some limited commercial activity, these promising materials still need to overcome some limitations before taking their place in analytical market. In this review, we have focused on the most promising advances in MIP-based biosensors to illustrate how close to market they really are. We present our material under five main sections covering computational design, polymerisation strategies, material combinations, recent sensor designs and manufacturing issues. Each section provides technical details and evaluates the effect on sensor performance.
l-Lysine imprinted poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-l-aspartic acid) [P(HEMA-co... more l-Lysine imprinted poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-l-aspartic acid) [P(HEMA-co-MAAsp)] cryogels were synthesized and characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, surface area measurements, swelling, and squeezing tests. Specific surface area for imprinted cryogel was 34.2m(2)/g while the value was 21.3m(2)/g for non-imprinted cryogel. IgG adsorption from aqueous solution was examined in continuous mode examining the factors effecting adsorption capacity such as pH, concentration, flow rate, temperature, ionic strength, and incubation time. 0.5M NaCl was used as desorption agent. The IgG adsorption capacity was determined as 55.1mg/g for 1.0mg/mL IgG original concentration at 25.0°C while pH and flow rate were 7.0 and 0.5mL/min, respectively. When human serum was used as IgG source, the removal of 90.4% of crude IgG was attained for 1/20 diluted plasma sample. The imprinted cryogel was used in ten successive cycles without significant loss in adsorption capacity. The cryogel was determined to be 1.79 times more selective to IgG than albumin and 1.45 times more selective than hemoglobin. The adsorption behavior well suited to Langmuir isotherm and the kinetics followed pseudo-second-order model. Thermodynamic parameters ΔH°, ΔS° and ΔG° for this adsorption process were also calculated.
Magnetic microparticles have many applications in various areas today. The aim of this study was ... more Magnetic microparticles have many applications in various areas today. The aim of this study was to develop hydrophobic magnetic microparticles as an alternative to traditional methods for high capacity and low cost removal of Victoria Blue R (VBR), which is valuable for industry and commercial, from wastewater and to determine the VBR adsorption ability of this adsorbent. Fe(II)–Co(II) double salt incorporated magnetic poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-tryptophan) [m-poly(HEMA-MATrp)] microparticles were synthesized and used as adsorbent. These microparticles were synthesized in aqueous dispersion medium via microemulsion polymerization using MATrp and HEMA monomers. Magnetic hydrophobic microparticles were characterized via Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. Adsorption experiments were conducted for different conditions (pH, interaction time, amount of microparticles, temperature, and ionic strength) in batch system. VBR adsorption capacity of magnetic hydrophobic microparticles was estimated as 89.46 μmol/g. Adsorption–desorption cycles were repeated 4 times, and there was no significant decrease for the adsorption capacity observed.
Http Dx Doi Org 10 1163 092050610x538731, Apr 2, 2012
The preparation of affinity membranes for application in antibody purification studies is describ... more The preparation of affinity membranes for application in antibody purification studies is described here. Protein-A-attached poly(hydroxyethyl methacrylate-N-methacryloyl-L-alanine) (PHEMAAL) membranes were produced by a photopolymerization technique and then characterized by swelling tests, surface area measurements, contact angle and scanning electron microscopy (SEM) studies. The water swelling ratio of the PHEMAAL membrane was 133.2%. PHEMAAL membranes have large pores with a size in the range of 5–10 μm. Protein A was covalently attached onto the PHEMAAL membranes via cyanogen bromide (CNBr) activation. Maximum protein A loading was 4.7 mg/g. There was a very low non-specific IgG adsorption onto the PHEMAAL membranes, about 0.38 mg/g. The maximum IgG adsorption on the PHEMAAL–protein A membrane was found to be 9.8 mg/g at pH 7.4 from aqueous solutions. Higher adsorption amount was observed from human plasma (up to 37.3 mg/g). Adsorbed IgG was eluted using 0.1 M glycine-HCl buffer (pH 3.5) with a purity of 93%. PHEMAAL–protein A membrane was used for repetitive adsorption/elution of IgG without noticeable loss in IgG adsorption amount after 10 cycles. The PHEMAAL–protein A membrane showed several advantages, such as simpler preparation procedure, good selectivity for IgG purification from human plasma and good stability throughout repeated adsorption–elution cycles.
ABSTRACT In this study, we aimed to synthesize specific filtration cartridges having selective re... more ABSTRACT In this study, we aimed to synthesize specific filtration cartridges having selective recognition sites against target molecules for separation interferon α-2b from aqueous solutions. So, molecular imprinting technology was combined with cryogel to achieve specific and rapid filtration of interferon α-2b through macroporous structure of cryogel network. In this purpose, recombinant interferon α-2b imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan) P(HEMATrp)/α-2bIFN cryogels were synthesized via free radical bulk polymerization under partially frozen conditions. After that, interferon α-2b filtration conditions were optimized while considering effective factors such as pH, initial concentration, temperature, centrifugation speed, salt concentration and types, and amount of precomplex incorporated. Selectivity parameters were also calculated. The selectivity coefficients of specific filtration cartridge for interferon/IgG, interferon/HSA, and interferon/insulin pairs were respectively 3.72, 7.09, and 10.67, those were greater than non-imprinted [P(HEMATrp)] filtration cartridge has. Finally, it was observed that specific cartridges could repeatedly adsorb interferon α-2b could in a short separation time without any significant decrease in the adsorption capacity.
The International journal of artificial organs, 2006
The aim of this study is to prepare ion-imprinted poly(2-hydroxyethyl methacrylate) (HEMA) based ... more The aim of this study is to prepare ion-imprinted poly(2-hydroxyethyl methacrylate) (HEMA) based membranes which can be used for the selective removal of Fe3+ ions from Fe3+-overdosed human plasma. N-methacryloyl-(L)-glutamic acid (MAGA) was chosen as the ion-complexing monomer. In the first step, Fe3+ was complexed with MAGA and then, the Fe3+-imprinted poly(HEMA-MAGA) membranes were prepared by UV-initiated photo-polymerization of HEMA and MAGA-Fe3+ complex in the presence of an initiator (benzoyl peroxide). After that, the template (i.e., Fe3+ ions) was removed by using 0.1 M EDTA solution at room temperature. The specific surface area of the Fe3+-imprinted poly(HEMA-MAGA) membranes was found to be 49.2 m2/g and the swelling ratio was 92%. According to the elemental analysis results, the polymeric membranes contained 145.7 micromol MAGA/g polymer. The maximum adsorption capacity was 164.2 micromol Fe3+/g membrane. The relative selectivity coefficients of ion-imprinted membranes f...
A facile colorimetric sensor array for detection of multiple toxic heavy metal ions (Hg(2+), Cd(2... more A facile colorimetric sensor array for detection of multiple toxic heavy metal ions (Hg(2+), Cd(2+), Fe(3+), Pb(2+), Al(3+), Cu(2+), and Cr(3+)) in water is demonstrated using 11-mercaptoundecanoic acid (MUA)-capped gold nanoparticles (AuNPs) and five amino acids (lysine, cysteine, histidine, tyrosine, and arginine). The presence of amino acids (which have functional groups that can form complexes with metal ions and MUA) regulates the aggregation of MUA-capped particles; it can either enhance or diminish the particle aggregation. The combinatorial colorimetric response of all channels of the sensor array (i.e., color change in each of AuNP and amino acid couples) enables naked-eye discrimination of all of the metal ions tested in this study with excellent selectivity.
Artificial Cells, Nanomedicine, and Biotechnology, 2015
In this study, a new molecular imprinting (MIP)-based monolithic cryogel column was prepared usin... more In this study, a new molecular imprinting (MIP)-based monolithic cryogel column was prepared using chemically crosslinked molecularly imprinted nanoparticles, to achieve a simplified chromatographic separation (SPE) for a model compound, L-glutamic acid (L-Glu). Cryogelation through crosslinking of imprinted nanoparticles forms stable monolithic cryogel columns. This technique reduces the leakage of nanoparticles and increases the surface area, while protecting the structural features of the cryogel for stable and efficient recognition of the template molecule. A non-imprinted monolithic cryogel column (NIP) was also prepared, using non-imprinted nanoparticles produced without the addition of L-Glu during polymerization. The molecularly imprinted monolithic cryogel column (MIP) indicates apparent recognition selectivity and a good adsorption capacity compared to the NIP. Also, we have achieved a significant increase in the adsorption capacity, using the advantage of high surface area of the nanoparticles.
Molecular imprinting is a polymerization technique that provides synthetic analogs for template m... more Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded.
ABSTRACT A hydrophobic group/comonomer N-methacryloyl-(l)-alanine (MAAL) containing 2-hydroxyethy... more ABSTRACT A hydrophobic group/comonomer N-methacryloyl-(l)-alanine (MAAL) containing 2-hydroxyethyl methacrylate (HEMA)-based magnetic hydrophobic nanoparticles was synthesized by using a microemulsion polymerization technique for immobilization of amyloglucosidase (AMG). The magnetic hydrophobic nanoparticles with an average diameter of 79 nm were characterized with Fourier transform infrared spectroscopy, transmission electron microscopy, zeta-size analysis, and electron spin resonance spectroscopy. Hereby, the effecting factors such as initial concentration of AMG, pH, and temperature on the immobilization were investigated. After determining the optimum immobilization conditions, the kinetic constants (KM and Vmax) and properties of free and immobilized AMG were investigated in batch studies. The maximum AMG adsorption capacity of the magnetic hydrophobic nanoparticles was 294.42 mg/g at pH 3.0. The optimum pH and temperature for free and immobilized AMG were found to be pH 5.0 and 60 °C. The KM value for immobilized AMG was higher than that of the free enzyme, whereas the Vmax value was lower for the immobilized AMG preparations.
The main problem in cancer chemotherapy is the cytotoxic side effects of therapeutics on healthy ... more The main problem in cancer chemotherapy is the cytotoxic side effects of therapeutics on healthy tissues and cells. The targeted drug delivery and nanotechnology are intensively investigated area to find new ways to solve, at least to reduce, these problems. Hereby, we have reported a new method inspired from both conventional military strategies and biorecognition in the body. In this respect, we have produced two fluorescent nano-drug systems with bitargeting and biorecognition properties, recognizing cancer cells and each other. The multiplexed nanostructures were interacted with HL-60 cells to show their efficiency for bitargeting, ambushing, timed, and double-controlled cancer cell apoptosis.
Procalcitonin (PCT) is a promising biomarker for identification of the origin and severity of sep... more Procalcitonin (PCT) is a promising biomarker for identification of the origin and severity of sepsis, which is a deadly body infection. In this work, we report the preparation of a surface plasmon resonance (SPR) biosensor which utilizes a molecular imprinted polymer surface for rapid and reliable detection of PCT. The molecular imprinted surface was prepared using a microcontact imprinting technique, in which PCT molecules were first immobilized onto a glass support and brought into contact with a solution of 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) on a SPR sensor, then the polymerization process was performed. After removal of the PCT molecules, specific molecular recognition sites were obtained, where PCT molecules can selectively rebind, only at the surface of the polymer matrix. PCT detection studies were carried out using PCT solutions in phosphate buffer and simulated blood plasma (SBP) at different concentrations. The SPR biosensor can detect very low concentrations (9.9 ng mL(-1)) of PCT within approximately 1 h, in both phosphate buffer and SBP. High selectivity of the biosensor against PCT was also demonstrated in the presence of several competitive proteins such as human serum albumin, myoglobin and cytochrome c.
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Papers by Lokman Uzun