In this paper,we demonstrate the application of Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC)technique to rapid and selective crystallization of a small drug compound.i.e.acetaminophen....In this paper,we demonstrate the application of Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC)technique to rapid and selective crystallization of a small drug compound.i.e.acetaminophen.Subsequent characterization of the crystals by optical microscopy,powder X-ray diffraction(PXRD)and Raman spectroscopy showed quantitatively selective growth of different crystal forms at various experimental conditions.Acetaminophen crystals were grown predominantly as Form I(99%)on blank glass slides at room temperature.Form II crystals with 39%purity grown on SIFs using microwave energy.展开更多
We describe the design and the use of a circular poly(methyl methacrylate)(PMMA)crystallization platform capable of processing 21 samples in Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC...We describe the design and the use of a circular poly(methyl methacrylate)(PMMA)crystallization platform capable of processing 21 samples in Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC).The PMMA platforms were modified with silver nanoparticle films(SNFs)to generate a microwave-induced temperature gradient between the solvent and the SNFs due to the marked differences in their physical properties.Since amino acids only chemisorb on to silver on the PMMA platform,SNFs served as selective and heterogeneous nucleation sites for amino acids.Theoretical simulations for electric field and temperature distributions inside a microwave cavity equipped with a PMMA platform were carried out to determine the optimum experimental conditions,i.e.,temperature variations and placement of the PMMA platform inside a microwave cavity.In addition,the actual temperature profiles of the amino acid solutions were monitored for the duration of the crystallization experiments carried out at room temperature and during microwave heating.The crystallization of five amino acids(L-threonine,L-histidine,L-leucine,L-serine and L-valine-HCl)at room temperature(control experiment)and using MA-MAEC were followed by optical microscopy.The induction time and crystal growth rates for all amino acids were determined.Using MA-MAEC,for all amino acids the induction times were significantly reduced(up to~8-fold)and the crystal growth rates were increased(up to~50-fold)as compared to room temperature crystallization,respectively.All crystals were characterized by Raman spectroscopy and powder x-ray diffraction,which demonstrated that the crystal structures of all amino acids grown at room temperature and using MA-MAEC were similar.展开更多
We demonstrate the design and the proof-of-concept use of a new,circular poly(methyl methacrylate)-based bioassay platform(PMMA platform),which affords for the rapid processing of 16 samples at once.The circular PMMA ...We demonstrate the design and the proof-of-concept use of a new,circular poly(methyl methacrylate)-based bioassay platform(PMMA platform),which affords for the rapid processing of 16 samples at once.The circular PMMA platform(5 cm in diameter)was coated with a silver nanoparticle film to accelerate the bioassay steps by microwave heating.A model colorimetric bioassay for biotinylated albumin(using streptavidin-labeled horse radish peroxidase)was performed on the PMMA platform coated with and without silver nanoparticles(a control experiment),and at room temperature and using microwave heating.It was shown that the simulated temperature profile of the PMMA platform during microwave heating were comparable to the real-time temperature profile during actual microwave heating of the constructed PMMA platform in a commercial microwave oven.The model colorimetric bioassay for biotinylated albumin was successfully completed in~2 min(total assay time)using microwave heating,as compared to 90 min at room temperature(total assay time),which indicates a~45-fold decrease in assay time.Our PMMA platform design afforded for significant reduction in non-specific interactions and low background signal as compared to non-silvered PMMA surfaces when employed in a microwave-accelerated bioassay carried out in a conventional microwave cavity.展开更多
In this study,we demonstrated a unique application of our Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC)technique for the de-crystallization of uric acid crystals,which causes gout in hu...In this study,we demonstrated a unique application of our Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC)technique for the de-crystallization of uric acid crystals,which causes gout in humans when monosodium urate crystals accumulate in the synovial fluid found in the joints of bones.Given the shortcomings of the existing treatments for gout,we investigated whether the MA-MAEC technique can offer an alternative solution to the treatment of gout.Our technique is based on the use of metal nanoparticles(i.e.,gold colloids)with low microwave heating to accelerate the de-crystallization process.In this regard,we employed a two-step process;(i)crystallization of uric acid on glass slides,which act as a solid platform to mimic a bone,(ii)de-crystallization of uric acid crystals on glass slides with the addition of gold colloids and low power microwave heating,which act as“nano-bullets”when microwave heated in a solution.We observed that the size and number of the uric acid crystals were reduced by>60%within 10 minutes of low power microwave heating.In addition,the use of gold colloids without microwave heating(i.e.control experiment)did not result in the de-crystallization of the uric acid crystals,which proves the utility of our MA-MAEC technique in the de-crystallization of uric acid.展开更多
Tumor detection can be carried out via the detection of proteins,such as p53,which is known to play vital role in more than 50%of all cancers affecting humans.Early diagnosis of tumor detection can be achieved by decr...Tumor detection can be carried out via the detection of proteins,such as p53,which is known to play vital role in more than 50%of all cancers affecting humans.Early diagnosis of tumor detection can be achieved by decreasing the lower detection limit of p53 bioassays.Microwave-accelerated bioassay(MAB)technique,which is based on the use of circular bioassay platforms in combination with microwave heating,is employed for the rapid and sensitive detection of p53 protein.Direct sandwich ELISA was constructed on our circular bioassay platforms based on DNA-protein binding interactions.Colorimetric and fluorescence based detection methods were used for room temperature bioassay(control bioassay;total bioassay time is 27 hours)and bioassay using microwave heating(i.e.,the MAB technique;total bioassay time is 10 minutes).In the colorimetric based detection,a very high background signal due to the non-specific binding of proteins for the bioassay carried out at room temperature and a LLOD of 0.01 ng/mL for p53 was observed using the MAB technique.The LLOD for the fluorescence-based detection using the MAB technique was found to be 0.01 ng/mL.The use of circular bioassay platforms in the MAB technique results in microwave-induced temperature gradient,where the specific protein binding interactions are significantly accelerated;thereby reducing the background signal and the lower limit of detection of p53 protein.展开更多
We present a platform technology, called Metal-Assisted and Microwave-Accelerated Decrystallization (MAMAD), which is based on the use of dispersion of gold colloids with low power microwave heating to decrystallize o...We present a platform technology, called Metal-Assisted and Microwave-Accelerated Decrystallization (MAMAD), which is based on the use of dispersion of gold colloids with low power microwave heating to decrystallize organic and biological crystals attached to surfaces. Uric acid crystals were chosen as model target crystals to be decrystallized using MAMAD technique. A two-step procedure was employed: 1) growth of uric acid crystals on a model surface (collagen films coated on to glass slides to simulate a human joint) at room temperature and 2) de-crystallization of uric acid crystals in synovial fluid (in vitro) using silver and gold colloids in conjunction with low power microwave heating. Using the MAMAD technique with gold colloids, the number of uric acid crystals was drastically reduced by 80% after 10 min, where the average size of the uric acid crystals was reduced from 125 μm to 50 μm. In control experiments and with silver colloids that aggregated from the solution, the size and number of uric crystals remained unchanged, indicating that the combined use of only metal colloids in solution and microwave heating is effective for the de-crystallization of uric acid crystals in biological media.展开更多
We report the enhancement of chemiluminescence response of horseradish peroxidase(HRP)in bioassays by plasmonic surfaces,which are comprised of(i)silver island films(SIFs)and(ii)metal thin films(silver,gold,copper,and...We report the enhancement of chemiluminescence response of horseradish peroxidase(HRP)in bioassays by plasmonic surfaces,which are comprised of(i)silver island films(SIFs)and(ii)metal thin films(silver,gold,copper,and nickel,1 nm thick)deposited onto glass slides.A model bioassay,based on the interactions of avidin-modified HRP with a monolayer of biotinylated poly(ethylene-glycol)-amine,was employed to evaluate the ability of plasmonic surfaces to enhance chemiluminescence response of HRP.Chemiluminescence response of HRP in model bioassays were increased up to~3.7-fold as compared to the control samples(i.e.glass slides without plasmonic nanoparticles),where the largest enhancement of the chemiluminescence response was observed on SIFs with high loading.These findings allowed us to demonstrate the use of SIFs(high loading)for the detection of a biologically relevant target protein(glial fibrillary acidic protein or GFAP),where the chemiluminescence response of the standard bioassay for GFAP was enhanced up to~50%as compared to bioassay on glass slides.展开更多
In this paper,we present the design of four different circular bioassay platforms,which are suitable for homogeneous microwave heating,using theoretical calculations(i.e.,COMSOLTM multiphysics software).Circular bioas...In this paper,we present the design of four different circular bioassay platforms,which are suitable for homogeneous microwave heating,using theoretical calculations(i.e.,COMSOLTM multiphysics software).Circular bioassay platforms are constructed from poly(methyl methacrylate)(PMMA)for optical transparency between 400-800 nm,has multiple sample capacity(12,16,19 and 21 wells)and modified with silver nanoparticle films(SNFs)to be used in microwave-accelerated bioassays(MABs).In addition,a small monomode microwave cavity,which can be operated with an external microwave generator(100 W),for use with the bioassay platforms in MABs is also developed.Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were:(i)temperature profiles,(ii)electric field distributions,(iii)location of the circular bioassay platforms inside the microwave cavity,and(iv)design and number of wells on the circular bioassay platforms.We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven(e.g.,900 W).Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms.The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern,where inter-well temperature was observed to be in between 23.72-24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating,which was also verified experimentally.展开更多
基金supported by Award Number 5-K25EB007565-05 from the National Institute of Biomedical Imaging and Bioengineering.
文摘In this paper,we demonstrate the application of Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC)technique to rapid and selective crystallization of a small drug compound.i.e.acetaminophen.Subsequent characterization of the crystals by optical microscopy,powder X-ray diffraction(PXRD)and Raman spectroscopy showed quantitatively selective growth of different crystal forms at various experimental conditions.Acetaminophen crystals were grown predominantly as Form I(99%)on blank glass slides at room temperature.Form II crystals with 39%purity grown on SIFs using microwave energy.
基金supported by Maryland Innovation Initiative(Phase 1)Award from Technology Development Corporation(TEDCO)support was provided by Award Number 5-K25EB007565-05 from the National Institute of Biomedical Imaging and Bioengineering.
文摘We describe the design and the use of a circular poly(methyl methacrylate)(PMMA)crystallization platform capable of processing 21 samples in Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC).The PMMA platforms were modified with silver nanoparticle films(SNFs)to generate a microwave-induced temperature gradient between the solvent and the SNFs due to the marked differences in their physical properties.Since amino acids only chemisorb on to silver on the PMMA platform,SNFs served as selective and heterogeneous nucleation sites for amino acids.Theoretical simulations for electric field and temperature distributions inside a microwave cavity equipped with a PMMA platform were carried out to determine the optimum experimental conditions,i.e.,temperature variations and placement of the PMMA platform inside a microwave cavity.In addition,the actual temperature profiles of the amino acid solutions were monitored for the duration of the crystallization experiments carried out at room temperature and during microwave heating.The crystallization of five amino acids(L-threonine,L-histidine,L-leucine,L-serine and L-valine-HCl)at room temperature(control experiment)and using MA-MAEC were followed by optical microscopy.The induction time and crystal growth rates for all amino acids were determined.Using MA-MAEC,for all amino acids the induction times were significantly reduced(up to~8-fold)and the crystal growth rates were increased(up to~50-fold)as compared to room temperature crystallization,respectively.All crystals were characterized by Raman spectroscopy and powder x-ray diffraction,which demonstrated that the crystal structures of all amino acids grown at room temperature and using MA-MAEC were similar.
基金supported by Award Number 5-K25EB007565-05 from the National Institute of Biomedical Imaging and Bioengineering.
文摘We demonstrate the design and the proof-of-concept use of a new,circular poly(methyl methacrylate)-based bioassay platform(PMMA platform),which affords for the rapid processing of 16 samples at once.The circular PMMA platform(5 cm in diameter)was coated with a silver nanoparticle film to accelerate the bioassay steps by microwave heating.A model colorimetric bioassay for biotinylated albumin(using streptavidin-labeled horse radish peroxidase)was performed on the PMMA platform coated with and without silver nanoparticles(a control experiment),and at room temperature and using microwave heating.It was shown that the simulated temperature profile of the PMMA platform during microwave heating were comparable to the real-time temperature profile during actual microwave heating of the constructed PMMA platform in a commercial microwave oven.The model colorimetric bioassay for biotinylated albumin was successfully completed in~2 min(total assay time)using microwave heating,as compared to 90 min at room temperature(total assay time),which indicates a~45-fold decrease in assay time.Our PMMA platform design afforded for significant reduction in non-specific interactions and low background signal as compared to non-silvered PMMA surfaces when employed in a microwave-accelerated bioassay carried out in a conventional microwave cavity.
基金supported(to B.Kioko)by National Institutes of Health(MBRS RISE)award number 5-R25GM058904-14.
文摘In this study,we demonstrated a unique application of our Metal-Assisted and Microwave-Accelerated Evaporative Crystallization(MA-MAEC)technique for the de-crystallization of uric acid crystals,which causes gout in humans when monosodium urate crystals accumulate in the synovial fluid found in the joints of bones.Given the shortcomings of the existing treatments for gout,we investigated whether the MA-MAEC technique can offer an alternative solution to the treatment of gout.Our technique is based on the use of metal nanoparticles(i.e.,gold colloids)with low microwave heating to accelerate the de-crystallization process.In this regard,we employed a two-step process;(i)crystallization of uric acid on glass slides,which act as a solid platform to mimic a bone,(ii)de-crystallization of uric acid crystals on glass slides with the addition of gold colloids and low power microwave heating,which act as“nano-bullets”when microwave heated in a solution.We observed that the size and number of the uric acid crystals were reduced by>60%within 10 minutes of low power microwave heating.In addition,the use of gold colloids without microwave heating(i.e.control experiment)did not result in the de-crystallization of the uric acid crystals,which proves the utility of our MA-MAEC technique in the de-crystallization of uric acid.
基金supported by National Institute of Biomedical Imaging and Bioengineering,award number 5-K25EB007565-05。
文摘Tumor detection can be carried out via the detection of proteins,such as p53,which is known to play vital role in more than 50%of all cancers affecting humans.Early diagnosis of tumor detection can be achieved by decreasing the lower detection limit of p53 bioassays.Microwave-accelerated bioassay(MAB)technique,which is based on the use of circular bioassay platforms in combination with microwave heating,is employed for the rapid and sensitive detection of p53 protein.Direct sandwich ELISA was constructed on our circular bioassay platforms based on DNA-protein binding interactions.Colorimetric and fluorescence based detection methods were used for room temperature bioassay(control bioassay;total bioassay time is 27 hours)and bioassay using microwave heating(i.e.,the MAB technique;total bioassay time is 10 minutes).In the colorimetric based detection,a very high background signal due to the non-specific binding of proteins for the bioassay carried out at room temperature and a LLOD of 0.01 ng/mL for p53 was observed using the MAB technique.The LLOD for the fluorescence-based detection using the MAB technique was found to be 0.01 ng/mL.The use of circular bioassay platforms in the MAB technique results in microwave-induced temperature gradient,where the specific protein binding interactions are significantly accelerated;thereby reducing the background signal and the lower limit of detection of p53 protein.
文摘We present a platform technology, called Metal-Assisted and Microwave-Accelerated Decrystallization (MAMAD), which is based on the use of dispersion of gold colloids with low power microwave heating to decrystallize organic and biological crystals attached to surfaces. Uric acid crystals were chosen as model target crystals to be decrystallized using MAMAD technique. A two-step procedure was employed: 1) growth of uric acid crystals on a model surface (collagen films coated on to glass slides to simulate a human joint) at room temperature and 2) de-crystallization of uric acid crystals in synovial fluid (in vitro) using silver and gold colloids in conjunction with low power microwave heating. Using the MAMAD technique with gold colloids, the number of uric acid crystals was drastically reduced by 80% after 10 min, where the average size of the uric acid crystals was reduced from 125 μm to 50 μm. In control experiments and with silver colloids that aggregated from the solution, the size and number of uric crystals remained unchanged, indicating that the combined use of only metal colloids in solution and microwave heating is effective for the de-crystallization of uric acid crystals in biological media.
基金supported by Award Number 5-K25EB007565-05 from the National Institute of Biomedical Imaging and Bioengineering.
文摘We report the enhancement of chemiluminescence response of horseradish peroxidase(HRP)in bioassays by plasmonic surfaces,which are comprised of(i)silver island films(SIFs)and(ii)metal thin films(silver,gold,copper,and nickel,1 nm thick)deposited onto glass slides.A model bioassay,based on the interactions of avidin-modified HRP with a monolayer of biotinylated poly(ethylene-glycol)-amine,was employed to evaluate the ability of plasmonic surfaces to enhance chemiluminescence response of HRP.Chemiluminescence response of HRP in model bioassays were increased up to~3.7-fold as compared to the control samples(i.e.glass slides without plasmonic nanoparticles),where the largest enhancement of the chemiluminescence response was observed on SIFs with high loading.These findings allowed us to demonstrate the use of SIFs(high loading)for the detection of a biologically relevant target protein(glial fibrillary acidic protein or GFAP),where the chemiluminescence response of the standard bioassay for GFAP was enhanced up to~50%as compared to bioassay on glass slides.
基金supported by Maryland Innovation Initiative(Phase 1)Award from Technology Development Corporation.Additional partial support was supported by Award Number 5-K25EB007565-05 from the National Institute of Biomedical Imaging and BioengineeringThe content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Biomedical Imaging and Bioengineering or the National Institutes of Health.Additional financial support was provided by the MARC U*STAR program(Grant No.5-T34GM007977-27).
文摘In this paper,we present the design of four different circular bioassay platforms,which are suitable for homogeneous microwave heating,using theoretical calculations(i.e.,COMSOLTM multiphysics software).Circular bioassay platforms are constructed from poly(methyl methacrylate)(PMMA)for optical transparency between 400-800 nm,has multiple sample capacity(12,16,19 and 21 wells)and modified with silver nanoparticle films(SNFs)to be used in microwave-accelerated bioassays(MABs).In addition,a small monomode microwave cavity,which can be operated with an external microwave generator(100 W),for use with the bioassay platforms in MABs is also developed.Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were:(i)temperature profiles,(ii)electric field distributions,(iii)location of the circular bioassay platforms inside the microwave cavity,and(iv)design and number of wells on the circular bioassay platforms.We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven(e.g.,900 W).Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms.The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern,where inter-well temperature was observed to be in between 23.72-24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating,which was also verified experimentally.
