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
The use of indium tin oxide(ITO)and focused monomode microwave heating for the ultra-rapid crystallization of L-alanine(a model amino acid)is reported.Commercially available ITO dots(<5 mm)attached to blank poly(me...The use of indium tin oxide(ITO)and focused monomode microwave heating for the ultra-rapid crystallization of L-alanine(a model amino acid)is reported.Commercially available ITO dots(<5 mm)attached to blank poly(methyl)methacrylate(PMMA,5 cm in diameter with 21-well silicon isolators:referred to as the iCrystal plates)were found to withstand prolonged microwave heating during crystallization experiments.Crystallization of L-alanine was performed at room temperature(a control experiment),with the use of two microwave sources:a 2.45 GHz conventional microwave(900 W,power level 1,a control experiment)and 8 GHz(20 W)solid state,monomode microwave source with an applicator tip that focuses the microwave field to a 5-mm cavity.Initial appearance of L-alanine crystals and on iCrystal plates with ITO dots took 47±2.9 min,12±7.6 min and 1.5±0.5 min at room temperature,using a conventional microwave and focused monomode microwave heating,respectively.Complete evaporation of the solvent using the focused microwaves was achieved in 3.2±0.5 min,which is~52-fold and~172-fold faster than that observed at room temperature and using conventional microwave heating,respectively.The size and number of L-alanine crystals was dependent on the type of the 21-well iCrystal plates and the microwave heating method:33 crystals of 585±137μm in size at room temperature>37 crystals of 542±100μm in size with conventional microwave heating>331 crystals of 311±190μm in size with focused monomode microwave.FTIR,optical microscopy and powder X-ray diffraction analysis showed that the chemical composition and crystallinity of the L-alanine crystals did not change when exposed to microwave heating and ITO surfaces.In addition,theoretical simulations for the binding of L-alanine molecules to ITO and other metals showed the predicted nature of hydrogen bonds formed between L-alanine and these surfaces.展开更多
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.
文摘The use of indium tin oxide(ITO)and focused monomode microwave heating for the ultra-rapid crystallization of L-alanine(a model amino acid)is reported.Commercially available ITO dots(<5 mm)attached to blank poly(methyl)methacrylate(PMMA,5 cm in diameter with 21-well silicon isolators:referred to as the iCrystal plates)were found to withstand prolonged microwave heating during crystallization experiments.Crystallization of L-alanine was performed at room temperature(a control experiment),with the use of two microwave sources:a 2.45 GHz conventional microwave(900 W,power level 1,a control experiment)and 8 GHz(20 W)solid state,monomode microwave source with an applicator tip that focuses the microwave field to a 5-mm cavity.Initial appearance of L-alanine crystals and on iCrystal plates with ITO dots took 47±2.9 min,12±7.6 min and 1.5±0.5 min at room temperature,using a conventional microwave and focused monomode microwave heating,respectively.Complete evaporation of the solvent using the focused microwaves was achieved in 3.2±0.5 min,which is~52-fold and~172-fold faster than that observed at room temperature and using conventional microwave heating,respectively.The size and number of L-alanine crystals was dependent on the type of the 21-well iCrystal plates and the microwave heating method:33 crystals of 585±137μm in size at room temperature>37 crystals of 542±100μm in size with conventional microwave heating>331 crystals of 311±190μm in size with focused monomode microwave.FTIR,optical microscopy and powder X-ray diffraction analysis showed that the chemical composition and crystallinity of the L-alanine crystals did not change when exposed to microwave heating and ITO surfaces.In addition,theoretical simulations for the binding of L-alanine molecules to ITO and other metals showed the predicted nature of hydrogen bonds formed between L-alanine and these surfaces.
