Efficient strategies to promote microvascularization in vascular tissue engineering,a central priority in regenerative medicine,are still scarce;nano-and micro-sized aggregates and spheres or beads harboring primitive...Efficient strategies to promote microvascularization in vascular tissue engineering,a central priority in regenerative medicine,are still scarce;nano-and micro-sized aggregates and spheres or beads harboring primitive microvascular beds are promising methods in vascular tissue engineering.Capillaries are the smallest type and in numerous blood vessels,which are distributed densely in cardiovascular system.To mimic this microvascular network,specific cell components and proangiogenic factors are required.Herein,advanced biofabrication methods in microvascular engineering,including extrusion-based and droplet-based bioprinting,Kenzan,and biogripper approaches,are deliberated with emphasis on the newest works in prevascular nano-and micro-sized aggregates and microspheres/microbeads.展开更多
Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are...Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are limited to drugs with low molecular weight.Hence,new emerging technology allowing high molecular weight drug delivery across the skin—known as‘microneedles’—has been developed,which creates microchannels that facilitate drug delivery.In this report,drug-loaded degradable conic microneedles are modeled to characterize the degradation rate and drug release profile.Since a lot of data are available for polylactic acid-co-glycolic acid(PLGA)degradation in the literature,PLGA of various molecular weights-as a biodegradable polymer in the polyester family-is used for modeling and verification of the drug delivery in themicroneedles.The main reaction occurring during polyester degradation is hydrolysis of steric bonds,leading to molecular weight reduction.The acid produced in the degradation has a catalytic effect on the reaction.Changes in water,acid and steric bond concentrations over time and for different radii of microneedles are investigated.To solve the partial and ordinary differential equations simultaneously,finite difference and Runge–Kutta methods are employed,respectively,with the aid of MATLAB.Correlation of the polymer degradation rate with its molecular weight and molecular weight changes versus time are illustrated.Also,drug diffusivity is related to matrix molecular weight.The molecular weight reduction and accumulative drug release within the system are predicted.In order to validate and assess the proposed model,data series of the hydrolytic degradation of aspirin(180.16 Da)-and albumin(66,000 Da)-loaded PLGA(1:1 molar ratio)are used for comparison.The proposed model is in good agreement with experimental data from the literature.Considering diffusion as themain phenomena and autocatalytic effects in the reaction,the drug release profile is predicted.Based on our results for a microneedle containing drug,we are able to estimate drug release rates before fabrication.展开更多
A one-pot synthesis method was conceptualized and implemented to develop green carbon-based nanocomposites working as biosensors.Porphyrin was synthesized to adorn the surface of nanocomposites making them highly sens...A one-pot synthesis method was conceptualized and implemented to develop green carbon-based nanocomposites working as biosensors.Porphyrin was synthesized to adorn the surface of nanocomposites making them highly sensitive for giving rise to π-π interactions between the genetic materials,proteins and porphyrin rings.The hydrogen bond formed between the proteins(analytes)and the nitrogen in the porphyrin structure as well as the surface hydroxyl groups was equally probable.In this context,different forms of porphyrins were incorporated to explore the interrelationship between the surface morphology and the ability of detection of genetic material and/or proteins by the aid of the synthesized structures.This phenomenon was conceptualized to optimize the interactions between the biomolecules and the substrate by reaching significant biosensor application in the presence of Anti-cas9 protein and sgRNA(concentration changed between 10 and 500 n mol/L).Almost full quenching of fluorescence emission was observed after addition of 300 n mol/L of Anti-cas9 protein and 250 n mol/L of sgRNA.Surprisingly,CoNi_(2)S_(4)provided 12%-29%cytotoxicity in both HEK-293 and PC12 cell lines.展开更多
文摘Efficient strategies to promote microvascularization in vascular tissue engineering,a central priority in regenerative medicine,are still scarce;nano-and micro-sized aggregates and spheres or beads harboring primitive microvascular beds are promising methods in vascular tissue engineering.Capillaries are the smallest type and in numerous blood vessels,which are distributed densely in cardiovascular system.To mimic this microvascular network,specific cell components and proangiogenic factors are required.Herein,advanced biofabrication methods in microvascular engineering,including extrusion-based and droplet-based bioprinting,Kenzan,and biogripper approaches,are deliberated with emphasis on the newest works in prevascular nano-and micro-sized aggregates and microspheres/microbeads.
文摘Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are limited to drugs with low molecular weight.Hence,new emerging technology allowing high molecular weight drug delivery across the skin—known as‘microneedles’—has been developed,which creates microchannels that facilitate drug delivery.In this report,drug-loaded degradable conic microneedles are modeled to characterize the degradation rate and drug release profile.Since a lot of data are available for polylactic acid-co-glycolic acid(PLGA)degradation in the literature,PLGA of various molecular weights-as a biodegradable polymer in the polyester family-is used for modeling and verification of the drug delivery in themicroneedles.The main reaction occurring during polyester degradation is hydrolysis of steric bonds,leading to molecular weight reduction.The acid produced in the degradation has a catalytic effect on the reaction.Changes in water,acid and steric bond concentrations over time and for different radii of microneedles are investigated.To solve the partial and ordinary differential equations simultaneously,finite difference and Runge–Kutta methods are employed,respectively,with the aid of MATLAB.Correlation of the polymer degradation rate with its molecular weight and molecular weight changes versus time are illustrated.Also,drug diffusivity is related to matrix molecular weight.The molecular weight reduction and accumulative drug release within the system are predicted.In order to validate and assess the proposed model,data series of the hydrolytic degradation of aspirin(180.16 Da)-and albumin(66,000 Da)-loaded PLGA(1:1 molar ratio)are used for comparison.The proposed model is in good agreement with experimental data from the literature.Considering diffusion as themain phenomena and autocatalytic effects in the reaction,the drug release profile is predicted.Based on our results for a microneedle containing drug,we are able to estimate drug release rates before fabrication.
文摘A one-pot synthesis method was conceptualized and implemented to develop green carbon-based nanocomposites working as biosensors.Porphyrin was synthesized to adorn the surface of nanocomposites making them highly sensitive for giving rise to π-π interactions between the genetic materials,proteins and porphyrin rings.The hydrogen bond formed between the proteins(analytes)and the nitrogen in the porphyrin structure as well as the surface hydroxyl groups was equally probable.In this context,different forms of porphyrins were incorporated to explore the interrelationship between the surface morphology and the ability of detection of genetic material and/or proteins by the aid of the synthesized structures.This phenomenon was conceptualized to optimize the interactions between the biomolecules and the substrate by reaching significant biosensor application in the presence of Anti-cas9 protein and sgRNA(concentration changed between 10 and 500 n mol/L).Almost full quenching of fluorescence emission was observed after addition of 300 n mol/L of Anti-cas9 protein and 250 n mol/L of sgRNA.Surprisingly,CoNi_(2)S_(4)provided 12%-29%cytotoxicity in both HEK-293 and PC12 cell lines.
