Cholesterol oxidase (COX) is widely used enzyme for total cholesterol estimation in human serum and for the fabrication of electro-chemical biosensors. COX is also used for the bioconversion of cholesterol;for the pro...Cholesterol oxidase (COX) is widely used enzyme for total cholesterol estimation in human serum and for the fabrication of electro-chemical biosensors. COX is also used for the bioconversion of cholesterol;for the production of precursors of steroidal drugs and hormones. Enzyme activity depends decisively on defined conditions with respect to pH, temperature, ionic strength of the buffer, substrate concentration, enzyme concentration, reaction time. Standardization of these parameters is desirable to attain optimum activity of the enzyme. The present work aims to build a neural network model using five input parameters (pH, cholesterol concentration, 4-aminoantipyrine concentration, crude COX volume and horseradish peroxidase) and one output i.e., COX activity (U/ml) as a response. A feed forward back propagation neural network with Levenberg-Marquardt training algorithm was used to train the network. The network performance was assessed in terms of regression (R2), Mean Squared Error (MSE) and Mean Absolute Percentage Error (MAPE). A network topology of 5-10-1 was found to be optimum. The MSE, MAPE and R2 values of the neural model were 0.0075%, 0.12% and 0.9792% respectively. The maximum predicted activity of COX was 1.073 U/ml, which was close to the experimental value i.e., 1.1 U/ml at simulated optimum assay conditions. MSE and MAPE depicted the precision in the prediction efficiency of the developed ANN model. Higher R2 value showed a good correlation between the experimental and ANN predicted values. This proved the robustness of the ANN model to predict similar type of system (COX from other Streptomyces sp.) within the limits of the trained data set. The COX activity was enhanced by 1.71 folds after optimization of the reaction conditions.展开更多
Skin acts as protective barrier against a number of factors such as dust,opportunistic microbial and viral infections,regulates body temperature and waste discharge.Fibroblast cell population plays an important role i...Skin acts as protective barrier against a number of factors such as dust,opportunistic microbial and viral infections,regulates body temperature and waste discharge.Fibroblast cell population plays an important role in devclopment of skin architecturc.A scaffold having capability to support and enhance fibroblast growth is a viable option for wound dressing material which can shorten the time for wound to heal.In this work,Silk Fibroin(SF)and Xanthan(Xa)were blended in three ratios 80 SF:20 Xa(SFX82),60 SF:40 Xa(SFX64),and 50SF:50 Xa(SFX55)to create SF/Xa scaffold.Miscibility and other physicochemical properties of SF/Xa scaffold are functions of blending ratios and blend with the ratio 80 SF:20 Xa has the highest miscibility.Thermal properties of SF/Xa blends are a function of miscibility with SFX82 having superior thermal propertis of all fabricated scaffolds.The porosity of SF/Xa scaffolds is in the range of 67%to 50%,with pore size of 58.1 um-45.5 um,water uptake capacity of 92%-86%,and surface roughness of 49.95 nm-385 nm.SFX82 shows highest growth rate of L929 fibroblast cells indicating its superiority over other scaffolds for providing biological cues for the growth and proliferation of fibroblastic cells in natural environment.SFX82 scaffold is found to be most suitable for fibroblastic cells thereby enhancing the tissue regeneration at wound site.展开更多
Silk fibroin/xanthan scaffolds were prepared by blending silk fibroin and xanthan in the ratios 80SF:20Xa(SFX82),60SF:40Xa(SFX64),and 50SF:50Xa(SFX55)using freeze drying method.In-vitro degradation behavior of the pre...Silk fibroin/xanthan scaffolds were prepared by blending silk fibroin and xanthan in the ratios 80SF:20Xa(SFX82),60SF:40Xa(SFX64),and 50SF:50Xa(SFX55)using freeze drying method.In-vitro degradation behavior of the prepared scaffolds was studied for 37 days in phosphate buffer saline.The degradation rate was the function of silk fibroin,xanthan and^-crystallite contents in the silk fibroin/xanthan composites.SFX82 degraded extremely slowly whereas SFX55 showed faster degradation rate.Hydrophilic xanthan was the main contributor of weight loss.SFX82 and SFX64 exhibited surface degradation whereas SFX55 showed bulk degradation which indicated that higher silk fibroin ratios favor surface degradation.Due to bulk degradation,SFX55 showed maximum surface roughness among the composite scaffolds.The FTIR spectrum revealed total loss of xanthan from the composites after degradation.The broad and low-intensity peaks in the FTIR spectrum of composite scaffolds con finned reduction in 0-sheet crystallite content during degradation.XRD analysis also confirmed reduction in 0-sheet crystals and revealed that degraded composite scaffold had predominantly amorphous structure.The degraded scaffold showed higher porous structure than the non-degraded scaffold.The in vitro degradability testing gives a good approximation of degradation of scaffold in vivo and helps in designing a robust biopolymeric composite scaffold for tissue engineering.展开更多
文摘Cholesterol oxidase (COX) is widely used enzyme for total cholesterol estimation in human serum and for the fabrication of electro-chemical biosensors. COX is also used for the bioconversion of cholesterol;for the production of precursors of steroidal drugs and hormones. Enzyme activity depends decisively on defined conditions with respect to pH, temperature, ionic strength of the buffer, substrate concentration, enzyme concentration, reaction time. Standardization of these parameters is desirable to attain optimum activity of the enzyme. The present work aims to build a neural network model using five input parameters (pH, cholesterol concentration, 4-aminoantipyrine concentration, crude COX volume and horseradish peroxidase) and one output i.e., COX activity (U/ml) as a response. A feed forward back propagation neural network with Levenberg-Marquardt training algorithm was used to train the network. The network performance was assessed in terms of regression (R2), Mean Squared Error (MSE) and Mean Absolute Percentage Error (MAPE). A network topology of 5-10-1 was found to be optimum. The MSE, MAPE and R2 values of the neural model were 0.0075%, 0.12% and 0.9792% respectively. The maximum predicted activity of COX was 1.073 U/ml, which was close to the experimental value i.e., 1.1 U/ml at simulated optimum assay conditions. MSE and MAPE depicted the precision in the prediction efficiency of the developed ANN model. Higher R2 value showed a good correlation between the experimental and ANN predicted values. This proved the robustness of the ANN model to predict similar type of system (COX from other Streptomyces sp.) within the limits of the trained data set. The COX activity was enhanced by 1.71 folds after optimization of the reaction conditions.
文摘Skin acts as protective barrier against a number of factors such as dust,opportunistic microbial and viral infections,regulates body temperature and waste discharge.Fibroblast cell population plays an important role in devclopment of skin architecturc.A scaffold having capability to support and enhance fibroblast growth is a viable option for wound dressing material which can shorten the time for wound to heal.In this work,Silk Fibroin(SF)and Xanthan(Xa)were blended in three ratios 80 SF:20 Xa(SFX82),60 SF:40 Xa(SFX64),and 50SF:50 Xa(SFX55)to create SF/Xa scaffold.Miscibility and other physicochemical properties of SF/Xa scaffold are functions of blending ratios and blend with the ratio 80 SF:20 Xa has the highest miscibility.Thermal properties of SF/Xa blends are a function of miscibility with SFX82 having superior thermal propertis of all fabricated scaffolds.The porosity of SF/Xa scaffolds is in the range of 67%to 50%,with pore size of 58.1 um-45.5 um,water uptake capacity of 92%-86%,and surface roughness of 49.95 nm-385 nm.SFX82 shows highest growth rate of L929 fibroblast cells indicating its superiority over other scaffolds for providing biological cues for the growth and proliferation of fibroblastic cells in natural environment.SFX82 scaffold is found to be most suitable for fibroblastic cells thereby enhancing the tissue regeneration at wound site.
文摘Silk fibroin/xanthan scaffolds were prepared by blending silk fibroin and xanthan in the ratios 80SF:20Xa(SFX82),60SF:40Xa(SFX64),and 50SF:50Xa(SFX55)using freeze drying method.In-vitro degradation behavior of the prepared scaffolds was studied for 37 days in phosphate buffer saline.The degradation rate was the function of silk fibroin,xanthan and^-crystallite contents in the silk fibroin/xanthan composites.SFX82 degraded extremely slowly whereas SFX55 showed faster degradation rate.Hydrophilic xanthan was the main contributor of weight loss.SFX82 and SFX64 exhibited surface degradation whereas SFX55 showed bulk degradation which indicated that higher silk fibroin ratios favor surface degradation.Due to bulk degradation,SFX55 showed maximum surface roughness among the composite scaffolds.The FTIR spectrum revealed total loss of xanthan from the composites after degradation.The broad and low-intensity peaks in the FTIR spectrum of composite scaffolds con finned reduction in 0-sheet crystallite content during degradation.XRD analysis also confirmed reduction in 0-sheet crystals and revealed that degraded composite scaffold had predominantly amorphous structure.The degraded scaffold showed higher porous structure than the non-degraded scaffold.The in vitro degradability testing gives a good approximation of degradation of scaffold in vivo and helps in designing a robust biopolymeric composite scaffold for tissue engineering.
