Calix[n]arenes was utilized to detect PABA,the primary sunscreen component.This study investigates the interaction of calix[4]arene(C4),calix[6]arene(C6),and PABA using the Langmuir method and first-principle density ...Calix[n]arenes was utilized to detect PABA,the primary sunscreen component.This study investigates the interaction of calix[4]arene(C4),calix[6]arene(C6),and PABA using the Langmuir method and first-principle density functional theory(DFT).Using the Langmuir-Schaefer(LS)technique,an ultrathin film composed of calix[n]arenes and their complexes with PABA was deposited on various substrates.Based on the Langmuir study,the PABA molecule was bonded to the lower rims of both C4 and C6 with the host-guest ratio of 1:1.All of the LS films formed were then characterized by ultravioletvisible spectroscopy(UV-Vis),Fourier-transform infrared spectroscopy(FTIR)and carbon,hydrogen,nitrogen,sulfur elemental analyzer(CHNS).The band gap reduction obtained in the DFT study denotes the charge transfer interaction with promising reactivity between the calix[n]arenes and PABA.The sensing of PABA by C4 and C6 is successful based on the formation of bonding between them due to the hosts’effective trapping capacity.The outcomes of this study could be applied to drug delivery systems for future pharmaceutical and medical applications.展开更多
基于过氧化氢酶(HRP)催化和硼酸特异性识别,成功制备了一种多壁碳纳米管-HRP-聚氨基苯硼酸(MWCNTs-HRP-PABA)复合膜并用于过氧化氢生物传感器.紫外-可见和红外光谱表明MWCNTs-HRPPABA复合物具有良好的生物相容性并保持了HRP的生物活性....基于过氧化氢酶(HRP)催化和硼酸特异性识别,成功制备了一种多壁碳纳米管-HRP-聚氨基苯硼酸(MWCNTs-HRP-PABA)复合膜并用于过氧化氢生物传感器.紫外-可见和红外光谱表明MWCNTs-HRPPABA复合物具有良好的生物相容性并保持了HRP的生物活性.电化学阻抗谱(EIS)和扫描电化学显微镜(SEM)表明,在HRP酶的催化下,聚氨基苯硼酸成功聚合.在0.1 M PBS溶液中,PABA具有一对可逆的氧化还原峰,表明了HRP酶的活性中心与电极之间的直接电化学.该生物传感器性能良好,过氧化氢的浓度在1.21 m M至20 M之间具有良好的线性关系,其相关系数为0.9973,检测下限为5.0 M(S/N=3).因此,这种基于HRP催化和硼酸特异性识别的方法为设计独特的生物传感器提供了一个良好的平台.展开更多
Para-amino benzoic acid(PABA),a folic acid related metabolite,was first introduced to fabricate micro-grooves and improve hydrophilicity over surfaces of carbon fibers(CFs).Then,engineered CFs/poly(lactic acid)-poly(e...Para-amino benzoic acid(PABA),a folic acid related metabolite,was first introduced to fabricate micro-grooves and improve hydrophilicity over surfaces of carbon fibers(CFs).Then,engineered CFs/poly(lactic acid)-poly(ethylene glycol)(PLA-PEG) biocomposites were fabricated by a solvent casting/particulate leaching method.We found that introducing small hydrophobic PABA molecules and fabricating patterned structures would lead to benign integrated interfaces between CFs and the PLA-PEG matrix.Specifically,the compressive strength of CFs/PLA-PEG was improved from 3.98 to 5.48 MPa.In addition,the CFs/PLA-PEG biocomposites significantly accelerated the adhesion and proliferation of pre-osteoblasts with minimized cytotoxidty.By comparing the cyto-compatibility of L929 and MC_3T_3 cells cultured on different modified PLA-PEG composites,it could be concluded that PABA-CFs not only overcame the limitation of poor strength of PLA-PEG,but also improved the cell growth.These results indicate that the PABA-CFs reinforced PLA-PEG biocomposites could be a potential alternative for tissue engineering scaffolds.展开更多
Five different bifidobacterial cultures were screened to investigate if their de novo folate production ability could be predicated based on their folate biosynthetic gene content.As previously developed folate free m...Five different bifidobacterial cultures were screened to investigate if their de novo folate production ability could be predicated based on their folate biosynthetic gene content.As previously developed folate free media could not adequately support the growth of these five strains,even with added folate,an alternative medium(YNB+)was developed.Consistent with its genome prediction,Bifidobacterium animalis subsp.lactis strain Bb-12 required folate for its growth even in the presence of p-aminobenzoic acid(PABA).Although B.longum DJO10A and B.breve ATCC 15701 lack an alkaline phosphatase gene for the formation of one pathway intermediate(DHPPP),both were found to be able to grow independent from folate and PABA suggesting that lack of these genes in genome annotations cannot be used to predict folate dependency in bifidobacteria.Similarly,having all required genes cannot always predict folate production,as B.longum subsp.infantis RECb4 contained a full set of pathway genes,but required folate or PABA for growth.While many bifidobacteria can produce folate,this also cannot be used to predicate their ability to supply folate as some can act as scavengers when folate is readily available in the environment,such as B.breve ATCC 15701 in this study.As bifidobacterial cultures are sometimes considered for use in foods based on their folate production abilities,it is important to consider whether they function as folate scavengers or suppliers when growing in folate containing media.展开更多
基金Funded by the Sultan Idris Education University(UPSI)(No.2020-0256-103-02(FRGS/1/2020/STG07/UPSI/02/2))provided by the Ministry of Higher Education,Malaysia。
文摘Calix[n]arenes was utilized to detect PABA,the primary sunscreen component.This study investigates the interaction of calix[4]arene(C4),calix[6]arene(C6),and PABA using the Langmuir method and first-principle density functional theory(DFT).Using the Langmuir-Schaefer(LS)technique,an ultrathin film composed of calix[n]arenes and their complexes with PABA was deposited on various substrates.Based on the Langmuir study,the PABA molecule was bonded to the lower rims of both C4 and C6 with the host-guest ratio of 1:1.All of the LS films formed were then characterized by ultravioletvisible spectroscopy(UV-Vis),Fourier-transform infrared spectroscopy(FTIR)and carbon,hydrogen,nitrogen,sulfur elemental analyzer(CHNS).The band gap reduction obtained in the DFT study denotes the charge transfer interaction with promising reactivity between the calix[n]arenes and PABA.The sensing of PABA by C4 and C6 is successful based on the formation of bonding between them due to the hosts’effective trapping capacity.The outcomes of this study could be applied to drug delivery systems for future pharmaceutical and medical applications.
文摘基于过氧化氢酶(HRP)催化和硼酸特异性识别,成功制备了一种多壁碳纳米管-HRP-聚氨基苯硼酸(MWCNTs-HRP-PABA)复合膜并用于过氧化氢生物传感器.紫外-可见和红外光谱表明MWCNTs-HRPPABA复合物具有良好的生物相容性并保持了HRP的生物活性.电化学阻抗谱(EIS)和扫描电化学显微镜(SEM)表明,在HRP酶的催化下,聚氨基苯硼酸成功聚合.在0.1 M PBS溶液中,PABA具有一对可逆的氧化还原峰,表明了HRP酶的活性中心与电极之间的直接电化学.该生物传感器性能良好,过氧化氢的浓度在1.21 m M至20 M之间具有良好的线性关系,其相关系数为0.9973,检测下限为5.0 M(S/N=3).因此,这种基于HRP催化和硼酸特异性识别的方法为设计独特的生物传感器提供了一个良好的平台.
基金supported by the National Key Research and Development Project(2016YFB0303201)the Research and Innovation Project of Shanghai Municipal Education Commission(14zz069)Donghua University Graduates'Innovation Funding Projects(EG2015006)
文摘Para-amino benzoic acid(PABA),a folic acid related metabolite,was first introduced to fabricate micro-grooves and improve hydrophilicity over surfaces of carbon fibers(CFs).Then,engineered CFs/poly(lactic acid)-poly(ethylene glycol)(PLA-PEG) biocomposites were fabricated by a solvent casting/particulate leaching method.We found that introducing small hydrophobic PABA molecules and fabricating patterned structures would lead to benign integrated interfaces between CFs and the PLA-PEG matrix.Specifically,the compressive strength of CFs/PLA-PEG was improved from 3.98 to 5.48 MPa.In addition,the CFs/PLA-PEG biocomposites significantly accelerated the adhesion and proliferation of pre-osteoblasts with minimized cytotoxidty.By comparing the cyto-compatibility of L929 and MC_3T_3 cells cultured on different modified PLA-PEG composites,it could be concluded that PABA-CFs not only overcame the limitation of poor strength of PLA-PEG,but also improved the cell growth.These results indicate that the PABA-CFs reinforced PLA-PEG biocomposites could be a potential alternative for tissue engineering scaffolds.
文摘Five different bifidobacterial cultures were screened to investigate if their de novo folate production ability could be predicated based on their folate biosynthetic gene content.As previously developed folate free media could not adequately support the growth of these five strains,even with added folate,an alternative medium(YNB+)was developed.Consistent with its genome prediction,Bifidobacterium animalis subsp.lactis strain Bb-12 required folate for its growth even in the presence of p-aminobenzoic acid(PABA).Although B.longum DJO10A and B.breve ATCC 15701 lack an alkaline phosphatase gene for the formation of one pathway intermediate(DHPPP),both were found to be able to grow independent from folate and PABA suggesting that lack of these genes in genome annotations cannot be used to predict folate dependency in bifidobacteria.Similarly,having all required genes cannot always predict folate production,as B.longum subsp.infantis RECb4 contained a full set of pathway genes,but required folate or PABA for growth.While many bifidobacteria can produce folate,this also cannot be used to predicate their ability to supply folate as some can act as scavengers when folate is readily available in the environment,such as B.breve ATCC 15701 in this study.As bifidobacterial cultures are sometimes considered for use in foods based on their folate production abilities,it is important to consider whether they function as folate scavengers or suppliers when growing in folate containing media.
