The multilayer of polyethylenimine (PEI) and carrageenan (k, i, l) formed by layer-by-layer assembly was investigated for its antibacterial activity against Enterobacter cloaceae, Staphylococcus aureus and Enterococcu...The multilayer of polyethylenimine (PEI) and carrageenan (k, i, l) formed by layer-by-layer assembly was investigated for its antibacterial activity against Enterobacter cloaceae, Staphylococcus aureus and Enterococcus faecalis 29505 for potential use as coating on biomaterial surface. All the multilayers exhibited growth inhibition. PEI/Iota carrageenan multilayer was effective in inhibiting the growth of the E. cloaceae, S. aureus and E. faecalis while PEI/Lambda carrageenan was effective in inhibiting the growth of E. cloaceae. Results of the paper strip test for combined action of carrageenan and PEI showed synergism with regards to bacterial growth inhibition. The multilayers had also contact-killing effect with the test organisms. The multilayer was also characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and biomolecular interaction analysis.展开更多
Mild hydrochloric acid hydrolysis of i-carrageenan from Eucheuma spinosum yielded two oligosaccharides of sulfated tetrasaccharide structure. These were characterized by Fourier Transform Infrared Spectroscopy (FT-IR)...Mild hydrochloric acid hydrolysis of i-carrageenan from Eucheuma spinosum yielded two oligosaccharides of sulfated tetrasaccharide structure. These were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) and Electrospray Ionization Mass Spectrometry (ESIMS). Both oligosaccharides have structure of b-D-galactopyranose(Galp)4S-(1→4)-α-D-AnGalp2S-(1→3)-b-D-galactopyranose Galp)4S-(1→4)-α-D-AnGalp2S-(1→3). Application of the resulting oligosaccharides on protein delivery system in terms of encapsulation efficiency was performed.展开更多
Manufactured nanomaterials are expected to enter the environment due to the increasing number of productions which results in anthropological discharges coming from different effluents and seepages.This event poses po...Manufactured nanomaterials are expected to enter the environment due to the increasing number of productions which results in anthropological discharges coming from different effluents and seepages.This event poses potential threat to the environment especially in the aquatic systems.TiO2(titanium dioxide)and AgNPs(silver nanoparticles)have significant potential in antibacterial and antiparasitic applications,but despite their significant potential,the toxicity of metal oxide nanoparticles such as TiO2 and AgNPs restricts their use especially in humans due to their toxicity.In this study,the behavior and toxicity of TiO2 and AgNPs were investigated in aquatic system using Artemia franciscana nauplii and Daphnia magna.Nauplii and Daphnia were exposed to TiO2 and AgNP dispersions at different concentrations.The mortality rates of the nauplii and daphnia were monitored at 6,24,and 48 h after its exposure.Saltwater results showed that AgNP is highly toxic to the test organisms while TiO2 was non-toxic after 48 h of exposure.For freshwater,100%mortality rate on neonates was obtained from the AgNPs dispersion during the first 6 h of exposure while the mortality rate in TiO2 dispersion was 85%at 100 ppm after 48 h of exposure.展开更多
文摘The multilayer of polyethylenimine (PEI) and carrageenan (k, i, l) formed by layer-by-layer assembly was investigated for its antibacterial activity against Enterobacter cloaceae, Staphylococcus aureus and Enterococcus faecalis 29505 for potential use as coating on biomaterial surface. All the multilayers exhibited growth inhibition. PEI/Iota carrageenan multilayer was effective in inhibiting the growth of the E. cloaceae, S. aureus and E. faecalis while PEI/Lambda carrageenan was effective in inhibiting the growth of E. cloaceae. Results of the paper strip test for combined action of carrageenan and PEI showed synergism with regards to bacterial growth inhibition. The multilayers had also contact-killing effect with the test organisms. The multilayer was also characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and biomolecular interaction analysis.
文摘Mild hydrochloric acid hydrolysis of i-carrageenan from Eucheuma spinosum yielded two oligosaccharides of sulfated tetrasaccharide structure. These were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) and Electrospray Ionization Mass Spectrometry (ESIMS). Both oligosaccharides have structure of b-D-galactopyranose(Galp)4S-(1→4)-α-D-AnGalp2S-(1→3)-b-D-galactopyranose Galp)4S-(1→4)-α-D-AnGalp2S-(1→3). Application of the resulting oligosaccharides on protein delivery system in terms of encapsulation efficiency was performed.
文摘Manufactured nanomaterials are expected to enter the environment due to the increasing number of productions which results in anthropological discharges coming from different effluents and seepages.This event poses potential threat to the environment especially in the aquatic systems.TiO2(titanium dioxide)and AgNPs(silver nanoparticles)have significant potential in antibacterial and antiparasitic applications,but despite their significant potential,the toxicity of metal oxide nanoparticles such as TiO2 and AgNPs restricts their use especially in humans due to their toxicity.In this study,the behavior and toxicity of TiO2 and AgNPs were investigated in aquatic system using Artemia franciscana nauplii and Daphnia magna.Nauplii and Daphnia were exposed to TiO2 and AgNP dispersions at different concentrations.The mortality rates of the nauplii and daphnia were monitored at 6,24,and 48 h after its exposure.Saltwater results showed that AgNP is highly toxic to the test organisms while TiO2 was non-toxic after 48 h of exposure.For freshwater,100%mortality rate on neonates was obtained from the AgNPs dispersion during the first 6 h of exposure while the mortality rate in TiO2 dispersion was 85%at 100 ppm after 48 h of exposure.
