The motive of this work was to provide an inexpensive potential wound dressing using chitosan lactate (LCH) which was synthesized by the grafting lactic acid onto the amino groups in chitosan (CH) without a catalyst. ...The motive of this work was to provide an inexpensive potential wound dressing using chitosan lactate (LCH) which was synthesized by the grafting lactic acid onto the amino groups in chitosan (CH) without a catalyst. The XRD and 13CNMR results demonstrated that the grafting by lactic acid took place at C2 site in CH, leading to the destruction of the regularity of the packing in the original CH chains and formation of the amorphous CH salts. The unique device was developed in our experiments which could yield an approximately vertical thermal gradient, forming the uniformly vertical pores in LCH sponges. TEM images revealed that both TBA and LCH concentration affected the micro-structure of the sponges, although they worked via different mechanisms. In the water suction experiments, the capillary coefficient Ks was introduced to evaluate the structure-function relationship. The positive or negative influence of LCH, TBA and porosity on Ks clearly stood out when their relationships were plotted graphically. The in vitro biocompatibility of LCH sponges was evaluated. The results obtained indicated that LCH sponges exhibited bio-safety at lower concentration (25%) during short time (1 day). However, highly concentrated extraction showed a serious toxic effect on both HSF and HaCaT cells. The release kinetics for hydrophilic and hydrophobic drugs with different formulation sponges was determined in in vitro release experiments. The contribution of the drug diffusion, matrix erosion and microstructure of porous materials must be taken into account on the release mechanism. The method and the structure described in present paper provided a starting point for the design and fabrication of a family of chitosan derivatives based porous materials with potentially broad展开更多
Chitosan oligosaccharides(COS)are the hydrolyzed product of chitosan and have multifunctional health benefits.The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their pr...Chitosan oligosaccharides(COS)are the hydrolyzed product of chitosan and have multifunctional health benefits.The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their productivity and health and that of their litters.Gilts were randomly assigned to either a treatment(n=30)or control group(n=30).The treatment gilts were fed a standard dry sow ration supplemented with COS at 0.12 and 0.24 g/gilt per d during gestation and lactation,respectively,and the control group was fed the standard dry sow ration only.The body weight,reproductive performance,milk production and litter size for each gilt and body weight of corresponding litters were recorded.The serum immunoglobulins(IgA,IgG,IgM)and secretory immunoglobulin A(sIgA)concentrations of gilts and piglets and fecal sIgA concertation of gilts were measured by Enzyme-linked immunosorbent assay(ELISA).Our study showed that maternal COS supplementation 1)significantly increased gilt body weight in late pregnancy(P<0.05),2)significantly increased milk production of gilts at different stages(d 1,3,7 and19)of lactation(P<0.05),3)significantly increased body weight gain of piglets at weaning(P<0.05),4)significantly increased the serum concentrations of IgM and sIgA in piglets,and slgA in fecal sample of gilts(P<0.05),and 5)tended to increase the pregnancy success rate(P>0.05)in the treatment group compared to the control group.These results suggest that maternal COS intervention in gilts can improve gilt milk production,piglet pre-weaning growth and immunity parameters in both gilts and piglets.展开更多
文摘The motive of this work was to provide an inexpensive potential wound dressing using chitosan lactate (LCH) which was synthesized by the grafting lactic acid onto the amino groups in chitosan (CH) without a catalyst. The XRD and 13CNMR results demonstrated that the grafting by lactic acid took place at C2 site in CH, leading to the destruction of the regularity of the packing in the original CH chains and formation of the amorphous CH salts. The unique device was developed in our experiments which could yield an approximately vertical thermal gradient, forming the uniformly vertical pores in LCH sponges. TEM images revealed that both TBA and LCH concentration affected the micro-structure of the sponges, although they worked via different mechanisms. In the water suction experiments, the capillary coefficient Ks was introduced to evaluate the structure-function relationship. The positive or negative influence of LCH, TBA and porosity on Ks clearly stood out when their relationships were plotted graphically. The in vitro biocompatibility of LCH sponges was evaluated. The results obtained indicated that LCH sponges exhibited bio-safety at lower concentration (25%) during short time (1 day). However, highly concentrated extraction showed a serious toxic effect on both HSF and HaCaT cells. The release kinetics for hydrophilic and hydrophobic drugs with different formulation sponges was determined in in vitro release experiments. The contribution of the drug diffusion, matrix erosion and microstructure of porous materials must be taken into account on the release mechanism. The method and the structure described in present paper provided a starting point for the design and fabrication of a family of chitosan derivatives based porous materials with potentially broad
文摘Chitosan oligosaccharides(COS)are the hydrolyzed product of chitosan and have multifunctional health benefits.The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their productivity and health and that of their litters.Gilts were randomly assigned to either a treatment(n=30)or control group(n=30).The treatment gilts were fed a standard dry sow ration supplemented with COS at 0.12 and 0.24 g/gilt per d during gestation and lactation,respectively,and the control group was fed the standard dry sow ration only.The body weight,reproductive performance,milk production and litter size for each gilt and body weight of corresponding litters were recorded.The serum immunoglobulins(IgA,IgG,IgM)and secretory immunoglobulin A(sIgA)concentrations of gilts and piglets and fecal sIgA concertation of gilts were measured by Enzyme-linked immunosorbent assay(ELISA).Our study showed that maternal COS supplementation 1)significantly increased gilt body weight in late pregnancy(P<0.05),2)significantly increased milk production of gilts at different stages(d 1,3,7 and19)of lactation(P<0.05),3)significantly increased body weight gain of piglets at weaning(P<0.05),4)significantly increased the serum concentrations of IgM and sIgA in piglets,and slgA in fecal sample of gilts(P<0.05),and 5)tended to increase the pregnancy success rate(P>0.05)in the treatment group compared to the control group.These results suggest that maternal COS intervention in gilts can improve gilt milk production,piglet pre-weaning growth and immunity parameters in both gilts and piglets.
