1.Preparation of niclosamide ethanolamine nano-suspension and its molluscicidal effect
Liu JIANG ; Shufeng LI ; Xinsong LI ; Jianrong DAI ; Yinchang ZHU
Chinese Journal of Schistosomiasis Control 1989;0(02):-
Objective To prepare a novel nano-suspension of niclosamide ethanolamine and evaluate its molluscicidal effect. Methods Niclosamide ethanolamine and stabilizing agent—polyvinylpyrrolidone (PVP) were dissolved in dimethyl sulfoxide. After the solution was added into water under fast stirring, niclosamide ethanolamine was quickly precipitated to form nanoparticles and nano-suspension was obtained. The weight ratio of PVP to niclosamide ethanolamine, concentration, temperature, stirring speed on the size and distribution of the nanoparticles were investigated. The molluscicidal effect of niclosamide ethanolamine nano-suspension was measured by immersion and spray methods in the laboratory and field. Results When the weight ratio of PVP to niclosamide ethanolamine was from 1∶2 to 1∶3, the nanoparticles of the niclosamide ethanolamine had diameters about 100 nm and the nano-suspension was stable without agglomerating for more than 1 month; as the speed of the stirring increased, the nanoparticles prepared became smaller and more stable. LC50 of the nano-suspension was 0.0544 mg/L but the LC50 of wettable powder of niclosamide ethanolamine salt (WPN) was 0.1250 mg/L. In the field immersion and spray tests, the concentration of nano-suspension as only 1/5 of active content of WPN achieved the same molluscicidal effect with WPN. Conclusions The nano-suspension has higher molluscicidal effect than WPN and the novel formulation of niclosamide has more advantages than WPN, it is useful for snail control in the field.
2.Construction and evaluation of a novel dendrimer vector-DNA vaccine for schistosomiasis japonica
Xiaoting WANG ; Yinchang ZHU ; Qiuduan GAO ; Lingxiang GUO ; Xinsong LI
Chinese Journal of Schistosomiasis Control 2010;22(1):5-12
Objective To construct and evaluate a novel PAMAM dendrimer vector-DNA vaccine for schistosomiasis japonica.Methods Lysine was used to modify 4.0G PAMAM.and the modified product PAMAM-Lys was synthesized.Agarose gel electrophoresis was used to confirm the composite ratio of plasmid DNA and dendrimer.Micrestructure of the compound was observed by using transmission electronic microscopy,and the stability was analyzed by using electrophoresis.The viability of the cells transfected with dendrimers was evaluated by using a MTT technique in vitro.Fiftyty mice were immunized with purified plasmid pJW4303,pJW4303-Sj23 dendrimer PAMAM-Lys and compound PAMAM-Lys/pJW4303-Sj23,respectively.The specific antibodies of the mice in each group were detected to access the immunoreactivity.Results The agarese gel electrophoresis showed that when the charge ratio of the dendrimer vector and DNA was between 2 and 4,the positive and negative charges could be counteraeted completely,and the compound was blocked completely by DNA electrophoresis.The obscrvation results with transmission electronic microscopy showed that the composition of dendrimer vector and DNA caused shrink of DNA structure.Dendrimer-DNA compound had a good stability.MTT showed the modified dendrimer vector and DNA compound system produced a lower cell toxicity on 293T cell than the unmodified Ones.Thk levels of specific antibodies of the mice immunized with PAMAM-Lys/pJW4303Sj23 were significantly higher than those of the mice immunized with naked DNA vaccine(P<0.05).Conclusions The lysinemodified PAMAM-lys is an excellent vector,and has an appropriate biocompatibility.Lysine-modification can reduce the cell toxicity of PAMAM dendrimer significantly.PAMAM-Lys can enhance the immunoreactivity of DNA vacmine which merits further application in schistosomiasis DNA vaccine.
3.Epidemiological study of schistosomiasis japonica on liver and spleen with ultrasonographical assessment among inhabitants in Dongting Lake endemic areas
Zongchuan LIU ; Xinsong LUO ; Xinling YU ; Hongbin HE ; Yuesheng LI
Chinese Journal of Schistosomiasis Control 1991;0(05):-
Objective To understand the morbidity of schistosomiasis japonica and health status of the liver and spleen of residents in a village and to evaluate the application of ultrasound on schistosomiasis epidemiology. Methods A total of 454 residents aged 5-65 years were examined by methods of Kato-Katz and ultrasound as well as disease history inquiry. Results The positive rate was 9.38% by stool examination, with no significant difference between males and females. The intensity of the infection among population was 5.70 eggs per gram of stool (EPG), with significant difference between males and females. The stool positive rate and EPG in farmers and students were the highest. Among 10.66% of the males and 8.10% of the females, as well as in 23.81% of the stool positive and 8.31% of the stool negative, the parenchyma of the liver was abnormal(≥GradeⅡ),with significant difference between males and females and between the stool positive and the stool negative. The abnormal rate of liver parenchyma went up with the age. Conclusion Ultrasound can evaluate the health status of inhabitants with schistosomiasis japonica and improve the compliance rate of residents to praziquantel chemotherapy.
4.Preparation and lacrimal pharmacokinetics of eye drops of puerarin liposomes in rabbit tears.
Yun DENG ; Jinku XU ; Xinsong LI
China Journal of Chinese Materia Medica 2010;35(3):301-304
OBJECTIVETo prepare eye drops of puerarin liposomes and investigate its lacrimal pharmacokinetics in rabbit tears.
METHODPuerarin liposomes were prepared by reverse phase evaporation technique. The liposomes and free puerarin were separated by SephadexG-50 chromatography and then encapsulation ratio of liposomes was determined in detail. Micromorphology of liposome particles was observed by electronic transmission microscope and the size distribution of the liposomes was analyzed by laser particle size analyzer. The concentration of puerarin in rabbit's tears was determined by HPLC after ocular administration of 50 microL puerarin liposomes while puerarin eye drops was chosen as control with the same puerarin concentration. The pharmacokinetic parameters were calculated by software program 3P97 according to one-compartment mode.
RESULTGlobal liposome nanoparticles with diameter of about 195.7 nm were prepared successfully. The encapsulation ratio of puerarin in the liposomes was 48.3%. The mean residence time (MRT) value and the area under concentration (AUC) of puerarin in liposome were 3.89 and 3.06 times more than those of puerarin eye drops.
CONCLUSIONLiposomes as a drug carrier can greatly increase the concentration of puerarin in tears, enhance the pre-ocular retention time than that of eye drops.
Animals ; Chromatography, High Pressure Liquid ; Isoflavones ; chemistry ; pharmacokinetics ; Liposomes ; chemistry ; pharmacokinetics ; ultrastructure ; Microscopy, Electron, Transmission ; Ophthalmic Solutions ; chemistry ; pharmacokinetics ; Rabbits ; Tears ; chemistry
5.In vivo degradation and tissue compatibility of poly-L-lactide/beta-tricalcium phosphate composite rods for internal fixation of bone fractures.
Xinsong LI ; Jun ZOU ; Guohua ZHU ; Xinsheng QI ; Yuepu PU
Journal of Biomedical Engineering 2007;24(1):81-86
Abstract Poly-l-lactide/beta-tricalcium phosphate (PLLA/betaTCP) composite was obtained by combining ground beta-TCP with PLLA, and absorbable rods were prepared by injection moulding. Degradations of the rods were investigated by scanning electron microscope (SEM), mass loss, molecular weight and bending strength changes. At the beginning of in vivo degradation of the rods, the molecular weight of PLLA decreases sharply with the less mass losses of the rods. As in vivo degradation progress, the surfaces of the rods changed roughly, while micropores and fine groove were observed in the inner part of the rods. The bending strength of composite rods decreased from 151 MPa to 106 MPa after in vivo degradation of 12 weeks. Tissue test reveal that PLLA/beta-TCP composite has good tissue compatibility compared with PLLA.
Absorbable Implants
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Animals
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Biocompatible Materials
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chemistry
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Calcium Phosphates
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chemistry
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Fractures, Bone
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therapy
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Internal Fixators
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Lactic Acid
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chemistry
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Materials Testing
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Polyesters
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Polymers
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chemistry
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Rabbits
6.Cross-Linking Methods of the Silk Protein Hydrogel in Oral and Craniomaxillofacial Tissue Regeneration
Xiujuan LI ; Yuanjiao LI ; Xinsong ZHANG ; Jie XU ; Jie KANG ; Bing LI ; Bin ZHAO ; Lu WANG
Tissue Engineering and Regenerative Medicine 2024;21(4):529-544
BACKGROUND:
Craniomaxillofacial tissue defects are clinical defects involving craniomaxillofacial and oral soft and hard tissues.They are characterized by defect-shaped irregularities, bacterial and inflammatory environments, and the need for functional recovery.Conventional clinical treatments are currently unable to achieve regeneration of high-quality oral craniomaxillofacial tissue. As a natural biomaterial, silk fibroin (SF) has been widely studied in biomedicine and has broad prospects for use in tissue regeneration.Hydrogels made of SF showed excellent water retention, biocompatibility, safety and the ability to combine with other materials.
METHODS:
To gain an in-depth understanding of the current development of SF, this article reviews the structure, preparation and application prospects in oral and craniomaxillofacial tissue regenerative medicine. It first briefly introduces the structure of SF and then summarizes the principles, advantages and disadvantages of the different cross-linking methods (physical cross-linking, chemical cross-linking and double network structure) of SF. Finally, the existing research on the use of SF in tissue engineering and the prospects of using SF with different cross-linking methods in oral and craniomaxillofacial tissue regeneration are also discussed.
CONCLUSIONS
This review is intended to show the advantages of SF hydrogels in tissue engineering and provides theoretical support for establishing novel and viable silk protein hydrogels for regeneration.