BACKGROUND: Simply used natural materials-prepared scaffolds such as collagen, gelatin and fibrin solve problems of biocompatibility, but its degradation is rapid, and cannot induce new tissues, but collapse is found as cell scaffolds.OBJECTIVE: To explore and determine the property of biological degradable three-dimensional porous scaffolds using silk fibroin-chitosan composite.DESIGN, TIME AND SETTING: The material observational study was performed at the Institute of Bioengineering, Zhejiang Academy of Medical Science from June 2008 to June 2009.MATERIALS: Spring silk cocoon was presented by a silkworm farmer from Huangdunmiao village, Maqiao town, Haining City,Zhejiang Province, China. Chitosan was produced by Shanghai Bo'ao Biological Technology.METHODS: 15 g/L silk fibroin solution was made by degumming, salvation and dialysis. Chitosan was dissolved in 2% acetic acid solution to prepare 25 g/L chitosan-acetic acid solution. Two solutions were mixed to prepare six silk fibroin/chitosan solutions, and mass ratio was 10: 0, 5: 5, 4: 6, 3: 7, 2: 8, 0:10. These solutions were separately sucked in a 24-well plate. Following exhausting gas vacuole at 4 ℃, precooling was performed at -20 ℃ for 12 hours, followed by cryodesiccate for 30 hours. Samples were then hydrated in ethanol, neutralized in NaOH-alcohol for 1 hour, washed and then frozen to dry.MAIN OUTCOME MEASURES: Optical microscope and scanning electron microscope were used to observe pore size and structure of various mass ratio-prepared scaffold. Modified liquid substitution method was utilized to measure porosity of various scaffolds. The degradable rate of various scaffolds was determined at 4 weeks in vitro.RESULTS: Silk fibroin/chitosan of 10: 0 mass ratio-prepared scaffold had rough fluffy pore, was brittle, with high dissolve-loss rates. On the contrary, chitosan-prepared scaffold was hard, without enough elasticity following freeze-dry. The composite scaffold of 5: 5, 4: 6, 3: 7 and 2: 8 following freeze-dry was loose and soft, similar to sponge. With increased chitosan concentration,scaffold hardness increased. There were evenly distributed, detailed eyelets on the scaffold. Under the optical microscope,various pores were irregular; each pore closely connected and linked together; pore size was even, 20-100 μm. With increased chitosan concentration, pore size was gradually reduced. Scaffold porosity determination results displayed that mass ratio of silk fibroin/chitosan 4: 6 group > 5: 5 group > 3: 7 group > 2: 8 group. Compared with 2: 8 group, the porosity was significantly increased in the 5: 5 and 4: 6 groups (P < 0.05). No significant difference was detected in volume expansibility in the silk fibroin/chitosan composite scaffold of various mass ratios (P > 0.05). The degradation was slowest in the 2: 8 group, and fastest in the 5: 5 group at 4 weeks.CONCLUSION: Regarding physical and chemical properties, composite scaffold made by silk fibroin/chitosan showed significant superiority compared with scaffold made by silk fibroin or chitosan alone. Of them, silk fibroin/chitosan mass ratio of 5: 5 and 4: 6 are accorded with the requirement of cartilage tissue engineering.

OBJECTIVE: To prepare chitosan microspheres encapsulated transforming growth factor β1 (TGFβ1), and to analyze its property. METHODS: The chitosan was dissolved in 2% acetic acid to prepare chitosan microspheres encapsulated TGFβ1 with emulsification cross-linking method, Tween 80 and sodium polyphosphate were served as emulsifying agent and cross-linking agent, respectively. Meanwhile, chitosan microspheres and containing bovine serum albumin chitosan microspheres were prepared as blank control and experimental control groups. The morphology and diameter of 3 kinds of microspheres were observed, and the dispersion and in vitro release of chitosan microspheres encapsulated TGFβ1 were detected, furthermore, the water absorption expansion rate of blank control and experimental control groups were measured. RESULTS: Scanning electron microscopy showed that the microspheres diameter in the blank group was approach 15 μm, with smooth surface and plenty of tiny pores. However, the microspheres in the other 2 groups were distributed uniformly with approximately 1 μm in diameter, the surface was smooth. The chitosan microspheres encapsulated TGFβ1 released fast at begin 12 hours, and then gentled gradually, with 53.5% release ratio within 6 days. The increased mass of microspheres in the blank control and experimental control groups reached a balance after 1 hour, both of which were over 700%,in particular larger in the acid environment. CONCLUSION: Chitosan microspheres encapsulated TGFβ1 prepared by emulsification cross-linking method exhibit high yield and good drug release. The strong water absorption expansion rate of chitosan microspheres requires aperture size, as well as intensity of bone tissue engineered scaffold.

Objective: To investigate the contamination of phthalic acid esters (PAEs) and assess the health risk of PAEs contamination in market-available yellow rice wine in Huzhou City, Zhejiang Province, so as to provide the safety safeguard for consuming yellow rice wine. Methods: Yellow rice wine samples were collected from markets in Huzhou City from 2021 to 2022, and 16 PAEs were determined in yellow rice wine using magnetic solid-phase extraction coupled with gas chromatography-tandem mass spectrometry. The carcinogenic and non-carcinogenic risks of PAEs were evaluated using the health risk models proposed by United States Environmental Protection Agency. Results: A total of 75 yellow rice wine samples were collected, and 44 samples were detected with PAEs contamination (58.67%). Dimethyl phthalate (DMP), di-isobutyl phthalate (DIBP) and di-butyl phthalate (DBP) were detected, and there were 17 samples (22.67%) detected with DBP overdose (DMP and DIBP had no limit standard). DMP, DBP and DIBP, which were not classified as Class 2B and higher carcinogens by WHO's International Agency for Research on Cancer, had no definitive carcinogenic risks. Under mean PAEs, the five types of yellow rice wine all had no carcinogenic risks. Under 75% percentile of PAEs concentrations, the DBP in beverage wine with plastic packaging had a carcinogenic risk score of 1.207 5, with a gross carcinogenic risk score of 1.207 5. Under the maximum PAEs concentration, the ross carcinogenic risk scores of cooking wine with plastic packaging, beverage wine with plastic packaging, beverage wine with glass bottle packaging, and beverage wine with jar packaging were 2.751 0, 2.782 0, 1.298 2 and 2.944 0, presenting non-carcinogenic risks. Conclusion There is PAEs contamination in market-available yellow rice wine in Huzhou City, and no carcinogenic risk is evaluated. Non-carcinogenic health risk requires to be given a high priority.

Objective: To develop a magnetic solid-phase extraction combined with gas chromatography-tandem mass spectrometry (GC-MS/MS) based on pyrrole-modified magnetic nanoparticles to determine 16 types of phthalic acid esters (PAEs) in commercial liquors. Methods : Fe3O4 magnetic nuclei were prepared by hydrothermal synthesis, and the polypyrrole-modified magnetic nanomaterials were prepared with the chemical oxidation method. Magnetic solid-phase extraction of beer, grape wine, rice wine and Chinese spirits was performed at 10% alcohol by volume, extraction duration of 20 min and ethyl acetate elution of 10 min, followed by addition of 1 g NaCl for reduction of emulsification effect. The 16 types of PAEs were determined using GC-MS/MS with DB-5MS capillary column (30 m×250 μm, 0.25 μm) under the mode of electron impact ionization (EI) and dynamic multiple reaction monitoring (dMRM), with quantitative analysis using the external standard method. The standard curve, detection limit, spike recovery rate and precision of GC-MS/MS for determination of 16 types of PAEs were evaluated. Results: Pyrrole was successfully embedded onto the surface of magnetic nanoparticles in the form of polymer, and the magnetic nanoparticles modified by polypyrrole were well characterized, showing unapparent matrix and emulsification effects. There was a good linear relationship for the 16 types of PAEs at 50 to 5 000 ng/mL (r=0.999 5-0.999 9), and the spike recovery rate of 16 types of PAEs ranged from 71.61% to 110.50% at 100, 500 and 1 000 μg/kg, with relative standard deviations of 3.78% to 7.41%, detection limits of 0.02 to 1.47 μg/kg. PAEs were detected in 20 out of 50 liquor samples, with 30.00%, 60.00%, 40.00% and 70.00% detection rates in beer, grape wine, rice wine and Chinese spirits, respectively. Conclusions This method is sensitive to determine 16 types of PAEs in liquor samples, with unapparent matrix and emulsification effects, and the polypyrrole-modified magnetic composite nanoparticles present high adsorption of PAEs in liquor samples, which is feasible for monitoring of PAEs in multiple types of liquor samples.

AIM: To investigate the therapeutic effect of chloride channel blocker tamoxifen on hypoxia pulmonary hypertension in rats.METHODS: Sixty male Wistar rats were randomly divided into therapeutic group(H/Q group),hypoxia group(H group),normal control group(C group).Mean pulmonary artery pressure(mPAP),the ratio of the weight of right ventricle to that of left ventricle plus septum[RV(LV+S)],and the ratio of the pulmonary arteriole wall area to that of vascular total area(WA/TA),were measured at 4,7,14,21 days.RESULTS:The mPAP began to increase from 7 days,and reached peak at 21 days in hypoxia group,however it is obviously lower in therapeutic group at same time.The ratio of RV(LV+S) began to increase from 14 days,and reached peak at 21 days in hypoxia group,however it is obviously lower in therapeutic group at same time.The ratio of WA/TA at 21 days in hypoxia group was significantly higher than therapeutic group,respectively(P

Objective:To investigate the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang region and determine the relationship between ethnicity and mutations.Method:DNA were extracted from peripheral blood of 125 deaf patients from Urumqi and Korla special educational schools in Xinjiang.Audiologic examinations showed that all patients had severe to profound bilateral sensorineural hearing hoss. The coding region of GJB2 gene, SLC26A4 and mitochondrial DNA target fragments were amplified by polymerase chain reaction(PCR).Mutations in GJB2 gene, SLC26A4IVS7-2 A>G, mtDNA 1494C>T and mtDNA1555 A>G were identified by sequencing analysis.Result:Allelic Frequency of the GJB2 35delG and SLC26A4IVS7-2 A>G mutations in Han deaf students were 7.4%and 10.1%,respectively, whereas not found in Uigur deaf groups.The difference was statistically significant. We did not find significant differences in GJB2 235 delC, 299-300delAT, mtDNA A1555G and C1494T allelic frequency between Uigur and Han students.Conclusion:Prevalence of the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang has a great diversity.

10.3969/j.issn.2095-4344.2013.25.016

BACKGROUND: It is difficult to achieve satisfactory results with the traditional treatment of large-area skin defects and deep burns. OBJECTIVE: To test the treatment effect of an active dressing film made of a mixture of fibrin glue and bone marrow mesenchymal stem cells (BMSCs) for repairing burn wounds on the skin of rats. METHODS: Two scald wounds were made on the back of each rat. A total of 30 scald wounds were randomly divided into 3 groups, with 10 wounds in each group. In the experimental treatment group, the scald wounds were covered with the fibrin glue and BMSC mixture. The wounds of the experimental control group were covered with fibrin glue only. No intervention was administered to the blank control group. Thirty days after treatment, pathological sections were cut from the scalded local tissues of all rats from the 3 groups and observed with a microscope. RESULTS: The speed of scald wound healing in the experimental treatment group was faster than the other 2 groups. In the experimental treatment group, histopathological analysis revealed that the sebaceous glands showed obviously proliferous at the edge of the new tissue and gradually extended to the deep dermal layer of the new tissue. CONCLUSION: BMSCs may have an active role in promoting skin tissue repair and generating skin appendages. Allogeneic BMSCs mixed with fibrin glue can contribute to the quick formation of a film-like gel over the scald wounds, which might be of significance for emergency treatment and skin-grafting operations.
Animals ; Bandages ; Bone Marrow* ; Burns ; Emergency Treatment ; Fibrin Tissue Adhesive* ; Mesenchymal Stromal Cells* ; Rats* ; Sebaceous Glands ; Skin* ; Skin, Artificial ; Tissue Engineering ; Wound Healing ; Wounds and Injuries

OBJECTIVE: To investigate the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang region and determine the relationship between ethnicity and mutations. METHOD: DNA were extracted from peripheral blood of 125 deaf patients from Urumqi and Korla special educational schools in Xinjiang. Audiologic examinations showed that all patients had severe to profound bilateral sensorineural hearing hoss. The coding region of GJB2 gene, SLC26A4 and mitochondrial DNA target fragments were amplified by polymerase chain reaction (PCR). Mutations in GJB2 gene, SLC26A4IVS7-2 A>G, mtDNA 1494C>T and mtDNA1555 A>G were identified by sequencing analysis. RESULT: Allelic Frequency of the GJB2 35delG and SLC26A4IVS7-2 A>G mutations in Han deaf students were 7.4% and 10.1%, respectively, whereas not found in Uigur deaf groups. The difference was statistically significant. We did not find significant differences in GJB2 235 delC, 299-300delAT, mtDNA A1555G and C1494T allelic frequency between Uigur and Han students. CONCLUSION Prevalence of the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang has a great diversity.
Adolescent ; Asian Continental Ancestry Group ; genetics ; Child ; China ; ethnology ; Connexin 26 ; Connexins ; genetics ; DNA, Mitochondrial ; genetics ; Deafness ; ethnology ; genetics ; Ethnic Groups ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Membrane Transport Proteins ; genetics ; Mutation ; Persons With Hearing Impairments ; Polymorphism, Genetic ; Sulfate Transporters ; Young Adult

OBJECTIVE: To develop a molecular genetic assay to detect the GJB2 235 delC and mtDNA A1555G mutations simultaneously based on fluorescent labeled multiplex PCR and automatic DNA fragment analyzing techniques. METHOD: One hundred and twenty samples were pooled in our experiment to test the feasibility of new method. The PCRs were performed and the size fragment of PCR products were analyzed on ABI 3100 Genetic Analyzer. Data analysis were taken using the software package of GeneScan and GeneMarker. RESULT: Seventeen samples of DNA with 235 delC and 17 samples with A1555G were tested using this protocol. A false-positive sample without GJB2 235 delC mutation was tested. CONCLUSION This assay can detect both mutations in pooled DNA tests and will be a useful tool for newborn screening and carrier screening for the hereditary hearing loss in Chinese population.
Connexin 26 ; Connexins ; genetics ; DNA Mutational Analysis ; DNA, Mitochondrial ; genetics ; Genetic Testing ; methods ; Hearing Loss ; diagnosis ; genetics ; Heterozygote ; Humans ; Mutation ; Polymerase Chain Reaction ; methods