الملخص
BACKGROUND:The structure,physical and chemical properties(such as rheological properties)and biological activity of hyaluronic acid with different molecular weights are quite different.When the degradation degree of non-cross-linked hyaluronic acid is too large and the high-molecular-weight hyaluronic acid is degraded to low-molecular-weight hyaluronic acid,the properties and biological functions of the product will also change,which will affect the use of the product. OBJECTIVE:To review the mechanism of molecular weight degradation of non-cross-linked hyaluronic acid and the impacts of molecular weight degradation on the structure,rheological properties,biological activity and applications of non-cross-linked hyaluronic acid. METHODS:The first author searched the articles related to the molecular weight of hyaluronic acid collected in PubMed,CNKI database and other databases.The high-quality articles with high correlation were screened according to the inclusion and exclusion criteria.The search time was from January 2017 to December 2022.The Chinese and English search terms were"hyaluronic acid,non-cross-linked hyaluronic acid,molecular weight,degradation,structure,rheological properties,biologic activity".Finally,47 articles were included for review and analysis. RESULTS AND CONCLUSION:(1)The molecular weight of non-cross-linked hyaluronic acid is mainly degraded by specific enzymatic hydrolysis and non-specific free radical degradation.(2)The molecular weight degradation of non-cross-linked hyaluronic acid will change its structure and rheological properties,resulting in the untie of polymer network structure,the decrease of rheological properties such as viscosity and viscoelasticity,and the decrease of mechanical properties,which will eventually affect the practical application effect of the product.(3)The biological activity of non-cross-linked hyaluronic acid is molecular weight dependent,and the biological activity of different molecular weight hyaluronic acid is different.Even the same receptor combined with high-molecular-weight hyaluronic acid and low-molecular-weight hyaluronic acid will express completely opposite biological effects.(4)The degradation of molecular weights of non-cross-linked hyaluronic acid will reduce the safety and efficacy of the products,affect their service life and application performance,and ultimately influence the clinical application results.(5)Non-cross-linked hyaluronic acid has great potential as a biodegradable biomaterial in wound healing,tissue engineering,aesthetic medicine and other fields,and further research and understanding of the correlation between molecular weight degradation of non-cross-linked hyaluronic acid and bioactivity is a prerequisite for better development of wound dressings,drug delivery systems and tissue-engineered scaffolds.(6)However,there are currently few studies on the molecular weight degradation of non-cross-linked hyaluronic acid,and it is unclear how to effectively avoid the potential risks associated with the molecular weight degradation of non-cross-linked hyaluronic acid in clinical applications.(7)Therefore,a series of potential risks associated with the molecular weight degradation of non-cross-linked hyaluronic acid during its application,including the effects on its structure,properties and biological activity,and the resulting changes on the body,is one of the future directions that need to be closely investigated.
الملخص
OBJECTIVE@#In this paper, the key points of quality control and safety evaluation of human assisted reproductive medium were summarized to provide reference for the establishment of relevant standards and quality control in the future.@*METHODS@#Through literature research, the key factors of quality control and risk control of human assisted reproductive medium were summarized, and the problems in clinical transformation were discussed.@*RESULTS@#It is very important for the development of human assisted reproduction technology to study the active ingredients and their harmful degradation products and drugs in the culture medium of assisted reproduction.@*CONCLUSIONS@#At present, the biggest challenge is to effectively control the quality of the culture medium for human assisted reproduction, establish corresponding inspection methods and quality standards for the key components, ensure the safety and effectiveness during the product shelf life, and thus improve the success rate of human assisted reproduction technology.
الموضوعات
Humans , Quality Control , Reproduction , Reproductive Techniques, Assistedالملخص
BACKGROUND: Ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for analyzing amino acids in biological samples is simple in sample preparation with a short analysis time, and has high sensitivity and specificity. Until now, it is only applied in analyzing glutamine contents in dialysate, urine and plasma. OBJECTIVE: To establish a method for determining glutamine concentration in human assisted reproductive media by UPLC-MS/MS. METHODS: The UPLC separation was performed on a SUPELCO Discovery HS F5-3 column (15 cm×2.1 mm, 3 μm) at 40 oC. The mobile phase was acetonitrile and water (both containing 0.1％ formic acid) in a gradient elute mode. The flow rate was 0.35 mL/min. Electrospray ionization with a negative-ion and multiple reaction monitoring mode was used. RESULTS AND CONCLUSION: The linearity was achieved in the range of 0.123 7-24.74 mg/L for glutamine (r=0.999 7). The recoveries were 102.9％-108.2％ with the range 2.3％-4.9％ for the relative standard deviation. The limit of qualification was 9.76 μ g/L. The fertilization culture medium containing glutamine was incubated at 37 oC for 96 hours, in which the glutamine content declined 6％ at 24 hours and 15％ at 96 hours respectively compared with initial content. Therefore, the method is simple, specific, accurate and sensitive without sample derivation, and the test time is short. It is suitable for the quality control of human assisted reproductive media and useful for the risk study related to the degradation of glutamine.
الملخص
Bioresorbable vascular scaffolds(BVS) are new treatment strategies of percutaneous coronary intervention. They have been introduced to overcome limitations of bare metal stents (BMS) and drug-eluting stents(DES), since they provide temporary scaffolding and then disappear, liberate the treated vessel from cage. In this article, we review the current status and problems of BVS, various tests required before gaining regulatory approval for clinical use.
الموضوعات
Animals , Absorbable Implants , Coronary Artery Disease , Drug-Eluting Stents , Percutaneous Coronary Intervention , Prosthesis Design , Stents , Tissue Scaffolds , Treatment Outcomeالملخص
BACKGROUND:In the present quality control file or technique standards of in vitro fertilization medium, the indicators of the component contents and detection methods have not been clearly defined. To ensure the safety and effectiveness of these products, we should establish the quality standards as early as possible. OBJECTIVE:To establish a method for determining the three main bioactive constituents of in vitro fertilizationmedium including glucose, lactic acid sodium salt, pyruvic acid sodium salt by ultra-high performance liquid chromatography tandem mass spectrometric method (UHPLC-MSMS), and to analyze the content of each constituent. METHODS:The UHPLC-MSMS was used, and UHPLC separation was performed on a SUPELCO Discovery HS F5-3 column (15 cm × 2.1 mm, 3μm) in a gradient elute mode with acetonitrile and water (both containing 0.1%formic acid) as the mobile phase at a flow rate of 0.35 mL/min. The column temperature was 40℃. Mass spectrometry detection was performed with multi-reaction monitoring mode using negative electro spray ionization. RESULTS AND CONCLUSION:The linearity was achieved in the range of 0.1-10μg/mL (r=0.999 8) for glucose, 0.05-5μg/mL (r=0.999 4) for lactic acid sodium salt, and 0.1-10μg/mL (r=0.999 4) for pyruvic acid sodium salt. The recoveries were 96.4%-98.1%with relative standard deviation less than 2.8%. To conclude, the UHPLC-MSMS method is sensitive, rapid, accurate and specific, thus providing a basis for the quality standard study of in vitro fertilization medium.
الملخص
BACKGROUND:Nowadays, the component content of assisted reproductive culture medium and their test methods are unclear in the quality standards. We need to establish the test methods to fil this vacancy, so as to control the quality of assisted reproductive culture medium effectively. OBJECTIVE:To establish an evaluation method for determination of fructose and glucose in assisted reproductive culture medium, thereby based on which to establish the quality standards. METHODS:High performance liquid chromatography-differential refractive index detector was adopted and Rezex RCM-Monosaccharide Ca2+(8%) (300.0 mm×7.8 mm) column was used. The mobile phase was ultrapure water at the flow rate of 0.6 mL/min and the temperature of 80 ℃. RESULTS AND CONCLUSION:Resolution of the peaks of glucose and fructose was 3.2. The linear ranges of glucose and fructose were 30.1-502 mg/L (r=0.999 8) and 102-408 mg/L (r=0.999 8), respectively. The relative standard deviation of reproducibility test was 0.17%and 0.40%, respectively. The relative standard deviation of stability test was 0.22%and 0.73%, respectively. The glucose group and fructose group average recovery rates were 1.22%and 1.38%, respectively. The methodology of High performance liquid chromatography-differential refractive index detector accorded with the requirements. The glucose contents of samples 1 and 2 were 96.7 mg/L and 99.6 mg/L, respectively. The fructose contents of samples 1 and 2 were 208.5 mg/L and 197.4 mg/L, respectively. A reliable, simple, and accurate method was provided for the quality control of assisted reproductive culture medium, which fil s the domestic vacancy in the quality standards for assisted reproductive culture medium.