{"title":"聚合物体系的低温结构研究。66.在添加了尿素的冷冻二甲基亚砜中形成聚乙烯醇冷凝胶,然后用水取代有机介质进行水合的性质和微观结构","authors":"D. A. Michurov, O. Yu. Kolosova, V. I. Lozinsky","doi":"10.1134/S1061933X23600665","DOIUrl":null,"url":null,"abstract":"<p>“Primary” poly(vinyl alcohol) (PVA) cryogels have been obtained by cryogenic processing (freezing at –21.6°C for 12 h followed by defrosting via heating to 20°C at a rate of 0.03°C/min) of a 100 g/L solution of PVA in dimethyl sulfoxide (DMSO) in the absence and presence of urea (2 or 4 mol/L), which exhibits kosmotropic properties in such a medium. Subsequent hydration of the cryogels by replacing DMSO with water causes a decrease in the volume and weight of the samples, as well as leads to a significant increase in the elasticity modulus of resulting “secondary” cryogels. The absolute magnitude of such effects depends both on the concentration of urea in an initial PVA solution and on the volume ratio between gel samples and an aqueous extractant during their hydration. Using optical microscopy, it has been found that the presence of urea in the initial DMSO polymer solution in a concentration close to the limit of its solubility in such a medium induces the formation of a gel matrix with a wide-pore morphology. Since high-modulus secondary PVA cryogels are of great interest as materials for biomedical applications, the possibility of their functioning as carriers of drug delivery systems has been assessed in the work. Ibuprofen sodium salt has been used as a model drug. The analysis of the release kinetics of this substance within the framework of the Weibull function has been employed to show that the dynamic hydrogen bonding of its carboxylate groups with the hydroxyl groups of PVA decelerates the release of the drug from the polymer carrier, i.e., prolongs the release process. At the same time, the rate of the process depends on the urea content in the initial polymer solution most likely due to microstructural differences between the polymer phases of the macropore walls in the cryogel matrix.</p>","PeriodicalId":521,"journal":{"name":"Colloid Journal","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Study of Cryostructuring of Polymer System. 66. Properties and Microstructure of Poly(vinyl alcohol) Cryogels Formed in Frozen Dimethyl Sulfoxide with Additives of Urea and Then Hydrated by Replacing Organic Medium with Water\",\"authors\":\"D. A. Michurov, O. Yu. Kolosova, V. I. Lozinsky\",\"doi\":\"10.1134/S1061933X23600665\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>“Primary” poly(vinyl alcohol) (PVA) cryogels have been obtained by cryogenic processing (freezing at –21.6°C for 12 h followed by defrosting via heating to 20°C at a rate of 0.03°C/min) of a 100 g/L solution of PVA in dimethyl sulfoxide (DMSO) in the absence and presence of urea (2 or 4 mol/L), which exhibits kosmotropic properties in such a medium. Subsequent hydration of the cryogels by replacing DMSO with water causes a decrease in the volume and weight of the samples, as well as leads to a significant increase in the elasticity modulus of resulting “secondary” cryogels. The absolute magnitude of such effects depends both on the concentration of urea in an initial PVA solution and on the volume ratio between gel samples and an aqueous extractant during their hydration. Using optical microscopy, it has been found that the presence of urea in the initial DMSO polymer solution in a concentration close to the limit of its solubility in such a medium induces the formation of a gel matrix with a wide-pore morphology. Since high-modulus secondary PVA cryogels are of great interest as materials for biomedical applications, the possibility of their functioning as carriers of drug delivery systems has been assessed in the work. Ibuprofen sodium salt has been used as a model drug. The analysis of the release kinetics of this substance within the framework of the Weibull function has been employed to show that the dynamic hydrogen bonding of its carboxylate groups with the hydroxyl groups of PVA decelerates the release of the drug from the polymer carrier, i.e., prolongs the release process. At the same time, the rate of the process depends on the urea content in the initial polymer solution most likely due to microstructural differences between the polymer phases of the macropore walls in the cryogel matrix.</p>\",\"PeriodicalId\":521,\"journal\":{\"name\":\"Colloid Journal\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.4000,\"publicationDate\":\"2024-01-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Colloid Journal\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://link.springer.com/article/10.1134/S1061933X23600665\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Colloid Journal","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1134/S1061933X23600665","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Study of Cryostructuring of Polymer System. 66. Properties and Microstructure of Poly(vinyl alcohol) Cryogels Formed in Frozen Dimethyl Sulfoxide with Additives of Urea and Then Hydrated by Replacing Organic Medium with Water
“Primary” poly(vinyl alcohol) (PVA) cryogels have been obtained by cryogenic processing (freezing at –21.6°C for 12 h followed by defrosting via heating to 20°C at a rate of 0.03°C/min) of a 100 g/L solution of PVA in dimethyl sulfoxide (DMSO) in the absence and presence of urea (2 or 4 mol/L), which exhibits kosmotropic properties in such a medium. Subsequent hydration of the cryogels by replacing DMSO with water causes a decrease in the volume and weight of the samples, as well as leads to a significant increase in the elasticity modulus of resulting “secondary” cryogels. The absolute magnitude of such effects depends both on the concentration of urea in an initial PVA solution and on the volume ratio between gel samples and an aqueous extractant during their hydration. Using optical microscopy, it has been found that the presence of urea in the initial DMSO polymer solution in a concentration close to the limit of its solubility in such a medium induces the formation of a gel matrix with a wide-pore morphology. Since high-modulus secondary PVA cryogels are of great interest as materials for biomedical applications, the possibility of their functioning as carriers of drug delivery systems has been assessed in the work. Ibuprofen sodium salt has been used as a model drug. The analysis of the release kinetics of this substance within the framework of the Weibull function has been employed to show that the dynamic hydrogen bonding of its carboxylate groups with the hydroxyl groups of PVA decelerates the release of the drug from the polymer carrier, i.e., prolongs the release process. At the same time, the rate of the process depends on the urea content in the initial polymer solution most likely due to microstructural differences between the polymer phases of the macropore walls in the cryogel matrix.
期刊介绍:
Colloid Journal (Kolloidnyi Zhurnal) is the only journal in Russia that publishes the results of research in the area of chemical science dealing with the disperse state of matter and surface phenomena in disperse systems. The journal covers experimental and theoretical works on a great variety of colloid and surface phenomena: the structure and properties of interfaces; adsorption phenomena and structure of adsorption layers of surfactants; capillary phenomena; wetting films; wetting and spreading; and detergency. The formation of colloid systems, their molecular-kinetic and optical properties, surface forces, interaction of colloidal particles, stabilization, and criteria of stability loss of different disperse systems (lyosols and aerosols, suspensions, emulsions, foams, and micellar systems) are also topics of the journal. Colloid Journal also includes the phenomena of electro- and diffusiophoresis, electro- and thermoosmosis, and capillary and reverse osmosis, i.e., phenomena dealing with the existence of diffusion layers of molecules and ions in the vicinity of the interface.