Viscoelastic Characterization and Modeling of Gelation Kinetics of Injectable In Situ Cross-Linkable Poly(lactide-co-ethylene oxide-co-fumarate) Hydrogels

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• 作者：Alireza S. Sarvestani ; Xuezhong He ; Esmaiel Jabbari
• 刊名：Biomacromolecules
• 出版年：2007
• 出版时间：February 2007
• 年：2007
• 卷：8
• 期：2
• 页码：406 - 415
• 全文大小：354K
• 年卷期：v.8,no.2(February 2007)
• ISSN：1526-4602

文摘

Cell transplantation by injection of biodegradable hydrogels is a recently developed strategy for the treatment ofdegenerated tissues. A cell carrier should be cytocompatible, have suitable working time and rheological propertiesfor injection, and harden in situ to attain dimensional stability and the desired mechanical strength. Hydrophilicmacromer/cross-linker polymerizing systems, due to the relatively high molecular weight of the macromer andits inability to cross the cell membrane, are very attractive as injectable cell carriers. The objective of this researchwas to determine the effects of cross-linker, initiator, and accelerator concentrations on the gelation kinetics andultimate modulus of a biodegradable, in situ cross-linkable poly(lactide-co-ethylene oxide-co-fumarate) (PLEOF)macromer. The in situ polymerizing mixture consisted of PLEOF macromer, methylene bisacrylamide cross-linker, and a neutral redox initiation system of ammonium persulfate initiator and tetramethylethylenediamineaccelerator. Measurement of the time evolution of the viscoelastic properties of the network during the sol-geltransition showed the important influence of each component on the gel time and stiffness of the hydrogels. Akinetic model was developed to predict the modulus as a function of composition. Model predictions were consistentwith most of the experimental findings. The values of the storage and loss moduli at the gel point were found tobe approximately equal for samples with equal PLEOF concentrations, resulting in a simple method to predictthe gelation time based on the Winter-Chambon criterion, with the use of the proposed kinetic model. Theresults of this study can be coupled with component cytocompatibility measurements to predict the effect ofcomposition on the viability of the cells encapsulated in the hydrogel matrix.