Mathematical Model for Surface‐Initiated Photopolymerization of Poly(ethylene glycol) Diacrylate

Abstract

Summary: A general mathematical model has been developed to describe the surface initiated photopolymerization of PEG‐DA forming crosslinked hydrogel membranes upon the surface of a substrate. Such membranes are formed by photopolymerizing a PEG‐DA prepolymer solution by initiation with eosin‐Y‐functionalized surfaces and TEA using VP as accelerator. Experimental measurements of the thickness of hydrogel membranes compare well with the model. The model is developed by using the pseudo‐kinetic approach and the method of moments, and is capable of predicting the crosslink density and thickness of the hydrogel membrane. Parametric sensitivity of the effects of PEG‐DA, VP and coinitiator TEA concentration towards the crosslink density and the thickness of the hydrogel is also investigated. The results obtained for different PEG‐DA and VP concentrations suggest that the concentration ratio of these two monomers is a key parameter in controlling the gel thickness and permeability. This model can also be applied to systems where drugs, proteins or cells are encapsulated through surface initiated photopolymerization to predict the growth and crosslink density profiles of the encapsulating membrane. In a previous study we have experimentally demonstrated that these membranes could be made to attach covalently to the surface of the underlying substrate.Comparison of experimental measurements and model simulation of PEG‐DA hydrogel membrane thickness versus laser duration at high PEG‐DA concentrations.imageComparison of experimental measurements and model simulation of PEG‐DA hydrogel membrane thickness versus laser duration at high PEG‐DA concentrations.

Mathematical Model for Microencapsulation of Pancreatic Islets within a Biofunctional PEG Hydrogel

“…The thickness of the hydrogel membrane was measured for various VP prepolymer concentrations at a polymerization time of 150 s. An optimization routine similar to the ones developed in the earlier studies of Kızılel et al was used to determine the best estimated values of the parameters. [15] Next, in order to obtain simulation results for the thickness, crosslink density and composition of GLP-1 within the Table 2. Physical and kinetic constants for PEG-DA, VP, and acrl-PEG-GLP-1 copolymerization.…”

“…[14][15][16][17] Those models greatly improved our understanding of such a complex polymerization system and provided important information on the effect of parameter variation (e.g., monomers or initiator concentration, light intensity, duration of photopolymerization) on properties of the membrane such as thickness, crosslink density, and gelation.…”

Engineering of bio-hybrid materials by electrospinning polymer-microbe fibers

“…The cytocompatibility of the crosslinking step is critical to the ultimate success of this study. Although polymerization of monomers with carbon-carbon double bonds has been investigated extensively in the past using photopolymerization/ photo cross-linking (40)(41)(42), this method cannot be used for the preparation of cross-linked FDMA fibers encapsulated with bacteria, both because UV light has known microbicidal properties and because photopolymerization cannot be carried out uniformly in a large or thick system. Furthermore, the penetration depth of UV light is quite limited, and the distribution of light is inhomogeneous (43).…”

Synthetic PEG Hydrogels as Extracellular Matrix Mimics for Tissue Engineering Applications

“…Other studies of computational modeling of free-radical photopolymerization of crosslinked PEGDA hydrogels formed via interfacial photopolymerization have predicted the formation of crosslink density gradients within planar hydrogel surfaces as a function of space and time (Kizilel et al, 2006). These models were based on previous models of gel formation occurring via free-radical crosslinking of vinyl and divinyl monomers developed by Gossage (Gossage, 1997).…”