Impact of secondary reactive species on the apparent decoupling of poly(ethylene glycol) diacrylate hydrogel average mesh size and modulus

Abstract

Poly(ethylene glycol) diacrylate (PEGDA) hydrogels are widely used in biotechnology due to their in situ crosslinking capacity and tunable physical properties. However, as with all single component hydrogels, the modulus of PEGDA networks cannot be tailored independently of mesh size. This interdependence places significant limitations on their use for defined, 3D cell-microenvironment studies and for certain controlled release applications. The incorporation of secondary reactive species (SRS) into PEGDA hydrogels has previously been shown to allow the identification of up to 6 PEGDA hydrogel formulations for which distinct moduli can be obtained at consistent average mesh size (or vice versa). However, the modulus and mesh size ranges which can be probed by these formulations are quite restricted. This work presents an in-depth study of SRS incorporation into PEGDA hydrogels, with the goal of expanding the space for which “decoupled” examination of modulus and mesh size effects is achievable. Towards this end, over 100 PEGDA hydrogels containing either N-vinyl pyrrolidone or star PEG-tetraacrylate as SRS were characterized. To our knowledge, this is the first study to demonstrate that SRS incorporation allows for the identification of a number of modulus ranges that can be probed at consistent average mesh size (or vice versa).

Assessment of the ability of poly(l‐lysine)–poly(ethylene glycol) (PLL–PEG) hydrogels to support the growth of U87‐MG and F98 glioma tumor cells

“…The parameters tested to characterize the physicochemical properties of the hydrogels (i.e., elastic modulus and mesh size) matched referenced values in the literature for PEG‐DA‐based hydrogels synthetized by other chemical reaction processes . This validated the simpler and affordable process suggested here.…”

A Three-Dimensional Chondrocyte-Macrophage Coculture System to Probe Inflammation in Experimental Osteoarthritis

“…Poly(ethylene glycol) diacrylate (PEGDA)-based hydrogels were used in this study for the establishment of the 3D coculture system, due to their widespread use in cartilage tissue engineering, [34][35][36][37] their easily tunable mechanical properties, 38,39 and their ability to significantly resist cell adhesion even in serum-containing culture environments relative to many biomaterials. 34,40,41 This latter property permits desired cell adhesion to be ''programmed'' into the PEGDA network through conjugation of bioactive moieties.…”

Probing the response of human osteoblasts following exposure to sympathetic neuron‐like PC‐12 cells in a 3D coculture model

“…PEGDA was synthesized from PEG‐diol (6 kDa, Sigma–Aldrich) at ∼99% acrylation as reported previously . Concurrently, NH 2 ‐Arg‐Gly‐Asp‐Ser‐COOH (RGDS; American Peptide Company) was reacted with 3.4 kDa acryoyl‐PEG‐succinimidylvalerate (ACRL‐PEG‐NHS; Laysan Bio) at a 1:3 molar ratio for 2 h in 50 mM sodium bicarbonate buffer (pH 8.5).…”

“…Polymer synthesis and functionalization with cell adhesive peptides PEGDA was synthesized from PEG-diol (6 kDa, Sigma-Aldrich) at 99% acrylation as reported previously. 34 Concurrently, NH 2 -Arg-Gly-Asp-Ser-COOH (RGDS; American Peptide Company) was reacted with 3.4 kDa acryoyl-PEGsuccinimidylvalerate (ACRL-PEG-NHS; Laysan Bio) at a 1:3 molar ratio for 2 h in 50 mM sodium bicarbonate buffer (pH 8.5). The product (ACRL-PEG-RGDS) was purified by dialysis, lyophilized, and stored at 2808C until further use.…”