A peptide functionalized poly(ethylene glycol) (PEG) hydrogel for investigating the influence of biochemical and biophysical matrix properties on tumor cell migration

Abstract

To address the challenges associated with defined control over matrix properties in 3D cell culture systems, we employed a peptide functionalized poly(ethylene glycol) (PEG) hydrogel matrix in which mechanical modulus and adhesive properties were tuned. An HT-1080 human fibrosarcoma cell line was chosen as a model for probing matrix influences on tumor cell migration using the PEG hydrogel platform. HT-1080 speed varied with a complex dependence on both matrix modulus and Cys-Arg-Gly-Asp-Ser (CRGDS) adhesion ligand concentration, with regimes in which motility increased, decreased, or was minimally altered being observed. We further investigated cell motility by forming matrix interfaces that mimic aspects of tissue boundaries that might be encountered during invasion by taking advantage of the spatial control of the thiol-ene photochemistry to form patterned regions of low and high cross-linking densities. HT-1080s in 100 Pa regions of patterned PEG hydrogels tended to reverse direction or aggregate at the interface when they encountered a 360 Pa boundary. In contrast, HT-1080s were apparently unimpeded when migrating from the stiff to the soft regions of PEG peptide hydrogels, which may indicate that cells are capable of “reverse durotaxis” within at least some matrix regimes. Taken together, our results identified matrix regimes in which HT-1080 motility was both positively and negatively influenced by cell adhesion or matrix modulus.

Thiol–norbornene photoclick hydrogels for tissue engineering applications

“…cultured human fibrosarcoma cells (HT-1080) in an MMP-degradable thiol-norbornene hydrogel and studied HT-1080 cell migration mechanism in 3D. 86-88 Wang et al . established a brain tumor model by encapsulating glioblastoma (GBM) cells (U87) in HA entrapped 8-arm PEG-norbornene hydrogel cross-linked with MMP-sensitive cross-linkers.…”

Characterization of the crosslinking kinetics of multi-arm poly(ethylene glycol) hydrogels formed via Michael-type addition

“…Despite the improved crosslinking density of hydrogels prepared with 4-arm PEG and tri-functional crosslinkers, there are still limitations on the extent of modification with RGD. Furthermore, a higher concentration of monofunctional peptides results in a greater degree of swelling, which contributes to dilution of the incorporated bioactive molecule concentrations in the hydrogel 19 .…”

Stable engineered vascular networks from human induced pluripotent stem cell-derived endothelial cells cultured in synthetic hydrogels

“…Hydrogels formed via thiol-ene photopolymerization represent an emerging class of cell culture materials [36, 37] that are formed through a radical-initiated step-growth mechanism that couples thiols and alkenes with high specificity [38]. A growing body of literature has demonstrated the versatility of thiol-ene photochemistry for incorporating biomolecules such as peptides, growth factors, gelatin, and hyaluronic acid into synthetic hydrogels [4, 35–37, 39–47]. Hydrogels formed via thiol-ene photopolymerization enable spatial patterning of biochemical and mechanical properties [35, 39–41], sequestering and controlled release of growth factors [45], rapid photopolymerization for 3D bioprinting of encapsulated cells [44], and protein-free backgrounds for identifying ECM components deposited in the matrix during cellular remodeling [47].…”

“…A growing body of literature has demonstrated the versatility of thiol-ene photochemistry for incorporating biomolecules such as peptides, growth factors, gelatin, and hyaluronic acid into synthetic hydrogels [4, 35–37, 39–47]. Hydrogels formed via thiol-ene photopolymerization enable spatial patterning of biochemical and mechanical properties [35, 39–41], sequestering and controlled release of growth factors [45], rapid photopolymerization for 3D bioprinting of encapsulated cells [44], and protein-free backgrounds for identifying ECM components deposited in the matrix during cellular remodeling [47]. Thus, thiol-ene chemistry offers a potentially powerful tool for modeling vascular morphogenesis by providing control over a wide range of matrix properties relevant to blood vessel formation [4, 35].…”