Polymerizable superoxide dismutase mimetic protects cells encapsulated in poly(ethylene glycol) hydrogels from reactive oxygen species‐mediated damage

Abstract

A polymerizable superoxide dismutase mimetic (SODm) was incorporated into poly(ethylene glycol) (PEG) hydrogels to protect encapsulated cells from superoxide-mediated damage. Superoxide and other small reactive oxygen species (ROS) can cause oxidative damage to donor tissue encapsulated within size exclusion barrier materials. To enzymatically breakdown ROS within biomaterial cell encapsulation systems, Mn(III) Tetrakis[1-(3-acryloxy-propyl)-4-pyridyl] porphyrin (MnTTPyP-acryl), a polymerizable manganese metalloporphyrin SOD mimetic, was photopolymerized with PEG diacrylate (PEGDA) to create functional gels. In unmodified PEG hydrogels, a significant reduction in metabolic activity was observed when encapsulated Min6 β-cells were challenged with chemically generated superoxide. Cells encapsulated within MnTPPyP-co-PEG hydrogels, however, demonstrated greatly improved metabolic activity following various superoxide challenges. Further, cells were encapsulated and cultured for 10 days within MnTPPyP-co-PEG hydrogels and challenged with superoxide on days 4, 6, and 8. At the conclusion of this study, cells in blank PEG hydrogels had no observable metabolic activity but when encapsulated in MnTPPyP-functionalized hydrogels, cells retained 60 ± 5% of the metabolic activity compared to untreated controls.

Micropatterned Cell–Cell Interactions Enable Functional Encapsulation of Primary Hepatocytes in Hydrogel Microtissues

“…For the hydrogel scaffold material, 10% w/w PEG diacrylate (PEG-DA, 20 kDa) was chosen, because it is (1) permeable enough to enable the diffusion of oxygen/nutrients/proteins to and from the cells, 42 (2) biologically/immunologically inert, and (3) can be functionalized with acrylate-containing ligands. 23,43,44 As a control condition, hepatocytes were randomly seeded in collagencoated but unpatterned six-well plates at 600,000 cells/well, which was chosen to match the theoretical number of cells that would seed in a 50 mm-island patterned well assuming 5.6 hepatocytes per island. At this density, cells on the unpatterned surfaces are able to make chance cell contacts, as they seed in 2D and form loose cords of cells when detached (Fig.…”

Hydrogen‐Bonded Multilayers of Tannic Acid as Mediators of T‐Cell Immunity

“…[xlvii] There are only a few studies on functionalization of coatings with the active compounds, mostly limited to conjugation to islets or copolymerization into gels on the islet surfaces. [xlviii,xlix] …”

Tissue engineering 2.0: guiding self-organization during pluripotent stem cell differentiation

“…The pore size of capsules can be controlled to a minimum of 7 nm [76]. The effect of eliminating signals on the maturation of transplanted pancreatic progenitors may be determined by encapsulating in hydrogels that sequester particular molecules [77–79], or eliminate metabolites with immobilized enzymes [80]. The signals inducing pancreatic progenitor maturation into beta-like cells in vivo may be investigated using these tissue engineering technologies.…”