Hydrogel Encapsulation of Genome-Engineered Stem Cells for Long-Term Self-Regulating Anti-Cytokine Therapy.

Biologic therapies have revolutionized treatment options for rheumatoid arthritis (RA) but their continuous administration at high doses may lead to adverse events. Thus, the development of improved drug delivery systems that can sense and respond commensurately to disease flares represents an unmet medical need. Toward this end, we generated induced pluripotent stem cells (iPSCs) that express interleukin-1 receptor antagonist (IL-1Ra, an inhibitor of IL-1) in a feedback-controlled manner driven by the macrophage chemoattractant protein-1 (Ccl2) promoter.

Mapping Macrophage Polarization and Origin during the Progression of the Foreign Body Response to a Poly(ethylene glycol) Hydrogel Implant.

Poly(ethylene glycol) (PEG) hydrogels hold promise for in vivo applications but induce a foreign body response (FBR). While macrophages are key in the FBR, many questions remain. This study investigates temporal changes in the transcriptome of implant-associated monocytes and macrophages.

Prostaglandin E2 and Its Receptor EP2 Modulate Macrophage Activation and Fusion .

The foreign body response (FBR) has impaired progress of new implantable medical devices through its hallmark of chronic inflammation and foreign body giant cell (FBGC) formation leading to fibrous encapsulation. Macrophages are known to drive the FBR, but efforts to control macrophage polarization remain challenging. The goal for this study was to investigate whether prostaglandin E2 (PGE2), and specifically its receptors EP2 and/or EP4, attenuate classically activated (i.

Stabilization of Fibronectin by Random Copolymer Brushes Inhibits Macrophage Activation.

We show that protein unfolding on biomaterials may be dramatically reduced via tuning the chemical heterogeneity of the protein-material interface. Specifically, using dynamic single-molecule methods, we confirmed that the transient structure and dynamics of fibronectin (FN) may be mediated through varying the composition of random copolymer brushes. The brushes, which themselves represent an intriguing biomaterial, were composed of oligoethylene glycol and sulfobetaine methacrylate and presumably stabilized FN through partitioning and/or segregation of the copolymers.

Inflammation via myeloid differentiation primary response gene 88 signaling mediates the fibrotic response to implantable synthetic poly(ethylene glycol) hydrogels.

Synthetic hydrogels, such as poly(ethylene glycol) (PEG), are promising for a range of in vivo applications. However, like all non-biological biomaterials, synthetic hydrogels including PEG elicit a foreign body response (FBR). The FBR is thought to be initiated by adsorbed protein that is recognized by and subsequently activates inflammatory cells, notably macrophages, and culminates with fibrotic encapsulation.

The Host Response in Tissue Engineering: Crosstalk Between Immune cells and Cell-laden Scaffolds.

Implantation of cell-laden scaffolds is a promising strategy for regenerating tissue that has been damaged due to injury or disease. However, the act of implantation initiates an acute inflammatory response. If the scaffold is non-biologic (i.

Zwitterionic PEG-PC Hydrogels Modulate the Foreign Body Response in a Modulus-Dependent Manner.

Reducing the foreign body response (FBR) to implanted biomaterials will enhance their performance in tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are increasingly popular for this application due to their low cost, ease of use, and the ability to tune their compliance via molecular weight and cross-linking densities. PEG hydrogels can elicit chronic inflammation in vivo, but recent evidence has suggested that extremely hydrophilic, zwitterionic materials and particles can evade the immune system.

The effects of hydroxyapatite nanoparticles embedded in a MMP-sensitive photoclickable PEG hydrogel on encapsulated MC3T3-E1 pre-osteoblasts.

This study investigated the effects of introducing hydroxyapatite nanoparticles into a matrix metalloproteinase (MMP) sensitive poly(ethylene glycol) (PEG) hydrogel containing cell adhesion peptides of RGD for bone tissue engineering. MC3T3-E1 pre-osteoblasts were encapsulated in the biomimetic PEG hydrogel, which was formed from the photoclick thiol-norbornene reaction system, cultured for up to 28 d in growth medium or osteogenic differentiation medium, and evaluated by cellular morphology and differentiation by alkaline phosphatase (ALP) activity and bone-like extracellular matrix deposition for mineral and collagen. Hydroxyapatite nanoparticles were incorporated during hydrogel formation and cell encapsulation at 0%, 0.

The in vitro effects of macrophages on the osteogenic capabilities of MC3T3-E1 cells encapsulated in a biomimetic poly(ethylene glycol) hydrogel.

Unlabelled: Poly(ethylene glycol) PEG-based hydrogels are promising for cell encapsulation and tissue engineering, but are known to elicit a foreign body response (FBR) in vivo. The goal of this study was to investigate the impact of the FBR, and specifically the presence of inflammatory macrophages, on encapsulated cells and their ability to synthesize new extracellular matrix. This study employed an in vitro co-culture system with murine macrophages and MC3T3-E1 pre-osteoblasts encapsulated in a bone-mimetic hydrogel, which were cultured in transwell inserts, and exposed to an inflammatory stimulant, lipopolysaccharide (LPS).

and Models for Assessing the Host Response to Biomaterials.

The foreign body response (FBR) occurs ubiquitously to essentially all non-biological materials that are implanted into higher organisms. The FBR is characterized by inflammation followed by fibrosis and is mediated largely by macrophages. While many current medical devices tolerate the FBR, the FBR is responsible for many asceptic device failures and is hindering advancements of new devices that rely on device-host communication to function.