Synthetic-based Hydrogels

The degradation profile of PEG hydrogels can be controlled by the addition of degradable linkages such as poly(a-hydroxy esters) or peptides that can be 

Alginate gels Murine embryonic stem cells 138 

Alginate/chitosan capsules Human osteoprogenitor cells (STRO-l ) 139 

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There is a growing interest in peptide-based hydrogels for drug delivery systems because synthetic polymers are combined with protein domains that self-assemble through hydrophobic coiled-coil interactions and the self-assembly occurs in response to temperature and pH. ... 

Fig. 1 Supramolecular systems described in this chapter. Top-. The extracellular matrix inspires most of the work and consists of fibers to resist tensile stresses such as collagens, fibers to resist compressive stresses such as the glycosaminoglycans, and soluble factors for cell signalling. Bottom Natural systems such as collagen, coiled-coil structures, p-sheet peptides such as peptide amphiphiles and multidomain peptides, hybrid systems such as streptavadin-biotin cross-linked microparticles, and synthetic systems such as the UPy-based hydrogelators...

Physically crosslinked PNIPAM-based hydrogels were described for the first time by Han et al [51], who synthesized poly(N-isopropylacrylamide-co-acrylic acid) (p(NIPAM-co-AA)) to prepare thermosensitive matrices that were used in follow-up studies for biomedical purposes, particularly as synthetic matrices in refillable bio-artifidal pancreas. Encapsulated Langeran islets showed good viability, and the cellladen artificial matrices showed insulin release [52,53]. Similarly and more recently, p(NIPAM) networks were crosslinked using N, N -methylenebisacrylamide (BIS) and used for bovine serum albumin (BSA) release studies in vitro. The release of the protein... 

Park, Y, Lutolf, M.P., HubbeU, J.A. et al. 2004. Bovine primary chondrocyte culture in synthetic matrix metaUoproteinase-sensitive poly(ethylene glycol)-based hydrogels as a scaffold for cartilage repair. Tissue Eng 10(3-4) 515-22. 

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