Cell-adhesion ligands

Good transport of nutrient to cells and products from cells Can be easily modified with cell adhesion ligands Can be injected in vivo as a liquid that gets at body temperature Usually biocompatible Disadvantages Can be hard to handle... 

In the context of this book, the term bioactivity is mainly applied to polymers that incorporate elements capable of molecular biological recognition, such as peptide sequences serving as cell adhesion ligands and polyanionic sites that utilize electrostatic interactions for the biomimetic presentation of... 

Kong, H.J., Hsiong, S., Mooney, D.J. Nanoscale cell adhesion ligand presentation regulates nonviral gene delivery and expression. Nano Letters 7,161-166 (2007)... 

Figure 4.2 Self-assembling peptide amphiphiles (PA) used for biomimetic mineralization of HA/PA nanocomposite, (a) Chemical structure of the PA, comprising 5 regions (1) a hydrophobic alkyl tail (2) four cysteine residues that can form disulfide bonds to polymerize the self-assembled structure (3) a flexible linker region of three glycine residues (4) a single phosphorylated serine residue that was able to interact strongly with calcium ions and help direct mineralization of HA (5) the cell adhesion ligand ROD. (b) Molecular model of one single PA molecule, (c) Schematic showing the self-assembly of PA molecules into a cylindrical micelle.

On the photoactivatable substrates discussed so far, the cells adhere to the photoirradiated regions via the interaction with proteins physically adsorbed onto the surface after photoirradiation. These proteins originally existed in the culture medium, but we are not able to specify which proteins mediate cell adhesion. This fact obscures the molecular level discussion of the signaling originated from the cell-substrate interactions. To tackle this issue, we have developed two new photoactivatable substrates, where the photoexposed surface presents molecularly controlled cell-adhesive ligand. 

The conformation of the fibronectin blocks was not determined from these analyses. Since the fibronectin blocks are located between SLP block domains in the sequence of ProNectin F, it must be presumed that they occur at the turns between the crystallized SLP blocks. Their conformation is probably variable, but the fact that they are highly active as cell adhesion ligands, indicates that at least some of them are accessible and are exposed at the exterior of the crystalline region of the tUes . 

The first active peptides inserted into the polymer chain were the well-known, general-purpose cell-adhesion peptides RGD (R = L-arginine, D = L-aspartic acid) and REDV (E = L-glutamic acid), which are specific for endothelial cells. The incorporation of these active peptides as cell-adhesion ligands resulted in a high capacity to promote cell attachment that was not shown by the simple... 

Easy to mold and modify the SEirface with cell adhesion ligands Increased patient compliance ... 

---