Figure 1.
(a) PEG chains are represented by lines proportional in length to the molecular weight. (b) Chemical drawing of eight and four-arm PEG molecular cores and of an arm modified with alendronate. (c) Schematic representation of P(8)20-AA and P(8)10-AA solutions. The density of lines is constant, and depicts a polymer concentration where P(8)20-AA macromers overlap in solution. At the same concentration, P(8)10-AA molecules cannot fill the entire space and do not form a transient network. (d) Transient network showing free ends, intramolecular (loops) and intermolecular (crosslinks) associations. Calcium ions and alendronate moieties are represented by red dots and blue half-rings, respectively.