Figure 4.

Strategies to incorporate and to promote the release of bio-active agents from biomaterial scaffolds. (A) Physical immobilization of bio-active agents leads to uncontrolled and rapid drug delivery kinetics. (B) Simultaneous or (C) sequential presentation of bio-active agents encapsulated into micro-and nanoparticles incorporated into scaffolds. (D) Bio-active agents or particulate carriers can be covalently bound to the scaffolds, resulting in a more controlled release mechanism. (E) Nanoparticles incorporated inside microparticles within the scaffold, promoting multiple release systems with distinct delivery rates. Adapted from Santo et al. (2012a). [Colour figure can be viewed at wileyonlinelibrary.com]