• regenerative medicine;
  • microscale engineering;
  • functionalization;
  • microparticles;
  • platelet lysates

The development of biologically instructive biomaterials with application for tissue regeneration has become the focus of intense research over the last years. This work reports a novel approach for the production of three-dimensional constructs for tissue engineering applications based on the assembly of chitosan microparticles exhibiting specific biological response with cells. Chitosan microparticles with a size range between 20 and 70 μm are functionalized with platelet derived growth factor (PDFG-BB). The functionalization is achieved by previous immobilization of an anti-PDGF-BB antibody, using a water-soluble carbodiimide. When incubated with a cocktail of growth factors-platelet lysates, the previously functionalized particles are able to target PDGF-BB from the protein mixture. In vitro studies are carried out focusing on the ability of these systems to promote the assembly into a stable 3D construct triggered by the presence of human adipose stem cells, which act as crosslinker agents and induce the formation of a hydrogel network. The presence of immobilized growth factors gives to this system a biological functionality towards control on cell function. It is also bioresponsive, as cells drive the assembly process of the microgel. These versatile biomimetic microgels may provide a powerful tool to be used as an injectable system for non-invasive tissue engineering applications with additional control over cellular function by creating specific microenvironments for cell growth.