Functionalized Microparticles Producing Scaffolds in Combination with Cells

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.