Descrição
Chitosan blends with synthetic biodegradable polymers have been proposed for various biomedical applications
due to their versatile mechanical properties and easier processing. However, details regarding the main surface
characteristics that may benefit from the blending of these two types of materials are still missing. Hence, this
work aims at investigating the surface properties of chitosan-based blends, illustrating the way these properties
determine the material-proteins interactions and ultimately the behavior of osteoblast-like cells. The surface
characteristics of modified and nonmodified blends were assessed using complimentary techniques such as optical
microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR-ATR), X-ray
photoelectron spectroscopy (XPS), contact angle measurements and surface energy calculations. The adsorption
of human serum albumin (HSA) and human plasma fibronectin (HFN) onto the different surfaces was quantified
by association of an indirect method with a colorimetric assay. It was found that the presence of chitosan on the
surface promoted the adsorption of proteins. Moreover, a preferential adsorption of albumin over fibronectin was
registered. The in vitro biological performance of the studied materials was further investigated by a direct contact
assay with an osteoblastic-like cell line (SaOs-2). A synergistic effect of the two components of the blend was
observed. While the synthetic polyester promoted the adhesion of SaOs-2, the presence of chitosan significantly
enhanced the osteoblastic activity of these cells. This work further confirmed the interest in designing polymeric
blends with natural polymers as a successful strategy to enhance the biological performance of a biomaterial.
; Pashkuleva, I. 
