High molecular weight chitosan as an additive in the culture of 3T3-L1 fibroblasts. Effects on cell proliferation induced by PDGF.

PEREZ OE; DI SANTO MC; ALAIMO A.

Ciudad Autónoma de Buenos Aires

Simposio; Exploring the Frontiers of Chemistry: Challenges for the 21st Century; 2019

Facultad de Ciencias Exactas y Naturales (FCEN), University of Buenos Aires (Argentina) and the Ben-Gurion of the Negev University (Israel)

Chitosan is a polysaccharide used in nanotechnological applications due to its biocompatibility, biodegradability and its ability to protect and release drugs in a controlled manner. It is well known its capacity to collaborate in wound regeneration. In the medical field, combining chitosan and growth factors promises to normalize and accelerate the healing of complex wounds. Its physicochemical characteristics, in particular its degree of deacetylation and its molecular weight, are determining factors in the effects observed on biological systems. In this work, we study the effect of high molecular weight chitosan (HMWC) added in mouse fibroblast culture media in two aspects: a) its ability to generate changes in cell cycle and proliferation, b) its ability to enhance the effect of Platelet-Derived Growth Factors (PDGF). For this, a 3T3-L1 line was used which responds variably to recombinant PDGF-AA and PDGF-BB(two isoforms of Platelet-Derived Growth Factor) depending on their receptors, which are present on the cell surface for both types of factors. Viability and cell proliferation was analysed by MTT and Crystal violet assays. We evaluated, by means of immunocytochemistry, the expression of the nuclear protein Ki67, which accumulates only in mitotic cells. We also analysed how serum concentration at culture media may influence the in vitro effect of thechitosan application. The HMWC was absolutely innocuous when evaluating cytotoxicity a concentrations as high as 1000 µg/ml. The results show that HMWC, in the absence of fetal bovine serum, does not produce significant changes either in the proliferation or in the increase of nuclear ki67 protein, but notably enhances the effect of PDGF under those same conditions. However, the addition of serum in the culture media (greater than 2.5%) and 50µg/ml of HMWC increase the proliferation and viability of fibroblasts significantly. The potentiating effect of HMWC on PDGF (PDGF-BB in particular) was verified at any serum concentration present in the culture media (0.1, 2.5, 5 and 10%) and to a lesser extent on PDGF-AA.