Biological activity of electrospun nanofibers on polymer gels

SALMERON-SANCHEZ M; CANTINI M; CORTIZO AM; FERNANDEZ JM,; MOLINUEVO MS; COELHO-SAMPAIO T; GROTH T; GUGUTKOV D; ALTANKOV G

Taller; 2º Taller de Órganos Artificiales, Biomateriales e Ingeniería de Tejidos, OBI 2011; 2012

In the field of bone and cartilage tissue engineering and in the context of the ongoing project between Europe and Latin America (EULANEST 2010) we aimed at preparing biodegradable polymer gels with tuned hydrophilicity on which random and aligned electrospun nanofibers are deposited to provide spatio-temporal cues to the adhering cell population. The study shows the preparation of material systems and the biological assays to assess their initial biocompatibility and biological activity. Gels were obtained from the radical copolymerisation of caprolactone macromonomers able to self-crosslinking and hydrophilic acrylic units of hydroxy ethylacrylate (v/v 70/30). Nanofibres (NFs) are produced via electrospinning and deposited as random mats, or highly aligned nanofibrous structure. Here we report also on the development of a composite FBG/PLA (fibrinogen/poly-L, D-lactic acid) NFs with significantly improved cell recognition properties. Cytotoxic assays were performed by evaluation of NO production, IL-1 and TNF- into the conditioned media of macrophages. Studies showed that not significant release of cytokines or NO was detected in the media of cells growing on gels. The endothelial cells (HUVEC) interacted well with the NFs, representing higher degree of alignment along their orientation. The well developed focal adhesion complexes, actin cytoskeleton and the improved functional parameters of adhering cells, confirm the superior biological performance of the composite of NFs. Current studies are on the way to demonstrate the applicability of our gel-NFs complex for guiding the functional behavior of MSCs (mesenchymal stem cells), including their differentiation potential to bone or cartilage lineages. Our results confirm the absence of cytotoxic effects of the synthesized polymer-gels and NFs. Collectively, our data show that the composite PLA/FBG NFs deposited on PLA based gels combine the good cell recognition properties of FBG with the excellent mechanical properties of PLA, which characterizes them as an advanced bioactive and bioresorbable scaffold for tissue engineering application. Also, the inclusion of FNG in the PLA avoids possible immunological complications, as autologous FNG rich precipitate can be obtained from the same patient.