No abstract

The effects of indazolium trans-[tetrachlorobis(1H-indazole)ruthenate(III)] (KP1019, or FFC14A), the second ruthenium compound that entered clinical trials, in an in vitro model of tumour invasion and metastasis show that the antitumour effects of this compound might include also the modulation of cell behaviour although its cytotoxicity appears to be predominant over these effects. The comparison with its imidazole analogue KP418 shows however its superiority, being able to control in vitro cell growth and in some instances also in vivo tumour development. These results suggest that the activity of KP1019 is predominantly due to direct cytotoxic effects for tumour cells, evident also in vivo on primary tumour growth and that the effects on modulation of the biological behaviour of the cancer cell can be present but might have only a partial role.

Regenerative medicine is continuously facing new challenges and it is searching for new biocompatible, green/natural polymer materials, possibly biodegradable and non-immunogenic. Moreover, the critical importance of the nano/microstructuring of surfaces is overall accepted for their full biocompatibility and in vitro/in vivo performances. Chitosan is emerging as a promising biopolymer for tissue engineering and its application can be further improved by exploiting its nano/microstructuration. Here, we report the state of the art of chitosan films and scaffolds nano/micro-structuration. We show that it is possible to obtain, by solvent casting, chitosan thin films with good mechanical properties and to structure them at the microscale and even nanoscale level, with resolutions down to 100 nm.

Peripheral nerve injuries are a common condition in which a nerve is damaged, affecting more than one million people every year. There are still no efficient therapeutic treatments for these injuries. Artificial scaffolds can offer new opportunities for nerve regeneration applications; in this framework, chitosan is emerging as a promising biomaterial. Here, we set up a simple and effective method for the production of micro-structured chitosan films by solvent casting, with high fidelity in the micro-pattern reproducibility. Three types of chitosan directional micro-grooved patterns, presenting different levels of symmetricity, were developed for application in nerve regenerative medicine: gratings (GR), isosceles triangles (ISO) and scalene triangles (SCA). The directional patterns were tested with a Schwann cell line. The most asymmetric topography (SCA), although it polarized the cell shaping less efficiently, promoted higher cell proliferation and a faster cell migration, both individually and collectively, with a higher directional persistence of motion. Overall, the use of micro-structured asymmetrical directional topographies may be exploited to enhance the nerve regeneration process mediated by chitosan scaffolds.