Atmospheric Pressure Non-Equilibrium Plasma as a Green Tool to Crosslink Gelatin Nanofibers.

Anna Liguori,Matteo Gherardi,Chiara Gualandi,Maria Chiara Oleari,Adriana Bigi,Silvia Panzavolta,Maria Letizia Focarete,Vittorio Colombo

doi:10.1038/srep38542

Abstract

Electrospun gelatin nanofibers attract great interest as a natural biomaterial for cartilage and tendon repair despite their high solubility in aqueous solution, which makes them also difficult to crosslink by means of chemical agents. In this work, we explore the efficiency of non-equilibrium atmospheric pressure plasma in stabilizing gelatin nanofibers. We demonstrate that plasma represents an innovative, easy and environmentally friendly approach to successfully crosslink gelatin electrospun mats directly in the solid state. Plasma treated gelatin mats display increased structural stability and excellent retention of fibrous morphology after immersion in aqueous solution. This method can be successfully applied to induce crosslinking both in pure gelatin and genipin-containing gelatin electrospun nanofibers, the latter requiring an even shorter plasma exposure time. A complete characterization of the crosslinked nanofibres, including mechanical properties, morphological observations, stability in physiological solution and structural modifications, has been carried out in order to get insights on the occurring reactions triggered by plasma.

Highlights

Gelatin can be obtained from partial hydrolysis of native collagen, which represents the most abundant structural protein of animal tissues[1]
Since gelatin is highly soluble in aqueous solution, several applications require its crosslinking in order to confer water stability and prevent solubilization
Electrospun pure gelatin (G) and genipin-containing gelatin mats (GG) were crosslinked directly in the solid state, by means of an innovative, environmentally friendly and easy to use method, consisting in exposing mats to an atmospheric pressure non-equilibrium plasma treatment[21], and in rinsing them in aqueous solution to stabilize the crosslinking reactions triggered by plasma onto the fibers surface

Summary

Introduction

Gelatin can be obtained from partial hydrolysis of native collagen, which represents the most abundant structural protein of animal tissues[1]. To the best of our knowledge, only few studies report the use of low pressure plasma to confer water resistance and improve the mechanical properties of gelatin directly in the solid state[19,20]. These studies, carried out on electrospun gelatin fibers, put into evidence that low pressure plasma treatments were not successful in stabilizing gelatin against water solubilization. The Authors pointed out that, despite no visible alteration of fibers morphology was detected after the plasma exposure, the crosslinking degree turned out to be rather low, since the scaffold degraded after only a few hours of immersion in buffer solution at 37 °C

Methods

Results

Conclusion