Reactive inkjet printing of regenerated silk fibroin films for use as dental barrier membranes

Current commercially available barrier membranes for oral surgery have yet to achieve a perfect design. Existing materials used are either non-resorbable and require a second surgery for their extraction, or alternatively are resorbable but suffer from poor structural integrity or degrade into acidic by-products. Silk has the potential to overcome these issues and has yet to be made into a commercially available dental barrier membrane. Reactive inkjet printing (RIJ) has recently been demonstrated to be a suitable method for assembling silk in its regenerated silk fibroin (RSF) form into different constructs. This paper will establish the properties of RSF solutions for RIJ and the suitability of RIJ for the construction of RSF barrier membranes. Printed RSF films were characterised by their crystallinity and surface properties, which were shown to be controllable via RIJ. RSF films degraded in either phosphate buffered saline or protease XIV solutions had degradation rates related to RSF crystallinity. RSF films were also printed with the inclusion of nano-hydroxyapatite (nHA). As reactive inkjet printing could control RSF crystallinity and hence its degradation rate, as well as offering the ability to incorporate bioactive nHA inclusions, reactive inkjet printing is deemed a suitable alternative method for RSF processing and the production of dental barrier membranes.