Inkjet Printing of Silk Fibroin Membranes for Guided Tissue Regeneration

Introduction: Barrier membranes (BM) can be used in dental implantology and periodontal surgery for guided tissue regeneration (GTR). BM exclude fibroblasts from bone defects and thus guide bony regeneration.
Silk has a long medical history and has many ideal properties that may make it an ideal BM for GTR including: biocompatibility, biodegradability and mechanical properties that can be tailored to specific applications. Inkjet printing is well suited for the fabrication of BM since it enables the production of complex precise samples with excellent reproducibility and control over shape, surface topography and gradients. Therefore, inkjet printing may offer the ability to produce complex, patterned BM with specifically tailored surface characteristics

Objectives: To produce BM by reactive inkjet printing of regenerated silk fibroin (SF) and investigate its in vitro cellular interactions

Method: Silk fibroin with a water soluble silk I structure was suspended in deionised water at a concentration of 10mg/mL. A MicroFab inkjet printer was used to print a layer of SF followed by a layer of methanol. Biocompatibility of the membranes was tested by seeding murine fibroblast (L929) cells onto the surface. Proliferation of the cells was monitored through staining and LDH ‘total cell number’ assays. 

Result: SF constructs were successfully produced using inkjet printing. Printing SF followed by methanol converted the silk structure from water soluble silk I to more mechanically stable and water insoluble silk II. Cells were able to adhere and proliferate on the SF film surfaces demonstrating good biocompatibility. 

Conclusion: Inkjet printing  is an alternative manufacturing method for producing BM for GTR applications.  The BM SF films produced in this study  were able to support cell growth.

Acknowledgements: The authors would like to thank Nobel BiocareUK for funding this investigation and Yu Zhang for providing the silk fibroin suspension.