3D Printing and Nanofabrication of Multifunctional Scaffold Materials for Biomedical Applications

Millions of musculoskeletal tissue graft procedures are performed worldwide on an annual basis to treat traumatic injuries, degenerative diseases, and tumour resections. Tissue harvested from the patient (autogenic) are the preferred tissue grafting materials, despite drawbacks and potential complications, because engineered materials have been unable to meet the diverse range of multifunctional requirements, which includes biocompatibility, biodegradation, mechanical properties, and porous structure.
Nanofabrication techniques enable material systems composed of precise combinations of nano-scale building blocks, including individual molecules and nano-particles. These techniques have been utilised to produce nano-structured material systems with a range of unique properties and functions, including high strength and stiffness, biocompatibility, biodegradability, and delivery/release of therapeutic drugs. Combining nanofabrication with 3D-printing allows control over micro-scale porous structure, in addition to nano-scale control over structure and composition, and helps scale-up nano-scale processes for the production of macro-scale bulk materials. Nanofabrication of polymer-clay nanocomposites onto porous open-cell foams has enabled the production of macro-scale nanocomposite porous materials with controlled stiffness and porosity spanning remarkable ranges from those of soft elastomer foams to very stiff, lightweight honeycomb and lattice materials [1]. Tailoring the material composition at the surface has enhanced the biocompatibility of these materials for application as engineered tissue scaffold materials [2]. Further work is needed to combine controlled mechanical properties, porosity, and biocompatibility with additional functionalization including biodegradability, and therapeutic drug-delivery. Achieving these properties and functionalities will help address the major unmet need for engineered tissue scaffold materials as replacements for existing treatment strategies using autogenous grafts, which are limited in supply and efficacy.
Nanocomposite thin-films will be produced using an aqueous-based nanofabrication technique. Material systems targeting load-bearing functionality will be mechanically characterized, while materials targeting biodegradability will be characterized in terms of in vitro degradation. Hybrid material systems combining load-bearing and biodegradable functionalities will be designed and characterized as functions of varying composition and nano-structure. Porous nanocomposites will be produced via nanofabrication onto 3D-printed scaffolds with controlled initial pore structure. The porous structure, mechanical properties, and degradation characteristics of porous nanocomposites will be assessed against requirements for engineered musculoskeletal tissue scaffolds. The integration of material systems for therapeutic drug-delivery and enhanced biocompatibility will also be explored via local and international collaborations with biomedical researchers.