Cost and Time Effective Lithography of Reusable Millimeter Size Bone Tissue Replicas With Sub-15 nm Feature Size on A Biocompatible Polymer

The ability to replicate the microenvironment of biological tissues creates unique biomedical possibilities for stem cell applications. Current fabrication methods are limited by either the control on feature size and shape, or by the throughput and size of the replicas. Here, a novel platform is reported that combines thermal scanning probe lithography (tSPL) with innovative methodologies for the low-cost and high-throughput nanofabrication of large area quasi-3D bone tissue replicas with high fidelity, sub-15 nm lateral precision, and sub-2 nm vertical resolution. This bio-tSPL platform features a biocompatible polymer resist that withstands multiple cell culture cycles, allowing the reuse of the replicas, further decreasing costs and fabrication times. The as-fabricated replicas support the culture and proliferation of human induced mesenchymal stem cells, which display broad therapeutic and biomedical potential. Furthermore, it is demonstrated that bio-tSPL can be used to nanopattern the bone tissue replicas with amine groups, for subsequent tissue-mimetic biofunctionalization. The achieved level of time and cost-effectiveness, as well as the cell compatibility of the replicas, make bio-tSPL a promising platform for the production of tissue-mimetic replicas to study stem cell-tissue microenvironment interactions, test drugs, and ultimately harness the regenerative capacity of stem cells and tissues for biomedical applications.