Protein Bricks: 2D and 3D Bio‐Nanostructures with Shape and Function on Demand

Date:18-05-2018   |   【Print】 【close

Precise patterning of polymer-based biomaterials for functional bionanostructures has widespread applications such as biosensing and biomimetics, where fine structural control and appropriate functionalization are essential. Since most biological molecules are fragile and only functional in aqueous environments, there are severe constraints on the integration of the molecules into the conventional fabrication technologies. And most methods only yield 2D and pseudo-3D structures with restricted geometries and functionalities.

Recently, Tiger H. Tao and co-workers reported a new method of building arbitrary grayscale and 3D building blocks with both shape and function on demand via Protein Bricks by precisely patterning on genetically engineered spider silk, termed “Protein Bricks”.

Spider silks have unique mechanical strength and extensibility, in addition to their outstanding biocompatibility. The added control over protein sequence and molecular weight of recombinant spider silk via genetic engineering provides unprecedented lithographic resolution, sharpness and biological functions compared to natural proteins. And the real beauty of this material lies in the combination of multi-level modification and multi-scale manufacturing. The ease of functionalization through simple mixing with organic and inorganic dopants in the water-based solution, bringing function to programmable nanoscale forms.

The 3D assembly is realized by a combination of ion beam lithography (IBL) and electron beam lithography (EBL) steps in a programmable sequence with precise alignment. This approach can break the resolution limit of protein patterning previously achieved in silk and in biopolymers in general, and achieve unprecedented structural complexity. This multiplex of functionality in addition to on-demand nanoscale composite structures adds an entirely new dimension to the versatility of this platform. Compared with traditional nanofabrication technology, this approach provides a facile method for excellent biocompatibility, ease of functionalization, heterogeneous nanostructuring and controllable 3D assembly, which sheds light on a wide range of applications such as biosensing for structure enhanced fluorescence and biomimetic microenvironments for controlling cell fate.

The team put forward a very simplified example of the Protein Bricks concept using spider silk and IBL method. However, a wide range of materials, functional components and fabrication methods can be used in this method. The protein bricks will serve as an important tool for biomimetics, biophotonics and so on.

The work was published in Advanced Materials as an inside back cover story.