Extending BigSMILES to non-covalent bonds in supramolecular polymer assemblies.

As a machine-recognizable representation of polymer connectivity, BigSMILES line notation extends SMILES from deterministic to stochastic structures. The same framework that allows BigSMILES to accommodate stochastic covalent connectivity can be extended to non-covalent bonds, enhancing its value for polymers, supramolecular materials, and colloidal chemistry. Non-covalent bonds are captured through the inclusion of annotations to pseudo atoms serving as complementary binding pairs, minimal key/value pairs to elaborate other relevant attributes, and indexes to specify the pairing among potential donors and acceptors or bond delocalization.

Methacrylated Bovine Serum Albumin and Tannic Acid Composite Materials for Three-Dimensional Printing Tough and Mechanically Functional Parts.

Nature uses proteins as building blocks to create three-dimensional (3D) structural components (like spiderwebs and tissue) that are recycled within a closed loop. Furthermore, it is difficult to replicate the mechanical properties of these 3D architectures within synthetic systems. In the absence of biological machinery, protein-based materials can be difficult to process and can have a limited range of mechanical properties.

Photocross-Linked Antimicrobial Amino-Siloxane Elastomers.

Mechanically robust bulk antimicrobial polymers are one way to address disease transmission via contaminated surfaces. Here, we demonstrate the visible light photo-oxidative cross-linking of amine-containing PDMS using a single-component, solvent-free system where amines have a dual role as antimicrobial functionalities and cross-linking sites. Rose Bengal, a xanthene dye used as a fluorescent stain, is thermally reacted with the polymer to give a solvent-free liquid siloxane that can generate reactive singlet oxygen upon aerobic green light irradiation, coupling the amine functionalities into imine cross-links.

Additive Manufacturing of Bovine Serum Albumin-Based Hydrogels and Bioplastics.

Biosourced and biodegradable polymers for additive manufacturing could enable the rapid fabrication of parts for a broad spectrum of applications ranging from healthcare to aerospace. However, a limited number of these materials are suitable for vat photopolymerization processes. Herein, we report a two-step additive manufacturing process to fabricate robust protein-based constructs using a commercially available laser-based stereolithography printer.

3D printed coaxial nozzles for the extrusion of hydrogel tubes toward modeling vascular endothelium.

Engineered tubular constructs made from soft biomaterials are employed in a myriad of applications in biomedical science. Potential uses of these constructs range from vascular grafts to conduits for enabling perfusion of engineered tissues and organs. The fabrication of standalone tubes or complex perfusable constructs from biofunctional materials, including hydrogels, via rapid and readily accessible routes is desirable.