Biomimetic protein-based primer coatings for pha-metal adhesion

Overview

This technology offers a sustainable primer coating solution for polyhydroxyalkanoate (PHA) bioplastic films, addressing a key challenge in bonding metals to compostable bioplastics. The coatings are composed of recombinant fusion proteins engineered to self-assemble upon drying or temperature change, forming robust primer layers with dual affinity to both PHA substrates and metal surfaces. Because the proteins are water-based and fully biodegradable, the technology supports sustainable packaging and product manufacturing without introducing persistent synthetic adhesives.

Technical specifications

• Dual-affinity fusion proteins combine a PHA substrate-binding domain (SBD) derived from PHA depolymerase with elastin-like polypeptides (ELP) that self-assemble on metal surfaces
• Modular genetic design allows programmable fusion of multiple protein domains to tune binding strength and coating properties
• Triggered self-assembly occurs through drying or temperature change, enabling integration into roll coating manufacturing workflows
• Water-based formulation eliminates organic solvents and supports environmentally friendly processing
• Validated components: ELP-based coatings have been demonstrated on aluminum, glass, plastics, and metals; SBD sequences have been characterized for PHA binding affinity
• Production method: recombinant proteins expressed and purified in bacterial host systems
• Optimization pathway: computational screening of SBD-ELP variant libraries to identify top-performing candidates

Technology readiness level

The technology is at an early-to-mid development stage. Individual components have been validated: ELP fusion protein coatings have been fabricated on aluminum via drying-triggered assembly, and SBD sequences have been identified and characterized for PHA film binding. The next phase involves designing and screening SBD-ELP fusion protein variants, synthesizing candidates, and validating coating fabrication on PHA films with aluminum attachment measurements. Optimization for roll coating process compatibility and film property characterization remains to be completed. The estimated development timeline is approximately six months, with the research team seeking partnership support for roll coating equipment and film characterization capabilities.