Biocompatible, Tunable, Multifunctional Adhesive Silk-PDA Composite Films for Modern Labeling Needs

Adhesive labels are massively used in production processes and are ubiquitously present in nearly every product. However, their use often complicates the recycling of the materials they are applied to or leads to fragmentation, dispersing microplastics into the environment. We present here biopolymer-based adhesive films suitable for labeling applications by leveraging silk polymorphism in combination with mussel-inspired chemistry. Incorporating dopamine into the polymeric matrix introduces water-triggered adhesive properties and a plasticizing effect. Its utility can be further augmented through the addition of glycerol, which enables the formation of flexible and insoluble adhesive films. The versatility of form and function of the base biomaterial allows reshaping of protein films on demand and to create functional adhesive surfaces with tunable properties, opening possibilities for programmable biomaterial-based interfaces, that can be used either as laminates on a variety of different substrates or as standalone labels. Adhesive strength, preferred breakage interface, and degradation rates in water can all be customized to meet specific requirements underscoring the versatility and applicability of the platform.