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This review article highlights recent advances in designing biomaterials to be interfaced with food and plants, with the goal of enhancing the resilience of the AgroFood infrastructure by boosting crop production, mitigating environmental impact, and reducing losses along the supply chain. Special attention is given to innovations in biomaterial‐based approaches and platforms for 1) seed enhancement through encapsulation, preservation, and controlled release of payloads (e.g., plant growth‐promoting microbes) to the seeds and their rhizosphere; 2) precision delivery of multi‐scale payloads to targeted plant tissues, organelles, and vasculature; 3) edible food coatings that regulate gas exchanges and provide antimicrobial properties to extend the shelf life of perishable food; and 4) food spoilage detection based on different sensor/reporter systems. Within each domain, biomaterials design principles, emerging micro‐/nanofabrication strategies, and the advantages and disadvantages of different delivery/preservation/sensing platforms are introduced and critically discussed. Views of future requirements, aims, and trends are also given based on the opportunities and challenges of applying biomaterials in the AgroFood system.

 

Despite advances in directing the assembly of biomacromolecules into well-defined nanostructures, leveraging pathway complexity of molecular disorder to order transition while bridging materials fabrication from nano- to macroscale remains a challenge. Here, we present templated crystallization of structural proteins to nanofabricate hierarchically structured materials up to centimeter scale, using silk fibroin as an example. The process involves the use of ordered peptide supramolecular assemblies as templates to direct the folding and assembly of silk fibroin into nanofibrillar structures. Silk polymorphs can be engineered by varying the peptide seeds used. Modulation of the relative concentration between silk fibroin and peptide seeds, silk fibroin molecular weight and pH allows control over nanofibrils morphologies and mechanical properties. Finally, facile integration of the bottom-up templated crystallization with emerging top-down techniques enables the generation of macroscopic nanostructured materials with potential applications in information storage/encryption, surface functionalization, and printable three-dimensional constructs of customized architecture and controlled anisotropy.

 

The precise deployment of functional payloads to plant tissues is a new approach to help advance the fundamental understanding of plant biology and accelerate plant engineering. Here, the design of a silk‐based biomaterial is reported to fabricate a microneedle‐like device, dubbed “phytoinjector,” capable of delivering a variety of payloads ranging from small molecules to large proteins into specific loci of various plant tissues. It is shown that phytoinjector can be used to deliver payloads into plant vasculature to study material transport in xylem and phloem and to perform complex biochemical reactions in situ. In another application, it is demonstratedAgrobacterium‐mediated gene transfer to shoot apical meristem (SAM) and leaves at various stages of growth. Tuning of the material composition enables the fabrication of another device, dubbed “phytosampler,” which is used to precisely sample plant sap. The design of plant‐specific biomaterials to fabricate devices for drug deliveryin plantaopens new avenues to enhance plant resistance to biotic and abiotic stresses, provides new tools for diagnostics, and enables new opportunities in plant engineering.

 

Food quality monitoring, particularly, the detection of bacterial pathogens and spoilage throughout the food supply chain, is critical to ensure global food safety and minimize food loss. Incorporating sensors into packaging is promising, but it is challenging to achieve the required sampling volume while using food‐safe sensor materials. Here, by leveraging water‐based processing of silk fibroin, a platform for the detection of pathogenic bacteria in food is realized using a porous silk microneedle array; the microneedle array samples fluid from the interior of the food by capillary action, presenting the fluid to polydiacetylene‐based bioinks printed on the backside of the array. Through the colorimetric response of bioink patterns,Escherichia colicontamination in fish fillets is identified within 16 h of needle injection. This response is distinct from spoilage measured via the increase in sample pH. It is also shown that the microneedles can pierce commercial food packaging, and subsequently sample fluid and present it to the sensor, enabling the adaptation of the technology downstream in food supply chains such as in stores or at home. This study highlights that regenerated structural biopolymers can serve as safe materials for food contact and sensing with robust mechanical properties and tailored chemistry.

 

We report and validate a new computational method to design tetrapeptides that assemble in response to pH stimuli to form beta-sheeted nanoassemblies and hydrogels. 

Nanotubular structures possess remarkable advantages in a broad range of areas, such as catalysis, sensing, microencapsulation, selective mass transport, filtration, and drug delivery. While the fields of carbon nanotubes and nanotubes made of several noncarbon materials (e.g., metals, oxides, semiconductors) have been progressing rapidly, proteinaceous nanotubes remained largely underexplored. Here, by retrofitting a template wetting approach with multiple silk-based suspensions, we present a rapidly scalable and robust technology for fabricating large arrays (e.g., 20 × 20 cm2) of well-aligned 1D nanostructures made of silk proteins. Benefiting from the polymorphic nature of silk, precise control over the size, density, aspect ratio, and morphology (tubes versus pillars) of silk nanostructures is achieved, which then allows for programmable modulation of the end materials’ functions and properties (e.g., hydrophobicity, oleophilicity, and gas permeability). The silk nanotube arrays fabricated present great utility as antifouling coatings against marine algae and in oil extraction from oil–water mixtures. 

PUF tags made from stochastic assembly of silk microparticles provide a unique solution for anticounterfeiting.