Microencapsulation of High-Content Actives Using Biodegradable Silk Materials.
Muchun LiuPierre-Eric MillardHenning UrchOphelie ZeyonsDouglas FindleyRupert KonradiBenedetto MarelliPublished in: Small (Weinheim an der Bergstrasse, Germany) (2022)
There is a compelling need across several industries to substitute non-degradable, intentionally added microplastics with biodegradable alternatives. Nonetheless, stringent performance criteria in actives' controlled release and manufacturing at scale of emerging materials hinder the replacement of polymers used for microplastics fabrication with circular ones. Here, the authors demonstrate that active microencapsulation in a structural protein such as silk fibroin can be achieved by modulating protein protonation and chain relaxation at the point of material assembly. Silk fibroin micelles' size is tuned from several to hundreds of nanometers, enabling the manufacturing-by retrofitting spray drying and spray freeze drying techniques-of microcapsules with tunable morphology and structure, that is, hollow-spongy, hollow-smooth, hollow crumpled matrices, and hollow crumpled multi-domain. Microcapsules degradation kinetics and sustained release of soluble and insoluble payloads typically used in cosmetic and agriculture applications are controlled by modulating fibroin's beta-sheet content from 20% to near 40%. Ultraviolet-visible studies indicate that burst release of a commonly used herbicide (i.e., saflufenacil) significantly decreases from 25% to 0.8% via silk fibroin microencapsulation. As a proof-of-concept for agrochemicals applications, a 6-day greenhouse trial demonstrates that saflufenacil delivered on corn plants via silk microcapsules reduces crop injury when compared to the non-encapsulated version.
Keyphrases
- tissue engineering
- drug delivery
- molecularly imprinted
- climate change
- metal organic framework
- wound healing
- clinical trial
- study protocol
- human health
- amino acid
- randomized controlled trial
- cancer therapy
- binding protein
- phase iii
- highly efficient
- mass spectrometry
- small molecule
- single molecule
- risk assessment
- anaerobic digestion
- life cycle