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Renewable and degradable materials, formed using biopolymers as material precursors, are sought after in pharmaceutical, biomedical, and industrial fields. Silk-based biomaterials, primarily derived from the silk fibroin protein of the Bombyx mori (B. mori) silkworm, have advantageous mechanical properties, biocompatibility, and commercial availability. Recent efforts aim to expand the range of achievable silk-based biomaterial properties via alternative sources of silk proteins with different sequences and structures. These structural distinctions drive differences in physical and chemical properties of silk fibers, primarily due to the varying degree of crystallinity in the polymers. For the development of alternative silk-based materials, silk from Plodia interpunctella (P. interpunctella), a small agricultural pest that infests and damages food products via silk production, is evaluated. Early investigations have highlighted differences between P. interpunctella and B. mori silk fibroin proteins, however P. interpunctella silk still largely lacks characterization and optimization on both the silk fiber and bulk material level. This work evaluates the structural, thermal, mechanical, and cell-material properties of non-degummed and degummed P. interpunctella silk as a raw material for biomaterial fabrication and discusses the benefits and limitations of these proteins as new biopolymers. Observed properties are used to identify links between silk fibroin protein sequence and fiber function in addition to forming hypotheses in how P. interpunctella silk-based biomaterials will perform in comparison to other natural biopolymers. Future work aims to develop methods to process P. interpunctella silk into material formats, utilizing the material characteristics determined here as a baseline for shifts in material performance.
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Silk Fibroin-Sheathed Conducting Polymer Wires as Organic Connectors for Biosensors
Conductive polymers, owing to their tunable mechanical and electrochemical properties, are viable candidates to replace metallic components for the development of biosensors and bioelectronics. However, conducting fibers/wires fabricated from these intrinsically conductive and mechanically flexible polymers are typically produced without protective coatings for physiological environments. Providing sheathed conductive fibers/wires can open numerous opportunities for fully organic biodevices. In this work, we report on a facile method to fabricate core-sheath poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) PEDOT:PSS-silk fibroin conductive wires. The conductive wires are formed through a wet-spinning process, and then coated with an optically transparent, photocrosslinkable silk fibroin sheath for insulation and protection in a facile and scalable process. The sheathed fibers were evaluated for their mechanical and electrical characteristics and overall stability. These wires can serve as flexible connectors to an organic electrode biosensor. The entire, fully organic, biodegradable, and free-standing flexible biosensor demonstrated a high sensitivity and rapid response for the detection of ascorbic acid as a model analyte. The entire system can be proteolytically biodegraded in a few weeks. Such organic systems can therefore provide promising solutions to address challenges in transient devices and environmental sustainability.
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- Award ID(s):
- 1704435
- PAR ID:
- 10171028
- Date Published:
- Journal Name:
- Biosensors
- Volume:
- 9
- Issue:
- 3
- ISSN:
- 2079-6374
- Page Range / eLocation ID:
- 103
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/bios9030103
