Project

Hybrid Living Fibers

The Mediated Matter Group

In concert with the Mediated Matter group's HLM additive manufacturing research, the emergent field of Hybrid Living Fibers (HLF) or "biohybrid" fiber systems has derived novel techniques to encapsulate or adsorb living and bio-active agents within fiber-based constructs. The aim of these composites is to: (I) leverage fiber structures to benefit the survivability of biological agents, and (II) augment fibers with the functional properties of living systems (e.g. protein expression, material production, detection or digestion of pathogenic particles).

Further, HLF constructs are capable of being organized into sophisticated and hierarchical higher-order structures (e.g., helical twists, braids, knits, weaves).

The initial fibers investigated were spun from a dope comprising primarily of sodium alginate—a polysaccharide known for its versatile and non-toxic hydrogel properties, widely used by health and food industries (e.g., for wound dressing, drug delivery, food texture and packaging).

It is possible to make robust alginate fibers through a process of wet spinning and drawing. Such fibers are currently being developed as biomaterial substitutes in the textile and fashion industry. In this work, we explore the encapsulation living cells within a wet-spun alginate fiber, as a functional material format for supporting bio-engineered and biosynthesized outputs.

Our HLF production process utilizes a custom-built wet-spinning platform, consisting of an extrusion needle extending from a syringe pump and a rotary bath. Fiber properties (diameter, strength, alignment, surface texture) are contingent on needle diameter and shear force generated by the difference in receiving plate and flow velocity. Fibers containing live cells, stored in H2O, maintain bacterial activity for 1-2 weeks.

Protein expression in wet-spun fibers was fist validated with engineered E. coli containing plasmids for the inducer-gated synthesis of green fluorescent protein (GFP), responding to the presence of different chemical signals. We have since demonstrated the ability for these fibers to synthesize colored dyes in situ, in monofilament and woven textile formats.

Weaving brought together both ancient and new practices in the Wet Lab Atelier. In this hybrid process, initially colorless fabric swatches made up of bacterial fibers were able to produce color compounds that could permanently dye both warp and weave.

The present goals of our HLF platform include:

Cell-Fiber Incorporation. Use of a wet-spinning technique to produce tunable, meter-length biohybrid fibers with viable cells.

Protein Expression from Fibers. Demonstration that fibers can express bio-active compounds via the incorporated cells or biological systems.

Creation of Secondary Structures. Translation of fibers into industrial spinning, weaving, or knitting processes as an approach for utilizing textile patterning methodologies for fiber templating and producing bio-composite textiles across scales.

Strategies for Cell Survival. Expansion of the types of living systems compatible with this fiber method, to increase prolonged cell survival and match material properties to inherent or engineered cell properties.

This work was honored as a Best Poster Award Winner at the 2019 Fall Materials Research Society (MRS) meeting. Research of HLF production is ongoing.