Microfluidic Fabrication of Biomimetic Helical Hydrogel Microfibers for Blood‐Vessel‐on‐a‐Chip Applications

Abstract

Soft tissue injuries (STIs) affect patients of all age groups and represent a common worldwide clinical problem, resulting from conditions including trauma, infection, cancer and burns. Within the spectrum of STIs a mixture of tissues can be injured, ranging from skin to underlying nerves, blood vessels, tendons and cartilaginous tissues. However, significant limitations affect current treatment options and clinical demand for soft tissue and cartilage regenerative therapies continues to rise.Improving the regeneration of soft tissues has therefore become a key area of focus within tissue engineering. As an emerging technology, 3D bioprinting can be used to build complex soft tissue constructs "from the bottom up," by depositing cells, growth factors, extracellular matrices and other biomaterials in a layer-by-layer fashion. In this way, regeneration of cartilage, skin, vasculature, nerves, tendons and other bodily tissues can be performed in a patient specific manner. This review will focus on recent use of 3D bioprinting and other biofabrication strategies in soft tissue repair and regeneration. Biofabrication of a variety of soft tissue types will be reviewed following an overview of available cell sources, bioinks and bioprinting techniques.

A Phase Inversion‐Based Microfluidic Fabrication of Helical Microfibers towards Versatile Artificial Abdominal Skin

“…Thef ormation of helical microfibers may account for "liquid rope-coil effect" proposed by Barnes and Woodcock, [43] where viscous fluids falling onto surfaces under gravity exhibit periodic coiling patterns.I nat wo-phase coaxial microfluidic channel, ap air of viscous and non-viscous liquids is injected as the inner and outer fluid. As in the reported literature, [7,[44][45][46] when the ratio of inner flow rate and outer flow rate increases to acritical value,the viscous inner fluid appears an obvious deformation and forms ac oil possibly accompanied by folding, which is similar to the liquid rope coiling effect in air.Ingeneral, viscous liquid jets perform buckling behavior under the axial compression originated from solvent extraction-introduced phase inversion and unbalanced fluidic friction between two phases. [42] Therefore,t he physicochemical phase inversion process induces the viscosity increase and phase separation of polymer solution, leading to the formation of helical microfibers.I ti sw orth noting that the helical structures of the asprepared microfibers can be precisely controlled by varying the orifice diameters of inner glass capillary tubes (d i )a nd inclination angles (a)o fthe microfluidic chips.…”

Tissue Engineering and Regenerative Medicine: Achievements, Future, and Sustainability in Asia

“…This encapsulated E. coli may be used in biotransformation, bioremediation, biosensing, and artificial cells. Jia et al (2019b) prepared biomimetic cell-laden helical hydrogel microfibers as blood-vessel-on-chip using alginate based on microfluidics methodology. This hollow microfiber had decent perfusability and could generate swirling blood flow to provide a platform for mimicking nature swirling blood flow.…”

Recent Advances in Microfluidic Platforms for Programming Cell‐Based Living Materials

“…Helical cell‐laden microfibers mimicking natural helical blood vessels were reported by Li and co‐workers (Figure 6c). [ 170 ] Typically, single‐layer helical microfibers were prepared in a two‐flow microfluidic chip when the rate of sheath flow was larger than that of the core flow. The amplitudes of helical microfibers were regulated through controlling the viscosity and rates of the sheath flow.…”