Integrated dynamic wet spinning of core-sheath hydrogel fibers for optical-to-brain/tissue communications

Abstract

Hydrogel optical light-guides have received substantial interest for applications such as deep-tissue biosensors, optogenetic stimulation and photomedicine due to their biocompatibility, (micro)structure control and tissue-like Young's modulus. However, despite recent developments, the large-scale fabrication with a continuous synthetic methodology, which could produce core-sheath hydrogel fibers with the desired optical and mechanical properties suitable for deep-tissue applications has yet to be achieved. In this study, we report a versatile concept of integrated light-triggered dynamic wet spinning (ILDWS), which capable of continuously producing core-sheath hydrogel optical fibers with tunable fiber diameters, mechanical and optical-propagation properties. Furthermore, this concept also exhibited versatility for various kinds of core-sheath functional fibers. The wet spinning synthetic procedure and fabrication process were optimized with the rational design of the core/sheath material interface compatibility [core = poly(ethylene glycol diacrylate-co-acrylamide); sheath = Ca-alginate], optical transparency, refractive index and spinning solution viscosity. The resulting hydrogel optical fibers exhibited desirable low optical attenuation (0.18 ± 0.01 dB cm−1 with 650 nm laser light), excellent biocompatibility and tissue-like Young's modulus (< 2.60 MPa). The optical-waveguide hydrogel fibers (OWHFs) were successfully employed for deep-tissue cancer therapy and brain optogenetic stimulation, confirming that they could serve as an efficient versatile tool for diverse deep-tissue therapy and brain optogenetic applications.

Biocompatible and Biodegradable Polymer Optical Fiber for Biomedical Application: A Review

“…In theory, spinning is like extrusion in that it utilizes imposed forces to extrude solutions or melts. Several types of spinning have been developed to date, including wet spinning [ 88 , 137 , 138 ], dry spinning [ 139 , 140 , 141 ], electrospinning [ 142 , 143 , 144 ], microfluidic spinning [ 145 ], and dynamic crosslinking spinning [ 146 ]. Below the following sentences, the first three approaches have been thoroughly reviewed.…”

“…A group of researchers recently reported the fabrication of core-sheath optical fibers with exceptional properties using integrated light-triggered dynamic wet spinning (ILDWS) [ 88 ]. p(PEGDA-co-AAm) was chosen as the core material and Ca–alginate as the sheath material in this work based on optical transparency, refractive index, and solution viscosity.…”

“…Researchers have developed hydrogel optical fibers with increased flexibility, lower propagation loss, a longer function period, and a more controllable degradation rate [ 50 , 85 , 87 ]. These fibers can be used widely as drug and cell carriers [ 88 ], glucose and blood oxygenation level sensors [ 46 , 85 , 89 ], and light delivery, introducing optogenetics therapies, minimally invasive surgery, and photomedicine [ 45 , 46 , 62 , 90 ] one step closer to clinical practice.…”

Rational Design and Preparation of Functional Hydrogels for Skin Wound Healing

“…Compared with traditional hydrogels, hydrogel fibers have a 3D network structure with a higher specific surface area, which can simulate the structure and characteristics of the ECM and provide more sites for cell adhesion, migration, and proliferation ( Li et al, 2021 ). The standard preparation methods of hydrogel fibers include electrospinning ( Liu W. et al, 2020 ), 3D printing ( Kong et al, 2020 ), microfluidic spinning ( Cai et al, 2019 ), and dynamic polymer spinning ( Chen et al, 2020 ). The most commonly used method is to prepare nanofibers by electrospinning and then cross-link the obtained fibrous membrane to improve its mechanical properties.…”

Fiber‐Shaped Electronic Devices

“…Moreover, fiber‐shaped electronic devices with shape‐memory and self‐healing ability and those with a possibility to be monolithically integrated with complementary devices have also been reported. [ 1,4–6 ] These are energy harvesting devices such as solar cells, piezoelectric and triboelectric nanogenerators (NGs), [ 7,8 ] energy storage devices (ESDs) including supercapacitors (SCs), and various types of batteries, [ 9,10 ] light‐emitting devices, [ 11 ] and sensors, used in medical devices [ 12 ] and diagnostics, civil engineering, and fitness. [ 13,14 ]…”