Flexible biodegradable citrate-based polymeric step-index optical fiber

Abstract

Implanting fiber optical waveguides into tissue or organs for light delivery and collection is among the most effective ways to overcome the issue of tissue turbidity, a long-standing obstacle for biomedical optical technologies. Here, we report a citrate-based material platform with engineerable opto-mechano-biological properties and demonstrate a new type of biodegradable, biocompatible, and low-loss step-index optical fiber for organ-scale light delivery and collection. By leveraging the rich designability and processibility of citrate-based biodegradable polymers, two exemplary biodegradable elastomers with a fine refractive index difference and yet matched mechanical properties and biodegradation profiles were developed. Furthermore, we developed a two-step fabrication method to fabricate flexible and low-loss (0.4 db/cm) optical fibers, and performed systematic characterizations to study optical, spectroscopic, mechanical, and biodegradable properties. In addition, we demonstrated the proof of concept of image transmission through the citrate-based polymeric optical fibers and conducted in vivo deep tissue light delivery and fluorescence sensing in a Sprague-Dawley (SD) rat, laying the groundwork for realizing future implantable devices for long-term implantation where deep-tissue light delivery, sensing and imaging are desired, such as cell, tissue, and scaffold imaging in regenerative medicine and in vivo optogenetic stimulation.

Functionalized Flexible Soft Polymer Optical Fibers for Laser Photomedicine

“…As the fabricated SPOFs can be made to fit to the needle for implantation, polymer optical fibers with much smaller diameters can be potentially fabricated by using customized molds, injection, electrospinning, microfluidics, and 3D printing techniques . The utilization of biodegradable and bioresorbable materials as the optical fiber matrix in implantation can prevent damaging living tissue during fiber retraction during surgery . Encapsulating drug‐loading nanocarriers and therapeutic cells within the SPOF can allow targeted drug release in vivo .…”

Recent Advances in Bioplastics: Application and Biodegradation

“…In fact, the photonic-driven technology, in the therapeutic space, can be considered as a bridge between a DDS (specifically photo-responsive) and implantable devices for tissue engineering [132]. Shan and co-workers [133] used a citrate-based polymer as a biodegradable and implantable optical fibre with minimal loss in refractive index. As a proof of concept, both fluorescence emission via light induction and image transmission via optical fibres were successfully achieved in a rat model.…”

Citrate chemistry and biology for biomaterials design

“…Both POC and POMC also show low absorption which enables organ scale light delivery and collection. Therefore, by leveraging the processibility of the two polymers, a biodegradable, flexible, step-index and low-loss optical fibers consisting of a POC cladding and a POMC core has been fabricated for potential deeptissue light delivery, sensing and imaging applications [22]. Addition of vinyl moieties into water soluble CBBs has endowed the polymer, poly(ethylene glycol) maleate citrate (PEGMC), with injectablity and in situ cross-linking capability when combined with crosslinker and initiator, thus providing advantages including minimally invasive injection, conformation to the wound shape and localized drug or cell delivery [17].…”