Challenges in the Fabrication of Biodegradable and Implantable Optical Fibers for Biomedical Applications

Abstract

The limited penetration depth of visible light in biological tissues has encouraged researchers to develop novel implantable light-guiding devices. Optical fibers and waveguides that are made from biocompatible and biodegradable materials offer a straightforward but effective approach to overcome this issue. In the last decade, various optically transparent biomaterials, as well as different fabrication techniques, have been investigated for this purpose, and in view of obtaining fully fledged optical fibers. This article reviews the state-of-the-art in the development of biocompatible and biodegradable optical fibers. Whilst several reviews that focus on the chemical properties of the biomaterials from which these optical waveguides can be made have been published, a systematic review about the actual optical fibers made from these materials and the different fabrication processes is not available yet. This prompted us to investigate the essential properties of these biomaterials, in view of fabricating optical fibers, and in particular to look into the issues related to fabrication techniques, and also to discuss the challenges in the use and operation of these optical fibers. We close our review with a summary and an outline of the applications that may benefit from these novel optical waveguides.

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

“…In reality, the most critical factor to consider is the viscosity compatibility of the materials [ 129 ]. Additionally, the materials used for fiber cladding should be thermoplastic and have a high viscosity (10 4 –10 8 Pa·s at drawing temperature) and molar mass (10 4 –10 5 g/mol) [ 56 ] in order to maintain the preform’s complex architecture during the drawing process. Individual components can be manufactured in a variety of ways, depending on the physicochemical properties of the materials and the desired properties of the fabricated preform.…”

“…Casting, a straightforward method for fabricating preforms and optical fibers of any shape [ 56 ], is widely used because it is efficient, universal, low-cost, and simple to operate. As illustrated in Figure 7 a, the process begins with the preparation of the precursor solution, continues with the injection of the solution into molds, shapes the precursor into the fiber, and removes the fiber from the mold.…”

“…(Adapted with permission from ref. [ 56 ]). ( b ) A schematic showing the extrusion-based 3D printing.…”

“…In 2018, Nazempour, R. et al published an overview on the development of bio-compatible and implantable optical fibers and waveguides for biomedicine, which included a good number of examples and illustrations, clear organization, and expression, as well as informative discussion and outlooks [ 55 ]. Gierej, A. et al presented a systematic review of fabrication processes and discussed issues that may influence them, such as biomaterial properties and other considerations [ 56 ].…”

Bioresorbable Photonics: Materials, Devices and Applications

“…Implantable optical waveguides that can transmit light to target tissues or other implanted optical devices have exhibited great potentials for biomedical applications [64][65][66][67][68][69][70]. Traditional optical waveguide has good optical properties, low transmission loss of light and can transmit lights to deep tissues or organs.…”