Autofluorescence properties of balloon polymers used in medical applications

Abstract

Significance: For use in medical balloons and related clinical applications, polymers are usually designed for transparency under illumination with white-light sources. However, when illuminated with ultraviolet (UV) or blue light, most of these materials autofluoresce in the visible range, which can be a concern for modalities that rely on tissue autofluorescence for diagnostic or therapeutic purposes. Aim: A search for published information on spectral properties of polymers that can be used for medical balloon manufacturing revealed a scarcity of published information on this subject. The aim of these studies was to address this gap. Approach: The autofluorescence properties of polymers used in medical balloon manufacturing were examined for their suitability for hyperspectral imaging and related applications. Excitation-emission matrices of different balloon materials were acquired within the 320-to 620-nm spectral range. In parallel, autofluorescence profiles from the 420-to 620-nm range were extracted from hyperspectral datasets of the same samples illuminated with UV light. The list of tested polymers included polyurethanes, nylon, polyethylene terephthalate (PET), polyether block amide (PEBAX), vulcanized silicone, thermoplastic elastomers with and without talc, and cyclic olefin copolymers, known by their trade name TOPAS. Results: Each type of polymer exhibited a specific pattern of autofluorescence. Polyurethanes, PET, and thermoplastic elastomers containing talc had the highest autofluorescence values, while sheets made of nylon, PEBAX, and TOPAS exhibited negligible autofluorescence. Hyperspectral imaging was used to illustrate how the choice of specific balloon material can impact the ability of principal component analysis to reveal the ablated cardiac tissue. Conclusions: The data revealed significant differences between autofluorescence profiles of the polymers and pointed to the most promising balloon materials for clinical implementation of approaches that depend on tissue autofluorescence.

Three-Dimensional Printer-Assisted Electrospinning for Fabricating Intricate Biological Tissue Mimics

“…The high autofluorescence from thermoplastic PU posed challenges for fluorescence imaging. This can be considered as a limitation of the specific PU used and suggests the need for a more suitable polymer [31]. Beyond changing the polymer, alternative imaging techniques might be used, such as using molecular probes or reporter-labeled fluorescent cell lines [32,33].…”

Merging holography, fluorescence, and machine learning for in situ, continuous characterization and classification of airborne microplastics

“…Polymers have been known to have autofluorescent properties, but these properties may complicate analyses using other instruments or techniques (Asfour et al, 2020) and thus may not be considered as identifying features. Although the characterization of MP autofluorescence has recently been shown to be a promising tool for identifying polymer type (Monteleone et al, 2021a(Monteleone et al, , 2021b, until now, no instrument has shown the ability for near real-time identification of airborne MPs.…”

“…An often-overlooked material property of airborne microplastics that has the potential to specify particle type is their natural ability to fluoresce, or autofluoresce, which results from the spontaneous emission of light at one wavelength by the fluorophores of the polymers from excited electromagnetic states when exposed to higher-energy, lower-wavelength light (Lakowicz, 2006). Some commercially available polymers have previously been examined for their autofluorescence (Allen et al, 1976;Lionetto et al, 2022;Asfour et al, 2020;Hawkins and Yager, 2003;Piruska et al, 2005;Spizzichino et al, 2016;Monteleone et al, 2021c, a;Könemann et al, 2018), but the identification of polymer types using their autofluorescence has been limited. Most studies examine extrinsic fluorescence of MPs, which is a method of applying a dye stain that adheres to the plastics (Primpke et al, 2020;Capolungo et al, 2021), which only provide a means to distinguish MPs from other nonfluorescing materials when viewed on filter media from an optical microscope (Maes et al, 2017;Erni-Cassola et al, 2017).…”

Design and Material Characterization of an Inflatable Vaginal Dilator

“…Polymers such as polyurethane, nylon elastomers, thermoplastic elastomers, and silicones have been found to be ideal materials for manufacturing medical balloons and soft robotic actuators [27,28]. Hsiao et al (2019) reviewed soft robotic instruments used in surgery and found that silicone rubber is a commonly used material [27].…”

“…Hsiao et al (2019) reviewed soft robotic instruments used in surgery and found that silicone rubber is a commonly used material [27]. Asfour et al (2020) tested medical balloons made of different materials to examine the effect of material properties on the ablation of cardiac tissue [28]. Adamson et al (2004) developed a soft vaginal stent made of polyurethane foam to overcome the discomfort associated with rigid dilators [29].…”