Transparent antifouling material for improved operative field visibility in endoscopy

Abstract

Camera-guided instruments, such as endoscopes, have become an essential component of contemporary medicine. The 15–20 million endoscopies performed every year in the United States alone demonstrate the tremendous impact of this technology. However, doctors heavily rely on the visual feedback provided by the endoscope camera, which is routinely compromised when body fluids and fogging occlude the lens, requiring lengthy cleaning procedures that include irrigation, tissue rubbing, suction, and even temporary removal of the endoscope for external cleaning. Bronchoscopies are especially affected because they are performed on delicate tissue, in high-humidity environments with exposure to extremely adhesive biological fluids such as mucus and blood. Here, we present a repellent, liquid-infused coating on an endoscope lens capable of preventing vision loss after repeated submersions in blood and mucus. The material properties of the coating, including conformability, mechanical adhesion, transparency, oil type, and biocompatibility, were optimized in comprehensive in vitro and ex vivo studies. Extensive bronchoscopy procedures performed in vivo on porcine lungs showed significantly reduced fouling, resulting in either unnecessary or ∼10–15 times shorter and less intensive lens clearing procedures compared with an untreated endoscope. We believe that the material developed in this study opens up opportunities in the design of next-generation endoscopes that will improve visual field, display unprecedented antibacterial and antifouling properties, reduce the duration of the procedure, and enable visualization of currently unreachable parts of the body, thus offering enormous potential for disease diagnosis and treatment.

Novel materials

“…Specifically, Sunny et al (2) introduce a composite coating that consists of a porous solid matrix filled with a liquid, to yield a repellent surface that prevents fouling. This system, as demonstrated in transparent coatings on endoscopes through a comprehensive set of animal trials, involves a design inspired by the slippery surfaces of the carnivorous pitcher plant, in which the liquid-infused material spontaneously forms a biocompatible, lubricating, "nonstick" overlayer.…”

Emerging Applications of Bioinspired Slippery Surfaces in Biomedical Fields

“…(2) The whole porcine blood stained and cause fouling on uncoated endoscope after 1 dip (left), whereas coated endoscope shows blood repellency up to 100 dips (right). (3) Contact of the endoscope with lung secretions in an ex vivo lung . (c) Bacterial resistance of ePTFE liquid‐infused implants in vivo.…”

“…Camera‐guided instruments, such as endoscopes, are widely used in biomedical field. Recently, liquid‐infused surface coating with both optical transparency and blood‐fouling prevention properties were applied on glass lens which can be used directly on commercial‐available endoscopes for improved visibility in both ex vivo and in vivo (porcine lungs) studies . With optimized mechanical adhesion, oil type, transparency, and biocompatibility, the coated endoscopy showed excellent antifouling and antithrombosis, which result in unnecessary or 10–15 times shorter lens clearing process (Figure b).…”

Drop mobility on chemically heterogeneous and lubricant-impregnated surfaces

“…A reduction in biofilm attachment over a seven-day period of up to 96-99.6% is reported for some of the most common and opportunistic pathogens in both terrestrial and aquatic environments [86], an improvement of more than one order of magnitude vs. best-case scenario PEG-functionalized surfaces [88]. This easily implementable technology provides a promising approach to substantially reduce the risk of device infection and associated patient morbidity [89] and biocompatible coatings on medical devices to prevent thrombosis [90] or improve operative field visibility in endoscopy [91]. Slippery LISs show also good repellency against marine macrofouling organisms [73,92].…”