Exhaled breath condensate as bioanalyte: from collection considerations to biomarker sensing

Abstract

Since the SARS-CoV-2 pandemic, the potential of exhaled breath (EB) to provide valuable information and insight into the health status of a person has been revisited. Mass spectrometry (MS) has gained increasing attention as a powerful analytical tool for clinical diagnostics of exhaled breath aerosols (EBA) and exhaled breath condensates (EBC) due to its high sensitivity and specificity. Although MS will continue to play an important role in biomarker discovery in EB, its use in clinical setting is rather limited. EB analysis is moving toward online sampling with portable, room temperature operable, and inexpensive point-of-care devices capable of real-time measurements. This transition is happening due to the availability of highly performing biosensors and the use of wearable EB collection tools, mostly in the form of face masks. This feature article will outline the last developments in the field, notably the novel ways of EBA and EBC collection and the analytical aspects of the collected samples. The inherit non-invasive character of the sample collection approach might open new doors for efficient ways for a fast, non-invasive, and better diagnosis.

The Bacterial Burden of Worn Face Masks – Observational Research and Literature Review

“…Besides substances sucked in from the outside, nutrients comprise exhaled proteins and other debris, exfoliated and dead epithelial cells. Condensing droplets in the exhaled breath contain non-volatile metabolites, salts, lipids and proteins along with intact and degraded bacteria and viruses [106]. This organic richness was visualised in our Bengal Rose staining.…”

“…Put simply: (i) the mask act as a filter trap with bacteria accumulating on its external and internal surfaces; (ii) the mask then acts as a "microbiological incubator" at the entrance of the airways; (iii) microorganisms may grow within the mask, nourished by skin debris, mucus and "exhaled breath condensate" [17,39,40,42,46,[105][106][107]. These trapped organisms/pathogens then may be inhaled, promoting infection of the respiratory tract [18,38] or, when distributed via air streams [108][109][110]117,135,136,168,169] the eye [79][80][81][82]116,135].…”

A clinical proteomics study of exhaled breath condensate and biomarkers for pulmonary embolism

“…by utilizing DIA. Mask-based collection of EBC even with real-time biosensors or filter based caption of exhaled proteins might be part of the solution in future studies, but much more research is needed before EBC analysis can transfer to clinical use [49].…”

Mask device as a new wearable sampler for breath analysis: what can we expect in the future?

“…In general, the sampling of mask samplers is mainly dependent on permeability and filtration efficiency of mask devices [ 6 , 7 ]. Compared to traditional breath sampling devices such as gas bag, gas canister, breath condenser, and adsorbent tube [ 9 – 13 ], the mask sampler has many advantages including safe, convenient, simple, wearable, and low-cost, and enables new possibilities to gain insights into human biology [ 13 , 14 ]. For example, the mask device is a safe breath sampler under highly infectious environments such as COVID-19 and tuberculosis.…”