Saliva Liquid Biopsy for Point-of-Care Applications

Abstract

Saliva is a non-invasive biofluid, which is easy to collect, transport, and store. Because of its accessibility and connection to systemic diseases, saliva is one of the best candidates for the advancement of point-of-care medicine, where individuals are able to easily monitor their health status by using portable convenient tools such as smartphones. There are a variety of scenarios with which saliva can be used: studies have been conducted on using saliva to measure stress hormones, enzyme levels, developmental disease biomarkers, and even cancer mutations. If validated biomarkers were combined with high-quality detection tools, saliva would open up a new frontier in high-quality healthcare, allowing physicians and patients to work together for real-time health monitoring and high-impact personalized preventative medicine. One of the most exciting emerging frontiers of saliva is liquid biopsy, which is a non-invasive means to assess the presence and characteristics of cancer in a patient. This article will review current basic knowledge of biomarkers, review their relation to different diseases and conditions, and explore liquid biopsy for point-of-care applications.

Advances in liquid biopsy on-chip for cancer management: Technologies, biomarkers, and clinical analysis

“…Given the relative novelty of liquid biopsy, there is still active research in which of these fluids are suitable for a given application, and the proper sample handling procedures for their use. While the bulk of the studies have focused on serum and plasma, saliva has been used mainly for oral and lung cancers[43], cerebrospinal fluid has been used for central nervous system cancers[44], and urine has been used for those relating to the urinary tract[45], [46]. These fluids and the potential biomarkers that can be derived from them are shown in Figure 4 below.…”

“…It is an attractive sample type because of its ease of collection and storage, and biomarker validation for saliva samples is an active area of research[43]. Compared to blood and the blood derivatives described above, saliva collection is a truly noninvasive procedure.…”

“…Compared to blood and the blood derivatives described above, saliva collection is a truly noninvasive procedure. Research has linked salivary biomarker profiles to systemic diseases, oral diseases, and pharmacology for drug response[43]. Saliva has been linked to head and neck cancer, oropharyngeal cancers caused by human papilloma virus (HPV), and lung cancers.…”

“…In terms of sample collection, some work has been done to study the collection and storage methods required for successful analysis of biomarkers[43], [55]. There is not a wide consensus over whether the saliva sample should be centrifuged prior to processing and how quickly the sample should be analyzed, but some research has shown that samples should be used within an hour, and that centrifugation can be performed depending on whether it is cells or smaller molecules to be analyzed[43].…”

“…There is not a wide consensus over whether the saliva sample should be centrifuged prior to processing and how quickly the sample should be analyzed, but some research has shown that samples should be used within an hour, and that centrifugation can be performed depending on whether it is cells or smaller molecules to be analyzed[43]. In this paper, technologies that use saliva for lung cancer related applications are reviewed.…”