Fiber-Optic Microsphere-Based Antibody Array for the Analysis of Inflammatory Cytokines in Saliva

Abstract

Antibody microarrays have emerged as useful tools for high-throughput protein analysis and candidate biomarker screening. We describe here the development of a multiplexed microsphere-based antibody array capable of simultaneously measuring ten inflammatory protein mediators. Cytokine-capture microspheres were fabricated by covalently coupling monoclonal antibodies specific for cytokines of interest to fluorescently-encoded 3.1 μm polymer microspheres. An optical fiber bundle containing ∼50,000 individual 3.1 μm diameter fibers was chemically etched to create microwells in which cytokine-capture microspheres could be deposited. Microspheres were randomly distributed in the wells to produce an antibody array for performing a multiplexed sandwich immunoassay. The array responded specifically to recombinant cytokine solutions in a concentration-dependent fashion. The array was also used to examine endogenous mediator patterns in saliva supernatants from patients with pulmonary inflammatory diseases such as asthma and chronic obstructive pulmonary disease (COPD). This array technology may prove useful as a laboratory-based platform for inflammatory disease research and diagnostics, and its small footprint could also enable integration into a microfluidic cassette for use in point-of-care testing.

Saliva diagnostics – Current views and directions

“…Those technologies enable to measure proteins, DNA, transcripts (mRNA), electrolytes, and small molecules in saliva. 162 Currently developed tools include electrochemical sensing, 189 on-chip qRT-PCR, 190 fiber optic microsphere-based arrays, 191 high-throughput DNA microarrays, 192 surface plasmon resonance-based fiber optic sensors, 193 and microchip-based electrophoretic immunoassay. 137 The new avenue of point-of-care diagnostics for ''lab-ona-chip'' provides a new facet of point-of-care diagnostics, because it concurrently enables the detection of multiple biomarkers, and thus simultaneous diagnosis of many diseases.…”

Which Biomarkers Are Effective for Identifying Th2-Driven Inflammation in Asthma?

“…Even though clearly detectable levels of pro--inflammatory mediators and cytokines can be measured in saliva [ 135 ], surprisingly few studies have been published on the topic.…”

Zika virus infection spread through saliva – a truth or myth?

“…15 The proof-of-principle has been extended and we have also shown a strong correlation between 10 cytokines present in saliva and pulmonary disease, such as asthma, using a microsphere-based antibody array. 16 Therefore, we postulate that these new high-sensitive technologies able to measure multiples salivary biomarkers simultaneously, could become clinical tools for early detection and monitoring of prognosis and treatment for other diseases, including dengue and Zika infections. 17 Now that researchers around the world are committed to seek ways to eradicate ZIKV, all efforts in this direction should be considered.…”