University of California Los Angeles
Refinement and Validation of a Portable, Salivary Biosensor of Psychosocial Stress
Our transdisciplinary application proposes the development, refinement and field validation of biosensors to allow point-of-care (POC) measurement of salivary biomarkers of exposure to systemic and psychosocial stressors. Unlike the intrusive sampling of blood and urine, the ease of saliva collection greatly facilitates subject compliance and allows repeat, self-administered naturalistic sampling conducive to large-scale population studies of stress-health outcome interactions. Our proposed biosensing technology will render salivary stress biomarker measurement field-practical and accessible to end-users without the need for processing in distant, centralized laboratories.
Our initial efforts have focused on the rapid measurement of salivary alpha-amylase (sAA), a putative bioindicator of the body's adrenergic stress response and build on an extant biosensor prototype. We will first optimize the technical performance characteristics of the sAA biosensor in a cohort of healthy subjects by:
- Establishing calibration curves for the portable sAA biosensor and comparing it to laboratory assayed sAA,
- Examining biosensor reliability (precision and accuracy) over the diurnal cycle, and
- Verifying its validity as a exposure assessment tool under conditions of low and high stress.
Subsequently, we will conduct small-scale field testing and functional validation of the sAA biosensor in a cohort of subjects following an acute systemic stressor (e.g., traumatic injury). In this field validation phase, we will
- Test collection procedures and validity of the sAA biosensor across variations in systemic and psychosocial stress (hospital intake, 10 days post-surgery, 30-day post-surgery),
- Examine potential confounding effects of predisposing vulnerabilities (e.g., sociodemographics, stress burden, social support) and systemic milieu (e.g., substance use, health/lifestyle behaviors) on biomarker levels, and
- Assess the predictive validity of biosensor SAA for maladaptive psychological (e.g., distress, anxiety, depression) and behavioral symptoms following the extreme stressor.
Concurrently, we will develop and refine the technical capabilities of a biosensor platform for measuring salivary cortisol and seek to expand its capabilities to permit multiplexed assays of other salivary analytes reflective of the stress response (e.g.,DHEA, testosterone) as well as licit and illicit substance use.
Our ultimate goal is to develop a universal, portable platform to operationalize the psychobiology of stress and substance use by detecting and reliably quantifying relevant salivary response indicators. The synergistic combination of complementary research expertise and the body of precursor research devoted to psychosocial stress and its biomarkers maximize the likelihood that our research program will produce field-deployable biosensors of the stress response.