A nano-biosensor for chair side monitoring of salivary
MMP-8 in periodontitis
OJ-Bio, Centre for Oral Health Research at Newcastle University Dental School (Prof Philip Preshaw and Dr John Taylor) and Orla Protein Technologies were awarded an Innovate UK grant to develop a novel prototype device for evaluating periodontitis at the chair side through measuring salivary MMP-8, which along with other matrix metalloproteinases (MMPS) is a collagen-cleaving enzyme that initiates the destruction of gum tissue leading to chronic periodontitis.
Objectives
Chair side monitoring of inflammatory mediators of periodontitis can provide immediate information about disease activity, which can inform patient management. For this purpose, we aimed to develop a prototype device, which can effectively measure salivary MMP-8, an established biomarker of periodontitis.
Methods
Surface acoustic wave (SAW) biosensor chips were coated with an MMP-8-specific capture antibody. The detection of soluble MMP-8 in saliva samples was carried out by application of the sample to the biosensor chips followed by signal enhancement with a second MMP-8 specific antibody. The analytical performance of the SAW biosensor was compared to standard ELISA (Quantikine, R&D Systems) using unstimulated saliva samples obtained from patients with untreated periodontitis (N=58), gingivitis (N=54) and periodontally healthy volunteers (N=65).
Results
In agreement with the published literature, levels of salivary MMP-8 detected using both analytical approaches were significantly higher in periodontitis as compared to gingivitis (p< 0.001) and healthy controls (p< 0.001). Receiver operator characteristic analysis for distinguishing periodontitis from health revealed an almost identical performance using the novel SAW device when compared to the current lab-based method (area under curve values: ELISA 0.93; SAW 0.89).
The assay time for our prototype device is approximately 15 minutes, which compares favourably to the minimum 2-3 hours required for ELISA testing, which requires considerable technical expertise, laboratory facilities and expensive analytical equipment.
Benefits
• Chair side analysis
• Ease of use
• Low cost
• Results within the timeframe of a dental appointment
• Can be used by dentists, other clinical staff and patients with minimal training
• Accurate and reliable (equivalent in performance to lab-based tests)
Conclusions and Future Developments
The prototype SAW biosensor represents a promising development towards effective chair side monitoring of periodontitis with similar performance.
Further developments will focus on the refinement and clinical efficacy of the novel biosensors. Reduction of assay time will be one focus, as initial developments suggested that reducing it to 8 minutes or lower could be possible.