The innovative diagnostic kit uses fluorescence-based detection to achieve 90% accuracy in detecting bladder cancer at an early stage.
Study: Diagnosis of early-stage bladder cancer through untreated point-of-care urine samples. Image credit: Orawan Pattarawimonchai/Shutterstock.com
In a recent study published in Nature Biomedical Engineeringa research team from the Republic of Korea investigated a new diagnostic system to detect early-stage bladder cancer using untreated urine samples.
The study showed that the device uses a two-layer system and suspended particles to send fluorescent signals, removing the need for sample preparation and making it a promising option for early detection of bladder cancer at home.
Background
Bladder cancer is one of the most common forms of cancer worldwide and is characterized by high rates of recurrence and progression. Early diagnosis, particularly during non-muscular infiltration, is crucial as it significantly improves survival outcomes.
However, current diagnostic methods such as cystoscopy and urine cytology are invasive, expensive and require specialized personnel. Furthermore, these approaches often lack sensitivity for early detection and are often affected by the heterogeneity of urine samples.
Several non-invasive, urine-based diagnostic methods, including molecular and enzymatic assays, have recently emerged. However, these methods often require sample pretreatment or fail to maintain accuracy in detecting biomarkers at low concentrations, especially in complex samples such as those with hematuria.
This unmet need for a sensitive, specific and user-friendly point-of-care diagnostic tool highlights the urgent need to develop accessible systems for the early detection and follow-up of bladder cancer.
The current study
In the present study, the team developed and validated a diagnostic device using a biphasic system containing buoyant organogel particles, which are produced by mixing low molecular weight compounds with organic media to detect bladder cancer at an early stage from urine samples that have not undergo treatment.
They named the assay the biological interference messenger-rectangular organelle with buoyancy lift, or BLOOM.
The system involved the enzymatic degradation of bigel membranes based on hyaluronic acid and containing organogel particles.
Upon degradation by urinary hyaluronidase, a biomarker for bladder cancer, the floating organogel particles will float on the oil layer, releasing solvochromic fluorescent dyes. Solvent chromic dyes change color when dissolved in different solvents.
The preparation of organopaste involved emulsifying Nile red dye, oleic acid, and 12-hydroxystearic acid in toluene, followed by cooling to form uniform, self-floating particles.
These particles were embedded in cross-linked hyaluronic acid hydrogels using glutaraldehyde. These bigel films were optimized for stability and sensitivity to low concentrations of hyaluronidase by adjusting the cross-linking density.
For the diagnostic application, the researchers added untreated urine samples to the bigel-coated surface, followed by a layer of dodecane oil to form the biphasic system. The fluorescence signal produced by the dissolved organogel in the oil phase was measured.
In addition, clinical validation of the device was conducted using 105 urine samples, including those from bladder cancer patients, subjects with other genitourinary diseases, and healthy controls.
The device was further tested using a low-cost, smartphone-based portable fluorescence reader. This minimized the need for laboratory infrastructure, allowing for potential home use.
Results
The study showed that the new diagnostic system effectively detected bladder cancer, including early-stage cases, with high sensitivity and specificity.
Using raw urine samples, the system achieved about 90% accuracy in a clinical trial involving 105 participants, which included bladder cancer patients, people with other genitourinary conditions, and healthy controls.
The device’s ability to detect hyaluronidase activity, a key biomarker of bladder cancer, was confirmed even in samples with complex compositions, such as those containing blood, from patients with hematuria.
In addition, the biphasic system was shown to be stable in maintaining signal purity by spatially separating the fluorescent signal from urinary components that could interfere with detection.
Furthermore, receiver operating characteristic curve analysis showed that the device demonstrated strong diagnostic performance for early-stage cancers. In addition, it reliably differentiated cases of non-muscle invasive bladder cancer (NMIBC) from healthy controls and other genitourinary diseases, which are commonly missed by existing diagnostic tools.
Compared to the Food and Drug Administration (FDA)-approved NMP22 or Nuclear Matrix Protein 22 test, the new system showed significantly higher sensitivity, especially for NMIBC and early-stage cases.
The device also overcame the challenges posed by hematuria and provided accurate results regardless of the blood content of the samples.
In addition, the integration of a smartphone-based fluorescence reader further validated the practicality of the system, enabling low-cost, consistent, and user-friendly testing.
These findings suggest that the BLOOM system is a promising tool for non-invasive, home-based screening and early detection of bladder cancer and could address critical gaps in existing diagnostic approaches.
conclusions
In summary, the research team developed a sensitive, specific, and user-friendly diagnostic tool for bladder cancer that allows early detection using unprocessed urine samples.
The two-phase system, combined with a smartphone-based fluorescence reader, offers an accessible and affordable solution for home testing.
Furthermore, addressing the limitations of existing methods, such as interference from hematuria and low biomarker sensitivity, this innovation represents a significant advance in non-invasive cancer diagnosis.
Journal Reference:
Keum, C., Yeom, H., Noh, TI, Yi, SY, Jin, S., Kim, C., Shim, JS, Yoon, SG, Kim, H., Lee, KH, Kang, SH, & Jeong, Y. (2024). Diagnosis of early-stage bladder cancer through untreated point-of-care urine samples. Nature Biomedical Engineering. doi:10.1038/s41551024012980.