Effects of Supplemental Drugs on Hexaminolevulinate (HAL)-Induced PpIX Fluorescence in Bladder Cancer Cell Suspensions.

Seven different inhibitors of the heme metabolic pathway were applied in combination with HAL to study the formation of PpIX in bladder cancer HT1197 and normal fibroblast HFFF2 cells ex vivo, specifically with the aim to increase the fluorescence contrast between cancer and non-cancer cells. The mRNA expression of enzymes involved in the heme biosynthesis pathway were measured via PCR following incubation with the drugs in order to link the fluorescence levels and metabolic activity. The exogenous administration of HAL does lead to cancer-specific PpIX accumulation. However, the contrast between cancer and normal cells in suspension was not enhanced by the enzyme inhibitors and iron-chelating agents tested, nor did the mRNA expression necessarily correlate with the fluorescence intensity. The results indicate that a difference in the metabolic activity of cells in suspension may limit the applicability of exogenous enzyme inhibitor administration as a mean to improve the fluorescence-based detection of cancer cells shed in body fluids.

Prostate cancer detection: a systematic review of urinary biosensors.

BACKGROUND: Current diagnostic methods for prostate cancer are invasive and lack specificity towards aggressive forms of the disease, which can lead to overtreatment. A new class of non-invasive alternatives is under development, in which urinary biomarkers are detected using biosensing devices to offer rapid and accurate prostate cancer diagnosis. These different approaches are systematically reviewed and their potential for translation to clinical practice is evaluated. METHODS: A systematic review of the literature was performed in May 2021 using PubMed Medline database, Embase, and Web of Science. The objective was to review the structural designs and performance of biosensors tested on urine samples from patients with prostate cancer. RESULTS: A total of 76 records were identified. After screening and eligibility, 14 articles were included and are discussed in this paper. The biosensors were discussed based on the target biomarkers and detection technologies used, as well as the results of the clinical studies. Most of the works reported good discrimination between patients with prostate cancer and controls. CONCLUSIONS: This review highlights the potential of urinary biosensors for non-invasive prostate cancer detection. However, clinical studies have so far only been conducted on small cohorts of patient, with large scale trials still needed to validate the proposed approaches. Overall, the consensus arising from the proof of concepts studies reviewed here, is that an adequate combination of biomarkers into multiplex biosensor platforms is required to achieve accurate diagnostic tests. Furthermore, whether such devices can discriminate between aggressive and indolent cancer has not yet been addressed, because it entails optimized biomarkers panels and long-term clinical trials.

Selective Microfluidic Capture and Detection of Prostate Cancer Cells from Urine without Digital Rectal Examination.

Urine-based biomarkers have shown suitable diagnostic potential for prostate cancer (PCa) detection. Yet, until now, prostatic massage remains required prior to urine sampling. Here, we test a potential diagnostic approach using voided urine collected without prior digital rectal examination (DRE). In this study, we evaluated the diagnostic performance of a microfluidic-based platform that combines the principle of photodynamic diagnostic with immunocapture for the detection of PCa cells. The functionality and sensitivity of this platform were validated using both cultured cells and PCa patient urine samples. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) demonstrated this platform had a detection limit of fewer than 10 cells per 60 µL and successfully validated the presence of a PCa biomarker in the urine of cancer patients without prior DRE. This biosensing platform exhibits a sensitivity of 72.4% and a specificity of 71.4%, in suitable agreement with qRT-PCR data. The results of this study constitute a stepping stone in the future development of noninvasive prostate cancer diagnostic technologies that do not require DRE.

Plasma Deposited Polyoxazoline Films Integration Into Spiral Microfluidics for the Targeted Capture of Size Selected Cells.

Biomolecules readily and irreversibly bind to plasma deposited Polyoxazoline thin films in physiological conditions. The unique reactivity of these thin films toward antibodies is driving the development of immunosensing platforms for applications in cancer diagnostics. However, in order for these coatings to be used as advanced immunosensors, they need to be incorporated into microfluidic devices that are sealed via plasma bonding. In this work, the thickness, chemistry and reactivity of the polyoxazoline films were assessed following plasma activation. Films deposited from methyl and isopropenyl oxazoline precursors were integrated into spiral microfluidic devices and biofunctionalized with prostate cancer specific antibodies. Using microbeads as model particles, the design of the spiral microfluidic was optimised to enable the size-based isolation of cancer cells. The device was tested with a mixed cell suspension of healthy and malignant prostate cells. The results showed that, following size-specific separation in the spiral, selective capture was achieved on the immunofunctionalised PPOx surface. This proof of concept study demonstrates that plasma deposited polyoxazoline can be used for immunosensing in plasma bonded microfluidic devices.

Improving hexaminolevulinate enabled cancer cell detection in liquid biopsy immunosensors.

Hexaminolevulinate (HAL) induced Protoporphyrin IX (PpIX) fluorescence is commonly used to differentiate cancer cells from normal cells in vivo, as for instance in blue light cystoscopy for bladder cancer diagnosis. A detailed approach is here provided to use this diagnostic principle ex vivo in an immunosensor device, towards enabling non-invasive cancer diagnostic from body fluids, such as urine. Several factors susceptible to affect the applicability of HAL-assisted diagnosis in body fluids were tested. These included the cell viability and its impact on PpIX fluorescence, the storage condition and shelf life of HAL premix reagent, light exposure (360-450 nm wavelengths) and its corresponding effect on both intensity and bleaching of the PpIX fluorescence as a function of the microscopy imaging conditions. There was no significant decrease in the viability of bladder cancer cells after 6 h at 4 °C (student's t-test: p > 0.05). The cellular PpIX fluorescence decreased in a time-dependent manner when cancer cells were kept at 4 °C for extended period of time, though this didn't significantly reduce the fluorescence intensity contrast between cancer and non-cancer cells kept in the same condition for 6 h. HAL premix reagent kept in long term storage at 4 °C induced stronger PpIX fluorescence than reagent kept in the - 20 °C freezer. The PpIX fluorescence was negatively affected by repeated light exposure but increased with illumination intensity and exposure time. Though this applied to both healthy and cancer cell lines, and therefore did not statistically improved the differentiation between cell types. This study revealed important experimental settings that need to be carefully considered to benefit from the analytical potential of HAL induced fluorescence when used in technologies for the diagnosis of cancer from body fluids.

Cancer cell detection device for the diagnosis of bladder cancer from urine.

Bladder cancer is common and has one of the highest recurrence rates. Cystoscopy, the current gold standard diagnosis approach, has recently benefited from the introduction of blue light assisted photodynamic diagnostic (PDD). While blue light cystoscopy improves diagnostic sensitivity, it remains a costly and invasive approach. Here, we present a microfluidic-based platform for non-invasive diagnosis which combines the principle of PDD with whole cell immunocapture technology to detect bladder cancer cells shed in patient urine ex vivo. Initially, we demonstrate with model cell lines that our non-invasive approach achieves highly specific capture rates of bladder cancer cells based on their Epithelial Cell Adhesion Molecule expression (>90%) and detection by the intensity levels of Hexaminolevulinic Acid-induced Protoporphyrin IX fluorescence. Then, we show in a pilot study that the biosensor platform successfully discriminates histopathologically diagnosed cancer patients (n = 10) from non-cancer controls (n = 25). Our platform can support the development of a novel non-invasive diagnostic device for post treatment surveillance in patients with bladder cancer and cancer detection in patients with suspected bladder cancer.

Functional nanothin films plasma-deposited from 2-isopropenyl-2-oxazoline for biosensor applications.

Plasma polymers derived from oxazoline precursors present a range of versatile properties that is fueling their use as biomaterials. However, coatings deposited from commonly used methyl and ethyl oxazoline precursors can be sensitive to the plasma deposition conditions. In this work, we used various spectroscopic methods (ellipsometry, x-ray photoelectron spectroscopy, and time of flight secondary ion mass spectrometry) and cell viability assays to evaluate the transferability of deposition conditions from the original plasma reactor developed by Griesser to a new wider, reactor designed for upscaled biosensors applications. The physicochemical properties, reactivity, and biocompatibility of films deposited from 2-isopropenyl-2-oxazoline were investigated. Thanks to the availability of an unsaturated pendant group, the coatings obtained from this oxazoline precursor are more stable and reproducible over a range of deposition conditions while retaining reactivity toward ligands and biomolecules. This study identified films deposited at 20 W and 0.012 mbar working pressure as being the best suited for biosensor applications.

Shedding Light on Bladder Cancer Diagnosis in Urine.

Blue light cystoscopy (BLC) is the most recent clinical approach in the detection and diagnosis of bladder cancer, a common type of cancer with a high rate of recurrence. Representing a significant advance over previous approaches, this photodynamic diagnostic technique uses a photosensitiser prodrug as an adjunct to white light cystoscopy to enhance the in vivo detection of malignant tissues in the bladder based on their distinctive fluorescence. Whilst it does improve detection rates, BLC remains an invasive and costly procedure. Meanwhile, a variety of noninvasive urine detection methods and related microdevices have been developed, none of which have yet entered routine clinical use due to unsatisfactory sensitivity. Following a brief description of the current approaches and their limitations, we provide here a systematic review of a newer niche research aiming to develop a noninvasive adaptation of photodynamic diagnosis. The research to date surrounding the ex situ use of photosensitiser prodrugs for urinary diagnosis of bladder cancer is also discussed.

Plasma enabled devices for the selective capture and photodynamic identification of prostate cancer cells.

Prostate cancer is the second most common cancer in men and the second leading cause of male cancer deaths. The current blood test for detecting prostate cancers measures prostate-specific antigen. It has many limitations including a very high rate of false positives. Herein, prostate-specific membrane antigen (PSMA) based immunocapture and hexaminolevulinate (HAL) based photodetection are integrated into a new diagnostic device designed to selectively identify whole prostate cancer cells from voided urine with the aim of providing an accurate noninvasive alternative to current diagnosis methods. Prestained, prostate cancer cells spiked in urine samples at concentrations ranging from 1500 to 2000 cells/ml were captured with 89% sensitivity and 95% specificity. HAL, a cancer specific photosensitizer, was then used to circumvent the need for prestaining. Optimum HAL incubation conditions were identified (50 µM at 37 °C for 2 h) where the mean HAL-induced fluorescence intensity of LNCaP cells was three times that of healthy PNT2 cells, thus providing an independent way to discriminate captured cancer cells from background metabolites. Combining anti-PSMA immunocapture with HAL-induced fluorescent detection, 86% sensitivity and 88% selectivity were achieved, thereby proving the validity of the dual-method for the selective photospecific detection of prostate cancer cells.

Probing Hexaminolevulinate Mediated PpIX Fluorescence in Cancer Cell Suspensions in the Presence of Chemical Adjuvants.

Exogenous administration of hexaminolevulinate (HAL) induces fluorescent protoporphyrin IX (PpIX) accumulation preferentially in cancer cells. However, the PpIX fluorescence intensities between noncancer and cancer cells are highly variable. The contrast between cancer and noncancer cells may be insufficient to reliably discriminate, especially at the single cell level in cancer diagnostics. This study examines the use of the chemical adjuvants dimethylsulphoxide (DMSO) or deferoxamine (DFO) to enhance the HAL induced PpIX accumulation in cancer cells. Our results showed that in some of the incubation conditions tested, the addition of DFO with HAL significantly increased PpIX 21 fluorescence of adherent monolayer cancer cells, but this was never the case for cells in suspension. Permeabilisation with DMSO did not increase PpIX fluorescence. Cell-to-cell interaction may well play an important role in the PpIX accumulation when suspended cells are treated in HAL and adjuvant chemicals.

Biosensor device for the photo-specific detection of immuno-captured bladder cancer cells using hexaminolevulinate: An ex-vivo study.

Exogenous administration of the photodynamic agent hexaminolevulinate induces Protoporphyrin IX (PpIX) accumulation in malignant tissue. This may enable differentiation from healthy tissues by emission of a distinctive red fluorescence. It provides the photo-specific detection when excited with blue light at 405 nm. This study determines the ex-vivo processing conditions (time, concentration, temperature and addition of a fluorescent dye) required for HAL-induced PpIX fluorescence to successfully discriminate between bladder cancer and benign fibroblast cells shed in urine at the single cell level. HAL-induced fluorescence was 4.5 times brighter in cancer cells than non-cancer cells when incubated in the optimum conditions, and could be used to correctly identified bladder cancer cells captured within a newly developed immunofunctionalized biosensor with 88% efficiency. This biosensor is designed to facilitate the immuno-capture of cancer cells by interaction with carcinoma specific anti Epithelial Cell Adhesion molecule (anti-EpCAM) antibodies. Anti-EpCAM antibodies were immobilized on polyoxazoline (POx) plasma polymers by covalent bonds in microfluidic channels. Combining photodynamic and immunoselective approach therefore constitute a promising approach for the non-invasive diagnosis of bladder cancer with two independent level of confidence. OBJECTIVE: This study investigate the relationship between different regulatory factors (time, concentration, temperature and addition of a fluorescent dye) and Hexaminolevulinate (HAL)-mediated photodynamic diagnosis of bladder cancer (PDD) in vitro. We examine the natural photosensitizer Protoporphyrin IX (PpIX) fluorescence induced by HAL in several human bladder cancer cell lines and one non-cancer foreskin fibroblast cell line and identify the processing conditions that maximise the difference in fluorescence intensity between malign and benign cell types. The detection of HAL induced fluorescence at a single cell level by a selective cancer cell capture platform is also tested. MATERIALS AND METHODS: Experiments were performed on cultured monolayer cells and cells in suspension. The cell lines examined included the transitional epithelium carcinoma cell lines HT1197, HT1376, EJ138 and RT4, and the non-cancer foreskin fibroblasts HFF. Cells were incubated with HAL in various doses, time and temperature settings. We also used the nuclear red as a tool to study the PpIX subcellular localization. PpIX fluorescence intensities were measured and analysed using fluorescence microscope software. Finally, we evaluated the possibility of using HAL to discriminate between cancer and non-cancer cells from a mixed cell population using a newly developed immunofunctionalized microfluidic platform. RESULTS: The accumulation of PpIX in bladder cancer cells was significantly higher than in non-cancer cells, both cultured monolayer cells and cells in suspension. Effectively, the fluorescence intensity was 4.5 times brighter in bladder cancer cells than non-cancer foreskin fibroblast cells when incubated in the optimum condition, in which the nuclear stain adjuvant acted as a fluorescence enhancer. Cancer cells displayed PpIX accumulated mainly in mitochondria but none or very little PpIX was observed in non-cancer cells. HAL-induced fluorescence could be used to correctly identify bladder cancer cells within the EpCAM conjugated POx based microfluidic sensor with an 88% capture selectivity rate. CONCLUSIONS: These findings prove that the application of HAL-induced PpIX fluorescence can successfully distinguish between cancer and non-cancer cells in vitro. This test can provide advanced second level of confidence on the cancerous nature of cells captured by the immunofunctionalized bladder cancer diagnostic platform.

Comparison of the NucliSens easyMAG and Qiagen BioRobot 9604 nucleic acid extraction systems for detection of RNA and DNA respiratory viruses in nasopharyngeal aspirate samples.

The NucliSens easyMAG and BioRot 9604 automated nucleic acid extraction systems were evaluated and compared with the manual QIAamp (Qiagen) extraction method for their abilities to extract nucleic acid from nasopharyngeal aspirate samples for the detection of RNA and DNA respiratory viruses. The nucleic acids recovered by all three methods gave comparable sensitivities in PCR tests, and the three methods gave comparable viral loads. There was no evidence of residual PCR inhibitors and no evidence of PCR cross-contamination.

Evaluation and validation of an enzyme-linked immunosorbent assay and an immunochromatographic test for serological diagnosis of severe acute respiratory syndrome.

A newly developed severe acute respiratory syndrome (SARS)-specific enzyme-linked immunosorbent assay (ELISA) was further validated to confirm cutoff values and evaluate its diagnostic performance with clinical samples. In parallel, an immunochromatographic test was also evaluated. A total of 227 clinical serum specimens collected from SARS patients were used in the study, together with 385 samples from healthy donors. By use of an immunofluorescent (IF) test as the "gold standard", both the ELISA and the immunochromatographic test were able to detect immunoglobulin G antibodies to SARS not only from late-convalescent-stage samples (>21 days from the onset of clinical symptoms), as previously established, but also from early-acute-phase samples (1 to 10 days from onset). The ELISA, using an optical density (OD) of 0.25 as its cutoff value, produced the best sensitivity while maintaining high specificity. It detected SARS-specific antibodies in 58, 70, 75, and 95%, respectively, of the four groups of samples collected from patients 1 to 10 days, 11 to 20 days, 21 to 30 days, and more than 30 days after the onset of clinical symptoms. Similarly, the immunochromatographic test detected SARS-specific antibodies in 55, 68, 81, and 79% of the four groups, respectively. The overall specificities for the ELISA and the rapid test were 99.5 and 97.7%, respectively. Although the positive correlation observed between the ELISA OD values and the IF titers was moderate (r = 0.6915; P < 0.001), the detection rates of both the ELISA and the rapid test were found well in agreement with the IF titers.