Inkjet Printed ZnO Sensors for Early Prostate Cancer Detection by Means of Urine Odor Analysis

Analysis of urinary volatile organic compounds for prostate cancer diagnosis: A systematic review

Context

Prostate-specific antigen is non-specific for prostate cancer. This is improved by multiparametric MRI but a significant amount of indolent prostate cancer is detected by the current MRI pathway and data is emerging that clinically significant cancers maybe missed using a standard PSA threshold. Volatile organic compound (VOC) analysis may offer novel biomarkers for prostate cancer and clinically significant disease.

Objective

To perform a systematic review of the literature to evaluate the current evidence for the use of VOCs as novel biomarkers for prostate cancer and clinically significant prostate cancer.

Evidence Acquisition

A systematic search of MEDLINE, Scopus, Web of Science and the Cochrane Library was undertaken by two independent reviewers and papers were assessed for inclusion in the review. Study characteristics, sensitivity and specificity of GC-MS or eNose were extracted. Risk of bias and applicability issues were determined using QUADAS 2 and the quality of reporting using the STARD checklist.

Evidence Synthesis

Nineteen studies were included, of which 6 utilised eNose and 13 GC-MS. eNose sensitivity and specificity were 0.71-0.95 and 0.79-0.96, respectively, and GC-MS found a sensitivity and specificity of 0.66-1.00 and 0.53-0.97, respectively. There were concerns about bias in patient recruitment due to differences in the timing of the index test relative to the reference standard.

Conclusion

This review has found promising early results for urinary metabolomics in the detection of prostate cancer. However, there is a need for larger, high-quality studies to validate this. Future work should focus on the detection of clinically significant prostate cancer.

Printing MEMS: Application of Inkjet Techniques to the Manufacturing of Inertial Accelerometers

In the last few years, the manufacturing of microelectromechanical systems (MEMS) by means of innovative tridimensional and bidimensional printing technologies has significantly catalyzed the attention of researchers. Inkjet material deposition, in particular, can become a key enabling technology for the production of polymer-based inertial sensors characterized by low cost, high manufacturing scalability and superior sensitivity. In this paper, a fully inkjet-printed polymeric accelerometer is proposed, and its manufacturing steps are described. The manufacturing challenges connected with the inkjet deposition of SU-8 as a structural material are identified and addressed, resulting in the production of a functional spring-mass sensor. A step-crosslinking process allows optimization of the final shape of the device and limits defects typical of inkjet printing. The resulting device is characterized from a morphological point of view, and its functionality is assessed in performing optical readout. The acceleration range of the optimized device is 0-0.7 g, its resolution is 2 × 10-3 g and its sensitivity is 6745 nm/g. In general, the work demonstrates the feasibility of polymeric accelerometer production via inkjet printing, and these characteristic parameters demonstrate their potential applicability in a broad range of uses requiring highly accurate acceleration measurements over small displacements.

The solvent effect on the morphology and molecular ordering of benzothiadiazole-based small molecule for inkjet-printed thin-film transistors

A small molecule organic semiconductor, D(D'-A-D')₂ comprising benzothiadiazole as an acceptor, 3-hexylthiophene, and thiophene as donors, was successfully synthesized. X-ray diffraction and atomic force microscopy were used to investigate the effect of a dual solvent system with varying ratios of chloroform and toluene on film crystallinity and film morphology via inkjet printing. The film prepared with a chloroform to toluene ratio of 1.5 : 1 showed better performance with improved crystallinity and morphology due to having enough time to control the arrangement of molecules. In addition, by optimizing ratios of CHCl₃ to toluene, the inkjet-printed TFT based on 3HTBTT using a CHCl₃ and toluene ratio of 1.5 : 1 was successfully fabricated and exhibited a hole mobility of 0.01 cm² V^-1 s^-1 due to the improved molecular ordering of the 3HTBTT film.

Drift compensation on electronic nose data for non-invasive diagnosis of prostate cancer by urine analysis

Diagnostic protocol for prostate cancer (KP) is affected by poor accuracy and high false-positive rate. The most promising innovative approach is based on urine analysis by electronic noses (ENs), highlighting a specific correlation between urine alteration and KP presence. Although EN could be exploited to develop non-invasive KP diagnostic tools, no study has already introduced EN into clinical practice, most probably because of drift issues that hinder EN scaling up from research objects to large-scale diagnostic devices. This study, proposing an EN for non-invasive KP detection, describes the data processing protocol applied to a urine headspace dataset acquired over 9 months, comprising 81 patients with KP and 41 controls, for compensating the drift. It proved effective in mitigating drift on 1-year-old sensors by restoring accuracy from 55% up to 80%, achieved by new sensors not subjected to drift. The model achieved, on double-blind validation, a balanced accuracy of 76.2% (CI_95% 51.9–92.3).

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Urine odor alteration due to prostate cancer can be detected by electronic noses

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Sensors drift hinders electronic nose scaling up to large-scale diagnostic devices

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OSC mitigates drift on 1-year-old sensors, restoring accuracy from 55% up to 80%

Optimization of training and measurement protocol for eNose analysis of urine headspace aimed at prostate cancer diagnosis

More than one million new cases of prostate cancer (PCa) were reported worldwide in 2020, and a significant increase of PCa incidence up to 2040 is estimated. Despite potential treatability in early stages, PCa diagnosis is challenging because of late symptoms' onset and limits of current screening procedures. It has been now accepted that cell transformation leads to release of volatile organic compounds in biologic fluids, including urine. Thus, several studies proposed the possibility to develop new diagnostic tools based on urine analysis. Among these, electronic noses (eNoses) represent one of the most promising devices, because of their potential to provide a non-invasive diagnosis. Here we describe the approach aimed at defining the experimental protocol for eNose application for PCa diagnosis. Our research investigates effects of sample preparation and analysis on eNose responses and repeatability. The dependence of eNose diagnostic performance on urine portion analysed, techniques involved for extracting urine volatiles and conditioning temperature were analysed. 192 subjects (132 PCa patients and 60 controls) were involved. The developed experimental protocol has resulted in accuracy, sensitivity and specificity of 83% (CI_95% 77-89), 82% (CI_95% 73-88) and 87% (CI_95% 75-94), respectively. Our findings define eNoses as valuable diagnostic tool allowing rapid and non-invasive PCa diagnosis.