Salivary diagnostics on paper microfluidic devices and their use as wearable sensors for glucose monitoring.

Microfluidic paper-based devices (µPADs) and wearable devices have been highly studied to be used as diagnostic tools due to their advantages such as simplicity and ability to provide instrument-free fast results. Diseases such as periodontitis and diabetes mellitus can potentially be detected through these devices by the detection of important biomarkers. This study describes the development of µPADs through craft cutter printing for glucose and nitrite salivary diagnostics. In addition, the use of µPADs integrated into a mouthguard as a wearable sensor for glucose monitoring is also presented. µPADs were designed to contain two detection zones for glucose and nitrite assays and a sampling zone interconnected by microfluidic channels. Initially, the analytical performance of the proposed µPADs was investigated and it provided linear behavior (r2 ≥ 0.994) in the concentration ranges between 0 to 2.0 mmol L-1 and 0 to 400 µmol L-1 for glucose and nitrite, respectively. Under the optimized conditions, the limits of detection achieved for glucose and nitrite were 27 µmol L-1 and 7 µmol L-1, respectively. Human saliva samples were collected from healthy individuals and patients previously diagnosed with periodontitis or diabetes and then analyzed on the proposed µPADs. The results found using µPADs revealed higher glucose concentration values in saliva collected from patients diagnosed with diabetes mellitus and greater nitrite concentrations in saliva collected from patients diagnosed with periodontitis, as expected. The results obtained on µPADs did not differ statistically from those measured by spectrophotometry. With the aim of developing paper-based wearable sensors, µPADs were integrated, for the first time, into a silicone mouthguard using a 3D-printed holder. The proof of concept was successfully demonstrated through the monitoring of the glucose concentration in saliva after the ingestion of chocolate. According to the results reported herein, paper-based microfluidic devices offer great potential for salivary diagnostics, making their integration into a silicone mouthguard possible, generating simple, low-cost, instrument-free, and powerful wearable sensors.

Short-term treatment with cabergoline can lead to tumor shrinkage in patients with nonfunctioning pituitary adenomas.

This study was carried out to evaluate the effectiveness of cabergoline in the treatment of nonfunctioning pituitary adenomas (NFPA), in a short-term follow-up period. Nineteen patients (10 men and 9 women) followed at the University Hospital of Brasilia and harboring nonfunctioning pituitary macroadenomas were enrolled in the study. Eleven patients were previously submitted to transsphenoidal surgery, and in 8 patients no previous treatment had been instituted. Their response to the use of cabergoline (2 mg/week) by 6 months was evaluated. Significant tumor shrinkage (above 25 % from baseline tumor volume) was observed in 6 (31.6 %) of the 19 patients, and no adverse effects were observed during treatment. In 9 patients (47.4 %), a reduction in tumor volume of at least 10 % was noted, whereas tumor growth was observed in four patients (increase above 25 % was only observed in one patient). Cabergoline (2 mg/week) can lead to significant tumor shrinkage in NFPA in a considerable number of patients, and this effect can be observed early (6 months after starting medication). Thus, this therapeutic strategy may be a low cost and safe alternative for treatment of NFPA in patients with remnant or recurrent tumor after transsphenoidal surgery or in those not operated by contraindications or refusal to surgical procedure.

Development of a sticker sealed microfluidic device for in situ analytical measurements using synchrotron radiation.

Shedding synchrotron light on microfluidic systems, exploring several contrasts in situ/operando at the nanoscale, like X-ray fluorescence, diffraction, luminescence, and absorption, has the potential to reveal new properties and functionalities of materials across diverse areas, such as green energy, photonics, and nanomedicine. In this work, we present the micro-fabrication and characterization of a multifunctional polyester/glass sealed microfluidic device well-suited to combine with analytical X-ray techniques. The device consists of smooth microchannels patterned on glass, where three gold electrodes are deposited into the channels to serve in situ electrochemistry analysis or standard electrical measurements. It has been efficiently sealed through an ultraviolet-sensitive sticker-like layer based on a polyester film, and The burst pressure determined by pumping water through the microchannel(up to 0.22 MPa). Overall, the device has demonstrated exquisite chemical resistance to organic solvents, and its efficiency in the presence of biological samples (proteins) is remarkable. The device potentialities, and its high transparency to X-rays, have been demonstrated by taking advantage of the X-ray nanoprobe Carnaúba/Sirius/LNLS, by obtaining 2D X-ray nanofluorescence maps on the microchannel filled with water and after an electrochemical nucleation reaction. To wrap up, the microfluidic device characterized here has the potential to be employed in standard laboratory experiments as well as in in situ and in vivo analytical experiments using a wide electromagnetic window, from infrared to X-rays, which could serve experiments in many branches of science.