Selective Collection of Exhaled Breath Condensate for Noninvasive Screening of Breath Glucose.

BACKGROUND: Although exhaled breath condensate (EBC) is a promising noninvasive sample for detecting respiratory analytes such as glucose, current EBC collection methods yield inconsistent results. METHODS: We developed a custom EBC collection device with a temperature-based algorithm to selectively condense alveolar air for reproducible EBC glucose detection. We characterized the condensate volumes and the corresponding glucose concentrations. We performed a pilot study demonstrating its use during oral glucose tolerance tests. RESULTS: The novel device selectively captured alveolar air resulting in slightly higher and less variable glucose concentrations than the overall EBC. Participants with type 2 diabetes demonstrated significantly higher blood plasma-EBC glucose ratios than normoglycemic participants. CONCLUSIONS: Temperature-based selective EBC collection allows EBC glucose measurement and is a promising sampling method to distinguish patients with and without diabetes.

Noninvasive glucose detection in exhaled breath condensate.

Two-thirds of patients with diabetes avoid regularly monitoring their blood glucose levels because of the painful and invasive nature of current blood glucose detection. As an alternative to blood sample collection, exhaled breath condensate (EBC) has emerged as a promising noninvasive sample from which to monitor glucose levels. However, this dilute sample matrix requires sensors capable of detecting glucose with high resolution at nanomolar and micromolar concentrations. Recent developments in EBC collection methods and highly sensitive glucose biosensors provide a path toward enabling robust and sensitive glucose detection in EBC. This review addresses current and emerging EBC collection and glucose sensing modalities capable of quantifying glucose in EBC samples. We highlight the opportunities and challenges for development and integration of EBC glucose detection systems that will enable clinically robust and accurate EBC glucose measurements for improved glycemic control.

Selective Collection and Condensation of Exhaled Breath for Glucose Detection.

Exhaled breath condensate (EBC) is a promising non-invasive sample for the detection of various analytes, such as glucose. However, the methods used to collect EBC are highly inconsistent; the variable dilution factors associated with water vapor and the inclusion of dead space air significantly impact the reliability of reported analyte concentrations in EBC. For example, current EBC glucose measurements have resulted in dilution factors ranging from 1/1000 to 1/50000 [1]. There is a need for a systematic and selective EBC collection method to ensure accurate analyte detection and quantification. Herein, we develop and characterize a low-cost, portable condenser which selectively collects exhaled breath that has been exchanged with lung fluid in a temperature-based manner. We demonstrate that for ~15 L of exhaled air, our device can condense reproducible volumes of EBC $({\lt} 130~ {\mu } \mathrm {L})$ in under 3 minutes (p > 0.05, n = 3). Furthermore, our results indicate that a higher concentration of glucose can be detected in the collected sample with selective valve opening (p < 0.05, n = 3). The development of this device enables a repeatable and robust collection method to enable the evaluation of correlations between analytes in EBC and blood.

3D-Printed Multidrug-Eluting Stent from Graphene-Nanoplatelet-Doped Biodegradable Polymer Composite.

Patients with percutaneous coronary intervention generally receive either bare metal stents or drug-eluting stents to restore the normal blood flow. However, due to the lack of stent production with an individual patient in mind, the same level of effectiveness may not be possible in treating two different clinical scenarios. This study introduces for the first time the feasibility of a patient-specific stenting process constructed from direct 3D segmentation of medical images using direct 3D printing of biodegradable polymer-graphene composite with dual drug incorporation. A biodegradable polymer-carbon composite is prepared doped with graphene nanoplatelets to achieve controlled release of combinatorics as anticoagulation and antirestenosis agents. This study develops a technology prototyped for personalized stenting. An in silico analysis is performed to optimize the stent design for printing and its prediction of sustainability under force exerted by coronary artery or blood flow. A holistic approach covering in silico to in situ-in vivo establishes the structural integrity of the polymer composite, its mechanical properties, drug loading and release control, prototyping, functional activity, safety, and feasibility of placement in coronary artery of swine.