A wearable sweat biosensing device is demonstrated that stimulates sweat and continuously measures sweat ethanol concentrations at 25 s intervals, which is then correlated with blood ethanol during a >3 hour testing phase.

This work is not only significant for wearable sweat biosensing technology, but could also have broader impact for those studying topical skin products, antiperspirants, textiles and medical adhesives, nerve disorders, the effects of perspiration on skin-health, skin related diseases such as idiopathic pure sudomotor failure and hyperhidrosis, and other skin- and perspiration-related applications.

Vascular diseases are characterized by the over-proliferation and migration of aortic smooth muscle cells (SMCs), and degradation of extracellular matrix (ECM) within the vessel wall, leading to compromise in cell-cell and cell-matrix signaling pathways. Tissue engineering approaches to regulate SMC over-proliferation and enhance healthy ECM synthesis showed promise, but resulted in low crosslinking efficiency. Here, we report the benefits of exogenous nitric oxide (NO) cues, delivered from S-Nitrosoglutathione (GSNO), to cell proliferation and matrix deposition by adult human aortic SMCs (HA-SMCs) within three-dimensional (3D) biomimetic cocultures. A coculture platform with two adjacent, permeable 3D culture chambers was developed to enable paracrine signaling between vascular cells. HA-SMCs were cultured in these chambers within collagen hydrogels, either alone or in the presence of human aortic endothelial cells (HA-ECs) cocultures, and exogenously supplemented with varying GSNO dosages (0-100 nM) for 21 days. Results showed that EC cocultures stimulated SMC proliferation within GSNO-free cultures. With increasing GSNO concentration, HA-SMC proliferation decreased in the presence or absence of EC cocultures, while HA-EC proliferation increased. GSNO (100 nM) significantly enhanced the protein amounts synthesized by HA-SMCs, in the presence or absence of EC cocultures, while lower dosages (1-10 nM) offered marginal benefits. Multi-fold increases in the synthesis and deposition of elastin, glycosaminoglycans, hyaluronic acid, and lysyl oxidase crosslinking enzyme (LOX) were noted at higher GSNO dosages, and coculturing with ECs significantly furthered these trends. Similar increases in TIMP-1 and MMP-9 levels were noted within cocultures with increasing GSNO dosages. Such increases in matrix synthesis correlated with NO-stimulated increases in endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) expression within EC and SMC cultures, respectively. Results attest to the benefits of delivering NO cues to suppress SMC proliferation and promote robust ECM synthesis and deposition by adult human SMCs, with significant applications in tissue engineering, biomaterial scaffold development, and drug delivery.

Alterations in phenotype and gene expression of adult human aneurysmal smooth muscle cells by exogenous nitric oxide. AbstractAbdominal aortic aneurysms (AAA) are characterized by matrix remodeling, elastin degradation, absence of nitric oxide (NO) signaling, and inflammation, influencing smooth muscle cell (SMC) phenotype and genotype. Little is known about the biomolecular release and intrinsic biomechanics of human AAA-SMCs. NO delivery could be an attractive therapeutic strategy to restore lost functionality of AAA-SMCs by inhibiting inflammation and cell stiffening. We aim to establish the differences in phenotype and genotype of adult human AAA-SMCs from healthy SMCs. Based on our previous study which showed benefits of optimal NO dosage delivered via S-Nitrosoglutathione (GSNO) to healthy aortic SMCs, we tested whether such benefits would occur in AAA-SMCs. The mRNA expression of three genes involved in matrix degradation (ACE, ADAMTS5 and ADAMTS8) was significantly downregulated in AAA-SMCs. Total protein and glycosaminoglycans synthesis were higher in AAA-SMCs than healthy-SMCs and was enhanced by GSNO and 3D cultures. Elastin gene expression, synthesis and deposition, desmosine crosslinker levels, and lysyl oxidase (LOX) functional activity were lower, while cell proliferation, iNOS, LOX and fibrillin-1 gene expressions were higher in AAA-SMCs, with differential benefits from GSNO exposure. GSNO and 3D cultures reduced MMPs -2, -9, and increased TIMP-1 release in AAA-SMC cultures. AAA-SMCs were inherently stiffer and had smoother surface than healthy SMCs, but GSNO reduced stiffness (~25%) and increased roughness of both cell types. In conclusion, exogenously-delivered NO offers an attractive strategy by providing therapeutic benefits to AAA-SMCs.We hereby submit our manuscript titled, "Improvement of altered phenotype and genotype of adult human aneurysmal smooth muscle cells by exogenous nitric oxide" to be considered for publication in the Nitric Oxide journal as an original full-length article. All authors have read and agreed with the submission of the manuscript to this journal. This manuscript hasn't been submitted or published elsewhere, either in part or in full. Novelty of this work:It is known that the pathogenesis of aortic aneurysms leads to extracellular matrix degradation in blood vessels and disruption of vascular smooth muscle cell (SMC) interactions with endothelium and medial elastic fibers. In this work, we report for the first time, on the basal amounts of numerous matrix proteins synthesized and released by aortic aneurysmal SMCs derived from LILAS (Lille Aneurysmal Study in France) patients, changes in their phenotype and genotype, the cytokines/ chemokines/ growth factors they release, and their intrinsic biophysical characteristics (cell stiffness and surface roughness). In addition, we compared such outcomes from aneurysmal cells to SMCs derived from healthy humans. Finally, we report on the benefits of delivering exogenous nitric oxide cues to restore some of these lost biophy...

With the device integration of sweat stimulation, sweat becomes a stronger candidate for non-invasive continuous biochemical sensing. However, sweat stimulants are cholinergenic agents and non-selective to just the sweat glands, and so, direct placement of sweat stimulants poses additional challenges in the possibility for uncontrollable transport of the stimulant into the body and challenges in contamination of the sweat sample. Reported here is membrane isolation of repeated-use sweat stimulants for mitigating direct dermal contact, dilution of the sweat stimulant, and contamination of the sweat sample. The membrane dramatically reduces passive diffusion of the sweat stimulant carbachol by roughly two orders of magnitude, while still allowing repeated sweat stimulation by iontophoretic delivery of the carbachol through the membrane and into the skin. Both in-vivo and in-vitro validation reveal feasibility for reliable integration of sweat stimulants within a wearable device for use periods of 24 h or more. In addition, advanced topics and confounding issues such as stimulant gel design, osmotic pressure, and ionic impurities are speculatively and theoretically discussed.