scholarly journals Recent Impact of Microfluidics on Skin Models for Perspiration Simulation

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 150
Author(s):  
Genís Rabost-Garcia ◽  
Josep Farré-Lladós ◽  
Jasmina Casals-Terré

Skin models offer an in vitro alternative to human trials without their high costs, variability, and ethical issues. Perspiration models, in particular, have gained relevance lately due to the rise of sweat analysis and wearable technology. The predominant approach to replicate the key features of perspiration (sweat gland dimensions, sweat rates, and skin surface characteristics) is to use laser-machined membranes. Although they work effectively, they present some limitations at the time of replicating sweat gland dimensions. Alternative strategies in terms of fabrication and materials have also showed similar challenges. Additional research is necessary to implement a standardized, simple, and accurate model representing sweating for wearable sensors testing.

Author(s):  
Andrie G. Panayiotou ◽  
Evangelos D. Protopapadakis

Wearable and mobile technology has advanced in leaps and bounds in the last decade with technological advances creating a role from enhancing healthy living to monitoring and treating disease. However, the discussion about the ethical use of such commercial technology in the community, especially in minors, is lacking behind. In this paper, we first summarize the major ethical concerns that arise from the usage of commercially available wearable technology in children, with a focus on smart watches, highlighting issues around the consent process, mitigation of risk and potential confidentiality and privacy issues, as well as the potential for therapeutic misconceptions when used without medical advice. Then through a relevant thought experiment we move on to outline some further ethical concerns that are connected to the use of wearables by minors, to wit the issue of informed consent in the case of minors, forcing them to live in the spotlight, and compromising their right to an open future. We conclude with the view that mitigating potential pitfalls and enhancing the benefits of wearable technology especially for minors requires brave and comprehensive moral debates.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 473
Author(s):  
Dilyana Gospodonova ◽  
Iliana Ivanova ◽  
Todorka Vladkova

The aim of this study was to prepare TiO2/Ag/Cu magnetron co-sputtered coatings with controlled characteristics and to correlate them with the antimicrobial activity of the coated glass samples. The elemental composition and distribution, surface morphology, wettability, surface energy and its component were estimated as the surface characteristics influencing the bioadhesion. Well expressed, specific, Ag/Cu concentration-dependent antimicrobial activity in vitro was demonstrated toward Gram-negative and Gram-positive standard test bacterial strains both by diffusion 21 assay and by Most Probable Number of surviving cells. Direct contact and eluted silver/coper nanoparticles killing were experimentally demonstrated as a mode of the antimicrobial action of the studied TiO2/Ag/Cu thin composite coatings. It is expected that they would ensure a broad spectrum bactericidal activity during the indwelling of the coated medical devices and for at least 12 h after that, with the supposition that the benefits will be over a longer time.


Biofilm ◽  
2021 ◽  
pp. 100047
Author(s):  
Snehal Kadam ◽  
Vandana Madhusoodhanan ◽  
Radhika Dhekane ◽  
Devyani Bhide ◽  
Rutuja Ugale ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1913
Author(s):  
Luminita Nicoleta Dumitrescu ◽  
Madalina Icriverzi ◽  
Anca Bonciu ◽  
Anca Roșeanu ◽  
Antoniu Moldovan ◽  
...  

In the last decades, optimizing implant properties in terms of materials and biointerface characteristics represents one of the main quests in biomedical research. Modifying and engineering polyvinylidene fluoride (PVDF) as scaffolds becomes more and more attractive to multiples areas of bio-applications (e.g., bone or cochlear implants). Nevertheless, the acceptance of an implant is affected by its inflammatory potency caused by surface-induced modification. Therefore, in this work, three types of nano-micro squared wells like PVDF structures (i.e., reversed pyramidal shape with depths from 0.8 to 2.5 microns) were obtained by replication, and the influence of their characteristics on the inflammatory response of human macrophages was investigated in vitro. FTIR and X-ray photoelectron spectroscopy analysis confirmed the maintaining chemical structures of the replicated surfaces, while the topographical surface characteristics were evaluated by AFM and SEM analysis. Contact angle and surface energy analysis indicated a modification from superhydrophobicity of casted materials to moderate hydrophobicity based on the structure’s depth change. The effects induced by PVDF casted and micron-sized reversed pyramidal replicas on macrophages behavior were evaluated in normal and inflammatory conditions (lipopolysaccharide treatment) using colorimetric, microscopy, and ELISA methods. Our results demonstrate that the depth of the microstructured surface affects the activity of macrophages and that the modification of topography could influence both the hydrophobicity of the surface and the inflammatory response.


2009 ◽  
Vol 20 (8) ◽  
pp. 2276-2285 ◽  
Author(s):  
Blanca Schafer ◽  
Joel Quispe ◽  
Vineet Choudhary ◽  
Jerry E. Chipuk ◽  
Teddy G. Ajero ◽  
...  

Mitochondrial outer membrane permeabilization (MOMP) is a critical step in apoptosis and is regulated by Bcl-2 family proteins. In vitro systems using cardiolipin-containing liposomes have demonstrated the key features of MOMP induced by Bax and cleaved Bid; however, the nature of the “pores” and how they are formed remain obscure. We found that mitochondrial outer membranes contained very little cardiolipin, far less than that required for liposome permeabilization, despite their responsiveness to Bcl-2 family proteins. Strikingly, the incorporation of isolated mitochondrial outer membrane (MOM) proteins into liposomes lacking cardiolipin conferred responsiveness to cleaved Bid and Bax. Cardiolipin dependence was observed only when permeabilization was induced with cleaved Bid but not with Bid or Bim BH3 peptide or oligomerized Bax. Therefore, we conclude that MOM proteins specifically assist cleaved Bid in Bax-mediated permeabilization. Cryoelectron microscopy of cardiolipin-liposomes revealed that cleaved Bid and Bax produced large round holes with diameters of 25–100 nm, suggestive of lipidic pores. In sum, we propose that activated Bax induces lipidic pore formation and that MOM proteins assist cleaved Bid in this process in the absence of cardiolipin.


Author(s):  
Christo J. Botha ◽  
Sarah J. Clift ◽  
Gezina C.H. Ferreira ◽  
Mxolisi G. Masango

Geigeria poisoning in sheep, locally known as ‘vermeersiekte’, is an economically important plant poisoning in southern Africa. The toxic principles contained by the toxic plants are believed to be several sesquiterpene lactones, such as geigerin, vermeeric acid and vermeerin, which cause striated muscle lesions in small stock. Because of ethical issues surrounding the use of live animals in toxicity studies, there is currently a dire need to establish an in vitro model that can be used to replace traditional animal experimentation. The objective of this study was to determine the cytotoxicity of geigerin in a murine myoblast cell line (C2C12) using methyl-thiazol-tetrazolium (MTT) and lactate dehydrogenase (LDH) assays, annexin V and propidium iodide (PI) flow cytometry and transmission electron microscopy (TEM). Mouse myoblasts were exposed to 2.0 mM, 2.5 mM and 5.0 mM geigerin for 24, 48 and 72 h. A concentration-dependent cytotoxic response was observed. Apoptosis was detected by means of annexin V flow cytometry during the first 24 h and apoptotic bodies were also visible on TEM. According to the LDH and PI flow cytometry results, myoblast cell membranes were not injured. We concluded that the murine myoblast cell line (C2C12) is a suitable model for future studies planned to evaluate the cytotoxicity of other and combinations of sesquiterpene lactones, with and without metabolic activation, implicated in ‘vermeersiekte’ and to elucidate the subcellular effects of these myotoxins on cultured myoblasts.


Metabolites ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 700
Author(s):  
Yohannes Abere Ambaw ◽  
Martin P. Pagac ◽  
Antony S. Irudayaswamy ◽  
Manfred Raida ◽  
Anne K. Bendt ◽  
...  

Malassezia are common components of human skin, and as the dominant human skin eukaryotic microbe, they take part in complex microbe–host interactions. Other phylogenetically related fungi (including within Ustilagomycotina) communicate with their plant host through bioactive oxygenated polyunsaturated fatty acids, generally known as oxylipins, by regulating the plant immune system to increase their virulence. Oxylipins are similar in structure and function to human eicosanoids, which modulate the human immune system. This study reports the development of a highly sensitive mass-spectrometry-based method to capture and quantify bioactive oxygenated polyunsaturated fatty acids from the human skin surface and in vitro Malassezia cultures. It confirms that Malassezia are capable of synthesizing eicosanoid-like lipid mediators in vitro in a species dependent manner, many of which are found on human skin. This method enables sensitive identification and quantification of bioactive lipid mediators from human skin that may be derived from metabolic pathways shared between skin and its microbial residents. This enables better cross-disciplinary and detailed studies to dissect the interaction between Malassezia and human skin, and to identify potential intervention points to promote or abrogate inflammation and to improve human skin health.


2014 ◽  
Vol 5 (2) ◽  
pp. 81-86
Author(s):  
Hossam A Eid ◽  
Khalid M Abdelaziz ◽  
Refaat A Eid

ABSTRACT Objective Advanced glycosylated end products (AGEs) in type II diabetic patients are usually precipitated on the periodontallyaffected root surfaces. The presence of periodontopathic microbes, at the same time, may also add a negative impact on the prognosis of the regenerative periodontal surgery. This in vitro study aimed to evaluate the effect of chemical conditioning on surface characteristics of periodontally-affected roots of diabetic patients. Methods Three groups (n = 25) of freshly-extracted teeth were collected from the outpatient clinics, College of Dentistry, King Khalid University. In group 1, teeth were collected from healthy individuals for orthodontic purpose. Teeth of group 2 were collected from healthy patients with chronic periodontitis, while those of group 3 were collected from diabetic patients with chronic periodontitis. Roots of the collected teeth were examined using the scanning electron microscope (SEM) before and after mechanical surface planning and chemical treatment using normal saline, EDTA gel, Tetracycline HCL (TC) or citric acid (CA) each for 4 minutes (n = 5 from each group). Results Interpretation of SEM images revealed undesirable etching effect of the chemicals used on the surfaces of healthy roots. Although EDTA showed an effective cleanse of the smear debris, it seemed to have no power on surface cuticles existed on roots of diabetic individuals. Tetracycline HCl provided acceptable conditioning of periodontally-affected root surfaces. Citric acid showed a powerful removal of both smear debris and cuticle layers off the periodontally-affected roots of diabetic individuals. Conclusion Topical application of EDTA, TC or CA shows sensible effect on the periodontally affected root surfaces. However, each of these chemicals exhibits different conditioning power. Citric acid is a promising agent to biomodify the periodontally-affected root surfaces of diabetic patients. Clinical relevance Citric acid is an acceptable biomodifier for the periodontally-affected root surfaces. This approach may improve the prognosis of periodontal therapies especially in type II diabetic patients. How to cite this article Abdelaziz KM, Eid HA, Eid RA. Effect of Bioconditioning on Surface Characteristics of Periodontally- affected Roots of Diabetic Patients. World J Dent 2014;5(2):81-86.


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