Auxetic cardiac patches with tunable mechanical and conductive properties toward treating myocardial infarction

An auxetic conductive cardiac patch (AuxCP) for the treatment of myocardial infarction (MI) is introduced. The auxetic design gives the patch a negative Poisson's ratio, providing it with the ability to conform to the demanding mechanics of the heart. The conductivity allows the patch to interface with electroresponsive tissues such as the heart. Excimer laser microablation is used to micropattern a re-entrant honeycomb (bow-tie) design into a chitosan-polyaniline composite. It is shown that the bow-tie design can produce patches with a wide range in mechanical strength and anisotropy, which can be tuned to match native heart tissue. Further, the auxetic patches are conductive and cytocompatible with murine neonatal cardiomyocytes in vitro. Ex vivo studies demonstrate that the auxetic patches have no detrimental effect on the electrophysiology of both healthy and MI rat hearts and conform better to native heart movements than unpatterned patches of the same material. Finally, the AuxCP applied in a rat MI model results in no detrimental effect on cardiac function and negligible fibrotic response after two weeks in vivo. This approach represents a versatile and robust platform for cardiac biomaterial design and could therefore lead to a promising treatment for MI

The authority of the published memoir: Laying the path for the creation of the Expatriate Archive Centre

The pursuit of a work opportunity is the least dramatic reason for migration, especially when organized as an assignment. This notion denotes a pre-decided temporariness, which is the main characteristic of the expatriate as a person in migration. The temporariness though may have a span of two years or a decade, and sometimes more, which means that a considerable chunk of life is involved; concerning the persons holding the assignment as much as the people close to them. Who is this people, how do they spend their days, with whom they connect, what do they think of their temporary home and of their own home country seen from a distance, how do they feel being alienated from their habits and their culture? These are topics of interest flowing among the expatriates’ communities around the world, rarely finding a ground outside this circle. Recognizing the problem in their own environment, a group of women, identifying themselves as ‘Shell wives’, took the initiative to document the lives of the expatriates. Their project, exceeding their initial aspirations, led to the creation of a center of research for the position of expatriates in global migration: the Expatriate Archive Centre

Conductive biomaterials with an auxetic design for treating Myocardial infarction

Myocardial infarction (MI) is responsible for millions of deaths every year worldwide. Biomaterials and regenerative therapies may have the capacity to treat this disease. Conjugated polymers are of particular interest for treating MIs, primarily for their potential ability to improve signal transduction and reduce arrhythmias that occur in the insulating fibrotic tissue that forms following an MI. However, such materials need further optimisation to be applicable as a cardiac patch. Herein the need for improved mechanical properties, particularly the magnitude and anisotropy of effective stiffness, is addressed by the auxetic micropatterning of a cardiac patch. Auxetic materials are those with a negative Poisson’s ratio, they expand laterally when stretched longitudinally and have the potential to enhance biomaterial conformability. High precision micropatterning into a chitosan-polyaniline composite was achieved through excimer laser microablation. This produces a repeating, re-entrant honeycomb design with scalable feature sizes (20 to 480 µm). Tensile tests show that the magnitude (E: 140 ± 40 kPa to 2.8 ± 0.5 MPa) and anisotropic ratio of the effective stiffnesses (EY/EX: 0.8 to 5.6) can be tuned to match the values of the native heart by modifying pattern dimensions. These auxetic cardiac patches display conductivity (10-2 S/cm) and cytocompatibility. Consequently, ex vivo studies found that the auxetic cardiac patches had no detrimental effect on the electrophysiology of both healthy and MI native rat heart tissue. In addition, a biomechanical rig was designed and built to enable a novel ex vivo technique, which has shown that patterning the patches improves their conformability to native heart tissue movements. Most notably, the work in this thesis describes a versatile and sophisticated method to control and tune the mechanical properties of a biomaterial, whilst maintaining the bulk properties of the material. This in turn could lead to improved biomaterial design for treating MIs.Open Acces

Type 2 diabetes mellitus management in patients with chronic kidney disease: an update

Diabetes mellitus (DM) is a chronic multisystem disease. Diabetic nephropathy (DN) is one of its significant microvascular complications, associated with increased morbidity and mortality. The aim of this article is to review the literature regarding the latest advances in the management of type 2 DM (T2DM) in patients with chronic kidney disease (CKD). We initially refer to the screening guidelines, the diagnostic tests used, the need for novel biomarkers in DN, the recent advances in high-risk patient identification, the recommended glycemic targets, and concerns regarding the accuracy of HbA1c in these patients. Then, a detailed explanation of the appropriate medical management based on evidence from recent trials is presented, analyzed, and discussed. All patients with T2DM should be screened for albuminuria at initial diagnosis and annually thereafter. Proteomics and metabolomics today represent promising diagnostic tools. Optimal glycemic control, with individualized HbA1c targets, is fundamental for reduced onset or delayed progression of DN and microvascular complications, in general. This can be enhanced by lifestyle modifications and pharmacological interventions when needed. Metformin represents the first pharmacological step, with, recently, a broadened indication for patients with impaired renal function. If HbA1c remains above the target in patients with established CKD, SGLT2i or GLP-1 RA are the preferred second-line agents, as introduced in all new guidelines. This change was the result of recent landmark trials that highlighted the superiority of the two aforementioned medication categories in terms of both renal and cardiovascular outcomes. © 2020, Hellenic Endocrine Society

Research data supporting "Engineering anisotropic muscle tissue using acoustic cell patterning"

Raw research data supporting the publication: Armstron, JPK et al., "Engineering anisotropic muscle tissue using acoustic cell paterning", Advanced Materials, DOI: 10.1002/adma.201802649 (2018