MatriGrid® Based Biological Morphologies: Tools for 3D Cell Culturing.

Recent trends in 3D cell culturing has placed organotypic tissue models at another level. Now, not only is the microenvironment at the cynosure of this research, but rather, microscopic geometrical parameters are also decisive for mimicking a tissue model. Over the years, technologies such as micromachining, 3D printing, and hydrogels are making the foundation of this field. However, mimicking the topography of a particular tissue-relevant substrate can be achieved relatively simply with so-called template or morphology transfer techniques. Over the last 15 years, in one such research venture, we have been investigating a micro thermoforming technique as a facile tool for generating bioinspired topographies. We call them MatriGrid®s. In this research account, we summarize our learning outcome from this technique in terms of the influence of 3D micro morphologies on different cell cultures that we have tested in our laboratory. An integral part of this research is the evolution of unavoidable aspects such as possible label-free sensing and fluidic automatization. The development in the research field is also documented in this account.

Donor-acceptor Stenhouse adduct-grafted polycarbonate surfaces: selectivity of the reaction for secondary amine on surface.

Donor-acceptor Stenhouse adducts (DASAs) are gaining attention from organic and material chemists due to their visible light-stimulated photochromic properties. In this report, we present a facile method for grafting coloured triene on polycarbonate surface, without involving any pre-treatments like plasma activation, etc. The chemoselectivity of carbonate with a primary amine and Meldrum's activated furan (MAF) with polymer bound secondary amine has been exploited to graft photoswitchable DASA on the polymer surface. Primary, secondary and tertiary amine-functionalized polycarbonate surfaces have been prepared to evaluate the reactivity of amine with MAF.

3D Microcontact Printing for Combined Chemical and Topographical Patterning on Porous Cell Culture Membrane.

Micrometer-scale biochemical or topographical patterning is commonly used to guide the cell attachment and growth, but the ability to combine these patterns into an integrated surface with defined chemical and geometrical characteristics still remains a technical challenge. Here, we present a technical solution for simultaneous construction of 3D morphologies, in the form of channels, on porous membranes along with precise transfer of extracellular matrix proteins into the channels to create patterns with geometrically restricting features. By combining the advantages of microthermoforming and microcontact printing, this technique offers a unique patterning process that provides spatiotemporal control over morphological and chemical feature in a single step. By use of our 3D-microcontact printing (3DµCP), determined microstructures like channels with different depths and widths even with more complex patterns can be fabricated. Collagen, fibronectin, and laminin were successfully transferred inside the predesigned geometries, and the validity of the process was confirmed by antibody staining. Cells cultivated on 3DµCP patterned polycarbonate membrane have shown selective adhesion and growth. This technique offers a novel tool for creating freeform combinatorial patterning on the thermoformable surface.

Assessment of Subclinical Atherosclerosis Using Computed Tomography Calcium Scores in Patients with Familial and Nonfamilial Hypercholesterolemia.

AIM: The aim of this study was to compare coronary calcium scores and aortic calcium scores between patients with severe hypercholesterolemia having a DNA-based diagnosis of FH (FH group) versus patients with severe hypercholesterolemia without the FH gene mutation (NFH group). METHOD: A total of 89 FH and 50 NFH patients underwent CT with coronary and thoracic aorta calcium scoring. Their CCS and TCS in ascending aorta (TCSasc) and descending aorta (TCSdesc) were determined and compared between the two patient groups. RESULTS: TCSasc was significantly higher in the FH group when compared to the NFH group (30.6± 59 vs 4.7±13.4, p＜0.001. After adjusting for age, sex, smoking, blood pressure, history of diabetes mellitus and LDL cholesterol levels, FH gene mutation was an independent risk factor of having non-zero TCSasc 3.6 (95% CI, 1.4-9.5, p＜0.01), high TCSasc 9.6 (95% CI, 2.4-38.2, p＜0.01) and high CCS of 4.1 (95% CI, 1.2-13.2. p＜0.05). CONCLUSION: We found that when computed tomography calcium scores were used as an assessment, patients with familial hypercholesterolemia displayed an increased burden of ascending aorta atherosclerosis when compared to patients with nonfamilial severe hypercholesterolemia. This phenomenon appears to be more dependent on the presence of FH genotype than hypercholesterolemia itself.

Thermoforming techniques for manufacturing porous scaffolds for application in 3D cell cultivation.

Within the scientific community, there is an increasing demand to apply advanced cell cultivation substrates with increased physiological functionalities for studying spatially defined cellular interactions. Porous polymeric scaffolds are utilized for mimicking an organ-like structure or engineering complex tissues and have become a key element for three-dimensional (3D) cell cultivation in the meantime. As a consequence, efficient 3D scaffold fabrication methods play an important role in modern biotechnology. Here, we present a novel thermoforming procedure for manufacturing porous 3D scaffolds from permeable materials. We address the issue of precise thermoforming of porous polymer foils by using multilayer polymer thermoforming technology. This technology offers a new method for structuring porous polymer foils that are otherwise available for non-porous polymers only. We successfully manufactured 3D scaffolds from solvent casted and phase separated polylactic acid (PLA) foils and investigated their biocompatibility and basic cellular performance. The HepG2 cell culture in PLA scaffold has shown enhanced albumin secretion rate in comparison to a previously reported polycarbonate based scaffold with similar geometry.