Age-related changes in the biochemical composition of the human aorta and their correlation with the delamination strength.

Various studies have correlated the mechanical properties of the aortic wall with its biochemical parameters and inner structure. Very few studies have addressed correlations with the cohesive properties, which are crucial for understanding fracture phenomena such as aortic dissection, i.e.

Comparative Study of the Dehydrothermal Crosslinking of Electrospun Collagen Nanofibers: The Effects of Vacuum Conditions and Subsequent Chemical Crosslinking.

Collagen nanofibrous materials have become integral to tissue engineering due to their exceptional properties and biocompatibility. Dehydrothermal crosslinking (DHT) enhances stability and maintains structural integrity without the formation of toxic residues. The study involved the crosslinking of electrospun collagen, applying DHT with access to air and under vacuum conditions.

Qualitative and quantitative analysis of lipid droplets in mature 3T3-L1 adipocytes using oil red O.

By differentiating into mature adipocytes, 3T3-L1 cells can be utilized as a model cell line to investigate (pre)adipocyte function in vitro. Here, we present a protocol for combining qualitative and quantitative analysis of lipid droplets in mature 3T3-L1 adipocytes using oil red O. We describe steps to differentiate 3T3-L1 preadipocytes to adipocytes and give detailed procedures to determine total lipid amount as well as lipid droplet size and number using microscopic devices and an ImageJ macro.

Titanium-Doped Diamond-like Carbon Layers as a Promising Coating for Joint Replacements Supporting Osteogenic Differentiation of Mesenchymal Stem Cells.

Diamond-like carbon (DLC) layers are known for their high corrosion and wear resistance, low friction, and high biocompatibility. However, it is often necessary to dope DLC layers with additional chemical elements to strengthen their adhesion to the substrate. Ti-DLC layers (doped with 0.

Photon-counting CT using multi-material decomposition algorithm enables fat quantification in the presence of iron deposits.

Purpose: A new generation of CT detectors were recently developed with the ability to measure individual photon's energy and thus provide spectral information. The aim of this work was to assess the performance of simultaneous fat and iron quantification using a clinical photon-counting CT (PCCT) and its comparison to dual-energy CT (DECT), MRS and MRI at 3 T.

Methods: Two 3D printed cylindrical phantoms with 32 samples (n = 12 fat fractions between 0 % and 100 %, n = 20 with mixtures of fat and iron) were scanned with PCCT and DECT scanners for comparison.

Exploring the influence of placing bi-directional E-glass fibers as protective layer under a CAD-CAM resin composite on the fracture pattern.

Objectives: To investigate the influence of the presence and position of bidirectional E-glass fibers under a CAD-CAM resin composite on the fracture pattern evaluated both after quasi-static mechanical loading and after fatigue.

Methods: Rectangular specimens (10 mm-long, 5 mm-large and 4.2 mm-thick) were prepared and divided into four groups (n = 30/group).

The electron beam irradiation of collagen in the dry and gel states: The effect of the dose and water content from the primary to the quaternary levels.

The aim of our study was to describe the impact of collagen in the gel and dry state to various doses of electron beam radiation (1, 10 and 25 kGy) which are using for food processing and sterilization. The changes in the chemical compositions (water, amino acids, lipids, glycosaminoglycans) were analyzed and the changes in the structure (triple-helix or β-sheet, the integrity of the collagen) were assessed. Subsequently, the impact of the applied doses on the mechanical properties, stability in the enzymatic environment, swelling and morphology were determined.

Properties of Bovine Collagen as Influenced by High-Pressure Processing.

The physical properties and structure of collagen treated with high-pressure technologies have not yet been investigated in detail. The main goal of this work was to determine whether this modern gentle technology significantly changes the properties of collagen. High pressure in the range of 0-400 MPa was used, and the rheological, mechanical, thermal, and structural properties of collagen were measured.

The investigation of batch-to-batch variabilities in the composition of isolates from fish and mammalian species using different protocols.

The aim of this study was to investigate batch-to-batch inconsistencies in the processing of pig and fish collagen isolates processed using two protocols that differed in terms of the acetic acid concentrations applied and the pre- and post-extraction steps, and which were previously tested in our laboratory with the intention of preserving the biological structures and functions of the collagen isolates for biomedical purposes. Both the major and minor components such as the amino acids, lipids, water, glycosaminoglycan and ash contents and elemental content, as well as the structure and morphology of the raw sources and the resulting batches of isolates were subsequently examined in detail applying standardized analytical methods including high perfomance liquid chromatography, ultraviolet-visible and infrared spectrometry, polyacrylamide gel electrophoresis, energy dispersive spectroscopy and scanning electron microscopy. All the fish isolates provided severalfold higher yields (8-45 wt%) than did the pig isolates (3-9 wt%).

Adipose-Derived Stem Cells in Reinforced Collagen Gel: A Comparison between Two Approaches to Differentiation towards Smooth Muscle Cells.

Scaffolds made of degradable polymers, such as collagen, polyesters or polysaccharides, are promising matrices for fabrication of bioartificial vascular grafts or patches. In this study, collagen isolated from porcine skin was processed into a gel, reinforced with collagen particles and with incorporated adipose tissue-derived stem cells (ASCs). The cell-material constructs were then incubated in a DMEM medium with 2% of FS (DMEM_part), with added polyvinylalcohol nanofibers (PVA_part sample), and for ASCs differentiation towards smooth muscle cells (SMCs), the medium was supplemented either with human platelet lysate released from PVA nanofibers (PVA_PL_part) or with TGF-β1 + BMP-4 (TGF + BMP_part).

Experimental surgery as part of the development of degradable biomaterials for cardiovascular surgery.

Introduction: Cardiovascular diseases are responsible for significant morbidity and mortality in the population. Artificial vascular grafts are often essential for surgical procedures in radical or palliative treatment. Many new biodegradable materials are currently under development.

Correlation between age, location, orientation, loading velocity and delamination strength in the human aorta.

Aortic dissection is a biomechanical phenomenon associated with a failure of internal cohesion, which manifests itself through the delamination of the aortic wall. The goal of this study is to deepen our knowledge of the delamination strength of the aorta. To achieve this, 661 peeling experiments were carried out with strips of the human aorta collected from 46 cadavers.

Micro-computed tomography evaluation of bone architecture in various forms of unilateral condylar hyperplasia.

Condylar hyperplasia is one of the causes of facial asymmetry and malocclusion, characterized by enlargement of the lower jaw due to excessive condyle growth activity. The aim of this study was to use micro-computed tomography (micro-CT) to evaluate the bone architecture of the condylar head and determine whether there are differences between patients with various forms of unilateral condylar hyperplasia (UCH): hemimandibular hyperplasia, elongation, and mixed form. The cohort consisted of 28 patients with a mean age of 21.

Translating the force-mechano-sensing GPCRs.

Incorporating mechanical cues into cellular responses allows us to experience our direct environment. Specialized cells can perceive and discriminate between different physical properties such as level of vibration, temperature, or pressure. Mechanical forces are abundant signals that also shape general cellular responses such as cytoskeletal rearrangement, differentiation, or migration and contribute to tissue development and function.

Evaluating the feasibility of Cas9 overexpression in 3T3-L1 cells for generation of genetic knock-out adipocyte cell lines.

Cell lines recapitulating physiological processes can represent alternatives to animal or human studies. The 3T3-L1 cell line is used to mimic adipocyte function and differentiation. Since transfection of 3T3-L1 cells is difficult, we used a modified 3T3-L1 cell line overexpressing Cas9 for a straightforward generation of gene knock-outs.

Various Simulated Body Fluids Lead to Significant Differences in Collagen Tissue Engineering Scaffolds.

This study aims to point out the main drawback with respect to the design of simulated body environments. Three media commonly used for the simulation of the identical body environment were selected, i.e.

The relevance of adhesion G protein-coupled receptors in metabolic functions.

G protein-coupled receptors (GPCRs) modulate a variety of physiological functions and have been proven to be outstanding drug targets. However, approximately one-third of all non-olfactory GPCRs are still orphans in respect to their signal transduction and physiological functions. Receptors of the class of Adhesion GPCRs (aGPCRs) are among these orphan receptors.

Lumbar Interbody Fusion Conducted on a Porcine Model with a Bioresorbable Ceramic/Biopolymer Hybrid Implant Enriched with Hyperstable Fibroblast Growth Factor 2.

Many growth factors have been studied as additives accelerating lumbar fusion rates in different animal models. However, their low hydrolytic and thermal stability both in vitro and in vivo limits their workability and use. In the proposed work, a stabilized vasculogenic and prohealing fibroblast growth factor-2 (FGF2-STAB) exhibiting a functional half-life in vitro at 37 °C more than 20 days was applied for lumbar fusion in combination with a bioresorbable scaffold on porcine models.

Vancomycin-Loaded Collagen/Hydroxyapatite Layers Electrospun on 3D Printed Titanium Implants Prevent Bone Destruction Associated with Infection and Enhance Osseointegration.

The aim of the study was to develop an orthopedic implant coating in the form of vancomycin-loaded collagen/hydroxyapatite layers (COLHA+V) that combine the ability to prevent bone infection with the ability to promote enhanced osseointegration. The ability to prevent bone infection was investigated employing a rat model that simulated the clinically relevant implant-related introduction of bacterial contamination to the bone during a surgical procedure using a clinical isolate of . The ability to enhance osseointegration was investigated employing a model of a minipig with terminated growth.

Determination of glycosaminoglycans in biological matrices using a simple and sensitive reversed-phase HPLC method with fluorescent detection.

This paper suggests a sensitive reversed-phase gradient HPLC method combined with fluorescence detection that has been developed, optimized and tested via the quantitative analysis of authentic biological material in an effort to determine and subsequently compare the total content of glycosaminoglycans (GAGs) in various collagen-based biomaterials intended for medical application. The proposed analytical method enabled the identification and separation of the GAGs present from the other components in the samples using commonly-available laboratory equipment; moreover, the very low detection limit of the method permits the determination of GAGs even for very small samples. This study describes the development of the method, including the isolation and processing of the collagen samples prior to HPLC analysis and the optimal parameters applied during the chromatographic analysis.

Effect of diamond-like carbon doped with chromium on cell differentiation, immune activation and apoptosis.

Diamond-like carbon (DLC) is a biocompatible material that has many potential biomedical applications, including in orthopaedics. DLC layers doped with Cr at atomic percent (at.%) of 0, 0.

Rifampin-Releasing Triple-Layer Cross-Linked Fresh Water Fish Collagen Sponges as Wound Dressings.

Objectives: Surgical wounds resulting from biofilm-producing microorganisms represent a major healthcare problem that requires new and innovative treatment methods. Rifampin is one of a small number of antibiotics that is able to penetrate such biofilms, and its local administration has the potential to serve as an ideal surgical site infection protection and/or treatment agent. This paper presents two types (homogeneous and sandwich structured) of rifampin-releasing carbodiimide-cross-linked fresh water fish collagen wound dressings.

The repertoire of Adhesion G protein-coupled receptors in adipocytes and their functional relevance.

Background: G protein-coupled receptors (GPCR) are well-characterized regulators of a plethora of physiological functions among them the modulation of adipogenesis and adipocyte function. The class of Adhesion GPCR (aGPCR) and their role in adipose tissue, however, is poorly studied. With respect to the demand for novel targets in obesity treatment, we present a comprehensive study on the expression and function of this enigmatic GPCR class during adipogenesis and in mature adipocytes.

Peptide mass mapping in bioapatites isolated from animal bones.

Bioapatite ceramics produced from biogenic sources provide highly attractive materials for the preparation of artificial replacements since such materials are not only more easily accepted by living organisms, but bioapatite isolated from biowaste such as xenogeneous bones also provides a low-cost material. Nevertheless, the presence of organic compounds in the bioapatite may lead to a deterioration in its quality and may trigger an undesirable immune response. Therefore, procedures which ensure the elimination of organic compounds through bioapatite isolation are being subjected to intense investigation and the presence of remaining organic impurities is being determined through the application of various methods.

Surface Treatment of Acetabular Cups with a Direct Deposition of a Composite Nanostructured Layer Using a High Electrostatic Field.

A composite nanofibrous layer containing collagen and hydroxyapatite was deposited on selected surface areas of titanium acetabular cups. The layer was deposited on the irregular surface of these 3D objects using a specially developed electrospinning system designed to ensure the stability of the spinning process and to produce a layer approximately 100 micrometers thick with an adequate thickness uniformity. It was verified that the layer had the intended nanostructured morphology throughout its entire thickness and that the prepared layer sufficiently adhered to the smooth surface of the model titanium implants even after all the post-deposition sterilization and stabilization treatments were performed.