Adhesion and Activation of Blood Platelets on Laser-Structured Surfaces of Biomedical Metal Alloys.

The laser surface modification of metallic implants presents a promising alternative to other surface modification techniques. A total of four alloyed metallic biomaterials were used for this study: medical steel (AISI 316L), cobalt-chromium-molybdenum alloy (CoCrMo) and titanium alloys (Ti6Al4V and Ti6Al7Nb). Samples of metallic biomaterials after machining were subjected to polishing or laser modification in two different versions.

Assessment of the influence of gold nanoparticles stabilized with PAMAM dendrimers on HUVEC barrier cells.

Civilization diseases, cancer, frequent mutations of viruses and other pathogens constitute the need to look for new drugs, as well as systems for their targeted delivery. One of the promising way of using drugs is supplying them by linking to nanostructures. One of the solution for the development of nanobiomedicine are metallic nanoparticles stabilized with various polymer structures.

Investigation of HUVEC response to exposure to PAMAM dendrimers - changes in cell elasticity and vesicles release.

The aim of this study is to assess the effect of PAMAM dendrimers of second, fourth, and seventh generations on human umbilical vein endothelial cells. Primary endothelial cells were exposed to PAMAM dendrimers for 24 h, using concentrations reducing cellular viability to the levels of 90, 75, and 50%. We assumed, that changes in mechanical properties reflect toxicity of PAMAM dendrimers.

Osteosarcoma cells in early and late stages as cancer in vitro progression model for assessing the responsiveness of cells to silver nanoparticles.

Understanding of biology of osteosarcoma malignant progression is indispensable for enhancement of conventional chemotherapy by the use of silver nanoparticles (AgNPs). We presented an in vitro model of cancer progression closely resembling processes occurring in vivo in terms of protein profile. A comparison of cytotoxic and genotoxic potential of AgNPs in Saos-2 cells in early stages of cancerous progression (early passages) with the cells in advanced stages (late passages) demonstrated significantly reduced responsiveness of the late passage cells to nanoparticles toxicity.

Isolation, Biochemical Characterisation and Identification of Thermotolerant and Cellulolytic and .

Research Background: Cellulose is an ingredient of waste materials that can be converted to other valuable substances. This is possible provided that the polymer molecule is degraded to smaller particles and used as a carbon source by microorganisms. Because of the frequently applied methods of pretreatment of lignocellulosic materials, the cellulases derived from thermophilic microorganisms are particularly desirable.

Formation of Nitrogen Doped Titanium Dioxide Surface Layer on NiTi Shape Memory Alloy.

NiTi shape memory alloys are increasingly being used as bone and cardiac implants. The oxide layer of nanometric thickness spontaneously formed on their surface does not sufficiently protect from nickel transition into surrounding tissues, and its presence, even in a small amount, can be harmful to the human organism. In order to limit this disadvantageous phenomenon, there are several surface engineering techniques used, including oxidation methods.

Dysfunction of endothelial cells exposed to nanomaterials assessed by atomic force spectroscopy.

The study of the impact of nanomaterials on endothelial cell elasticity with the atomic force spectroscopy (AFS) can be a significant model for assessing nanomaterials toxic effects in vitro. The mechanical properties of cells exposed to nanostructures can provide information not only about cellular nano and micro-structure, but also about cell physiology. The toxicity of nanostructures is an important issue which must be carefully considered when the optimal nanomaterial is defined.

Comprehensive Biological Evaluation of Biomaterials Used in Spinal and Orthopedic Surgery.

Biological acceptance is one of the most important aspects of a biomaterial and forms the basis for its clinical use. The aim of this study was a comprehensive biological evaluation (cytotoxicity test, bacterial colonization test, blood platelets adhesion test and transcriptome and proteome analysis of Saos-2 cells after contact with surface of the biomaterial) of biomaterials used in spinal and orthopedic surgery, namely, Ti6Al4V ELI (Extra Low Interstitials), its modified version obtained as a result of melting by electron beam technology (Ti6Al4V ELI-EBT), polyether ether ketone (PEEK) and polished medical steel American Iron and Steel Institute (AISI) 316L (the reference material). Biological tests were carried out using the osteoblasts-like cells (Saos-2, ATCC HTB-85) and bacteria (DH5α).

Endothelial cell aging detection by means of atomic force spectroscopy.

Endothelial cell aging is related to changes not only in cell phenotype, such as luminal changes, intimal and medial thickening, and increased vascular stiffness, but encompasses different cell responses to various substances including drugs or nanomaterials. In the present work, time- and dose-dependent elasticity changes evoked by silver nanoparticles in endothelial cells in early (below 15) passages were analyzed. Silver nanoparticle concentrations of 3, 3.

Designing laser-modified surface structures on titanium alloy custom medical implants using a hybrid manufacturing technology.

The hybrid technology combines an efficient material-removal process and implant surface treatment by the laser reducing time of manufacture process compared to currently used machining technologies. It also permits precise structuring of the implant material surface. Six structures of the Ti6Al4V ELI surface were designed and studied how the structure topography prepared with the hybrid technology affected the Escherichia coli adhesion to the surface and viability, as well as the growth, adhesion, and viability of human osteogenic Saos-2 cells cultured on the investigated surfaces.

Simultaneous transcriptome and proteome analysis of EA.hy926 cells under stress conditions induced by nanomaterials.

Today, the extensive and constantly growing number of applications in the field of nanotechnology poses a lot of questions about the potential toxicity of nanomaterials (NMs) toward cells of different origins. In our work we employed the tools of molecular biology to evaluate changes that occur in human endothelial cells at the transcriptomic and proteomic level, following 24 h of exposure to three different classes of NMs. Using microarray technology, we demonstrated that 24 h of exposure to silver nanoparticles (SNPs), multiwalled carbon nanotubes (MWCNTs) and polyamidoamine dendrimers (PAMAMs) leads to changes in 299, 1271, and 431 genes, respectively, influencing specific molecular pathways.

Sensing of silver nanoparticles on/in endothelial cells using atomic force spectroscopy.

Endothelial cells, due to their location, are interesting objects for atomic force spectroscopy study. They constitute a barrier between blood and vessel tissues located deeper, and therefore they are the first line of contact with various substances present in blood, eg, drugs or nanoparticles. This work intends to verify whether the mechanical response of immortalized human umbilical vein endothelial cells (EA.

Toxicity of silver nanoparticles, multiwalled carbon nanotubes, and dendrimers assessed with multicellular organism Caenorhabditis elegans.

Nematode Caenorhabditis elegans (C. elegans) was used to investigate the impact of silver nanoparticles (SNP), multiwalled carbon nanotubes (MWCNT), and polyamidoamine dendrimers (PAMAM) used in concentration of 10 particle/mL. Population-based observations and gene expression analysis were employed in this study.

Human brain endothelial barrier cells are distinctly less vulnerable to silver nanoparticles toxicity than human blood vessel cells: A cell-specific mechanism of the brain barrier?

The blood-brain barrier (BBB) constitutes a distinctive and tightly regulated interface between the brain and the peripheral circulation. The objective of studies was to compare responses of human endothelial cells representing the model of blood vessels - EA.hy926 and HUVEC cells and the model of the brain endothelial barrier - HBEC5i cells to silver nanoparticles (SNPs).

The effect of carbon nanoparticles on biological properties of polyester nanocomposites.

The aim of present study was to determine the hemocompatibility, cellular response of endothelial cells and bacterial adhesion to a new polyester nanocomposite. The carbon nanoparticle nanocomposite was prepared via in situ polymerization of monomers to obtain material of hardness 55 Sh D similar to polyurethanes used in medical applications, for example, in heart-assisting devices. The carbon nanoparticle-containing polyester exhibits markedly reduced bacterial colonization, as compared to commercially available polyurethanes.

Radio-opaque polyethylene for personalized craniomaxillofacial implants.

Objective: This study aimed to present a new possibility to create radio-opaque implant material for craniomaxillofacial reconstruction.

Materials And Methods: The test disks made of the own compound of polyethylenes with addiction of 2, 4, and 6 % of weight TiO was investigated for cytotoxicity [each group 15 disks respectively]. Next, computed tomography of the disks was performed in environment of muscle and fat.

Early cell response to contact with biomaterial's surface.

Most biomaterials at present have sufficient mechanical properties; however compliance with standards for biocompatibility is often not sufficient in clinical practice. This may be due to the complexity of biological systems in general and the diversity of individual responses to these materials by implant recipients. Significant improvement of biocompatibility must involve surface modification of implants, which in the future will make it possible to introduce individually selected types of surface modification for individual recipients.

Proteomic analysis of proteins engaged in α-methylene-δ-lactone cytotoxic effects in hormone-independent breast cancer MDA-MB-231 cells.

A simple synthetic α-methylene-δ-lactone, 1-isopropyl-2-methylene-1,2-dihydrobenzochromen-3-one, designated DL-3, was shown previously to induce apoptosis and significantly suppress cell metastatic potential in MDA-MB-231 breast cancer cells. The mechanisms through which DL-3 exerts its effects are poorly understood. The purpose of this study was to investigate the protein expression profiles in MDA-MB-231 cells exposed to the DL-3 treatment.

Technical concept of patient-specific, ultrahigh molecular weight polyethylene orbital wall implant.

Introduction: The authors have been using patient-specific implants since 2006 and are constantly looking for new reconstructive materials, in order to create precise implants for orbital reconstruction. Such materials should be biocompatible and stable in the human body, as well as easy to machine and form into complex 3D shapes. Biocompatible ultrahigh molecular weight polyethylene (UHMW-PE) has several unique properties including high impact strength and a low friction coefficient that result in self-lubricating and thus non-sticking surfaces after processing.

Effect of uremia and hemodialysis on proteome profile of blood platelets and plasma.

The aim of the present research was to assess the differences in blood platelet and plasma proteome profiles of patients with uremia in comparison with healthy participants. It was found that 23 peptides in the platelet proteome profiles of hemodialyzed patients and only 6 peptides in nondialyzed patients were upregulated. On the other hand, 18 peptides with reduced expression in nondialyzed patients and only 1 peptide in hemodialyzed patients were found.

Effect of uremia and hemodialysis on platelet apoptosis.

The blood platelet proteome of hemodialyzed patients with uremia exhibits significant difference in comparison with the blood platelet proteome of healthy individuals. This alteration is manifested by the presence of high concentrations of low-molecular peptides within the whole range of isoelectric points. Increased platelet apoptosis has been put forward as a possible cause of this phenomenon.

Thrombocompatibility of thin dielectric carbon film dependence on electron work function of metallic substrate material.

We demonstrate here for the first time the relationship between electron work function of metallic substrate material, used for coating with thin dielectric carbon (DC) film, and surface thrombocompatybility of this structure. Thin dielectric layers of DC, with thickness below 1 microm, were deposited on medical steel 316L, titanium alloy Ti6Al4V and titanium nitride (TiN) using the RFCVD method. The values of the DC coated metallic electrode potential in water and in serum and the number of adhered blood platelets to the DC coated metals depended on the electron work function (phiM) of the metallic substrate.

Interaction of parylene C with biological objects.

The aim of the present work was to examine the interactions of parylene C with such selected biological objects as: blood plasma proteins, platelets, endothelial cells, and bacterial biofilm produced by E. coli cells. The results obtained strongly support the thesis that parylene C is a material worth considering for biomedical use.

Comparison of microscopic methods for evaluating platelet adhesion to biomaterial surfaces.

Microscopic methods usable for sample surface imaging and subsequent qualitative and quantitative evaluation of platelet adhesion to the surface of the biomaterial studied were compared. It was shown, making use of the samples of medical steel (AISI 316L), that such tools as surface imaging with scanning electron microscopy (SEM), glutaraldehyde induced fluorescence technique (GIFT) and metallurgical microscopy (MM) are equivalent in evaluating surface platelet adhesion. The importance of biological variability of blood samples for a proper result assessment and the necessity of using internal standards were also considered.

Biological activity of endomorphin and [Dmt1]endomorphin analogs with six-membered proline surrogates in position 2.

Endogenous mu-opioid receptor (MOR) selective peptides, endomorphin-1 (EM-1) and endomorphin-2 (EM-2), unlike so called 'typical opioids', are characterized by the presence of Pro(2) residue, which is a spacer connecting aromatic pharmacophoric residues. In order to investigate structural requirements for position 2, we synthesized endomorphin analogs incorporating, instead of Pro, unnatural amino acids with six-membered heterocyclic rings, such as piperidine 2-, 3- or 4-carboxylic acids (Pip, Nip and Inp, respectively). (R)-Nip residue turned out to be favourable for improving MOR affinity.