clay and Hemolysis

We present here preparation of mechanically strong and biocompatible cryogel composites based on hyaluronic acid (HA) and halloysite nanotubes (HNTs) of various compositions, and their applications as scaffold for different cell growing media. Uniaxial compression tests reveal that the incorporation of HNTs into HA cryogels leads to a ~2.5-fold increase in their Young moduli, e.g., from 38 ± 1 to 99 ± 4 kPa at a HA:HNTs weight ratio of 1:2. Although HA:HNTs based cryogels were found to be blood compatible with 1.37 ± 0.11% hemolysis ratio at a HA:HNTs weight ratio of 1:2, they trigger thrombogenic activity with a blood clotting index of 17.3 ± 4.8. Remarkably, HA:HNTs cryogel composites were found to be excellent scaffold materials in the proliferation of rat mesenchymal stem cells (MSC), human cervical carcinoma cells (HeLa), and human colon cancer cells (HCT116). The cell studies revealed that an increased amount of HNT embedding into HA cryogels leads to an increase of MSC proliferation.

Topics: Animals; Biocompatible Materials; Cells, Cultured; Clay; Cryogels; Hemolysis; Humans; Hyaluronic Acid; Materials Testing; Nanotubes; Spectrum Analysis; Thermogravimetry; Tissue Engineering; Tissue Scaffolds

The objective of this study is to design biomimetic organically modified montmorillonite clay (OMMT) supported chitosan/hydroxyapatite-zinc oxide (CTS/HAP-ZnO) nanocomposites (ZnCMH I-III) with improved mechanical and biological properties compared to previously reported CTS/OMMT/HAP composite. Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to analyze the composition and surface morphology of the prepared nanocomposites. Strong antibacterial properties against both Gram-positive and Gram-negative bacterial strains were established for ZnCMH I-III. pH and blood compatibility study revealed that ZnCMH I-III should be nontoxic to the human body. Cytocompatibility of these nanocomposites with human osteoblastic MG-63 cells was also established. Experimental findings suggest that addition of 5wt% of OMMT into CTS/HAP-ZnO (ZnCMH I) gives the best mechanical strength and water absorption capacity. Addition of 0.1wt% of ZnO nanoparticles into CTS-OMMT-HAP significantly enhanced the tensile strengths of ZnCMH I-III compared to previously reported CTS-OMMT-HAP composite. In absence of OMMT, control sample (ZnCH) also showed reduced tensile strength, antibacterial effect and cytocompatibility with osteoblastic cell compared to ZnCMH I. Considering all of the above-mentioned studies, it can be proposed that ZnCMH I nanocomposite has a great potential to be applied in bone tissue engineering.

Topics: Aluminum Silicates; Bacillaceae; Bacillus cereus; Biocompatible Materials; Bone and Bones; Cell Line, Tumor; Cell Survival; Chitosan; Clay; Durapatite; Erythrocytes; Escherichia coli; Hemolysis; Humans; Materials Testing; Microbial Viability; Nanocomposites; Osteoblasts; Tensile Strength; Tissue Engineering; Tissue Scaffolds; Zinc Oxide

Many researchers have investigated the application of halloysite nanotubes (HNTs) in biomedicine, because of their special nanoscale hollow tubular structure. Although the cytocompatibility of HNTs has been studied, their blood compatibility has not been systematically investigated. In this work, the effect of HNTs on the structure and function of different blood components has been studied, including the morphology and hemolysis of red blood cells (RBCs). Based on scanning electron microscopy (SEM) observations, optical density test and flow cytometry analysis, we found that HNTs can affect the morphology and membrane integrity of RBCs in phosphate buffered saline (PBS) in a content-dependent way. In particular, based on UV-vis absorption spectra, fluorescence spectra and circular dichroism (CD) spectra, HNTs can alter the secondary structure and conformation of human fibrinogen and γ-globulins. In addition, the detection of biomarker molecules C3a and C5a in plasma suggests that HNTs can trigger complement activation. In the blood clotting assay, HNTs were found to significantly prolong the activated partial thromboplastin time (APTT), shorten the prothrombin time (PT) of platelet-poor plasma (PPP), and change the thromboelastography (TEG) parameters of whole blood coagulation. Furthermore, confocal laser scanning microscopy and flow cytometry analysis were used to test intracellular uptake by macrophages, and the cellular uptake of HNTs in the RAW 264.7 was found to be content-dependent, but not time-dependent. These findings provide insight for the potential use of HNTs as biofriendly nanocontainers for biomaterials in vivo.

Topics: Aluminum Silicates; Animals; Blood Coagulation; Cattle; Clay; Erythrocyte Membrane; Fibrinogen; gamma-Globins; Hemolysis; Humans; Mice; Nanotubes; RAW 264.7 Cells; Structure-Activity Relationship

Modification of the quartz surface by aluminium salts and metallic iron have been shown to reduce the biological activity of quartz. This study aimed to investigate the ability of water soluble extracts of coal mine dust (CMD), low aluminium clays (hectorite and montmorillonite) and high aluminium clays (attapulgite and kaolin) to inhibit the reactivity of the quartz surface. DQ12 induced significant haemolysis of sheep erythrocytes in vitro and inflammation in vivo as indicated by increases in the total cell numbers, neutrophil cell numbers, MIP-2 protein and albumin content of bronchoalveolar lavage (BAL) fluid. Treatment of DQ12 with CMD extract prevented both haemolysis and inflammation. Extracts of the high aluminium clays (kaolin and attapulgite) prevented inhibition of DQ12 induced haemolysis, and the kaolin extract inhibited quartz driven inflammation. DQ12 induced haemolysis by coal mine dust and kaolin extract could be prevented by pre-treatment of the extracts with a cation chellator. Extracts of the low aluminium clays (montmorillonite and hectorite) did not prevent DQ12 induced haemolysis, although the hectorite extract did prevent inflammation. These results suggest that CMD, and clays both low and rich in aluminium, all contain soluble components (possibly cations) capable of masking the reactivity of the quartz surface.

Topics: Administration, Inhalation; Aluminum Silicates; Animals; Bronchoalveolar Lavage Fluid; Clay; Coal; Dust; Erythrocytes; Hemolysis; In Vitro Techniques; Kaolin; Magnesium Compounds; Quartz; Rats; Sheep; Silicon Compounds; Solubility; Surface Properties

We studied one sample of commercial sepiolite and two samples of commercial vermiculite--clay minerals proposed as replacements for asbestos--and tested in vitro their abilities to activate complement, to lyse erythrocytes, and to elicit the production of reactive oxygen species (ROS) with human polymorphonuclear leukocytes (PMN) or bovine alveolar macrophages (AM); their behavior was compared with that of asbestos fibers obtained from the Union International Contra Cancer (UICC) as reference standards, as well as with kaolinite and illite, main members of the clay mineral family. Since in short-term in vitro tests the biological activity of mineral particles seems especially related to the active sites on their surface, we first measured the specific surface area of each mineral. Sepiolite was unreactive in two of the three tests we used (complement activation and ROS production) and able to lyse a minimal percentage of red blood cells. Vermiculite was shown to be incapable of activating complement, to have a moderate hemolytic activity and a high ability to elicite ROS production, although lower than that of chrysotile. Sepiolite, therefore, might be of more interest than vermiculite, given the low level of biological effects detected during the tests used to compare both clay minerals with asbestos fibres. The ROS production does not seem to require phagocytosis. A high ROS production was observed with kaolinite: this result casts doubt on the ability of pathogenic mineral dusts in vitro to induce a greater release of ROS than nonpathogenic mineral dusts.

Topics: Acridines; Aluminum Silicates; Animals; Antacids; Antidiarrheals; Asbestos; Asbestos, Crocidolite; Asbestos, Serpentine; Carcinogens; Cattle; Clay; Complement Activation; Dose-Response Relationship, Drug; Erythrocytes; Hemolysis; Humans; Kaolin; Linear Models; Luminescent Measurements; Luminol; Macrophages, Alveolar; Magnesium Silicates; Minerals; Neutrophils; Reactive Oxygen Species; Tetradecanoylphorbol Acetate; Zymosan