THE INTERACTION OF HUMAN OSTEOBLAST-LIKE Saos-2 CELLS WITH STAINLESS STEEL AND Si(100) COATED BY SILICALITE 1 FILMS

Interaction of osteoblast-like Saos-2 cells with stainless steel and Si(100) covered by a film of densely intergrown silicalite-1 crystals is investigated.  Surface properties  of the films are tuned by synthesis conditions and post-synthetic modifications.  A number of adhered cells is affected by surface morphology and wettability of the film

Constitutive activity of the M1–M4 subtypes of muscarinic receptors in transfected CHO cells and of muscarinic receptors in the heart cells revealed by negative antagonists

AbstractWe investigated whether muscarinic receptors of the M1–M4 receptor subtypes are constitutively active. We have found that the synthesis of cyclic AMP was enhanced by the muscarinic antagonists atropine and N-methylscopolamine (NMS) in Chinese hamster ovary (CHO) cells stably transfected with human m2 and m4 muscarinic receptor genes and in rat cardiomyocytes expressing the M2 receptor subtype, and that the production of inositol phosphates was inhibited by atropine and NMS in CHO cells stably transfected with human m1 and m3 and with rat m1 muscarinic receptor genes. The muscarinic antagonists quinuclidinyl benzilate and AF-DX 116 had no effect in some cases and acted like atropine and NMS in others. We conclude that the M1–M4 subtypes of muscarinic receptors are constitutively active in the CHO cell lines expressing them and in cardiomyocytes and that atropine and NMS act as negative antagonists on these receptor subtypes by stabilizing them in the inactive conformation

THE INTERACTION OF HUMAN OSTEOBLAST-LIKE SAOS-2 CELLS WITH STAINLESS STEEL AND SI(100) COATED BY SILICALITE 1 FILMS

Interaction of osteoblast-like Saos-2 cells with stainless steel and Si(100) covered by a film of densely intergrown silicalite-1 crystals is investigated.  Surface properties  of the films are tuned by synthesis conditions and post-synthetic modifications.  A number of adhered cells is affected by surface morphology and wettability of the film.</p

Cell type specific adhesion to surfaces functionalised by amine plasma polymers

Our previously-obtained impressive results of highly increased C2C12 mouse myoblast adhesion to amine plasma polymers (PPs) motivated current detailed studies of cell resistance to trypsinization, cell proliferation, motility, and the rate of attachment carried out for fibroblasts (LF), keratinocytes (HaCaT), rat vascular smooth muscle cells (VSMC), and endothelial cells (HUVEC, HSVEC, and CPAE) on three different amine PPs. We demonstrated the striking difference in the resistance to trypsin treatment between endothelial and non-endothelial cells. The increased resistance observed for the non-endothelial cell types was accompanied by an increased rate of cellular attachment, even though spontaneous migration was comparable to the control, i.e., to the standard cultivation surface. As demonstrated on LF fibroblasts, the resistance to trypsin was similar in serum-supplemented and serum-free media, i.e., medium without cell adhesion-mediating proteins. The increased cell adhesion was also confirmed for LF cells by an independent technique, single-cell force spectroscopy. This method, as well as the cell attachment rate, proved the difference among the plasma polymers with different amounts of amine groups, but other investigated techniques could not reveal the differences in the cell behaviour on different amine PPs. Based on all the results, the increased resistance to trypsinization of C2C12, LF, HaCaT, and VSMC cells on amine PPs can be explained most probably by a non-specific cell adhesion such as electrostatic interaction between the cells and amine groups on the material surface, rather than by the receptor-mediated adhesion through serum-derived proteins adsorbed on the PPs

Application of whey protein isolate in bone regeneration:Effects on growth and osteogenic differentiation of bone-forming cells

Recently, milk-derived proteins have attracted attention for applications in the biomedical field such as tissue regeneration. Whey protein isolate (WPI), especially its main component β-lactoglobulin, can modulate immunity and acts as an antioxidant, antitumor, antiviral, and antibacterial agent. There are very few reports of the application of WPI in tissue engineering, especially in bone tissue engineering. In this study, we tested the influence of different concentrations of WPI on behavior of human osteoblast-like Saos-2 cells, human adipose tissue-derived stem cells (ASC), and human neonatal dermal fibroblasts (FIB). The positive effect on growth was apparent for Saos-2 cells and FIB but not for ASC. However, the expression of markers characteristic for early osteogenic cell differentiation [type-I collagen (COL1) and alkaline phosphatase (ALP)] as well as ALP activity, increased dose-dependently in ASC. Importantly, Saos-2 cells were able to deposit calcium in the presence of WPI, even in a proliferation medium without other supplements that support osteogenic cell differentiation. The results indicate that, depending on the cell type, WPI can act as an enhancer of cell proliferation and osteogenic differentiation. Therefore, enrichment of biomaterials for bone regeneration with WPI seems a promising approach, especially due to the low cost of WPI

Phytase-mediated enzymatic mineralization of chitosan-enriched hydrogels

Hydrogels mineralized with calcium phosphate (CaP) are increasingly popular bone regeneration biomaterials. Mineralization can be achieved by phosphatase enzyme incorporation and incubation in calcium glycerophosphate (CaGP). Gellan gum (GG) hydrogels containing the enzyme phytase and chitosan oligomer were mineralized in CaGP solution and characterized with human osteoblast-like MG63 cells and adipose tissue-derived stem cells (ADSC). Phytase induced CaP formation. Chitosan concentration determined mineralization extent and hydrogel mechanical reinforcement. Phytase-induced mineralization promoted MG63 adhesion and proliferation, especially in the presence of chitosan, and was non-toxic to MG63 cells (with and without chitosan). ADSC adhesion and proliferation were poor without mineralization. Chitosan did not affect ADSC osteogenic differentiation

Hybrid coatings for orthopaedic implants formed by physical vapour deposition and microarc oxidation

This study is focused on the preparation of new hybrid layers intended for surface modification of Ti-6Al-4V alloys for potential orthopaedic and dental applications. Combination of the technology of physical vapour deposition (PVD) and subsequent micro-arc oxidation (MAO) was utilized for the deposition of Ti and ZrTi to form hybrid oxide layers. The oxide layers were prepared using an alkaline electrolyte with glycerol as an additive under micro-arc discharge conditions with different Si content on their surfaces. The hybrid ZrTi coatings with a Zr/Si structure achieved the best tribological properties described by a low friction coefficient of 0.3 and high abrasion resistance. There was also an increase in corrosion potential and polarization resistance of hybrid ZrTi coatings. Although the proliferation of human bone marrow mesenchymal stem cells was slower on these hydrophilic Ti and ZrTi coatings than both on uncoated Ti-6Al-4V and the reference tissue culture polystyrene dishes, both types of hybrid coating promoted greater osteogenic differentiation of these cells, indicated by approx. twice as high activity of alkaline phosphatase. The hybrid oxide layers newly developed in this study - especially the layers with Zr - are therefore promising for coating metallic bone implants.Web of Science219art. no. 11081

Novel multicomponent organic-inorganic WPI/gelatin/CaP hydrogel composites for bone tissue engineering

The present work focuses on the development of novel multicomponent organic‐inorganic hydrogel composites for bone tissue engineering. For the first time, combination of the organic components commonly used in food industry, namely whey protein isolate (WPI) and gelatin from bovine skin, as well as inorganic material commonly used as a major component of hydraulic bone cements, namely α‐TCP in various concentrations (0‐70 wt.%) was proposed. The results showed that α‐TCP underwent incomplete transformation to calcium‐deficient hydroxyapatite (CDHA) during preparation process of the hydrogels. Microcomputer tomography showed inhomogeneous distribution of the calcium phosphate (CaP) phase in the resulting composites. Nevertheless, hydrogels containing 30‐70 wt.% α‐TCP showed significantly improved mechanical properties. The values of Young's modulus and the stresses corresponding to compression of a sample by 50% increased almost linearly with increasing concentration of ceramic phase. Incomplete transformation of α‐TCP to CDHA during preparation process of composites provides them high reactivity in simulated body fluid during 14‐day incubation. Preliminary in vitro studies revealed that the WPI/gelatin/CaP composite hydrogels support the adhesion, spreading, and proliferation of human osteoblast‐like MG‐63 cells. The WPI/gelatin/CaP composite hydrogels obtained in this work showed great potential for the use in bone tissue engineering and regenerative medicine applications