Miscibility of sodium chloride and sodium dodecyl sulfate in the adsorbed film and aggregate

The adsorption, micelle formation, and salting out of sodium dodecyl sulfate in the presence of sodium chloride were studied from the viewpoint of their mixed adsorption and aggregate formation. The surface tension of aqueous solutions of a sodium chloride–sodium dodecyl sulfate mixture was measured as a function of the total molality and composition of the mixture. Phase diagrams of adsorption and aggregate formation were obtained by applying thermodynamic equations to the surface tension. Judging from the phase diagrams, sodium chloride and sodium dodecyl sulfate are miscible in the adsorbed film at very large composition of sodium chloride and in the salted-out crystalline particle, while they are immiscible in the micelle. The miscibilities in the adsorbed film, micelle, and crystalline particle increase in the following order: particle > adsorbed film > micelle. The difference in miscibility among the oriented states was ascribed to the difference in geometry between the adsorbed film and micelle and to the interaction between bilayer surfaces in the particle

Exponentially fast Thinning of Nanoscale Films by Turbulent Mixing

Films are nanoscopic elements of foams, emulsions and suspensions, and form a paradigm for nanochannel transport that eventually tests the limits of hydrodynamic descriptions. Here, we study the collapse of a freestanding film to its equilibrium. The generation of nanoscale films usually is a slow linear process; using thermal forcing we find unprecedented dynamics with exponentially fast thinning. The complex interplay of thermal convection, interface and gravitational forces yields optimal turbulent mixing and transport. Domains of collapsed film are generated, elongated and convected in a beautiful display of chaotic mixing. With a timescale analysis we identify mixing as the dominant dynamical process responsible for exponential thinning.Comment: accepted for publication in Phys. Rev. Let

Comparison of material-mediated bone regeneration capacities of sintered and non-sintered xenogeneic bone substitutes via 2D and 3D data

Background/Aim: The aim of this study was the development of a new osteoconductivity index to determine the bone healing capacities of bone substitute materials (BSM) on the basis of 3D microcomputed tomographic (μ-CT) data. Materials and Methods: Sinus biopsies were used for the comparative analysis of the integration behavior of two xenogeneic BSM (cerabone® and Bio Oss®). 3D μ-CT and data sets from histomorphometrical measurements based on 2D histological slices were used to measure the bone-material-contact and the tissue distribution within the biopsies. The tissue reactions to both BSM were microscopically analyzed. Results: The 3D and 2D results of the osteoconductivity measurements showed comparable material-bone contacts for both BSM, but the 2D data were significantly lower. The same results were found when tissue distribution was measured in both groups. The histopathological analysis showed comparative tissue reactions in both BSM. Conclusion: Osteoconductivity index is a reliable measurement parameter for determining the healing capacities of BSM. The observed differences between both measurement methods could be assigned to the resolution capacity of μ-CT data that did not allow for a precise interface distinction between both BSM and bone tissue. Histomorphometrical data based on histological slides still allow for a more exact evaluation

Editorial: Functional surfaces and biomaterials

At the beginning of 2022, Frontiers in Bioengineering and Biotechnology - Biomaterials Section has published a Research Topic on “Functional Surfaces and Biomaterials.” The aim of this Research Topic is to summarize the current state of research and development in the field of functional surfaces and biomaterials with a particular focus on biotechnological and medical applications. The guest editorial team would like to thank all colleagues from around the world who submitted their reviews and research articles for the Research Topic. By the end of August 2022, we have successfully collected 20 articles by 138 participating authors following the peer review process. We also tried to select manuscripts from different research areas to cover the most relevant Research Topic of interest, from drug delivery systems to bone tissue engineering to biosensors and general aspects in biomedicine. By the end of December, the 20 articles had been viewed for more than 21000 times with downloads more than 4,000 times, and 11 articles have reached more than 1,000 views

The Granule Size Mediates the In Vivo Foreign Body Response and the Integration Behavior of Bone Substitutes

The physicochemical properties of synthetically produced bone substitute materials (BSM) have a major impact on biocompatibility. This affects bony tissue integration, osteoconduction, as well as the degradation pattern and the correlated inflammatory tissue responses including macrophages and multinucleated giant cells (MNGCs). Thus, influencing factors such as size, special surface morphologies, porosity, and interconnectivity have been the subject of extensive research. In the present publication, the influence of the granule size of three identically manufactured bone substitute granules based on the technology of hydroxyapatite (HA)-forming calcium phosphate cements were investigated, which includes the inflammatory response in the surrounding tissue and especially the induction of MNGCs (as a parameter of the material degradation). For the in vivo study, granules of three different size ranges (small = 0.355–0.5 mm; medium = 0.5–1 mm; big = 1–2 mm) were implanted in the subcutaneous connective tissue of 45 male BALB/c mice. At 10, 30, and 60 days post implantationem, the materials were explanted and histologically processed. The defect areas were initially examined histopathologically. Furthermore, pro- and anti-inflammatory macrophages were quantified histomorphometrically after their immunohistochemical detection. The number of MNGCs was quantified as well using a histomorphometrical approach. The results showed a granule size-dependent integration behavior. The surrounding granulation tissue has passivated in the groups of the two bigger granules at 60 days post implantationem including a fibrotic encapsulation, while a granulation tissue was still present in the group of the small granules indicating an ongoing cell-based degradation process. The histomorphometrical analysis showed that the number of proinflammatory macrophages was significantly increased in the small granules at 60 days post implantationem. Similarly, a significant increase of MNGCs was detected in this group at 30 and 60 days post implantationem. Based on these data, it can be concluded that the integration and/or degradation behavior of synthetic bone substitutes can be influenced by granule size.DFG, 414044773, Open Access Publizieren 2021 - 2022 / Technische Universität Berli