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Natural biodegradable and biocompatible polysaccharides chitosan, pectin, carrageenan and heparin were used to form thin nanostructured films. In this study using atomic force microscopy (AFM) and force spectroscopy the special characteristics of formation and structure of thin coatings were investigated, three models of the polymers interaction were proposed. Different mechanisms of polymers influence on each other in the bilayers formation were shown, coatings with different surface structure and mechanical properties were formed. The obtained data can be used for the preparation of nanostructured coatings with desired surface parameters.

Today, there is a need for the development of biomaterials with novel properties for biomedical purposes. The biocompatibility of materials is a key factor in determining its possible use in biomedicine. In this study, composite cryogels were obtained based on pectin and chitosan using ionic cryotropic gelation. For cryogel preparation, apple pectin (AP), Heracleum L. pectin (HP), and chitosan samples with different physical and chemical characteristics were used. The properties of pectin-chitosan cryogels were found to depend on the structural features and physicochemical characteristics of the pectin and chitosan within them. The addition of chitosan to cryogels can increase their mechanical strength, cause change in surface morphology, increase the degradation time, and enhance adhesion to biological tissues. Cryogels based on AP were less immunogenic when compared with cryogels from HP. Cryogels based on AP and HP were hemocompatible and the percentage of red blood cells hemolysis was less than 5%. Unlike cryogels based on HP, which exhibited moderate cytotoxicity, cryogels based on AP exhibited light cytotoxicity. Based on the results of low immunogenicity, light cytotoxicity data as well as a low level of hemolysis of composite cryogels based on AP and chitosan are biocompatible and can potentially be used in biomedicine. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 547-556, 2017.

Chitosan is a biodegradable and biocompatible polysaccharide widely used in different applications in medicine. The polycationic structure of the polymer provides many possibilities for its modification. One of the most interesting applications of chitosan is the development of nanosized delivery systems for biologically active molecules. The functional properties of these delivery systems depend severely on the structure and properties of nanoparticles. Using dynamic light scattering, atomic force microscopy, and to confocal microscopy, we have shown that both hexanoyl chitosan (HC) and succinoyl chitosan (SC) formed nanoparticles of comparable diameters from 120 to 250 nm. Using several methods of analysis helped us identify a minor fraction with a larger size of 600 to 700 nm formed by nanoparticle aggregates. The determined ζ potential was from −20 to −25 mV for SC nanoparticles and from 30 to 35 mV for HC nanoparticles.

The conditions of succinylchitosan-based nanostructures with doxorubicin preparation were optimized. Nanoparticles were obtained using a precipitation conservation method for the first time, and the particles were further used to prepare noncovalent complexes with doxorubicin. The physicochemical and biological properties of the studied structures were investigated. It was shown that the average size of the obtained nanostructures is 200–250 nm and their ζ-potential was determined as negative (−20 to −25 mV). Nanoparticles loaded with doxorubicin were shown to demonstrate a positive cytotoxic effect in vitro. Doxorubicin sorbtion on nanoparticles resulted in no changes in the properties of the drug, which may make it possible to lower its toxicity in vivo.

The hierarchically structured glass sponge Caulophacus species uses the first known example of a silica and calcite biocomposite to join the spicules of its skeleton together. In the stalk and body skeleton of this poorly known deep-sea glass sponge siliceous spicules are modified by the addition of conical calcite seeds, which then form the basis for further silica secretion to form a spinose region. Spinose regions on adjacent spicules are then joined by siliceous crosslinks, leading to unusually strong cross-spicule linkages. In addition to the biomaterials implications it is now clear, from this first record of a biomineral other than silica, that the hexactinellid sponges are capable of synthesizing calcite, the ancestral skeletal material. We propose that, while the low concentrations of calcium in deep sea waters drove the evolution of silica skeletons, the brittleness of silica has led to retention of the more resilient calcite in very low concentrations at the skeletal joints.

6 páginas, 4 figuras., The complex process of supercontinuum generation (SG) is known to be exploitable for designing spatially coherent white light sources emitting light simultaneously in the ultraviolet, visible, and infrared ranges. Herein the first natural material able to generate in laboratory conditions a supercontinuum similar to those known from man-made photonic crystal fibers is described. The ability resides in siliceous 20–50 cm long spicules of the glass sponge Sericolophus hawaiicus. By shedding into the spicules optical peak intensities ranging from 1 to 100 TW cm−2 the generation of a SG is revealed. The SG involves wavelengths between 650 and 900 nm and shows a maximum spectral spread for excitation at a wavelength of 750 nm. It is hypothesized that the SG is favored by spicules being a biocomposite that incorporates together isotopically pure biogenic silica (δ30Si = −3.28) and 15.2 ± 1.3 μg N-acetyl-glucosamine (chitin) per mg of silica. The internal organization of these spicules is distinguished by a solid silica core with a 1 μm wide axial channel as well as a highly ordered silica–chitin composite. Such a composition and organization pattern may be of potential interest for the design of low temperature synthesis of future materials for light guidance., This work was partially supported by the following research grants DFG Grant EH 394/3-1, Krüger Research School, Biohydrometallurgical Center for Strategic Elements (BHMZ) at TU Bergakademie Freiberg, BMBF within the project CryPhys Concept (03EK3029A), Germany, and a grant of the Spanish Government (CTM2015-67221-R) to M.M.