Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis.

Surface modification of polyurethane with eptifibatide-loaded degradable nanoparticles reducing risk of blood coagulation.

The main purpose of the work was to develop a drug releasing coatings on the surface of medical devices exposed to blood flow, what should enable effective inhibition of blood coagulation process. As a part of the work, the process of encapsulating the anticoagulant drug eptifibatide (EPT) in poly(DL-lactic-co-glycolic acid) (PLGA) nanoparticles was developed. EPT encapsulation efficiency was 29.

Surface-Modified Poly(l-lactide--glycolide) Scaffolds for the Treatment of Osteochondral Critical Size Defects-In Vivo Studies on Rabbits.

Poly(l-lactide--glycolide) (PLGA) porous scaffolds were modified with collagen type I (PLGA/coll) or hydroxyapatite (PLGA/HAp) and implanted in rabbits osteochondral defects to check their biocompatibility and bone tissue regeneration potential. The scaffolds were fabricated using solvent casting/particulate leaching method. Their total porosity was 85% and the pore size was in the range of 250-320 µm.

Evaluation of the In Vitro Stability of Stimuli-Sensitive Fatty Acid-Based Microparticles for the Treatment of Lung Cancer.

The fatty acid-based microparticles containing iron oxide nanoparticles and paclitaxel (PAX) are a viable proposition for the treatment of lung cancer. The microparticles inhaled as a dry powder can be guided to selected locations using an external magnetic field, and when accumulated there, the active compound release can be triggered by local hyperthermia. However, this general strategy requires that the active compound is released from microparticles and can reach the targeted cells before microparticles are removed.

Sodium alendronate loaded poly(l-lactide- -glycolide) microparticles immobilized on ceramic scaffolds for local treatment of bone defects.

Bone tissue regeneration in critical-size defects is possible after implantation of a 3D scaffold and can be additionally enhanced once the scaffold is enriched with drugs or other factors supporting bone remodelling and healing. Sodium alendronate (Aln), a widely used anti-osteoporosis drug, exhibits strong inhibitory effect on bone resorption performed by osteoclasts. Thus, we propose a new approach for the treatment of bone defects in craniofacial region combining biocompatible titanium dioxide scaffolds and poly(l-lactide--glycolide) microparticles (MPs) loaded with Aln.

Superparamagnetic Iron Oxide Nanoparticles Modified with Silica Layers as Potential Agents for Lung Cancer Treatment.

Superparamagnetic iron oxide nanoparticles (SPIONs) are promising drug delivery carriers and hyperthermia agents for the treatment of cancer. However, to ensure their safety in vivo, SPIONs must be modified in order to prevent unwanted iron release. Thus, SPIONs were coated with silica layers of different morphologies: non-porous (@SiO), mesoporous (@mSiO) or with a combination of non-porous and mesoporous layers (@SiO@mSiO) deposited via a sol-gel method.

Stimuli-sensitive fatty acid-based microparticles for the treatment of lung cancer.

Despite recent advancements in medicine, lung cancer still lacks an effective therapy. In the present study we have decided to combine superparamagnetic iron oxide nanoparticles (SPION) with solid lipid microparticles to develop novel, stimuli-sensitive drug carriers that increase the bioavailability of the anticancer drug (paclitaxel - PAX) through guided accumulation directly at the tumour site and controlled drug delivery. SPION and PAX-loaded microparticles (MPs) were fabricated from lauric acid (LAU) and a mixture of myristic and palmitic acids (MYR/PAL) using hot oil-in-water emulsification method.

Physico-Chemical Characterization and Biological Tests of Collagen/Silk Fibroin/Chitosan Scaffolds Cross-Linked by Dialdehyde Starch.

In this study, three-dimensional (3D) biopolymeric scaffolds made from collagen, silk fibroin and chitosan were successfully prepared by the freeze drying method. Dialdehyde starch (DAS) was used as a cross-linking agent for the materials. The properties of the materials were studied using density and porosity measurements, scanning electron microscope (SEM) imaging, swelling and moisture content measurements.

Distinct Influence of Saturated Fatty Acids on Malignant and Nonmalignant Human Lung Epithelial Cells.

The impact of saturated fatty acids (FA) on viability and properties of malignant and nonmalignant cells has not been studied in detail so far. The present study was aimed at evaluation of the influence of saturated FA (10:0-18:0) on malignant (A459) and nonmalignant (BEAS-2B) human lung epithelial cells. FA strongly affected A549 cells, but not BEAS-2B cells.

Mineralization of gellan gum hydrogels with calcium and magnesium carbonates by alternate soaking in solutions of calcium/magnesium and carbonate ion solutions.

Mineralization of hydrogels is desirable prior to applications in bone regeneration. CaCO is a widely used bone regeneration material, and Mg, when used as a component of calcium phosphate biomaterials, has promoted bone-forming cell adhesion and proliferation and bone regeneration. In this study, gellan gum hydrogels were mineralized with carbonates containing different amounts of calcium (Ca) and magnesium (Mg) by alternate soaking in, firstly, a calcium and/or magnesium ion solution and, secondly, a carbonate ion solution.

Animal models of smoke inhalation injury and related acute and chronic lung diseases.

Smoke inhalation injury leads to various acute and chronic lung diseases and thus is the dominant cause of fire-related fatalities. In a search for an effective treatment and validation of therapies different classes of animal models have been developed, which include both small and large animals. These models have advanced our understanding of the mechanism of smoke inhalation injury, enabling a better understanding of pathogenesis and pathophysiology and development of new therapies.

Ca:Mg:Zn:CO and Ca:Mg:CO-tri- and bi-elemental carbonate microparticles for novel injectable self-gelling hydrogel-microparticle composites for tissue regeneration.

Injectable composites for tissue regeneration can be developed by dispersion of inorganic microparticles and cells in a hydrogel phase. In this study, multifunctional carbonate microparticles containing different amounts of calcium, magnesium and zinc were mixed with solutions of gellan gum (GG), an anionic polysaccharide, to form injectable hydrogel-microparticle composites, containing Zn, Ca and Mg. Zn and Ca were incorporated into microparticle preparations to a greater extent than Mg.

Novel injectable, self-gelling hydrogel-microparticle composites for bone regeneration consisting of gellan gum and calcium and magnesium carbonate microparticles.

The suitability of hydrogel biomaterials for bone regeneration can be improved by incorporation of an inorganic phase in particle form, thus maintaining hydrogel injectability. In this study, carbonate microparticles containing different amounts of calcium (Ca) and magnesium (Mg) were added to solutions of the anionic polysaccharide gellan gum (GG) to crosslink GG by release of Ca and Mg from microparticles and thereby induce formation of hydrogel-microparticle composites. It was hypothesized that increasing Mg content of microparticles would promote GG hydrogel formation.

Enrichment of enzymatically mineralized gellan gum hydrogels with phlorotannin-rich Ecklonia cava extract Seanol(®) to endow antibacterial properties and promote mineralization.

Hydrogels offer several advantages as biomaterials for bone regeneration, including ease of incorporation of soluble substances such as mineralization-promoting enzymes and antibacterial agents. Mineralization with calcium phosphate (CaP) increases bioactivity, while antibacterial activity reduces the risk of infection. Here, gellan gum (GG) hydrogels were enriched with alkaline phosphatase (ALP) and/or Seanol(®), a seaweed extract rich in phlorotannins (brown algae-derived polyphenols), to induce mineralization with CaP and increase antibacterial activity, respectively.

The influence of sintering conditions on microstructure and mechanical properties of titanium dioxide scaffolds for the treatment of bone tissue defects.

In this study the attempts to improve mechanical properties of highly-porous titanium dioxide scaffolds produced by polymer sponge replication method were investigated. Particularly the effect of two-step sintering at different temperatures on microstructure and mechanical properties (compression test) of the scaffolds were analysed. To this end microcomputed tomography and scanning electron microscopy were used as analytical methods.

Methodology and evaluation of the renal arterial system.

Introduction: The broad range of medical images and image processing technologies are applied in urology. The aim was to propose methodology to assess three-dimensional (3D) arrangement of renal arterial tree and to build a statistical model for analyzing the layout of arteries in the sections of the kidney.

Methods: The series of kidney CT slices are analyzed using image processing procedures and further the 3D model of arterial systems is converted to a graph tree which includes information about features of the renal arterial system.