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The halloysite/3-Aminopropyltrietthoxysilane/gentamicin hybrid was obtained as a novel carrier for sustained drug release in antimicrobial treatment. The nanocarrier was prepared by functionalizing the halloysite surface with the 3-Aminopropyltrietthoxysilane, which was introduced into the system as a coupling agent to efficiently bond the drug in to the halloysite lumen. The interaction between gentamicin, silane and halloysite as well as the antimicrobial susceptibility against E. coli, S. aureus and S. epidermidis were investigated. The results indicate that silane grafting combined with intercalation of gentamicin resulted in efficient drug bonding to the inner surface of halloysite and ultimately extended drug release from the tested hybrid.

The paper focuses on the results of research on the development of newly designed white glazes without the addition of traditional opacifiers such as ZrO2 or ZrSiO4, intended for use in ceramic sanitary products. The effect of opacity was obtained by introducing ZnO in quantities of 4–8 wt% to the sets of glazes. ZnO introduced to the glaze compositions resulted in crystallization of gahnite, and gahnite caused the glaze to become opaque and white. Measurements of the whiteness of glazes confirmed its high level, over 90 units were noticed according to the CIE Lab scale. The microstructure and structure of the glazes were measured by scanning electron microscopy and X-ray diffractometry. The colour and gloss of the glazes were measured using a spectrophotometer and a gloss meter. The topography of the glaze surfaces, as well as the roughness level (Ra), were measured using a confocal microscope.

In this study, we propose a new approach in the anterior cruciate ligament (ACL) replacement to provide stability and integration with bone tunnel. A polylactide (PLA)-based tubular implant was used to support the graft stabilization in femoral and tibial bones and to stimulate the healing process after (ACL) replacement on a sheep model. The ACL was replaced with an autologous Achilles tendon split graft. The tendon-to-bone healing in the model was analyzed after 6 and 12 weeks. Two groups of animals were compared, i.e. the group with the PLA-based implant used in the ACL replacement and the control group without the implant. The knee joints were mechanically and clinically evaluated, including the histopathology tests, to determine their stability and integrity. The results indicated that the bioresorbable PLA-based tubular implant may facilitate integration of the tendon graft with bone. Remodeling the allograft inside the implant improves the joint mobility from the first week of healing: no pathological changes were observed at the surgery site and in the animals’ mobility. After 6 and 12 weeks of healing no significant changes in the mechanical parameters of the knee joint were observed, regarding the joint failure force, knee displacement, angular mobility range and joint stiffness. Relatively small values of the non-destructive tests in the knee displacement, already 6 weeks after surgery, indicated the early stabilization of the knee joint. The studies showed that the failure forces of knee joints after the ACL replacement with the PLA-based implant are lower than those of an intact joint, although their biomechanical features, including strain-at- failure, are similar. The biomechanical parameters of the knee joint were significantly improved due to the selected method of attaching the autograft ends to the femoral and tibial bone surfaces. After 12 weeks the intra-tunnel tendon-bone site with the PLA implant revealed the better tibia-femur joint mechanical stability, linear force-strain function and the decreasing strain-to-failure value, as compared to the control group.

The aim of this study was to develop new compositions of white glazes without the addition of ZrSiO 4 designed for sanitary products obtained in a 12-h firing cycles at a maximum temperature of 1230 °C. Alternative glazes with a good opacity and a high degree of whiteness were obtained, composed primarily of raw materials available on the domestic market in Poland. The opaque effect was achieved due to crystallisation of anorthite, which was identified as a major crystalline phase in the system. The glazes were characterised by a high whiteness value L*, greater than 90 in the CIELAB colour space, and a gloss, measured with a 60° light incident angle on the glaze surface, above 50%. The microstructure and structure of the glazes were measured with the use of a Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). The colour and gloss of glazes were measured with the use of a spectrophotometer and a gloss metre at a 60° angle of incidence. The topography of glazes surfaces, as well as the roughness level (Ra), were measured with the use of a confocal microscope.

The effect of the BaO addition on the microstructure and structure of the glasses from the K2O–MgO–CaO–Al2O3–SiO2-(BaO) system was investigated in this study. The results were obtained by testing the crystallization capability of the glasses during the fast-firing cycle. Thermal analysis proved a high tendency to crystallize the tested glasses/frits. X-ray analysis showed the presence of diopside and anorthite as the main crystalline phases in all glazes obtained from the tested glasses. Microscopic observations showed that barium oxide introduced in the range of 0.4–2.1 mol% into the examined system strongly influences the number and size of crystalline phases. The introduction of 2.1 mol% BaO into the composition also resulted in crystallization of celsian. The thermal characteristic of the glasses was carried out using differential scanning calorimetry (DSC) and the crystalline phases were determined by X-ray diffractometry. The glaze microstructure was investigated by scanning (SEM) and transmission electron (TEM)microscopy. Additional information on the structure of frits was derived from mid-infrared (MIR) and Raman spectroscopy.

The extracellular matrix (ECM) can be a convenient scaffold used in tissue engineering, regenerative medicine and pharmacy. The synthetic cell matrix should imitate the natural extracellular matrix in both composition and architecture. The study examined fibrous chitosan modified with fragments of human collagen I (10–15 amino acids) mimicking the internal sphere of native protein. The surface of chitosan fibers was modified by physical and chemical methods to obtain polysaccharide-peptide conjugates, which may be considered analogous to the complex of glycosaminoglycans (GAG) and peptides present in the cell matrix. The surface of fibrous chitosan was enriched with fragments of human collagen I, using physicochemical properties (water absorption during electrospraying) and chemical compatibility (activity of amide and peptide groups) during synthesis. The method of modification had an effect on changing the diameter of the fibers and their topography, as assessed by means of a scanning electron microscopy (SEM). The presence of peptides on the surface of the fibers was confirmed by spectroscopic studies (FTIR-ATR and FT Raman). It has been shown that the chemical modification provided a homogeneous distribution of the peptide on the fiber, without changing its morphology as opposed to the physical modification of the fiber, which is visible on the surface in the form of peptide aggregates. The biocompatibility of the materials thus obtained was confirmed during biological studies using MG-63 osteoblast-like cells. Correct morphology observed after 3 days of culture (live-dead test) confirmed the suitability of the substrates for biomedical applications.

Although the degradation of polylactide has been relatively well understood, there is still a lack of reliable data on the behavior of its composites at specific temperatures. This paper studies the hydrolytic degradability of polylactide/not activated smectite clay nanocomposites in the 6 weeks accelerated degradation at 80 °C which has not been widely documented so far. The composites with 3 wt%, 5 wt% and 10 wt% of smectite filler content obtained by injection molding were investigated and compared to the neat polylactide matrix material. The results of degradation at 80 °C were referred to the hydrolytic degradation at 25 °C and 37 °C. Macroscopic changes in the nanocomposites, their molecular weight and pH of medium was monitored during the degradation time. The influence of clay addition on the crystallization, glass transition and the melting temperature was also studied by differential scanning calorimetry (DSC). The DSC results show that the presence of smectite clay results in a shift of the onset peak for the melting temperatures towards higher values while for the glass transition towards the lower ones. A significant difference in degradation rate between the polylactide matrix and the polylactide/clay nanocomposites was also noted. The shortened degradation time of the nanocomposites increases their potential for use in biomedical applications, but also in disposable thermoplastic products which are increasingly used.

This paper presents the results of the phase composition study of model systems containing all the main components of the mixtures, used in the laboratory tests of concretes, namely, Al 2 O 3 , CaO and P 2 O 5 . Samples were analysed using X-ray analysis and scanning electron microscopy with EDS analysis in microregions. Four mixtures were tested: one corundum-rich with a small amount of aluminium phosphate and calcium oxide, and three with a high content of aluminium phosphate with the addition of calcium oxide and calcium aluminate. Mixtures to which phosphoric acid was added instead of aluminium phosphate were also studied. It was found that in the model mixtures corresponding to the composition of corundum refractory concretes with small amount of phosphates, two phases are formed, during operation at a temperature of 1400 °C, namely Ca 3 (PO 4 ) 2 and Ca(Al 12 O 19 ). The addition of phosphoric acid resulted in the concrete having the same phase composition as it would had aluminium phosphate and alumina cement been added instead.

The effect of the addition of polypropylene fibres to the corundum concretes containing both high-aluminate cement and aluminium phosphate on the compactness, gas-permeability and pore distribution has been investigated. The mercury porosimetry test results revealed that concretes with the addition of polypropylene fibres, as compared with concretes containing no fibres, exhibit microstructure with an increased quantity of pores of a diameter of about 17 μm, which corresponds in approximation to the fibre diameter and is comparable to AlPO4-containing concretes and to concretes containing aluminate cement only. Specimens of the AlPO4-containing concrete with no fibre addition have lower gas-permeability at temperatures of 110 and 300 °C, as compared to specimens of concrete with aluminate cement only. For both concretes with the polypropylene fibre addition, a similar gas-permeability and its increase with the increase in heating temperature were reported. This is caused most probably by burning out of the fibres creating a micro-channels system in the concrete, which facilitates the gas flow. For these concretes, an increase in the volume of pores is also observed after heating at a temperature of both 110 °C, and 1500 °C.

The Pechinni method (A) as well as hydrothermal treatment (B) of co-precipitated CeO2-based gels with NaOH solution were used to synthesise pure CeO2, and CeO2-based solid solutions with formula Ce1−xMxO2, Ce1−x(M0.5Ca0.5)xO2 M = Gd, Sm for 0.15

Hydroxyapatite is a well-known and valuable implant material with bioactive properties. Full utilisation of the unique properties of hydroxyapatite ceramics is, however, possible only after its proper reinforcement, i.e., by preparation of composites. In the present work zirconia reinforced hydroxyapatite composites were obtained by hot pressing method. The reinforcing phase in the form of ZrO 2 particles was selected due to the satisfactory biocompatibility of ZrO 2 and also because of its exceptional mechanical properties. Our investigations were aimed at assessing the influence of varying ZrO 2 on the phase composition and mechanical properties of HAp–ZrO 2 composites. In order to produce dense sinters, we used three types of initial zirconia powders which differed in morphology and contents of the tetragonal and monoclinic phases. We studied the influence of these oxides on thermal stability of hydroxyapatite matrix as well as on the phase composition and mechanical properties of the composite materials produced.

Performance of hydroxyapatite material in a living body depends on a number of factors. Stability of hydroxyapatite structure, which is influenced by both, preparation conditions of the starting precursor powders and fabrication method of the implant materials, is an important one. Inappropriate preparation conditions of synthesis, calcination of powder and sintering of formed samples result in dehydroxylation and even in decomposition of HAp which lead to the change in the physicochemical properties of implants. In the work samples of hydroxyapatite ceramics have been obtained by two methods, i.e. by hot pressing and by pressureless sintering in the temperature range of 1150–1300 °C. The materials prepared have been studied using FTIR and XRD in order to identify the dehydroxylation processes and the possible hydroxyapatite decomposition during thermal treatment. The usefulness of both methods in identification of thermal stability of hydroxyapatite was confirmed.

Applicational properties of HAp–ZrO2 composite coatings prepared on a titanium alloy substrate using plasma spraying method and analogous HAp coatings are compared. Results of the studies indicate that there is a strong dependence of the phase composition, thickness, porosity and adhesion to the substrate of the obtained coatings on the characteristics of the starting powders used for their preparation.

During the production of biomedical hydroxyapatite–zirconia (HAp–ZrO 2 ) composites new phases which determine the biocompatibility of implant materials may occur in the system. These phenomena may be associated both with the phase decomposition of hydroxyapatite itself and the interactions between the matrix material and particles of reinforcing zirconia phase. The work deals with the investigations of phase stability of HAp–ZrO 2 composites at high temperature. The composites studied have been in the form of dense sinters obtained by the hot pressing process.

Composite samples were obtained from hydroxyapatite powder and carbon fibres by hot pressing at 1100°C and 25 MPa for 15 min in argon atmosphere. Two types of cut carbon fibres produced in a carbonisation process of polyacrylonitrile (PAN) precursor were used both in non-coated or coated form. The coatings of calcium phosphate were applied by sol–gel technique. The highly sintered composite with the best strength properties was obtained from coated carbon fibres with basic character of the surface. The existence of hydroxyl groups on fibre surface makes possible formation of bonds with the calcium phosphate layer formed as a result of polycondensation following the sol–gel procedure.