Synthesis of masked 2-amino-6-methyl-4-oxo-4H-pyran-3-carbaldehydes

Acetoacetylation of (1,3-dimethylbenzimidazol-2-ylidene)-, (3-methylbenzothiazol-2-ylidene)-, and (3,4-dimethylthiazol-2-ylidene)acetonitriles with 2,2,6-trimethyl-4H-1,3-dioxin-4-one was found to yield appropriate C-acylation products. Treatment of the obtained products with perchloric acid afforded 2-(2-amino-6-methyl-4H-pyran-4-one-3-yl)substituted quaternary azolium salts. Their reduction with sodium borohydride yielded the corresponding dihydro (in the case of benzoazoles) or tetrahydro (in the case of thiazole) derivatives, which were shown to be synthetic equivalents of the title aldehyde

Carcass Compound Materials Base on Fluoropolymer for Tissue Engineering in Orthopedics

In this work new type of composite materials for application as coatings for intramedullary implants in the field of orthopaedics and traumatology is offered. Method is based on ability of fluoropolymers to act as biologically inert binding agent and ability of fine-dyspersated hydroxyapatite powders to act as biologically active filling agent providing osteoinduction and osteoconduction processes. Results of investigations of adhesion, elastic and morphometric characteristics of offered composite were presented; chemical composition was determined. Estimation of toxicological properties, locally irritant action and hemolytic activity of offered composites was done according to GOST R ISO 10993. In vivo tests were carried out; it was shown that offered composites didn’t cause any negative tissue reactions and stimulated osteogenesis processes in ectopic bone formation test. Key words: Carcass Compound Materials; fluoropolymers; orthopaedi

Surface Modification of Polylactic Acid Films by Atmospheric Pressure Plasma Treatment

A new approach for the modification of polylactic acid (PLA) materials using atmospheric pressure plasma (APP) is described. PLA films plasma exposure time was 20, 60, 120 s. The surface morphology and wettability of the obtained PLA films were investigated by atomic force microscopy (AFM) and the sitting drop method. The atmospheric pressure plasma increased the roughness and surface energy of PLA film. The wettability of PLA has been improved with the application of an atmospheric plasma surface treatment. It was shown that it is possible to obtain PLA films with various surface relief and tunable wettability. Additionally, we demonstrated that the use of cold atmospheric pressure plasma for surface activation allows for the immobilization of bioactive compounds like hyaluronic acid (HA) on the surface of obtained films. It was shown that composite PLA-HA films have an increased long-term hydrophilicity of the films surface

Influence of the high-power ion-beam irradiation of a hydroxyapatite target on the properties of formed calcium phosphate coatings

The physical-mechanical of properties of biocompatible calcium phosphate coatings deposited onto titanium and silicon substrates from erosion materials, which are generated by irradiating hydroxyapatite (synthetic and natural) targets by means of the high-power pulsed ion beam of a Temp-4 accelerator, are investigated. A calculation technique for predicting the rate and energy efficiency of deposition using pulsed ion beams is proposed. Their characteristics are analyzed as applied to the formation of calcium phosphate coatings

PLLA scaffold modification using magnetron sputtering of the copper target to provide antibacterial properties

Using the electrospinning method, we produced biodegradable scaffolds from poly-l-lactide acid polymer (PLLA - poly-l-lactide acid). Using DC magnetron sputtering of the copper target we modified the surface of the scaffolds. For investigate scaffolds morphology, structure and elemental composition were used scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis. The results of scanning electron microscopy reveal that scaffolds consist of chaotically located fibres. The diameters of fibres range from 0.8 to 2 μm. Initially amorphous scaffold after modification has crystalline structure. The count of oxygen and copper with modification is increased, but count of carbon decreased. For the investigation of the scaffolds wetting ability were used glycerol and water. The wetting angles for the both liquids were similarly comparable. The values for the wetting angles range from 114 ± 5° to 125 ± 5°, what indicated that scaffolds had hydrophobic properties. Testing for antibacterial features indicated that the modified scaffolds are capable to have a bacteriostatic effect. Compared to the number of bacteria cultured without scaffold (11.8 ± 1.26 CFU×104/ml), two modified samples have bacteriostatic properties (reducing the number of bacteria on 30 and 50%). Economically effective method PLLA scaffolds modification could be used for creating low-cost wound dressings with antibacterial properties

Comparison of titanium mesh implants with PLA-hydroxyapatite coatings for maxillofacial cancer reconstruction

Since 2013 physics of TPU and oncologists from the TCRI with participation of the “ConMet” company (Moscow) and the “Sintel” company (Tomsk Special Economic Zone resident) have been working on the theme entitled “Development of the composite implants for reconstructive surgery of a craniofacial areas of the traumatological and oncological patients” supported with the Federal Program ”R&D, part 1.3”. The goal was to develop the maxillo-facial implants on the basis of the transformable titanium mesh with PLA & hydroxyapatite coating. According to the Contract No. 14.578.21.0031, the team of developers had to start supplying these advanced implants to the industrial partners up to 2017. This research was supported with the preliminary market researches by the ISPMS SB RAS and the TP “MF”. The stages of preliminary market researches were: 1) research of the Worldwide CMF market; 2) forecasting the BRIC CMF market up to 2020; 3) the total Russian market (epidemiology) estimation as a sum of official calculations and statistics; 4) looking for the best foreign analogue prices, comparing their and our implant properties; 5) search for the best Russian analogues; 6) the investigation of the world patent databaseEspacenet for the last years, and finding the owners and applicants of patents of CMF osteosynthesis plates on the basis of titanium coated with PLA & hydroxyapatite; 7) comparison of the domestic implants, and making conclusions. Several variants of the meshes have got the equal quality with the best foreign and Russian implants. The closest analogues were titanium, polyethylene, PEEK composite meshes suited to the patient shape by the Synthes company in 2014, and the only hybrid titanium "Grey" implant with layers of gelatin, dextran, collagen, HAP & BMP-2 was found. This implant was produced by Russian institution, and it was mentioned in the report on clinical trials by L.A. Pavlova et al., 2014 [1]. There are no manufacturers of the coated implants in Russia. The average price of the similar foreign implants varies from 12 up to 4

Comparative Studies of the Physical, Mechanical and Chemical Properties of Hybrid Coatings for Medical Implants

In the work the physical, mechanical and chemical properties of oxide and calcium-phosphate coatings formed by the microarc oxidation and radio-frequency magnetron sputtering methods, or their combination were studied. It is shown that combining the advantages of various technologies enables one to obtain a wide range of hybrid coatings used for various strategies of osteosynthesis. The calcium phosphate coatings obtained by the radio-frequency magnetron sputtering methods were chosen as coatings on cortical screws. The hybrid coatings obtained by a combination of microarc oxidation method and radio-frequency magnetron sputtering method were recommended for intramedullary implants. For extramedullary implants, the most optimal coatings are the coatings formed by radio-frequency magnetron sputtering with an intermediate TiO[2] sublayer

Modification of the zirconia ceramics by different calcium phosphate coatings:comparative study

The aim of this study was to characterize different calcium phosphate coatings and evaluate in vitro cell response of these materials to ceramics implants. The physical and chemical properties of calcium phosphate coatings formed by RF-magnetron sputtering of calcium phosphate tribasic, hydroxyapatite, calcium phosphate monobasic, calcium phosphate dibasic dihydrate and calcium pyrophosphate powders were characterized. Cell adhesion and cell viability were examined on calcium phosphate coatings using mesenchymal stem cells. The results of cytotoxicity measurements of the calcium phosphate coatings revealed that only the coating obtained by RF-magnetron sputtering of the calcium phosphate dibasic dihydrate and calcium phosphate tribasic powders possessed lower cell viability than the zirconia substrate. The coating formed by sputtering of the calcium phosphate tribasic powder demonstrated more cells adhered onto its surface compared with other calcium phosphate coatings

Fundamental Solutions in Plane Problem for Anisotropic Elastic Medium Under Moving Oscillating Source

In present article we consider the problems of concentrated point force which is moving with constant velocity and oscillating with cyclic frequency in unbounded homogeneous anisotropic elastic two-dimensional medium. The properties of plane waves and their phase, slowness and ray or group velocity curves for 2D problem in moving coordinate system are described. By using the Fourier integral transform techniques and established the properties of the plane waves, the explicit representation of the elastodynamic Green's tensor is obtained for all types of source motion as a sum of the integrals over the finite interval. The dynamic components of the Green's tensor are extracted. The stationary phase method is applied to derive an asymptotic approximation of the far wave field. The simple formulae for Poynting energy flux vectors for moving and fixed observers are presented too. It is noted that in the far zones the cylindrical waves are separated under kinematics and energy. It is shown that the motion bring some differences in the far field properties. They are modification of the wave propagation zones and their number, fast and slow waves appearance under trans- and superseismic motion and so on.Comment: 19 pages, Proceeding of the Conference "Advanced Problems in Mechanics", Russia, St.Petersburg (Repino), June 22-July 2, 200