Bactericidal and biologically stable coatings for medical implants and instruments

The experimental research showed the fine-film coating based on hafnium nitride to inhibit the pathogenic microflora and to exert the bactericidal effect by far less versus that of antibiotics; at the same time, the concentration of hafnium ions in the solution is just within the sensitivity limit detectable by the most recent registration methods--it amounts to less than 10(-10) mol/l. Therefore, according to the research results, the use of such coatings based on hafnium nitride is promising in manufacturing the surgical metal implants and medical instruments.     

Diffusion-transport properties of a polycomplex matrix system based on eudragit<Superscript>®</Superscript> EPO and Carbomer 940

New interpolyelectrolyte complexes (IPEC) between Eudragit^? EPO (EPO) and Carbomer 940 (C940) were synthesized for assessment as controlled-release delivery carriers for oral systems. Depending on the structural properties, the resulting IPEC were distinct from the individual (co)polymers and their physical mixtures in terms of their swelling profiles in media simulating the gastrointestinal tract. Changes in structure and composition occurring within the polycomplex matrix on swelling were studied by IR spectroscopy, MT-DSC (modulated temperature differential scanning calorimetry), and elemental analysis. The mechanism underlying the transport of the model drug ibuprofen from the polycomplex matrix was identified.     

Synthesis and characterization of a new carrier based on Eudragit® EPO/S100 interpolyelectrolyte complex for controlled colon-specific drug delivery

With a view to the development of peroral controlled drug delivery systems, a new interpolyelectrolyte complex (IPEC) between oppositely charged types of Eudragit?, EPO and S100, has been synthesized and investigated at neutral pH values. According to data of turbidimetry, capillary viscometry, gravimetry, and elemental analysis, the obtained IPEC has a composition of Z = [EPO]/[S100] = 1.26. Structural features of the IPEC samples have been evaluated by FTIR spectroscopy and modulated-temperature differential scanning calorimetry. The results confirmed that the IPEC is stabilized by cooperative intermacromolecular ionic bonds, is chemically homogeneous, and is characterized by a single glass transition temperature. The observed features of the carrier swelling and diclofenac sodium release from the matrix system confirm that the proposed IPEC has great potential to be used as a carrier for controlled colon-specific drug delivery.     

Biopharmaceutical assessment of a polycomplex matrix system based on carbomer 940 and Eudragit<Superscript>®</Superscript> EPO for colon-specific drug delivery

The biopharmaceutical properties of a new drug carrier based on an interpolyelectrolyte complex (IPEC) between Carbomer 940 and Eudragit^? EPO have been studied in the form of a polycomplex matrix system (PMS) intended to be a potential carrier for peroral drug delivery systems. The release profiles of diclofenac sodium from the proposed PMS and Voltaren^? retard in model gastroitestial tract medium belong to the intestine-soluble and sustained-release types, respectively. Evaluation of the pharmacokinetic parameters of the PMS revealed a close in vitro/in vivo correlation. The proposed PMS, in contrast to the parent drug, provides targeted drug delivery to the colon region and is comparable with Voltaren^? retard with respect to the bioavailability and the main pharmacokinetic parameters.     

Synthesis and physicochemical evaluation of a new carrier based on an interpolyelectrolyte complex formed by Eudragit® EPO and Carbomer 940

The formation of interpolyelectrolyte complexes (IPEC) between Eudragit^? EPO (EPO) and Carbomer 940 (C940) was investigated with a view to their use in peroral controlled-release drug delivery systems. The structure of the synthesized products was investigated using FTIR spectroscopy and MT—DSC methods, which indicated that the synthesized product can be considered to be an IPEC stabilized by a cooperative system of ionic bonds. Based on results of capillary viscosimetry and elemental analysis, the IPEC prepared at pH 4.0 has a characteristic composition with a C940:EPO mole ratio of 1.75:1.     

New poly-imidazolium–triazole particles by CuAAC cross-linking of calix[4]arene bis-azide/alkyne amphiphiles – a prospective support for Pd in the Mizoroki–Heck reaction

A new imidazolium amphiphilic calix[4]arene with terminal acetylene fragments in the polar region was synthesized according to a two step scheme including regioselective chloromethylation of distal di-O-butyl calix[4]arene and subsequent interaction with 1-(hex-5-yn-1-yl)-1H-imidazole. The aggregation properties (CAC, the size and zeta potential of aggregates) of alkynyl calix[4]arene as well as of previously synthesized azidopropyl calix[4]arene and their 1 : 1 mixture were disclosed. Macrocycles with azide and alkyne fragments in the polar region were covalently cross-linked under CuAAC conditions in water. Successful cross-linking of molecules has been proven by IR spectroscopy and MALDI-TOF spectrometry. The obtained polymeric particles were studied both in solution and the solid state and the presence of submicron (∼200 nm) and micron (∼1–5 μm) particles with the prevalence of the latter was found. The average molecular weight of the polymer according to the static light scattering data was found to be 639 ± 44 kDa. The obtained polymeric imidazolium–triazole particles were tested as a support for Pd(OAc)₂ in the Mizoroki–Heck reaction carried out in both organic and water media. In both solvents (especially in water) the addition of imidazolium–triazole particles to Pd(OAc)₂ increased the conversion of 4-iodanisole. It was found that the ratio between the products (1,1 and 1,2-substituted ethylenes) changes drastically on going from DMF to water from 1 : 5 to 1 : 40 when using supported Pd(OAc)₂.

A new supramolecular approach to the formation of polytriazole–imidazolium particles, promising supports for catalysis, based on self-assembly of amphiphilic bis-azides and bis alkynes and their linkage using CuAAC is presented.     

Processing of Dynamic Images during Transurethral Resection of the Prostate Gland

An analytical model of dynamic imaging of the prostate gland during prostate transurethral resection is described. The structure of a system of dynamic image processing for guiding resectoscope motion inside the prostate was developed. A trajectory processing technique for dynamic imaging is suggested and analyzed.