Modified polycarbonate urethane: synthesis, properties and biological investigation in vitro.

A new polycarbonate urethane (PCU-I) was synthesized from aliphatic monomers, i.e. polyhexamethylene carbonate diol and 4,4'-methylene-bis cyclohexane diisocyanate, a mixture of low molecular diols, and castor oil (containing mainly the triglyceride of 12-hydroxyoleic acid). The second synthesized polymer (PCU-II) did not contain castor oil. Both PCUs had good tensile strength, i.e. 32.5 and 27.8 MPa for PCU-I and PCU-II, respectively. Modification by castor oil led to a decrease in glass transition temperature (T(g) = -14 degrees C for PCU-I and -6 degrees C for PCU-II) and an increase in the softening temperature (135 and 125 degrees C for PCU-I and PCU-II, respectively). Partial crosslinking of PCU-I increased the storage modulus of elasticity and provided better resistance to sterilization by ETO and gamma radiation. Both PCUs displayed good stability when subjected to sterilization by hydrogen peroxide plasma. Neither PCU caused cytotoxic effect in mouse fibroblasts (3T3 Balb C). They also had no toxic effects on the morphotic components and did not influence changes in the hematologic parameters or plasmatic coagulation system of human blood.

Influence of plasma modification on biological properties of poly(ethylene terephthalate).

Poly(ethylene terephthalate) film was modified with argon or perfluorohexane plasma to obtain hydrophilic or hydrophobic surfaces, respectively. Various biological experiments in vitro and in vivo were chosen in order to evaluate the influence of such treatment on biocompatibility. Plasma modification does not cause toxic effects and does not influence disadvantageously the tested polyester biocompatibility. The huge changes in surface energy cause only minor changes in the biological behaviour of the samples.

[Comparative studies in vitro of the toxic effect of water extracts from synthetic materials in biological tests on living cells]. / Badania porównawcze in vitro dzialania toksycznego wyciagów wodnych z tworzyw sztucznych w testach biologicznych na zywych komórkach.

Synthetic materials for medicine and pharmacy described as medical grade materials are constantly improved and new materials appear every year. There are various kinds of synthetic materials within the same group and they differ in qualitative and quantitative choice of chemical compounds used for their synthesis, and in technology of their production. These factors influence physico-chemical and biological properties of the materials. There is also a possibility of qualitative changes in synthetic products caused by depolimerization and migration of chemical compounds which depends on the conditions and time of their storage, and on the method of sterilization. The production of a new synthetic item is connected with the necessity of selective choice of the proper material. The choice is made on the basis of complex physico-chemical and biological investigations. Systematic controls of multimolecular materials after polimerizations and controls of ready products should be made in the course of series production. Controls of toxicity are usually made according to chosen one or few biological testing methods in vitro. The results of parallel investigations performed according to different methods are not sufficient for univocal evaluation of the material since they can be either divergent or contradictory. Therefore new tests and expanding methods of biological investigations are constantly looked for. A new technique of synthetic materials toxicity evaluation with the fresh diluted bulls semen has been developed after for several years, of research. The results indicated that the bulls semen was useful in toxicity evaluation. This present work constitutes a continuation and recapitulation of the investigations which had the following goals to be attained. 1. Improvement of investigations technique, development of the criteria of results evaluation and presentation of the basic principles of our method of toxicity investigation of synthetic materials water extracts on the bull semen. 2. Evaluation of the toxicity of various synthetic products used in animals insemination and biomedical products on bull semen. 3. The comparison of the results of toxicity investigation of synthetic materials water extracts on bulls semen with the results of investigations performed on cell cultures HF, mouse cells L929, chicken embryo cells CEC and the results of hemolytic test. 4. The complex evaluation of the own method of toxicity investigation of synthetic materials water extracts with the application of the fresh bulls semen. 55 various materials and products used in medicine, in animals insemination and in the food industry were chosen for the investigation.(ABSTRACT TRUNCATED AT 400 WORDS)

[Experimental testing of the hydrogel dressing Geliperm]. / Badania doswiadczalne hydrozelowego opatrunku Geliperm.

The dressing materials used in the local treatment for dressing large defects of skin, subcutaneous and muscular tissues do not have the optimum protective and therapeutic properties. We carry out experiments tending to achieve new kinds of dressing impermeable for microorganisms, free from toxic, allergic, action and acridity and not evoking pathological tissue reaction in a long-lasting contact with the wound. What is more, the new dressing should hasten the cicatrization process of a wound and enable its control as well as soothe the pain if it is possible. Some of these properties were achieved by the usage of cross-linked hydrophilic polymers with high ability of water absorption, creating elastic gels in its presence. The dressing of this type called Geliperm was produced by Geistlich Sons Ltd. and BYK Goldbin-Konstanz firms. The methods of evaluation of hydrogel dressing materials comprising a preliminary, standard and qualifying evaluation were worked out in the Department of Experimental Surgery and Biomaterials Research Medical Academy of Wroclaw. According to the worked out scheme of experiments the Geliperm dressing was evaluated. We have discovered on the basis of the carried out experiments that the new generation of gel dressing has, to a large extent, the properties of the so called "ideal dressing".

[Testing tissue reactivity to surgical sutures using a personal point method]. / Badanie odczynu tkanek na nici chirurgiczne z zastosowaniem wlasnej metody punktowej.

In the Institution of Experimental and Biomaterial Research Surgery of Medical Academy in Wroclaw works on biological methods of estimation of different biomaterials including, first of all, surgical threads have been carried out for 30 years. The purpose of this work is to define the local biological reaction on the implanted absorptive and non-absorptive surgical threads. The present estimation of reactivity of surgical threads depended on a description of a great number of histological samples and on observation of numerous microscopic fields for each tested thread. It required long and tiring descriptions the analysis of which was made difficult and often led to non-objective conclusions. The presented punctual system depends on observation of the field of vision in a biological microscope which includes transverse cross-section of the implanted thread together with the surrounding tissues. The estimation of the histological samples in magnification of 45 times allows to define the range of infiltration of tissues with inflammatory cells in comparison with the diameter of the implanted thread. Observations in magnification 120 times allow to differentiate cells included in non-specific inflammatory process. The worked put punctual system enables to define the level of tissue reaction on the basis of uniform criteria.

[Influence of materials with different hydrophobic properties on selected parameters of blood coagulation]. / Wplyw materialów o róznym stopniu zwilzalnosci na wybrane parametry ukladu krzepniecia.

In this paper we presented the evaluation and assessment of the influence of the knitted polyester materials with the different hydrophobic properties of theirs surfaces on the blood coagulation and fibrinolysis investigated on dynamic "in vitro" model. On the basis of the received results we can stated that the material with hydrophobic surface do not change the coagulation time in the internal-factors model nor in the external-factor model. It also has no influence for the concentration of fibrinogen, activity of the factors XII and VIII, antithrombin III, protein C nor for plasminogen. The knitted material with the hydrophilic surface increased the coagulation time while use in internal-factors model but do not change the coagulation time in the model with external-factors. It also has the influence in decreasing the activity of the factors XII and VIII. The activity of blood coagulations' inhibitors and plasminogen remained not changed.

[Effect of plasma modification on biological properties of polyethylene terephthalate foil]. / Wplyw modyfikacji plazmowej na wlasciwosci biologiczne folii z politereftalanu etylenowego.

Film of poly(ethylene terephthalate) modified with plasma of pure argon and with mixture of argon and perfluorohexane. Wettability of surface, toxic influence, reaction of tissues and influence on the blood-clotting system of modified samples were tested. Plasma was modification allowed to obtain PET both with hydrophilic and hydrophobic surface. We did not observed the increase of toxicity and of the reaction of tissues in comparison with the initial film. Modification with plasma of perfluorohexane had the test influence on the blood-clotting system.

[Experimental studies of new Polish hydrogel dressing materials HDR]. / Badania doswiadczalne nowych polskich opatrunków hydrozelowych o symbolu HDR.

Recently the spectrum of dressings was enriched, incorporating the so-called hydrogel dressing, made by Geistlich Sons Ltd. and Byk Goldbin-Konstanz referred to as "Geliperm". In Poland, HDR hydrogel dressings' technology was launched by Institute of Radiative Technology, Lódz+ Polytechnic. This type of dressing is obtained by radiative cross-linking of hydrophilic polymers. The experimental studies of the new Polish hydrogel materials were accomplished at the Department of Experimental Surgery and Biomaterials Research, the Chair of traumatologic Surgery, Medical Academy of Wroclaw. These studies concerned three kinds of hydrogel dressings, different in composition and irradiation conditions. HDR-1 10% of polyvinylpyrrolidone+, 1.5% of agar, 1.5% of polyethylene glycol 300, irradiated with 30 kGy (gamma radiation of 60Co); HDR-1 with neomycin--formula as above plus neomycin sulfate (2.5%); HDR-2 6% of polyvinylpyrrolidone++, 1% of agar, 1.5% of polyethylene glycol 300, irradiated with 25-27 kGy (gamma radiation of 60Co). The usable properties of the HDR dressings approximate those of the West German products. Owing to the lab tests, biological and in vitro examinations we had performed, it was possible to state that aqueous extracts of the hydrogel dressings subjected to assessment did'nt exhibit hemolytical or toxic activities in cellular tests, at the same time lacking an irritating effect. They cause a minimal tissular reaction and accelerate the process of healing.

[Attempts at modification of the polyester vascular prosthesis]. / Próby modyfikacji poliestrowych protez naczyniowych.

Polyester vascular bilaterally velour prostheses produced by the Enterprise of Medical Products TRICOMED in Lodz were modified through: putting negative electric charge on the internal surfaces of prostheses; additional cleaning with ethanol; covering of the surfaces of prostheses with silicone preparation; two-sided covering of the surfaces of prostheses with collagen by the radiative method; covering of the surfaces of prostheses with chitosane. Laboratory investigations, investigations of hemolytic and toxic effects of aqueous as well as experimental investigations has been carried on piglets. During these investigations it was observed that the carried preparations caused multiple increase of electrical conductivity of proper and dry remnant after evaporation of the aqueous extracts. Hemolytic and toxic effects were not observed. In radiological and pathomorphological investigations it was observed that none of the preparations used for modification of vascular prostheses influenced improvement of their biological properties. In comparison with the initial prostheses DALLONR these prostheses evoked a greater reaction of tissues which was manifested with a thick internal layer causing narrowing of the lumen of the section with prosthesis or closing it. A small improvement of the biological properties of the prostheses were achieved after cleaning them with methanol. However, this improvement is so small that it does not justify changes in the existing technology.

[Absorption of chitosan applied to polyester discs in rats after implantation]. / Wchlanianie chitozanu naniesionego na krazki poliestrowe po implantacji u szczurów.

Experiments have been made on white rats implanting polyester blocks covered with chitosan into the peritoneal cavity and to the abdominal wall skin. Before implantation the material was sterilized with ethylene oxide or radiation. The animals were subjected to autopsy 3, 7, 14, 21, 25, 30, 35, 40, 45, 50, 55 and 60 days after implantation with macroscopic and microscopic evaluation. On the basis of the carried out experiments it was stated that the disintegration of chitosan proceeded not uniformly. The resorption time of chitosan oscillated in the range of 45-60 days and it was accompanied by rather strong specific inflammation process. It was characterized with fibrin effusion and with appearance of multi-flapped neutrocytes. Essential distinctions in the resorption process of depending on the sterilization mean of the blocks as well as on the place of implantation were not stated.

[Experimental testing of hydrogel dressings POLGEL based on the basis of synthetic monomers]. / Badania doswiadczalne opatrunków hydrozelowych POLGEL opartych na bazie syntetycznych monomerów.

In the Department of Experimental Surgery and Biomaterials Research in Wroclow Medical Academy standard and qualifying evaluation of 5 kinds of hydrogel dressings POLGEL produced in the Institute of Physico-Chemistry and Technology of Polymers of produced in Silesian Polytechnique has been carried out. Dressings Polgel were obtained as a result of copolymerization of acrylamide and methylene-bis-acrylamide in aqueous solution. On the basis of introductory experiments for qualifying evaluation dressing Polgel M modified with glycerin in the form of foil and dressing Polgel T--in the form of jelly were chosen. Both kinds of dressings did not cause haemolytic, toxic or irritative effects. In pathomorphological experiments moderate tissues reaction was noticed what signifies good biological characteristics of the evaluated dressings. The process of healing of injuries treated with dressings Polgel M proceeded well and epidermis creating was quicker in comparison with injuries treated with traditional dressing. On the basis of the carried out experiments it was noticed that dressings Polgel M and T satisfy the requirements made for the type of materials.

[Usefulness of selected parameters from the diagnostic laboratory for evaluating absorbed grafting materials]. / Przydatnosc wybranych parametrów z diagnostyki laboratoryjnej do oceny wchlanialnych materialów implantacyjnych.

The results of hematologic, biochemical research and research of clotting system after intraperitoneal implantation of absorbed synthetic threads Dexon S are presented in this work. The research was made on rats of Wistar type. Blood for the research was taken 3, 7, 14, 30 and 60 days after the implantation. Morphology (Ht, Hb, MCH, WBC, the number of platelets), activity of aspartic and alanine aminotransferase and antithrombin activity, concentration of comolete protein and its fraction and concentration of glucose, urea, creatinine and also concentration of ions Na+, K+, Mg2+, Ca2+ and fibrinogen, protein C3 and C4 of complement system as well as kaolin-kephalin time and prothrombin time of plasma were marked. On the basis of the obtained results of the research it was noticed that the used methods of research constitute supplement of biological estimation of absorbed grafting materials.

[Changes in the level of selected laboratory parameters in blood after implantation of chitosan fibers]. / Zmiany w poziomie wybranych parametrów laboratoryjnych krwi po implantacji wlókien chitozanowych.

The tests were carried out on rats of the Wistar tribe to the peritoneal cavity of which chitosan fibres were implanted. The blood for the tests was taken in 3, 7, 14, 30 and 60 days after the implantation. In the blood hematological, biochemical and clotting system parameters were marked. Moreover they made pathomorphological tests of the tissues surrounding the implanted material and laboratory and biological tests of aqueous extracts from chitosan fibres. The shown quantitative changes in the level of the marked parameters of blood to the 14th day of observation are connected mainly with toxicity of chitosan fibres, whereas to the 30th and 60th day-with the process of biodegradation and resorption of collagenous fibres.

[Changes in the level of interleukin-1 beta and interleukin-6 after implantation of selected medical materials. Introductory report]. / Zmiany w poziomie interleukiny-1 beta i interleukiny-6 po implantacji wybranych materialów medycznych. Doniesienie wstepne.

Evaluation of biomaterials with the help of routine methods not always allow full and explicit stating of their toxicity. That is why we still seek new methods of evaluation of biocompatibility on the cellular level. Usage of changes in activity of interleukin after biomaterials implantation creates such a possibility. The aim of this work as use of changes in activity of cytokines IL-1 beta and cytokines IL-6 for evaluation of biocompatibility of chosen medical materials. The tests were made on mice to whom polyester and aramid fibres as well as discs of rubber drains were implanted into the peritoneal cavity. Evaluation of the changes of the level of interleukin-1 beta and interleukin-6 was made in the fluid from the peritoneal cavity 3, 7, 14 and 21 days after implantation. Introductory tests of changes in the level of IL-1 beta and IL-6 after implantation of biomaterials with different degree of biocompatibility allow to assume that testing their activity may be useful in evaluation of their toxic effect.

The biological assessment of the chitin fibres.

On the basis of carried laboratory tests of the aqueous extracts, such as pH evaluation, electric conductivity and dry residue assessment we can stated that the obtained results are within the limits of the standards and are comparable to these given for similar kinds of medical devices, e.g. for Dexon sutures: pH--6.10; electric conductivity--31 MicroScm-1; dry residue after evaporation--0.0014 g/100 cm3. The mean percentage of hemolysis counted from the three samples made for chitin extracts was 0.86% and did not exceed the value of 1% which is accepted by the standards. In the assessment of the cytotoxicity which was carried out on the mouse fibroblasts, the proper morphological character was stated. Agglutination, vacuolisation, nor cells membrane lysis were not observed. The number of cells separated from the matrix were identical as in the control cultures. The increased number of the dead cells and decreased proliferation of the cells in the cultures containing the chitin extracts, were probably due to the ethylene oxide residues, which was used for sterilisation of the fibres. The assessment of the intracutaneous reactivity of the chitin extracts showed the lack of the irritation influence and the index of primary irritation was of no importance at all. The pathomorphological findings, which included macroscopic and microscopic evaluation, specially carried out after the implantation, showed the greater biocompatibility of the tested chitin fibres in comparing them to the Maxon sutures. The healing process of these fibres included the short exudative phase, which was more significant than in Maxon sutures reaction followed by the proliferation phase, which ended with the development of the connective tissue capsule. The connective tissue penetrated among the single chitin fibres. After longer observation periods (more then 30 days) the thickness of the capsule decreased. The number of the chitin fibres did not change over the observations periods, however the change of the colour of the fibres was observed. In our opinion it is the sign that the process of resorption has already started. The tissue reactions after implantation of the chitin fibres can be compared to those observed for monofilament suture Maxon. On the basis of all these observations, assessments and findings we can stated that the chitin fibres fulfil the basic biological requirements set up for the bio-medical devices.

[Tissue reaction to implanted polyurethane designed for parts of the artificial heart]. / Odczyn tkanek na implantaty poliuretanowe przeznaczone na elementy sztucznego serca.

Experiments on producing polyurethane membranes which could be used for elements of an artificial heart have been carried out in Poland for several years. In the Institute of Biocybernetics and Biomedical Engineering PAN in Warsaw two kinds of polyurethanes with symbols PU 47 and PU 90 have been worked out. They differ in physicochemical properties and they were subjected to investigations of tissue reaction in the Institute of Experimental Surgery and of Biomaterials Investigations of the Medical Academy in Wroclaw. The investigations were carried out on 70 rats of the Wistar breed and on 30 rabbits of the New Zealand breed. Polyurethane circles were implanted into subcutaneous tissue, to peritoneal cavity and into muscles of the back in rats; polyurethane oars were implanted into muscles of the back along the backbone of the rabbits. Sections of the animals were carried out 3, 7, 14, 28, 90 and 180 days after the surgery taking 5 animals in each term. Macroscopic and microscopic as well as physicomechanical investigations were carried out. The carried out experimental investigations of the both kinds of polyurethanes showed good tolerance of the animals' organisms on the implanted material. Summing up, we can say that the tested polyurethane foils with symbols PU 47 and PU 90 satisfy the basic requirements made on the materials designed for temporal contact with a living organism.

[Biological tests of sol-gel biomaterials]. / Badania biologiczne biomaterialów zol-zelowych.

Recently, the sol-gel based biomaterials are extendedly investigated in emphasis on theirs medical applications. In this respect it is important to investigate the influence of sol-gel matrices on biological systems. The results of laboratory and biological testing of water extracts of sol-gels are presented in this work. It was proved that it is possible to construct the sol-gels that are not cytotoxic for which the haemolytic reactions fulfils the foreseen norms. This can be achieved by heating the materials in certain temperatures (higher than 350 degrees C). This effect can also be reached by suitably long aging (minimum 6 months).

[Biocorundum--a new/type of poreless ceramic material of aluminum oxide for the manufacture of the elements of hip joint prosthesis. Biological and technological studies]. / Biokorund--nowa odmiana bezporowatego spieku ceramicznego z tlenku glinu--przeznaczona do wyrobu elementów endoprotez stawu biodrowego. Badania biologiczne i technologiczne.

The Institute of Refractories Materials in Gliwice undertook researches in the field of technology of a new ceramic material of aluminium oxide for production of coxal joint endoprostheses. A poreless ceramic material of high chemical purity and density and required microstructure and good resistance to fracture, was achieved. The new ceramic material was called Biocorundum. By means of a similar technology also series of samples were produced for testing the biocompatibility of the material. Biological studies were carried out in the Department of Experimental Surgery and Biomaterials Research, Chair of Traumatologic Surgery, Medical Academy of Wroclaw. The studies comprised: 1. laboratory and toxicological tests in vitro of water extracts, 2. pathomorphological studies after intramuscular, peritoneal and intra-bone implantation of samples of the material in rats and piglets, 3. ultrastructural scanning studies of the implantation in rats and pigs and after 3- and 6-months long keeping in the Ringer solution. Preliminary studies and biological studies in vitro have shown a complete conformity of the material with the requirements. Tissue reactivity was studied on 36 Wistar rats. By pathomorphological studies a systematic macroscopic and microscopic estimation was possible. They have shown only minimal tissue reactivity to biocorundum implantation. In experimental studies on 14 piglets the biocorundum grafts were implanted into the tibia epiphysis for 3- and 6-months. Clinical, pathomorphological and X-ray studies were carried out. In all cases the Biocorundum grafts healed without any complications. On the basis of pathomorphological studies, the tissue reactivity around the grafts were estimated as minimal. This shows a high biocompatibility of the ceramic material. In X-ray studies were observed around the grafts small osteosclerotic changes and periosteum stratification. These changes resulted after surgical interventions in quickly growing piglets. Complementary studies of the surface of the material by scanning microscopy after 3 months long implantation and after 3 months long contact with the Ringer solution did not show any changes in comparison with the surface of the initial samples. After 6 months long implantation in individual samples rounding of the ceramic material grain edges were found, which could result from biological corrosive power. This agree with the findings of other studies on other ceramic aluminium oxide materials. The achieved results of complex studies of biocompatibility of the new poreless material developed in Poland--Biocorundum--have shown its complete biological suitability for production of elements of osteoarticul