Design of New Concept of Knitted Hernia Implant.

A knitted implant, unilaterally modified with plasma-assisted chemical-vapor deposition (PACVD), and with a nano-layer of fluorine derivative supplementation, for reducing the risk of complications related to adhesions, and the formation of a thick postoperative scar was prepared. The biological evaluation of designed or modified medical devices is the main aspect of preclinical research. If such studies use a medical device with prolonged contact with connective tissue (more than 30 days), biocompatibility studies require a safety assessment in terms of toxicity in vitro and in vivo, allergenicity, irritation, and cancerogenicity, reproductive and developmental toxicity. The ultimate aspect of biological evaluation is biofunctionality, and evaluation of the local tissue response after implantation, resulting in the determination of all aspects of local biocompatibility with the implemented synthetic material. The implantation of PACVD-modified materials in muscle allows us to estimate the local irritation effect on the connective tissue, determining the risk of scar formation, whereas implantation of the above-mentioned knitted fabric into the abdominal wall, assists with evaluating the risk of fistula formation-the main post-surgical complications. The research aimed to evaluate the local reaction of the soft tissues after the implantation of the knitted implants modified with PACVD of the fluoropolymer in the nanostuctural form. The local effect that occurred during the implantation of the designed implants was quantitatively and qualitatively evaluated when PACVD unmodified (reference), and modified medical devices were implanted in the abdominal cavity (intra-abdominal position) for 12 or into the muscles for 56 weeks. The comparative semi-quantitative histological assessment included the severity of inflammatory cells (multinucleated cells, lymphocytes, plasma cells, macrophages, giant cells) and the tissue response (necrosis, neovascularization, fibrosis, and fat infiltration) on a five-point scale. The knitted implants modified by PACVD did not indicate cumulative tissue response when they were implanted in the muscle and intra-abdominally with direct contact with the viscera. They reduced local tissue reaction (score -2.71 after 56 weeks of the implantation) and internal organ adhesion (irritation score -2.01 and adhesion susceptibility -0.3 after 12 weeks of the implantation) compared with the reference (unmodified by PACVD) knitted implant, which had an identical structure and was made of the same source.

Haemocompatibility and cytotoxic studies of non-metallic composite materials modified with magnetic nano and microparticles.

PURPOSE: Preventing the formation of blood clots on the surface of biomaterials and investigation of the reasons of their formation are the leading topics of the research and development of biomaterials for implants placed into the bloodstream. Biocompatibility and stability of a material in body fluids and direct effect on blood cell counts components are related both to the structure and physico-chemical state of an implant surface. The aim of this study was to determine haemocompatibility and cytotoxicity of polysulfone-based samples containing nano and micro particles of magnetite (Fe3O4). METHODS: The polysulfone-based samples modified with nanometric and micrometric magnetite particles were examined. Physicochemical properties of the composites were determined by testing their wettability and surface roughness. The action of haemolytic, activation of coagulation system and cytotoxicity of composites was evaluated. RESULTS: Wettability and roughness of materials were correlated with nanoparticles and microparticles content. In the tests of plasma coagulation system shortening of activated partial thromboplastin time for polysulfone with nano magnetite and with micro magnetite particles was observed in comparison with pure polysulfone. Prothrombine time and thrombine time values as well as fibrinogen concentration were unchanged. Haemolysis values were normal. Morphology and viability of cells were normal. CONCLUSIONS: Composites made from polysulfone modified with nanoparticles and microparticles of magnetite cause neither haemolytic nor cytotoxic reaction. These composites evoke plasma endogenous system activation.

[A method of manufacture and characteristic of surface properties and biological activity of thin-film coatings of Cu-Ti system]. / Sposób wytwarzania oraz charakterystyka wlasciwosci powierzchni i aktywnosci biologicznej cienkowarstwowych powlok ukladu typu Cu-Ti.

BACKGROUND: Biomaterials in the form of thin-film coatings as-deposited on different substrates are nowadays increasingly popular. In particular coatings based on a combination of biocompatible materials (eg. titanium) with metals of high biological activity (eg. copper) have a potentially wide range of applications as active films, intended for various types of medical devices. OBJECTIVES: The aim of this study was to present a method for preparation and analysis of the properties of Cu-Ti thin films, in particular their biological activity in connection with the properties of the surface. MATERIAL AND METHODS: The films were prepared by magnetron sputtering method with the aid of an innovative four-target apparatus. During deposition process two metallic targets (copper and titanium) were sputtered under an argon atmosphere. Material composition of produced coatings was characterized by scanning electron microscope equipped with an adapter for energy dispersive spectroscopy. Moreover, the surface microstructure and roughness of coatings was characterized based on three-dimensional surface profiles, which were obtained with the aid of optical profilometer. The research was also carried out by investigations of surface wettability on the apparatus for measurements of contact angle. Characterization of Cu-Ti surface properties was also expanded by microbiological tests involving Staphylococcus aureus (PCM 2602) bacteria and investigations of cytotoxicity with L 929 (NCTC clone 929) cell line. RESULTS: Measurements have shown that the film was composed of 71% at. Cu and 29% at. Ti. The analysis of surface topography has shown that the surface of Cu-Ti thin film was very uniform with roughness in range of nanometers. It was found that as-deposited film is hydrophilic. Obtained results has shown that as-deposited film had a very good bactericidal properties and it was cytotoxic. This effect was associated with the migration of copper ions, which was the most intense at the edge of the sample. CONCLUSIONS: The results presented in this paper testify that manufactured Cu-Ti thin films may find practical application in the industry as a bioactive coating.

[Studies of interaction between surface of pirolytic carbon and blood cells and proteins]. / Badania interakcji powierzchni wegla pirolitycznego z komórkami i bialkami krwi.

BACKGROUND: Preventing blood clots formation on the biomaterials surface and finding the causes of their appearance are the leading research subjects while working out biomaterials for grafts into the circulation system. Interaction between the biological environment and the carbon implant is closely connected with the properties of its surface. Implants whith surfaces covered with pyrolytic carbon is characterised by athrombogenity have particular significance in medical applications. OBJECTIVES: Assessment of the influence of a pyrolytic carbon surface on the activation of coagulation system. MATERIAL AND METHODS: Full human blood was subjected to temporal contact in vitro with the surface of low-temperature isotropic carbon (LTI). The haemostatic action of pyrolytic carbon was determined through marking the chosen parameters of the coagulation system and the recalcification time on the material surface. The evaluation of the topography of the material was performed in the scanning microscopy. RESULTS: Changes in the values APTT, PT, TT, fibrinogen and activity of factors F XII, F IX, F VIII as well as AT III, protein C and plasminogen were not observed in the studies of the plasmatic coagulation system. The blood coagulation time on the material surface was elongated in comparison with the surface of glass and polystyrene surface. CONCLUSIONS: Direct contact of blood with the surface of carbon LTI elongates clot formation, while not changing the parameters of the plasmatic coagulation system in temporal contact.

The impact of the dibutyrylchitin molar mass on the bioactive properties of dressings used to treat soft tissue wounds.

In this work, we describe a novel technique for producing biocompatible medical products with bioactive properties from the biodegradable polymer dibutyrylchitin (DBC). Materials produced by blowing out polymer solutions have excellent hemostaic properties and are easy to handle during surgery. Biocompatibility studies, encompassing hemostasis and the evaluation of post-implantation reactions, indicate that the biological properties of DBC depend on the molecular mass of the polymer. Lower molecular mass polymers are preferable for use in implanted wound dressings.

Ceramic corundum materials with modified surface as implantation materials.

Investigations on implants have proved that not only the kind of material structure, but also the surface character of grafts influences the local reaction of biomaterials. In recent years electrochemical reactions on implants surface leading to the so called zeta potential arouse interests. Applications of these properties has made us carry on experiments on use of biomaterials with active potential on their bio-compatibility. The aim of this work is evaluation of influence of electrical charge with zeta potentials character on the local reaction of bone tissue after implantation. Two kinds of ceramics were used in experiments: solid and solid-silane with active surface. Implantation experiments were made on 20 rabbits. Selections were carried of 12, 26, 36 and 54 weeks after implantation of the tested materials. After implantation of solid ceramics, not only bone tissue but also fibrous tissue was observed around the graft. But in case of solid silane ceramics, in all terms of tests, bone tissue tightly sticking to the implant was observed around the graft. Investigations of electrokinetic zeta potential carried out 36 and 54 weeks after implantation showed that the values of that potential originally introduced on the grafts surface were maintained on stable level. The carried out investigations confirmed that activation of implants surface through silaning with sol-gel method allows to introduce the planned zeta potential depending on the characteristic for a given kind of tissue.

[Application of elemental microanalysis for estimation of osteoinduction and osteoconduction of hydroxyapatite bone implants]. / Zastosowanie mikroanalizy pierwiastkowej do oceny osteoindukcji i osteokondukcji dokostnych implantów hydroksyapatytowych.

Hydroxyapatite (HAp) ceramics based on calcium phosphates, chemical compounds being natural constructive element of bones is now regarded to be one of better implantation materials in osseous surgery and stomatology. HAp is poorly soluble and slowly resorbing in tissues material. Easiness of connecting of hydroxyapatite ceramics with other materials creates possibilities to produce new composites of chemical compounds containing calcium and easier resorbing. An important and till now not fully known problem is influence of hydrodroxyapatite grafts on the processes leading to production of calcium and phosphorus ions responsive for mineralization of bone tissue around the graft. Proliferation of osteoblasts and rate of osseous trabeculas production depends, among others, concentration of calcium and phosphorus ions. The main target of this study was the comparative analysis of the bone mineralisation rate after implantation of hydroxyapatite (HAp) and composites hydroxyapatite + beta tricalcium phosphate (HAp + TCP) and hydroxyapatite + calcium hydrosulfate (HAp + gypsum), on the basis of elemental microanalysis. Implantation studies were carried out on 24 rabbits. Sections were carried out 5, 9, 11 and 14 weeks after implantation of the tested materials. The carried out punctual analysis of the occurring elements and their topographic location (mapping) in bones after implantation showed essential differences among the tested grafts. Those differences were most significant after 5 and 14 weeks and depended on the rate of the tested materials resorption. On the basis of conducted macroscopic evaluation and scanning microscope assessment we can stated that the composite of HAp+TCP showed the best osteocunductive properties, while the best osteoinductive influence was shown by the composite HAp + gypsum.

[Effect of corundum-vancomycin composite on soft tissue reaction]. / Wplyw kompozytu korundowego z Wankomycyna na odczyn tkanek miekkich.

The ceramics on the basis of corundum is used for implantation in the form of porous and solid materials. The solid form was used to produce tissue endoprosthesis while porous form is mainly used to fill in the bone defects. The corundum ceramics are also known to be used as coatings for implants in orthopedics and dentistry. On the other hand there is still a need to find out the new way of treatment of the chronic bone infection, during which the traditional way of antibiotics therapy is no more effective. One of the possibly solution is to use the different biomaterials as drug carriers and in the bone surgery one of the best are porous corundum implants, being themselves of high biocompatibility, and additionally containing Vancomycin. The main target of the investigation presented in this paper was the comparative assessment of the corundum ceramics and its composite containing Vancomycin after implantation into back muscle of the total of 15 rats. During the post mortem macroscopic assessment in the tissues which surrounded the implants there were no any inflammatory neither pathological changes observed. In the microscopic findings, in early periods, the observed inflammatory tissue reaction for implants with vancomycin was significantly greater what could be explained by the high concentration of the antibiotic in the given material. On the basis of the results of macroscopic and microscopic findings we can state that the composite material of corundum ceramic containing vancomycin is of high compatibility and could be regarded as the good drug carrier.

[The bone reaction to the implantation of the corundum-vancomycin composite]. / Reakcja tkanki kostnej po implantacji ceramiki korundowej z Wankomycyna.

Polymethacrylate methylene (PMMA) used as the carrier for antibiotic gentamycin (Septopal) shows today very limited effectiveness. Only 24% of the staphylococcus strains is still susceptible for it. In 1982 this factor was as high as 97%! Because of the growing resistance of different strains of staphylococcus, enterococcus and G(-) bacillus for antibiotics in present use, came into being the necessity for evaluation of the state-of-the-art antibiotic carrier of the new generation, which should be effective to destroy the resistant strains of bacteria. The porous corundum ceramics proved to be good material for this purpose, specially in use for bone surgery. During the laboratory tests it was confirmed that corundum ceramics could be soaked with the different antibiotics of the new generations. The bacteriological tests proved that corundum ceramics soaked with the Vancomycin show the highest possibly antibacterial activity. On the basis of those results we undertook the implantation test on animals. The implantation was carried out on 10 rabbits in which the samples of tested ceramic with Vancomycin were implanted into femoral bone. The investigation periods were set up for 1, 3, 6 and 9 months. On the basis of received results of macroscopic, microscopic and radiological findings we can stated that corundum ceramic with Vancomycin can be used in the treatment of bone infections.

[Investigation of local reaction of muscular tissue after injection of polyvinylpyrrolidone preparation]. / Badania miejscowej reakcji tkanki miesniowej po iniekcji preparatu poliwinylopirolidonu.

Natural preparations for replenishing of hyaluronic acid of zoogenous origin used till now, are characterized with quit low biocompatibility and also too short effect of their action. Recently worked out synthetic polyvinylpyrrolidone preparation PVP, contains modification constituting internally netting of microgels to improve polymer bioresistance. The introduce modification can, however influence PVP biocompatibility after deposition into tissues of the living organism. The aim of research was evaluation of the local reaction of muscular tissue after PVP infection. The results of research concerned a control group where normal saline was used for infections. The research was carried out on 18 Wistar rats and included macroscopic and histologic observations made in the 3rd, 5th, 7th, 14th and 30th day after PVP injection into thigh muscle. The local reaction of muscular tissue was macroscopically characterized with inflammatory reaction till the 7th day after PVP injection, in later terms the observed changes disappeared. Microscopic research showed that PVP till the 7th day after PVP injection caused rather strong diffuse non-specific inflammatory process, yet without essential participation of neutrophils leading to producing of loose intra-muscular. Connective tissue in a later term. The carried out tests showed presence of PVP in muscular tissue till the 30th day after injection.

[Tissue reaction after injection of polyvinylpyrrolidone (PVP) preparation into knee joint. Experiment]. / Odczyn tkankowy po iniekcji preparatu poliwinylopirolidonu (PVP) do stawu kolanowego. Badania doswiadczalne.

Internally netted miscogelatinated preparation on the basis of polyvinylpyrrolidone PVP desioned for viscosuplementation of joint fluid was worked out. Netted structure of microgel grains presents larger resistance to the degrading action of free radicals than analogical linear polymer chains. Application of zoogeous preparations of hyaluronic acid results in short-term effects of their usage in evoking reaction foreign protein. Replenishment of joint fluid with preparation with higher biostability from biocompatible synthetic polymer-polyvinylpyrrolidone could improve the function of synovial through restoration of its proper viscosity and protection of the joint for a longer period of time. The aim of the experiment was determination of bioresistance and reaction of microgel PVP on the tissues of synovial joint. The tests were carried out on 10 white New Zealand rabbits after injection PVP into the knee joint for 3, 7, 14 and 30 days and submitted to macroscopic and histological evaluation. The results of tests were compared with the data obtained after injection of normal saline. Macroscopically, there were no changes in the limits of articular capsule and cartilage; there was only slight and enlargement of synovial membrane in the first 7 days after PVP injection. In histological tests it was observed that reaction in the knee joint after PVP injection was characterised it single inflammatory chains without essential participation of neutrophils observed only in synovial membrane and limited to places were tested preparation was seen. Microgel PVP was present in diverticula of synovial membrane to 30th day after injection.

[Investigation of tissue reaction of apatite cement implants impregnated with vancomycin]. / Badanie odczynu tkankowego na wszczepy cementu apatytowego zawierajacego wankomycyne.

Investigation of biocompatibility degree of apatite cement as a carrier of antibiotic--vancomycin was the purpose of the experimental study. Investigation of local reactions of muscular tissue was carried out on 18 rats of Wistar type, by implanting samples of apatite cement with vancomycin in the dorsal muscles. Sections of the animals and microscopic investigations were made 7, 14, 30, 90, 180 and 270 days after the implantation. Investigation of local reactions of bone tissue were carried out on 12 rabbits of New Zealand breed, by implanting the investigated samples into the femoral bone in the region of trochanter. Macroscopic, radiological and microscopic investigations were carried out 1, 3, 6 and 9 months after the surgery. The obtained results of the investigations from muscular and bone tissue, were compared to the investigations in analogical tissues of apatite cement without the medication. In macro- and microscopic investigations in the early period inflammatory reaction of muscles was noticed to be stronger around the samples with vancomycin, in comparison to the control implant. In the later period there was no inflammatory reaction and a thin fibrous connective tissue surrounded the implant and a histological picture was similar, as in cases of an implant without the antibiotic. The local reaction of bone tissue both in the control and in the investigated group (apatite cement with vancomycin) was similar. In the early period the proliferation of rich cellular connective tissue, was noticed. In the later period starting from the 3rd month, formation of young bone tissue was noticed and only locally there were focuses of fibrous tissue. The process observed after splitting of the tested materials into bone tissue, was very similar to healing processes after long bone fraction. The carried out investigations showed, that tissue reaction after implantation of apatite cement and its composite with vancomycin, was very similar and showed a high degree of tissue biocompatibility.

[Comparative evaluation of TNF-alpha induction in vitro and in local tissue reaction after implantation of HAP/TCP and HAP]. / Badania porównawcze indukcji TNF-alpha in vitro i miejscowej reakcji tkanek po implantacji HAP/TCP i HAP.

The aim of this work was the evaluation of biocompatibility and bioactivity of HAP/TCP as compared to HAP. This evaluation was carried out by the in vitro assessment of the induction of TNF-alpha in the rat blood after the contact with the tested HAP. The anther target was to investigate of local muscle tissue reaction of rats bones reaction of rabbits, after the implantation of tested materials. The level of TNF-alpha was estimated by biological method in the supernatants of rat blood cell cultures stimulated in vitro by tested materials. The implantation assessment was carried out on 25 rats and 15 rabbits. The muscle tissue reaction was evaluated after 2, 4, 8, 12, and 24 weeks, while the reaction of bones after 4, 12, and 26 weeks since the implantation. The level of TNF-alpha in the blood after stimulation in vitro with HAP/TCP was on the same level as control group. The implantation of HAP the level of TNF-alpha was twice as high as compared to HAP/TCP and control groups. These differences were of statically importance. The muscle tissue reaction after implantation of HAP/TCP was characterized by moderate inflammation during the early period which lead to the formation of two layer connective tissue capsule. In the capsule wall there were great cells of foreign body type and macrophages. In the cytoplasm of some the cells particles of HAP were noted, what could be regarded as the proof of its resorption. In the bone tissue surrounded HAP/TCP implants the stronger osteoconductive proprieties were observed as compared to the tissue around HAP.

In vitro studies of the influence polyester materials with a different degree of surface wettability have on blood haematological parameters and coagulation and fibrinolysis system parameters.

The paper presents the studies of the influence polyester knitings with a different degree of surface wettability have on the coagulation system, fibrinolytic system and blood haematological parameters in in vitro studies. The studies of Human whole blood were performed for 5, 15, 30, 60, 90, 180 and 240 min. In view of the obtained results in has been reported that a hydrophobic surface knitting does not cause important quantitative changes in any of the selected parametes of the coagulation system and fibrinolysis system. A hydrophilic surface polyester knit causes important lengthening of aPTT value and reduced factor XII, IX and VIII activity. A hydrophilic surface polyester knitting causes a bigger decrease in leukocytes and blood platelets and a bigger increase in beta thromboglobulin in relation to the hydrophobic surface knitting. Neither hydrophobic surface knit nor hydrophilic surface knitting cause changes in the erythrocyte system.

Intraoperative studies and studies on selected parameters of coagulation and fibrinolysis following implantation of DALLON H prostheses with greater surface wettability.

TRICOMED S.A. (Poland) has modified its own knitted polyester vascular prosthesis by change in its physical and chemical characteristics and using hydrophilia. The work has aimed at evaluation of intraoperative tightness and evaluation of change in the number of selected parameters of coagulation and fibrinolysis following implantation of a hydrophilic vascular graft into the thoracic aorta defect in piglets. In view of the experimental tests performed it has been noticed that use of DALLON H prosthesis is easy and the handling of the graft is the same as that of other knitted vascular grafts. DALLON H prosthesis does not need preclotting and it reaches immediate tightness after the blood flow has been restored. In view of the results of the blood studies after implantation coagulation activation in endogenous and exogenous system (aPTT and PT), and increase in activity of factor XII and VII. Concentration of fibrinogen was at a higher level. Thrombin III activation remained at the same level after a primary increase, but protein C activation was decreased. Plasminogen activation was higher which means that the fibrinolytic system was activated. Changes in the level of evaluated indicators were observed until day 14 after implantation of the prosthesis. On day 21st the values of the selected parameters were equal with the values prior to implantation.