Upgrading Pyrolytic Residue from End-of-Life Tires to Efficient Heterogeneous Catalysts for the Conversion of Glycerol to Acetins.

Recovered carbon blacks (rCBs) produced from end-of-life tires using pyrolysis were transformed into solid acid catalysts for the synthesis of acetins, i.e., products with a wide spectrum of practical applications. Tuning the chemical properties of the surface of samples and introducing specific functional groups on the rCBs were achieved through carbon functionalization with concentrated H2SO4. The initial and modified rCBs were thoroughly characterized using techniques such as elemental analysis, potentiometric back titration, thermogravimetric technique, scanning and transmission microscopy, X-ray photoelectron spectroscopy, etc. The catalytic activities of the samples were measured via batch mode glycerol acetylation performed at 110 °C and compared to the catalytic performance of the functionalized commercial carbon black. The modified rCBs were found to show a significant catalytic effect in the tested reaction, giving high glycerol conversions (above 95%) and satisfactory combined yields of diacetins and triacetin (~72%) within 4 h; this behavior was attributed to the presence of -SO3H moieties on the surface of functionalized rCBs. The reusability tests indicated that the modified samples were catalytically stable in subsequent acetylation runs. The obtained results evidenced the feasibility of using end-of-life tires for the production of effective acid catalysts for glycerol valorization processes.

Studies of New Iridium Catalysts Supported on Modified Silicalite-1-Their Structure and Hydrogenating Properties.

This paper investigates the catalytic properties of the iridium catalysts supported on modified silicalite-1. Post-synthesis modification of silicalite-1, with solutions of ammonium compounds (NH4F and NH4OH), appeared to be an efficient method to generate the acidic sites in starting support. The modification of support led not only to changes in its acidity but also its porosity-formation of additional micro- and mesopores. The novel materials were used as supports for iridium. The iridium catalysts (1 wt.% Ir) were characterized by N2 adsorption/desorption measurements, temperature-programmed reduction with hydrogen (TPR-H2), H2 chemisorption, transmission electron microscopy (TEM), temperature-programmed desorption of ammonia (TPD-NH3), X-ray photoelectron spectroscopy (XPS) and tested in the hydrogenation of toluene reaction. The catalytic activity of iridium supported on silicalite-1 treated with NH4OH (higher porosity of support, better dispersion of active phase) was much higher than that of Ir supported on unmodified and modified with NH4F silicalite-1.

Recent magmatism drives hydrocarbon generation in north-east Java, Indonesia.

Conventional studies of petroleum basins associate oil generation with the gradual burial of organic-rich sediments. These classical models rely on the interplay between pressure, temperature, and the time required for organic matter transformation to oil and gas. These processes usually occur over geological timescales, but may be accelerated by rapid reactions when carbon-rich sediments are exposed to migrating magmatic fluids. The spectacular Lusi eruption (north-east Java, Indonesia) is the surface expression of the present-day deep interaction between volcanic and sedimentary domains. Here we report the ongoing generation of large amounts of hydrocarbons induced by a recent magmatic intrusion from the neighbouring Arjuno-Welirang volcanic complex. We have investigated a unique suite of oil and clast samples, and developed a detailed conceptual model for the complex hydrocarbon migration history in this part of the basin by integrating multidisciplinary techniques. Our results show that palynology, organic petrology, and chlorite microthermometry are the most sensitive geothermometers for basins affected by recent magmatic activity. These findings further our understanding of the driving mechanisms fueling the world's largest active mud eruption and provide a unique dataset to investigate modern hydrocarbon generation processes.

The design, synthesis and catalytic performance of vanadium-incorporated mesoporous silica with 3D mesoporous structure for propene epoxidation.

V-containing mesoporous silica with 3D structure was prepared by a hydrothermal procedure using NH4VO3 as the vanadium precursor and with varied reaction mixture pH values (pH = 3 and pH = 5). The combined use of DR UV-vis and H2-TPR techniques confirmed the successful incorporation of vanadium into the structure of the mesoporous silica material. The number of acid sites, evidenced by ammonia TPD, strongly correlates with the vanadium content. Propene oxidation with N2O revealed the noticeable activity of the synthesised vanadium-containing mesoporous materials in epoxidation reactions. The activity of the synthesized vanadosilicates is compared with the performance of vanadium-supported catalysts (on mesoporous silica of 3D structures) prepared by wet-impregnation method. On the basis of TOF analysis indicating the activity of particular vanadium ions, it was evidenced that although the presence of isolated V species is crucial in propene epoxidation, the availability of the active species is of paramount importance for proper vanadium utilization.

The role of laser biostimulation in early post-surgery rehabilitation and its effect on wound healing.

BACKGROUND: The aim of this paper is to investigate whether laser biostimulation starting on the first day after surgery of the brachial plexus or peripheral nerves has a positive therapeutic effect on wound healing. MATERIAL AND METHODS: Surgical procedures were carried out on 44 male Wistar rats. The animals were divided into a control group (Group 1), where the surgical wounds were allowed to heal spontaneously, and an experimental Group 2, where the wounds were exposed to laser irradiation with the following parameters: wavelength 810 nm, power 100 mW, energy 15 J, laser exposure surface 3 cm(2), single application time 2 min. 30 sec., continuous mode. The results were assessed with pathomorphological tests (gross appearance of the wound, light and electron microscopy studies) and breaking strength examination. Statistical analysis used arithmetic means, standard deviations and Student's t test for independent samples. RESULTS: Low energy infrared laser radiation had a beneficial effect on the covering of the scar with stratified squamous cornifying epithelium and intensified wound healing. CONCLUSIONS: The gross and microscopic findings indicated a beneficial effect of laser stimulation on wound healing. These results underscore the utility of biostimulation lasers in the early post-operative period. Physicomechanical investigations did not reveal an effect of infrared laser biostimulation on the breaking strength of the cutaneous scar.

[Evaluation of nonabsorbable surgical sutures in tubal anastomoses with use of microsurgical techniques. An experimental study]. / Ocena nici polipropylenowych w zespoleniach jajowodowych z zastosowaniem technik mikrochirurgicznych. Badania eksperymentalne.

In the paper there have been evaluated synthetic nonabsorbable surgical sutures--PROLENE. The valuation concerned their usefulness to carrying out the operations of oviducts with use of microsurgical technique. It consisted in determination of biocompatibility degree of analyzed sutures within tubal tissues and also their technical utility to this kind of procedures. The valuation of the surgical sutures was performed on the ground of experimental studies with use of laboratory animals--New Zealand white female rabbits, in which end to end microsurgical tubal anastomoses were made, with use of analyzed sutures. In further stage, pathomorphological investigations of the animals were performed (in various time after the operation), during which there were conducted microscopic observations of histologic slides derived from tubal anastomoses regions. The purpose of the work was trying to appoint the most adequate suture material for carrying out the operations of oviducts with use of microsurgical technique. It was also an assistance for an operator to take a decission of choice of the proper surgical sutures for surgical treatment of female mechanical infertility and other kind of microsurgical operations which are performed in gynaecology. Generally good technical utility in microsurgical practice of nonabsorbable surgical sutures--PROLENE was stated. They cause the formation of only single peritoneal adhesions, mainly in the regions of tubal anastomoses previously made and produce relatively small tubal tissue reaction, which testifies to high biocompatibility of the sutures, as the implantation material. The analyzed surgical sutures characterize themselves of very good usefulness to microsurgical operations of oviducts.

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.

[Evaluation of long-time resorption surgical sutures in tubal anastomoses with use of microsurgical techniques. An experimental study]. / Ocena nici chirurgicznych o dlugim okresie resorpcji w zespoleniach jajowodowych z zastosowaniem technik mikrochirurgicznych. Badania eksperymentalne.

In the paper there have been evaluated synthetic absorbable surgical sutures--MAXON, of long time of their resorption in an organism. The valuation concerned their usefulness to carrying out the operations of oviducts with use of microsurgical technique. It consisted in determination of biocompatibility degree of analyzed sutures within tubal tissues and also their technical utility to this kind of procedures. The valuation of the surgical sutures was performed on the ground of experimental studies with use of laboratory animals--New Zealand white female rabbits, in which "end to end" microsurgical tubal anastomoses were made, with use of analyzed sutures. In further stage, pathomorphological investigations of the animals were performed (in various time after the operation), during which there were conducted microscopic observations of histologic slides derived from tubal anastomoses regions. The purpose of the work was trying to appoint the most adequate suture material for carrying out the operations of oviducts with use of microsurgical technique. It was also an assistance for an operator to take a decission of choice of the proper surgical sutures for surgical treatment of female mechanical infertility and other kind of microsurgical operations which are performed in gynaecology. Generally good technical utility in microsurgical practice of surgical sutures MAXON--absorbable of long period of their resorption in tissues was stated. They cause the formation of only single peritoneal adhesions, mainly in the regions of tubal anastomoses previously made and produce relatively small tubal tissue reaction, which testifies to high biocompatibility of the sutures, as the implantation material. The analyzed surgical sutures characterize themselves of very good usefulness to microsurgical operations of oviducts and they seem to be the most adventageous for performing this type of operations. They give a greater certainty of formation of durable accretion of tubal wall in the place of created anastomosis, with simultaneous complete elimination of the implantation material from the organism.

[Evaluation of short-time resorption surgical sutures in tubal anastomoses with use of microsurgical techniques. An experimental study]. / Ocena nici chirurgicznych o krótkim okresie resorpcji w zespoleniach jajowodowych z zastosowaniem technik mikrochirurgicznych. Badania eksperymentalne.

In the paper there have been evaluated synthetic absorbable surgical sutures--Coated VICRYL, of short time of their resorption in an organism. The valuation concened their usefulness to carrying out the operations of oviducts with use of microsurgical technique. It consisted in determination of biocompatibility degree of analyzed sutures within tubal tissues and also their technical utility to this kind of procedures. The valuation of the surgical sutures was performed on the ground of experimental studies with use of laboratory animals--New Zealand white female rabbits, in which "end-to-end" microsurgical tubal anastomoses were made, with use of analyzed sutures. In further stage, pathomorphological investigations of the animals were performed (in various time after the operation), during which there were conducted microscopic observations of histologic slides derived from tubal anastomoses regions. The purpose of the work was trying to appoint the most adequate suture material for carrying out the operations of oviducts with use of microsurgical technique. It was also an assistance for an operator to take a decission of choice of the proper surgical sutures for surgical treatment of female mechanical infertility and other kind of microsurgical operations which are performed in gynaecology. Generally good technical utility in microsurgical practice of surgical sutures Coated VICRYL--absorbable of short period of their resorption in tissues was stated. They cause the formation of only single peritoneal adhesions, mainly in the regions of tubal anastomoses previously made and produce relatively small tubal tissue reaction, which testifies to high biocompatibility of the sutures, as the implantation material. The analyzed surgical sutures characterize themselves of very good usefulness to microsurgical operations of oviducts.

[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.

[Tissue reaction after implantation of ceramic biomaterials with introduced electrokinetic zeta potential on surface]. / Odczyn tkankowy po implantacji biomaterialów ceramicznych z wprowadzonym na powierzchnie potencjalem elektrokinetycznym zeta.

Studies over implants showed, that not only the kind of structure of material, but also the character of surface influences the local reaction. Endeavour to obtain the best possible biological properties of implants, intended to supplementing of osseous decreases, contributed to carrying out investigations over implants about active surface. Electrochemical reactions, occurring on implants surface, lead to beginning of electric occurrences on implant/tissue interface and beginning of so-called potential zeta. Utilization of these properties in implantology, induced us to carry out experimental studies with use of biomaterials with modified surface and of influence of potential zeta on biocompatibility. The carried out studies referred: to comparative investigations of tissue reaction of implants ceramic with of solid and porous surface, and to influence of electric load zeta on tissue reaction. For the studies were used 3 kinds of ceramics: porous, solid and solid ceramics with potential zeta (silanovated). The studies were carried out on 50 rats, to which studied ceramics was implanted into back muscles. Pathomorphological assessments were carried out 1, 4, 12, 26 and 32 weeks after implantation. The results of pathomorphological studies after implantation of ceramics solid and solid silanovated showed, that already after 1 week was formed thin membrane with visible, small blood-vessels. After 32 weeks it was significantly thicker. The produced capsule was strongly connected with surrounding muscles, and from side the implant adhered to it's surface. In case of implants of porous ceramics, already after 1 week the produced capsule of connective tissue was clearly thicker, and after 32 weeks it was, whitish, opaque, strongly connected to surrounding muscles. From side implant it became rooted in pores of ceramics. In microscopic studies it was shown, that both in early and distant period, the character and size of tissue reaction was dependent on structures of implant surface. Porous ceramics implanted in soft tissues, produced stronger inflammatory reaction being characterized with long lasting phase infiltration, which drove to producing thick connective tissue capsule. 32 weeks after implantation in the produced capsule these were visible former focuses of chondroid tissue. Reaction tissue occurring round solid ceramics, was characterized with shorter and less intensive proliferation phase. After 32 weeks visible former thin connective tissue capsule was visible. Ceramics with potential zeta (silanovated) generated minimum-tissue reaction, without visible proliferation phase. Studies in light and scanning microscopes, executed 32 weeks after implantation showed, that in produced thin layer of connective tissue were visible with adamantinating and calcifications focuses, and on the surface of ceramics were formed osseous tin plates.

[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 biocompatibility of the apatite cement]. / Badanie biozgodnosci cementu apatytowego.

The results of experimental studies of biocompatibility of the apatite cement, implanted in the muscular tissue of rats and bone tissue of rabbits were presented in this study. Investigations of the local reactions of the muscular tissue were carried out on 18 rats of Wistar type by implanting samples from the apatite cement in the dorsal muscles. Macroscopic and microscopic investigations were carried out 7, 14, 30, 180, 270 days after the implantation. Investigations of local reactions of bone tissue were carried out on 12 rabbits of New Zealand breed. By implanting the tested material into the femoral bone in the region of trochanter. Sections of the animals were made 1, 3, 6, and 9 months after the surgery. In the early period active inflammatory process was seen in the muscles in the direct vicinity of the implant and then it disappeared leading to formation of a thin fibrous connective tissue capsule. Histological investigations made of bone tissue later showed, formation of young tissue with small focuses of fibrous connective tissue. In the carried out investigations it was shown that the apatite cement is characterized with a high degree of biocompatibility and osteoinductive activity.

[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.

Tissue reaction after implantation of Spongostan, as the carrier of xenogenic bone morphogenetic protein. Experimental study.

Reconstruction or filling of bone defects, especially in the maxillofacial region, often requires use of biomaterials. An implant should fasten healing of the bone gap or it should replace autogenic bone grafts. The combination of bone morphogenetic proteins with suitable carrier may fulfill these requirements. Proteins causing differentiation of mesenchymal cells in chondroblasts and osteoblasts were called Bone Morphogenetic Proteins--BMPs. The authors extracted BMP from bovine bones and placed it into collagen carrier formed from generally accessible hemostatic sponge--Spongostan. The implants were grafted into rat femoral muscle pouches in order to trace the tissue response. Pathologic examinations were performed 3, 6 and 8 weeks after implantation. On the basis on macroscopic and microscopic examinations it was stated that collagen sponge speckled with BMP caused minimal tissue response and evolved characteristic thin connective tissue capsule formation around the implant. The connective tissue penetrated spongious structure of the implant, filling the spaces, which became growing due to sponge resorption. Characteristic hyalinization and sparse chondroblasts were visible 8 weeks after implantation.

Tissue reaction following the implantation of a DALLON H vascular prosthesis in the thoracic aorta defect. Experimental tests.

Vascular prostheses made of polyester or polytetrafluoroethylene fibres are most frequently used nowadays. Woven polyester prostheses are sealed following the suturing in the circulatory system, but they cause a tissue reaction. Knitted polyesters grafts cause a lesser tissue reaction, but demand intraoperative sealing. Thus numerous tests to improve them are conducted. TRICOMED S.A. (Poland) has modified the company's own double velour knitted vascular prosthesis. The graft's physical and chemical features have been changed and hydrophilia has been used, due to which dripping the graft takes little blood and its tightness is achieved in a dozen or so seconds. The evaluation of surgical qualities as well as the healing-in process of the modified knitted hydrophilic prosthesis DALLON H has been conducted at the Department of Experimental Surgery and Biomaterials of Wroclaw Medical University. DALLON H prosthesis was compared to DALLON, a standard double velour knitted prosthesis. The tests were performed on 16 Polish breed piglets with 25-35 kg of weight and 2.5 months of age. Two follow-up periods of 3 and 6 months were established following the surgeries. In each group six piglets had a 6-cm-long segment of DALLON H prosthesis sutured in the thoracic aorta defect, whereas two piglets received a 6-cm-long segment of DALLON prosthesis. The evaluation of surgical qualities of both kinds of grafts was performed intraoperatively. The main emphasis was put on the conditions in which the grafts became tight and the way they were handled during the aortal anastomosis. After 3 and 6 months the animals were autopsied. A macroscopic analysis of the incurred preparations was performed. Roent-genograms of the thoracic aorta sections replaced by the grafts were made in order to establish the shape of their lumen and present calcium salt deposits in their region. Light microscopic tests were performed by dying the preparations with hematoxiline and eosine to differentiate tissues and basic morphotic elements; using the van Giesen method, in order to reveal collagenous fibres; using the Weigert method to reveal elastic fibres, and using the Koess method to reveal calcium salt deposits. An ultrastructural evaluation of the internal surface of the grafted vascular sections was performed by a scanning electron microscope. In view of the experimental tests performed it has been established that DALLON H prosthesis used in vascular surgical procedures is not difficult and the prosthesis can be handled in the same way as some other knitted vascular prostheses. DALLON H does not need preclotting and when the blood flow has been restored through the grafted section the prosthesis immediately becomes completely tight. In view of the tests performed no differences in the healing-in process between the modified DALLON H and DALLON prostheses were observed.