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.

Local Effects of a 1940 nm Thulium-Doped Fiber Laser and a 1470 nm Diode Laser on the Pulmonary Parenchyma: An Experimental Study in a Pig Model.

The lungs are a common site of metastases from malignant tumors. Their removal with a minimal but safe tissue margin is essential for the long-term survival of patients. The aim of this study was to evaluate the usefulness of a 1940 nm thulium-doped fiber laser (TDFL) and a 1470 nm diode laser (DL) in a pig model of lung surgery that involved the incision and excision of lung tissue. Histopathological analysis was performed on days 0 and 7 after surgery. Neither TDFL nor DL caused significant perioperative or postoperative bleeding. Histological analysis revealed the presence of carbonized necrotic tissue, mixed fibrin-cellular exudate in the superficial zone of thermal damage and bands of deeper thermal changes. The mean total width of thermal damage on day 0 was 499.46 ± 61.44 and 937.39 ± 109.65 µm for TDFL and DL, respectively. On day 7, cell activation and repair processes were visible. The total width of thermal damage was 2615.74 ± 487.17 µm for TDFL vs. 6500.34 ±1118.02 µm for DL. The superficial zone of thermal damage was narrower for TDFL on both days 0 and 7. The results confirm the effectiveness of both types of laser in cutting and providing hemostasis in the lungs. TDFL caused less thermal damage to the lung parenchyma than DL.

Usefulness of Thulium-Doped Fiber Laser and Diode Laser in Zero Ischemia Kidney Surgery-Comparative Study in Pig Model.

BACKGROUND: The aim of this study was to evaluate the usefulness of a thulium-doped fiber laser and a diode laser in zero ischemia kidney surgery, by carrying out a comparative study in a pig model. MATERIAL AND METHODS: Research was carried out on 12 pigs weighing 30 kg each. A thulium-doped fiber laser (TDFL) and a diode laser (DL) operating at wavelengths of 1940 and 1470 nm, respectively, were used. The cut sites were assessed both macroscopically and microscopically. The zone of thermal damage visible in the histopathological preparations was divided into superficial and total areas. RESULTS: During partial nephrectomy, moderate to minimal bleeding was observed, which did not require additional hemostatic measures. All animals survived the procedure. On day 0, the total thermal damage depth was 837.8 µm for the TDFL and 1175.0 µm for the DL. On day 7, the depths were 1556.2 and 2301.7 µm, respectively. On day 14, the overall thermal damage depth for the DL was the greatest (6800 µm). The width of the superficial zone was significantly reduced on days 7 and 14 after TDFL application. CONCLUSION: Both lasers are suitable for partial wedge nephrectomy without ischemia in pigs. The TDFL produced similar or better hemostasis than the DL, with a smaller zone of thermal damage and, therefore, seems more suitable for application in human medicine.

Comparison of A 1940 nm Thulium-Doped Fiber Laser and A 1470 nm Diode Laser for Cutting Efficacy and Hemostasis in A Pig Model of Spleen Surgery.

Partial and total splenectomies are associated with a high risk of substantial blood loss. Lasers operating at wavelengths strongly absorbed by water have the potential to improve hemostasis and cut while providing a narrow zone of thermal damage. The aim of this study is to compare a thulium-doped fiber laser (TDFL) emitting a wavelength of 1940 nm and a diode laser (DL) operating at 1470 nm for spleen surgery in a pig model. A partial splenectomy and spleen incisions were made in 12 animals using the two laser devices. The hemostasis was evaluated visually during surgeries. Post-mortem and histopathological evaluations were done on days 0, 7, and 14 following surgery. Neither TDFL nor DL caused bleeding on day 0 or delayed bleeding. On day 14, pale streaks at the site of incision were slightly wider after cutting with DL than with TDFL. Histological analysis revealed a carbonized zone with exudation and a deeper zone of thermal tissue damage on day 0. The width of the thermal changes was 655.26 ± 107.70 µm for TDFL and 1413.37 ± 111.85 µm for DL. On day 7, a proliferation of fibroblasts and splenocytes was visible, as well as a formation of multinucleated giant cells adjacent to the residues of carbonization. The zone of thermal damage was broader for DL (1157.5 ± 262.77 µm) than for TDFL (682.22 ± 116.58 µm). On day 14, cutting sites were filled with connective and granulation tissues with the residues of carbonization. The zone of thermal damage was narrower for TDFL (761.65 ± 34.3 µm) than for DL (1609.82 ± 202.22 µm). Thus, both lasers are efficient in spleen surgery, providing good hemostasis. However, TDFL produces a narrower zone of thermal damage, which suggests its better efficiency for spleen surgery, especially when performing more precise procedures.

Assessment of cytotoxic and antimicrobial activity of selected gingival haemostatic agents - in vitro study.

PURPOSE: The present research aimed to determine whether and how the aluminium chloride - based materials affect the cell line of the bacterial line and fungi. METHODS: Cytotoxicity of haemostatic astringents: Alustat (liquid), Alustat (gel), Alustat (foam), Alustin, Hemostat, Racestyptine and Traxodent containing AlCl3 was conducted on L929 cell line with the use of MTT and SRB assays. The antimicrobial activity (CFU and MIC) against C. albicans, S. mutans, L. rhamnosus was determined. RESULTS: In the MTT results, cell viability for all agents were very low. In SRB, the lowest cytotoxicity was demonstrated for Hemostat and Alustat (foam), Traxodent and Racestyptine. Total reduction of the CFU of S. mutans was observed. Alustat (gel) and Alustat (liquid) completely inhibited the growth of C. albicans, S. mutans and L. rhamnosus. CONCLUSIONS: The viability of L929 cells obtained in the SRB assay is more reliable than that obtained in the MTT assay, in the case of gingival haemostatic agents.

Influence of Porous Dressings Based on Butyric-Acetic Chitin Co-Polymer on Biological Processes In Vitro and In Vivo.

In spite of intensively conducted research allowing for the development of more and more advanced wound dressing materials, there is still a need for dressings that stimulate not only reparative and regenerative processes, but also have a positive effect on infected and/or difficult-to-heal wounds. Porous dressing materials based on butyric-acetic chitin co-polyester containing 90% of butyryl and 10% of acetyl groups (BAC 90/10) can also be included in the group mentioned above. Two types of dressings were obtained by the salt leaching method, i.e. a porous sponge Medisorb R and Medisorb Ag with an antibacterial additive. The aim of the study was to evaluate biological effects of porous Medisorb R and Medisorb Ag dressings under in vitro and in vivo conditions. In an in vitro biodegradation test, no mass loss of Medisorb R dressing was observed within 14 days of incubation in physiological fluids at 37 °C. However, on the basis of the FTIR (Fourier Transform Infrared Spectroscopy) tests, surface degradation of Medisorb R dressing was observed. Additionally, the antibacterial activity of the porous Medisorb Ag dressing containing microsilver as an antibacterial additive was confirmed. The in vivo studies included inflammatory activity, skin irritation and sensitisation tests, as well an assessment of local effect after contact with subcutaneous tissue up to 6 months and skin wounds up to 21 days. In the in vivo tests, the dressings exhibited neither effects of skin irritation nor sensitisation. Under macroscopic examination, in full thickness defects of subcutaneous tissue and skin, the dressings caused wound healing with no inflammation, undergoing the most gradual biodegradation between weeks 4 and 8, and the observed differences were statistically significant. In the histological assessment, a weakened, limited inflammatory process associated with degradation of the material has been observed. The process of skin wound healing under Medisorb R dressing in the early period was accelerated compared to that observed in the control group with a gauze dressing.

Preliminary Evaluation of Thulium Doped Fiber Laser in Pig Model of Liver Surgery.

Partial liver resection is a treatment of choice for liver tumors; the range of parenchyma excision varies from a small part of the tissue surrounding the neoplasm up to 70% of the organ. One of the major concerns during liver resection is blood loss. Thulium lasers which are characterized by the length of emission wave corresponding to a peak absorption of water create a new possibility of cutting tissues efficiently with minimal thermal damage and concurrently providing a good hemostasis control. The aim of our study was to evaluate an impact of liver transection with thulium doped fiber laser on an intraoperative bleeding and histopathological changes during postoperative period in swine model. Ten animals were subjected to open surgery partial liver resection and an incision of liver tissue with an all-fiber, diode-pumped, and continuous-wave Tm3+-doped fiber laser emitting 37.4 W of output power at ~1.94 µm wavelength. The macroscopic and histopathological evaluation was performed intraoperatively as well as 7 and 14 days after surgery. Macroscopically almost no bleeding was observed during surgery and no signs of bleeding were stated after 7 and 14 days. Histopathological analysis of the transection margin revealed a thermal damage area ranging in depth from 620.23 ± 23.82 µm on the day of surgery to 1817.70 ± 211.98 µm after 7 days. In the samples taken intraoperatively and after 7 days a superficial zone of carbonization was visibly separated from the deeper changes. After 14 days one 765.35 µm deep zone characterized by a granulation was present. In conclusion, thulium doped fiber laser is efficacious in cutting with a narrow zone of thermal injury and provides a good hemostasis during liver transection, thus being a potential tool for oncotic liver surgery.

Influence of surface modifications of a nanostructured implant on osseointegration capacity - preliminary in vivo study.

In response to the need for implant materials characterized by high biocompatibility a new type of nanostructured Ti6Al7Nb implants for osseous tissue regeneration have been fabricated. The nanostructured cylindrical implants were manufactured in accordance with 3D CAD data using the Selective Laser Melting (SLM) method. Implants were subjected to chemical polishing using a mixture of nitric acid and fluoride (test group) as well as cleaned in distilled water and isopropyl alcohol (control group). The structural and morphological properties of the obtained samples were determined by using XRD (X-ray powder diffraction), TEM (transmission electron microscopy) and SEM (scanning electron microscopy) techniques. The particle size was verified and calculated by Rietveld method to be in the range of 25-90 nm. In the present study, experimental in vivo tests concerning implants fabricated from a nanostructured Ti6Al7Nb alloy, which may substitute bone tissue, were discussed in detail. The control group and test group were used in the study. The animal model was New Zealand rabbit. The implants were implanted into skull fornix and observed after 1, 2 and 3 months. The results of macroscopic and microscopic analysis proved better osseointegration of chemically modified implants.

Biological Properties of Low-Toxicity PLGA and PLGA/PHB Fibrous Nanocomposite Implants for Osseous Tissue Regeneration. Part I: Evaluation of Potential Biotoxicity.

In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(l-lactide-co-glycolide) (PLGA) and syntheticpoly([R,S]-3-hydroxybutyrate), PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and l-lactide (PLGA) was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc)4 as an initiator. The prototypes of the implants are composed of three layers of PLGA or PLGA/PHB, nonwoven fabrics with a pore structure designed to provide the best conditions for the cell proliferation. The bioactivity of the proposed implants has been imparted by introducing a hydroxyapatite material and IGF1, a growth factor. The developed prototypes of implants have been subjected to a set of in vitro and in vivobiocompatibility tests: in vitro cytotoxic effect, in vitro genotoxicity and systemic toxicity. Rabbitsshowed no signs of negative reactionafter implantation of the experimental implant prototypes.

Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity.

Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide), (PLGA), and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate) (PLGA/PHB). The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

On influence of anodic oxidation on thrombogenicity and bioactivity of the Ti-13Nb-13Zr alloy.

PURPOSE: This paper reports on the results of investigations on the blood response to the modified of surfaces titanium alloys. METHODS: To enhance biocompatibility of the Ti-13Nb-13Zr alloy, anodisation was performed at 80 and 150 V. The oxidation process was carried out in a solution containing 4 mol dm-3 H3PO4 and 0.59 mol dm-3 Ca(H2PO2)2. RESULTS: The haemolytic activity of the titanium alloy surface was not altered much by the anodisation. The obtained values of the percentage of haemolysis were well below the levels required for the materials intended for blood contact. The clotting time of the blood was similar for the as-ground sample and the sample anodised at 80 V. For the sample anodised at 150 V the clotting time was shorter. The differences between these samples were observed in partial thromboplastin time after activation, prothrombin time and thrombin time, after 24 h. Extracts taken from the samples were not toxic towards the L-929 mouse fibroblast cells. CONCLUSIONS: The proposed treatment might be appropriate for the preparation of modified Ti-13Nb-13Zr surfaces intended for bone reconstruction or cardiovascular implants depending on process parameters.

Histological Evaluation of the Local Soft Tissue Reaction After Implanting Resorbable and Non-resorbable Monofilament Fibers.

BACKGROUND: The development of technologies and scientific disciplines connected with medical implantation devices is dynamically affecting modern treatments by contemporary medicine and veterinary medicine; it also entails a need to monitor their impact on living organisms. OBJECTIVES: The aim of the study was to conduct a comparative histological evaluation of the response of soft tissues after implanting monofilament fibers from resorbable glyconate and from non-resorbable polypropylene (PP) and polyamide (PA) in rats. MATERIAL AND METHODS: Non-resorbable polyamide-based fibers were applied to skin anastomoses in rats. Macroscopic and histological evaluations were performed on the 7th, 14th and 30th days. Non-resorbable polypropylene fibers and resorbable glyconate fibers (composed of 72% glycolide, 14% trimethylene carbonate and 4% caprolactone) were implanted in muscle tissue for periods of 7, 14, 30 and 90 days. RESULTS: A semi-quantitative and qualitative histological evaluation found different dynamics and degrees of intensification of cell and tissue response around the resorbable and non-resorbable fibers being tested. The resorption process of the glyconate threads caused a prolonged inflammatory cellular response compared to the non-resorbable threads; it passed, however, without the participation of giant cells. Around the non-resorbable threads the observed cellular response was less intensified, with the formation of single polymorphonuclear macrophages around the PP threads, along with a stronger degree of fibrosis and the presence of fatty infiltrate. CONCLUSIONS: During the early period, moderately intensified inflammatory cell response with the presence of single giant cells was observed around the non-degradable PA and PP fibers. In the late period, a band of fibrous connective tissue was present around the PP threads. Glyconate fibers underwent fragmentation and the process of resorption, which was associated with a weakly intensified inflammatory process lasting up to 90 days after implantation.

[Examination of influence of microstructure of grafts on TiO2 base on the process of bone tissue forming]. / Badanie wplywu mikrostruktury wszczepów na osnowie TiO2 na proces formowania sie tkanki kostnej.

AIM OF THE STUDY: Evaluation of the influence of the introduced structure modification in porous ceramic grafts on TiO2 base on overgrowing with bone tissue, in examinations with use of scanning microscopy and X-rays was the subject of the examinations. MATERIAL AND METHOD: New ceramic materials based on TiO2 with high values of mechanical resistance, large sintering degree and biocompatibility in in vitro conditions were prepared. Those properties cause that they are worth interest as potential osteosubstitutive materials. Two kinds of grafts were created from ceramics based on TiO2: with compact and porous structure. The introduced structure modification - macroporosity - had the purpose to give osteoconductive properties to the grafts, to evoke processes favorable for bone tissue forming. In examinations of the local reaction of bone tissue after implantation of the formed porous grafts, degree of their osteointegration, the essential issue is the evaluation of the settling of the inner spaces with supporting tissues. Samples of the tested compact and porous materials in the form of cylinders were implanted in femoral bones of rabbits for a period till 6 months. The surfaces of grafts and the degree of their settling with supporting tissues were evaluated in cross-sections of the implants with light and scanning microscopic methods and they were confirmed in X-ray tests. RESULTS: Analysis of the obtained data showed that, the surface of solid ceramic on TiO2 base was covered mainly with increasing with a time of observation quantities of extracellular substance and lamellas of bone. The macrporous structure of porous ceramic on TiO2 base enabled settling of the inner spaces of graft with supporting tissue cells, partly in the 1st month, more intensively in the 3rd and it was not completed in the 6th month after implantation. CONCLUSIONS: Porous grafts in the form of ceramic foam on TiO2 base showed osteoconductive properties, though process of colonization after 6th month observation was not completed and the condition of the cells inside of the implant was reduced.

[Influence of the gelatin-alginate matrixes with calcium lactate in plasma coagulation system after implantation in soft tissues]. / Wplyw matryc zelatynowo-alginianowych z mleczanem wapnia na osoczowy uklad krzepniecia po implantacji w tkanki miekkie.

BACKGROUND: Bioresorbable porous substrates from copolymers have their application in tissue engineering to culture tissues in vitro. The advantage of polymers is the production of thermoplastic elements and their ability to biodegrade in a living body. Gelatin, collagen, alginates are part of dressings used for topical administration of the drug. Research was undertaken to achieve a porous gelatin-alginate matrix which could be used in therapy as among others, a carrier for a drug. OBJECTIVES: Evaluation of the impact of modified gelatin-alginate matrix on activation of plasma coagulation in vivo. MATERIAL AND METHODS: Gelatin-alginate matrix cross-linked with calcium ions was implanted in the muscle tissue of a rat. The control group constituted animals not implanted with material, but they passed the operating procedure. Blood samples of plasma coagulation test and control group were collected after 1, 2, 3, 5, 7, 10, 14 days of the procedure. RESULTS: Prolongation of APTT and shortening of PT and TT with the unchanged values of fibrinogen and the count of platelet cells was observed till the 5th day on the basis of the obtained results. Prolongation of APTT with the unchanged values of the remaining parameters of the coagulation system was observed after 7, 10 and 14 days with unchanged values of PT and TT coagulation. CONCLUSIONS: The matrix gelatin-alginate with calcium ions in the biological environment undergoes biodegradation in soft tissues. This process in the initial period influences the activation of the coagulation within the intrinsic and extrinsic system. From the 5th to 14th day the activation of coagulation was observed only in the intrinsic system.

Evaluation of healing processes of intraosseous defects with and without guided bone regeneration and platelet rich plasma. An animal study.

BACKGROUND: In most cases, the natural healing of intrabony defects only leads to restoration of tissue continuity without differentiation and function. However, repair is not regarded to be an optimal treatment method, as confirmed in many clinical cases. Thus it is important to choose a surgical procedure which makes it possible to achieve restitution ad integrum of the bone structure. The choice of the GBR technique is crucial, in terms of the clinical conditions and limitations resulting from the use of a particular material. OBJECTIVE: The objective of this study has been the analysis of effectiveness of selected surgical treatment techniques of intrabony defects in rabbits. MATERIALS AND METHODS: Research was conducted on 36 white rabbits. The operation technique was a criterion of division into 3 groups: BG/BOC (Bio-Oss Collagen(®)+Bio-Gide Perio(®)), BOC/PRP (Bio-Oss Collagen(®)+PRP), C (control group). Qualitative and quantitative histopathological evaluation was carried out after 1, 3, 6 and 12 months. RESULTS: The highest value of the bone surface area 31.9% (SD 1.8) was achieved in BOC/BG group three months after the implantation, while the lowest was revealed in C - group - 12.5% (SD 1.32) one month following the procedure. CONCLUSIONS: Upon quantitative histological assessment, the bone tissue presented the most intensive osteogenesis within one month from the application of BOC/PRP, whereas this was observed after the application of BOC/BG in later stages. The application of two regenerative methods influenced the rate, quality and overall treatment of intraosseus defects.

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.

Early histological evaluation of bone defect healing with and without guided bone regeneration techniques: experimental animal studies.

INTRODUCTIONS: To obtain osseous tissue regeneration, treatment methods referred to as guided bone regeneration are used which utilize the mechanical, chemical, and biological properties of materials. MATERIAL/METHODS: Eighteen white rabbits were used. Under general anesthesia, a 5 mm in diameter defect was created transcutaneously in the femur trochanter major. The rabbits were divided into three groups depending on the type of the intraosseous defect (ID) treatment: in group I (C) the control IDs were left to heal spontaneously, in II (BOC+BG) the IDs were filled with Bio-Oss Collagen and Bio Gide Perio membrane, and in III (PRP) the IDs were filled with BOC and platelet-rich plasma (Curasan Centrifuge). The animals were sacrificed 1 and 3 months after the surgical procedure. The histological material was stained with hematoxylin and eosin and using the van Gieson method. RESULTS AND CONCLUSIONS: In the earlier histological examinations (1 and 3 months after the procedures), resorption of the biomaterial and the formation of new bone trabeculas were observed in both groups II and III. At the first observation the extent of biomaterial resorption and the intensity of the osteogenic process were greater in group III, but after 3 months group II had a slight advantage. Fragmented remnants of the biomaterial in both groups were surrounded by newly formed bone and locally by fibrous connective tissue. At both observation times the number of bone trabeculas after implantation in groups II and III was greater than in the control group.

[Activation of nuclear factor kappaB (NF-kappaB), induction of proinflammatory cytokines in vitro and evaluation of biocompatibility of the carbonate ceramic in vivo]. / Aktywacja jadrowego czynnika transkrypcyjnego NF-kappaB, indukcja cytokin prozapalnych in vitro oraz badania biozgodnosci ceramiki weglanowej in vivo.

UNLABELLED: Ceramic materials based on calcium carbonate have been prepared in response for the demand for resorbable materials for use in bone surgery. Calcium carbonate in the form of crystalline aragonite or calcite with various amount of lithium fluoride was the raw material. Material CC-1FA from crystalline aragonite (99% CaCO3 and 1% LiF), CC-5FA - from crystalline aragonite (95% CaCO3 and 5% LiF) and CC-1FK -material from crystalline calcite (99% CaCO3 and 1% LiF) was studied. To evaluate their biocompatibility and inflammatory effect we investigated the activity of nuclear factor kappaB (NF-kappaB) and proinflammatory cytokine concentrations: tumor necrosis factor TNF-alpha, interleukins 11-6 and IL-8 in peripheral human leukocytes (PBL) after stimulation in vitro with tested calcite materials. Evaluation of local soft tissue reaction after implantation was also the aim of our study. Proinflammatory cytokines take part in inflammatory reaction caused by biomaterials. Expression of these proteins is controlled by proinflammatory regulatory transcription factors including the commonly appearing NF-kappaB (Nuclear Factor kappaB). In a quiescent cell NF-kappaB resides in the cytosol in an inactive form which its activated under the influence of kinases. The activated NF-kappaB protein translocates from cytosol to nucleus of cell and binding to specific DNA sequence it initiates transcriptions. Thanks to the quick regulation of immunological response it ensures the survival of cells in unfavorable reactions of environmental factors. It regulates the expression of many genes mainly connected with the course of the inflammatory process (of some cytokines, proteins of acute phase, collagenasis, stromilozine other enzymes decomposing the elements of matrix) and with proliferation and differentiating of cells. However its excessive activity can lead to unfavorable reactions, for example uncontrollable division of cells, appearance of giant cells of foreign body type. In our study protein expression of NF-kappaB in PBL were assessed using anti-c-Rel-antibody (PBL expressing c-Rel in the nucleus = labelled NF-kappaB (+) cells). The NF-kappaB activation in PBL was expressed as: the percentage of NF-kappaB (+) cells. The level of cytokines: IL-6, IL-8 and TNF-alpha level in the supernatants from leukocytes culture with tested materials was determined by an enzyme-linked immunoabsorbent assay (ELISA) after 24 and 72 hours incubation. The local tissue reaction in vivo was evaluated 1 and 3 months after implantation calcite devices into dorsal muscles of rats. The achieved results showed that the tested calcite material incubated 24 and 72 hours with PBL culture didn't synthesized higher amounts of the cytokines IL-6 and IL-8 in comparison with the untreated cells. All tested materials stimulated after 24 and 72 hours PBL culture to produce a significant level of TNF-alpha (p < 0.05) (higher level after CC-5FA and CC-1FA materials and lower after CC-1FK). Activation of transcription factor nuclear factor NF-kappaB in leukocytes after 24 hours incubation with CC-5FA, CC-1FA was higher than CC-1FK but significantly was only after CC-5FA stimulating. The expression of NF-kappaB after 72 hours of incubation decreased and was on the level comparable with control group. Histological observation 1 month after implantation showed that the carbonate ceramic devices were surrounded with connective tissue surrounding implants capsule with presence of macrophages. Additionally after 3 month in the dense connective tissue cartilaginous and calcification focus was visible. Soft tissue reaction showed chronic inflammatory reaction connected with resorbtion of biomaterials, the most increased after implantation of CC-5FA, than CC-1FA and CC-1FK. CONCLUSION: Transcription nuclear factor NF-kappaB was activated after in vitro stimulation in short time by the tested calcite material CC-5FA. This activity was correlated with induction in vitro of TNF-alpha in short and long time. The most increased soft tissue reaction 1 and 3 month after implantation of CC-5FA material was found. Our study showed that calcite materials can activate NF-kappaB and demonstrated differences in biocompatibility of tested materials.

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.

[The effect of polyester vascular prostheses on synthesis TNF-alpha, IFN-gamma and NO by human peripheral blood leukocytes--in vitro]. / Wplyw poliestrowych protez naczyniowych na synteze TNF-alpha, IFN-gamma oraz NO przez ludzkie leukocyty krwi obwodowej--in vitro.

Vascular prostheses produced on the basis of polyester are today commonly used in vascular surgery. To improve their biofuncionality special technologies are used, among them double knit and hydrophile feature enrichment. These modifications could cause the local activation of leukocytes to produce the mediators of inflammatory reaction, which in turn leads to hyperplasia of endothelium and other dangerous complications. In our study we used two kinds of polyester prostheses: double velour knitted hydrophilic Dallon H and standard double velour knitted prosthesis Dallon as control. The aim of this work was to compare in vitro the levels of cytokines TNF-alpha, interferon (IFN) and nitric oxide (NO) found in the supernatants of human blood leukocyte cultures after stimulation by both these above-mentioned vascular prostheses materials which are designed for use in direct blood contact. Tested implant materials Dallon H had no influence on synthesis of production of IFN, TNF-alpha and NO by human blood leukocytes. These results allow to made the initial selection of biomaterials before their in vivo evaluation.