Biomedical subjects

E Cenni

Publications and source records attributed to E Cenni.

At least 19 recordsLinked to original sources

PubMed2007

Interferon-alpha inhibits in vitro osteoclast differentiation and renal cell carcinoma-induced angiogenesis.

Bone is a common site of osteolytic and richly vascularized metastases of renal cell carcinoma (RCC) and Interferon (IFN)-alpha based therapies have been considered for the treatment of patients affected by this disease. The effects of IFN-alpha on metastatic RCC patients have been related to its immunomodulatory, and cytotoxic activity on tumor cells, but there could be an effect also on tumor induced osteoclast differentiation and bone angiogenesis. When osteoclasts obtained from human peripheral blood mononuclear cells, cultured in the presence of receptor activator of nuclear factor-kappaB (RANKL) and macrophage-colony stimulating factor (M-CSF), were treated with IFN-alpha, the expression of bone tartrate resistant acid phosphatase (TRACP) type 5b was reduced, as well as calcium-phosphate resorption activity and expression of pro-osteoclatic transcription factor c-Fos. IFN-alpha modulation of angiogenesis was studied by analysis of proliferation, survival, and migration of a bone endothelial cell line (BBE), and by the analysis of pro-angiogenic factor expression in RCC cell lines. IFN-alpha inhibited bone endothelial cell proliferation and the expression of FGF-2, while the vascular endothelial growth (VEGF) did not show any significant variation. Moreover, IFN-alpha inhibited the migration induced by the RCC through the impairment of fibroblast growth factor-2 (FGF-2) secretion. These data demonstrate multiple activities of IFN-alpha on renal cancer-induced bone disease, in addition to its recognized role as a cytotoxic and immunomodulatory agent, because they indicate its ability to reduce bone resorption and to impair tumor-associated angiogenesis, and they also suggest the use of IFN-alpha to treat skeletal metastases of other carcinomas.

Angiogenesis Inhibitors↗

PubMed2006

Evaluation of bone healing enhancement by lyophilized bone grafts supplemented with platelet gel: a standardized methodology in patients with tibial osteotomy for genu varus.

Orthopedic practice may be adversely affected by an inadequate bone repair that might compromise the success of surgery. In recent years, new approaches have been sought to improve bone healing by accelerating the rate of new bone formation and the maturation of the matrix. There is currently great interest in procedures involving the use of platelet gel (PG) to improve tissue healing, with satisfactory results both in vitro and in maxillofacial surgery. Otherwise, to our knowledge, only a preliminary clinical study was undertaken in the orthopedic field [Kitoh et al., Bone 2004;35:892-898] and the efficacy of PG is still controversial. Our paper focuses on the effect on bone regeneration by adding PG to lyophilized bone chips used for orthopedic applications. The clinical model and the laboratory methodology were standardized. As a clinical model, we employed the first series of patients of a randomized case-control study undergoing high tibial osteotomy (HTO) for genu varus. Ten subjects were enrolled: in 5 patients lyophilized bone chips supplemented with PG were inserted during tibial osteotomy (group A); 5 patients were used as a control (group B) and lyophilized bone chips without gel were applied. Forty-five days after surgery, computed tomography scan guided biopsies of grafted areas were obtained and the bone maturation was evaluated by a standardized methodology: the osteogenic and angiogenic processes were semi-quantitatively characterized by using histomorphometry, and the mineral component of the lyophilized and host bone was analyzed by using X-ray diffraction technique with sample microfocusing and microradiography. Lyophilized bone with PG seems to accelerate the healing process, as shown by new vessel formation and deposition of newly formed bone, with no evidence of inflammatory cell infiltrate, when compared with lyophilized bone without gel. On the contrary, lyophilized bone undergo a resorption process, and a fibrous tissue often fills the spaces between chips. A histiocytic/giant-cell reaction is sometimes present. Otherwise, no differences have been found concerning microstructure. Our findings show the reliability of the methodology used to monitor early bone repair. The completion of the study and the evaluation of the ultimate clinical outcome are necessary in order to verify PG in vivo effects in orthopedic surgery.

Adult↗

PubMed2006

In vivo study on the healing of bone defects treated with bone marrow stromal cells, platelet-rich plasma, and freeze-dried bone allografts, alone and in combination.

The repair of confined trabecular bone defects in rabbits treated by autologous bone marrow stromal cells (BMSC), platelet-rich plasma (PRP), freeze-dried bone allografts (FDBA) alone and in combination (BMSC + PRP; FDBA + BMSC; FDBA + PRP; FDBA + PRP + BMSC) was compared. A critical size defect was created in the distal part of the femurs of 48 adult rabbits. Histology and histomorphometry were used in the evaluation of healing at 2, 4, and 12 weeks after surgery. The healing rate (%) was calculated by measuring the residual bone defect area. Architecture of the newly formed bone was compared with that of bone at the same distal femur area of healthy rabbits. The defect healing rate was higher in PRP + BMSC, FDBA + PRP, FDBA + BMSC, and FDBA + PRP + BMSC treatments, while lower values were achieved with PRP treatment at all experimental times. The highest bone-healing rate at 2 weeks was achieved with FDBA + PRP + BMSC treatment, which resulted significantly different from PRP (p < 0.05) and BMSC (p < 0.05) treatments. At 4 weeks, the bone-healing rate increased except for PRP treatment. Finally, the bone-healing rate of FDBA + PRP, FDBA + BMSC, and FDBA + PRP + BMSC was significantly higher than that of PRP at 12 weeks (p < 0.05). At 12 weeks, significant differences still existed between PRP, BMSC, and FDBA groups and normal bone (p < 0.05). These results showed that the combination of FDBA, BMSC and PRP permitted an acceleration in bone healing and bone remodeling processes.

Animals↗

PubMed2006

Differences in ion release after ceramic-on-ceramic and metal-on-metal total hip replacement. Medium-term follow-up.

Modern metal-on-metal bearings produce less wear debris and osteolysis, but have the potential adverse effect of release of ions. Improved ceramic-on-ceramic bearings have the lowest wear of all, but the corrosion process has not been analysed. Our aim was to measure the serum ion release (ng/ml) in 23 patients having stable hip prostheses with a ceramic-on-ceramic coupling (group A) and to compare it with the release in 42 patients with a metal-on-metal bearing (group B) in the medium term. Reference values were obtained from a population of 47 healthy subjects (group C). The concentrations of chromium, cobalt, aluminium and titanium were measured. There was a significant increase of cobalt, chromium and aluminium levels (p < 0.05) in group B compared with groups A and C. Group A did not differ significantly from the control group. Despite the apparent advantage of a metal-on-metal coupling, especially in younger patients with a long life expectancy, a major concern arises regarding the extent and duration of ion exposure. For this reason, the low corrosion level in a ceramic-on-ceramic coupling could be advantageous.

Adult↗

PubMed2005

Systemic cross-linked N-terminal telopeptide and procollagen I C-terminal extension peptide as markers of bone turnover after total hip arthroplasty.

There is no diagnostic, non-invasive method for the early detection of loosening after total hip arthroplasty. In a pilot study, we have analysed two serum markers of bone remodelling, procollagen I C-terminal extension peptide (PICP) and cross-linked N-terminal telopeptide (NTx), as well as the diagnostic performance of NTx for the assessment of osteolysis. We recruited 21 patients with loosening (group I), 18 with a well-fixed prosthesis (group II) and 17 at the time of primary arthroplasty for osteoarthritis (OA) (group III). Internal normal reference ranges were obtained from 30 healthy subjects (group IV). The serum PICP level was found to be significantly lower in patients with OA and those with loosening, when compared with those with stable implants, while the NTx level was significantly increased only in the group with loosening, suggesting that collagen degradation depended on the altered bone turnover induced by the implant. This hypothesis was reinforced by the finding that the values in the pre-surgery patients and stable subjects were comparable with the reference range of younger healthy subjects.A high specificity and positive predictive value for NTx provided good diagnostic evidence of agreement between the test and the clinical and radiological evaluations. The NTx level could be used to indicate stability of the implant. However, further prospective, larger studies are necessary.

Adult↗

PubMed2005

Effects of activated platelet concentrates on human primary cultures of fibroblasts and osteoblasts.

BACKGROUND: Platelet alpha granules contain growth factors released into the surrounding environment during activation. This property has been used in clinical medicine to accelerate the repair process by activating in vitro autologous platelets with thrombin and has also been proposed to promote the proliferation of bone cells. The aim of this research was to assess the effect of platelet concentrates activated with thrombin on human gingival fibroblasts and human osteoblasts from trabecular bone. METHODS: Platelet concentrates, activated with bovine thrombin, were added to the cells in serum-free medium. The cultures were assessed for proliferation by vital stain and cell count after 72-hour incubation. Alkaline phosphatase activity was tested after 72-hour incubation on the osteoblast lysates by a colorimetric assay. After 21 days the formation of mineral nodules was tested in the osteoblast cultures by alizarin red staining. The effects of the activated platelet concentrates (APC) were compared with the serum-free medium (SF), or with platelet-poor plasma added medium (PPP). RESULTS: The fibroblast growth in the presence of APC was higher, though not significantly, than SF. APC resulted in a nonsignificant decrease in proliferation and alkaline phosphatase expression in osteoblasts, compared both to serum free medium, and PPP. Mineralization was only modestly increased after incubation with APC in comparison with serum-free medium. CONCLUSIONS: There were no statistical differences in fibroblast proliferation, or in osteoblast growth and functions between serum-free conditions and the platelet gel treatment. Therefore, neither fibroblast proliferation nor osteoblast growth and functions were affected by the activated platelet concentrates in vitro.

Alkaline Phosphatase↗

PubMed2004

The influence of alumina and ultra-high molecular weight polyethylene particles on osteoblast-osteoclast cooperation.

Particle-induced macrophage activation, mainly by UHMWPE wear, has been recognized as the biological mechanism leading to periprosthetic bone resorption, which is responsible for the loosening of the total hip replacements (THR). Ceramic-on-ceramic implants have been advocated as a means of reducing wear products. Many studies investigated the effect of alumina (Al(2)O(3)) particles on monocytes/macrophages, but only limited information are available on their participation to bone turnover. An in vitro model was performed to investigate how Al(2)O(3) and UHMWPE particles may influence the osteoblast-osteoclast interaction: human osteoblasts (HOB) were obtained from trabecular bone, while osteoclasts were derived from peripheral blood mononuclear cells (PBMC) of healthy donors. The amount of IL6, TNF alpha, GM-CSF, and other factors acting on the bone turnover, i.e. the 'receptor activator of NF kappa B' ligand (RANKL) and osteoprotegerin (OPG), was detected in culture medium of particle-challenged HOB (HOB-CM). The Al(2)O(3) and UHMWPE particles did not affect either cell viability or TNF and GM-CSF release, while the increase in IL6 release seemed to be dependent on the particle concentration. UHMWPE increased the release of RANKL from HOB, while OPG and OPG-to-RANKL ratio were significantly inhibited. The ability of HOB-CM to promote osteoclastogenesis was tested via osteoblast/monocyte cooperation: after seven days of culture UHMWPE HOB-CM induced a large amount of multinucleated TRAP-positive giant cells, as well as significantly reduced the amount of IL6, GM-CSF and RANKL in the supernatant. With regard to the inductive effect on the osteoclastogenesis, our results show that the Al(2)O(3) wear debris are less active.

Aluminum Oxide↗

PubMed2004

Evaluation of osteoblast-like cell response to Proroot MTA (mineral trioxide aggregate) cement.

Some endodontic sealers have been shown to cause local and systemic effects, mainly due to microleakage of chemicals from the sealer. To avoid the risk of toxic effects in vivo, the biological compatibility of filling materials has to be assessed. In vitro compatibility of Proroot MTA cement in comparison with two different fillers used in clinical practice, was examined by testing the adherence, viability, proliferation and secretion of collagen of osteoblast-like cells. In our experimental system, Saos-2 cells challenged with Proroot MTA for 24 and 72 h showed a better behaviour than the cells exposed to the other compounds under assay. We found that the cells attached to the rough surface of Proroot MTA cement and spread onto the rough surface. Moreover, the cells on Proroot MTA were viable, grew, and released some collagen even at 72 h, while cell metabolism and growth was dramatically reduced onto sEBA and amalgam surfaces. A parallel behaviour was found after the cells were challenged with extracts of the different fillers. In conclusion, according to our in vitro study, Proroot MTA showed a good interaction with bone-forming cells: such behaviour may partially account for its satisfying clinical performance.

Aluminum Compounds↗

PubMed2003

Biologic effects of surface roughness and fluorhydroxyapatite coating on osteointegration in external fixation systems: an in vivo experimental study.

The concomitant influence of surface roughness and fluorhydroxyapatite (FHA) coating of titanium (Ti) implants on bone response was investigated. For this purpose, titanium screw-shaped implants with a lower degree (Y371) and a higher degree (TiPore300) of surface roughness, coated with FHA and uncoated, were transversally inserted into the diaphyses of sheep tibiae for 12 weeks. Four sheep received Y371 (group A) and Y371 + FHA (group B) screws and four sheep received TiPore300 (group C) and TiPore300 + FHA (group D) screws. For each type of material, the morphology and microstructure of implant-facing bone were evaluated. The host bone of each tibia was used as a control. In all groups the bone tissue did not reach a complete maturation. The higher degree of roughness, perhaps due to an excessive irregularity of the surface, induced the worst osteointegration: a fibrous tissue layer between screw and new bone tissue was often present. Nevertheless, as viewed by XRD, no crystallographic change of the apatite lattice was observed in any of the implants. In contrast, the microhardness value, an index of bone mineralization, was higher in the uncoated screws and decreased progressively in the following order: group C > group A > group B > group D. The association of plasma spraying with roughness treatment constitutes a complex system that seems to interfere with bone mineralization. A chemical change of the surface, perhaps with more Ti release or more coating degradation, could be responsible for such impairment. The authors emphasize the necessity for simultaneous evaluation of surface topography and chemistry as well as an improvement in plasma-spraying and post-processing techniques and in standard procedures for materials characterization.

Animals↗

PubMed2003

Ion release in stable hip arthroplasties using metal-on-metal articulating surfaces: a comparison between short- and medium-term results.

The use of metallic heads articulating with metallic cups could solve the problem of polyethylene (PE) wear in total hip replacement (THR) with metal-on-PE bearings. A conspicuous release of metal ions from new models of metal-on-metal bearings has been found in the short-term, but it is yet unclear whether the medium-term corrosion rate is high or, on the contrary, it becomes negligible, because of the continuous surface finishing. Our purpose was to compare the serum ion values (nanograms per milliliter) in 15 patients with metal-on-metal stable prosthesis (Group A), in the short-term (subgroup A(1); mean follow-up: 24 mo) and medium-term (subgroup A(2); mean follow-up: 52 mo), in order to determine whether the ion release decreased with time of implant. Chromium (Cr), cobalt (Co), molybdenum (Mo) and aluminum (Al) were analyzed. Twenty-two presurgical patients were used for comparison (Group B). The reference range was obtained from a population of 27 healthy subjects (Group C). Co and Cr levels in the medium-term (subgroup A(2)) were not decreased in comparison with the short-term values (subgroup A(1)) and were significantly higher (p < 0.001) than presurgical and reference values. Otherwise, Mo and Al concentrations were not significantly increased in comparison with reference values. In conclusion, despite the apparent advantage of metal-on-metal coupling, especially in younger patient populations, there is a major concern about the extent and duration of the relevant "internal" exposure to Cr and Co ions. This exposure should be carefully monitored, in order to clarify the biologic effects of ion dissemination and, consequently, to identify risks concerning long-term toxicity of metals.

Adult↗

PubMed2003

Osteoblast growth and function in porous poly epsilon -caprolactone matrices for bone repair: a preliminary study.

Current methods for the replacement of skeletal tissue involve the use of autografts, allografts and, recently, synthetic substitutes, which provide a proper amount of material to repair large bone defects. Engineered bone seems a promising approach, but a number of variables have to be set prior to any clinical application. In this study, four different poly caprolactone-based polymers (PCL) were prepared and tested in vitro using osteoblast-like Saos-2 cells. Differences among three-dimensional polymers include porosity, addition of hydroxyapatite (HA) particles, and treatment with simulated body fluid. Biochemical parameters to assess cell/material interactions include viability, growth, alkaline phosphatase release, and mineralization of osteoblastic cells seeded onto three-dimensional samples, while their morphology was observed using light microscopy and SEM. Preliminary results show that the polymers, though degrading in the medium, have a positive interaction with cells, as they support cell growth and functions. In the short-term culture (3-7 days) of Saos-2 on polymers, little differences were found among PCL samples, with the presence of HA moderately improving the number of cells onto the surfaces. In the long term (3-4 weeks), it was found that the HA-added polymers obtained the best colonization by cells, and more mineral formation was observed after coating with SBF. It can be concluded that PCL is a promising material for three-dimensional scaffold for bone formation, and the presence of bone-like components improves osteoblast activity.

Biocompatible Materials↗

PubMed2002

Ion release in patients with metal-on-metal hip bearings in total joint replacement: a comparison with metal-on-polyethylene bearings.

Polyethylene (PE) wear has been shown to be a problem in long-term joint replacement using metal-on-PE bearing. The use of metallic heads articulating with metallic cups could solve this problem: success will be enhanced if wear and corrosion of the articulating surfaces are maintained at a low level. New models with metal-on-metal bearing have been proposed, to be used mainly for young subjects: such coupling seems to have a reduced release, but it is unclear yet if the medium-term corrosion rate is really negligible or, on the contrary, it is significantly higher than in the metal-on-PE bearing. Aim of our study was the comparison of ion release in the serum of two groups of patients who had the same type of stable cementless prosthesis, but different bearing: twenty-six patients with metal-on-metal (Group A) and fifteen patients with metal-on-PE bearing (Group B) were examined. The follow-up was 14-38 months for group A and 18-34 months for group B. The serum concentration of chromium (Cr), cobalt (Co) and molybdenum (Mo) was measured. Twenty-two patients before surgery were used for comparison (Group C). The reference values were obtained from a population of twenty-two healthy subjects (Group D). Our findings indicate that metal-on-metal bearings produce a significantly higher systemic release of cobalt and chromium (ng/ml) when compared with levels found in metal-on-PE, pre-surgery and reference groups. Such a high release should induce to improve the bearing materials or, at least, to study the biologic fate of metal ions and consequently their long-term effects. In such a way a risk-to-benefit ratio for the patient could be established.

Adult↗

PubMed2002

In vitro testing of the potential for orthopedic bone cements to cause apoptosis of osteoblast-like cells.

The purpose of this study was to investigate in vitro the apoptosis- and/or necrosis-inducing potential of polymethylmethacrylate (PMMA)-based bone cements for prosthetic surgery. Four bone cements widely used in orthopedics were tested as extracts onto osteoblast-like MG-63 cells and for comparison, HL-60 cells, which are remarkably sensitive to apoptotic stimuli. Neutral red uptake (NRU) was used to measure cell viability while Hoechst 33258 staining was used to detect DNA content. Apoptosis was characterized using a BrdU-based ELISA assay for DNA fragmentation and examined by fluorescence microscopy using acridine orange and propidium iodide staining of nuclei. The generation of reactive oxygen species (ROS), which could mediate apoptosis, was verified using dichlorofluorescein-diacetate (DCFH-DA) oxidation to DCF. After 24 h of challenge of the cells with the four cement extracts, the viability of either MG-63 or HL-60 cells was found to be unaltered, as recorded by NRU. Apoptotic cell death was induced by three cements in HL-60, whereas MG-63 cells were significantly affected by the four cements tested: the finding of DNA fragments both in the cytoplasm and supernatants of MG-63 after 24 h demonstrated that these cells underwent late-apoptosis secondary necrosis. Fluorescent staining of the nuclei confirmed the results obtained with the ELISA test. Oxygen free radicals were elicited by two cements in HL-60 cells, while MG-63 did not generate ROS in response to cements. This study helps to gain more insight into the mechanism of cell death induced by PMMA-based cements and suggests apoptosis of osteoblasts as a part of the tissue reaction around cemented prostheses.

Apoptosis↗

PubMed2002

Platelet release of transforming growth factor-beta and beta-thromboglobulin after in vitro contact with acrylic bone cements.

Three methacrylate-based bone cements used for the fixation of joint prostheses were evaluated: Sulfix-60 (Sulzer Orthopedic Inc., Baar, Switzerland). CMW1 (DePuy International Ltd., England). and CMW2 (DePuy International Ltd., England). The cements after polymerization were put in contact in vitro with platelet-rich plasma. Plasma, in contact only with siliconized glass, was used as a negative control. After contact, platelet number. beta-thromboglobulin (beta-TG), and transforming growth factor-beta1 (TGF-beta1) were determined. The Student's paired t test showed that the ccments induced no significant modifications of platelet number. CMWI and Sulfix-60 determined a significant increase in beta-TG compared with the negative control. All cements determined a significant increase in TGF-beta1. Significant differences were also seen in the levels of beta-TG and TGF-beta1 between cements with a content of benzoyl peroxide < 1 (Sulfix-60) and those with a content > 1 (CMW1 and CMW2). The cement with zirconium dioxide (Sulfix-60) produced higher levels of beta-TG and TGF-beta1, compared to those with barium sulphate (CMW1 and CMW2). In conclusion, all the cements induced the secretion of TGF-beta1 CMW1 and Sulfix-60 determined also a significant release of beta-TG. Platelet activation induced by the cements from one side could contribute to the pathogenesis of deep venous thrombosis, that often occurs after prosthetic implant and is caused also by other factors, including surgical trauma and venous stasis. From the other side, activated platelets can release growth factors favoring bone formation.

Acrylic Resins↗

PubMed2002

Gene expression of bone-associated cytokines in MG63 osteoblast-like cells incubated with acrylic bone cement extracts in minimum essential medium.

This study examined the effects of in vitro challenge with four polymerized acrylic bone cements (Sulfix-60, CMW 1, CMW 2, and CMW 3) on the expression of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and transforming growth factor-beta1 (TGF-beta1) mRNAs in the osteoblast-like cell line MG63. The extracts of the cements in minimal essential medium (MEM) were tested following 1-h and 7-day curing. A semi-quantitative analysis of the cytokine-specific mRNAs was carried out by agarose gel densitometry and expression was compared with the GAPDH housekeeping gene. The ratio between cytokine gene expression and GAPDH expression was calculated. The mRNA specific for the bone-resorbing cytokines IL-1beta and IL-6 was low in basal conditions. IL-1beta mRNA increased only after incubation with the extract of CMW 1 following 1-h curing. The mRNA specific for the bone-resorbing cytokine IL-6 also increased after contact with CMW 1 at both curing times. Sulfix-60 and CMW 3 following 7-day curing, but not after 1 h, induced higher levels of IL-6 mRNA than the control. CMW 2 after 1-h curing constantly determined the expression of IL-6 mRNA, but at low levels. The mRNA specific for TGF-beta1 was also expressed by the MG63 osteoblast-like cells in basal conditions. The levels increased after contact with Sulfix-60 after 7-day curing and with CMW 1 after 1-h curing. CMW 2 after 7-day curing decreased TGF-beta1 mRNA. In conclusion, the highest expression of the cytokines IL-1beta, IL-6, and TGF-beta1 mRNA was determined by CMW 1. If the results are confirmed in vivo, the increased expression of the osteolytic cytokines induced by the bone cement might result in loosening of the prosthesis, even with all the restrictions of an in vitro study on continuous cell lines.

Bone Cements↗

PubMed2002

Platelet activation after in vitro contact with seven acrylic bone cements.

Seven acrylic bone cements were evaluated: Cemex Rx (Tecres S.p.a., Italy), Cemex Isoplastic (Tecres S.p.a., Italy), Zimmer Low Viscosity Cement (L.V.C., Zimmer, IN, USA), Zimmer bone cement - dough type (Zimmer, IN, USA), CMW (DePuy International Ltd., UK), Cerim LT (Cremascoli S.r.l., Italy), and Palacos (Merck, Wehreim, Germany). The cements after polymerization were put in contact in vitro with platelet-rich plasma. Plasma in contact only with siliconated glass was used as the negative control. After contact, platelet number, beta-thromboglobulin (beta-TG), and transforming growth factor-beta1 (TGF-beta1) were determined. The Wilcoxon signed rank test showed Palacos R and L.V.C. induced a significant decrease of platelet number compared with the negative control. All cements determined a significant increase in beta-TG. CMW 3, Palacos, L.V.C., and Zimmer dough type determined a significant increase in TGF-beta1 compared with the negative control.

Biocompatible Materials↗

PubMed2001

Evaluation of tissue-factor production by human endothelial cells incubated with three acrylic bone cements.

The effect of three methacrylate-based cements used for the fixation of joint prostheses on tissue-factor production by human umbilical vein endothelial cells was evaluated in vitro. The extracts in the culture medium of the cements were tested after 1-h and 7-day curing. The endothelial cells were incubated with the cement extracts for 4 h, and then the tissue factor was determined in cell lysates with both the recalcification time and enzyme immuno assay. The cements did not induce significant production of tissue factor and, therefore, did not activate the extrinsic pathway of coagulation within the limits of the mechanism considered.

Ascorbic Acid↗

PubMed2001

Cytotoxicity, blood compatibility and antimicrobial activity of two cyanoacrylate glues for surgical use.

The biocompatibility of two cyanoacrylate surgical glues (Glubran and Glubran 2), supplied by General Enterprise Marketing, Viareggio, Lucca, Italy, was tested through cytotoxicity and blood compatibility tests and the evaluation of antimicrobial activity. Cytotoxicity and blood compatibility tests were performed on the polymerized glues. Using the neutral red uptake test, the extracts from Glubran and Glubran 2 after polymerization were non-toxic to L929 cells only when diluted 1: 10 with culture medium. Glubran and Glubran 2 induced a significant decrease of activated partial thromboplastin time (APTT), which is favourable with regard to the desired haemostasis. The APTT shortening determines a haemostatic effect and therefore contribute to the tissue adhesion induced by the glues. Otherwise, no significant variation of prothrombin activity, fibrinogen, platelet number, total and differential leukocyte count was induced by the glues, which, in addition, did not show haemolytic effect. There was no difference between Glubran and Glubran 2 regarding haemocompatibility. The antimicrobial ability of the unpolymerized glues was tested onto Bacillus subtilis var. niger for 3 weeks: neither Glubran nor Glubran 2 were found effective in this respect. In conclusion, we can assume that cytotoxicity was severe with the undiluted glues, but was acceptable when glues were diluted. On the contrary, blood compatibility was acceptable for the intended use of the glues. No difference was found between Glubran and Glubran 2 after polymerization.

Animals↗