Cytotoxicity and cellular uptake of newly synthesized fucoidan-coated nanoparticles.

The aim was to synthesize and characterize fucoidan-coated poly(isobutylcyanoacrylate) nanoparticles. The nanoparticles were prepared by anionic emulsion polymerization (AEP) and by redox radical emulsion polymerization (RREP) of isobutylcyanoacrylate using fucoidan as a new coating material. The nanoparticles were characterized, and their cytotoxicity was evaluated in vitro on J774 macrophage and NIH-3T3 fibroblast cell lines. Cellular uptake of labeled nanoparticles was investigated by confocal fluorescence microscopy. Results showed that both methods were suitable to prepare stable formulations of fucoidan-coated PIBCA nanoparticles. Stable dispersions of nanoparticles were obtained by AEP with up to 100% fucoidan as coating material. By the RREP method, stable suspensions of nanoparticles were obtained with only up to 25% fucoidan in a blend of polysaccharide composed of dextran and fucoidan. The zeta potential of fucoidan-coated nanoparticles was decreased depending on the percentage of fucoidan. It reached the value of -44 mV for nanoparticles prepared by AEP with 100% of fucoidan. Nanoparticles made by AEP appeared more than four times more cytotoxic (IC(50) below 2 µg/mL) on macrophages J774 than nanoparticles made by RREP (IC(50) above 9 µg/mL). In contrast, no significant difference in cytotoxicity was highlighted by incubation of the nanoparticles with a fibroblast cell line. On fibroblasts, both types of nanoparticles showed similar cytotoxicity. Confocal fluorescence microscopy observations revealed that all types of nanoparticles were taken up by both cell lines. The distribution of the fluorescence in the cells varied greatly with the type of nanoparticles.

A comparison of a cyanoacrylate [corrected] glue (Glubran) vs. fibrin sealant (Tisseel) in experimental models of partial pulmonary resection and lung incision [corrected] in rabbits.

INTRODUCTION: Bronchopleural fistulas (BPF) and air leaks (AL) present major complications after pulmonary resection. Various tissue sealants have been proposed for their prevention, e.g., fibrin sealant (FS) and cyanoacrylate glues (CA). Contrary to the safety record of FS, substantial side effects such as foreign body reaction and impaired tissue integration have been reported for CA. This study compares the sealing efficacy and biocompatibility as well as side effects of FS and CA in experimental partial pulmonary resection and lung incision in rabbits. METHODS: 26 New Zealand white rabbits (3 kg) were randomized to one of the three groups: partial pulmonary resection (A, acute model; n = 7 FS/ 7CA), lung incision [2 (B; n = 3 FS/ 3 CA)], and 14-day observation period (C; n = 3 FS/ 3 CA). In all groups (A, B, and C), FS was considered as control and CA as treatment. Surgery was carried out in general anaesthesia and mechanical ventilation. For partial lung resection a median thoracotomy was performed and the apex of the left median lobe was resected and the parenchymal surface covered with 0.09 ml of FS and CA. The thoracic cavity was filled with ringer solution after 5 minutes. The inspiratory minute volume (IMV) was increased by 0.02 l after every 4th inspiration. In groups B and C, a left lateral thoracotomy was performed in the 4th intercostal space and the left median lobe was incised with a scalpel. The incision was covered with 0.5 ml of FS or CA. At autopsy (B and C) the operation site was assessed macroscopically. Histology was performed in all animals. RESULTS: In terms of sealing purposes, FS and CA yielded comparable results in all groups. CA elicited a substantial increase of tissue temperature in the acute phase immediately after application (A). After 14 days CA residues were found, whereas FS was completely degraded. Histology showed a pronounced inflammatory response to CA but not to FS. We conclude that although the effect of airtight sealing was equally satisfying, our results emphasize that FS is preferable to CA for the prevention of BPF and AL due to superior biocompatibility and degradability. Longterm effects of CA residues on pulmonary tissue require further experimental testing.

In vitro and in vivo studies for modified ethyl cyanoacrylate regimens for sclerotherapy.

Cyanoacrylates have known for their ability to polymerize rapidly in the presence of traces of weakly basic moieties such as water. The tissue adhesive, Histoacryl(R) (N-butyl 2-cyanoacrylate), has been reported to control bleeding through endoscopic sclerotherapy. But the commercially available Histoacryl(R) is expensive, and it has the problem like other cyanoacrylates that the glue tends to flow/run away from the point of application, which is inherent to the low viscosity, making precise application difficult. In this study, ethyl cyanoacrylate (ECA), the main constituent of "super glue," was employed instead of Histoacryl(R) due to its lower cost. The aim of the research is to modify the compositions of ECA regimen and evaluate its feasibility for sclerosant application through both in vitro flow circuit model and in vivo animal tests. It was noted that the difference in the relative hardening rate between the in vitro Hepes-Tyrodes buffer flowing model and the in vivo rat model for the ECA and Histoacryl(R) was related to the existence of the blood protein, such as albumin, in the physiological milieu. It was also noticed that the ECA setting rate was greatly increased either in Hepes-Tyrodes buffer or in blood (to a comparable rate as Histoacryl(R) in vivo) by adding a few doses of caffeine, which acts as a polymerization initiator. This would lead to far better injection precision during sclerotherapy. Furthermore, in vivo histological examination for the occluded lumen of the rat's inferior vena cava and a clinical piglet portal vein occlusion experiment have suggested this new sclerosant regimen, caffeine/ECA, is of great promise in endoscopic sclerotherapy.

[Osteosynthesis with an adhesive in skeletal fractures: an experimental study]. / L'osteosintesi con collante nelle fratture scheletriche: studio sperimentale.

A-cyanoacrylate proves to be an advanced means of osteosynthesis. It is particularly indicated for short bone fragments in the articular and comminuted fractures, where a perfect anatomic reduction is required. It is shown to be non-toxic for bone and surrounding tissues and to be endowed with a remarkable chemical bond. It is easily applied and inexpensive. The results are very interesting and stimulate continuation of the studies. The authors think a-cyanoacrylate (or a derivative) is the future of biological osteosynthesis.

[Evaluation of n-butyl 2-cyanoacrylate for the reconstruction of the arteries in dogs. II. Morphological evaluation]. / Ocena przydatnosci kleju do tkanek 2-cyjanoakrylanu n-butylu do rekonstrukcji uszkodzonych tetnic u psa. II. Ocena morfologiczna.

The microscopic examinations of 56 arteries anastomosed or dressed by 2-cyanoacrylate n-butyl tissue adhesive revealed prolonged inflammation of a foreign body type. The reaction was noticeable even after 93 days. Small parts of adhesive on the arterial surface were surrounded by fibromatosed granulation. However, inside some vessels parietal clots caused by an inaccurate anastomosis and too thick adhesive layer, were found. The long lasting inflammation doesn't eliminate the usefulness of the adhesive as remedy for the facilitation of the small vessels anastomosis.