Drug – bio-affecting and body treating compositions – Enzyme or coenzyme containing – Hydrolases
Reexamination Certificate
1996-05-17
2003-09-02
Marx, Irene (Department: 1651)
Drug, bio-affecting and body treating compositions
Enzyme or coenzyme containing
Hydrolases
C424S094100, C424S542000
Reexamination Certificate
active
06613324
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a fibrinogen-containing adhesive which is intended for the gluing of biological tissues, in particular tissues of the human body.
The physiological wound healing is based on a complex, multistep interaction between proteins, cells and corpuscles of the blood on the one hand, and structure proteins, polysaccharides and cells of the wound on the other hand, finally leading to the filling of the wound with tissue.
Mechanical measures, such as sewing, wedging, nailing and screwing techniques using natural or synthetic, organic or mineral auxiliaries, are often used for the sealing and reconstitution of tissular structures which were broken by surgical interventions or traumatic or pathological influences.
Besides these mechanical procedures, also synthetic chemical gluing systems have been recently tested for the sealing of tissues. Mainly synthetic resin adhesives on the base of polyacrylic acid esters, such as 2-cyanoacrylic acid isobutyl ester (BUCRYLATE™), have been used. However, polyacrylic adhesives give a stiff gluing area which does not fit the plasticity and elasticity of soft tissues and organs, and which causes inflammations due to mechanical irritation. Today, the application of such synthetic resin adhesives is therefore limited to the field of odontology and some special orthopaedic surgical indications.
In order to overcome the mentioned disadvantages of synthetic resin adhesives, it has been tried to use proteins participating in the physiological wound healing as wound-sealing agents. Thus, a commercial product (TISSUCOL
R
kit, Immuno AG, Vienna, Austria) has the following composition: A) so-called cryoprecipitate of human blood, a mixture of plasminogen-containing fibrinogen, fibronectin and coagulation factor XIII present as an inactive proenzyme, B) bovine thrombin, C) aprotinin solution and D) calcium chloride solution. Components A and B are lyophilizates which are dissolved in water before use, under dosed addition of components C and D, respectively. The viscous solution A/C, containing 75 to 115 mg of clottable protein per ml, and the solution B/D, containing 4 to 500 units of thrombin according to its application, are then applied on the wound surface either simultaneously or successively, and allowed to polymerize. The thrombin contained in the system catalyzes the splitting of fibrinopeptides (A and B) from fibrinogen and the formation of fibrin monomers as well as the activation of the fibrin-stabilizing factor XIII. Depending on the applied dose of thrombin, an adhesive gluing area sealing the wound defect is formed within few seconds to some minutes, area which is fibrinolytically decomposed and dissolved more or less rapidly according to the aprotinin concentration added.
The bovine thrombin present in gluing systems is an unstable, heat-sensitive enzyme, in which viruses and prions cannot be inactivated or weakened either by physical or chemical measures without destruction of its enzymatic activity, and which, therefore, may be the carrier of bovine spongiform encephalitis (BSE) and of viruses pathogenic to mammals. Furthermore, bovine thrombin is a potent antigen, which can trigger off anaphylactic reactions in the human organism. Although human thrombin is not antigenic, it involves the risk of a transmission of hepatitis and HIV, since it cannot be freed from those viruses either by heat treatment or by chemical measures due to its sensitivity. In the blood, there is finally an inhibitor of thrombin, the so-called antithrombin III, which can neutralize the thrombin of the adhesive. Since this thrombin-inhibiting effect of antithrombin III is potentiated by the anticoagulant heparin, a thrombin-containing adhesive cannot be used, or only under application of high thrombin concentrations, in those patients who undergo a heparin treatment. However, the higher the thrombin concentration in the adhesive, the higher the risk of anaphylactic and thrombo-embolic reactions. In circulating blood, thrombin migrating from the gluing site triggers off an activation of the platelet adhesion, aggregation and release reactions and acts therefore thrombogenic. In order to reduce the risk of anaphylactic and thromboembolic complications to a minimum, it has to be taken great care to keep thrombin away from the tissue which has not to be treated around the wound, during the application of thrombin-containing wound sealants. Thrombin should on no account reach the circulating blood because it can induce thromboses and embolisms due to its multiple activating effects on blood platelets, plasma coagulation factors and endothelium cells. Even in case of careful application, the gluing site constitutes an accumulation of thrombin which can induce intravasal coagulation and against which the organism can develop immunological defence reactions. For these reasons, thrombin-containing fibrin adhesives are only applicable with significant restrictions and are in no way appropriate in case of surgical operations on blood vessels.
Furthermore, due to the short preservability of the dilution, thrombin has to be used in a lyophilized form, what considerably increases the price of the gluing system and complicates its use by an additional dissolution process.
A common disadvantage of all adhesives the clottable protein of which is introduced in the form of a cryoprecipitate lies in their viscous consistency which makes an accurate application impossible. Such viscous or pasty glues are not appropriate in case of microsurgical applications or operations which are performed through the endoscope.
SUMMARY OF THE INVENTION
It has now been tried to overcome the disadvantages of thrombin-containing fibrin adhesives by allowing a fibrinogen-splitting enzyme from a snake venom instead of thrombin as the polymerization inducer to act on a fibrinogen-containing cryoprecipitate solution. Contrary to thrombin which splits fibrinopeptides A and B from fibrinogen and thereby induces an end-to-end and side-by-side polymerization of fibrin, these snake venom enzymes specifically catalyze the exclusive splitting of fibrinopeptide A, which leads to formation of a fragile fibrin which is unsuitable for sealing purposes.
It has now surprisingly been found that the splitting of fibrinopeptide A induced by the snake venom enzyme batroxobin in the presence of calcium ions, in a solution of purified human fibrinogen, leads to the formation of a co-polymerizate with remarkable biophysical properties if activated factor XIII (factor XIIIa) is added to the mixture. The use of purified human fibrinogen, purified human fibronectin and purified human activated factor XIII allows manufacture of lyophilizates of mixtures, which, after reconstitution with water, yield components of a gluing system that have various viscosities and that can be easily and accurately applied.
The present invention relates to an adhesive for the gluing of tissues of the human body which contains
(a) fibrinogen,
(b) a fibrinogen-splitting enzyme,
(c) a calcium ion-providing substance and
(d) blood coagulation factor XIII, and which comprises the blood coagulation factor XIII in an activated form (factor XIIIa) and a fibrinogen-splitting snake venom enzyme as the fibrinogen-splitting enzyme.
DETAILED DESCRIPTION OF THE INVENTION
Fibrinogen-splitting snake venom enzymes can be obtained from venoms of the snake family Viperidae. Up to now, 27 fibrinogen-splitting enzymes from venoms of the snake family Viperidae have been isolated and characterized (H. Pirkle and K. Stocker, Thrombin-like enzymes from snake venoms: An inventory. Thromb. Haemostas. 65, 444-450, 1991). Two of these enzymes, ancrod and batroxobin, are used in human medicine as antithrombotic drugs for therapeutic defibrinogenation. They are highly stable in solution, are not inhibited by antithrombin III even in the presence of heparin, are well tolerated by the human organism as very weak antigens, and specifically act on fibrinogen exclusively. Other clotting factors or thrombocyte functions are neither a
Blombäck Birger
Hessel Birgit
Olsson Per
Stocker Kurt
Strömberg Lennart
Kilcoyne John M.
Marx Irene
LandOfFree
Adhesive for the gluing of biological tissues does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adhesive for the gluing of biological tissues, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adhesive for the gluing of biological tissues will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3006083