A novel, automated method of temperature cycling to produce cryoprecipitate

Allogeneic single-donor cryoseal produced from fresh-frozen quarantine apheresis plasma as alternative for multidonor or autologous fibrin sealants

BACKGROUND

Fibrin sealant is a human blood product consisting of two components: cryoprecipitate and thrombin. Commercial fibrin sealants are produced from multidonors, increasing the viral risk, and contain fibrinolytic inhibitors such as tranexamic acid or bovine aprotinin. Autologous fibrin sealants reduce the viral risk and are mostly produced during a surgical procedure or well in advance. Alternatively, the allogeneic single-donor fibrin sealant cryoseal can be used. In this study cryoseal was characterized and the manufacturing consistency of the production process was investigated.

STUDY DESIGN AND METHODS

Cryoseal was produced from plasma collected on apheresis machines using a commercial device. In a research setting the protein composition and recovery were determined. Also, the manufacturing consistency of the production process was tested in a research setting as well as in a routine setting.

RESULTS

In the research setting all produced cryoseal met the quality control requirements of a clotting time of less than 10 seconds and the presence of Factor (F)XIII (qualitative). In the routine setting, one procedure per year did not meet these requirements. The protein composition showed the following mean ± standard deviation (%recovery) results: thrombin 25.7 ± 11.1 IU/mL, fibrinogen 19.9 ± 4.6 (15%) mg/mL, FVIII 15.6 ± 5.4 (44%) IU/mL, FXIII 2.7 ± 0.7 (6%) IU/mL, and plasminogen 1.8 ± 0.2 (4%) U/mL. In both research and routine settings the production process resulted in a consistent product.

CONCLUSION

The cryoseal manufacturing process resulted in a consistent product, which meets the predetermined specifications. The single-donor origin and the absence of fibrinolytic inhibitors make cryoseal a good alternative for multidonor and autologous fibrin sealants.

Fibrin glues in combination with mesenchymal stem cells to develop a tissue-engineered cartilage substitute

Damage of cartilage due to traumatic or pathological conditions results in disability and severe pain. Regenerative medicine, using tissue engineering-based constructs to enhance cartilage repair by mobilizing chondrogenic cells, is a promising approach for restoration of structure and function. Fresh fibrin (FG) and platelet-rich fibrin (PR-FG) glues produced by the CryoSeal(®) FS System, in combination with human bone marrow-derived mesenchymal stem cells (BM-hMSCs), were evaluated in this study. We additionally tested the incorporation of heparin-based delivery system (HBDS) into these scaffolds to immobilize endogenous growth factors as well as exogenous transforming growth factor-β(2). Strongly, CD90+ and CD105+ hMSCs were encapsulated into FG and PR-FG with and without HBDS. Encapsulation of hMSCs in PR-FG led to increased expression of collagen II gene at 2.5 weeks; however, no difference was observed between FG and PR-FG at 5 weeks. The incorporation of HBDS prevented the enhancement of collagen II gene expression. BM-hMSCs in FG initially displayed enhanced aggrecan gene expression and increased accumulation of Alcian blue-positive extracellular matrix; incorporation of HBDS into these glues did not improve aggrecan gene expression and extracellular matrix accumulation. The most significant effect on cartilage marker gene expression and accumulation was observed after encapsulation of hMSCs in FG. We conclude that FG is more promising than PR-FG as a scaffold for chondrogenic differentiation of hMSCs; however, immobilization of growth factors inside these fibrin scaffolds with the HBDS system has a negative impact on this process. In addition, BM-hMSCs are valid and potentially superior alternatives to chondrocytes for tissue engineering of articular cartilage.

Preparation and characterization of human thrombin for use in a fibrin glue

Cryoprecipitate is frequently combined with thrombin to produce a fibrin sealant to enhance haemostasis during surgical procedures. We evaluated the thrombin produced from plasma using the Thrombin Processing Device (TPD)trade mark (Thermogenesis, Rancho Cordova, CA, USA). Plasma (250 mL) was processed in the CryoSeal FS System using the CP-3 disposable to produce cryoprecipitate by automated freezing and thawing. Simultaneously, thrombin was generated using the attached TPD. The cryoprecipitate and thrombin were harvested after approximately 50 min and then frozen and stored at -80 degrees C until analysis of total protein, fibrinogen, factor VIII (FVIII) activity, von Willebrand factor (vWF) and thrombin activity. Sodium dodecyl sulphate (SDS) gel electrophoresis was used to compare thrombin. After combining the thrombin with cryoprecipitate, the rate of clot initiation and strength was measured using a Thromboelastograph (TEG) (Haemoscope Corp, Skokie, IL, USA). Cryoprecipitate was produced, with a fibrinogen concentration of 22 +/- 7.7 g L(-1) (20 +/- 2% recovery), FVIII activity of 14.2 +/- 4.0 IU mL(-1) and vWF of 19.9 +/- 5.2 IU mL(-1). The separate thrombin product had a concentration of 64.3 +/- 16.7 IU mL(-1) of thrombin and a total protein of 0.39 +/- 0.1 g, with SDS gel electrophoresis showing a major band at 37 kD, as did the commercial human thrombin. The TEG curves of cryoprecipitate and TPD-produced or commercial thrombin were compared. The R values (time to clot initiation) were somewhat slower with the TPD-produced thrombin, but the maximum strength (MA) of the clots was similar. In conclusion, human thrombin can be produced during automated cryoprecipitate production. This thrombin is in sufficient concentration to initiate clotting and cross-linking of fibrin from cryoprecipitate to produce an entirely autologous fibrin glue.

Fibrin glues of human origin

Wound healing is the response to injury and the process of tissue repair. Recent advances in cellular and molecular biology have greatly expanded our understanding of this process, which includes chemotaxis, production of matrix protein, cell replication, neovascularization and tissue remodelling. Tissue injury causes the disruption of blood vessels that is responsible for extravasation or haemorrhage of blood constituents and the first step of process in the platelet activation after exposure of collagen. Platelets initiate clotting through the coagulation system. When thrombin is formed, fibrinogen is transformed into fibrin; this is the real first step of wound healing. Fibrin glues reproduce this process and have been widely used in surgery to obtain haemostasis and expedite the process of wound healing. Immunogenicity of xenogenic products and risks of viral or prion disease transmission through commercial products have generated new interest in home-made autologous glues whose complexity was increased when platelets were added to coagulation proteins as a source of cytokines and growth factors. For the preparation of these products, the blood bankers took advantage of their usual technologies and several automated apparatuses are currently employed for the preparation of fibrinogen and thrombin concentrates. The machines for sequestration and multicomponent collection have been adapted for the concurrent procurement of plasma and platelets. A further level of complexity was introduced by the addition to glues of peripheral, bone marrow and cord-blood-derived stem cells to help or determine tissue regeneration. Instead of more new technologies, larger studies are now needed to quantify the benefits and clarify the optimal application for these products.

Quo vadis haemapheresis. Current developments in haemapheresis

The techniques of haemapheresis originated in the development of centrifugal devices separating cells from plasma and later on plasma from cells. Subsequently membrane filtration was developed allowing for plasma-cell separation. The unspecificity of therapeutic plasma exchange led to the development of secondary plasma separation technologies being specific, semi-selective or selective such as adsorption, filtration or precipitation. In contrast on-line differential separation of cells is still under development. Whereas erythrocytapheresis, granulocytapheresis, lymphocytapheresis and stem cell apheresis are technically advanced, monocytapheresis may need further improvement. Also, indications such as erythrocytapheresis for the treatment of polycythaemia vera or photopheresis though being clinically effective and of considerable importance for an appropriate disease control are to some extent under debate as being either too costly or without sufficient understanding of the mechanism. Other forms of cell therapy are under development. Rheohaemapheresis as the most advanced technology of extracorporeal haemorheotherapy is a rapidly developing approach contributing to the treatment of microcirculatory diseases and tissue repair. Whereas the control of a considerable number of (auto-) antibody mediated diseases is beyond discussion, the indication of apheresis therapy for immune complex mediated diseases is quite often still under debate. Detoxification for artificial liver support advanced considerably during the last years, whereas conclusions on the efficacy of septicaemia treatment are debatable indeed. LDL-apheresis initiated in 1981 as immune apheresis is well established since 24 years, other semi-selective or unspecific procedures, allowing for the elimination of LDL-cholesterol among other plasma components are also being used. Correspondingly Lp(a) apheresis is available as a specific, highly efficient elimination procedure superior to techniques which also eliminate Lp(a). Quality control systems, more economical technologies as for instance by increasing automation, influencing the over-interpretation of evidence based medicine especially in patients with rare diseases without treatment alternative, more insight into the need of controlled clinical trials or alternatively improved diagnostic procedures are among others tools ways to expand the application of haemapheresis so far applied in cardiology, dermatology, haematology, immunology, nephrology, neurology, ophthalmology, otology, paediatrics, rheumatology, surgery and transfusion medicine.

UV-resonance Raman spectroscopic study of human plasma of healthy donors and patients with thrombotic microangiopathy

Various diseases shift the composition of human plasma; hence, the relative quantification of plasma constituents offers the opportunity to use the dynamic and complex composition of plasma to gain information on novel diagnostic and prognostic factors. Since plasma contains, besides water, mostly proteins, UV-resonance Raman spectroscopy (UVRR) seems to be a suitable method for investigating plasma. With this method the signals of aromatic amino acids and proteins are selectively enhanced. In this study an UV-resonance Raman approach was used for the investigation of human plasma of healthy volunteers and patients with thrombotic microangiopathy. For comparison, selected plasma components were analyzed for a more detailed characterization of cryoprecipitates from human plasma.

Autologous stem cells (adipose) and fibrin glue used to treat widespread traumatic calvarial defects: case report

This is a report of a 7-year-old girl suffering from widespread calvarial defects after severe head injury with multifragment calvarial fractures, decompressive craniectomy for refractory intracranial hypertension and replantation of cryopreserved skull fragments. Chronic infection resulted in an unstable skull with marked bony defects. Two years after the initial injury the calvarial defects were repaired. Due to the limited amount of autologous cancellous bone available from the iliac crest, autologous adipose derived stem cells were processed simultaneously and applied to the calvarial defects in a single operative procedure. The stem cells were kept in place using autologous fibrin glue. Mechanical fixation was achieved by two large, resorbable macroporous sheets acting as a soft tissue barrier at the same time. The postoperative course was uneventful and CT-scans showed new bone formation and near complete calvarial continuity three months after the reconstruction.

Fibrin sealant produced by the CryoSealR FS System: product chemistry, material properties and possible preparation in the autologous preoperative setting

BACKGROUND AND OBJECTIVES

The CryoSeal FS has been introduced as an automated device for the production of fibrin sealant from small volumes of plasma. We tested this device and compared the product with commercially available fibrin sealants and with the requirements of the European Pharmacopoeia.

MATERIALS AND METHODS

The CP3 program and disposables required were used to manufacture fibrin sealant. The chemistry and mechanical properties of the product were investigated.

RESULTS

The cryoprecipitate generated with CryoSeal contains concentrated fibrinogen and critical clotting factors. The efficiency of the production process is poor, but the production procedure itself is simple and not time-consuming. The volume of plasma required allows application in the preoperative autologous setting.

CONCLUSIONS

The CryoSeal FS is an automated device for cryoprecipitation and production of thrombin. It can be implemented easily in the clinical routine, although, owing to product specifications, the efficacy of the CryoSeal fibrin sealant requires further clinical trials.

Blood Products for Hemophilia

Hemophilia is an inherited bleeding disorder, which in its severe form is characterized by recurrent hemarthrosis and internal bleeding. In the absence of effective treatment the prognosis is poor, but the development of blood products in the last few decades has transformed the outlook, and patients can now live essentially normal lives. Treatment options vary around the world, with cryoprecipitate still the mainstay of therapy in many developing countries. Many patients were infected with hepatitis and/or HIV through the use of coagulation factor concentrates before the introduction of physical methods of viral inactivation in the mid-1980s. In more affluent countries, the debate in recent years has focused on the relative merits of plasma versus recombinant products. Coagulation factor concentrates are expensive, and cost-benefit and quality-of-life studies will assume an increasing importance in guiding the selection of products. Looking to the future, genetic engineering offers the potential to create coagulation factors with enhanced properties, such as reduced immunogenicity and prolonged half-life. Transgenic animals are a potential source of therapeutic materials. Several trials of gene therapy for hemophilia are already underway.