Mixture Of Fibrin Research Articles

Autologous Collagen-Induced Chondrogenesis Using Fibrin and Atelocollagen Mixture

For articular cartilage defect treatment, many treatment modalities have been developed. We evaluate the cartilage repair potential of an atelocollagen and fibrin mixture transplanted to cartilage defects. A circular, articular cartilage defect 4 mm in diameter was made in the trochlear region in each of 20 New Zealand white rabbits. The 10 rabbits in the control group were kept without treatment and the 10 rabbits in the experimental group underwent injection of atelocollagen mixed with fibrin. At week 12 following surgery the cartilage was observed and histologically compared in both groups. The surface of the newly generated cartilage was very smooth and even, and we also noted that the entire area was completely regenerated in the experimental group. The control group showed incomplete and irregular cartilage formation in the defect. Regarding the histological scoring, comparison of the two groups differed significantly (p < 0.001). Injection of a mixture of atelocollagen and fibrin used to treat articular cartilage defects of the knee appears to be an effective method for cartilage regeneration.

In Vitro Microvessel Growth and Remodeling within a Three-Dimensional Microfluidic Environment

This paper presents in vitro microvascular network formation within 3D gel scaffolds made from different concentrations of type-I collagen, fibrin, or a mixture of collagen and fibrin, using a simple microfluidic platform. Initially, microvascular network formation of human umbilical vein endothelial cells was examined using live time-lapse confocal microscopy every 90 min from 3 h to 12 h after seeding within three different concentrations of collagen gel scaffolds. Among the three conditions of collagen gel scaffolds (2.0 mg/ml, 2.5 mg/ml, and 3.0 mg/ml), the number of skeleton within collagen gel scaffolds was consistently the highest (3.0 mg/ml), followed by those of collagen gel scaffolds (2.5 mg/ml and 2.0 mg/ml). Results demonstrated that concentration of collagen gel scaffolds, which influences matrix stiffness and ligand density, may affect microvascular network formation during the early stages of vasculogenesis. In addition, the maturation of microvascular networks in monoculture under different gel compositions within gel scaffolds (2.5 mg/ml) was examined for 7 d using live confocal microscopy. It was confirmed that pure fibrin gel scaffolds are preferable to collagen gel or collagen/fibrin combinations, significantly reducing matrix retractions during maturation of microvascular networks for 7 d. Finally, early steps in the maturation process of microvascular networks for 14 d were characterized by demonstrating sequential steps of branching, expanding, remodeling, pruning, and clear delineation of lumens within fibrin gel scaffolds. Our findings demonstrate an in vitro model for generating mature microvascular networks within 3D microfluidic fibrin gel scaffolds (2.5 mg/ml), and furthermore suggest the importance of gel concentration and composition in promoting the maturation of microvascular networks.

Bone chips, fibrin glue, and osteogeneration following lateral suboccipital craniectomy: a case report

BackgroundSuboccipital craniectomy is a conventional approach for exploring cerebellopontine angle lesions. A variety of techniques have been successfully employed to reconstruct a craniectomy. This is the first report about the histological findings after performing a cranioplasty by using a mixture of autologous bone chips and human allogenic fibrin glue.Case presentationA 53-year-old German woman underwent left lateral suboccipital retrosigmoidal craniectomy for treatment of trigeminal neuralgia in 2008. Cranioplasty was perfomed by using a mixture of autologous bone chips and human allogenic fibrin glue. Due to recurrent neuralgia, a second left lateral suboccipital craniectomy was performed in 2012. The intraoperative findings revealed a complete ossification of the former craniotomy including widely mature trabecular bone tissue in the histological examination.ConclusionA mixture of autologous bone chips and human allogenic fibrin glue seems to provide sufficient bone-regeneration revealed by histological and neuroradiological examinations.

An Episode of Proliferative Hemorrhagic Enteropathy Associated with Lawsonia Intracellularis in a Pig Farm from Romania

Introduction: In swine, Lawsonia intracellularis is known to be responsible for porcine proliferative enteropathy. The syndrome can be divided in an acute intestinal hemorrhage (proliferative hemorrhagic enteropathy) affecting naive adult pigs and a wasting disease (porcine intestinal adenomatosis) in growing pigs. As new diagnostic techniques develop, there is increased number of pig farms where L. intracellularis is being identified worldwide. Aims: There are few reports of L. intracellularis outbreaks in Romania. We aimed to describe the clinical signs, treatment, outcome, gross necropsy and histopathological lesions from an episode of proliferative hemorrhagic enteropathy associated with L. intracellularis in a farm from Transylvania. Materials and methods: A farm of 4000 pigs (TOPIGS line) from Bistrita-Nasaud County. The microscopical examination was composed of Hematoxilin and Eosin exam, Warthin-Starry silver stain and immunohistochemistry for Multi-Cytokeratin. Results: Over a period of 6 days, a total number of 10 pigs dyed (from 2000 animals in the age group 90-120 days), and 1 pig dyed (from 1000 animals in the age group 60-90 days) with pallor, anorexia or with no clinical signs. Gross lesions were represented by pallor of the carcass and were restricted to the ileum. The intestinal wall was thicker (cerebriform aspect) and turgid. A mixture of blood and fibrin was present in the ileum, impregnating the faeces in the large intestine. Histologically the mucosa was thicker due to epithelial proliferation (Multi-Cytokeratin positive), with few Goblet cells, with severe erosion, necrosis and haemorrhage. Curved rod-shaped bacteria with morphology consistent with L. intracellularis were observed in the apical cytoplasm of epithelial cells using the Warthin-Starry silver stain. The food was medicated with chlortetracycline (20 - 40 mg a.s./kg b.w./day) and the pigs remained healthy, with no further mortality. Conclusion: We report here an outbreak of proliferative hemorrhagic enteropathy associated with L. intracellularis in a pig farm from Romania, emphasizing the importance of early diagnostic and control measures for this disease.

Sinus Augmentation With Platelet-Rich Fibrin in Combination With Bovine Bone Graft Versus Bovine Bone Graft in Combination With Collagen Membrane

The purpose of this study was to compare the efficacy between the use of bovine bone graft material and platelet-rich fibrin (PRF) mixture (test group) and bovine bone graft material and collagen membrane combination (control group) in 2-stage maxillary sinus augmentation. According to specific inclusion/exclusion criteria, patients treated between 2008 and 2012 were selected. Panoramic radiographs were used for radiologic assessments. To evaluate the relationship between sinus-graft height and each implant, the bone level (BL) was divided by implant length (IL). To evaluate the change in the height of grafted sinus, the grafted sinus floor above the lowest part of the original sinus height (GSH) was divided by the original sinus height (OSH). Samples taken during implant surgery were used for histologic and histomorphometric analyses. Twenty-five patients, 32 augmentation surgeries, and 66 one-stage implants were included in the study. No implant loss or complication was observed in either group. There were no statistical differences according to new bone formation (P = .61) and biomaterial remnant (P = .87). During the evaluation period, the test group showed statistically less change in the BL/IL ratio (P = .022). The difference of GSH/OSH ratio was found to be insignificant between groups (P = .093). It was observed that the grafted sinus covering the implant apex and sinus floor was above the original sinus height in both groups. It may be concluded from this study that both combinations can be successfully used for sinus augmentation. Further studies evaluating different graft materials and PRF combinations in the early phases of healing would be beneficial.

Novel repair technique for articular cartilage defect using a fibrin and hyaluronic acid mixture

We evaluated the cartilage repair potential of a hyaluronic acid and fibrin mixture when transplanted into cartilage defects. Circular, articular, cartilage defects 4-mm in diameter were made in the trochlear region in 21 New Zealand white rabbits divided into three groups. The seven rabbits in the control group underwent microfracture (M group), the seven rabbits in the experimental group underwent microfracture with subsequent injection of hyaluronic acid mixed with fibrin (MH group), and seven rabbits in the other experimental group underwent microfracture followed by injection of bone marrow concentrate and hyaluronic acid mixed with fibrin (MBH group). At week 12 following surgery, the cartilage was observed and histologically compared in the three groups. The surface of the newly generated cartilage was very smooth and even, and we noticed that the entire area was completely regenerated in both experimental groups. The control group showed incomplete and irregular cartilage formation in the defect. In histologic scoring, comparison of the MBH group (M= 2.333) and the M group (M= 9.000) differed significantly (P= 0.046). Therefore, injection of a mixture of bone marrow concentrate, hyaluronic acid and fibrin to treat articular cartilage defects of the knee appears to be an effective method of cartilage regeneration.

Marantic endocarditis – A not so benign entity

Marantic, verrucous or nonbacterial thrombotic endocarditis, is characterised by the deposition of an amorphous mixture of fibrin and platelets onto heart valves. Although not commonly a cause of death in forensic practice, it may be associated with systemic embolisation. This was observed in a 60-year-old woman who suddenly collapsed and was found at autopsy to have a poorly differentiated adenocarcinoma of the lung with vegetations from marantic endocarditis on the mitral valve and embolisation with infarcts in the left kidney, the spleen, the right occipital cortex of the brain and the left ventricle of the heart. Death was due to coronary artery embolism from marantic endocarditis associated with an undiagnosed adenocarcinoma of the lung. Although marantic endocarditis is more common in hospital autopsies than in forensic cases, it can have lethal complications that result in sudden and unexpected death. Histories of debilitating disease and/or arterial thromboembolic episodes necessitate meticulous examination of the cardiac valves with careful serial sectioning of the major epicardial coronary arteries and histologic sampling of both ventricles.

Abstract 16766: A Human Induced Pluripotent Stem Cell-Derived Engineered Cardiac Tissue Model of Pompe Disease

Background: Infantile-onset Pompe disease is a lethal autosomal recessive lysosomal storage disorder caused by the complete loss of acid α-glucosidase activity resulting in glycogen accumulation within lysosomes. Skeletal and cardiac muscle pathology develop due to aberrant glycogen metabolism and lysosomal dysfunction. This work presents the first in vitro human cardiac tissue model of Pompe disease documenting the classic Pompe cellular phenotype within a multicellular engineered cardiac tissue preparation. Methods: Pompe disease-specific human induced pluripotent stem (iPS) cell derived cardiomyocyte (iPS-CMs) were seeded into a polymerizing fibrin mixture to form mechanically integrated multicellular engineered cardiac tissue (ECT) constructs that were evaluated over a one-month period in parallel with healthy human iPS cell derived ECTs. Weekly measurements of isometric force and intracellular calcium transients were recorded under varying work load imposed by electrical pacing and β1 adrenergic stimulation. Structural assessment was performed using electron microscopy and immunohistochemistry. Results: Healthy and Pompe iPS-CMs can form cylindrically shaped ECTs of 1-2 mm diameter and 1.5-2 cm in length composed of coupled CMs that generate force in the milli-newton range along the cylindrical axis. We report structural changes in the ECT model consistent with the hallmarks of Pompe disease including progressive intracellular glycogen accumulation, lysosomal disruption, and myofibrillar disarray. Both healthy and Pompe ECTs generate higher twitch forces in response to mechanical stretch, have a negative force-frequency relationship characteristic of immature myocardium, and have an inotropic response to dobutamine stimulation. Conclusion: Human iPS-CM ECTs obey the Frank-Starling law and produce calcium cycling and force kinetics that respond to β1 adrenergic stimulation. The Pompe ECT provides a novel cardiac tool in which to further study the pathophysiology of this disease and test novel therapeutic approaches.

A Method for Ovarian Follicle Encapsulation and Culture in a Proteolytically Degradable 3 Dimensional System

The ovarian follicle is the functional unit of the ovary that secretes sex hormones and supports oocyte maturation. In vitro follicle techniques provide a tool to model follicle development in order to investigate basic biology, and are further being developed as a technique to preserve fertility in the clinic. Our in vitro culture system employs hydrogels in order to mimic the native ovarian environment by maintaining the 3D follicular architecture, cell-cell interactions and paracrine signaling that direct follicle development. Previously, follicles were successfully cultured in alginate, an inert algae-derived polysaccharide that undergoes gelation with calcium ions. Alginate hydrogels formed at a concentration of 0.25% w/v were the most permissive for follicle culture, and retained the highest developmental competence. Alginate hydrogels are not degradable, thus an increase in the follicle diameter results in a compressive force on the follicle that can impact follicle growth. We subsequently developed a culture system based on a fibrin-alginate interpenetrating network (FA-IPN), in which a mixture of fibrin and alginate are gelled simultaneously. This combination provides a dynamic mechanical environment because both components contribute to matrix rigidity initially; however, proteases secreted by the growing follicle degrade fibrin in the matrix leaving only alginate to provide support. With the IPN, the alginate content can be reduced below 0.25%, which is not possible with alginate alone. Thus, as the follicle expands, it will experience a reduced compressive force due to the reduced solids content. Herein, we describe an encapsulation method and an in vitro culture system for ovarian follicles within a FA-IPN. The dynamic mechanical environment mimics the natural ovarian environment in which small follicles reside in a rigid cortex and move to a more permissive medulla as they increase in size. The degradable component may be particularly critical for clinical translation in order to support the greater than 10(6)-fold increase in volume that human follicles normally undergo in vivo .

Enhanced skin wound healing by a sustained release of growth factors contained in platelet-rich plasma

Platelet-rich plasma (PRP) contains growth factors that promote tissue regeneration. Previously, we showed that heparin-conjugated fibrin (HCF) exerts the sustained release of growth factors with affinity for heparin. Here, we hypothesize that treatment of skin wound with a mixture of PRP and HCF exerts sustained release of several growth factors contained in PRP and promotes skin wound healing. The release of fibroblast growth factor 2, platelet-derived growth factor-BB, and vascular endothelial growth factor contained in PRP from HCF was sustained for a longer period than those from PRP, calcium-activated PRP (C-PRP), or a mixture of fibrin and PRP (F-PRP). Treatment of full-thickness skin wounds in mice with HCF-PRP resulted in much faster wound closure as well as dermal and epidermal regeneration at day 12 compared to treatment with either C-PRP or F-PRP. Enhanced skin regeneration observed in HCF-PRP group may have been at least partially due to enhanced angiogenesis in the wound beds. Therefore, this method could be useful for skin wound treatment.

Effect of stem cells and fibrin concentration on the vascularization of the Medpor orbital implant

To determine the effect of adipose-derived adult stem cells (ADASCs) and optimal concentration of fibrin on fibrovascular ingrowth into porous polyethylene orbital implants (Medpor). Medpor sheet treated with O.25% fibrin only and ADASCs in mixtures containing fibrin (0.25%, 0.5% or 1.25%) were applied to a Medpor sheet and implanted in the back of each of 20 athymic nude mice. After 10 days, implants were removed and observed for fibrovascularization and stability. Haemoglobin, collagen and cellular DNA content were determined in quantitative assays. Haemoglobin, collagen and cellular DNA levels were significantly higher in ADASC group than in the cell-free implant (0.25% fibrin only) group (P < 0.01). The level of haemoglobin and collagen content was significantly higher in the ADASC + 0.5% fibrin group among the ADASC and fibrin mixtures (P < 0.01). ADASCs significantly improved fibrovascularization on Medpor compared with implants alone. Fibrin, used together with ADASCs to potentiate fibrovascularization, was most effective at concentrations of 0.5%.

Fibrin/Hyaluronic Acid Composite Hydrogels as Appropriate Scaffolds for In Vivo Artificial Cartilage Implantation

Hydrogels prepared from a mixture of fibrin and high-molecular weight (MW) hyaluronic acid (HA) were found to be suitable scaffolds for chondrocyte seeding and pig knee cartilage regeneration. Collagen in the hydrogels is not necessary for the formation of biomechanically stable tissue. Regenerated cartilage showed very good biomechanical and histological properties only 6 months after implantation. Notably, the quality of the healing process was dependent on the initial chondrocyte concentration of the scaffolds. These experiments were performed according to good laboratory practice (GLP).

Surface modification with fibrin/hyaluronic acid hydrogel on solid-free form-based scaffolds followed by BMP-2 loading to enhance bone regeneration

Bone tissue engineering often requires a well-defined scaffold that is highly porous. The multi-head deposition system (MHDS), a form of solid freeform fabrication, has raised great interest as a method for fabricating scaffolds, since it yields a highly porous inter-connective structure without the use of cytotoxic solvents, and permits the diffusion of nutrients and oxygen. However, this method is not suitable for introducing proteins, as it includes a heating process. Hydrogels incorporated with protein coating of the scaffold surface could overcome this MHDS limitation. In the present study, the surface of a scaffold fabricated using MHDS was coated with a mixture of fibrin and hyaluronic acid (HA) and used as a vehicle for delivery of both bone morphogenetic protein-2 (BMP-2) and adipose-derived stromal cells (ASCs). Fibrin/HA coating of the scaffold significantly enhanced initial cell attachment. Furthermore, the in vitro release of BMP-2 from fibrin/HA-coated scaffolds was sustained for 3 days and it stimulated the alkaline phosphatase activity of ASCs seeded on the scaffold for 10 days more actively and continuously than did the soluble BMP-2 that was added to the culture media, not the scaffold itself. Importantly, the transplantation of undifferentiated ASCs inoculated on BMP-2-loaded, fibrin/HA-coated scaffolds resulted in more improved bone formation and mineralization than did the transplantation of undifferentiated ASCs seeded on uncoated scaffolds or on fibrin/HA-coated scaffolds without BMP-2, but containing BMP-2 in the cell suspension medium. These results show that BMP-2-loaded, fibrin/HA-coated scaffolds fabricated using MHDS may be useful in stimulating bone regeneration from undifferentiated ASCs in vivo.

Chronic, otogenic, epidural pneumatocoele with delayed mass effect: case report

Mastoid hyperpneumatisation predisposes to intracranial pneumatocoele development, due to the risk of rupture of the thin, bony walls. Intracranial pneumatocoele may be precipitated by even minor head trauma or an abrupt change in middle-ear pressure, with the potential risk of infectious or compressive intracranial complications. A 19-year-old man with mastoid hyperpneumatisation developed a chronic intracranial-epidural pneumatocoele of traumatic origin in the right parieto-occipital area, in contiguity with the posterior mastoid cells. Eighteen months later, after a common cold, the patient developed signs of intracranial hypertension, due to the pneumatocoele spreading to the right epidural anterior fossa. A large right mastoidectomy extended to the retrosigmoid cells was performed, and a watertight seal applied over a large retrosigmoid cell using bovine pericardium and a mixture of bone powder and fibrin glue. The patient was discharged on post-operative day three with no symptoms. Ten days after surgery, computed tomography monitoring showed complete reabsorption of the pneumatocoele. In cases of chronic, otogenic, epidural pneumatocoele, the possibility of the sudden onset of serious complications suggests the need for early repair of the communication between the temporal bone and the intracranial compartments. Closure of the fistula using autogenic and/or allogenic materials is usually adequate to resolve the pneumatocoele.

Factor VIII contributes to platelet-fibrin thrombus formation via thrombin generation under low shear conditions

Introduction Thrombus growth under low blood flow velocity plays an important role in the development of deep venous thrombosis (DVT). Increased plasma levels and activities of coagulation factor VIII (FVIII) comprise risk factors for DVT and pulmonary thromboembolism. Objective To localize FVIII in human venous thrombi of DVT and to determine whether FVIII contributes to thrombus formation under low shear conditions. Methods The localization of FVIII in venous thrombi obtained from patients with DVT was examined by immunohistochemistry. The role of FVIII in thrombus formation was investigated using a flow chamber system. Venous blood from healthy volunteers were incubated with an anti-FVIII monoclonal antibody (VIII-3776) or non-immunized mouse IgG 1. Blood samples were perfused on immobilized type III collagen at wall shear rates of 70/s and 400/s and then the surface area covered by platelets and fibrin was morphometrically evaluated. Prothrombin fragment 1+2 (PF1+2) generation was measured before and after perfusion. Results Venous thrombi of DVT comprised a mixture of platelets, fibrin and erythrocytes. Factor VIII appeared to be colocalized with glycoprotein IIb/IIIa, fibrin and von Willebrand factor in the thrombi. VIII-3776 specifically recognized the light chain of FVIII and prolonged the activated partial thromboplastin time (aPTT), but not prothrombin time (PT). The antibody significantly reduced platelets and fibrin covering, as well as PF1+2 generation at wall shear rates of 70/s and 400/s. Conclusions These results suggest that FVIII contributes to platelet aggregation and fibrin formation via thrombin generation under low shear conditions.

2D and 3D collagen and fibrin biopolymers promote specific ECM and integrin gene expression by vascular smooth muscle cells

Collagen Type I and fibrin are polymeric proteins commonly used in the field of regenerative medicine as the foundational matrix of engineered tissues. We examined the response of vascular smooth muscle cells (VSMC) to both two-dimensional (2D) substrates as well as three-dimensional (3D) matrices of these biopolymers. Pure collagen Type I, pure fibrin and composite matrices consisting of 1:1 mixtures of collagen and fibrin were studied. Relative gene expression of three ECM molecules (collagen Type I and III, and tropoelastin) and three integrin subunits (integrins α1, β1 and β3) was determined over 7 days in culture using quantitative RT-PCR. Expression of all of these marker genes was up-regulated in 3D matrices, relative to 2D substrates. Tropoelastin, integrin α1 and integrin β1 were highest in collagen matrices, while collagen III and integrin β3 expression were highest in pure fibrin, and collagen I expression was highest in the collagen–fibrin composite materials. Both the compositional and temporal expression patterns of these specific ECM-related genes were suggestive of a wound healing response. These results illuminate the short-term responses of VSMC to 2D and 3D biopolymer matrices, and have relevance to tissue engineering and cardiovascular biology.

Engineered blood and lymphatic capillaries in 3‐D VEGF‐fibrin‐collagen matrices with interstitial flow

In vitro endothelial cell organization into capillaries is a long standing challenge of tissue engineering. We recently showed the utility of low level interstitial flow in guiding the organization of endothelial cells through a 3-D fibrin matrix-containing covalently bound vascular endothelial growth factor (VEGF). Here this synergistic phenomenon was extended to explore the effects of matrix composition on in vitro capillary morphogenesis of human blood versus lymphatic endothelial cells (BECs and LECs). Different mixtures of fibrin and collagen were used in conjunction with constant concentrations of matrix-bound VEGF and slow interstitial flow over 10 days. Interestingly, the BECs and LECs each showed a distinct preference in terms of organization for matrix composition: LECs organized the most extensively in a fibrin-only matrix, while BEC organization was optimized in the compliant collagen-containing matrices. Furthermore, the BECs and LECs produced architecturally different structures; while BECs organized in thick, branched networks containing wide lumen, the LECs were elongated into slender, overlapping networks with fine lumen. These data demonstrate the importance of the 3-D matrix composition in facilitating and coordinating BEC and LEC capillary morphogenesis, which is important for in vitro vascularization of engineered tissues.

Tissue reactions induced by different embolising agents in cerebral arteriovenous malformations: a histopathological follow-up

Comparative histopathological analysis was performed in 47 incompletely embolised and resected cerebral arteriovenous malformations (AVMs). Thirty-three AVMs were embolised with n-butyl-cyanoacrylate (NBCA), four with iso-butyl-cyanoacrylate (IBCA), seven with polyvinyl alcohol particles (PVA), one with a fibrin mixture, one with silicon pellets, and one with microcatheter balloons. Maximum exposure time (MET) of the embolising agent (interval between embolisation and surgery) ranged from <24 hours to 80 months. All AVMs were investigated regarding angionecrosis, angiofibrosis, acute inflammation, chronic inflammation, foreign-body reactions, vascular calcification, blood admixture to embolising cast, and capillary recanalisation within the AVMs. These parameters were correlated with MET, comparing different embolising agents, age, and sex. A typical sequence of events depending on MET is observed in all embolised AVMs: acute inflammation with mural angionecrosis is soon replaced by prominent chronic granulomatous vasculitis, which remains stable and is detectable for a very long time, even in AVMs with a MET of more than 6 years. Capillary recanalisation is always present in incompletely embolised AVMs, detectable after 3 months of MET, irrespective of the embolising agent used. Age and sex does not influence pattern and time course of tissue lesions and recanalisation in incompletely embolised AVMs.

Effect of antibiotics in fibrin sealant on healing colonic anastomoses in the rat

In 90 rats a colonic anastomosis was constructed with 12 interrupted 7/0 polypropylene sutures. Group 1 (n = 30) served as a control group. In group 2 (n = 30) the anastomosis was sealed with fibrin adhesive and in group 3 (n = 30) a mixture of fibrin, clindamycin and cefotaxime was used. On days 2, 4 and 7, ten animals in each group were killed. Adhesion formation was significantly increased in groups 2 and 3 compared with the control group. On day 2 the anastomosis was significantly stronger after sealing with antibiotic-fibrin mixture. On day 4 the bursting pressure in group 2 was significantly lower than in groups 1 and 3. At the same time the concentration of hydroxyproline was significantly reduced in group 2, but not in group 3. The addition of antibiotics prevents the negative effect of fibrin adhesive on the healing colonic anastomosis and contributes to a stronger anastomosis on day 2 after operation.

Characterization of cortical neuron outgrowth in two‐ and three‐dimensional culture systems

To improve the ability of regeneration by grafting living cells or by adding growth factor to a lesion site, it is important to find good biomaterials for neuron survival and regeneration. This study focused on two- and three-dimensional cultures in a matrix using biomaterials such as agarose, collagen, fibrin, and their mixtures, because these are considered to be suitable biomaterials for neuron outgrowth. Cortical neurons were dissected from E17 rat embryos and cultured in agarose gel, collagen gel, fibrin glue, and mixtures of collagen and fibrin. Results showed that neurons cultured in collagen gel and fibrin glue had longer periods of survival (more than 3 weeks) and better neurite extension than those observed in agarose gels. As to the survival rate according to the MTT and lactate dehydrogenase assays, fibrin glue was the most suitable biomaterial for neuron survival among the biomaterials examined. With two-dimensional fibrin plating, neuron cells exhibited cell aggregation and stress fibers, but the same results were not observed with collagen gel. There were no differences in neurite extension and survival in the mixtures of collagen and fibrin. The results suggest that collagen and fibrin can provide a suitable substrate for a three-dimensional culture matrix for neuronal survival and differentiation.