Influence of calcium chloride and aprotinin in the in vivo biological performance of a composite combining biphasic calcium phosphate granules and fibrin sealant.
ABSTRACT Highly bioactive biomaterials have been developed to replace bone grafts in orthopedic revision and maxillofacial surgery for bone augmentation. A mouldable, self-hardening material can be obtained by combining TricOs Biphasic Calcium Phosphate Granules and Tissucol Fibrin Sealant. Two components, calcium chloride and antifibrinolytic agents (aprotinin), are essential for the stability of the fibrin clot. The ingrowth of cells in composites combining sealants without calcium chloride or with a low concentration of aprotinin was evaluated in vivo in an experiment on rabbits. Bone colonization was compared using TricOs alone or with the composite made from TricOs and the standard fibrin sealant. Without the addition of calcium chloride, the calcium ions released by the ceramic component interacted with the components of the sealant too late to stabilize the clot. With a low concentration of aprotinin, the degradation of the clot occurred more quickly, leading to the absence of a scaffold on which the bone cells could colonize the composite. Our results indicate that a stable fibrin scaffold is crucial for bone colonization. The low calcium chloride and low aprotinin groups have shown lower bone growth. Further studies will be necessary to determine the minimal amount of antifibrinolytic agent (aprotinin) necessary to allow the same level of osteogenic activity as the TricOs-fibrin glue composite.
SourceAvailable from: Mark Ahearne[Show abstract] [Hide abstract]
ABSTRACT: The limited intrinsic repair capacity of articular cartilage has led to the investigation of different treatment options to promote its regeneration. The delivery of hydrogels containing stem or progenitor cells and growth factor releasing microspheres represents an attractive approach to cartilage repair. In this study, the influence of the encapsulating hydrogel on the ability of progenitor cells coupled with TGF-β3 releasing microspheres to form cartilaginous tissue was investigated. Fibrin, agarose and gellan gum hydrogels containing TGF-β3 loaded gelatin microspheres and progenitor cells derived from the infrapatellar fat-pad of the knee were cultured for 21 days in a chemically defined media. In the presence of TGF-β3 releasing microspheres, gellan gum hydrogels were observed to facilitate greater cell proliferation than fibrin or agarose hydrogels. Histological and biochemical analysis of the hydrogels indicated that fibrin was the least chondro-inductive of the three hydrogels, while agarose and gellan gum appeared to support more robust cartilage formation as demonstrated by greater sGAG accumulation within these constructs. Gellan gum hydrogels also stained more intensely for collagen type II and collagen type I, suggesting that although total collagen synthesis was higher in these constructs, that the phenotype may be more fibrocartilaginous in nature than normal hyaline cartilage. This study demonstrates how the encapsulating hydrogel can have a significant impact on the ability of stem cells to form cartilage when incorporated into a growth factor delivery system.Biomedical Materials 03/2013; 8(3):035004. DOI:10.1088/1748-6041/8/3/035004 · 2.92 Impact Factor
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ABSTRACT: In tissue engineering techniques, three-dimensional scaffolds are needed to adjust and guide cell growth and to allow tissue regeneration. The scaffold must be biocompatible, biodegradable and must benefit the interactions between cells and biomaterial. Some natural biomaterials such as fibrin provide a structure similar to the native extracellular matrix containing the cells. Fibrin was first used as a sealant based on pools of commercial fibrinogen. However, the high risk of viral transmission of these pools led to the development of techniques of viral inactivation and elimination and the use of autologous fibrins. In recent decades, fibrin has been used as a release system and three-dimensional scaffold for cell culture. Fibrin scaffolds have been widely used for the culture of different types of cells, and have found several applications in tissue engineering. The structure and development of scaffolds is a key point for cell culture because scaffolds of autologous fibrin offer an important alternative due to their low fibrinogen concentrations, which are more suitable for cell growth. With this review our aim is to follow methods of development, analyze the commercial and autologous fibrins available and assess the possible applications of cell culture in tissue engineering in these three-dimensional structures.Experimental Cell Research 12/2013; DOI:10.1016/j.yexcr.2013.12.017 · 3.37 Impact Factor
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ABSTRACT: Abstract Aim of the study: To develop a clinical grade fibrin gel for the culture of oral mucosal epithelial cells (OMEC) intended for ocular surface reconstruction in the treatment of limbal stem cell deficiency (LSCD). Materials and methods: Transparent fibrin gels composed of fibrinogen and thrombin were developed for the culture of epithelial cells. Oral mucosa was harvested from the buccal region of healthy volunteers and cultured as explants on fibrin gels. Tranexamic acid (TA), a clinically approved anti-fibrinolytic agent was added to prevent the fibrin gel from digesting due to cellular activity. The gels were stained for p63α (as a marker of poorly differentiated epithelial cells), CK19, CK13 and CK3 (expressed by OMEC). Epithelial cell stratification was observed using hematoxylin-eosin staining. Results: Addition of TA prevented gels from dissolving during the culture period. OMEC proliferated on the fibrin gel and attained confluence over a 2-week period (±2 d) and exhibited a typical epithelial, cobblestone morphology. Basal OMEC exhibited positive staining for p63α while the superficial cells exhibited positive staining for CK3. The cells expressed a strong immunoreactivity for CK19 and CK13 suggesting that they retained a normal oral epithelial phenotype. Conclusion: Fibrin gels, maintained in the presence of TA, to control the rate of substrate degradation, provide a more robust yet transparent substrate for the culture and transplantation of cultured OMEC. The fibrin gels are easily standardized, the components commercially available, and produced from clinically approved materials. The resulting stratified OMEC-derived epithelium displays characteristics similar to that of a human cornea, e.g. CK3 expression. The conventional dependence on a murine feeder layer for support of epithelial cells is unnecessary with this technique and hence, provides for an attractive alternative for treatment of LSCD.Current Eye Research 11/2014; DOI:10.3109/02713683.2014.978477 · 1.66 Impact Factor