Biomaterial Database

Collagen-hydroxyapatite composites with applications as bone substitutes: synthesis and characterisation. 2009

Petruţa Flocea, and M Popa, and Fl Munteanu, and Liliana Vereştiuc

Technical University Gh. Asachi Iaşi, School of Chemical Engineering and Environmental Protection, Department of Chemical Engineering.

The paper presents synthesis, swelling properties and in vitro degradation tests of collagen-hydroxyapatite composites, in the order to obtain new bone substitutes. Also, by using a 3D analysis with finite element the tension distribution at bone--synthesised substitute interface and in bone by comparing to bone substitute was determined. METHODS Collagen type I from tendon bovine source, provided from Sigma-Aldrich, has been used for materials synthesis. Composite materials have been obtained by hydroxyapatite (HA) precipitation from its precursors (aqueous solutions of CaCl2 and NaH2PO4), in the presence of NH4OH and process finalising at 37 degrees C. Three types of materials have been prepared: 75% collagen--25% HA(w/w)--Coll75-HA; 50% collagen--50% HA(w/w)--Coll50-HA; 25% collagen--75% HA(w/ w)--Coll25-HA. Swelling properties of the composite materials were evaluated gravimetrically and in vitro degradation in buffered collagenase was studied. The elasticity modulus was calculated from the dependence force versus material's strain. The 3D analysis with finite element at bone--synthesised substitute interface was performed for a right osteosynthesised fracture from femur. CONCLUSIONS Materials swelling in simulated body fluids revealed higher equilibrium swelling degree for HA-collagen composites with increased content of collagen. Materials are degraded by collagenase, the degradation rate being strongly dependent by composition; a higher content of collagen makes the composites more sensitive to the specific enzyme. SEM data have shown the forming of hydroxyapatite crystals onto collagen fibers. The mechanical characterisation has shown a limited elasticity at an increased value of the applied force for Coll25-HA. Over these forces the plasticity was observed. By using the 3D analysis with finite element at bone--synthesised substitute interface a higher strength was determined in the bone by comparison to bone substitute. CONCLUSIONS The superior elasticity properties of the synthesised collagen-HA by comparison to physiological biomechanical limits indicate a good behaviour as resistance bone substitute with applications in the extensive bones reconstruction (endoprosthesis revision, bone infections etc.).

UI	MeSH Term	Description	Entries
D008422	Materials Testing	The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.	Biocompatibility Testing,Biocompatible Materials Testing,Hemocompatibility Testing,Testing, Biocompatible Materials,Testing, Hemocompatible Materials,Hemocompatibility Testings,Hemocompatible Materials Testing,Materials Testing, Biocompatible,Materials Testing, Hemocompatible,Testing, Biocompatibility,Testing, Hemocompatibility,Testing, Materials,Testings, Biocompatibility
D008432	Mathematical Computing	Computer-assisted interpretation and analysis of various mathematical functions related to a particular problem.	Statistical Computing,Computing, Statistical,Mathematic Computing,Statistical Programs, Computer Based,Computing, Mathematic,Computing, Mathematical,Computings, Mathematic,Computings, Mathematical,Computings, Statistical,Mathematic Computings,Mathematical Computings,Statistical Computings
D008953	Models, Anatomic	Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.	Anatomic Models,Models, Surgical,Moulages,Models, Anatomical,Anatomic Model,Anatomical Model,Anatomical Models,Model, Anatomic,Model, Anatomical,Model, Surgical,Moulage,Surgical Model,Surgical Models
D001842	Bone and Bones	A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principal cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.	Bone Tissue,Bone and Bone,Bone,Bones,Bones and Bone,Bones and Bone Tissue,Bony Apophyses,Bony Apophysis,Condyle,Apophyses, Bony,Apophysis, Bony,Bone Tissues,Condyles,Tissue, Bone,Tissues, Bone
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D003094	Collagen	A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).	Avicon,Avitene,Collagen Felt,Collagen Fleece,Collagenfleece,Collastat,Dermodress,Microfibril Collagen Hemostat,Pangen,Zyderm,alpha-Collagen,Collagen Hemostat, Microfibril,alpha Collagen
D005264	Femoral Fractures	Fractures of the femur.	Femoral Fracture,Fracture, Femoral,Fractures, Femoral
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001672	Biocompatible Materials	Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.	Biomaterials,Bioartificial Materials,Hemocompatible Materials,Bioartificial Material,Biocompatible Material,Biomaterial,Hemocompatible Material,Material, Bioartificial,Material, Biocompatible,Material, Hemocompatible