摘要:@@ Skin is composed of both a dermal layer-consisting primarily of fibroblasts,and matrix macromolecules (ECM)-and an epidermal layer-composing of epidermal cells containing keratin filaments undergoing progressive differentiation from abasal proliferating layer to a surface consisting of terminally differentiated, epidermal cells that protect the skin from the environment.
摘要:@@ Since the invention of Ruby laser by Maiman in 1960s, many kinds of lasers areused widely in dentistry. It has been proved that laser irradiation can produce acidetching like surface, thus strengthen the bond of material to enamel. But the heatgenerated during irradiation produces damage on dental pulp, which limits the laserapplications on dental hard surfaces.
摘要:@@ FUNCTIONS OF CELLS SCAFFOLD IN THE TISSUE ENGINEERINGCell, cells scaffold and the construction of tissue and organ are three main factors for the Tissue Engineering. A main function of cells scaffold in tissue engineering is to provide an environment for cells propagation.
摘要:@@ Recently, many researches on the repair of peripheral nerve by the aid of nerveregeneration conduit method were carried out and good progresses were attained. Itwas believed that the conduit should be made from biodegradable biomaterial.
摘要:@@ It is a complex and difficult task to simulate the degradating process of porous biologic ceramic in life-form by computer. Because the evolvement of crystal' s structure deals with not only the mechanism of many factors, such as crystallography tropism, the reciprocity of wafer, interfacial movement, but also topology geometry mechanism of dimensional padding.
摘要:@@ The biodegradable polymers have been of great scientific and technological interest in biomedical applications such as surgical repair materials, tissue engineering scaffolds and drug delivery carriers. The most important requirements for synthetic biodegradable polymers are the presence of not only a predictable biodegradable profile and suitable mechnical properties, but also the compatibility with blood and tissues.
摘要:@@ INTRODUCTIONrnIn recent years, many efforts have been made towards the development of new bone substitute materials. Among these, hydroxyapatite / absorbable polymer composites have attracted much attention since such composites may have bone bonding ability due to the presence of hydroxyapatite (HA).
摘要:@@ INTRODUCITIONrnHydroxyapatite (Ca10 (PO4) 6 (OH)2, HA) is a material with biological activity, which has good biocompatibility and is the major mineral constituent of vertebrate hard tissues, such as bone, tooth and some ectopic calcification. As an implanting material, it can induce the growth of new bone, and supply supporting frame for new bone.
摘要:@@ INTRODUCTIONrnHydroxyapatite (HA) biocoatings can form osseointegration at a shorter time than metallic implants, and plasma sprayed (PS) HA coating has received the widest studies and is now used clinically. However, due to the high temperature of plasma flame, soluble impurity phases and amorphous calcium phosphate were contained which declined the bonding strength of the coating, and spoiled the excellent biological properties of HA.
摘要:@@ One of the challenges in the field of tissue engineering is the development of biomaterial/cell interactions. For this purpose, the use of biological materials in tissue engineering requires the application of different chemical or physical procedures for surface modification in order to improve the cell affinity of biomaterials. We have studied the effects of one chemical treatment and one physical treatment: 1-(3-dimethylaminopropyl )-3-ethylcarbodiimide (WSC) and entrapment.
摘要:@@ This study examines the effects of xenografts of microencapsulated bovine chromaffin cells (BCCs) on the rotational behavior of hemiparkinsonian monkey recipients. In addition, it determines the content of monoamine neurotransmitters and their major metabolites in the neostriatum in hemiparkinsonian monkeys. The hemiparkinsonian model in monkeys was induced by a unilateral intracarotid injection of methyl-phenyl-tetrahydropyridine (MPTP). Unencapsulated BCCs (n = 2), BCCs microencapsulated (n= 6) in alginate-polylysine-alginate (APA) membranes as well as empty microencapsules (n = 1) were grafted into the neostriatum of the hemiparkinsonian monkeys.
摘要:@@ INTRODUCTIONrnCalcium phosphate cements (CPC) overcome the practical disadvantages of blocks or granulesl can be handled as a paste and sit in situ. Their structure and composition close to that of HAP make them biocompatible materials. 2 The conventional calcium phosphate cement had some problems such as long setting time (30~60 min) and low compressive strength, etc. In our system, an α-TCP/TTCP powder mixture was mixed with water containing citric acid to control the setting time and compressive strength. In this paper, the effects of various concentration citric acid solutions on the properties of the cement are reported.
摘要:@@ INTRODUCTIONrnThe common construction method of tissue engineered articular cartilage is to isolate and culture chondrocytes,transplant them into the degradable scaffold materials, then to repair the defect of articular cartilage. We designed this experiment to investigate the feasibility of tissue engineered articular cartilage constructed by the technique of centrifuge tube culture without scaffold materials.
摘要:@@ OBJECTIVErnTo investigate the effects of four different materials as carriers of bone morphogenetic protein (BMP) to repair long bone defect.rnMETHODSrn12 mm radius bone defects were made. They were divided into 4 groups in random and repaired respectively with the vascular muscle flap combined with FS/BMP (group A), vascular muscle flap/BMP (group B), bloodless muscle flap/BMP (group C) and autolyzed antigen-extracted allogeneic bone (AAA)/BMP (group D).Their abilities of bone forming to repair bone defects were observed.
摘要:@@ To prepare biomimic bone materials, some thick meshes of demineralized bone matrix (DBM), which are the interest work of collagen fibrils, have been prepared in normal way, and calcium phosphate of nanometeric apatite-li.ke was introduced into these mesh works with aqueous calcium and phosphate salt solution by means of the electrochemical technique at room temperature.
摘要:@@ INTRODUCTIONrnHydroxyapatite (HA) has many biological benefits, such as direct bonding to bone and enhances new bone formation around it. It has been demonstrated that dental and orthopaedic implants coated with HA show superior histological results to the uncoated ones. Various methods as well as plasma spraying, which is commonly used, have been developed to coat HA on metals. However, Plasma-sprayed HA coatings are limited by specific drawbacks such as low crystallinity, weak bond strength to the substrate.
摘要:@@ INTRODUCTIONrnSince the discovery of Bioglass by Hench et al. in 1969, various kinds of glass and glass-ceramic have been found to bond to living bone. All those bioglass and glass-ceramic including CaO-SiO2 components contributed to the bioactivity of those materials. The polymorphism of dicalcium silicate (Ca2SiO4) has been well studied because of the considerable importance of this compound in the cement and refractories industries. Dicalcium silicate may be bioactive in human body because it is also composed of CaO-SiO2 components.
摘要:@@ Artificial joints and tooth roots are the implants with a large number of clinical requirement. The most of current products used in clinic are made from bioinert metallic materials. The main problem exiting in these materials is that there is not a bioactive bonding between the implants and adjacent bone tissues, which will results in loosing and sinking of the implants.
摘要:@@ Fluormica glass-ceramics are widely used in dental field because of their high esthetics, excellent biocompatibility, and good mechanical properties and machinability. The main crystalline phase in fluormica glass-ceramics is either fluorophlogopite or fluorosilicic mica. Dicor(r) is the most notable commercialized fluorsilicic mica glass-ceramics.
摘要:@@ The bone composite was produced by biomimetic synthesis. It shows some features of natural bone in both composition and microstructure. And the collagen moleculars and the nano-crystal hydroxyapatite assemble into ultrastructure similar to natural bone. It possesses porous structure with porosity from 100μm to 500μm after mixed with PLA (poly lactic acid).
摘要:@@ Calcium phosphate ceramics are widely used as biomaterials to substitute or/and repair hard tissues because of their excellent biocompatibility and bioactivity. Among them, hydroxyapatite (HA) is the most promising material. However, their mechanical brittleness restrains them from being used as load-bearing implants.
摘要:@@ IntroductionrnAs a member of the bone morphogenetic protein (BMP) family, BMP-2 plays important roles not only in bone regeneration and bone repair but also in cell proliferation, apoptosis, differentiation and morphogenesis. The BMP-2 remarkable ability to stimulate new bone growth results in the development of a novel therapy strategy for bone mass defect due to accidents or diseases. Because the BMP-2 itself, in conjunction with a suitable matrix, is sufficient to stimulate genesis of new bone, the genetically engineered BMP-2 has good applied prospects.
摘要:@@ to study the affection of loading rhBMP-2 in CPC on the CPC's solidification and the compound's properties.such as ingredient, biomechanics strength, crystal structure and cellular structure, and by what ratio the affection can be minimized; to provide the theoretical basis for compounding rhBMP-2 with CPC. Methods: CPC and rhBMP-2 were compounded in the ratio of lg CPC powder to 1, 3, 5, 10mg rhBMP-2 respectively.
摘要:@@ In the recent years, bioceramic materials have been widely used in the clinics. They are mainly fabricated as the substitution of human hard tissue, such as artificial bone and false tooth. As a medical implant, those that have similar structure to human bone have better biocompatibility and osteoinductional property. So it is necessary to design bone model close to human bone.
摘要:@@ The carbon fiber and carbon fiber for complex materials implanted have been applied to the clinic medicine, in which they are served as the materials for repairing tissues and organs as well as the materials of artificial tissuesand organs. The carbon fiber also acts as the surrogate of extracellular matrix in the study of tissue engineering tendon,and so on.
摘要:@@ INTRODUCTIONrnBiological apatites, such as the mineral component of teeth and bones, are poorly crystalline, carbonate-containing analogs of hydroxyapatite. The reactivity ofhard tissue will be improved with increased of carbonate contents in certain extent.
摘要:@@ Microfabrication, the generation of small structures is essential for much of themodern science and technology. Traditional technology of lithography is expensiveand limited to generate micropattern on surfaces of materials. Recently, anotherkind of technology of so-called soft-lithography is developed.
摘要:@@ Peptide nucleic acid (PNA) is a DNA mimic that was originally developed by Peter E Nielsen in 1991 as a reagent for sequence-specific recognition of double stranded (ds) DNA by a conventional triple helix type principle.
摘要:@@ INTRODUCTIONrnSince their introduction in mid-1980s, polyamidoamide (P AMAM) dendrimershave attracted considerable attention because of their unique structures and properties. According to preliminary studies in animals, PAMAM dendrimers are non-immunogenic, very low in vivo toxicity and can be excreted by urine and feces.
摘要:@@ The toxicity and biocompatibility of medical devices and biological material areprominent facts in evaluation of the material. There are two major methods to evaluate the biocompatibility of biological materials . one kind is to do vivo. The materialor extracts are used to study the effect of the material on the growth, metabolismand proliferation of the histocyte.