ABSTRACT
Laboratory animals are an important part of life sciences and medical researches, as well an important support for the science and technology innovation in our country. Laboratory animal science is of great significance to the protection of human health,food safety and biological safety. Laboratory animals are indispensable in the development of food safety,drugs,vaccines and biological products and the studies of human disease pathogenesis. In order to adapt to the requirements for overall development of the laboratory animal industry in China, our institute has independently developed the Network Training System for Laboratory Animal Managers. This system is an online education and training platform which integrates the practical operation and theoretical knowledge of laboratory animals,including seven knowledge modules such as animal welfare,animal breeding,animal surgery and so on. The training subjects of the system include managers, experiment operators, laboratory animal doctors and breeders, aimed at accelerating the personnel training and team building of laboratory animal sciences,and promoting the transformation and development of personnel training in laboratory animal industry.
ABSTRACT
ObjectiveTo investigate the in vivo biological performance of 5 porous bioceramic scaffolds,which were bioglass,β-tricalcium phosphate (β-TCP),hydroxyapatite (HA),β-calcium silicate (β-CS) and α-CS,implanted in rabbit dorsal muscle.MethodsThe 5 porous bioceramic scaffolds were fabricated by adding pore-forming materials and sintering,and then were investigated by X-ray diffraction,porosity mensuration and biomechanics test.The scaffolds were implanted into rabbit dorsal muscle for 4,8,12,16 weeks,respectively.The samples were analyzed by X-ray,Micro-CT,histological analysis,scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The expression of bone morphogenetic protein(BMP-2) and BMP-7 in the muscle in touch with bioceramic scaffolds were also investigated by polymerase chain reaction(PCR).ResultsThe characteristic analysis of 5 scaffolds showed that the sequence of compressive strength was bioglass＞α-CS＞β-CS＞β-TCP＞HA,the sequence of elasticity modulus was α-CS＜β-TCP＜HA＜β-CS＜bioglass.It was confirmed by X-ray,Micro-CT and histological analysis that the sequence of biodegradability was β-CS＞α-CS＞β-TCP＞bioglass＞HA.The histological observation showed no new bone formation in five scaffolds.A Ca-P layer was formed in the surface of bioglass,α-CS and β-CS,which suggested their in vivo bioactivity.After 16 weeks,the expression of BMP-2 and BMP-7 was found only in β-CS.Conclusion The porous calcium silicate scaffold,which was promising for bone tissue engineering,was with good in vivo bioactivity and biodegradability,without in vivo osteoinductivity.
ABSTRACT
Bioactive poly-(DL-lactic acid) (PDLLA)-wollastonite composite films are successfully fabricated using surface modified wollastonite (m beta-CaSiO 3) particles through solvent casting-evaporation method. The surface modification of beta-CaSiO3 particles are conducted by reaction of the ceramic particles with dodecyl alcohol. Surface morphology, tensile strength, and bioactivity of the composite films are investigated. The results show that the particle distribution and tensile strength of the composite films with modified beta-CaSiO3 particles are significantly improved while the bioactivity is retained. As a result, the maximum tensile strength is enhanced 52.2% when compared with the PDLLA-beta-CaSiO3 composite films prepared using unmodified beta-CaSiO3 particles when the inorganic filler content is 15 wt%. Scanning electron microscopy (SEM) observation suggests that the modified m beta-CaSiO3 particles are homogeneously dispersed in the PDLLA matrix. The bioactivity of the composite films is evaluated by soaking in a simulated body fluid (SBF) and the result suggests that the modified composite film is still bioactive and can induce the formation of HAp on its surface after the immersion in SBF, despite the bonded dodecyl alkyl on the surface of the inorganic particles. All these results imply that the surface modification of beta-CaSiO3 with dodecyl alcohol is an effective approach to prepare PDLLA-beta-CaSiO3 composite with improved properties.
