| Scaffold material is essential to tissue engineering researches. It not only takes effect onoffering structure-support and template for tissue cells and guides tissue regeneration, but alsocontrols tissue structure. Therefore, it is important to find a scaffold material which can notonly provide excellent biocompatibility and biodegradability, but also possesse special shapesand interconnected three-dimensional pores.The study aims at the poorer mechanical property nano-bioglass(NBG) biomaterialsalthough they have the excellent biocompatibility. It is difficult to be used as bonereplacement at the loading site in clinic. In the present study, the mechanical property of NBGhas been improved by adding plastic phase gelatin and hyaluronic acid. Nano bioactive glasshas a unique surface and interfacial effect, small size effect, quantum size effect andmacroscopic quantum tunneling effect. Natural polymer materials，Gelatin (gelatin, Gel) andhyaluronic acid (hyaluronic acid, HA) are natural polymer materials, and because that havethe unique molecular structure (in witch molecular have a large number of hydroxyl groupsand carboxyl groups) and physical and chemical properties they can show unique features invivo.In the present study, NBG has been prepared via the sol-gel method, freeze-dried and PEGas dispersant. The resulting showed that NBG particales prepared with PEG-10000was50～80nm, and the shape of NBG was hollow spherical; The shape of NBG with PEG-20000wasa long strip (10×100nm). With the increase of PEG concentration, the particle sizedecreased.In this work, the scaffolds, composing of gelatin and hyaluronic acid with differentproportions, were prepared by freeze-drying and chemical cross-linked by using1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) as a cross-linker. Thecross-linking and the mass ratio of Gel/HA effected on morphology, mechanical propertiesand swelling ratios of hydrogel were also studied. The results showed that the concentrationof EDC has a little effect on the pore of hydrogel. Increasing the proportion of hyaluronic acidcan increase the swelling ratios and decrease the contact angle of hydrogel.In order to improve the phase compatibility between the polymer and the inorganic phase,NBG was dispersed by ultrasonic, Gel/HA was linked to the surface of the NBG particles byEDC. The grafting modification could improve the tensile strength, tensile modulus andimpact energy of the composites by increasing the phase compatibility. When the scaffolds have high concentration of NBG, witch the mechanical properties and swelling ratios will beget worse. With increasing the contents of NBG in the pore material, the hole wall ofscaffolds become thickening and the hole wall become rough. The morphology of the tensilefracture surface of the composite showed surface-grafted NBG to be dispersedhomogeneously in the Gel/HA matrix.The degradation behaviors of Gel/HA and Gel-HA/NBG composite in PBS and PBS+lysozyme solution were investigated in detail. The resulting showed that the gegradation rateof Gel-HA/NBG was lower than Gel/HA in PBS and PBS+lysozyme solution; PBS+lysozymehas stronger destructive for scaffolds than PBS solution. Gel/HA and Gel-HA/NBG wasdegradation in both solutions; with increasing the degradation time, water taking and waterabsorption of scaffolds are reduced. On the pore walls of scaffolds NBG appearedagglomeration.The biocompatibility of the Gel/HA was further assessed by their in vitro cellular responses.The results indicate that the viability of Gel/HA (9:1) was101%, The cells growth incomposites with different shapes(the elongated shape, round, triangular, polygonal shape).Gel/HA has the nature of non-toxic, good biocompatibility. |
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