Preparation of chitosan-gelatin scaffold containing tetrandrine-loaded nano-aggregates and its controlled release behavior

A well-timed delivery of bioactive macromolecules from the porous scaffolds is very important in tissue engineering. Tetrandrine (Ted) is one of a large number of known plant derived bisbenzylisoquinoline alkaloids and is obtained from the roots of Stephania tetrandria. Ted can be used as a modifier to poly(L-lactic acid) scaffolds to promote chondrocyte differentiation and secrete type H collagen. But the effect of Ted on chondrocyte's behavior strongly depends on the concentration of Ted in the culture media. Here amphiphilic diblock copolymer (PLAE) composed Of L-lactide and methoxy poly(ethylene glycol) (MePEG) was prepared and the Ted loaded copolymeric nanospheres were obtained by self-emulsification and then solvent evaporation. The mean sizes of core/shell type PLAE nanospheres and Ted-loaded nanospheres are about 60 and 100 nm, respectively. Chitosan-gelatin (Cs-Gel) porous scaffolds loaded with PLAE-Ted nanospheres were fabricated through freeze drying. Ted release behaviors from PLAE-Ted nanospheres and porous scaffolds were investigated. The result shows that the Ted-loaded nanospheres could be embedded within Cs-Gel scaffolds and no initial burst release could be observed in the release patterns. Here a room can be provided for the scaffolds to sustained release bioactive component in tissue engineering. (c) 2007 Elsevier B.V. All fights reserved.