Abstract: To meetthe requirement of scaffold in bone tissue engineering with controllable macroand micro pores and good mechanical properties, chitosan-nanohydroxyapatite 3Dporous scaffolds were fabricated by low- temperature depositionmanufacturing. A load force driven injecting nozzle was proposed and developedto extrude natural derived polymers. Strand of biomaterials was extruded steady,uniformly and bonded to each other well. Hierarchial structure of scaffold wasstudied. Morphology of scaffold’s pores contains macropores and micropores. Macroporesare fabricated controllably according to fabricating path. Morphology of microporesare affected by materials ratio and fabricating temperature, cross-link, etc. A higher nanohydroxyapatite ratioleads to smaller micropores. Larger micropores are obtained under lowerfabriacating temperature. Cross-link causes micropores become smaller. Resultsof in vitro mouse MC3T3-E1 cellculture studies reveal a good biocompatibility for a high nanohydroxyapatitecontent scaffold. The regular and highly interconnected macropores ensure cellsto migrate into the center of 3D scaffold.

Key words: rapid prototyping, low-temperaturedeposition, scaffold, chitosan, nano-hydroxyapatite