Two starting collagens, sponge and floc collagen, were used to prepare
collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had
200μm pore size. However, there was a difference in the microstructure of the pore walls for the
composites derived from the two collagens, the pore walls in sponge collagen/TCP composite
were still porous and had 200 nm micropores size, TCP particles were trapped in collagen
matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles
were embedded. The difference could be attributed to the starting collagen with different status.
Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali
treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls
after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment
could not be able to separate the fibrils, this remains as micropores in pore walls after
freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration.
MTT test results showed the two composites had good cytocompatibility, and sponge
collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could
result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is
suitable for cell growth.
Preparation and analysis of photochromic behavior of carboxymethyl chitin derivatives containing spiropyran moieties
