BC/HAp

Finally, BC/HAp hybrids can also be prepared by aggregation of the two phases in aqueous suspension, after previous disintegration of BC membrane [271, 275], or by regeneration of BC nanofibers from BC dissolved in 4-methylmorpholine-4-oxide... 

Figure 2.29 Typical aspect of BC/HAp hybrid, in which HAp particles were added to the static culture media, (a) surface of precipitated HAp (b) pure BC (c) HAp particles inside the BC network (d) distribution of HAp particles in BC network. Reproduced with permission from [272].

Figure 2.30 Typical FESEM aspect of BC BC/PVP and BC/HAp hybrids obtained by sequentially soaking BC membranes previously treated with poly(vinylpirrolidone), with Ca "" and PO solutions. Reproduced with permission from [276].

Bacterial cellulose (BC)/HAp nanocomposites were examined by Wan et al. [279]. The most striking features of BC are its high mechanical sdength and modulus, as well as its biodegradability. Compared with other natural biodegradable polymers, BC presents much better mechanical properties, which are required in most cases when used as scaffold in tissue engineering. Compared with animal-derived polymers, BC is free of any occurrence of cross-infection that can be associated with collagen [276]. The authors found that there are different interactions between unphosphorylated and phosphorylated BC fibres and HAp, as shown schematically in Fig. 26. 

For specific applications [e.g., bone tissue engineering], BC-gelatin/PA doped with hydroxyapatite [HAp] were synthesized [BC-gelatin/PA/Hap]. The cell compatibility of BC-gelatin/PA/HAp was tested with mesenchymal stem cells [58]. The results indicated that the composite supported cell growth and proliferation, over 7 days of cultivation. Studies on the effectiveness of composites in vitro and in vivo behavior should be further explored. 

Fig. 26 Various interaction processes between BC and HAp. (a) HAp growth on unphosphorylated BC (b) phosphorylation of BC (c) HAp growth on phosphorylated BC. Reprinted from [279] with permission from Elsevier...

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