This is the optimum process to achieve the sustained LY2109761 chemical structure release purpose. Figure 7 OM photos and vitamin B 12 cumulative release (%) of chemical cross-linking CS55 hydrogel beads. The beads are chemical-cross-linked by GA and GP after TPP 5% ionically cross-linked by TPP. Scale bar = 200 μm. Finally, the comparison of the different molecular weight effects of biomolecules was investigated. Figure 8 shows that the slower drug release occurred in larger biomolecules, displaying in the order of BSA (65, 000 Da) < cytochrome c (12,327 Da) < vitamin B12 (1,355 Da). The result illustrated that the rate of drug
release would be changed with different sizes of biomolecules due to the pore-size barrier of the CS-CDHA carriers. Therefore, a suitable drug carrier would Selleckchem MK-4827 be anticipated to fabricate for various sizes of biomolecules (such as growth factors and therapeutic drugs) to achieve the sustained release for biomedical applications. Figure 8 OM photos and cumulative release (%) of vitamin B 12 , cytochrome c, and BSA
in CS55 hydrogel beads. TPP 10%, scale bar = 200 μm. Conclusion Novel biocompatible hybrid nanocomposites consisting of chitosan and CDHA were successfully synthesized via an in situ precipitation process at pH 9 (Figure 9) for drug delivery purpose. CS/CDHA nanocomposites were then cross-linked into hydrogel beads by tripolyphosphate, glutaraldehyde, and genipin, respectively. Various biomolecules could be encapsulated in the beads and exhibit different release CUDC-907 behaviors. Experimental results show that the drug release
kinetics of the CS-CDHA carriers was affected by the incorporation of CDHA nanoparticles. The slowest release rate was observed in CS73 (30% CDHA addition) due to its more stable structure and smaller pore size. Therefore, CDHA nanocrystal can simultaneously function as a bioactive filler and drug release regulator. The drug release rate of biomolecules also could be modulated by cross-linked agent. The application of GA will produce the densest structures, leading to the slowest drug release of biomolecules. These CS-CDHA carriers also exhibited pH-sensitive behavior. It displayed faster release rate at pH value of 4 new and slowest release rate at pH value of 10, due to swelling behavior of CS at pH 4. It might provide valuable information for a better design of chitosan hybrids for drug-loaded implant with improved bioactivity and controlled drug release function. Furthermore, chitosan-CDHA nanocomposite drug carriers with pH-sensitive property which can lead to intelligent controlled release of drugs can be used as gastric fluid-resistant drug vehicles and for bone repair. Figure 9 Novel chitosan/Ca-deficient hydroxyapatite nanocomposite via an in situ precipitation process at pH 9. Authors’ information LYH is a postdoctoral fellow at the National Taiwan University of Science and Technology.