School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
Int J Pharm. 2013 Mar 10;445(1-2):196-202. doi: 10.1016/j.ijpharm.2013.01.014. Epub 2013 Jan 14.
Calcium phosphate (CAP) has a wide range of applications in biomedical systems. Although there is great potential for the use of CAP in the development of gene delivery systems, the uncontrollable growth of CAP crystal makes it difficult to use in a practical nano-gene delivery system. The purpose of this study was to develop nano-sized CAP particles containing nucleic acids (e.g. DNA, siRNA). The CAP nano-aggregates (CAP/pDNA/dopa-Chi) were successfully prepared by serial addition of plasmid DNA (pDNA) and dopa (3,4-dihydroxy-L-phenylalanine) modified chitosan to growing CAP particles in calcium phosphate solution. The addition of the dopa moiety is thought to enable chitosan adsorption onto the surface of forming calcium phosphate particles to prevent further growth. The CAP/pDNA/dopa-Chi significantly increased the serum stability of pDNA, and showed high cellular uptake efficiency and trans-gene expression. Additionally, the chitosan stabilized CAP nano-aggregates were also prepared for siRNA delivery (CAP/siRNA/dopa-Chi) via the same method as for CAP/pDNA/dopa-Chi. A notable siRNA gene silencing effect of CAP/siRNA/dopa-Chi was exhibited without any sign of cytotoxicity.
磷酸钙 (CAP) 在生物医学系统中有广泛的应用。尽管 CAP 在基因传递系统的开发中有很大的应用潜力，但 CAP 晶体的不可控生长使其难以在实际的纳米基因传递系统中使用。本研究旨在开发含有核酸（如 DNA、siRNA）的纳米级 CAP 颗粒。通过在磷酸钙溶液中向生长的 CAP 颗粒连续添加质粒 DNA（pDNA）和多巴（3,4-二羟基-L-苯丙氨酸）修饰的壳聚糖，成功制备了纳米级 CAP 聚集体（CAP/pDNA/dopa-Chi）。添加多巴部分被认为能够使壳聚糖吸附到形成的磷酸钙颗粒表面上，以防止进一步生长。CAP/pDNA/dopa-Chi 显著提高了 pDNA 的血清稳定性，并表现出高细胞摄取效率和转基因表达。此外，还通过与 CAP/pDNA/dopa-Chi 相同的方法制备了壳聚糖稳定的 CAP 纳米聚集体用于 siRNA 传递（CAP/siRNA/dopa-Chi）。CAP/siRNA/dopa-Chi 表现出显著的 siRNA 基因沉默效果，而没有任何细胞毒性的迹象。
