Kim Tae-Hyun, Singh Rajendra K, Kang Min Sil, Kim Joong-Hyun, Kim Hae-Won
Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, Republic of Korea.
Nanoscale. 2016 Apr 21;8(15):8300-11. doi: 10.1039/c5nr07933k.
The recent development of bioactive glasses with nanoscale morphologies has spurred their specific applications in bone regeneration, for example as drug and gene delivery carriers. Bone engineering with stem cells genetically modified with this unique class of nanocarriers thus holds great promise in this avenue. Here we report the potential of the bioactive glass nanoparticle (BGN) system for the gene delivery of mesenchymal stem cells (MSCs) targeting bone. The composition of 15% Ca-added silica, proven to be bone-bioactive, was formulated into surface aminated mesoporous nanospheres with enlarged pore sizes, to effectively load and deliver bone morphogenetic protein-2 (BMP2) plasmid DNA. The enlarged mesopores were highly effective in loading BMP2-pDNA with an efficiency as high as 3.5 wt% (pDNA w.r.t. BGN), a level more than twice than for small-sized mesopores. The BGN nanocarriers released the genetic molecules in a highly sustained manner (for as long as 2 weeks). The BMP2-pDNA/BGN complexes were effectively internalized to rat MSCs with a cell uptake level of ∼73%, and the majority of cells were transfected to express the BMP2 protein. Subsequent osteogenesis of the transfected MSCs was demonstrated by the expression of bone-related genes, including bone sialoprotein, osteopontin, and osteocalcin. The MSCs transfected with BMP2-pDNA/BGN were locally delivered inside a collagen gel to the target calvarium defects. The results showed significantly improved bone regeneration, as evidenced by the micro-computed tomographic, histomorphometric and immunohistochemical analyses. This study supports the excellent capacity of the BGN system as a pDNA-delivery nanocarrier in MSCs, and the engineered system, BMP2-pDNA/BGN with MSCs, may be considered a new promising candidate to advance the therapeutic potential of stem cells through genetic modification, targeting bone defects and diseases.
具有纳米级形态的生物活性玻璃的最新进展推动了其在骨再生中的特定应用，例如作为药物和基因递送载体。因此，利用这类独特的纳米载体对干细胞进行基因改造的骨工程在这一领域具有巨大的潜力。在此，我们报告了生物活性玻璃纳米颗粒（BGN）系统用于靶向骨的间充质干细胞（MSCs）基因递送的潜力。已证明具有骨生物活性的15%钙添加二氧化硅的成分被制成具有扩大孔径的表面胺化介孔纳米球，以有效负载和递送骨形态发生蛋白-2（BMP2）质粒DNA。扩大的介孔在负载BMP2-pDNA方面非常有效，效率高达3.5 wt%（相对于BGN的pDNA），这一水平是小尺寸介孔的两倍多。BGN纳米载体以高度持续的方式释放遗传分子（长达2周）。BMP2-pDNA/BGN复合物有效地内化到大鼠MSCs中，细胞摄取水平约为73%，并且大多数细胞被转染以表达BMP2蛋白。转染后的MSCs随后的成骨作用通过包括骨涎蛋白、骨桥蛋白和骨钙素在内的骨相关基因的表达得以证明。用BMP2-pDNA/BGN转染的MSCs被局部递送到胶原凝胶内的目标颅骨缺损处。微计算机断层扫描、组织形态计量学和免疫组织化学分析表明，结果显示骨再生得到显著改善。这项研究支持了BGN系统作为MSCs中pDNA递送纳米载体的卓越能力，并且工程系统BMP2-pDNA/BGN与MSCs一起，可能被认为是一种新的有前途的候选物，可通过基因改造提高干细胞的治疗潜力，靶向骨缺损和疾病。
