Bone regeneration in a rat cranial defect with delivery of PEI-condensed plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4)
Bone regeneration in a rat cranial defect with delivery of PEI-condensed plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4)
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DOI：
10.1038/sj.gt.3302439
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发表时间：
2005-03-01
期刊：
影响因子：
5.1
通讯作者：
Mooney, DJ
中科院分区：
文献类型：
--
作者：
Huang, YC;Simmons, C;Mooney, DJ
骨组织工程的基因治疗方法已被广泛探索。虽然编码成骨因子的质粒 DNA 的局部递送对于促进骨再生很有吸引力，但质粒递送固有的低转染效率可能会限制这种方法。我们假设，可以通过将质粒 DNA 与非病毒载体（例如聚乙烯亚胺（PEI））缩合，并从聚（乳酸-乙醇酸）（PLGA）支架以持续和局部的方式递送质粒 DNA，来克服这一限制。为了解决这种可能性，将编码骨形态发生蛋白 4 (BMP-4) 的质粒 DNA 的支架植入颅骨临界尺寸缺损处，持续时间长达 15 周。对照条件包括无支架（缺陷留空）、空白支架（无递送的 DNA）和封装质粒 DNA 的支架（非浓缩）。随着时间的推移，对缺损部位的组织学和微计算机断层扫描分析表明，当将封装浓缩 DNA 的支架放置在缺损中时，缺损边缘和缺损部位内的骨再生显着。相比之下，当使用空白支架填充缺损时，骨形成主要局限于封装质粒DNA的支架内的缺损边缘。组织形态计量学分析显示，在每个时间点，相对于空白支架和掺入未缩合DNA的支架，掺入缩合DNA的支架内的总骨形成显着增加（至少4.5倍）。此外，与空白支架和掺入未缩合DNA的支架相比，掺入缩合DNA的支架内的类骨质和矿化组织密度显着增加，这表明缩合DNA的递送导致缺损区域内更完全的矿化组织再生。这项研究表明，封装了编码 BMP-4 的 PEI 浓缩 DNA 的支架输送系统能够增强骨形成，并可能在其他组织类型中得到应用。
Gene therapy approaches to bone tissue engineering have been widely explored. While localized delivery of plasmid DNA encoding for osteogenic factors is attractive for promoting bone regeneration, the low transfection efficiency inherent with plasmid delivery may limit this approach. We hypothesized that this limitation could be overcome by condensing plasmid DNA with nonviral vectors such as poly( ethylenimine) (PEI), and delivering the plasmid DNA in a sustained and localized manner from poly( lactic-co-glycolic acid) ( PLGA) scaffolds. To address this possibility, scaffolds delivering plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4) were implanted into a cranial critical-sized defect for time periods up to 15 weeks. The control conditions included no scaffold ( defect left empty), blank scaffolds ( no delivered DNA), and scaffolds encapsulating plasmid DNA ( non-condensed). Histological and microcomputed tomography analysis of the defect sites over time demonstrated that bone regeneration was significant at the defect edges and within the defect site when scaffolds encapsulating condensed DNA were placed in the defect. In contrast, bone formation was mainly confined to the defect edges within scaffolds encapsulating plasmid DNA, and when blank scaffolds were used to fill the defect. Histomorphometric analysis revealed a significant increase in total bone formation ( at least 4.5-fold) within scaffolds incorporating condensed DNA, relative to blank scaffolds and scaffolds incorporating uncondensed DNA at each time point. In addition, there was a significant increase both in osteoid and mineralized tissue density within scaffolds incorporating condensed DNA, when compared with blank scaffolds and scaffolds incorporating uncondensed DNA, suggesting that delivery of condensed DNA led to more complete mineralized tissue regeneration within the defect area. This study demonstrated that the scaffold delivery system encapsulating PEI-condensed DNA encoding for BMP-4 was capable of enhancing bone formation and may find applications in other tissue types.