Lim Y B, Han S O, Kong H U, Lee Y, Park J S, Jeong B, Kim S W
School of Chemistry & Molecular Engineering, Seoul National University, Korea.
Pharm Res. 2000 Jul;17(7):811-6. doi: 10.1023/a:1007552007765.
The aim of this study was to develop a non-toxic polymeric gene carrier. For this purpose, biodegradable cationic polymer, poly[alpha-(4-aminobutyl)-L-glycolic acid] (PAGA) was synthesized. PAGA was designed to have ester linkage because polyesters usually show biodegradability.
Degradation of PAGA in an aqueous solution was followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). PAGA/DNA complexes were characterized by gel electrophoresis, atomic force microscopy (AFM), dynamic light scattering (DLS). The transfection was measured by using the beta-galactosidase reporter gene.
PAGA was degraded in aqueous solution very quickly and the final degradation product was a monomer (L-oxylysine). Formation of self-assembling biodegradable complexes between PAGA and DNA at a charge ratio 1:1 (+/-) was confirmed by gel band shift assay and AFM. In these studies, controlled release of DNA from the complexes could be seen. The complexes showed about 2-fold higher transfection efficiency than DNA complexes of poly-L-lysine (PLL), a structural analogue of PAGA, which is the most commonly used poly-cation for gene delivery. The polymer did not show cytotoxicity, possibly because of its degradability and the biocompatibility of the monomer.
The use of the biodegradable poly-cation, PAGA, as a DNA condensing agent will be useful in safe gene delivery.
本研究的目的是开发一种无毒的聚合物基因载体。为此，合成了可生物降解的阳离子聚合物聚α-(4-氨基丁基)-L-乙醇酸。由于聚酯通常具有生物降解性，PAGA被设计为具有酯键。
通过基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)跟踪PAGA在水溶液中的降解情况。通过凝胶电泳、原子力显微镜(AFM)和动态光散射(DLS)对PAGA/DNA复合物进行表征。使用β-半乳糖苷酶报告基因测量转染情况。
PAGA在水溶液中降解非常快，最终降解产物是单体(L-氧赖氨酸)。通过凝胶带迁移试验和AFM证实了PAGA与DNA在电荷比为1:1(±)时形成自组装可生物降解复合物。在这些研究中，可以看到DNA从复合物中得到控释。该复合物的转染效率比PAGA的结构类似物聚-L-赖氨酸(PLL)的DNA复合物高约2倍，PLL是最常用的用于基因递送的聚阳离子。该聚合物没有显示出细胞毒性，可能是因为其可降解性和单体的生物相容性。
使用可生物降解的聚阳离子PAGA作为DNA凝聚剂将有助于安全的基因递送。
