Visualization of in vivo degradation of aliphatic polyesters by a fluorescent dendritic star macromolecule
Visualization of in vivo degradation of aliphatic polyesters by a fluorescent dendritic star macromolecule
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荧光树枝状星形大分子体内脂肪族聚酯降解的可视化
DOI：
10.1088/1748-6041/10/6/065003
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发表时间：
2015
影响因子：
4
通讯作者：
Cai Qing
中科院分区：
文献类型：
--
作者：
Duan Shun;Ma Shiqing;Huang Zhaohui;Zhang Xu;Yang Xiaoping;Gao Ping;Yin Meizhen;Cai Qing
在组织工程中，大多数聚合物支架随着新组织的形成而沿着降解。因此，有必要研究支架的体内降解。在这项研究中，一个荧光的苝二酰亚胺为核心（PDI为核心）的树枝状星星大分子轴承多胺（d-p48）被纳入到可生物降解的聚酯纳米纤维支架通过静电纺丝作为指示剂。聚酯/d-p48共混纳米纤维在激发光照射下能发出较强的红色荧光。首先，使用可缓慢降解的聚酯，聚（L-丙交酯）（PLLA）/d-p48纳米纤维浸泡在磷酸盐缓冲盐水中不同的时间长度，以确定d-p48大分子从纳米纤维中扩散释放的可能性。然后将PLLA/d-p48纳米纤维皮下植入小鼠体内并放置长达2周。在这两种情况下，都没有检测到掺入的d-p48大分子的不期望的释放，并且通过荧光显微镜在体内清楚地观察到纳米纤维。使用快速降解的聚酯，聚（丙交酯-共-乙交酯）（PLGA）/d-p48纳米纤维进行静电纺丝和皮下植入，以确定在12周内通过荧光监测体内降解的可能性。结果表明，使用动物荧光成像系统可以清晰地观察到PLGA/d-p48纳米纤维支架的位置和轮廓。随着支架的降解，荧光强度逐渐减弱。在检测过程中未发现对肝脏和肾脏的副作用。本研究表明，以PDI为核心的树枝状星星大分子可作为生物可降解脂肪族聚酯在体内的一种稳定的生物成像指示剂。
In tissue engineering, most polymeric scaffolds should degrade along with the formation of the new tissues. Therefore, it is necessary to look into the in vivo degradation of scaffolds. In this study, a fluorescent perylenediimide-cored (PDI-cored) dendritic star macromolecule bearing multiple amines (d-p48) was incorporated into biodegradable polyester nanofibrous scaffolds by eletrospinning as an indicator. The polyester/d-p48 blend nanofibers could emit strong red fluorescence when they were irradiated under exciting light. Initially, using slowly degradable polyester, poly(L-lactide) (PLLA)/d-p48 nanofibers were soaked in phosphate buffered saline for various lengths of time to determine the possible diffusing release of d-p48 macromolecule from nanofibers. The PLLA/d-p48 nanofibers were then implanted subcutaneously into mice and left for up to 2 weeks. In both cases, no undesirable release of the incorporated d-p48 macromolecule was detected, and the nanofibers were clearly visualized in vivo by fluorescence microscopy. Using a fast degradable polyester, poly(lactide-co-glycolide) (PLGA)/d-p48 nanofibers were electrospun and implanted subcutaneously to determine the possibility of monitoring in vivo degradation by fluorescence during 12 weeks. The results showed that the location and the contour of PLGA/d-p48 nanofibrous scaffolds could be clearly visualized using an animal fluorescent imaging system. The fluorescent intensities decreased gradually with the degradation of the scaffolds. No side effects on liver and kidney were found during the detection. This study indicates that the fluorescent PDI-cored dendritic star macromolecule can be used as a stable bioimaging indicator for biodegradable aliphatic polyesters in vivo.