Synthesis and Characterization of a Matrix-Metalloproteinase Responsive Silk-Elastinlike Protein Polymer
Synthesis and Characterization of a Matrix-Metalloproteinase Responsive Silk-Elastinlike Protein Polymer
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DOI：
10.1021/bm3013692
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发表时间：
2013-03-01
影响因子：
6.2
通讯作者：
Ghandehari, Hamidreza
中科院分区：
文献类型：
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作者：
Gustafson, Joshua A.;Price, Robert A.;Ghandehari, Hamidreza
丝蛋白弹性蛋白聚合物(SELP)是由丝蛋白串联重复序列(GAGS)和弹性蛋白(GVGVP)单位组成的重组聚合物。通过改变这些重复序列的长度和组成，可以控制SELP水凝胶的性质，以用于特定的应用，包括核酸和病毒输送以及组织工程。在这里，SELP的结构被进一步修改，以包括对基质金属蛋白酶(MMPs)敏感的序列。MMPs是一个普遍存在的细胞外基质修饰酶家族，通常与许多重要过程相关。在许多类型的实体肿瘤中，局部高水平的MMPs水平升高。通过用基质金属蛋白酶敏感的多肽序列修饰SELP骨架，制备了可被MMPs降解的水凝胶。通过与基质金属蛋白酶-2和基质金属蛋白酶-9孵育来检测聚合物对基质金属蛋白酶的敏感性，分别在36小时和48小时时使所有全长聚合物完全切割，而对未修饰的SELP没有明显的影响。通过暴露于基质金属蛋白酶-2或基质金属蛋白酶-9 2周来检测水凝胶的敏感性，在此期间，10个样本分析水凝胶中的蛋白质丢失和100 nm荧光小球的释放。在孵化期之后，水凝胶在机械压缩下进行测试，以检查由于降解造成的水凝胶硬度的损失。结果发现，基质金属蛋白酶-2和基质金属蛋白酶-9分别导致63%和44%的蛋白质丢失，65%和95%的基质金属蛋白酶敏感水凝胶释放增加，压缩弹性系数下降41%和29%。这些结果表明，在MMPs过度表达的情况下，对MMPs有反应的SELP有可能用于局部输送生物活性物质。
Silk-elastinlike protein polymers (SELPs) are recombinant polymers consisting of tandem repeats of silk (GAGAGS) and elastin (GVGVP) units. By modification of the length and composition of these repeats, the properties of SELP hydrogels can be controlled for specific applications including nucleic acid and virus delivery and tissue engineering. Here, the structure of SELPs is further modified to include a sequence that is sensitive to matrix-metalloproteinases (MMPs). MMPs are a ubiquitous family of extracellular matrix-modifying enzymes that are commonly associated with numerous vital processes. Increased levels of MMPs are found at high levels locally in many types of solid tumors. By modifying the SELP backbone with MMP-sensitive peptide sequences, a hydrogel that p degradable by MMPs was produced. The MMP-sensitivity of the polymer was examined by incubation with MMP-2 and MMP-9, which yielded complete cleavage Of all full-length polymers by 36 hours and 48 hours, respectively, with no observable effect on unmodified SELP. Hydrogel sensitivity was tested by exposure to MMP-2 or MMP-9 for 2 weeks, during which sample's were ten to analyze protein loss from the hydrogel and release of 100 nm fluorescent beads. Following the incubation period, hydrogels were tested in mechanical compression to examine the loss of hydrogel stiffness due to degradation. It was found that MMP-2 and MMP-9 caused 63% and 44%, increased protein loss and 65% and 95% increased release from MMP-sensitive hydrogels, while the compressive modulus decrease 41% and 29%. These results suggest the potential of MMP-responsive SELPs for localized delivery of bioactive agents Where MMPs are overexpressed.