Venkatesh Siddarth, Wower Jacek, Byrne Mark E
Biomimetic and Biohybrid Materials, Biomedical Devices, and Drug Delivery Laboratories, Department of Chemical Engineering, Auburn University, Auburn, Alabama 36849, USA.
Bioconjug Chem. 2009 Sep;20(9):1773-82. doi: 10.1021/bc900187b.
Biohybrid platforms such as synthetic polymer networks engineered from artificial and natural materials hold immense potential as drug and gene delivery vehicles. Here, we report the synthesis and characterization of novel polymer networks that release oligonucleotide sequences via enzymatic and physical triggers. Chemical monomers and acrylated oligonucleotides were copolymerized into networks, and phosphoimaging revealed that 70% of the oligonucleotides were incorporated into the networks. We observed that the immobilized oligonucleotides were readily cleaved when the networks were incubated with the type II restriction enzyme BamHI. The diffusion of the cleaved fragments through the macromolecular chains resulted in relatively constant release profiles very close to zero-order. To our knowledge, this is the first study which harnesses the sequence-specificity of restriction endonucleases as triggering agents for the cleavage and release of oligonucleotide sequences from a synthetic polymer network. The polymer networks exhibited an oligonucleotide diffusion coefficient of 5.6 x 10(-8) cm(2)/s and a diffusional exponent of 0.92. Sigmoidal temperature responsive characteristics of the networks matched the theoretical melting temperature of the oligonucleotides and indicated a cooperative melting transition of the oligonucleotides. The networks were also triggered to release a RNA-cleaving deoxyribozyme, which degraded a HIV-1 mRNA transcript in vitro. To tailor release profiles of the oligonucleotides, we controlled the structure of the macromolecular architecture of the networks by varying their cross-linking content. When incubated with DNase I, networks of cross-linking content 0.15%, 0.22%, and 0.45% exhibited oligonucleotide diffusion coefficients of 1.67 x 10(-8), 7.65 x 10(-9), and 2.7 x 10(-9) cm(2)/s, and diffusional exponents of 0.55, 0.8, and 0.8, respectively. The modular nature of our platform promises to open new avenues for the creation and optimization of a rich toolbox of novel drug and gene delivery platforms. We anticipate further inquiry into nucleic acid based programmable on-demand switches and modulatory devices of exquisite sensitivity and control.
生物杂交平台，如由人工和天然材料构建的合成聚合物网络，作为药物和基因递送载体具有巨大潜力。在此，我们报告了通过酶促和物理触发释放寡核苷酸序列的新型聚合物网络的合成与表征。化学单体和丙烯酸化寡核苷酸共聚形成网络，磷成像显示70%的寡核苷酸被整合到网络中。我们观察到，当网络与II型限制性内切酶BamHI孵育时，固定化的寡核苷酸很容易被切割。切割片段通过大分子链的扩散导致相对恒定的释放曲线，非常接近零级。据我们所知，这是第一项利用限制性内切核酸酶的序列特异性作为触发剂，从合成聚合物网络中切割和释放寡核苷酸序列的研究。该聚合物网络的寡核苷酸扩散系数为5.6×10(-8) cm(2)/s，扩散指数为0.92。网络的S形温度响应特性与寡核苷酸的理论解链温度相匹配，表明寡核苷酸发生了协同解链转变。这些网络还被触发释放一种RNA切割脱氧核酶，该酶在体外降解HIV-1 mRNA转录本。为了调整寡核苷酸的释放曲线，我们通过改变交联含量来控制网络大分子结构的结构。当与DNase I孵育时，交联含量为0.15%、0.22%和0.45%的网络的寡核苷酸扩散系数分别为1.67×10(-8)、7.65×10(-9)和2.7×10(-9) cm(2)/s，扩散指数分别为0.55、0.8和0.8。我们平台的模块化性质有望为创建和优化丰富的新型药物和基因递送平台工具箱开辟新途径。我们期待对基于核酸的可编程按需开关以及具有极高灵敏度和可控性的调节装置进行进一步研究。
