Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-University, Munich, Germany.
Biomaterials. 2012 Feb;33(5):1554-62. doi: 10.1016/j.biomaterials.2011.10.053. Epub 2011 Nov 9.
The engineered and recombinant spider silk protein eADF4(C16) has been shown to be a promising biomaterial for the use as drug delivery system. In previous studies, eADF4(C16) particles were loaded with low molecular weight drugs exhibiting a positive net-charge and sufficient hydrophobicity. Here, we demonstrate that also macromolecular drugs like proteins can be loaded on eADF4(C16) particles. Using lysozyme as a model protein, remarkably high loading of up to 30% [w/w] was feasible and high loading efficiencies of almost 100% were obtained. Furthermore, using confocal laser scanning microscopy, it is demonstrated that fluorescently labeled lysozyme is not only adsorbed to the negatively charged particles' surface, but also diffusing into the matrix of eADF4(C16) particles. The release of lysozyme is shown to be dependent on the ionic strength and pH of the release medium. To improve the long-term stability of eADF4(C16) containing dispersions, lyophilization is shown as a suitable tool. Disaccharides (sucrose, trehalose) and mannitol served as stabilizers to prevent aggregation and/or particle degradation during freeze-drying. The slowly biodegradable eADF4(C16) particles are a promising new particulate drug carrier system for the delivery of susceptible drugs like therapeutic proteins.
工程化和重组蜘蛛丝蛋白 eADF4(C16) 已被证明是一种很有前途的生物材料，可作为药物传递系统。在以前的研究中，eADF4(C16) 颗粒负载带正净电荷和足够疏水性的低分子量药物。在这里，我们证明了像蛋白质这样的大分子药物也可以负载到 eADF4(C16) 颗粒上。使用溶菌酶作为模型蛋白，可实现高达 30%[w/w]的高负载量，并且几乎可以达到 100%的高负载效率。此外，使用共聚焦激光扫描显微镜，证明荧光标记的溶菌酶不仅吸附在带负电荷的颗粒表面，而且还扩散到 eADF4(C16)颗粒的基质中。溶菌酶的释放被证明依赖于释放介质的离子强度和 pH 值。为了提高含有 eADF4(C16)的分散体的长期稳定性，冻干被证明是一种合适的工具。二糖（蔗糖、海藻糖）和甘露醇用作稳定剂，以防止在冷冻干燥过程中聚集和/或颗粒降解。缓慢可生物降解的 eADF4(C16)颗粒是一种有前途的新型颗粒药物载体系统，可用于输送易受影响的药物，如治疗性蛋白质。
