Mulinti Pranothi, Shreffler Jacob, Hasan Raquib, Dea Michael, Brooks Amanda E
Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND 58102, USA.
College of Osteopathic Medicine, Rocky Vista University, Ivins, UT 84734, USA.
Pharmaceutics. 2021 Aug 28;13(9):1358. doi: 10.3390/pharmaceutics13091358.
Frequent and inappropriate usage of antibiotics has changed the natural evolution of bacteria by reducing susceptibility and increasing resistance towards antibacterial agents. New resistance mechanisms evolved in the response to host defenses and pharmaceutical interventions are threatening our ability to treat common infections, resulting in increased mortality. In the face of this rising epidemic, antibiotic drug discovery, which has long been overlooked by big pharma, is reaching a critical low. Thus, the development of an infection-responsive drug delivery system, which may mitigate multidrug resistance and preserve the lifetime of our current antibiotic arsenal, has garnered the attention of both popular science and funding agencies. The present work describes the development of a thrombin-sensitive linker embedded into a recombinant spider silk copolymer to create a nanosphere drug delivery vehicle. Recent studies have suggested that there is an increase in thrombin-like activity during infection; thus, drug release from this new "smart" nanosphere can be triggered in the presence of infection. A thrombin sensitive peptide (TSP) was synthesized, and the thrombin cleavage sensitivity was determined by HPLC. The results showed no cleavage of the peptide when exposed to human serum whereas the peptide was cleaved when incubated with exudate. Subsequently, the peptide was coupled with a silk copolymer via EDC-NHS chemistry and formulated into nanospheres encapsulating antibiotic vancomycin. These nanospheres were evaluated for in vitro infection-responsive drug release and antimicrobial activity. Finally, the drug responsive nanospheres were assessed for efficacy in an in vivo septic arthritis model. Our study provides evidence that the protein conjugate was enzyme responsive and can be used to formulate targeted drug release to combat infections against multidrug-resistant bacterial strains.
抗生素的频繁和不当使用通过降低细菌对抗菌剂的敏感性并增加耐药性，改变了细菌的自然进化。为应对宿主防御和药物干预而进化出的新耐药机制正威胁着我们治疗常见感染的能力，导致死亡率上升。面对这一日益严重的流行问题，长期被大型制药公司忽视的抗生素药物研发正处于极低的关键水平。因此，开发一种感染响应型药物递送系统，该系统可能减轻多重耐药性并延长我们现有抗生素库的使用寿命，已引起大众科学和资助机构的关注。目前的工作描述了一种嵌入重组蜘蛛丝共聚物中的凝血酶敏感连接子的开发，以创建一种纳米球药物递送载体。最近的研究表明，感染期间凝血酶样活性会增加；因此，这种新型“智能”纳米球在感染时可触发药物释放。合成了一种凝血酶敏感肽（TSP），并通过高效液相色谱法测定了凝血酶切割敏感性。结果显示，该肽与人血清接触时未发生切割，而与渗出液孵育时则被切割。随后，该肽通过EDC-NHS化学法与丝共聚物偶联，并制成包裹抗生素万古霉素的纳米球。对这些纳米球进行了体外感染响应型药物释放和抗菌活性评估。最后，在体内脓毒性关节炎模型中评估了药物响应型纳米球的疗效。我们的研究提供了证据，表明该蛋白质缀合物具有酶响应性，可用于制备靶向药物释放以对抗多重耐药细菌菌株的感染。
