The hepatitis B virus-like particle (HBV VLP) is an attractive protein nanoparticle platform due to the availability of 240 modification sites for engineering purposes. Although direct protein insertion into the surface loop has been demonstrated, this decoration strategy is restricted by the size of the inserted protein moieties. Meanwhile, larger proteins can be decorated using chemical conjugations; yet these approaches perturb the integrity of more delicate proteins and can unfavorably orient the proteins, impairing active surface display. Herein, we aim to create a robust and highly modular method to produce smart HBV-based nanodevices by using the SpyCatcher/SpyTag system, which allows a wide range of peptides and proteins to be conjugated directly and simply onto the modified HBV capsids in a controlled and biocompatible manner. Our technology allows the modular surface modification of HBV VLPs with multiple components, which provides signal amplification, increased targeting avidity, and high therapeutic payload incorporation. We have achieved a yield of over 200 mg/L for these engineered HBV VLPs and demonstrated the flexibility of this platform in both biosensing and drug delivery applications. The ability to decorate over 200 nanoluciferases per VLP improved detection signal by over 1500-fold, such that low nanomolar levels of thrombin could be detected by the naked eye. Meanwhile, a dimeric prodrug-activating enzyme was loaded without cross-linking particles by coexpressing orthogonally labeled monomers. This along with a epidermal growth factor receptor-binding peptide enabled tunable uptake of HBV VLPs into inflammatory breast cancer cells, leading to efficient suicide enzyme delivery and cell killing.

中文翻译：

---

用于生物传感和药物输送的模块化乙型肝炎病毒样颗粒平台。

由于有240个修饰位点可用于工程目的，因此乙型肝炎病毒样颗粒（HBV VLP）是有吸引力的蛋白质纳米颗粒平台。尽管已经证明了将蛋白质直接插入表面环中，但是这种修饰策略受到插入的蛋白质部分的大小的限制。同时，可以使用化学缀合修饰较大的蛋白质。然而，这些方法扰乱了更精致的蛋白质的完整性，并且可能不利地使蛋白质定向，从而损害了活性表面的展示。在本文中，我们旨在通过使用SpyCatcher / SpyTag系统创建一种可靠的，高度模块化的方法来生产基于HBV的智能纳米设备，该系统可将多种肽和蛋白质直接简单地偶联到修饰的HBV衣壳上和生物相容的方式。我们的技术允许对具有多种成分的HBV VLP进行模块化表面修饰，从而提供信号放大，增强的靶向亲和力和较高的治疗有效载荷掺入。这些工程学HBV VLP的产量已超过200 mg / L，并证明了该平台在生物传感和药物递送应用中的灵活性。每个VLP修饰200多种纳米荧光素酶的能力将检测信号提高了1500倍以上，从而可以用肉眼检测到低纳摩尔水平的凝血酶。同时，通过共表达正交标记的单体，装载了二聚体前药激活酶而没有交联颗粒。这与表皮生长因子受体结合肽一起使HBV VLP可调节地吸收到炎症性乳腺癌细胞中，