Abstract Interaction at the interface between protein and nanoparticle (NP) surface is of fundamental importance in nanomedicine, because protein corona formation on the NP surface affects the biological identity of the NP. Recently, polyglycerol (PG) has been revealed as a protein free coating for NPs, enabling us to evaluate the net affinity of the specific functional group on the “transparent” NP surface to protein. Herein, PG grafted nanodiamond (ND-PG) was functionalized with carboxyl and amino groups at various densities, and their interaction with proteins including lysozyme (LYS), bovine serum albumin (BSA) and γ-globulin (γ-GLO) were investigated in phosphate buffer saline (PBS). The results show that the carboxylate (-COO–) and ammonium (-NH3+) groups interact exclusively with positively charged LYS, and negatively charged BSA and γ-GLO, respectively, and that the interaction becomes stronger as the functional group density increases. Moreover, the association constants (K) between BSA and the ammonium group on ND-PG are determined and found to correlate linearly with the ammonium group density. The slopes in the linear relationship are proposed to be indices to represent the interaction strength of ammonium group to BSA, enabling the quantitative comparison of the affinity between proteins and various NP surface coatings.

中文翻译：

---

聚甘油接枝纳米金刚石表面蛋白质与带电官能团相互作用的定量研究

摘要 蛋白质和纳米颗粒 (NP) 表面之间界面处的相互作用在纳米医学中至关重要，因为 NP 表面上的蛋白质电晕形成会影响 NP 的生物学特性。最近，聚甘油 (PG) 已被揭示为 NP 的无蛋白质涂层，使我们能够评估“透明”NP 表面上特定官能团对蛋白质的净亲和力。在此，PG 接枝纳米金刚石 (ND-PG) 被不同密度的羧基和氨基官能化，并研究了它们与溶菌酶 (LYS)、牛血清白蛋白 (BSA) 和 γ-球蛋白 (γ-GLO) 等蛋白质的相互作用。磷酸盐缓冲盐水 (PBS)。结果表明，羧酸根 (-COO-) 和铵 (-NH3+) 基团仅与带正电的 LYS、带负电的 BSA 和 γ-GLO 相互作用，分别，并且随着官能团密度的增加，相互作用变得更强。此外，测定了 BSA 与 ND-PG 上的铵基团之间的缔合常数 (K)，发现它与铵基团密度呈线性相关。线性关系中的斜率被提议作为表示铵基团与 BSA 相互作用强度的指标，从而能够定量比较蛋白质与各种 NP 表面涂层之间的亲和力。