Work

Chaperone/Polymer Complexation of Protein-Based Fluorescent Nanoclusters against Silica Encapsulation-Induced Physicochemical Stresses

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Silica encapsulation under ambient conditions is commonly used to shield protein-based nanosystems from chemical stress. However, encapsulation-induced photo- and structural instabilities at elevated temperatures have been overlooked. Using bovine serum albumin-capped fluorescent gold nanoclusters (BSA–AuNCs) as a model, we demonstrated that chaperone/polymer layer-by-layer complexation can stabilize the template to resist encapsulation-induced fragmentation/reorganization and emission increases at 37 °C or higher temperatures. We first wrapped BSA–AuNCs with α-crystallin chaperones (α-Crys) to gain the highest thermal stability at a 1:50 molar ratio and then enfolded BSA–AuNC/α-Crys with thermoresponsive poly- N -isopropylacrylamide (PNIPAM) at 60 °C to shield silica interaction and increase the chaperone–client protein accessibility. The resulting BSA–AuNC/α-Crys/PNIPAM (BαP) was encapsulated by a sol–gel process to yield BαP–Si (∼80 ± 4.5 nm), which exhibited excellent structural integrity and photostability against chemical and thermal stresses. Moreover, targeted BαP–Si demonstrated prolonged fluorescence stability for cancer cell imaging. This template stabilization strategy for silica encapsulation is biocompatible and applicable to other protein-based nanosystems.

Source: Biomacromolecules

DOI: 10.1021/acs.biomac.4c00689