Albumin-capped gold nanocluster-integrated human albumin scaffolds: a traceable, xeno-free and customizable template for autogenic tissue engineering applications

Albumin has attracted interest in the field of tissue engineering for fabricating three-dimensional scaffolds due to its stability, unique ligand-binding property, biocompatibility, high solubility and low cost. This study aimed to develop a versatile fluorescent scaffold using human serum albumin (HSA), HSA-capped gold nanoclusters (HSA@AuNCs) and oxidized dextran. The morphological, structural, mechanical and physical properties of the constructs were evaluated using FTIR, SEM, thermogravimetric analysis, swelling, compression, in vitro biocompatibility and degradation tests. Traceability was demonstrated by fluorescence imaging, while Au release from scaffolds was determined by inductively coupled plasma-optical emission spectroscopy. Cell adhesion and proliferation on scaffolds were evaluated using mesenchymal stem cells (MSCs), cellular metabolic activity was assessed by alamarBlue assay for 10 days. The alkaline phosphatase activity of MSCs was followed for up to 21 days. The findings revealed that the HSA/AuNC scaffolds are fluorescent, biodegradable and exhibit good in vitro biocompatibility. In addition, the nanocomposite scaffolds provide a suitable environment for MSCs to adhere, proliferate and maintain their metabolic activities. This work is expected to pave the way for the design of albumin-based scaffolds with different bioactive agents that can be conjugated to the albumin backbone.