Au3+-mediated high-density lipoprotein crosslinking: from microgels in all-aqueous emulsions to 3D structures by printing

Summary

This thesis presents a simple method to fabricate HDL microgels of various shapes through protein oxidation and Au³⁺–initiated crosslinking in the droplet phase of all aqueous emulsions—spherical and urchin-like microgels formed under different pH and protein concentrations. The spherical microgels were selected to study the effect of visible light intensity on crosslinking rate, size, shape, and structure. Visible light accelerated di-tyrosine-mediated crosslinking at high light intensity. Using Rhodamine B as a drug model, different factors that influence uptake and release properties were explored, indicating that temperature was identified as the key factor for uptake, while ionic strength most influenced release. Additionally, Au³⁺ solution could be hand-injected into HDL solutions to form hybrid gels, with visible light further accelerating gelation, which achieves liquid-liquid 3D printing by hand. Future studies should explore other (bio)polymers and crosslinking systems, broadening their applications in drug delivery, 3D bioprinting, nanoreactors, and catalysis.