Functionalized Alpha-lactalbumin Conjugated with Gold Nanoparticle for Targeted Drug Delivery

The protein-nanoparticles conjugate has been developed as a targeted drug delivery system which selectively and preferentially delivers the therapeutic agents. Here, the alpha-lactalbumin (ALA) was purified by size exclusion chromatography and confirmed by gel electrophoresis and mass spectrometry (MS). Functionalization of gold nanoparticles (AuNP, similar to 29 nm) with ALA was optimized by light scattering and zeta potential measurements. The nanoconjugates (AuNP-ALA) and ALA showed strong binding and affinity with curcumin and gemcitabine studied using biophysical analysis. The presence of native form of curcumin with ALA was investigated by MS. 8-anilino-1-naphthalenesulfonic acid binding assay showed 95 % surface hydrophilicity of ALA. Circular dichroism and Fourier transform infrared spectroscopy analysis shows increased alpha-helicity due to the binding of drugs, revealed large increase in non-covalent interaction. Vesicular membrane interaction with ALA and nanoconjugate exhibited strong interaction at the vesicles surface. The alpha-lactalbumin-nanoparticle conjugate in combination with drugs, could be exploited to establish a targeted drug delivery system.