Inducing the formation of a colloidal albumin carrier of curcumin

The administration and delivery of pharmaceuticals faces a variety of well-known obstacles that result in limited biocompatibility and bioavailability. Efforts to improve these properties have often employed serum albumin, primarily due to its inherent biocompatibility and its ability to enhance the circulation times of pharmaceuticals. In this work, we have adapted a nanoparticle-formulation protocol, to produce a protein carrier of curcumin with bovine serum albumin. This was achieved by using a near-equimolar protein:curcumin ratio instead of the abundance of curcumin that would be normally used in a nanoparticle formulation. Photometric and quantitative analysis of this carrier showed an increased curcumin content in the produced aqueous solutions following the homogenization of bovine serum albumin (water) and curcumin (dichloromethane) phases. Albumin fluorescence studies indicated curcumin association near a tryptophan residue, without excluding the possibility of additional sites. Circular dichroism provided strong evidence of this association through the induced circular dichroism effect and showed that the secondary structure of bovine serum albumin was effectively maintained. Overall, this work presented a new means of facilitating the association of increased levels of curcumin with bovine serum albumin, which could potentially be used to generate additional non-covalent albumin carriers for pharmaceutical compounds.