Search

Albumin, the most abundant protein in human serum, is applied to various diseases as a drug delivery carrier because of its superior blood retention, high biocompatibility, and a wide variety of drug binding abilities. Albumin is known to distribute widely in the blood and various interstitial fluids and organs. Different albumin receptors skillfully regulate the distribution characteristics of albumin in the body. Albumin receptors are a group of diverse proteins, such as FcRn, gp60, gp18, megalin, cubilin, SPARC, and CD36. Their tissue distributions in vivo are unique, with different albumin's recognition sites. Therefore, the distribution of albumin in vivo is ingeniously controlled by these multiple albumin receptors. Reevaluation of these albumin receptors opens up new possibilities for applying albumin as a drug delivery carrier. If the tissue distributions of albumin receptors were known and the albumin recognition site of the receptor was identified, organ-specific active targeting would be possible. In this review, we would like to scrutinize what is currently known and share information to develop next-generation albumin carriers that focus on interactions with albumin receptors.

Lactoferrin (Lf) nanoparticles have been developed as a carrier of drugs and gene. Two main methods, desolvation technique and emulsification method, for preparation of protein nanoparticles have been reported so far, but most of the previous reports of Lf nanoparticles preparation are limited to emulsification method. In this study, we investigated the optimal conditions by desolvation technique for the preparation of glutaraldehyde-crosslinked bovine Lf (bLf) nanoparticles within the size range of 100-200 nm, and evaluated their properties as a carrier for oral and intravenous drug delivery. The experimental results of dynamic light scattering and Transmission Electron Microscope suggested that glutaraldehyde-crosslinked bLf nanoparticles with 150 nm in size could be produced by addition of 2-propanol as the desolvating solvent into the bLf solution adjusted to pH 6, followed by crosslinking with glutaraldehyde. These cross-linked bLf nanoparticles were found to be compatible to blood components and resistant against rapid degradation by pepsin. Thus, cross-linked bLf nanoparticles prepared by desolvation technique can be applied as a drug carrier for intravenous administration and oral delivery.