Development and Pharmacokinetics of Galactosylated Poly-L-Glutamic Acid as a Biodegradable Carrier for Liver-Specific Drug Delivery

Purpose. A biodegradable carrier for the liver-specific delivery of drugs was developed using poly-L-glutamic acid (PLGA) modified with galactose (galactosylated PLGA or Gal-PLGA), and its feasibility was investigated in mice.Methods. ¹¹¹In-PLGA and ¹¹¹In-Gal-PLGAs were injected in mice and their distribution and biodegradation properties were studied.Results. After intravenous injection, ¹¹¹In-PLGA was rapidly eliminated from the plasma and recovered mainly in the kidneys and urine. Approximately 15% of the dose was recovered in the liver, predominantly in the nonparenchymal cells. ¹¹¹In-Gal-PLGAs were taken up by the liver parenchymal cells. Derivatives having 16 or more galactose residues were taken up by the liver to a higher extent (>60% of the dose). The hepatic clearance of ¹¹¹n-Gal-PLGAs correlated with their number of galactose residues. ¹¹¹In-Gal₁₈-PLGA was degraded into low-molecular weight products in the liver.Conclusions. The advantageous in vivo properties of Gal-PLGA as a liver-specific biodegradable carrier of drugs were demonstrated in mice.