Enhanced Biorecognition and Internalization of HPMA Copolymers Containing Multiple or Multivalent Carbohydrate Side-Chains by Human Hepatocarcinoma Cells

Abstract

N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers containing pendant saccharide moieties (galactosamine, lactose, and triantennary galactose) were synthesized. The relationship between the content of saccharide moieties and three-dimensional arrangement of galactose residues and their biorecognition and internalization by human hepatocarcinoma HepG2 cells was investigated. The results obtained clearly indicated preferential binding of the trivalent galactose and the lactose-containing copolymers to these cells. The higher the saccharide moieties content in HPMA copolymers, the higher the levels of binding. The biorecognition of the glycosylated HPMA copolymers by HepG2 cells was inhibited by free lactose. The data on the internalization and subcellular trafficking of HPMA copolymer conjugates obtained by confocal fluorescence microscopy correlated well with the flow cytometric analysis of their biorecognition by target cells. Structural features of the glycosides responsible for the specific recognition of the HPMA copolymers have been identified. The results underline the potential of glycosylated HPMA copolymers for delivery of pharmaceutical agents to hepatocarcinoma cells.

The cytoplasmic escape and nuclear accumulation of endocytosed and microinjected HPMA copolymers and a basic kinetic study in hep G2 cells

“…A basic study of the rate of internalization revealed that the targeted polymer was internalized at a rate almost 2 orders of magnitude faster than that of the nontargeted polymer P2 (Figure 4). It should be noted that the recent data by David et al (30) indicate that even more dramatic differences in uptake should be possible using polymer with higher amounts of trivalent galactose.…”

“…Increasing the galactose content of the polymer was recently reported to increase the internalization of HPMA copolymer in Hep G2 cells (30). The targeted polymer P1 tested in this work contained 14 mol% of galactosecontaining monomers.…”

“…Although there have been studies demonstrating the ability of HPMA copolymers to be targeted to hepatocytes in vivo (1,3) and in vitro (30,39) using galactose, the kinetics of internalization were not evaluated. In a concentration-dependent internalization study (Figure 3), the nontargeted polymer P2 showed a linear dose response curve expected for fluid-phase pinocytosis of macromolecules.…”

Tumor targeting HPMA-porphyrin-99mTc copolymer molecular imaging agent

“…By the end of the 30-min incubation, binding approached saturation with 41.77% of the initial radioactivity, indicating that the cancer cells-mediated endocytosis of targeted poly(HPMA)-porphyrin-DTPA-99m Tc tracer by H22 cells. [28] Interestingly, the maximal uptake of poly(HPMA)-DTPA-99m Tc (nontargeted binding) also reached 16.40% of the total conjugate added due to the EPR effect. As controls, DTPA-99m Tc lacking the porphyrin group and passive-targeted HPMA polymeric carrier did not show any significant cell association ( Figure 2) (2.98%).…”

Fabrication of novel hepatoma-targeting microdisks by hydrogen bond-assisted self-assembly of an azacitidine-conjugating amphiphilic random copolymer

“…the resulting azacitidine-containing polymers [30]. Herein, polymerizable galactose mono-ester VGA was chosen as the comonomer because the galactose moiety could be employed as a targeting ligand to mediate drug to liver parenchymal cells [31]. VGA could be easily obtained by the same method as the preparation of VAC [27].…”