34 Background: To establish NIR optical probe based on the HA-based supramolecular hydrogels (HASHs) conjugated with Cy5.5 for CD44-overexpressed gastric cancer imaging. Methods: To establish HASHs, Cy5.5 NHS ester was conjugated with polyethyleneimine (PEI, 25k Da) and mixed with hyaluronic acid (HA, 1M Da) by an electric interaction. The optimazed ideal molar ratio of PEI to HA was confirmed by DLS and gel electrophoresis. The CD44-expression level for various gastric cancer cell lInes (MKN1, MKN28, MKN45, MKN72, AGS, and N87 cells) was evaluated by FACS analysis. For establishment of the gastric cancer xenograft model, CD44-overexpressed gastric cancer cells were implanted into the BALB/c nude mouse's proximal thigh region. For in vitro targeting study, the cellular affinity of HASHs for CD44-low expressed gastric cancer cell line and CD44-overexpressed gastric cancer cell line was verified by confocal microscopy and IHC staing. For in vivo NIR imaging, HASHs were injected into established xenograft mouse via tail vein and NIR optical imaging was conducted time-dependently. Results: The colloidal size of HASHs was 1.4 micrometer and their morphology was confirmed by electron microscopy. CD44-expression level of MKN45 cells was 92.53% that was higher than MKN28 cells (2.66%). After the treatment of HASHs, the endocytosis into the cytosol was examined for MKN45 cells, but not observed in MKN28 cells due to the deficiency of CD44. 30 days after the transplantion of MKN45 cells, for in vivo imaging study, the prepared HASHs were intraveneously injected into tumor-bearing mouse model. By NIR optical imaging, the optical intensity at tumor site was enhanced upto 3 hours and the maximum intensity was 350 times larger than normal tissue. Conclusions: HASHs was established using supramolecular HA and Cy5.5-conjugated PEI for the targeted imaging of CD44-overexpressed gastric cancer cells. In vitro and in vivo studies demonstrated that SHAHs can visualize the individualized CD44-overexpressed gastric cancer cells by non-invasive optical imaging.
Constitutive Suppression of PRL-3 Inhibits Invasion and Proliferation of Gastric Cancer Cell in vitro and in vivo