This invention discloses a pH-responsive
nanodiamond drug delivery system and its preparation method, belonging to the field of
nanomedicine carrier technology. The
delivery system uses polyglycerol-modified
nanodiamond (NDPG) as the base carrier, covalently loading
doxorubicin (DOX) via pH-sensitive
hydrazone bonds, and combining it with
hyaluronic acid (HA) to achieve
targeted modification and surface-stabilized
coating, ultimately forming an HA-DOX / NDPG composite
system or an NDPG-DOX@HA core-shell structure. The preparation method includes: in-situ ring-opening
polymerization grafting of polyglycerol onto the
nanodiamond surface to obtain NDPG; activation of
hyaluronic acid followed by
coupling with
adipic acid dihydrazide, then forming
hydrazone bonds with
doxorubicin to obtain HA-DOX; activation of NDPG followed by
grafting of connecting arms, then
coupling with
doxorubicin to obtain NDPG-DOX, and finally
coating with
hyaluronic acid to obtain the core-shell product. The carrier of this invention exhibits good water dispersibility, stable
drug loading rate, low
drug leakage under physiological conditions, rapid
drug release in the weakly acidic environment of tumors, and also possesses active targeting capability and good
biocompatibility. It can be used to prepare highly effective and low-
toxicity antitumor drugs, and has high clinical application and translational value.