title: In situ cross-linkable high molecular weight hyaluronan-bisphosphonate conjugate for localized delivery and cell-specific targeting: a hydrogel linked prodrug approach.
abstract: We present here a novel synthesis route to functionalize high molecular weight hyaluronan (HMW-HA) with a hydrazide group and a bioactive ligand, namely bisphosphonate (BP). For this purpose, a new symmetrical self-immolative biscarbazate linker has been devised. The hydrazide group was used to form hydrazone cross-linked hydrogel upon treating with previously described aldehyde modified hyaluronan. The 1:1 weight ratio of these two polymers gave hydrogel in less than 30 s. In this communication we present the first in vitro results showing that even though HA can target CD44 positive cancer cells (HCT-116), receptor mediated endocytosis could only occur by cleavage of high molecular weight HA with an ubiquitous enzyme, hyaluronidase (Hase). The cancer cells are known to overexpress CD44 receptors and also increase the hyaluronidase activity in vivo. Thus the pro-drug design, based on drug conjugation to HMW-HA, represents a new drug delivery platform where the drug potency is triggered by Hase mediated degradation of the HA-drug conjugate. We have successfully demonstrated that the cross-linkable HA-BP conjugate first undergoes Hase-mediated scission to the fragments of suitable sizes so as to be internalized by CD44 positive cells. The specificity of this targeting was proven by comparing the results with less CD44 positive HEK-293T cells. The localized delivery of such drugs at the surgical resection site opens up avenues to control tumor recurrence after removal of the tumor. In the form of hydrogel it would prevent systemic exposure of the drug and would allow its controlled release.
authors.affiliation: Material Chemistry Department, Uppsala University, Angstrom Laboratory, S-75121 Uppsala, Sweden.
authors.forename: Oommen P
authors.initials: OP
authors.lastname: Varghese
authors.forename: Weilun
authors.initials: W
authors.lastname: Sun
authors.forename: Jöns
authors.initials: J
authors.lastname: Hilborn
authors.forename: Dmitri A
authors.initials: DA
authors.lastname: Ossipov
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000378:metabolism; D004164:Diphosphonates / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D006821:Hyaluronoglucosaminidase / Q000378:metabolism; D006834:Hydrazines / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D007668:Kidney / Q000166:cytology; D011355:Prodrugs / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity
chemical_list: D000970:Antineoplastic Agents; D004164:Diphosphonates; D004337:Drug Carriers; D018960:Hyaluronan Receptors; D006834:Hydrazines; D011355:Prodrugs; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006820:Hyaluronic Acid; D006821:Hyaluronoglucosaminidase