Effect of UV-curable and injectable dendrimer matrix on tumor pharmacokinetics and survival in a hepatocellular carcinoma mouse model using interstitial photodynamic therapy.

Abstract

e15598 Background: Intratumoral drug delivery in cancer treatment has shown to increase drug accumulation in tumors and decrease adverse effects of systemic therapies. The active agent is typically required to stay in contact with the tumor and thus attachment directly into the tumor or to the surrounding tissue is warranted. In addition, a long-acting release of the active drug is vital. Dendrimers are nano-sized, radially symmetric molecules with homogeneous and monodisperse structures, which can used to encapsulate drug molecules for controlled release with the aid of external stimuli at physiological pH. Methods: We prepared a dendrimeric drug delivery matrix based on a PEG-core. The model drug (5-fluorouracil or doxorubicin) was covalently bonded to the core. The release of the drug was observed up to 29 days in vitro. The outer shell of the matrix was partially modified to obtain a fast UV-curing and subsequent attachment to the tumor tissue utilizing interstitial photodynamic therapy. We compared the pharmacokinetics, tissue distribution and antitumor efficacy of conventional systemic therapy and the intratumoral therapy in xenograft-bearing mice. In addition, we monitored blood parameters and body weight of the animals for adverse effects. Results: The dendrimer matrix caused significantly greater inhibition of human hepatocellular carcinoma xenograft tumor growth when compared with systemic therapy, without increasing toxicity. The matrix enabled a significant increase in drug accumulation in tumors, and markedly extended the survival of mice compared with systemic treatments. A larger decrease in blood parameters as well as spleen weight was observed in the systemic therapy group especially when using 5-fluorouracil. Conclusions: Our study shows that the intratumoral treatment strategy based on a novel UV-curable dendrimer hydrogel matrix enhances antitumor activity by improving pharmacokinetics and drug accumulation and increases efficacy in comparison to conventional systemic therapy. These results highlight the potential use of dendrimer hydrogels in the treatment of hepatocellular carcinoma.