Fmoc-PEG4-NHS ester

Immunochemotherapy combines a chemotherapeutic agent with an immune-modulating agent and represents an attractive approach to improve cancer therapy. However, the success of immunochemotherapy is hampered by the lack of a strategy to effectively co-deliver the two therapeutics to the tumours. Here we report the development of a dual-functional, immunostimulatory nanomicellar carrier that is based on a prodrug conjugate of PEG with NLG919, an indoleamine 2,3-dioxygenase (IDO) inhibitor currently used for reversing tumour immune suppression. An Fmoc group, an effective drug-interactive motif, is also introduced into the carrier to improve the drug loading capacity and formulation stability. We show that PEG2k-Fmoc-NLG alone is effective in enhancing T-cell immune responses and exhibits significant antitumour activity in vivo. More importantly, systemic delivery of paclitaxel (PTX) using the PEG2k-Fmoc-NLG nanocarrier leads to a significantly improved antitumour response in both breast cancer and melanoma mouse models.

A simple PEGylated peptidic nanocarrier, PEG5000-lysyl-(α-Fmoc-ε-Cbz-lysine)2 (PLFCL), was developed for effective co-delivery of doxorubicin (DOX) and dasatinib (DAS) for combination chemotherapy. Significant synergy of DOX and DAS in inhibition of cancer cell proliferation was demonstrated in various types of cancer cells, including breast, prostate, and colon cancers. Co-encapsulation of the two agents was facilitated by incorporation of 9-Fluorenylmethoxycarbonyl (Fmoc) and carboxybenzyl (Cbz) groups into a nanocarrier for effective carrier-drug interactions. Spherical nanomicelles with a small size of ∼30 nm were self-assembled by PLFCL. Strong carrier/drug intermolecular π-π stacking was demonstrated in fluorescence quenching and UV absorption. Fluorescence study showed more effective accumulation of DOX in nuclei of cancer cells following treatment with DOX&DAS/PLFCL in comparison with cells treated with DOX/PLFCL. DOX&DAS/PLFCL micelles were also more effective than other treatments in inhibiting the proliferation and migration of cultured cancer cells. Finally, a superior anti-tumor activity was demonstrated with DOX&DAS/PLFCL. A tumor growth inhibition rate of 95% was achieved at a respective dose of 5 mg/kg for DOX and DAS in a murine breast cancer model. Our nanocarrier may represent a simple and effective system that could facilitate clinical translation of this promising multi-agent regimen in combination chemotherapy.

Ibuprofen is a kind of nonsteroidal anti-inflammatory drug (NSAIDs), and it is considered to possess some antitumor effect. In this study, a novel nanomicellar carrier based on PEG-derivatized ibuprofen, PEG2K-Fmoc-Ibuprofen (PEG2K-FIbu), was developed for delivery of anticancer agents such as paclitaxel (PTX). This conjugate readily forms stable mixed micelles with PTX with a relatively high PTX loading capacity of 67%. The release of PTX from PTX-loaded PEG2K-FIbu micelles was significantly slower than that from Taxol formulation. PTX-loaded PEG2K-FIbu micelles and Taxol showed a comparable in vitro cytotoxicity. Importantly, PTX-loaded PEG2K-FIbu micelles demonstrated a much more pronounced in vivo therapeutic efficacy compared with Taxol with respect to both inhibition of tumor growth and animal survival. Our system may represent an attractive dual-functional delivery system to achieve synergistic activity with PTX while minimizing the carrier-associated toxicity.