Development of an embedded multimodality imaging platform for onco-pharmacology using a smart anticancer prodrug as an example

Combination of Targeted Therapies for Colorectal Cancer Treatment

The design of innovative therapeutic strategies enabling the selective destruction of tumor cells while sparing healthy tissues remains highly challenging in cancer therapy. Here, we show that the combination of two targeted therapies, including bevacizumab (Bev), and a β-glucuronidase-responsive albumin-binding prodrug of monomethyl auristatin E (MMAE), is efficient for the treatment of colorectal cancer implanted in mice. This combined therapy produces a therapeutic activity superior to that of the association of FOLFOX and Bev currently used to treat patients with this pathology. The increased anticancer efficacy is due to either a synergistic or an additive effect between Bev and MMAE selectively released from the glucuronide prodrug in the tumor microenvironment. Since numerous drug delivery systems such as antibody-drug conjugates employ MMAE as a cytotoxic payload, this finding may be of great interest for improving their therapeutic index by combining them with Bev, particularly for the therapy of colorectal cancer.

A β-Cyclodextrin-Albumin Conjugate for Enhancing Therapeutic Efficacy of Cytotoxic Drugs

Enhancing the selectivity of anticancer drugs currently used in the clinic is of great interest in order to propose more efficient chemotherapies with fewer side effects for patients. In this context, we developed a β-cyclodextrin trimer that binds to circulating albumin to form the corresponding bioconjugate in the bloodstream. This latter can then entrap doxorubicin following its i.v. administration via the formation of a host-guest inclusion complex and deliver the drug in tumors. In this study, we demonstrate that the β-cyclodextrin trimer improves the therapeutic efficacy of doxorubicin for the treatment of a subcutaneous murine Lewis lung carcinoma (LLC) implanted in C57BL/6 mice. This outcome is associated with an increased deposition of doxorubicin in malignant tissues when used in combination with the β-cyclodextrin trimer compared to the administration of the drug alone.

Validation of a combined ultrasound and bioluminescence imaging system with magnetic resonance imaging in orthotopic pancreatic murine tumors

Preclinical mouse solid tumor models are widely used to evaluate efficacy of novel cancer therapeutics. Recent reports have highlighted the need for utilizing orthotopic implantation to represent clinical disease more accurately, however the deep tissue location of these tumors makes longitudinal assessment challenging without the use of imaging techniques. The purpose of this study was to evaluate the performance of a new multi-modality high-throughput in vivo imaging system that combines bioluminescence imaging (BLI) with robotic, hands-free ultrasound (US) for evaluating orthotopic mouse models. Long utilized in cancer research as independent modalities, we hypothesized that the combination of BLI and US would offer complementary advantages of detection sensitivity and quantification accuracy, while mitigating individual technological weaknesses. Bioluminescent pancreatic tumor cells were injected into the pancreas tail of C57BL/6 mice and imaged weekly with the combination system and magnetic resonance imaging (MRI) to serve as a gold standard. BLI photon flux was quantified to assess tumor activity and distribution, and US and MRI datasets were manually segmented for gross tumor volume. Robotic US and MRI demonstrated a strong agreement (R2 = 0.94) for tumor volume measurement. BLI showed a weak overall agreement with MRI (R2 = 0.21), however, it offered the greatest sensitivity to detecting the presence of tumors. We conclude that combining BLI with robotic US offers an efficient screening tool for orthotopic tumor models.

Membrane-destabilizing ionizable lipid empowered imaging-guided siRNA delivery and cancer treatment

One of the imperative medical requirements for cancer treatment is how to establish an imaging-guided nanocarrier that combines therapeutic and imaging agents into one system. siRNA therapeutics have shown promising prospects in controlling life-threatening diseases. However, it is still challenging to develop siRNA formulations with excellent cellular entry capability, efficient endosomal escape, and simultaneous visualization. Herein, we fabricated multifunctional ionizable lipid nanoparticles (iLNPs) for targeted delivery of siRNA and MRI contrast agent. The iLNPs comprises DSPC, cholesterol, PEGylated lipid, contrast agent DTPA-BSA (Gd), and ionizable lipid termed iBL0104. siRNA-loaded iLNPs (iLNPs/siRNA) could be decorated with a tumor targeting cyclic peptide (c(GRGDSPKC)) (termed GARP), or without targeting modification (termed GAP). Data revealed that GARP/siRNA iLNPs exhibited significantly higher cellular entry efficiency than GAP/siRNA iLNPs. GARP/siRNA iLNPs rapidly and effectively escaped from endosome and lysosome after internalization. Compared with GAP/siPLK1, GARP/siPLK1 exhibited better tumor inhibition efficacy in both cell-line derived xenograft and liver cancer patient derived xenograft murine models. In addition, GARP formulation displayed ideal MRI effect in tumor-bearing mice, and was well tolerated by testing animals. Therefore, this study provides an excellent example for achieving imaging-guided and tumor-targeted siRNA delivery and cancer treatment, highlighting its promising potential for translational medicine application.