ECM Depletion Is Required to Improve the Intratumoral Uptake of Iron Oxide Nanoparticles in Poorly Perfused Hepatocellular Carcinoma.

Yen Ling Yeow,Janina E E Tirnitz-Parker,Kirk W Feindel,Peter J Leedman,Juliana Hamzah,Ruth Ganss,Xiao Wang,Louise Winteringham,Jiansha Wu

doi:10.3389/fonc.2022.837234

Abstract

Improving tumor access for drug delivery is challenging, particularly in poorly perfused tumors. The availability of functional tumor blood vessels for systemic access is vital to allow drugs or imaging agents to accumulate in the tumor parenchyma. We subjected mice engineered to develop hepatocellular carcinoma (HCC), to treatment with tumor necrosis factor alpha (TNFα) conjugated to a CSG peptide (CSGRRSSKC). CSG binds to the laminin-nidogen-1 complex of the extracellular matrix (ECM) in HCC. When produced as a recombinant fusion protein, the TNFα-CSG functions as an ECM depletion agent via an immune-mediated mechanism to improve tumor perfusion. Tumor perfusion in HCC was dramatically improved after daily intravenous (i.v.) injection of 5 µg TNFα-CSG for five consecutive days. Following treatment, we assessed the tumor accessibility to accumulate an imaging agent, superparamagnetic iron-oxide nanoparticles (IO-NP). Here, we compared the passive delivery of an i.v. dose of IO-NP in HCC following ECM depletion after TNFα-CSG treatment, to the intratumoral accumulation of a comparable dose of CSG-targeted IO-NP in HCC with intact ECM. Magnetic resonance imaging (MRI) T2-weighted scans and T2 relaxation times indicate that when the tumor ECM is intact, HCC was resistant to the intratumoral uptake of IO-NP, even when the particles were tagged with CSG peptide. In contrast, pre-treatment with TNFα-CSG resulted in the highest IO-NP accumulation in tumors. These findings suggest poorly perfused HCC may be resistant to molecular-targeted imaging agents including CSG-IO-NP. We demonstrate that specific ECM depletion using TNFα-CSG improves nanoparticle delivery into poorly perfused tumors such as HCC.

Highlights

Systemic delivery of therapeutics and imaging agents in tumors relies primarily on accessibility via tumor blood vessels [1]
We first evaluated blood vessel functionality in albumin gene promoter (ALB)-T antigen (Tag) hepatocellular carcinoma (HCC) in comparison with pancreatic neuroendocrine tumors (PNET) in RIP1-Tag5 mice using i.v.-injected lectin binding to blood vessels as a surrogate marker for tumor perfusion
Our study demonstrates that whilst enhanced permeability and retention (EPR) may be sufficient for some small drug molecules to penetrate solid tumors, poorly perfused tumors may remain inaccessible for larger molecules, including nanoparticles such as iron-oxide nanoparticles (IO-NP)

Summary

Introduction

Systemic delivery of therapeutics and imaging agents in tumors relies primarily on accessibility via tumor blood vessels [1]. The passive delivery of non-targeted agents in tumors is based on the enhanced permeability and retention (EPR) effect of leaky tumor vasculature, resulting in higher accumulation in tumors than in normal tissues [2]. This passive delivery via the EPR effect is insufficient to allow macromolecules and nanoparticles to extravasate and accumulate in the parenchyma of solid tumors [3]. Ligands with specific binding affinity to unique molecular tumor targets have been developed for the delivery of therapeutic and imaging payloads including nanoparticle-based contrast agents [4]. When CSG is linked to superparamagnetic iron-oxide nanoparticles (IO-NP), CSG-IO-NP accumulate selectively in the stromal ECM, for instance in pancreatic neuroendocrine tumors (PNET) [6]

Methods

Results

Conclusion