Advancing Medical Applications of Cancer Nanotechnology: Highlighting Two Decades of the NCI'S Nanotechnology Characterization Laboratory Service to the Research Community.

The Nanotechnology Characterization Laboratory (NCL) is a US federally funded resource providing characterization and expertise to the cancer nanomedicine research community. Founded as a formal partnership among the US National Cancer Institute (NCI), the US Food and Drug Administration (FDA), and the US National Institute of Standards and Technology (NIST), the NCL has spent two decades developing a one-of-a-kind service with broad multidisciplinary expertise to meet the needs of a rapidly evolving drug development field. To mark the 20th anniversary of the lab's founding, the NCL hosted a symposium to highlight the achievements of the cancer nanomedicine field, showcase novel, next-generation nanotechnology research, and discuss future priorities to enable continued growth in combating cancer and the complexities associated with treating a disease that continues to take millions of lives annually.

A translational framework to DELIVER nanomedicines to the clinic.

Nanomedicines have created a paradigm shift in healthcare. Yet fundamental barriers still exist that prevent or delay the clinical translation of nanomedicines. Critical hurdles inhibiting clinical success include poor understanding of nanomedicines' physicochemical properties, limited exposure in the cell or tissue of interest, poor reproducibility of preclinical outcomes in clinical trials, and biocompatibility concerns.

Mannose-modified hyaluronic acid nanocapsules for the targeting of tumor-associated macrophages.

Tumor-associated macrophages (TAMs), a class of immune cells that play a key role in tumor immunosuppression, are recognized as important targets to improve cancer prognosis and treatment. Consequently, the engineering of drug delivery nanocarriers that can reach TAMs has acquired special relevance. This work describes the development and biological evaluation of a panel of hyaluronic acid (HA) nanocapsules (NCs), with different compositions and prepared by different techniques, designed to target macrophages.

Delivering the power of nanomedicine to patients today.

The situation of the COVID-19 pandemic reminds us that we permanently need high-value flexible solutions to urgent clinical needs including simplified diagnostic technologies suitable for use in the field and for delivering targeted therapeutics. From our perspective nanotechnology is revealed as a vital resource for this, as a generic platform of technical solutions to tackle complex medical challenges. It is towards this perspective and focusing on nanomedicine that we take issue with Prof Park's recent editorial published in the Journal of Controlled Release.

A Nanoprimer To Improve the Systemic Delivery of siRNA and mRNA.

Despite tremendous interest in gene therapies, the systemic delivery of nucleic acids still faces substantial challenges. To successfully administer nucleic acids, one approach is to encapsulate them in lipid nanoparticles (LNPs). However, LNPs administered intravenously substantially accumulate in the liver where they are taken up by the reticuloendothelial system (RES).

Priming the body to receive the therapeutic agent to redefine treatment benefit/risk profile.

Many therapeutic agents offer a low useful dose (dose responsible for efficacy)/useless dose (dose eliminated or responsible for toxicity) ratio, mainly due to the fact that therapeutic agents must ensure in one single object all the functions required to deliver the treatment, which leads to compromises in their physico-chemical design. Here we introduce the concept of priming the body to receive the treatment by uncorrelating these functions into two distinct objects sequentially administered: a nanoprimer occupying transiently the main pathway responsible for therapeutic agent limited benefit/risk ratio followed by the therapeutic agent. The concept was evaluated for different nature of therapeutic agents: For nanomedicines we designed a liposomal nanoprimer presenting preferential hepatic accumulation without sign of acute toxicity.

Nano-sized cytochrome P450 3A4 inhibitors to block hepatic metabolism of docetaxel.

Most drugs are metabolized by hepatic cytochrome P450 3A4 (CYP3A4), resulting in their reduced bioavailability. In this study, we present the design and evaluation of bio-compatible nanocarriers trapping a natural CYP3A4-inhibiting compound. Our aim in using nanocarriers was to target the natural CYP3A4-inhibiting agent to hepatic CYP3A4 and leave drug-metabolizing enzymes in other organs undisturbed.

A new opportunity for nanomedicines: Micellar cytochrome P450 inhibitors to improve drug efficacy in a cancer therapy model.

Nanomedicines are mainly used as drug delivery systems; here we evaluate a new application - to inhibit a drug's metabolism thereby enhancing its effective dose. Micelles containing the natural furanocoumarin 6',7'-dihydroxybergamottin (DHB), a known CYP450 inhibitor, were developed to transiently block hepatic CYP450-mediated drug metabolism and increase the bioavailability of the oncology drug docetaxel. Administered in mice 24h prior to the drug, DHB-micelles enhanced antitumor efficacy in the tumor xenograft models HT-29 and MDA-MB-231, when compared to the drug alone.

MRI contrast variation of thermosensitive magnetoliposomes triggered by focused ultrasound: a tool for image-guided local drug delivery.

Improved drug delivery control during chemotherapy has the potential to increase the therapeutic index. MRI contrast agent such as iron oxide nanoparticles can be co-encapsulated with drugs in nanocarrier liposomes allowing their tracking and/or visualization by MRI. Furthermore, the combination of a thermosensitive liposomal formulation with an external source of heat such as high intensity focused ultrasound guided by MR temperature mapping allows the controlled local release of the content of the liposome.

One pot synthesis of new hybrid versatile nanocarrier exhibiting efficient stability in biological environment for use in photodynamic therapy.

A new versatile hybrid nanocarrier has been designed using a "soft chemistry" synthesis, to efficiently encapsulate a photosensitizer - the protoporphyrin IX (Pp IX) - while preserving its activity intact in biological environment for advantageous use in photodynamic therapy (PDT). The synthesized Pp IX silica-based nanocarriers show to be spherical in shape and highly monodisperse with size extending from 10 nm up to 200 nm according to the synthesis procedure. Upon laser irradiation, the entrapped Pp IX shows to efficiently deliver reactive oxygen species (ROS) which are responsible for damaging tumor tissues.

Pp IX silica nanoparticles demonstrate differential interactions with in vitro tumor cell lines and in vivo mouse models of human cancers.

Protoporphyrin IX (Pp IX) silica nanoparticles, developed for effective use in photodynamic therapy (PDT), were explored in in vitro and in vivo models with the ambition to improve knowledge on the role of biological factors in the photodamage. Pp IX silica nanoparticles are found efficient at temperature with extreme metabolic downregulation, which suggest a high proportion of passive internalization. For the first time, clearance of silica nanoparticles on tumor cells is established.

Protection of mammalian cell used in biosensors by coating with a polyelectrolyte shell.

In order to detect xenoestrogens which induce perturbations of mammalian cells, design of biosensor using a mammalian cell line enable to detect these compounds is necessary. MELN cell line is suitable to detect estrogen activity, since they are stably transfect with an estrogen regulated luciferase gene. To realize this biosensor, it appeared necessary to add a protection to the mamalian cell, which is devoided, of the wall protecting yeasts or plant cells.

Liposome-based nanocapsules.

Here we present three different types of mechanically stable nanometer-sized hollow capsules. The common point of the currently developed systems in our laboratory is that they are liposome based. Biomolecules can be used to functionalize lipid vesicles to create a new type of intelligent material.

Inactivation of the 3'-5' exonuclease of the replicative T4 DNA polymerase allows translesion DNA synthesis at an abasic site.

Here, we have investigated the consequences of the loss of proof-reading exonuclease function on the ability of the replicative T4 DNA polymerase (gp43) to elongate past a single abasic site located on model DNA substrates. Our results show that wild-type T4 DNA polymerase stopped at the base preceding the lesion on two linear substrates having different sequences, whereas the gp43 D219A exonuclease-deficient mutant was capable of efficient bypass when replicating the same substrates. The structure of the DNA template did not influence the behavior of the exonuclease-proficient or deficient T4 DNA polymerases.