Harnessing Biology to Deliver Therapeutic and Imaging Entities via Cell‐Based Methods

Abstract

The accumulation of therapeutic and imaging agents at sites of interest is critical to their efficacy. Similarly, off-target effects (especially toxicity) are a major liability for these entities. For this reason, the use of delivery vehicles to improve the distribution characteristics of bio-active agents has become ubiquitous in the field. However, the majority of traditionally employed, cargo-bearing platforms rely on passive accumulation. Even in cases where “targeting” functionalities are used, the agents must first reach the site in order for the ligand–receptor interaction to occur. The next stage of vehicle development is the use of “recruited” entities, which respond to biological signals produced in the tissues to be targeted, resulting in improved specificities. Recently, many advances have been made in the utilization of cells as delivery agents. They are biocompatible, exhibit excellent circulation lifetimes and tissue penetration capabilities, and respond to chemotactic signals. In this Minireview, we will explore various cell types, modifications, and applications where cell-based delivery agents are used.

Surface-Modified Macrophages Facilitate Tracking of Breast Cancer-Immune Interactions

“…13 But because macrophages and their monocyte precursors are actively recruited to cancerous tissues, 14 they have also become candidates for use as imaging and therapeutic agent delivery vehicles. 15 A number of tumor types secrete the major macrophage chemoattractants macrophage colony stimulating factor (M-CSF, also known as colony stimulating factor 1, or CSF-1) 16 and monocyte chemoattractant protein like chemokine (C–C motif) ligand 2 (CCL2). 17 Once in the tumor microenvironment, TAMs can traffic into difficult-to-reach hypoxic regions, 14 areas that are problematic to target with other therapeutic delivery systems.…”

“…On account of their roles in cancer progression and metastasis, TAMs have become a target of interest for developing new treatments . But because macrophages and their monocyte precursors are actively recruited to cancerous tissues, they have also become candidates for use as imaging and therapeutic agent delivery vehicles . A number of tumor types secrete the major macrophage chemoattractants macrophage colony stimulating factor (M-CSF, also known as colony stimulating factor 1, or CSF-1) and monocyte chemoattractant protein like chemokine (C–C motif) ligand 2 (CCL2) .…”

Chemically Engineered Immune Cell‐Derived Microrobots and Biomimetic Nanoparticles: Emerging Biodiagnostic and Therapeutic Tools

“…Recently, dendritic cells (DCs), macrophages (M ϕ s), monocytes (MCs), neutrophils (NEs), and lymphocytes, especially T cells (TCs) have attracted the most scientific attention for this goal. [ 14 ] In this regard, the following sections offer a review of the literature focused on alive immune cells applied as therapeutic carriers to treat various diseases.…”

“…[ 88 ] Nongenetic approaches include inserting specific molecules or particles on the cell surface through noncovalent binding (e.g., electrostatic interaction, lipids with or without hydrophilic heads being anchored on the cell membrane, receptor–ligand interactions, and antibody–antigen interactions), covalent bindings (e.g., biotin–avidin interaction, N ‐hydroxy succinimide (NHS) esters–maleimides coupling, and click chemistry reactions like azide–alkyne conjugation), or even membranous fusion with engineered liposomes. [ 14a,37,87b,88,89 ] The following sections will focus on surface‐engineered immune cells and their advantages in preclinical and clinical subsets.…”

Re‐engineered imaging agent using biomimetic approaches

“…In comparison to conventional encapsulation strategy, the surface modification technique offers advantages in many regards. The coupling of contrast agent onto cell can reduce harsh condition that cells have to undergo to facilitate loading of cargo into intracellular compartment (Joshi et al, 2018). In addition, the attached amount and release of the agent after engineering into cell carrier can also be controlled by changing the feed amount and chemicals affinity of the linker (Joshi et al, 2018).…”