Overcoming Biological Barriers With Block Copolymers-Based Self-Assembled Nanocarriers. Recent Advances in Delivery of Anticancer Therapeutics

Abstract

Cancer is one of the most common life-threatening illness and it is the world’s second largest cause of death. Chemotherapeutic anticancer drugs have many disadvantages, which led to the need to develop novel strategies to overcome these shortcomings. Moreover, tumors are heterogenous in nature and there are various biological barriers that assist in treatment reisistance. In this sense, nanotechnology has provided new strategies for delivery of anticancer therapeutics. Recently, delivery platforms for overcoming biological barriers raised by tumor cells and tumor-bearing hosts have been reported. Among them, amphiphilic block copolymers (ABC)-based self-assembled nanocarriers have attracted researchers worldwide owing to their unique properties. In this work, we addressed different biological barriers for effective cancer treatment along with several strategies to overcome them by using ABC‐based self-assembled nanostructures, with special emphasis in those that have the ability to act as responsive nanocarriers to internal or external environmental clues to trigger release of the payload. These nanocarriers have shown promising properties to revolutionize cancer treatment and diagnosis, but there are still challenges for their successful translation to clinical applications.

Magnetic hybrid nanomaterial based on a natural polymer and an amino acid as pH/temperature dual-responsive nanoplatform for the delivery of tamoxifen

“…Moreover, the HMNP-TMX may also be used to be remotely activated by an external magnetic field, triggering the drug release by magneticinduced heating response thanks to the presence of superparmagnetic Fe 3 O 4 nanoparticles. pH-sensitive nanocarriers can undergo conformational changes at acidic medium (Torres et al, 2020; and, in the case of hydrophilic polymers containing ionizable groups, pH changes affect their ionization state (Joseph, 2002), leading to the cargo release. This pH-sensitive behavior is of particular interest for the delivery of anticancer drugs because the extracellular pH of cancer tissues is slightly acidic due to the high metabolic activity of cancer cells.…”

“…Nanocarriers can achieve satisfactory tumor targeting by utilizing the enhanced permeability and retention (EPR) effect-mediated passive targeting strategy. Furthermore, active targeting can enhance the effectiveness of nanocarriers by conjugating them with ligands that can specifically target overexpressed receptors in tumor cells (García, 2020;Torres et al, 2020). The inclusion of active targeting ligands on the surface of nanoparticles improves their targeting toward tumor cells (on-targets) rather than healthy cells (off-targets).…”

Polymeric Nanostructures Containing Proteins and Peptides for Pharmaceutical Applications

“…Moreover, according to solvophilic and solvophobic segments of AmBCs, distinguishable morphologies such as micelles, lamellae, and vesicles can be observed. Remarkably, AmBCs micelles contribute to the delivery of solubilized water-insoluble molecules such as proteins, as reviewed in the following section [37,43]. Furthermore, the amenability of molecular features of the self-assembly process provides the ability of different polymers to be combined.…”

Pyridine-containing block copolymeric nano-assemblies obtained through complementary hydrogen-bonding directed polymerization-induced self-assembly in water

“…[1][2][3][4] Among the various BCPs, pyridine-containing ones have attracted particular attention due to the unique functionality of nitrogen within the aromatic pendants. [5][6][7][8][9] For example, the pyridine moieties inherently possess a pH-responsive feature owing to their protonation in acidic conditions and deprotona-tion in neutral or alkaline conditions (below or above the pK a ), [10][11][12] which can endow the material with an ideal platform for gene vector and targeted delivery. Moreover, the specific coordination ability of the pyridinyl nitrogen with various inorganic species can afford a wide landscape of applications including optical, electronic, magnetic, catalytic and conductive applications, and cargo-releasing polymeric nanomaterials.…”