Polymers, responsiveness and cancer therapy

Abstract

A single outcome in a biological procedure at the time of cancer therapy is due to multiple changes happening simultaneously. Hence to mimic such complex biological processes, an understanding of stimuli responsiveness is needed to sense specific changes and respond in a predictable manner. Such responses due to polymers may take place either simultaneously at the site or in a sequential manner from preparation to transporting pathways to cellular compartments. The present review comprehends the stimuli-responsive polymers and multi-responsiveness with respect to cancer therapy. It focuses on the exploitation of different stimuli like temperature, pH and enzymes responsiveness in a multi-stimuli setting. Nanogels and micelles being two of the most commonly used responsive polymeric carriers have also been discussed. The role of multiple stimuli delivery system is significant due to multiple changes happening in the near surroundings of cancer cells. These responsive materials are able to mimic some biological processes and recognize at the molecular level itself to manipulate development of custom-designed molecules for targeting cancer cells.

Polymers and Polymer Nanocomposites for Cancer Therapy

“…The shift from mono-to dual-and then to multistimuli-responsive polymers, including hydro-and nanogels, has increased confidence in their ability to deliver drugs intracellularly while overcoming the problems associated with mono-and dual-responsive products. The sensitivity of these macromolecules to multiple stimuli makes them quite versatile and increases their applicability [108].…”

The rise of bio-inspired polymer compartments responding to pathology-related signals

“…Predominant environmental changes that can trigger a specific response from a polymer assembly include the variation of pH or ionic strength, the presence of reactive oxygen species, redox agents and other bio-or chemical molecules. [9][10][11][12][13][14][15] Externally applied stimuli, such as light, temperature, ultrasound and electrical or magnetic fields can also trigger a response in polymer-based assemblies, 12,17-20 but we did not include them in this overview.…”

“…2,10,28,36,[45][46][47][48] Moreover, the efficacy of polymer compartments can be increased by localizing them via targeting moieties to specific sites in the body. 15,29,45,49 Specifically, we present how polymer biosensors can be tailored to change their properties in response to the presence of stimuli in a bioinspired manner based on the behavior of natural organelles inside cells or cells that respond to specific intracellular or intercellular signals while preserving their integrity. Stimuli-responsiveness is a key property both for drug delivery systems where physical or chemical changes of the polymer induce the release 'on demand' of the encapsulated cargo, and for sensors that detect changes associated with pathological conditions.…”

An outlook on procedures of conjugating folate to (co)polymers and drugs for effective cancer targeting

“…They are beneficial in reducing some of the critical issues associated with the conventional drugs like bypassing the biological barriers, and overcoming the drug resistance to a greater extent. Targeted therapies minimize the toxic effects on to the healthy cells and specifically kill the cancer cells (Bertrand, Wu, Xu, Kamaly, & Farokhzad, 2014; Leamon & Low, 2001; Pethe & Yadav, 2019; Soni & Yadav, 2017; Sudimack & Lee, 2000; Yadav, Saxena, & Soni, 2017). For the active targeting, there has to be appropriate receptor inside the body.…”