سیستم های پاسخگو به محرک برای درمان هدفمند سرطان
Abstract
1- Introduction
2- pH-responsive polymeric nanocarriers
3- Temperature-responsive polymeric nanocarriers
4- Redox potential-responsive polymeric nanocarriers
5- Enzyme-responsive polymeric nanocarriers
6- Light-responsive polymeric nanocarriers
7- Dual-responsive polymeric nanocarriers
8- Future perspectives
9- Conclusions
References
Abstract
In the last decade, considerable attention has been devoted to the use of biodegradable polymeric materials as potential drug delivery carriers. However, bioavailability and drug release at the disease site remain uncontrollable even with the use of polymeric nanocarriers. To address this issue, successful methodologies have been developed to synthesize polymeric nanocarriers incorporated with regions exhibiting a response to stimuli such as redox potential, temperature, pH, and light. The resultant stimuli-responsive polymeric nanocarriers have shown tremendous promise in drug delivery applications, owing to their ability to enhance the bioavailability of drugs at the disease site. In such systems, drug release is controlled in response to specific stimuli, either exogenous or endogenous. This review reports recent advances in the design of stimuli-responsive nanocarriers for drug delivery in cancer therapy. In particular, the synthetic methodologies investigated to date to introduce different types of stimuli-responsive elements within the biomaterials are described. The sufficient understanding of these stimuli-responsive nanocarriers will allow the development of a better drug delivery system that will allow us to solve the challenges encountered in targeted cancer therapy.
Conclusions
In this review, it was focused on the most recent advances in the development of stimuli-responsive nanocarriers for drug delivery in cancer therapy. These smart drug delivery systems respond to the distinct changes in cancer cells, such as changes in pH gradient and elevated secretion of certain enzymes, rather than the conditions in normal cells. Targeting tumors with stimuliresponsive nanocarriers could not only increase the therapeutic benefit and minimize associated toxicity, but could also enhance the curative effect by specifically releasing the anti-cancer drug in a powerful precise mode, both temporally and spatially. The different approaches adopted to incorporate stimuli responsive elements within the polymeric nanocarriers were discussed, with a particular focus on polymeric materials with stimuliresponsive mechanisms in response to pH, redox potential, enzymes, temperature, and light. Despite the tremendous progress that has been made regarding the engineering of new stimuli-responsive materials, several challenges still remain to be addressed with respect to nanomedicine applications. For example, their biodegradability and biocompatibility profiles should be critically investigated prior to utilization in human clinical trials. Many of these systems have only been reported as an in vitro proof-of-concept and follow-up work in vivo preclinical models has been described for only a few. However, the translation of these stimuli-responsive delivery systems from the bench to the bedside might be facilitated, to some extent, if the regulatory requirements for human clinical trials are considered in light of the key features that render a biopolymer suitable for biomedical application, such as biocompatibility, biodegradability, high drug loading capability, programmable release, excellent in vivo stability, non-cytotoxicity, and ability to support effective targeting. Given the ongoing developments in the field of bionanotechnology along with the wide knowledge accumulated over recent years, it is convinced that the collaborative efforts of chemists, biologists, and medicinal and pharmaceutical scientists will revolutionize the design of responsive polymeric materials for cancer therapy to significantly improve both the quality and duration of the lives of patients with cancer.