Polymer-Drug Conjugates as Nanotheranostic Agents

Abstract

Since the last decade, the polymer-drug conjugate (PDC) approach has emerged as one of the most promising drug-delivery technologies owing to several benefits like circumventing premature drug release, offering controlled and targeted drug delivery, improving the stability, safety, and kinetics of conjugated drugs, and so forth. In recent years, PDC technology has advanced with the objective to further enhance the treatment outcomes by integrating nanotechnology and multifunctional characteristics into these systems. One such development is the ability of PDCs to act as theranostic agents, permitting simultaneous diagnosis and treatment options. Theranostic nanocarriers offer the opportunity to track the distribution of PDCs within the body and help to localize the diseased site. This characteristic is of particular interest, especially among those therapeutic approaches where external stimuli are supposed to be applied for abrupt drug release at the target site for localized delivery to avoid systemic side effects (e.g., Visudyne®). Thus, with the help of this review article, we are presenting the most recent updates in the domain of PDCs as nanotheranostic agents. Different methodologies utilized to design PDCs along with imaging characteristics and their applicability in a wide range of diseases, have been summarized in this article.

Recent Progress in Nanostructured Smart Drug Delivery Systems for Cancer Therapy: A Review

“…The cross-linkers can be cleaved by stimuli such as pH, environment, enzyme, light, temperature, magnetic effect, and ultrasound. 198,199 Polymer−drug conjugates have been evaluated for various cancer treatment research such as breast cancer, 200 lung cancer, 119,200 and colon cancer. 201 The size of polymer−drug conjugates can also affect the cytotoxicity against the cancer cell.…”

“…In addition to the targeting moieties, linkers such as peptide, disulfides, and azo bonds are used as cross-linkers between the polymers and the drugs. The cross-linkers can be cleaved by stimuli such as pH, environment, enzyme, light, temperature, magnetic effect, and ultrasound. , Polymer–drug conjugates have been evaluated for various cancer treatment research such as breast cancer, lung cancer, , and colon cancer . The size of polymer–drug conjugates can also affect the cytotoxicity against the cancer cell.…”

Nanotheranostics-An Emerging Technique in Nanomedicine

“…Another method that can be used to identify and target cancer cells is the detection of glutathione which is overly expressed in cancer cells and can be used for development of nanotheranostics [67]. Besides, another reported method is the generation of hydrophobic drugs conjugated with hydrophilic polymers [68]. The monomers that are produced are amphiphilic and cause nanoparticles to assemble themselves.…”

PEGylated Magnetite/Hydroxyapatite: A Green Nanocomposite for T2-Weighted MRI and Curcumin Carrying

“…Coating nanostructures with PEG plays a crucial role in improving their chemical and biophysical properties [ 17 ]. In the PEGylation process, PEG is conjugated to a therapeutic drug, leading to the improved water solubility of hydrophobic chemotherapeutic drugs, increased blood half-life of the nanostructures, and provided the ability of specific tumor targeting [ 24 ].…”