Strategies To Design and Synthesize Polymer‐Based Stimuli‐Responsive Drug‐Delivery Nanosystems

Abstract

The emergence and development of nanomedicine have alleviated problems existing in traditional chemotherapy drugs, such as short lifetime, concomitant side effects, and weak tumor‐targeting capability. Nevertheless, the further applications of drug‐loaded nanocarriers are still limited by their premature leakage, weak targeting capability, and insufficient intracellular release. In past decades, various nanocarriers, including gold nanoparticles, porous silica nanoparticles, carbon‐based nanoparticles, micelles, liposomes, and polymer–drug conjugates, have been intensively investigated for tumor therapy. Among these, polymer‐based nanocarriers have attracted more attention due to their biocompatibilities and capability of being modified for stimuli‐responsive drug release. In this review, three popular strategies to design and synthesize polymer‐based stimuli‐responsive nanocarriers are discussed. The discussion goes from stimuli‐responsive polymers with responsive backbones or modified by responsive functional groups for drug encapsulation and release to polymer–drug conjugates with responsive covalent linkages. In particular, due to the facile synthetic processes and mild reaction conditions for crosslinked structures, the latest progress in responsive crosslinked structures is emphasized. Finally, future perspectives for these nanomaterials are given, which are expected to provide inspiration for researchers to design more effective and safer tumor‐killing nanomedicines.

Recent Advances in Polymeric Nanoparticle-Encapsulated Drugs against Intracellular Infections

“…It used PNs functionalized with the Fc fragment of IgG to target neonatal Fc receptor (FcRn) through an FcRn-mediated transcytosis mechanism so the PNs can finally overstep the intestinal epithelium. Valuable information that may be of interest to the reader have also been reviewed elsewhere regarding nanotherapeutics of leishmaniasis [ 120 , 236 , 237 ], tuberculosis [ 238 , 239 , 240 , 241 , 242 ], viral infections [ 243 , 244 ], HIV [ 245 , 246 , 247 , 248 , 249 ], malaria [ 118 , 250 , 251 , 252 ], infectious diseases [ 4 , 45 , 66 , 253 ], intracellular delivery [ 59 , 60 , 64 , 83 , 254 , 255 ], bacterial pathogens [ 46 , 192 , 256 , 257 , 258 , 259 ] and stimuli-responsive systems [ 15 , 58 , 260 , 261 , 262 ].…”

Stimulus-responsive liposomes for biomedical applications

“…Nanotechnology can indeed address several among the major issues that hamper therapeutic efficacy, limiting bench-to-clinic translation of new developed bioactive compounds [1,2]. In this context, the development of nanosystems for drug delivery is particularly burgeoning [3,4]. Appropriate nanovehicles can significantly enhance drug efficacy through an increased delivery to the molecular target and reduction of off-target effects.…”

Polymeric Nanocarriers: A Transformation in Doxorubicin Therapies

“…Additionally, to achieve active targeting, a large number of ligands have been employed, including polysaccharides and peptides (i.e., hyaluronic acid and RGD peptide), as well as small molecules like folate or anisamidephenylbornic acid [ 78 , 79 ]. Furthermore, overexpression of enzymes, i.e., proteases, is another approach that can be used to design responsive DDSs [ 80 , 81 ]. In the enzyme–sensitive DDSs, the peptide side chain is designed as a specific substrate of a target enzyme that could directly release the drug from a carrier.…”