Thermo- and pH-responsive copolymers based on PLGA-PEG-PLGA and poly(l-histidine): Synthesis and in vitro characterization of copolymer micelles

Surface sulfonamide modification of poly(N‐isopropylacrylamide)‐based block copolymer micelles to alter pH and temperature responsive properties for controlled intracellular uptake

“…When they self‐assemble into polymeric micelles with core‐corona nanostructures, micelles are particularly attractive drug delivery platforms which respond to specific stimuli to deliver and release drugs at target disease sites, such as mildly acidic tumor extracellular environment. Some of these micelles rely on stimuli such as temperature (heating/cooling) and pH to elicit structural and functional changes of constituent intelligent polymers . Poly( N ‐isopropylacrylamide) [poly(IPAAm)] is widely used since it demonstrates thermoresponsive phase transition behavior at its lower critical solution temperature (LCST) of 32°C near physiological temperature in water .…”

“…Additionally, when hyperthermia is used, it can improve the cellular uptake of thermoresponsive vehicles since it increases the permeability of tissue . Using local heating, thermoresponsive polymer‐based vehicles have the potential to be used to deliver and release drugs targeted for intracellular or gene delivery …”

pH-Sensitive Poly(itaconic acid)-poly(ethylene glycol)-poly(L-histidine) Micelles for Drug Delivery

“…However, the EPR effect can only enhance the accumulation of micelles in tumor tissues, the poor cellular internalization or membrane permeability as well as insufficient intracellular drug release always hampers the efficacy of cancer chemotherapy (13)(14)(15). To address the challenges, environment-responsive delivery systems (16)(17)(18)(19)(20) including pH (21), temperature (22), light (10), enzymatic reactions (23), have been attempted to improve the drug bioavailability, because they can be designed to undergo a tumor specific material transition that can lead to their programmed disassembly within a tumor, thereby releasing their lower molecular weight constituents which can more readily diffuse within the tumor. The pH gap between tumor tissues and normal tissues is frequently utilized as the stimulus for pH-responsive delivery of therapeutic drugs and imaging agents (24)(25)(26)(27).…”

Synthesis and characterization of pH-sensitive poly(itaconic acid)–poly(ethylene glycol)–folate–poly(l-histidine) micelles for enhancing tumor therapy and tunable drug release

“…These stimulus responsive polymers are capable of responding to external stimulus，such as changes in temperature [19], pH [20,21], light [22], enzymatic reactions [23], or redox [24],with a sharp change in their properties. Of the many stimuli that can be investigated, pH-responsive system is most frequently used because obvious pH changes occur within the various tissues and cellular compartments along the endocytic pathway [25][26][27][28].…”