Abstract:Temperature can be harnessed to engineer unique properties for materials useful in various contexts and has been shown to affect the layer-by-layer (LbL) assembly of polymer thin films and cause physical changes in preassembled polymer thin films. Herein we demonstrate that exposure to relatively low temperatures (≤ 100 °C) can induce physicochemical changes in cationic polymer thin films. The surface charge of polymer films containing primary and secondary amines reverses after heating (from positive to negat… Show more
“…2b). Zeta-potential measurements showed the micelles bear a slightly negative surface charge of −6.98 mV (Additional file 1: Figure S3), which could allow its circulation in blood without overly captured by macrophageal and reticuloendothelial system [42, 43]. Overall, the nanoscale system prepared by PPS-PNIPAm polymer possesses suitable size and surface charge allowing its circulation in blood and accumulation in tumoral site through EPR effect.Fig.…”
BackgroundThe object of this study was to develop a thermally and reactive oxygen species-responsive nanocarrier system for cancer therapy.ResultsPPS-PNIPAm block copolymer was designed and synthesised using a combination of living anionic ring-opening polymerization and atom transfer radical polymerization. The synthesized polymer formed micellar aggregates in water and demonstrated dual responsiveness towards temperature and oxidants. Using doxorubicin (DOX) as a model drug, encapsulation and in vitro release of the drug molecules in PPS-PNIPAm nanocarriers confirmed the responsive release properties of such system. Cell uptake of the DOX loaded micelles was investigated with human breast cancer cell line (MCF-7). The results showed Dox-loaded micelles were able to be taken by the cells and mainly reside in the cytoplasma. In the stimulated cells with an elevated level of ROS, more released DOX was observed around the nuclei. In the cytotoxicity experiments, the Dox-loaded micelles demonstrated comparable efficacy to free DOX at higher concentrations, especially on ROS stimulated cells.ConclusionsThese results demonstrated that PPS-PNIPAm nanocarriers possess the capability to respond two typical stimuli in inflammatory cells: temperature and oxidants and can be used in anticancer drug delivery.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-017-0275-4) contains supplementary material, which is available to authorized users.
“…2b). Zeta-potential measurements showed the micelles bear a slightly negative surface charge of −6.98 mV (Additional file 1: Figure S3), which could allow its circulation in blood without overly captured by macrophageal and reticuloendothelial system [42, 43]. Overall, the nanoscale system prepared by PPS-PNIPAm polymer possesses suitable size and surface charge allowing its circulation in blood and accumulation in tumoral site through EPR effect.Fig.…”
BackgroundThe object of this study was to develop a thermally and reactive oxygen species-responsive nanocarrier system for cancer therapy.ResultsPPS-PNIPAm block copolymer was designed and synthesised using a combination of living anionic ring-opening polymerization and atom transfer radical polymerization. The synthesized polymer formed micellar aggregates in water and demonstrated dual responsiveness towards temperature and oxidants. Using doxorubicin (DOX) as a model drug, encapsulation and in vitro release of the drug molecules in PPS-PNIPAm nanocarriers confirmed the responsive release properties of such system. Cell uptake of the DOX loaded micelles was investigated with human breast cancer cell line (MCF-7). The results showed Dox-loaded micelles were able to be taken by the cells and mainly reside in the cytoplasma. In the stimulated cells with an elevated level of ROS, more released DOX was observed around the nuclei. In the cytotoxicity experiments, the Dox-loaded micelles demonstrated comparable efficacy to free DOX at higher concentrations, especially on ROS stimulated cells.ConclusionsThese results demonstrated that PPS-PNIPAm nanocarriers possess the capability to respond two typical stimuli in inflammatory cells: temperature and oxidants and can be used in anticancer drug delivery.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-017-0275-4) contains supplementary material, which is available to authorized users.
“…Thermo-responsive charge-reversal carriers retain their load at body temperature and reverse their surface charge following thermos-response triggering. Caruso et al 25 synthesized a poly(allylamine) hydrochloride (PAH) coated SiO 2 nanoparticle. The act of heating could cause the cationic polymer PAH to lose its inherent positive charge and become negative without any polymer desorption.…”
Spurred by significant progress in materials chemistry and drug delivery, charge-reversal nanocarriers are being developed to deliver anticancer formulations in spatial-, temporal- and dosage-controlled approaches. Charge-reversal nanoparticles can release their drug payload in response to specific stimuli that alter the charge on their surface. They can elude clearance from the circulation and be activated by protonation, enzymatic cleavage, or a molecular conformational change. In this review, we discuss the physiological basis for, and recent advances in the design of charge-reversal nanoparticles that are able to control drug biodistribution in response to specific stimuli, endogenous factors (changes in pH, redox gradients, or enzyme concentration) or exogenous factors (light or thermos-stimulation).
“…The size and the wall thickness of hollow capsules synthesized by this technique can be influenced by the size of the sacrificial silica template and the molecular weight of the used polymers . A similar strategy of using single polymeric component to fabricate hollow capsules was also presented in various papers …”
Section: Common Methods For Preperation Of Polymeric Hollow Capsulesmentioning
Polymeric hollow capsules have attracted increasing interest for the development of controlled drug delivery systems due to their capacities to load high amount of drugs and be able to finely tune the drug release profile. Various methods and strategies for capsule preparation and drug loading have been developed over time. Besides that, the controlled drug release from hollow capsules upon external and internal triggers is of great interest and has been a research focus in this area. This article aims to give the most recent progress review on hollow capsule based controlled drug delivery systems with a highlight on strategies being used for drug loading and stimuli-release. In detail, the fabrication of hollow capsules using templateassisted or template-free methods will be introduced first. This will be followed by current strategies for pre-loading and postloading of therapeutic agents into capsules. The article will then be particularly focused on discussing diverse drug-release systems corresponding to various stimuli conditions including temperature, pH, ultrasound, light irradiation and enzyme degradation.
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