Ethidium bromide-bridged mesoporous silica hybrid nanocarriers for fluorescence cell imaging and drug delivery applications

et al. 2022

Polymers

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The therapeutic delivery system with dual stimuli-responsiveness has attracted attention for drug delivery to target sites. In this study, we used free radical polymerization to develop a temperature and pH-responsive poly(N-isopropyl acrylamide)-co-poly(acrylamide) (PNIPAM-co-PAAm). PNIPAm-co-PAAm copolymer by reacting with N-isopropyl acrylamide (NIPAm) and acrylamide (Am) monomers. In addition, the synthesized melamine-glutaraldehyde (Mela-Glu) precursor was used as a cross-linker in the production of the melamine cross-linked PNIPAm-co-PAAm copolymer hydrogel (PNIPAm-co-PAAm-Mela HG) system. The temperature-responsive phase transition characteristics of the resulting PNIPAM-co-PAAm-Mela HG systems were determined. Furthermore, the pH-responsive drug release efficiency of curcumin was investigated under various pH and temperature circumstances. Under the combined pH and temperature stimuli (pH 5.0/45 °C), the PNIPAm-co-PAAm-Mela HG demonstrated substantial drug loading (74%), and nearly complete release of the loaded drug was accomplished in 8 h. Furthermore, the cytocompatibility of the PNIPAm-co-PAAm-Mela HG was evaluated on a human liver cancer cell line (HepG2), and the findings demonstrated that the prepared PNIPAm-co-PAAm-Mela HG is biocompatible. As a result, the PNIPAm-co-PAAm-Mela HG system might be used for both pH and temperature-stimuli-responsive drug delivery.

Section: Resultsmentioning

confidence: 99%

pH and Thermoresponsive PNIPAm-co-Polyacrylamide Hydrogel for Dual Stimuli-Responsive Controlled Drug Delivery

Thirupathi¹,

Phan

et al. 2022

Polymers

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“…In comparison, approximately ~63% and >90% of the Cur release occurred within 5 h at pH 6.5 and pH 4.0, respectively. The increased Cur release at acidic pH (pH 4.0) than at physiological pH (pH 7.2) could be due to the protonation of drug binding sites such as amine (-NH 2 ) and amide (CO-NH-) groups of Am and NIPAm groups, which causes electrostatic repulsion between the protonated drug binding functional groups and the Cur molecules [32]. Secondly, the Cur release behavior of the p(NIPAm-co-Am) NG/Cur system was examined under several temperature-stimuli settings, such as 25 • C, 37 • C, and 42 • C, while keeping the solution pH at around pH 7.2.…”

Section: Stimuli-responsive Drug Delivery Behavior Of the P(nipam-co-...mentioning

confidence: 99%

Dual pH- and Thermo-Sensitive Poly(N-isopropylacrylamide-co-allylamine) Nanogels for Curcumin Delivery: Swelling–Deswelling Behavior and Phase Transition Mechanism

Kim

2023

Gels

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Curcumin (Cur) is a beneficial ingredient with numerous bioactivities. However, due to its low solubility and poor bioavailability, its therapeutic application is limited. In this work, we prepared poly-N-isopropylacrylamide p(NIPAm) and polyallylamine p(Am)-based nanogel (p(NIPAm-co-Am)) NG for a dual pH- and temperature-sensitive copolymer system for drug delivery application. In this copolymer system, the p(NIPAm) segment was incorporated to introduce thermoresponsive behavior and the p(Am) segment was incorporated to introduce drug binding sites (amine groups) in the resulting (p(NIPAm-co-Am)) NG system. Various instrumental characterizations including 1H nuclear magnetic resonance (1H NMR) spectroscopy, Fourier transform infrared (FT-IR) analysis, scanning electron microscopy (SEM), zeta potential, and particle size analysis were performed to confirm the copolymer synthesis. Curcumin (Cur), an anticancer bioactive substance, was employed to assess the in vitro drug loading and release performance of the resulting copolymer nanogels system at varied pH levels (pH 7.2, 6.5, and 4.0) and temperatures (25 °C, 37 °C, and 42 °C). The cytocompatibility of the p(NIPAm-co-Am) NG sample was also tested on MDA-MB-231 cells at various sample concentrations. All the study results indicate that the p(NIPAm-co-Am) NG produced might be effective for drug loading and release under pH and temperature dual-stimuli conditions. As a result, the p(NIPAm-co-Am) NG system has the potential to be beneficial in the use of drug delivery applications in cancer therapy.

“…The intracellular uptake behavior of the MDA-MB-231 cells was also examined at different time (1, 2, 4, and 8 h) intervals. According to Figure 8 d, increased fluorescence intensity of Dox in the cells with respect to time indicates effective cellular internalization of MS@Dox/PNIPAm-PAAm NPs inside the cells via the intracellular internalization process [ 43 , 44 , 45 ]. The fluorescence image results provide direct evidence for the pH-responsive delivery performance of Dox from the MS@Dox/PNIPAm-PAAm NPs.…”

Section: Resultsmentioning

confidence: 99%

Thermosensitive Polymer-Modified Mesoporous Silica for pH and Temperature-Responsive Drug Delivery

Thirupathi¹,

Radhakrishnan

et al. 2023

Pharmaceutics

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A mesoporous silica-based drug delivery system (MS@PNIPAm-PAAm NPs) was synthesized by conjugating the PNIPAm-PAAm copolymer onto the mesoporous silica (MS) surface as a gatekeeper that responds to temperature and pH changes. The drug delivery studies are carried out in vitro at different pH (7.4, 6.5, and 5.0) and temperatures (such as 25 °C and 42 °C, respectively). The surface conjugated copolymer (PNIPAm-PAAm) acts as a gatekeeper below the lower critical solution temperature (LCST) (<32 °C) and as a collapsed globule structure above LCST (>32 °C), resulting in controlled drug delivery from the MS@PNIPAm-PAAm system. Furthermore, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cellular internalization results support the prepared MS@PNIPAm-PAAm NPs being biocompatible and readily taken up by MDA-MB-231 cells. The prepared MS@PNIPAm-PAAm NPs, with their pH-responsive drug release behavior and good biocompatibility, could be used as a drug delivery vehicle where sustained drug release at higher temperatures is required.