Double stimuli-responsive polysaccharide block copolymers as green macrosurfactants for near-infrared photodynamic therapy

Soft Matter ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1423-1434 ◽  
Author(s):  
Benjamin B. Breitenbach ◽  
Elena Steiert ◽  
Matthias Konhäuser ◽  
Lea-Marie Vogt ◽  
Yujen Wang ◽  
...  

The NIR absorbing photosensitizer phthalocyanine zinc (PC(Zn)) was stabilized in aqueous media as water-dispersible nanoparticles with a reduction- and pH-responsive full polysaccharide block copolymer.

2017 ◽  
Vol 259 ◽  
pp. e74-e75
Author(s):  
Le Liu ◽  
Liyi Fu ◽  
Titao Jing ◽  
Zheng Ruan ◽  
Lifeng Yan

2012 ◽  
Vol 27 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Young Ju Son ◽  
Hyuk Sang Yoo

Block copolymer-stabilized iron oxide nanoaggregates were fabricated into pH-responsive polymeric microspheres for intestinal delivery of the magnetic nanoaggregates. A diblock copolymer consisted of methoxy poly(ethylene glycol) (mPEG) and poly(e-caprolactone) (PCL) was synthesized by ring-opening polymerization. Microspheres, consisted of Eudragit L100-55 encapsulate and stabilized magnetic nanoaggregates, were prepared by an oil-in-oil emulsification technique. The magnetization of the microspheres decreased, and the stability of the magnetic nanoaggregates in aqueous solutions increased as the amount of block copolymers in the microspheres increased. The encapsulated magnetic nanoaggregates were visualized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The encapsulation efficiency of nanoaggregates of the microspheres increased as the amount of diblock copolymer in the nanoaggregates was increased. The in vitro experiments confirmed the pH-dependent release of the nanoaggregates from the microspheres. The microspheres were administered to the animals by oral gavages, and the nanoaggregates in small intestines were visualized by histological examination of intestinal inner walls. Higher amounts of the block copolymer in the nanoaggregates increased the uptake efficiency in the intestinal tissues. Thus, the incorporation of the block copolymers in the magnetic nanoaggregates increased the intestinal absorption of the aggregates and Eudragit microspheres and effectively protected the nanoaggregates at low pH conditions of the stomach area.


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1400 ◽  
Author(s):  
Maria Chountoulesi ◽  
Natassa Pippa ◽  
Varvara Chrysostomou ◽  
Stergios Pispas ◽  
Evangelia D. Chrysina ◽  
...  

There is an emerging need to evolve the conventional lyotropic liquid crystalline nanoparticles to advanced stimuli-responsive, therapeutic nanosystems with upgraded functionality. Towards this effort, typically used stabilizers, such as Pluronics®, can be combined or replaced by smart, stimuli-responsive block copolymers. The aim of this study is to incorporate the stimuli-responsive amphiphilic block copolymer poly(2-(dimethylamino)ethyl methacrylate)-b-poly(lauryl methacrylate) (PDMAEMA-b-PLMA) as a stabilizer in lipidic liquid crystalline nanoparticles, in order to provide steric stabilization and simultaneous stimuli-responsiveness. The physicochemical and morphological characteristics of the prepared nanosystems were investigated by light scattering techniques, cryogenic-transmission electron microscopy (cryo-TEM), X-ray diffraction (XRD) and fluorescence spectroscopy. The PDMAEMA-b-PLMA, either individually or combined with Poloxamer 407, exhibited different modes of stabilization depending on the lipid used. Due to the protonation ability of PDMAEMA blocks in acidic pH, the nanoparticles exhibited high positive charge, as well as pH-responsive charge conversion, which can be exploited towards pharmaceutical applications. The ionic strength, temperature and serum proteins influenced the physicochemical behavior of the nanoparticles, while the polymer concentration differentiated their morphology; their micropolarity and microfluidity were also evaluated. The proposed liquid crystalline nanosystems can be considered as novel and attractive pH-responsive drug and gene delivery nanocarriers due to their polycationic content.


Nanoscale ◽  
2021 ◽  
Author(s):  
Katharina Leer ◽  
Gizem Cinar ◽  
Jana I. Solomun ◽  
Liam Martin ◽  
Ivo Nischang ◽  
...  

Stimuli-responsive block copolymer micelles can provide tailored properties for the efficient delivery of genetic material.


2021 ◽  
Author(s):  
Shuqi Dong ◽  
Li Liu ◽  
Hanying Zhao

In this work, we synthesized oxidation-responsive amphiphilic block copolymers PEG45-b-P(MET/PBC)n bearing pendant phenylboronic ester carbamate (PBC) and thioether moieties in the hydrophobic block by RAFT polymerization and post-polymerization modification. As...


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 956 ◽  
Author(s):  
Sotaro Tsuji ◽  
Tomohiro Aoki ◽  
Shunsuke Ushio ◽  
Tomonari Tanaka

Stimuli-responsive polymers have attracted significant interest in the fields of advanced materials and biomaterials. Herein, temperature- and pH-responsive glycopolymers, which are composed of N-isopropylacrylamide, methacrylic acid, and an acrylamide derivative bearing a lactose moiety, were synthesized via radical copolymerization. The series of resulting glycopolymers had different degrees of substitution of the lactose moieties, were responsive to temperatures between 26.6 °C and 47.6 °C, and formed aggregates above the lower critical solution temperature limit in mild acidic aqueous media (pH 4–6). The temperature-responsive behavior was dependent on the prevailing pH conditions, as no aggregation was observed in neutral and basic aqueous media (pH > 7). The aggregates had saccharide moieties on the surface in aqueous media. The number of saccharide moieties on the surface depended on the saccharide-containing unit ratio in the glycopolymer. The ratio was determined via enzymatic hydrolysis of the lactose moieties using β-galactosidase and the subsequent detection of the released galactose.


2019 ◽  
Vol 7 (43) ◽  
pp. 6770-6777 ◽  
Author(s):  
Pan Yuan ◽  
Zheng Ruan ◽  
Tuanwei Li ◽  
Youliang Tian ◽  
Quan Cheng ◽  
...  

Mannose conjugated polypeptide nanoparticles as a pH-responsive prodrug for enhanced near infrared imaging-guided photodynamic therapy.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 818
Author(s):  
Natalia Lange ◽  
Wojciech Szlasa ◽  
Jolanta Saczko ◽  
Agnieszka Chwiłkowska

Photodynamic therapy (PDT) is a method of cancer treatment that leads to the disintegration of cancer cells and has developed significantly in recent years. The clinically used photosensitizers are primarily porphyrin, which absorbs light in the red spectrum and their absorbance maxima are relatively short. This review presents group of compounds and their derivatives that are considered to be potential photosensitizers in PDT. Cyanine dyes are compounds that typically absorb light in the visible to near-infrared-I (NIR-I) spectrum range (750–900 nm). This meta-analysis comprises the current studies on cyanine dye derivatives, such as indocyanine green (so far used solely as a diagnostic agent), heptamethine and pentamethine dyes, squaraine dyes, merocyanines and phthalocyanines. The wide array of the cyanine derivatives arises from their structural modifications (e.g., halogenation, incorporation of metal atoms or organic structures, or synthesis of lactosomes, emulsions or conjugation). All the following modifications aim to increase solubility in aqueous media, enhance phototoxicity, and decrease photobleaching. In addition, the changes introduce new features like pH-sensitivity. The cyanine dyes involved in photodynamic reactions could be incorporated into sets of PDT agents.


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