scholarly journals Binary Graft of Poly(N-vinylcaprolactam) and Poly(acrylic acid) onto Chitosan Hydrogels Using Ionizing Radiation for the Retention and Controlled Release of Therapeutic Compounds

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2641
Author(s):  
Alejandra Ortega ◽  
Abigail Sánchez ◽  
Guillermina Burillo
Keyword(s):  
Ionizing Radiation ◽  
Acrylic Acid ◽  
Electrostatic Interactions ◽  
Ph Value ◽  
Direct Method ◽  
Direct Methods ◽  
Ph Sensitive ◽  
Solution Temperature ◽  
Chitosan Hydrogels ◽  
Critical Ph

In this study, we carried out the synthesis of a thermo- and pH-sensitive binary graft, based on N-vinylcaprolactam (NVCL) and pH sensitive acrylic acid (AAc) monomers, onto chitosan gels (net-CS) by ionizing radiation. Pre-oxidative irradiation and direct methods were examined, and materials obtained were characterized by FTIR-ATR, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and swelling tests (equilibrium swelling time, critical pH, and temperature). The best synthesis radiation method was the direct method, which resulted in the maximum grafting percentages (~40%) at low doses (10–12 kGy). The main goal of this study was the comparison of the swelling behavior and physicochemical properties of net-CS with those of the binary system (net-CS)-g-NVCL/AAc with the optimum grafting percentage (~30%). This produced a material that showed an upper critical solution temperature (UCST) of 33.5 °C and a critical pH value of 3.8, indicating the system is more hydrophilic at higher temperatures and low pH values. Load and release studies were carried out using diclofenac. The grafted system (32%) was able to load 19.3 mg g−1 of diclofenac and release about 95% within 200 min, in comparison to net-CS, which only released 80% during the same period. When the grafted system was protonated before diclofenac loading, it loaded 27.6 mg g−1. However, the drug was strongly retained in the material by electrostatic interactions and only released about 20%.

scholarly journals Interpolymer Complex Formation Between Linear and Crosslinked Poly(acrylic acid) and Poly(vinyl ether of ethyleneglycol)

2016 ◽  
Vol 2 (2) ◽  
pp. 125
Author(s):  
Z.S. Nurkeeva ◽  
G.A. Mun ◽  
V.V. Khutoryanskiy ◽  
V.A. Kan ◽  
E.M. Shaikhutdinov
Keyword(s):  
Ionic Strength ◽  
Acrylic Acid ◽  
Vinyl Ether ◽  
Ph Value ◽  
Interpolymer Complex ◽  
Interpolymer Complexes ◽  
Effects Of Ph ◽  
Linear Poly ◽  
Critical Ph ◽  
Poly Acrylic Acid

<p>The formation of H-bonded interpolymer complexes between linear and cross-linked poly(acrylic acid) and poly(vinyl ether of ethyleneglycol) is considered. The effects of pH and concentrations of polymers solution as well as the nature of the solvent on the complexation processes are discussed. It was found that the complexes are formed in aqueous solutions only below some critical pH value, which depends on the concentration of polymers and ionic strength of the solution. The interaction between gel of poly(acrylic acid) swollen in alcohol with solution of linear poly(vinyl ether of ethyleneglycol) is accompanied by formation of turbid layer of polycomplex and contraction of gel.</p>

scholarly journals Thermo-Responsive Behavior of Mixed Aqueous Solution of Hydrophilic Polymer with Pendant Phosphorylcholine Group and Poly(Acrylic Acid)

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 148
Author(s):  
Hirokazu Fukumoto ◽  
Kazuhiko Ishihara ◽  
Shin-Ichi Yusa
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Solution Temperature ◽  
Interpolymer Complex ◽  
Mixed Aqueous Solution ◽  
Upper Critical Solution Temperature ◽  
Acidic Conditions ◽  
Decreasing Ph ◽  
Increasing Temperature ◽  
Poly Acrylic Acid

A mixed aqueous solution of hydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(acrylic acid) (PAAc) becomes cloudy under acidic conditions at room temperature. The pendant carboxylic acid groups in PAAc form hydrogen bonds with the ester and phosphate groups in PMPC. While the polymers aggregate under acidic conditions, neither one associate under basic conditions because of the deprotonation of the pendant carboxy groups in PAAc. We observed that the interpolymer complex formed from PMPC, and PAAc was dissociated in aqueous solutions with increasing temperature, which is an upper critical solution temperature behavior. With increasing temperature, the molecular motion increased to dissociate the interpolymer complex. The phase transition temperature increased with increasing polymer and salt concentrations, and with decreasing pH.

Development of a facile one-pot synthesis method for an ingestible pH sensitive actuator

MRS Advances ◽  
2019 ◽  
Vol 5 (17) ◽  
pp. 881-889
Author(s):  
Alex Keller ◽  
Holly Warren ◽  
Marc in het Panhuis
Keyword(s):  
Acrylic Acid ◽  
Calcium Hydroxide ◽  
Sodium Citrate ◽  
Synthesis Method ◽  
Gastric Fluid ◽  
Ph Sensitive ◽  
One Pot ◽  
Acidic Environments ◽  
Printed Materials ◽  
Poly Acrylic Acid

ABSTRACTEdible devices are an emergent technology and in this paper the simplicity and efficacy that poly(acrylic acid)/calcium hydroxide possess in creating a pH sensitive ingestible actuator which responds to acidic environments such as gastric fluid is demonstrated. It was found that poly(acrylic acid)/calcium hydroxide hydrogels exhibit reversible actuation upon submerging in 0.1 M sodium citrate for 2 hours. Our results show that these hydrogels can restore their compressive stress to 0.19 ± 0.06 MPa, swelling ratio to 26 ± 2 and volume to 56% ± 3% of its original volume. This work offers new possibilities for developments in a variety of fields such as drug delivery, 4D printed materials, soft robotics and edible devices.

Preparation and characterization of a novel pH-sensitive Salecan-g-poly(acrylic acid) hydrogel for controlled release of doxorubicin

2015 ◽  
Vol 3 (13) ◽  
pp. 2685-2697 ◽  
Author(s):  
Xinyu Hu ◽  
Wei Wei ◽  
Xiaoliang Qi ◽  
Hao Yu ◽  
Liandong Feng ◽  
...  
Keyword(s):  
Controlled Release ◽  
Acrylic Acid ◽  
Ph Sensitive ◽  
Swelling Behaviour ◽  
Poly Acrylic Acid

The pH-sensitive swelling behaviour and DOX release of Salecan-g-PAA hydrogels are discussed.

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