scholarly journals pH-Responsive Micelles Assembled by Three-Armed Degradable Block Copolymers with a Cholic Acid Core for Drug Controlled-Release

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 511 ◽  
Author(s):  
Jingjie Feng ◽  
Weiqiu Wen ◽  
Yong-Guang Jia ◽  
Sa Liu ◽  
and Jianwei Guo
Keyword(s):  
Controlled Release ◽  
Block Copolymers ◽  
Cholic Acid ◽  
Drug Loading ◽  
Ph Responsive ◽  
Triggered Release ◽  
Drug Controlled Release ◽  
Release Studies ◽  
Good Biocompatibility ◽  
Poly Ethylene

One of the most famous anticancer drugs, paclitaxel (PTX), has often been used in drug controlled-release studies. The polymers derived from bio-compound bile acids and degradable poly(ε-caprolactone) (PCL) form a reservoir and have been used as a drug delivery system with great advantages. Herein, we grafted poly(N,N-diethylaminoethyl methacrylate) and poly(poly(ethylene glycol) methyl ether methacrylate) into the bile acid-derived three-armed macroinitiator CA-(PCL)3, resulting in the amphiphilic block copolymers CA-(PCL-b-PDEAEMA-b-PPEGMA)3. These pH-responsive three-armed block copolymers self-assembled into micelles in aqueous solution and PTX was encapsulated into the micellar core to form PTX-loaded micelles with a drug loading of 29.92 wt %. The micelles were stable in PBS at pH 7.4 and showed a pH-triggered release behavior of PTX under acidic environments, in which 55% of PTX was released at pH 5.0 in 80 h. These cholic acid-based functionalized three-armed block polymers present good biocompatibility, showing great potential for drug controlled-release.

scholarly journals A New Approach to Developing Long-Acting Injectable Formulations of Anti-HIV Drugs: Poly(Ethylene Phosphoric Acid) Block Copolymers Increase the Efficiency of Tenofovir against HIV-1 in MT-4 Cells

2020 ◽  
Vol 22 (1) ◽  
pp. 340
Author(s):  
Ilya Nifant’ev ◽  
Andrei Siniavin ◽  
Eduard Karamov ◽  
Maxim Kosarev ◽  
Sergey Kovalchuk ◽  
...  
Keyword(s):  
Controlled Release ◽  
Block Copolymers ◽  
Phosphoric Acid ◽  
Hiv Infection ◽  
Targeted Delivery ◽  
Release Formulation ◽  
Poly Ethylene ◽  
Long Acting ◽  
Hiv Drugs ◽  
Anti Hiv

Despite the world’s combined efforts, human immunodeficiency virus (HIV), the causative agent of AIDS, remains one of the world’s most serious public health challenges. High genetic variability of HIV complicates the development of anti-HIV vaccine, and there is an actual clinical need for increasing the efficiency of anti-HIV drugs in terms of targeted delivery and controlled release. Tenofovir (TFV), a nucleotide-analog reverse transcriptase inhibitor, has gained wide acceptance as a drug for pre-exposure prophylaxis or treatment of HIV infection. In our study, we explored the potential of tenofovir disoproxil (TFD) adducts with block copolymers of poly(ethylene glycol) monomethyl ether and poly(ethylene phosphoric acid) (mPEG-b-PEPA) as candidates for developing a long-acting/controlled-release formulation of TFV. Two types of mPEG-b-PEPA with numbers of ethylene phosphoric acid (EPA) fragments of 13 and 49 were synthesized by catalytic ring-opening polymerization, and used for preparing four types of adducts with TFD. Antiviral activity of [mPEG-b-PEPA]TFD or tenofovir disoproxil fumarate (TDF) was evaluated using the model of experimental HIV infection in vitro (MT-4/HIV-1IIIB). Judging by the values of the selectivity index (SI), TFD exhibited an up to 14-fold higher anti-HIV activity in the form of mPEG-b-PEPA adducts, thus demonstrating significant promise for further development of long-acting/controlled-release injectable TFV formulations.

scholarly journals Hydrogel Nanofibers from Carboxymethyl Sago Pulp and Its Controlled Release Studies as a Methylene Blue Drug Carrier

Fibers ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 56 ◽  
Author(s):  
Nafeesa Mohd Kanafi ◽  
Norizah Abdul Rahman ◽  
Nurul Husna Rosdi ◽  
Hasliza Bahruji ◽  
Hasmerya Maarof
Keyword(s):  
Methylene Blue ◽  
Citric Acid ◽  
Controlled Release ◽  
Drug Carrier ◽  
Curing Temperature ◽  
Buffer Solution ◽  
Release Studies ◽  
Electrospinning Method ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The potential use of carboxymethyl sago pulp (CMSP) extracted from sago waste for producing hydrogel nanofibers was investigated as a methylene blue drug carrier. Sago pulp was chemically modified via carboxymethylation reaction to form carboxymethyl sago pulp (CMSP) and subsequently used to produce nanofibers using the electrospinning method with the addition of poly(ethylene oxide) (PEO). The CMSP nanofibers were further treated with citric acid to form cross-linked hydrogel. Studies on the percentage of swelling following the variation of citric acid concentrations and curing temperature showed that 89.20 ± 0.42% of methylene blue (MB) was loaded onto CMSP hydrogel nanofibers with the percentage of swelling 4366 ± 975%. Meanwhile, methylene blue controlled release studies revealed that the diffusion of methylene blue was influenced by the pH of buffer solution with 19.44% of MB released at pH 7.34 within 48 h indicating the potential of CMSP hydrogel nanofibers to be used as a drug carrier for MB.

pH-responsive microspheres encapsulated with iron oxide nanoaggregates for gastrointestinal delivery

2012 ◽  
Vol 27 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Young Ju Son ◽  
Hyuk Sang Yoo
Keyword(s):  
Iron Oxide ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Diblock Copolymer ◽  
Ph Responsive ◽  
Polymeric Microspheres ◽  
Intestinal Delivery ◽  
Poly Ethylene ◽  
The Stability

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.

scholarly journals Aqueous-based electrospun P(NIPAAm-co-AAc)/RSF medicated fibrous mats for dual temperature- and pH-responsive drug controlled release

RSC Advances ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 323-331 ◽  
Author(s):  
Juan Li ◽  
Jingxin Zhu ◽  
Lan Jia ◽  
Yanlong Ma ◽  
Haijuan Wu
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Ph Responsive ◽  
Drug Controlled Release

This paper presents a green friendly method for preparing dual temperature- and pH-responsive electrospun P(NIPAAm-co-AAc)/RSF fibrous mats for drug release.

scholarly journals Functional polyurethane nanomicelle with pH-responsive drug delivery property

e-Polymers ◽  
2018 ◽  
Vol 18 (5) ◽  
pp. 409-417 ◽  
Author(s):  
Yifan Song ◽  
Yun Chai ◽  
Kai Xu ◽  
Puyu Zhang
Keyword(s):  
Drug Delivery ◽  
Drug Loading ◽  
Acid Group ◽  
Hydrophobic Drug ◽  
Ph Responsive ◽  
Triggered Release ◽  
New Thought ◽  
Buffering Agent ◽  
Sensitive Property

AbstractA new functional pH-responsive polyurethane-based nanomicelle has been developed with BES-Na as the functional monomer, the buffering agent with tertiary amine, and sulfonic acid group was incorporated into the hydrophilic shell as the functional agent, which resulted in polyurethane nanosystem with pH-sensitive property. Folic acid (FA) was chosen as model hydrophobic drug to evaluate the loading and pH-triggered release of the PU micelles in vitro drug loading and release. The drug loading content (LC) and the encapsulation efficiency (EE) for FA-loaded micelles in phosphate-buffered solutions were 7.68% and 27.72%, respectively, and the largest accumulative drug release percentages in pH 6.8 and pH 5.0 were 79.17% and 89.83% in 24 h, respectively. A facile and versatile approach has been provided for the design and fabrication of smart nanovehicles for effective drug delivery and opens a new thought in the design and fabrication of biodegradable polyurethanes for next generation of nanomicellar systems.

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