Phase behavior of polyisoprene-poly(butylene oxide) and poly(ethylene-alt-propylene)-poly(butylene oxide) block copolymers

Soft Matter ◽  
2010 ◽  
Vol 6 (6) ◽  
pp. 1281 ◽  
Author(s):  
Ning Zhou ◽  
Timothy P. Lodge ◽  
Frank S. Bates
Keyword(s):  
Block Copolymers ◽  
Phase Behavior ◽  
Poly Ethylene

scholarly journals Hybrid Unilamellar Vesicles of Phospholipids and Block Copolymers with Crystalline Domains

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1232
Author(s):  
Yoo Kyung Go ◽  
Nurila Kambar ◽  
Cecilia Leal
Keyword(s):  
Phase Separation ◽  
Block Copolymers ◽  
Phase Behavior ◽  
Laser Scanning ◽  
Structural Phase ◽  
Dynamical Behavior ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Lamellar Phases ◽  
Poly Ethylene

Phospholipid (PL) membranes are ubiquitous in nature and their phase behavior has been extensively studied. Lipids assemble in a variety of structures and external stimuli can activate a quick switch between them. Amphiphilic block copolymers (BCPs) can self-organize in analogous structures but are mechanically more robust and transformations are considerably slower. The combination of PL dynamical behavior with BCP chemical richness could lead to new materials for applications in bioinspired separation membranes and drug delivery. It is timely to underpin the phase behavior of these hybrid systems and a few recent studies have revealed that PL–BCP membranes display synergistic structural, phase-separation, and dynamical properties not seen in pure components. One example is phase-separation in the membrane plane, which seems to be strongly affected by the ability of the PL to form lamellar phases with ordered alkyl chains. In this paper we focus on a rather less explored design handle which is the crystalline properties of the BCP component. Using a combination of confocal laser scanning microscopy and X-ray scattering we show that hybrid membranes of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG-b-PCL) display BCP-rich and PL-rich domains when the BCP comprises crystalline moieties. The packing of the hydrophilic part of the BCP (PEG) favors mixing of DPPC at the molecular level or into nanoscale domains while semi-crystalline and hydrophobic PCL moieties bolster microscopic domain formation in the hybrid membrane plane.

Phase behavior of low-functionality, telechelic star block copolymers

2010 ◽  
Vol 144 ◽  
pp. 143-157 ◽  
Author(s):  
Federica Lo Verso ◽  
Athanassios Z. Panagiotopoulos ◽  
Christos N. Likos
Keyword(s):  
Block Copolymers ◽  
Phase Behavior ◽  
Star Block Copolymers

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.

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