scholarly journals Synthesis of Water-Soluble Star Polymers Based on Cyclodextrins

2018 ◽  
pp. S357-S365
Author(s):  
L. KOTRCHOVÁ ◽  
T. ETRYCH
Keyword(s):  
Star Polymers ◽  
Water Soluble ◽  
Hpma Copolymer ◽  
Polymer Carriers ◽  
Physico Chemical ◽  
Reversible Addition ◽  
Degradation Rates ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide ◽  
Chain Transfer Polymerization

Novel star polymers based on the water-soluble N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer and cyclodextrin were synthesized and the physico-chemical behavior of these precursors was studied. Semitelechelic HPMA copolymers were grafted onto the cyclodextrin core, thus forming star-like structure. Both prepared systems were designed as possible polymer carriers for the controlled release of cytostatic drugs, which after the drug release and degradation will be eliminated from the organism. Two synthesis approaches were used to obtain similar polymer carriers with different degradation rates. All the polymers were prepared by reversible addition-fragmentation chain-transfer polymerization, which guarantees low dispersity of the prepared systems.

Synthesis and Photoproperties of a Substituted Zinc(II) Phthalocyanine-N-(2-hydroxypropyl)methacrylamide Copolymer Conjugate

1993 ◽  
Vol 58 (10) ◽  
pp. 2321-2336 ◽  
Author(s):  
Zhong-wei Gu ◽  
John D. Spikes ◽  
Pavla Kopečková ◽  
Jindřich Kopeček
Keyword(s):  
Organic Solvents ◽  
Water Soluble ◽  
Lower Probability ◽  
Hpma Copolymer ◽  
Polymeric Derivative ◽  
Oxygen Generation ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide ◽  
Polymeric Carriers ◽  
Thiol Proteinases

In cancer photodynamic therapy (PDT), improved efficiency of photosensitizer delivery to tumors may be obtained by binding them to targetable water soluble polymeric carriers. However, attachment of photosensitizers to Macromolecular carriers may alter their spectral and photosensitizing properties. In this study, a new monosubstituted phthalocyanine derivative, N-glycyl zinc(II) 4,9,16,23-tetraaminophthalocyanine (G-TAPC-Zn) was synthesized by the reaction of zinc(II) 4,9,16,23-tetraaminophthalocyanine (TAPC-Zn) with N-tert-butoxycarbonyl-glycine N'-hydroxybenzotriazole ester followed by deprotection of the tert-butoxycarbonyl (BOC) group. G-TAPC-Zn contains an aliphatic amino group suitable for attachment to water soluble polymeric carriers. By aminolysis of a polymeric precursor, an N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing oligopeptide (GFLG) side-chains terminated in p-nitrophenyl ester groups, with G-TAPC-Zn a polymeric derivative of the latter (P-GFLGG-TAPC-Zn) was synthesized. Spectral data indicated that in aqueous solutions P-GFLGG-TAPC-Zn formed aggregates. The degree of aggregation decreased with increasing concentration of detergents or organic solvents in buffer solutions. Consequently, the release of the drug from carrier catalyzed by thiol proteinases, papain or cathepsin B, took place only in the presence of detergents or organic solvents, i.e., under conditions with a lower probability of aggregate formation. Binding of G-TAPC-Zn to HPMA copolymers decreased the quantum yield of singlet oxygen generation from 0.24 to 0.063 and significantly increased its resistance to photobleaching.

scholarly journals Structure-to-Efficacy Relationship of HPMA-Based Nanomedicines: The Tumor Spheroid Penetration Study

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1242
Author(s):  
Júlia Kudláčová ◽  
Lenka Kotrchová ◽  
Libor Kostka ◽  
Eva Randárová ◽  
Marcela Filipová ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Drug Carrier ◽  
In Vitro Models ◽  
Hpma Copolymer ◽  
Polymer Carriers ◽  
Hydroxypropyl Methacrylamide ◽  
Tumor Accumulation ◽  
Structural Architecture ◽  
Relationship Of

Nanomedicines are a novel class of therapeutics that benefit from the nano dimensions of the drug carrier. These nanosystems are highly advantageous mainly within cancer treatment due to their enhanced tumor accumulation. Monolayer tumor cells frequently used in routine preclinical assessment of nanotherapeutics do not have a spatial structural architecture that allows the investigation of the penetration of nanomedicines to predict their behavior in real tumor tissue. Therefore, tumor spheroids from colon carcinoma C26 cells and glioblastoma U87-MG cells were used as 3D in vitro models to analyze the effect of the inner structure, hydrodynamic size, dispersity, and biodegradability of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-based nanomedicines carrying anticancer drug pirarubicin (THP) on the penetration within spheroids. While almost identical penetration through spheroids of linear and star-like copolymers and also their conjugates with THP was observed, THP penetration after nanomedicines application was considerably deeper than for the free THP, thus proving the benefit of polymer carriers. The cytotoxicity of THP-polymer nanomedicines against tumor cell spheroids was almost identical as for the free THP, whereas the 2D cell cytotoxicity of these nanomedicines is usually lower. The nanomedicines thus proved the enhanced efficacy within the more realistic 3D tumor cell spheroid system.

Pinocytic capture and exocytosis of rat immunoglobulin IgG-N-(2-hydroxy-propyl)methacrylamide copolymer conjugates by rat visceral yolk sacs cultured in vitro

1986 ◽  
Vol 6 (10) ◽  
pp. 869-877 ◽  
Author(s):  
Ruth Duncan ◽  
Hazel C. Cable ◽  
Jiri Strohalm ◽  
Jindřich Kopeček
Keyword(s):  
Drug Carrier ◽  
Yolk Sac ◽  
Membrane Receptors ◽  
Cellular Transport ◽  
Hpma Copolymer ◽  
Intracellular Degradation ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide ◽  
Covalently Bound

Rat immunoglobulin (IgG) was covalently bound to N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers via glycylglycyl spacer. The resultant conjugate, free IgG and HPMA copolymer (containing a low percentage of tyrosinamide to facilitate radiolabelling) were radioiodinated, and their rates of pinocytic uptake, intracellular degradation and exocytic release by rat visceral yolk sacs cultured in vitro were determined. Free IgG was pinocytosed rapidly by the yolk sac and some IgG was subject to intracellular proteolysis. In comparison the IgG-HPMA copolymer conjugate was captured more slowly, but faster than unmodified HPMA. IgG was also exocytosed rapidly by the yolk sac following pinocytic capture and similarly IgG-HPMA copolymer had a much higher rate of release than unmodified H PMA. Measurement of tissue accumulation of125I-labelled IgG-H PMA copolymer in the presence of increasing concentrations of non-radiolabelled IgG showed competition for membrane binding sites between the free, and polymer-bound immunoglobulin. These experiments indicate that immunoglobulins can be covalently bound to a soluble polymer developed as a drug-carrier in such a way that they can still interact with specific membrane receptors and they are subsequently subjected to specific cellular transport mechanisms.

Synthesis of polystyrene-based Y-shaped asymmetric star by the combination of ATRP/RAFT and its thermal and rheological properties

RSC Advances ◽  
2016 ◽  
Vol 6 (108) ◽  
pp. 106648-106655 ◽  
Author(s):  
Haiying Tan ◽  
Guangchun Zhang ◽  
Yichao Lin ◽  
Li Ma ◽  
Tao Tang
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Rheological Properties ◽  
Radical Polymerization ◽  
Chain Transfer ◽  
Star Polymers ◽  
Atom Transfer ◽  
Reversible Addition ◽  
Miktoarm Star ◽  
Chain Transfer Polymerization

A2A′-type asymmetric stars and A2B-type miktoarm star polymers were prepared by the combination of atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT) using the designed initiator.

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