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Mohiuddin A Quadir - One of the best experts on this subject based on the ideXlab platform.
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new side chain design for ph responsive Block Copolymers for drug delivery
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Priyanka Ray, Narendra Kale, Mohiuddin A QuadirAbstract:Abstract New molecular motifs that can act as pH-regulating triggers for amphiphilic, pH-sensitive Block Copolymers are investigated. Inspired by the mechanism of action of pH-indicators, such as methyl orange, and natural amino acids, we designed these Copolymers where either 4-Amino-4′-dimethylaminoazobenzene, AZB (pKa 3.4, an amine derivative of methyl orange), isoleucine, Ile (pKa 2.37 for carboxylic acid), or a statistical mixture of both were appended as side chains to the hydrophobic Block to act as pH-triggers. These new side chain motifs were identified with an aim to enhance the self-assembling properties of the Block Copolymers in terms of particle size and stability, drug encapsulation, and release. As the parent polymer, poly (ethylene) glycol-Block- poly (carbonate) (PEG-b-PC) of number average molecular weight 12.1 kDa was used. We observed that PEG-b-PC Block Copolymers, when engineered with AZB or Ile-type of pH-regulators appended as side chains to PC Blocks, formed self-assembled, spherical nanoparticles with hydrodynamic diameters ranging from 114 to 137 nm depending on copolymer composition. Critical aggregation concentrations (CAC) of the Block Copolymers were found to be governed by the type and content of side chains. We explored the use of these newly designed Block copolymer assemblies as drug carriers using gemcitabine (GEM) as a model cytotoxic drug generally used for pancreatic ductal adenocarcinoma (PDAC). We showed that AZB and Ile decorated copolymeric nanocarriers were able to encapsulate GEM at 13.8–28.8 % loading content and release the drug in a pH-dependent pattern. Drug-loaded nanocarriers showed cellular entry into PDAC cells in vitro and were found to exert cytotoxicity against these cells. Neither the Block Copolymers bearing AZB or Ile-type pH-responsive triggers, nor their self-assembled nanoparticles showed any cytotoxicity at usable concentrations, thereby reflecting the potentials of these molecular motifs for designing stimuli-responsive drug delivery nanosystems.
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new side chain design for ph responsive Block Copolymers for drug delivery
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Priyanka Ray, Narendra Kale, Mohiuddin A QuadirAbstract:Abstract New molecular motifs that can act as pH-regulating triggers for amphiphilic, pH-sensitive Block Copolymers are investigated. Inspired by the mechanism of action of pH-indicators, such as methyl orange, and natural amino acids, we designed these Copolymers where either 4-Amino-4'-dimethylaminoazobenzene, AZB (pKa 3.4, an amine derivative of methyl orange), isoleucine, Ile (pKa 2.37 for carboxylic acid), or a statistical mixture of both were appended as side chains to the hydrophobic Block to act as pH-triggers. These new side chain motifs were identified with an aim to enhance the self-assembling properties of these Block Copolymers in terms of particle size and stability, drug encapsulation and release. As the parent polymer, poly (ethylene) glycol-Block- poly (carbonate) (PEG-b-PC) of number average molecular weight 12.1 kDa was used. We observed that PEG-b-PC Block Copolymers, when engineered with AZB or Ile-type of pH-regulators appended as side chains to PC Blocks, formed self-assembled, spherical nanoparticles with hydrodynamic diameters ranging from 114 – 137 nm depending on copolymer composition. Critical aggregation concentrations (CAC) of the Block Copolymers were found to be governed by the type and content of side chains. We explored the use of these newly designed Block copolymer assemblies as drug carriers using gemcitabine (GEM) as a model cytotoxic drug generally used for pancreatic ductal adenocarcinoma (PDAC). We showed that AZB and Ile decorated copolymeric nanocarriers were able to encapsulate GEM at 13.8 to 28.8 % loading content and release the drug in a pH-dependent pattern. Drug-loaded nanocarriers showed cellular entry into PDAC cells in vitro and were found to exert cytotoxicity against these cells. Neither the Block Copolymers bearing AZB or Ile-type pH-responsive triggers, nor their self-assembled nanoparticles showed any cytotoxicity at usable concentrations, thereby reflecting the potentials of these molecular motifs for designing stimuli-responsive drug delivery nanosystems.
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peg polypeptide Block Copolymers as ph responsive endosome solubilizing drug nanocarriers
Molecular Pharmaceutics, 2014Co-Authors: Mohiuddin A Quadir, Stephen W Morton, Kevin E Shopsowitz, Ryan Murphy, Thomas H. Epps, Zhou J. Deng, Paula T. HammondAbstract:Herein we report the potential of click chemistry-modified polypeptide-based Block Copolymers for the facile fabrication of pH-sensitive nanoscale drug delivery systems. PEG–polypeptide Copolymers with pendant amine chains were synthesized by combining N-carboxyanhydride-based ring-opening polymerization with post-functionalization using azide–alkyne cycloaddition. The synthesized Block Copolymers contain a polypeptide Block with amine-functional side groups and were found to self-assemble into stable polymersomes and disassemble in a pH-responsive manner under a range of biologically relevant conditions. The self-assembly of these Block Copolymers yields nanometer-scale vesicular structures that are able to encapsulate hydrophilic cytotoxic agents like doxorubicin at physiological pH but that fall apart spontaneously at endosomal pH levels after cellular uptake. When drug-encapsulated copolymer assemblies were delivered systemically, significant levels of tumor accumulation were achieved, with efficacy a...
Chuanbing Tang - One of the best experts on this subject based on the ideXlab platform.
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cobaltocenium containing Block Copolymers ring opening metathesis polymerization self assembly and precursors for template synthesis of inorganic nanoparticles
Macromolecular Rapid Communications, 2012Co-Authors: Lixia Ren, Christopher G Hardy, Jiuyang Zhang, Chuanbing TangAbstract:Side-chain cobaltocenium-containing Block Copolymers are prepared by ring-opening metathesis polymerization (ROMP). These Block Copolymers include one cobaltocenium-containing Block, with the second Block being either a nonmetal-containing segment or a cobaltocenium-containing segment with different counterions. These Block Copolymers are self-assembled into spherical core/shell micelles in solutions. A template strategy is used to prepare cobalt (II or III)-containing nanoparticles by treating the self-assembled micelles via UV/ozonolysis and pyrolysis. Characterization by X-ray photon spectroscopy and X-ray diffraction indicates that these nanoparticles consist of different oxidants of cobalt, depending on the chemical compositions of Block Copolymers.
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robust control of microdomain orientation in thin films of Block Copolymers by zone casting
Journal of the American Chemical Society, 2011Co-Authors: Chuanbing Tang, Detlef-m. Smilgies, Wei Wu, Tomasz KowalewskiAbstract:Block Copolymers with chemically immiscible segments exhibit a variety of microphase-separated nanostructures on the scale of 10–100 nm. Controlling the orientation of these microphase separated nanostructures is vital in many applications such as lithography, membranes, data storage, and so forth. Typical strategies involve the use of external fields or patterned substrates. Here, we report a robust zone casting technique to achieve highly ordered thin films of Block Copolymers on centimeter-scale substrates. The robustness of this technique is its powerful control on diverse morphologies and exceptional tolerance on versatility of Block copolymer chemistry as well as allowance of a wide spectrum of substrates. We demonstrate that perpendicular orientations with respect to the surface are achieved for Block Copolymers with both lamellar and cylindrical morphologies by controlling solution casting rate, temperatures, and Block copolymer chemical structures. Thin films of both noncrystalline and crystallin...
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renewable rosin acid degradable caprolactone Block Copolymers by atom transfer radical polymerization and ring opening polymerization
Macromolecules, 2010Co-Authors: Perry A Wilbon, Yijun Zheng, Chuanbing TangAbstract:Renewable rosin acid-degradable caprolactone Block Copolymers were prepared by atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP). Two-step sequential polymerization using either poly(2-acryloyloxyethyl dehydroabietic carboxylate)-OH (PAEDA-OH) or poly(e-caprolactone)-Br (PCL-Br) as macroinitiators resulted in well-defined Block Copolymers with low polydispersity. One-pot polymerization was carried out with three different sequential feeds of AEDA and e-CL monomers. The control of one-pot polymerization depended on the interactions of coexisting ATRP catalysts and ROP catalysts. While the minimal interactions between copper(I) and tin(II) catalysts produced well-defined Block Copolymers, excess copper(II) or tin(II) led to the formation of Block Copolymers with polydispersity >1.5. It was suggested that the tin(II) catalysts reduced the persistent radicals copper(II) of ATRP, leading to a poorly controlled polymerization. PCL segments of the Block Copolymers exhibited excell...
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synthesis and solution self assembly of side chain cobaltocenium containing Block Copolymers
Journal of the American Chemical Society, 2010Co-Authors: Lixia Ren, Christopher G Hardy, Chuanbing TangAbstract:The synthesis of side-chain cobaltocenium-containing Block Copolymers and their self-assembly in solution was studied. Highly pure monocarboxycobaltocenium was prepared and subsequently attached to side chains of poly(tert-butyl acrylate)-Block-poly(2-hydroxyethyl acrylate), yielding poly(tert-butyl acrylate)-Block-poly(2-acryloyloxyethyl cobaltoceniumcarboxylate). The cobaltocenium Block Copolymers exhibited vesicle morphology in the mixture of acetone and water, while micelles of nanotubes were formed in the mixture of acetone and chloroform.
Priyanka Ray - One of the best experts on this subject based on the ideXlab platform.
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new side chain design for ph responsive Block Copolymers for drug delivery
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Priyanka Ray, Narendra Kale, Mohiuddin A QuadirAbstract:Abstract New molecular motifs that can act as pH-regulating triggers for amphiphilic, pH-sensitive Block Copolymers are investigated. Inspired by the mechanism of action of pH-indicators, such as methyl orange, and natural amino acids, we designed these Copolymers where either 4-Amino-4′-dimethylaminoazobenzene, AZB (pKa 3.4, an amine derivative of methyl orange), isoleucine, Ile (pKa 2.37 for carboxylic acid), or a statistical mixture of both were appended as side chains to the hydrophobic Block to act as pH-triggers. These new side chain motifs were identified with an aim to enhance the self-assembling properties of the Block Copolymers in terms of particle size and stability, drug encapsulation, and release. As the parent polymer, poly (ethylene) glycol-Block- poly (carbonate) (PEG-b-PC) of number average molecular weight 12.1 kDa was used. We observed that PEG-b-PC Block Copolymers, when engineered with AZB or Ile-type of pH-regulators appended as side chains to PC Blocks, formed self-assembled, spherical nanoparticles with hydrodynamic diameters ranging from 114 to 137 nm depending on copolymer composition. Critical aggregation concentrations (CAC) of the Block Copolymers were found to be governed by the type and content of side chains. We explored the use of these newly designed Block copolymer assemblies as drug carriers using gemcitabine (GEM) as a model cytotoxic drug generally used for pancreatic ductal adenocarcinoma (PDAC). We showed that AZB and Ile decorated copolymeric nanocarriers were able to encapsulate GEM at 13.8–28.8 % loading content and release the drug in a pH-dependent pattern. Drug-loaded nanocarriers showed cellular entry into PDAC cells in vitro and were found to exert cytotoxicity against these cells. Neither the Block Copolymers bearing AZB or Ile-type pH-responsive triggers, nor their self-assembled nanoparticles showed any cytotoxicity at usable concentrations, thereby reflecting the potentials of these molecular motifs for designing stimuli-responsive drug delivery nanosystems.
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new side chain design for ph responsive Block Copolymers for drug delivery
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Priyanka Ray, Narendra Kale, Mohiuddin A QuadirAbstract:Abstract New molecular motifs that can act as pH-regulating triggers for amphiphilic, pH-sensitive Block Copolymers are investigated. Inspired by the mechanism of action of pH-indicators, such as methyl orange, and natural amino acids, we designed these Copolymers where either 4-Amino-4'-dimethylaminoazobenzene, AZB (pKa 3.4, an amine derivative of methyl orange), isoleucine, Ile (pKa 2.37 for carboxylic acid), or a statistical mixture of both were appended as side chains to the hydrophobic Block to act as pH-triggers. These new side chain motifs were identified with an aim to enhance the self-assembling properties of these Block Copolymers in terms of particle size and stability, drug encapsulation and release. As the parent polymer, poly (ethylene) glycol-Block- poly (carbonate) (PEG-b-PC) of number average molecular weight 12.1 kDa was used. We observed that PEG-b-PC Block Copolymers, when engineered with AZB or Ile-type of pH-regulators appended as side chains to PC Blocks, formed self-assembled, spherical nanoparticles with hydrodynamic diameters ranging from 114 – 137 nm depending on copolymer composition. Critical aggregation concentrations (CAC) of the Block Copolymers were found to be governed by the type and content of side chains. We explored the use of these newly designed Block copolymer assemblies as drug carriers using gemcitabine (GEM) as a model cytotoxic drug generally used for pancreatic ductal adenocarcinoma (PDAC). We showed that AZB and Ile decorated copolymeric nanocarriers were able to encapsulate GEM at 13.8 to 28.8 % loading content and release the drug in a pH-dependent pattern. Drug-loaded nanocarriers showed cellular entry into PDAC cells in vitro and were found to exert cytotoxicity against these cells. Neither the Block Copolymers bearing AZB or Ile-type pH-responsive triggers, nor their self-assembled nanoparticles showed any cytotoxicity at usable concentrations, thereby reflecting the potentials of these molecular motifs for designing stimuli-responsive drug delivery nanosystems.
Tota Rajasekhar - One of the best experts on this subject based on the ideXlab platform.
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Block Copolymers of poly e caprolactone with ph responsive side chain amino acid moieties
Journal of Polymers and The Environment, 2021Co-Authors: Venkanna Azmeera, Ujjal Haldar, Tota Rajasekhar, Saswati Ghosh RoyAbstract:To prepare amphiphilic Block Copolymers consisting of biocompatible and biodegradable segments, herein we report synthesis of diBlock Copolymers having e-caprolactone (e-CL) repeating units in one Block and amino acid-based acrylate monomers in another segment. The Block Copolymers were prepared by a combination of metal-free ring-opening polymerization (ROP) of e-CL and reversible addition-fragmentation chain transfer (RAFT) polymerization of tert-butyloxycarbonyl (Boc)-alanine/Boc-leucine based acrylate monomers. The ROP of e-CL was initiated with diphenyl phosphate (DPP) as a metal-free catalyst in conjunction with a heterofunctional initiator, benzyl-2-hydroxyethyl carbonotrithioate, produced trithiocarbonate terminated poly(e-caprolactone) (PCL). This was further employed as macro-chain transfer agent for the synthesis of side chain amino acid containing Block via RAFT. Deprotection of Boc group pendants from the Block Copolymers under acidic conditions at room temperature provided pH responsive Block Copolymers with positively charged cationic primary amine functionalities. Furthermore, self-assembling nature of these Block Copolymers in aqueous medium was examined through dynamic light scattering (DLS) and field emission-scanning electron microscopy (FE-SEM).
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Block Copolymers of poly e caprolactone with ph responsive side chain amino acid moieties
Journal of Polymers and The Environment, 2020Co-Authors: Venkanna Azmeera, Ujjal Haldar, Tota Rajasekhar, Priyadarsi DeAbstract:To prepare amphiphilic Block Copolymers consisting of biocompatible and biodegradable segments, herein we report synthesis of diBlock Copolymers having e-caprolactone (e-CL) repeating units in one Block and amino acid-based acrylate monomers in another segment. The Block Copolymers were prepared by a combination of metal-free ring-opening polymerization (ROP) of e-CL and reversible addition-fragmentation chain transfer (RAFT) polymerization of tert-butyloxycarbonyl (Boc)-alanine/Boc-leucine based acrylate monomers. The ROP of e-CL was initiated with diphenyl phosphate (DPP) as a metal-free catalyst in conjunction with a heterofunctional initiator, benzyl-2-hydroxyethyl carbonotrithioate, produced trithiocarbonate terminated poly(e-caprolactone) (PCL). This was further employed as macro-chain transfer agent for the synthesis of side chain amino acid containing Block via RAFT. Deprotection of Boc group pendants from the Block Copolymers under acidic conditions at room temperature provided pH responsive Block Copolymers with positively charged cationic primary amine functionalities. Furthermore, self-assembling nature of these Block Copolymers in aqueous medium was examined through dynamic light scattering (DLS) and field emission-scanning electron microscopy (FE-SEM).
Narendra Kale - One of the best experts on this subject based on the ideXlab platform.
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new side chain design for ph responsive Block Copolymers for drug delivery
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Priyanka Ray, Narendra Kale, Mohiuddin A QuadirAbstract:Abstract New molecular motifs that can act as pH-regulating triggers for amphiphilic, pH-sensitive Block Copolymers are investigated. Inspired by the mechanism of action of pH-indicators, such as methyl orange, and natural amino acids, we designed these Copolymers where either 4-Amino-4′-dimethylaminoazobenzene, AZB (pKa 3.4, an amine derivative of methyl orange), isoleucine, Ile (pKa 2.37 for carboxylic acid), or a statistical mixture of both were appended as side chains to the hydrophobic Block to act as pH-triggers. These new side chain motifs were identified with an aim to enhance the self-assembling properties of the Block Copolymers in terms of particle size and stability, drug encapsulation, and release. As the parent polymer, poly (ethylene) glycol-Block- poly (carbonate) (PEG-b-PC) of number average molecular weight 12.1 kDa was used. We observed that PEG-b-PC Block Copolymers, when engineered with AZB or Ile-type of pH-regulators appended as side chains to PC Blocks, formed self-assembled, spherical nanoparticles with hydrodynamic diameters ranging from 114 to 137 nm depending on copolymer composition. Critical aggregation concentrations (CAC) of the Block Copolymers were found to be governed by the type and content of side chains. We explored the use of these newly designed Block copolymer assemblies as drug carriers using gemcitabine (GEM) as a model cytotoxic drug generally used for pancreatic ductal adenocarcinoma (PDAC). We showed that AZB and Ile decorated copolymeric nanocarriers were able to encapsulate GEM at 13.8–28.8 % loading content and release the drug in a pH-dependent pattern. Drug-loaded nanocarriers showed cellular entry into PDAC cells in vitro and were found to exert cytotoxicity against these cells. Neither the Block Copolymers bearing AZB or Ile-type pH-responsive triggers, nor their self-assembled nanoparticles showed any cytotoxicity at usable concentrations, thereby reflecting the potentials of these molecular motifs for designing stimuli-responsive drug delivery nanosystems.
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new side chain design for ph responsive Block Copolymers for drug delivery
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Priyanka Ray, Narendra Kale, Mohiuddin A QuadirAbstract:Abstract New molecular motifs that can act as pH-regulating triggers for amphiphilic, pH-sensitive Block Copolymers are investigated. Inspired by the mechanism of action of pH-indicators, such as methyl orange, and natural amino acids, we designed these Copolymers where either 4-Amino-4'-dimethylaminoazobenzene, AZB (pKa 3.4, an amine derivative of methyl orange), isoleucine, Ile (pKa 2.37 for carboxylic acid), or a statistical mixture of both were appended as side chains to the hydrophobic Block to act as pH-triggers. These new side chain motifs were identified with an aim to enhance the self-assembling properties of these Block Copolymers in terms of particle size and stability, drug encapsulation and release. As the parent polymer, poly (ethylene) glycol-Block- poly (carbonate) (PEG-b-PC) of number average molecular weight 12.1 kDa was used. We observed that PEG-b-PC Block Copolymers, when engineered with AZB or Ile-type of pH-regulators appended as side chains to PC Blocks, formed self-assembled, spherical nanoparticles with hydrodynamic diameters ranging from 114 – 137 nm depending on copolymer composition. Critical aggregation concentrations (CAC) of the Block Copolymers were found to be governed by the type and content of side chains. We explored the use of these newly designed Block copolymer assemblies as drug carriers using gemcitabine (GEM) as a model cytotoxic drug generally used for pancreatic ductal adenocarcinoma (PDAC). We showed that AZB and Ile decorated copolymeric nanocarriers were able to encapsulate GEM at 13.8 to 28.8 % loading content and release the drug in a pH-dependent pattern. Drug-loaded nanocarriers showed cellular entry into PDAC cells in vitro and were found to exert cytotoxicity against these cells. Neither the Block Copolymers bearing AZB or Ile-type pH-responsive triggers, nor their self-assembled nanoparticles showed any cytotoxicity at usable concentrations, thereby reflecting the potentials of these molecular motifs for designing stimuli-responsive drug delivery nanosystems.