Jianbiao Ma

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Organization: Nankai University

Department: School of Chemistry and Chemical Engineering

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Polymer

Stimuli Responsive Polymers Polyesters PH Responsive Polymers Stimuli Responsive Polymers PH Responsive Polymers Temperature Responsive Polymers

Chemicals
References

Novel vanillic acid-based poly(ether–ester)s: from synthesis to properties

Co-reporter:Chengcai Pang, Jie Zhang, Qiufen Zhang, Guolin Wu, Yinong Wang and Jianbiao Ma

Polymer Chemistry 2015 vol. 6(Issue 5) pp:797-804

Publication Date(Web):30 Sep 2014

DOI:10.1039/C4PY01090F

Two series of bio-based poly(ether–ester)s from vanillic acid and linear α,ω-diols HO-(CH2)m-OH (m = 2, 3, 4, 10) have been successfully synthesized by the direct esterification method. These poly(ether–ester)s were characterized using FTIR, 1H-NMR, and size exclusion chromatography (SEC). Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used to study their thermo-mechanical properties. The poly(ether–ester)s had weight-average molecular weights (Mw) in the range of 16600 to 78700 g mol−1 and polydispersities between 1.39 and 2.00. All of the bio-based poly(ether–ester)s exhibited amorphous features with their glass transition temperatures (Tgs) ranging from 5 to 67 °C. The stress–strain parameters showed that the mechanical properties of these poly(ether–ester)s were excellent. The Young's modulus and elongation at break of the poly(ether–ester)s in this series were found to be in the range of 95–228 MPa and 14.9–311%, respectively.

Amino poly(glycerol methacrylate)s for oligonucleic acid delivery with enhanced transfection efficiency and low cytotoxicity

Co-reporter:Hui Gao, Xueyou Lu, Yanan Ma, Yingwei Yang, Jianfa Li, Guolin Wu, Yinong Wang, Yunge Fan and Jianbiao Ma

Soft Matter 2011 vol. 7(Issue 19) pp:9239-9247

Publication Date(Web):18 Aug 2011

DOI:10.1039/C1SM05756A

To improve the transfection activity and reduce cell cytotoxicity of polycations with antisense oligonucleotide (AON), poly(glycidyl methacrylate)s (PGMAs) were modified with different amines, i.e., methylethylamine (MEA), 2-amino-1-butanol (2-ABO) and 4-amino-1-butanol (4-ABO). The structures of resulting polymers were well characterized and their thermal properties were studied by differential scanning calorimetry (DSC). The amino PGMA could self-assemble with AON in a Tris buffer solution, resulting in narrowly distributed polymer/AON complexes with a size of 0.1–0.3 μm at an amine-group-of-polymer/phosphate-group-of-nucleotide ratio (N/P ratio) of 0.5–3. Spherical nanoparticles of the complexes were visualized using atomic force microscopy (AFM), and the gel electrophoresis and zeta potential assay evidenced the formation of complexes at relatively low N/P ratios. Stability of the complexes towards dissociation was tested using ethidium bromide displacement assay. Protection of the incorporated AON against DNase I degradation was also evaluated. An increased charge ratio and a synergistic effect of hydrogen bonding in this system contributed to the increased stability of the complex, which prevents the incorporated AON from nuclease degradation. In vitro cytotoxicity experiments on COS-7 cells showed that all amino PGMAs displayed lower toxicity compared to the control PEI25k, except for the polymers with a relatively high molecular weight (30 kDa). In addition, the MEA modified linear and star-shaped PGMA (Mn in the range of 15–20 kDa) as well as 4-ABO modified linear PGMA complexes exhibited higher transfection efficiencies in vitro, compared to PEI25k. These results demonstrated that amino PGMAs with suitable amine groups and molecular weight can be used as safe and efficient AON delivery polymers.

Synthesis of a novel zwitterionic biodegradable poly (α,β-l-aspartic acid) derivative with some l-histidine side-residues and its resistance to non-specific protein adsorption

Co-reporter:Xiaojuan Wang, Guolin Wu, Caicai Lu, Yinong Wang, Yunge Fan, Hui Gao, Jianbiao Ma

Colloids and Surfaces B: Biointerfaces 2011 Volume 86(Issue 1) pp:237-241

Publication Date(Web):1 August 2011

DOI:10.1016/j.colsurfb.2011.04.010

A novel zwitterionic polypeptide derivative, denoted as His-PAsp/PAsp, was successfully synthesized by amidation of Poly (α,β-l-aspartic acid) with l-histidine methyl ester. Turbidity, zeta potential and 1H NMR measurements were used to study the aggregation behaviors of His-PAsp/PAsp under different pH values. The modified polypeptide derivative composed of electro-negatively carboxylic and electro-positively imidazole residues randomly so as to bear opposite charges at pH values above or below the isoelectric point. When the zwitterionic polypeptide was coated on silicon wafer as a model substrate material, the absorption resistance of fibrinogen, a blood protein resulting in the blood coagulation cascade, on the coated surface was measured. It was found that the adsorption amount of fibrinogen on the polypeptide-coated surface depended on the dose of the polypeptide on silicon wafer. Obvious resistance of the fibrinogen adsorption on the polypeptide-coated surface was observed. Since its good biodegradability and superior anti-protein-fouling property, this pH-responsive zwitterionic polypeptide is a promising candidate for surface modification in many biomedical applications, including medical implants, drug delivery carriers, and biosensors.Graphical abstractHighlights► His-PAsp/PAsp zwitterionic polypeptide has been successfully synthesized by a facile way. ► The modified polypeptide derivative had an isoelectric point and bore opposite charges at pH values far high or below the isoelectric point. ► By the surface modification of zwitterionic polypeptide, the surface exhibited resistance to nonspeciﬁc protein adsorption.

Synthesis of amphiphilic poly(tetraethylene glycol succinate) and the thermosensitivity of its aggregation in water

Co-reporter:Shusen Chen;Yinong Wang;Yunge Fan

Journal of Biomedical Materials Research Part A 2009 Volume 88A( Issue 3) pp:769-777

Publication Date(Web):

DOI:10.1002/jbm.a.31909

Abstract

Amphiphilic biodegradable polyester, poly(tetraethylene glycol succinate) (PTEGSuc), was synthesized via melt polycondensation of tetraethylene glycol and succinic acid on catalysis of p-toluenesulfonic acid. It was observed that PTEGSuc could self-assemble into micelles in water. In addition, thermosensitivity of PTEGSuc aggregation in water was first found in the experiment, and the critical aggregation temperatures could be controlled by solution concentration. Transmission electron microscopy was used to investigate the micellar morphologies of PTEGSuc in different solvents. It was found that particle shape is almost round although the micellar morphology is different depending on the solvent used. Based on the perfect properties, especially in micelle formation and thermosensitivity, PTEGSuc is promising in biomedical field as carrier of drug delivery system, scaffold of tissue engineering, and other medical devices. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009

Potentiometric studies on the interaction between superoxide dismutase and hyaluronic acid

Co-reporter:Yaofeng Fan;Yinong Wang;Yunge Fan

Journal of Applied Polymer Science 2009 Volume 113( Issue 4) pp:2583-2589

Publication Date(Web):

DOI:10.1002/app.30238

Abstract

The formation process of soluble complexes and insoluble aggregates between superoxide dismutase (SOD) and hyaluronic acid (HA) was studied using quasielastic light scattering and turbidimetric titration. The electrostatic binding between them was investigated in detail through potentiometric titration and turbidimetric titration carried out from high to low pH. Turbidimetric titration was used to determine the specific pH values at which soluble complex formation was initiated (pH_c) and phase separation occurred (pH_ϕ). An increase of the ionic strength causes a decrease of pH_c and pH_ϕ. With the increase of HA concentrations, pH_ϕ increases but pH_c does not vary. The formed “salt bridges” between (SOD) and COO⁻ (HA) result in the formation of stable SOD-HA complexes and even aggregates. The necessary condition of electrostatic binding was also given for protein-acidic polyelectrolyte systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

pH-Responsive Self-Assembly and conformational transition of partially propyl-esterified poly(α,β-l-aspartic acid) as amphiphilic biodegradable polyanion

Co-reporter:Yong Wang, Yinong Wang, Guolin Wu, Yunge Fan, Jianbiao Ma

Colloids and Surfaces B: Biointerfaces 2009 Volume 68(Issue 1) pp:13-19

Publication Date(Web):1 January 2009

DOI:10.1016/j.colsurfb.2008.08.026

Poly(α,β-l-aspartate) (PAsp) was partially esterified to afford an amphiphilic biodegradable polyanion, poly(sodium aspartate-co-propyl aspartate) (PAsp-Na/PAsp-P). The synthesized polyanion could be assembled into the nano-scaled aggregates in aqueous medium. The aggregate morphologies were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) as a function of pH. It was demonstrated that micellization of this random copolymer occurred with stimulus of pH changes to form various morphological micelles. The copolymer existed as precipitate at low pH (pH < 2). When pH increased to 4, the polymers were associated into spherical micelles with the core of poly(propyl aspartate) (PAsp-P) hydrophobic units and shell of some negatively charged poly(sodium aspartate) (PAsp-Na) units. At higher pH (pH > 5), toroidal nanostructures of the micelles were formed because rigid polyamide chains directly assemble into the large hollow spheres. The CD study showed that the conformation underwent a transition between α-helix and random coil at pH 3–7. The cooperative transitions were regulated by the degree of ionization of carboxylic side chains. When they were protonated (neutralized), the molecular backbone was in favor of the regular helical structure; when deprotonated (ionized), the electrostatic repulsions among side chains destabilized the intramolecular hydrogen bonds, thus randomizing the regular conformation.

Ethylenediamino bridged bis(-cyclodextrin)/ poly(DL-lactic-co-glycolic acid) nanoparticles prepared by modified double emulsion method: Effect of polyvinyl alcohol on nanoparticle properties

Co-reporter:Hui Gao;Yinong Wang;Yunge Fan

Journal of Applied Polymer Science 2008 Volume 107( Issue 1) pp:

Publication Date(Web):

DOI:10.1002/app.26613

Abstract

This study continues long-standing efforts to develop protein delivery systems based on cyclodextrin-conjugated polyester in our laboratory. The crude products of ethylenediamino bridged bis(β-cyclodextrin)-conjugated poly(DL-lactic-co-glycolic acid) were used in this study to make full use of unreacted reactant. With bovine serum albumin (BSA) as a model protein, the encapsulation effects (the encapsulation efficiency and particle size) of nanoparticles were similar to those of using pure conjugated products. Besides, a water-in-oil-in-water emulsification technique was conveniently modified. By adding polyvinyl alcohol (PVA) in the internal aqueous phase, a more stabilized emulsion was formed. Consequently, less PVA (∼ 0.05%) was needed in the outer aqueous phase and less PVA (0.14 g/g nanoparticles) remained in the nanoparticles. This modification resulted in improved encapsulation efficiency (∼ 89–94%) of BSA and an enlarged particle size (340–390 nm). Furthermore, the burst release of BSA at the 1st day was less pronounced (7–12% of the encapsulated amount) than that of nanoparticles with no PVA added in the internal aqueous phase. Degradation studies using transmission electron microscope and gel permeation chromatography suggested that the mechanism for protein release was mainly through nanoparticles erosion. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Conjugates of poly(DL-lactide-co-glycolide) on amino cyclodextrins and their nanoparticles as protein delivery system

Co-reporter:Hui Gao;Yi-Nong Wang;Yun-Ge Fan;Jian-Biao Ma

Journal of Biomedical Materials Research Part A 2007 Volume 80A(Issue 1) pp:111-122

Publication Date(Web):7 SEP 2006

DOI:10.1002/jbm.a.30861

Poly(DL-lactide-co-glycolide) (PLG) was chemically conjugated on two amino cyclodextrins, mono(6-(2-aminoethyl)amino-6-deoxy)-β-cyclodextrin and ethylenediamino bridged bis(β-cyclodextrin), to afford novel amphiphilic conjugates. Those conjugates were then characterized with infrared spectrometry (IR), proton nuclear magnetic resonance (¹H NMR) and gel permeation chromatography (GPC). A repeat-nanoprecipitation (RP-NP) method was also developed to fabricate the nanoparticles of the conjugates with a water-soluble model protein, bovine serum albumin (BSA). At the end of RP-NP process, the availability of BSA was over 80% while the entrapment efficiency was 40–50% for each nanoprecipitation. The nanoparticles were rigid and spherical with diameters of 110–180 nm determined by transmission electron microscope (TEM), atomic force microscopy (AFM) and particle size analyzer. Nanoparticles possessed good steric stability during freeze-drying and resuspensions due to the existence of cyclodextrins corona. Interactions between BSA and the conjugates in the nanoparticles were then elucidated with IR experiments. About 25% BSA adsorbed on the surface of nanoparticles due to the interaction and was easy to release in the first day. The release of BSA from the nanoparticles was in three phases: a burst effect in the first day, a followed plateau in about a week, and a sustained release of the protein over 14 days. By changing the lactide/glycolide ratio, the degradation time of the conjugates and the release rate of BSA could be controlled. The loss of CDs content was faster than that of overall Mw during degradation since CDs formed outer corona of the nanoparticles. Both the novel biomaterials and the nanosphere fabrication technique contributed to the maintenance of protein structure. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007

Unexpected fluorescence emission of poly(α,β-L-malic acid) in aqueous medium

Co-reporter:Yunge Fan;Yaofeng Fan;Yinong Wang

Journal of Applied Polymer Science 2007 Volume 106(Issue 3) pp:1640-1647

Publication Date(Web):18 JUL 2007

DOI:10.1002/app.26713

Unexpected fluorescence of poly(α,β-L-malic acid) (α,β-PMA) without traditional fluorophore was observed firstly. This fluorescent polymer was synthesized via melt polycondensation of L-malic acid. The polymer was characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermogravimetry (TG), Fourier transform infrared spectroscopy (IR), Fourier transform Raman spectroscopy (Raman), and X-ray powder diffractometry (XRD). The high molecular weight α,β-PMA was synthesized by the optimum polycondensation at 130°C for 15 h, followed by fractional precipitation with diethyl ether and petroleum ether. The degree of branching of α,β-PMA was from 10% to 20% according to the reaction condition. Terminal group of α,β-PMA was mainly hydroxycarboxylic group companied with a few CHCHCOOH groups owing to dehydration of a normal terminal during the melt polycondensation. A fluorescence emission maximum of α,β-PMA in water appeared at 420 nm when it was excited at 340 nm. Further study indicated that the fluorescence intensity was concentration-dependent, pH-dependent, and molecular-weight-dependent. The fluorescence formation may result from multichain aggregations, which was formed readily in aqueous solution due to intermolecular hydrogen bonds between branched α,β-PMA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Thermal, physical and chemical stability of porous polystyrene-type beads with different degrees of crosslinking

Co-reporter:Yanhong Li, Yunge Fan, Jianbiao Ma

Polymer Degradation and Stability 2001 Volume 73(Issue 1) pp:163-167

Publication Date(Web):2001

DOI:10.1016/S0141-3910(01)00083-0

The thermal properties of porous polystyrene-type beads with different degrees of crosslinking by divinylbenzene were studied by thermogravimetry, differential scanning calorimetry, infrared spectroscopy and Raman spectroscopy. The results showed that thermal decomposition temperature of the beads was raised with increased crosslinking in the porous beads, suggesting that their thermal stability could be greatly improved by crosslinking as expected. DSC analysis revealed that porous beads with crosslinking degrees less than 30% (in weight) had a glass transition and that its temperature (Tg) was gradually changed from about 100°C (Tg of linear polystyrene) to 160°C as the crosslinking was increased. However, Tg disappeared and an exothermic peak around 165°C was found for highly crosslinked beads with more than 30% of crosslinking. The exothermic peak might be attributed to the coupling reaction and/or thermal polymerization of pendant double bonds at high temperature as proved by IR and Raman spectra. When crosslinking was less than 10%, a melting process could be observed as an endotherm at about 270°C. Otherwise, if the crosslinking was above 15%, no melting was displayed and instead of it an exothermic phenomenon took place between 250–350°C. The exotherm might be due to the decomposition of some groups formed in the preparation and storage of the beads.

A novel delivery system of doxorubicin with high load and pH-responsive release from the nanoparticles of poly (α,β-aspartic acid) derivative

Co-reporter:Xiaojuan Wang, Guolin Wu, Caicai Lu, Weipeng Zhao, Yinong Wang, Yunge Fan, Hui Gao, Jianbiao Ma

European Journal of Pharmaceutical Sciences (30 August 2012) Volume 47(Issue 1) pp:256-264

Publication Date(Web):30 August 2012

DOI:10.1016/j.ejps.2012.04.007

A poly (amino acid)-based amphiphilic copolymer was utilized to fabricate a better micellar drug delivery system (DDS) with improved compatibility and sustained release of doxorubicin (DOX). First, poly (ethylene glycol) monomethyl ether (mPEG) and DOX were conjugated onto polyasparihyazide (PAHy), prepared by hydrazinolysis of the poly (succinimide) (PSI), to afford an amphiphilic polymer [PEG-hyd-P (AHy-hyd-DOX)] with acid-liable hydrazone bonds. The DOX, chemically conjugated to the PAHy, was designed to supply hydrophobic segments. PEGs were also grafted to the polymer via hydrazone bonds to supply hydrophiphilic segments and prolong its lifetime in blood circulation. Free DOX molecules could be entrapped into the nanoparticles fabricated by such an amphiphilic polymer (PEG-hyd-P (AHy-hyd-DOX)), via hydrophobic interaction and π–π stacking between the conjugated and free DOX molecules to obtain a pH responsive drug delivery system with high DOX loaded. The drug loading capacity, drug release behavior, and morphology of the micelles were investigated. The biological activity of micelles was evaluated in vitro. The drug loading capacity was intensively augmented by adjusting the feed ratio, and the maximum loading capacity was as high as 38%. Besides, the DOX-loaded system exhibited pH-dependent drug release profiles in vitro. The cumulative release of DOX was much faster at pH 5.0 than that at pH 7.4. The DOX-loaded system kept highly antitumor activity for a long time, compared with free DOX. This easy-prepared DDS, with features of biocompatibility, biodegradability, high drug loading capacity and pH-responsiveness, was a promising controlled release delivery system for DOX.Download high-res image (129KB)Download full-size image