Bioinspired and Multifunctional Phospholipid Polymer Nanoparticles

2016 ◽  
Vol 102 ◽  
pp. 3-11
Author(s):  
Kazuhiko Ishihara ◽  
Wei Xin Chen ◽  
Yuuki Inoue

Photoreactive and cytocompatible polymer nanoparticles for immobilizing and photoinduced releasing proteins were prepared. A water-soluble and amphiphilic phospholipid polymer, poly (2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-4-(4-(1-methacryloyloxyethyl)-2-methoxy-5-nitrophenoxy) butyric acid (PL)) (PMB-PL) was synthesized. The PMB-PL underwent a cleavage reaction at the PL unit by photoirradiation at a wavelength of 365 nm. Additionally, the PMB-PL took polymer aggregate in aqueous medium and was used to modify the surface of biodegradable poly (L-lactic acid) (PLA) nanoparticle as an emulsifier. The morphology of the PMB-PL/PLA nanoparticle was spherical and approximately 130 nm in diameter. The carboxylic acid group in the PL unit could be used for immobilization of proteins by covalent bonding. The bound proteins were released by a photoinduced cleavage reaction. Within 60 sec, up to 90% of the immobilized proteins were released by photoirradiation and activity of the protein released in the medium was maintained as well as that the original proteins before immobilization. Octa-arginine (R8) could promote internalization of the protein/PLA/PMB-PL nanoparticles into cells when the R8 was co-immobilized on the nanoparticles. After that, photoirradiation induced protein release from the nanoparticles and proteins distributed more evenly inside cells. From these results, we concluded that PMB-PL/PLA nanoparticles have the potential to be used as smart carriers to deliver proteins to biological systems, such as the inside of living cells.

2007 ◽  
Vol 342-343 ◽  
pp. 785-788
Author(s):  
Tomomi Ito ◽  
Tomohiro Konno ◽  
Madoka Takai ◽  
Kazuhiko Ishihara

We investigated the bioconjugation of proteins on polymer nanoparticles covered with bio-inert phosphorylcholine groups. Poly[2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate-co-p-nitrophenyloxycarbonyl polyethyleneglycol methacrylate] was used as an emulsifier and a surface modifier to prepare the poly (L-lactic acid) nanoparticles by a solvent evaporation technique. The diameter and surface potential of the nanoparticles were approximately 260 nm and –5 mV, respectively. We considered that the polymer chain that transformed the conformation by change in pH may be used as a method of controlling the bioreaction. The enzyme activity in a different pH under the coexistence of poly (glutamic acid) (PGA) and the enzyme was measured. Therefore, the enzyme activity increased in pH 6 in PGA/enzyme mixture system compared with that in pH 7 while the activity was constant in the enzyme single conjugation regardless of the pH change.


2006 ◽  
Vol 62 (7) ◽  
pp. o2751-o2752 ◽  
Author(s):  
Ting Sun ◽  
Jian-Ping Ma ◽  
Ru-Qi Huang ◽  
Yu-Bin Dong

In the title compound, C10H7N3O4·H2O, one carboxyl group is deprotonated and the pyridyl group is protonated. The inner salt molecule has a planar structure, apart from the carboxylic acid group, which is tilted from the imidazole plane by a small dihedral angle of 7.3 (3)°.


2011 ◽  
Vol 392 (11) ◽  
Author(s):  
Riyad Domingo ◽  
Kelly Chibale ◽  
Edward D. Sturrock

Abstract Matrix metalloproteinases (MMPs) cleave and degrade most components of the extracellular matrix, and unregulated MMP activity has been correlated to cancer and metastasis. Hence there is a burgeoning need to develop inhibitors that bind selectively to structurally similar MMPs. The inhibition profiles of peptidomimetics containing Cα substituents at the α,β unsaturated carbon were evaluated against the recombinant forms of ADAM17, MMP1, and MMP9. The dicarboxylic acid D2 and hydroxamate C2 inhibited MMP9 but not MMP1. The unsaturated compound E2 displayed selective inhibition for MMP1, compared with the saturated precursor C2, with an IC50 value of 3.91 μm. The molecular basis for this selectivity was further investigated by the molecular docking of E2 and D2 into the active sites of MMP1 and MMP9. These data demonstrate hydrogen-bonding interactions between the carbonyl group of the Cα substituent of E2 and the side chain of Asn180 present in the active site of MMP1. Conversely, the docked MMP9-D2 structure shows hydrophobic and hydrogen bonding between the ligand’s morpholine substituent and second carboxylic acid group with Leu187 and an amide, respectively. This study suggests that substituents other than P1′ and P2′ may confer selectivity among MMPs and may aid in the search for novel lead compounds.


2001 ◽  
Vol 711 ◽  
Author(s):  
Alexander Zelikin ◽  
Venkatram Shastri ◽  
David Lynn ◽  
Jian Farhadi ◽  
Ivan Martin ◽  
...  

ABSTRACTConductive polymers such as polypyrrole (Ppy) are potentially useful as an active interface for altering cellular processes and function. Their utilization in medically related applications however have been substantially held back by their non-degradable nature. Herein we report a novel approach to creation of bioerodible polypyrroles via modification of pyrrole beta-carbon with an ionizable moiety. It has been shown that the erosion rate of acid-bearing derivative of polypyrrole increases with pH, which is consistent with the pH dependent ionization of carboxylic acid group. The novel paradigm proposed for the creation of bioerodible polypyrroles allows for simple and efficient control over the erosion rate of the substrate independent of the polymer chain length, via the choice of the terminal ionizable group and its concentration along the polymer backbone.


2014 ◽  
Vol 70 (12) ◽  
pp. o1242-o1243 ◽  
Author(s):  
Wei Tang ◽  
Neng-Hua Chen ◽  
Guo-Qiang Li ◽  
Guo-Cai Wang ◽  
Yao-Lan Li

The title compound [systematic name: 3β-hydroxylup-20(29)-en-28-oic acid methanol monosolvate], C30H48O3·CH3OH, is a solvent pseudopolymorph of a naturally occurring plant-derived lupane-type pentacyclic triterpenoid, which was isolated from the traditional Chinese medicinal plantSyzygium jambos(L.) Alston. The dihedral angle between the planes of the carboxylic acid group and the olefinic group is 12.17 (18)°. TheA/B,B/C,C/DandD/Ering junctions are alltrans-fused. In the crystal, O—H...O hydrogen bonds involving the hydroxy and carboxylic acid groups and the methanol solvent molecule give rise to a two-dimensional network structure lying parallel to (001).


2012 ◽  
Vol 13 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Dongho Kim ◽  
Yoomi Yoon ◽  
Ildoo Chung ◽  
Chanyoung Park ◽  
Jongwoo Bae ◽  
...  

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