Chitosan Self-assembled

Park JS, Han TH, Lee KY, Han SS, Hwang JJ, Moon DH, Kim SY, Cho YW. N-acetyl histidine-conjugated glycol chitosan self-assembled nanoparticles for intracytoplasmic delivery of drugs Endocytosis, exocytosis and drug release. J Control Release 2006 115 37-45. 

N-acetyl histidine-conjugated glycol chitosan self-assembled NPs For intracytoplasmic delivery of drugs [162]... 

Li Y, Zhang S, Meng X, Chen X, Ren G. The preparation and characterization of a novel amphiphilic oleoyl-carboxymethyl chitosan self-assembled nanoparticles. Carbohydr Polym. 2011 83(l) 130-6. 

Park JH, Kwona S, Nam JO et al (2004) Self-assembled nanoparticles based on glycol chitosan bearing 5h-cholanic acid for RGD peptide delivery. J Control Release 95 579-588... 

Hajdu I, Bodnar M, Filipcsei G et al (2009) Nanoparticles prepared by self-assembly of chitosan and poly-y-glutamic acid. Colloid Polym Sci 286 343-350... 

Moreover, it has been demonstrated that CNTs promote the direct electrochemistry of enzymes. Dong and coworkers have reported the direct electrochemistry of microperoxidase 11 (MP-11) using CNT-modified GC electrodes [101] and layer-by-layer self-assembled films of chitosan and CNTs [102], The immobilized MP-11 has retained its bioelectrocatalytic activity for the reduction of H202 and 02, which can be used in biosensors or biofuel cells. The direct electrochemistry of catalase at the CNT-modified gold and GC electrodes has also been reported [103-104], The electron transfer rate involving the heme Fe(III)/Fe(II) redox couple for catalase on the CNT-modified electrode is much faster than that on an unmodified electrode or other... 

Even newer generations of nanomaterials are based on carbon nanotubes using the bottom-up approach. The materials are still very expensive, but the technology is evolving rapidly. Another type of nanotube has been prepared based on self-assembly of specific molecules such as chitosan-based nanoparticles of polypeptides, DNA or synthetic polymers. Phospholipids or dendrimer-coated particles are suitable for the entrapment of actives in very small vesicles. The current materials are still lacking in selectivity and yield (costs). 

Zhang, C., Ping, Q.E., Zhang, H. (2004). Self-assembly and characterization of paclitaxel-loaded N-octyl-O-sulfate chitosan micellar system. Colloids and Surfaces B Biointerfaces, 39, 69-75. 

Grant, J., Cho, J., Allen, C. (2006). Self-assembly and physicochemical and rheological properties of a polysaccharide-surfactant system formed front the cationic biopolymer chitosan and nonionic sorbitan esters. Langmuir, 22,4327- 4335. 

Cai et al. [28] have synthesised AuNPs-labelled ssDNA as a probe to be hybridised with their complementary strand on chitosan-modified glassy carbon electrode (GCE). In their experiments, SH-ssDNA was self-assembled onto an AuNP (16 nm in diameter) (details given previously in Ref. [54]). After hybridisation, the AuNPs tags were detected by differential pulse voltammetry (DPV). The detection limit was 1.0 x 10-9 mol L 1 of 32-base synthesised complementary oligonucleotide. 

Electrostatic self-assembly was combined with supramolecular chemistry to obtain inclusion complexes of a polymeric nonlinear optical (NLO) active dye and modified [3-cyclodextrin with induced chromophore orientation [37], The polyanion is a N,N-diallyl-aniline and sodium-2-acrylamido-2-methylpropanesulfonate copolymer functionalized with pendant azo group. The modified /i-cyclodextrin oligo-cation was obtained by treatment of hcptakis(6-dco y-6-iodo-/i-cyclodcxtrin) with excess pyridine. A linear polyamine, chitosan, was also combined with the polyanion, for comparison. Films were deposited on glass slides by dipping them alternatively in aqueous solutions of the cation and the polyanion. UV-visible spectra indicate dye aggregation and suggest the formation of an inclusion complex of the dye with the cyclodextrin, thus isolating the chromophores. 

Mi, F. L., Y. Y. Wu, et al. (2008). Oral delivery of peptide drugs using nanoparticles self-assembled by poly(gamma-glutamic acid) and a chitosan derivative functionalized by trimethylation. Bioconjug Chem 19(6) 1248-55. 

Sriamornsak P, Thirawong N, Nunthanid J, Puttipipatkhachorn S, Thongborisute J, Takeu-chi H (2008) Atomic force microscopy imaging of novel self-assembling pectin-liposome nanocomplexes. Carbohydr Polym 71 (2) 324—329 Takeuchi H, Yamamoto H, Niwa T, Hino T, Kawashima Y (1994) Mucoadhesion of polymer-coated liposomes to rat intestine in vitro. Chem Pharm Bull 42(9) 1954-1956 Takeuchi H, Yamamoto H, Niwa K, Hino T, Kawashima Y (1996) Enteral absorption of insulin in rats from mucoadhesive chitosan-coated liposomes. Pharm Res 13 896-901 Takeuchi H, Kojima H, Yamamoto H, Kawashima Y (2000) Polymer coating of liposomes with a modified polyvinyl alcohol and their systemic circulation and RES uptake in rats. J Control Rel 68(2) 195-205... 

Kwon, S. Park, J.H. Chung, H. Kwon, I.C. Jeong, S.Y. Kim, I.S. Physicochemcial characteristics of self-assembled nanoparticles based on glycol chitosan bearing 5beta-cholanic acid. Langmuir 2003, 19, 10,188-10,193. 

Self-assembled polymeric and oligomeric chitosan/DNA complex is formed by mixing chitosan with plasmid DNA was first reported by Mumper et al. in... 

Hyung Park J, Kwon S, Lee M (2006). Self-assembled nanoparticles based on glycol chitosan bearing hydrophobic moieties as carriers for doxorubicin In vivo biodistribution and anti-tumor activity. Biomaterials. 27 119-126. 

Opanasopit P, Ngawhirunpat T et al (2007) Camptothecin-incorporating N-phthaloyl-chitosan-g-mPEG self-assembly micellar system effect of degree of deacetylation. Colloids Surf B 60 117-124... 

Park K, Kim JH et al (2007) Effect of polymer molecular weight on the tumor targeting characteristics of self-assembled glycol chitosan nanoparticles. J Control Release 122 305-314... 

Liu L, Xu X et al (2009) Synthesis and self-assembly of chitosan-based copolymer with a pair of hydrophobic/hydrophilic grafts of polycaprolactone and poly(ethylene glycol). Carbohydr Polym 75 401 07... 

Ngawhimnpat T, Wonglertnirant N et al (2009) Incorporation methods for cholic acid chitosan-g-mPEG self-assembly micellar system containing camptothecin. Colloids Surf B 74 253-259... 

Chen C, Cal GQ et al (2011) Chitosan-poly(epsllon-caprolactone)-poly(ethylene glycol) graft copolymers synthesis, self-assembly, and drug release behavior. J Biomed Mater Res A 96A 116-124... 

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