Chitosan succinate

Aiedeh, K., and Taha, M.O., Synthesis of chitosan succinate and chitosan phthalate and their evaluation as suggested matrices in orall administered, colon-specific drug delivery systems, Arch. Pharm (Weinheim), 332 103-107 (1999). 

Thus, our results demonstrated that the trends of selectivity for hydrogenation of 1,4-butenediol and cyclopentadiene are in tight connection with preliminary chitosan chemical modification as well as mineral support nature. Pd/chitosan modified with 2-pyridinealdehyde deposited on SiOa demonstrated high selectivity in hydrogenation of cyclopentadiene into cyclopentene. 1,4-butynediol into cis-l,4-butenediol hydrogenation proceeded very selectively over Pd-Pb catalytic systems based on chitosan succinate form. 

K. Aiedeh and M.O. Taha, Synthesis of iron-crosslinked chitosan succinate and iron-cross-linked hydroxamated chitosan succinate and their in vitro evaluation as potential matrix materials for oral theophylline sustained-release beads, Eur. J. Pharm. Sci., 13 159-168, 2001. 

Birlik et al. prepared double-imprinted chitosan beads which can be used for the selective removal of Cu (II) ions from synthetic waters [33]. Chitosan-succinate was mixed with Cu (II) ions and then reacted with 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS). Both Cu (II) and AAPTS were used as templates. After crosslinked with tetraethoxysilane, the Cu (II) ions were removed using HNO3 solution. Then the double-imprinted beads were formed. The double-imprinted beads were used in the adsorption-desorption of Cu (II) ions from metal solutions. The maximum adsorption capacity for Cu (II) ions was 47.63 mg/g. To increase metal loading capacities and selectivity, the double-imprinted beads were superior to the Cu (II)-imprinted chitosan-succinate. 

In addition, molecular imprinting technique is also used in anion recognition. Ozkutuk et al. reported the preparation and adsorption ability of the phosphate-imprinted chitosan-succinate beads [34]. Chitosan was modified with succinic anhydrides firstly. Second the mixture of chitosan-succinate and Fe (III) ions stirred continuously at room temperature. And Na3P04 was added to Fe (III)-chitosan-succinate mixture. This mixture was slowly dropped into NaOH solution to form beads. Afterwards, beads were crosslinked with epichlorohydrin and the template (phosphate ions) was removed using IM KOH solution. Selective cavity for the phosphate ion was obtained in the phosphate imprinted metal-chelate polymer. The phosphate-imprinted metal-chelate polymer was used in the adsorption-desorption process. The adsorption process was fast and equilibrium was reached around 30 min. The adsorption behaviour of this system was described approximately by the Langmuir equation. 

We initially prepared the first chitosan-sialoside hybrid 19 by treating 80% de-AT-acetylated chitosan with p-formylphenyl a-sialoside 6 (Scheme 1) under reductive amination conditions (NaBH3CN) (Scheme 7) [64]. The level of sialo-side incorporation could be controlled by increasing the amount of 6 (Table 15.2). The reactivity of aldehyde 6 toward chitosan was found to be in the range 25-48% due to excessive reduction of the aldehyde under the acidic reaction conditions. Water-soluble materials were only achieved at high DS (DS > 0.53). Sialo-hybrids with lower substitutions were further derivatized with succinic... 

Solid dispersions have been explored as drug delivery systems for over 30 years, initially starting with various forms of polyethylene glycols, citric and succinic acids, and sugars. However, more recent success has been achieved using hydroxypropy-lcellulose (HPC), ethylcellulose (EC), and the commercial forms of methylacrylic acids and their copolymers sold under the name Eudragits. In addition, chitosans have been evaluated for this purpose. 

In 1996, Gauglitz and coworkers coated surfaces with various amino-and carboxy-substituted polymers [198], The polymers tested were branched poly-(ethyleneimine), a,co-amino-functionalized PEG, chitosan, poly(acrylamide-co-acrylic acid) and an amino-modified dextran. The amino-substituted polymers were immobilized on glass by first immobilizing an aminosilane, followed by succinic anhydride/A-hydroxysuccinimide linker chemistry. Poly(acrylamide-co-acrylic acid) was directly coupled to an aminosilanized surface. When probed with 1 mg mL 1 ovalbumin solution, nonspecific adsorption was lowest for the dextran derivative. Notably, nonspecific adsorption increased in most cases when a hydrophobic hapten (atrazine) was coupled to the polymer-modified surface. 

ALP alkaline phosphatase, Cht chitosan, DPM direct polymer melt, HDMECs human dermal microvascular endothelial cells, HUVECs human umbilical vein endothelial cells, MSCs mesenchymal stem cells, nHA nanocrystalline hydroxyapatite, PBS poly(butylene succinate), PCL poly(e-caprolactone), PGA poly (glycolic acid), PLA Poly(lactic acid), PLGA poIy(D,L-lactic-co-glycolic acid), PLCL poly(L-lactide-co-e-caprolactone)... 

Using succinate chitosan form very much improved the reaction selectivity the maximum of selectivity to cis-I,4-butenediol was achieved over catalyst N°2. But in this case, the reaction was not terminated at the stage of 1,4-butenediol formation. The rate of further hydrogenation of 1,4-butenediol (second stage) was rather high. Introducing Pb in chitosan completely suppressed the further 1,4-butenediol hydrogenation. The reaction was spontaneously finished over catalyst N°3 after consumption of 1 mole of Ha. Simultaneously, the selectivity with respect to cis-1,4-butenediol was improved by that chitosan modification. 

To increase the water solubility of chitosan, Toh et al. grafted succinic acid onto chitosan and demonstrated, by measurement of the cloud point, a higher solubility in water at pH 7.3 when 20 mol% of primary amine are converted into carboxylic acid [39]. Moreover, the grafting of carboxylic acids onto chitosan chains improved the transfection efficiency compared to pure chitosan but led to the formation of a weaker complex with DNA. 

Toh EK-W, Chen H-Y et al (2011) Succinated chitosan as a gene carrier for improved chitosan solubility and gene transfection. Nanomedicine 7(2) 174—183... 

Okhamafe, A.O. Amsden, B. Chu, W Goosen, M.F.A. Modulation of protein release from chitosan-alginate microcapsules modified with the pH sensitive polymer-hydroxylpropyl methylcellulose acetate succinate (HPMCAS). J. Microencapsul. 1996, 13 (5), 497-508. 

Lam, P.-L. et al.. Development of hydrocortisone succinic acid/and 5-fluorouracil/chitosan microcapsules for oral and topical drug deliveries. Bioorganic and Medicinal Chemistry Letters, 2012. 22(9) 3213-3218. 

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