Adsorption of zwitterionic drugs onto oxidized cellulose

Zimnitsky, Dmitry S.; Yurkshtovich, T. L.; Bychkovsky, Pavel M.

doi:10.1016/j.jcis.2005.07.058

Cited by 13 publications

(11 citation statements)

References 27 publications

(29 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To assess the reactivity of the pre-treated cellulose, two model reactions were chosen; (1) an acetylation reaction under organic swelling conditions and (2) nitroxyl radical-mediated oxidation (aqueous conditions). These reactions were chosen due to the importance and wide application of these cellulose derivatives (Fischer et al 2008;Jelínková et al 2002;Zimnitsky et al 2006). Acetylation of cellulose has been widely studied in common non-derivatising cellulose solvents (Heinze et al 2003;Jebrane and Sèbe 2007;Jebrane et al 2011;Chen et al 2016).…”

Section: Enhanced Reactivitymentioning

confidence: 99%

Crystallinity reduction and enhancement in the chemical reactivity of cellulose by non-dissolving pre-treatment with tetrabutylphosphonium acetate

et al. 2020

View full text Add to dashboard Cite

Herein, we demonstrate the activation of commercial chemical cellulose pulps towards chemical modification by a pre-treatment step with tetrabutylphosphonium acetate ([P 4444 ][OAc]). A heterogeneous (non-dissolving) pre-treatment was applied allowing for a significant reduction in crystallinity, without concomitant formation of the thermodynamically stable cellulose II. An increase in chemical reactivity was demonstrated using two model reactions; (1) acetylation (organic swelling conditions), where high degrees of substitution (DS) were obtained without the need for a catalyst, and (2) 4-acetamido-TEMPO oxidation (aqueous swelling conditions), where significant degrees of oxidation (DO) were obtained, beyond those for the untreated pulps. In both tests a notable improvement in cellulose reactivity was observed. Regioselectivity of acetylation was assessed using 2D NMR for one low and one high DS sample. The low DS showed a small degree of acetylation of the 6-OH, whereas, the high DS from the pre-treated sample showed mainly mixtures of triacetate and diacetates. Important mechanistic information is attained for future development of aqueous and organic-based reactions involving this ionic liquid pre-treatment.

show abstract

Section: Enhanced Reactivitymentioning

confidence: 99%

Crystallinity reduction and enhancement in the chemical reactivity of cellulose by non-dissolving pre-treatment with tetrabutylphosphonium acetate

et al. 2020

View full text Add to dashboard Cite

show abstract

“…We tested the resistance of isolated bacteria to hydrophilic antibiotics like ampicillin and kanamycin with log P OW (the logarithm of the partition coeffi cient of the antibiotic in octanol water mixture) 1.85 and 7.77, respectively (Aono et al, 1998;Asako et al, 1997;Zimnitsky et al, 2006). The tested antibiotics differ in their mode of action, as well as in their chemical structures and physical properties.…”

Section: Resistance Of Isolated Bacteria To Hydrophilic Antibiotics Amentioning

confidence: 99%

Multidrug resistance in hydrocarbon-tolerant Gram-positive and Gram-negative bacteria

Stancu

Grifoll

2011

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

“…27 Finally, Zimnitsky et al then investigated the adsorption of various amino acids onto carboxymethyl cellulose fibers, showing multilayer adsorption on oxidized cellulose at a high concentration of amino acids in the treatment medium. 28 The thermodynamics of the adsorption of BSA onto CNCs has not yet been reported in the literature and could help to explain some of the apparently conflicting results mentioned above. The dependence of the interactions as a function of the amount of surface functionality has also not yet been described.…”

Section: ■ Introductionmentioning

confidence: 99%

Thermodynamic Study of the Interaction of Bovine Serum Albumin and Amino Acids with Cellulose Nanocrystals

et al. 2017

View full text Add to dashboard Cite

The interaction of bovine serum albumin (BSA) with sulfated, carboxylated, and pyridinium-grafted cellulose nanocrystals (CNCs) was studied as a function of the degree of substitution by determining the adsorption isotherm and by directly measuring the thermodynamics of interaction. The adsorption of BSA onto positively charged pyridinium-grafted cellulose nanocrystals followed Langmuirian adsorption with the maximum amount of adsorbed protein increasing linearly with increasing degree of substitution. The binding mechanism between the positively charged pyridinum-grafted cellulose nanocrystals and BSA was found to be endothermic and based on charge neutralization. A positive entropy of adsorption associated with an increase of the degree of disorder upon addition of BSA compensated for the unfavorable endothermic enthalpy and enabled formation of pyridinium-g-CNC-BSA complexes. The endothermic enthalpy of adsorption was further found to decrease as a function of increasing degree of substitution. Negatively charged cellulose nanocrystals bearing sulfate and/or carboxylic functionalities were found to not interact significantly with the BSA protein. To investigate in more detail the role of single amino acids in the adsorption of proteins onto cellulose nanocrystals, we also studied the interaction of different types of amino acids with CNCs, i.e., charged (lysine, aspartic acid), aromatic (tryptophan, tyrosine), and polar (serine) amino acids. We found that none of the single amino acids bound with CNCs irrespective of surface charge and that therefore the binding of proteins with CNCs appears to require larger amino acid sequences that induce a greater entropic contribution to stabilize binding. Single amino acids are thus not adsorbed onto cellulose nanocrystals.

show abstract

Adsorption of zwitterionic drugs onto oxidized cellulose

Cited by 13 publications

References 27 publications

Crystallinity reduction and enhancement in the chemical reactivity of cellulose by non-dissolving pre-treatment with tetrabutylphosphonium acetate

Crystallinity reduction and enhancement in the chemical reactivity of cellulose by non-dissolving pre-treatment with tetrabutylphosphonium acetate

Multidrug resistance in hydrocarbon-tolerant Gram-positive and Gram-negative bacteria

Thermodynamic Study of the Interaction of Bovine Serum Albumin and Amino Acids with Cellulose Nanocrystals

Contact Info

Product

Resources

About