β‐Cyclodextrin inclusive interaction driven separation of organic compounds

A novel selective separation method for organic compounds, especially thermosensitive substances, has been proposed using unsubstituted β‐cyclodextrin (β‐CD) as a host and some alcohols and aldehydes as model guests in aqueous solution. The separation factors were evaluated from the extraction of an equimolar mixture of alcohol and aldehyde compounds. The inclusion equilibrium constants for several alcohols and aldehydes over β‐CD have been calculated through their UV‐vis spectra. The Gibbs free energy changes of β‐CD/substrates complexes (ΔG) have been calculated combined B3LYP/6‐31G(d)//ONIOM2(B3LYP/6‐31G(d):PM3) with semicontinuum solvation model. The difference of Gibbs free energy changes (ΔΔG) for the inclusion complexes formed via the intermolecular weak interactions e.g., hydrogen bond and electrostatic interaction was the reason why alcohol and aldehyde compounds could be selectively separated. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Chiral separation of mandelic acid by temperature‐induced aqueous two‐phase system

BACKGROUND: R‐mandelic acid is an important chiral pharmaceutical intermediate, which is commonly obtained by biotransformation. This work has focused on using novel chiral recognition technology, aqueous two‐phase extraction, for the chiral separation of mandelic acid. RESULTS: The copper (II) formed a 2:1 complex with β‐CD in an alkaline solution, which was isolated from solution by the addition of ethanol. The complex structure was characterized by IR and UV spectroscopy. The chiral recognition system was established by adding Cu₂‐β‐CD into the triton‐114 aqueous two‐phase extraction system, which preferentially recognizes the (R)‐enantiomer rather than the (S)‐enantiomer. Factors affecting the extraction mechanism were analyzed, namely the concentration of Cu₂‐β‐CD and tritonX‐114, the types of salts, pH, and temperature. It was found that the concentration of Cu₂‐β‐CD and temperature were the most important influencing factors for chiral separation of mandedlic acid. The experimental results showed that the ee values increased with pH and concentration of trition‐114, and the maximum ee was 67.91%. The addition of inorganic salt had a strong influence on ee, which decreased when salt was added into the aqueous two‐phase extraction system. CONCLUSION: A novel chiral recognition technology ‐ aqueous two phase extraction is reported in this paper.The tritonX‐114 aqueous two phase system have a good recognition ability for mandelic acid. Copyright © 2012 Society of Chemical Industry     

Photocatalytic degradation of 2,2‐bis(4‐hydroxy‐3‐methylphenyl) propane (BPP) based on molecular recognition interaction

BACKGROUND: Endocrine disruptors in the aquatic environment and their potential adverse effects are currently issues of concern. One of these endocrine disruptors is 2,2‐bis(4‐hydroxy‐3‐methylphenyl)propane (BPP). In this work the molecular recognition interaction of BPP with β‐cyclodextrin (β‐CD) was studied using IR spectroscopy and steady state fluorescence spectroscopy, and the photocatalytic degradation behaviour of BPP based on molecular recognition interaction was investigated in a TiO₂/UV–visible (λ_max = 365 nm) system. This might provide a new method for the treatment of some organic pollutants in wastewater. RESULTS: β‐CD reacts with BPP to form a 1:1 inclusion complex, the formation constant of which is 4.94 × 10³ L mol^?1. The photodegradation rate constant of BPP after molecular recognition by β‐CD showed a 1.42‐fold increase in the TiO₂/UV–visible (λ_max = 365 nm) system. The photodegradation of BPP depended on the concentration of β‐CD, the pH value, the gaseous medium and the initial concentration of BPP. The photodegradation efficiency of BPP with molecular recognition was higher than that without molecular recognition. After 100 min of irradiation the mineralisation efficiency of BPP after molecular recognition by β‐CD reached 94.8%, whereas the mineralisation efficiency of BPP before molecular recognition by β‐CD was only 40.6%. CONCLUSION: The photocatalytic degradation of BPP after molecular recognition by β‐CD can be enhanced in the TiO₂/UV‐visible (λ_max = 365 nm) system. This enhancement is dependent on the enhancement of the adsorption of BPP, the moderate inclusion depth of BPP in the β‐CD cavity and the increase in the frontier electron density of BPP after molecular recognition. Copyright © 2008 Society of Chemical Industry     

Permanent fixation of β‐cyclodextrin on cotton surface—An assessment between innovative and established approaches

Attachment of β‐cyclodextrin (β‐CD) molecules on cotton textile provides hosting cavities that can include a large variety of guest molecules for specific functionality. Five different new and existing techniques were evaluated for connecting β‐CD and its derivatives to cotton surface. A comparison has been made in terms of maximum attachment of β‐CD on cotton surface. Novel chemical based crosslinking with homo‐bi‐functional reactive dye (C.I. reactive black 5) and grafting with reactive monochlorotriazinyl‐β‐cyclodextrin show maximum attachment to cotton surface. Innovative, enzymatic coupling of especially synthesized 6‐monodeoxy‐6‐mono(N‐tyrosinyl)‐β‐cyclodextrin was performed on cotton textile surface. Enzymatic coupling was also carried out in a homogeneous system and attachment confirmed by UV–vis spectroscopy. This tyrosinase mediated coupling is low temperature and very specific technique. A phenolphthalein based analytical method was partially modified to reliably measure the amount of attached β‐CD on cotton surface. Atomic force microscopy and scanning electron microscopy techniques were used for surface characterization of the treated and untreated cotton surfaces. Alteration in surface topography has been observed for β‐CD treated samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Isothermal crystallization and melting behavior of polypropylene with lanthanum complex of cyclodextrin derivative as a β‐nucleating agent

A novel highly active β‐nucleating agent, β‐cyclodextrin complex with lanthanum (β‐CD‐MAH‐La), was introduced to isotactic polypropylene (iPP). Its influence on isothermal crystallization and melting behavior of iPP was investigated by differential scanning calorimeter (DSC), wide‐angle X‐ray diffraction (WAXD), and polarized light microscopy (PLM). WAXD results demonstrated that β‐CD‐MAH‐La was an effective β‐nucleating agent, with β‐crystal content of iPP being strongly influenced by the content of β‐CD‐MAH‐La and the isothermal crystallization temperature. The isothermal crystallization kinetics of pure iPP and iPP/β‐CD‐MAH‐La was described appropriately by Avrami equation, and results revealed that β‐CD‐MAH‐La promoted heterogeneous nucleation and accelerated the crystallization of iPP. In addition, the equilibrium melting temperature (T) of samples was determined using linear and nonlinear Hoffman‐Weeks procedure. Finally, the Lauritzen‐Hoffman secondary nucleation theory was applied to calculate the nucleation parameter (K_g) and the fold surface energy (σ_e), the value of which verify that the addition of β‐CD‐MAH‐La reduced the creation of new surface for β‐crystal and then led to faster crystallization rate. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Acid hydrolysis of glycosidic bonds in oat β‐glucan and development of a structured kinetic model

Homogeneous acid‐catalyzed hydrolysis of oat β‐glucan, which contains β‐(1,4) and β‐(1,3) glycosidic bonds in a nonrandom order, was studied at 353 K using HCl and H₂SO₄. A new structured kinetic model was developed that takes into account the difference in the reactivity of β‐(1,4) and β‐(1,3) glycosidic bonds as well as their positions in the polysaccharide chain. To minimize the correlation of adjustable parameters in the new model, the reactivities of these bonds were studied independently (T = 313…363 K; c_H+ = 0.1…2 mol/L) using cellobiose and laminaribiose. The difference in kinetic parameters (e.g., T = 338 K: k_β‐(1,4) = 0.693 × 10^?3 L/mol/min, k_β‐(1,3) = 1.027 × 10^?3 L/mol/min) was found to be statistically significant (P < 0.0001), which emphasizes the need for the structured model for oat β‐glucan hydrolysis. The simulation of β‐glucan hydrolysis with the new model was in good agreement with the experimental data and shows improvement over existing nonstructured models. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2570–2580, 2018     

Synthesis of a novel linear water‐soluble β‐cyclodextrin polymer

A novel linear water‐soluble β‐cyclodextrin polymer has been prepared by grafting β‐cyclodextrin on poly[(methyl vinyl ether)‐alt‐(maleic anhydride)]. First, lithium hydride was used to obtain the mono‐alkoxide β‐CD. Grafting of β‐CD derivatives to the polymer backbone was then carried out by an esterification method. Using this method, polymers containing various amounts of β‐CD were synthesized. The resulting grafted polymers were characterized by two complementary methods, ¹H NMR and IR spectroscopy. The first was used to calculate the degree of substitution for the low amounts of β‐CD. The second method was very useful to evaluate the degree of substitution and the molar ratio of CD especially for high amounts of grafting. Our results indicate good agreement between both methods for intermediate rates. Copyright © 2004 Society of Chemical Industry     

Synthesis of a vinyl monomer containing β‐cyclodextrin and grafting onto cotton fiber

To chemically bond β‐cyclodextrin (β‐CD), which can form inclusion complexes, acrylamidomethyl CD (CD–NMA) obtained from the acid‐catalyzed reaction of N‐methylolacrylamide (NMA) and β‐CD was grafted onto cellulose fibers using CeIV as the initiator. The double‐bond content of CD–NMA increased with increase in the NMA/CD mol ratio, and a CD–NMA containing a maximum of three molecules of NMA bonded to a CD molecule could be obtained. Since the grafting condition is acidic, the hydrolytic stability of CD–NMA in aqueous nitric acid was studied. The temperature of hydrolysis proved to have a greater effect on the depletion of double bonds from CD–NMA compared with the concentration of the acid. Thus, CD–NMA was grafted onto cellulose fibers at a low temperature, and FTIR analysis of the CD–NMA‐grafted cotton fibers confirmed the chemical bonding of CD–NMA molecules to cellulose. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 438–446, 2001     

Adsorption and drug release based on β‐cyclodextrin‐grafted hydroxyapatite composite

In this study, β‐cyclodextrin (β‐CD) was covalently grafted on hydroxyapatite (HA) using a coupling agent to improve the drug loading capacity and prolong the drug release. The binding of β‐CD on the HA surface was confirmed by Fourier transformation infrared spectroscopy, thermal gravimetric analysis, and X‐ray powder diffraction. The adsorption capacity of ofloxacin on β‐CD‐grafted hydroxyapatite (β‐CD‐g‐HA) composite was found to be 30 mg g^?1 at 37°C and 24 h. The adsorption process is spontaneous, given the negative values of free energy change. Compared with the release of ofloxacin loaded on HA, the release of ofloxacin loaded on β‐CD‐g‐HA was slowed down 28% and 21% in pH 2.0 and pH 7.4 buffer media at 2 h, respectively. Biocompatibility of β‐CD‐g‐HA was assessed by MTT assay, and the result showed that it had no cytotoxicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Kinetic study on biphasic recognition chiral extraction for separation of α‐cyclohexyl‐mandelic acid enantiomers

BACKGROUND: Chiral solvent extraction is a potentially attractive chiral separation technique. It is essential to know the intrinsic complexation kinetics for selection, design and operation of reactive extraction equipment and for reliable scale‐up. The objective of this research is to study the kinetics of biphasic recognition chiral extraction of α‐cyclohexyl‐mandelic acid (α‐CHMA) enantiomers using a modified Lewis cell. RESULTS: The experimental results demonstrate that the extraction reaction kinetics is fast, and the reactions are first order with respect to α‐CHMA and second order with respect to D‐IBTA, with forward rate constants of 6.54 × 10^?4 mol^?2 m⁶ s^?1 for S‐α‐CHMA and 6.84 × 10^?4 mol^?2 m⁶ s^?1 for R‐α‐CHMA. With increase of HP‐β‐CD concentration in aqueous phase, enantioselectivity increases, while the overall mass transfer coefficients decrease. CONCLUSIONS: Sufficient enantioselectivity and fast kinetics of extraction can be obtained in the BRCE system at HP‐β‐CD concentration of 0.1 mol L^?1 and D‐IBTA concentration of 0.2 mol L^?1. These data will be useful in the design of extraction processes. Copyright © 2012 Society of Chemical Industry     

Preparation and characterization of a novel responsive hydrogel with a β‐cyclodextrin‐based macromonomer

Based on a combination of poly(N‐isopropylacrylamide), which could respond to an external temperature, and β‐cyclodextrin (β‐CD), which could form a molecular inclusion complex, a novel hydrogel, having both thermal and pH sensitivities and containing β‐CD and N‐isopropylacrylamide (NIPA) segments, was synthesized. For the incorporation of β‐CD into the polymer network, a macromonomer was prepared first by the reaction of a β‐CD‐based polymer with maleic anhydride in dimethylformamide and then by copolymerization with NIPA in an aqueous solution. Elemental analysis, IR spectroscopy, differential scanning calorimetry, and swelling measurements were employed for the characterization of the hydrogel chain structure and its physical properties. With methyl orange as a model compound in inclusion tests, it was found that the hydrogel not only possessed a remarkable supramolecular inclusion ability (with respect to that of the small molecule cyclodextrin) but also could sensitively respond to various external stimuli, including the temperature, pH, and ionic strength. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 361–367, 2003     

Synthesis and characterization of grafting β‐cyclodextrin with chitosan

Two new adsorbents [β‐cyclodextrin–chitosan (β‐CD–CTS) and β‐cyclodextrin‐6–chitosan (β‐CD‐6‐CTS)] were synthesized by the reaction of β‐cyclodextrin (β‐CD) with epoxy‐activated chitosan (CTS) and the sulfonation of the C‐6 hydroxyl group of β‐cyclodextrin with CTS, respectively. Their structures were confirmed by IR spectral analysis and X‐ray diffraction analysis, and their apparent amount of grafting was determined by ultraviolet spectroscopy. The adsorption properties of β‐CD‐CTS and β‐CD‐6‐CTS for p‐dihydroxybenzene were studied. The experimental results showed that the two new adsorbents exerted adsorption on the carefully chosen target. The highest saturated capacity of p‐dihydroxybenzene of β‐CD‐CTS and β‐CD‐6‐CTS were 51.68 and 46.41 mg/g, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 860–864, 2004     

Preparation of guar gum bonded with β‐cyclodextrin microspheres and the absorption on basic fuchsine

β‐Cyclodextrin microspheres (β‐CDMs) were prepared and then bonded to guar gum (GG). The structures of the precursor material and product were characterized by X‐ray diffraction and Fourier transform infrared spectroscopy. Phenolphthalein and spectrophotometry were used to determine the content of β‐cyclodextrin (β‐CD) in products. By changing environmental conditions and types of adsorbents, the adsorption capacities of polymers on basic fuchsine were studied. The results indicate that the absorption capacity was decreased accordingly when the pH value was reduced. The increase of temperature had no obvious influence on improving the absorption capacity from 40 to 60°C. When the mass ratio of chloropropyl hydroxyl GG to β‐CDMs to sodium carbonate was 0.6 : 0.8 : 1.0, with the reaction time of 2 h, the best adsorption capacity of 24 mg/g was achieved; this was in accordance with the results of the measurement of the content of β‐CD in the products. The higher content of β‐CDM was beneficial for improving the absorption capacity. By comparing its properties with the absorption capacity of traditional flocculating agents polyacrylamide and polaluminum chloride, the best absorption results for GG bonded with β‐CDMs were obtained. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Optically Pure 1,2‐Bis[(o‐alkylphenyl)phenylphosphino]ethanes and Their Use in Rhodium‐Catalyzed Asymmetric Hydrogenations of α‐(Acylamino)acrylic Derivatives

Optically pure (S,S)‐1,2‐bis[(o‐alkylphenyl)phenylphosphino]ethanes 1a–d were prepared in four steps from phenyldichlorophosphine via phosphine‐boranes as the intermediates. The rhodium complexes 5a–d of these diphosphines were used for the asymmetric hydrogenations of α‐(acylamino)acrylic derivatives including β‐disubstituted derivatives. Markedly high enantioselectivity (78–>99%) was observed for the reduction of β‐monosubstituted derivatives. β‐Disubstituted derivatives were also reduced in considerably high enantioselectivity (up to 90%). The single crystal X‐ray analysis of the rhodium complex 5c of (S,S)‐1,2‐bis[phenyl(5′,6′,7′,8′‐tetrahydronaphthyl)phosphino]ethane ( 1c) revealed its δ‐type structure with face orientation of the two tetrahydronaphthyl groups and edge orientation of the two phenyl groups. This conformation corresponds to that of the rhodium complex of 1,2‐bis[(o‐methoxyphenyl)phenylphosphino]ethane (DIPAMP); the rhodium complex of (R,R)‐DIPAMP, whose chirality at phosphorus is opposite that of 5c , exhibits a λ‐type structure with the face orientation of the two o‐methoxyphenyl groups and the edge orientation of the two phenyl groups. The conformational similarity of these rhodium complexes as well as the stereochemical outcome in the asymmetric hydrogenations means that the coordinative interaction of the methoxy group of DIPAMP with rhodium metal is not the main factor that affects asymmetric induction.     

N‐Alkyl‐, 1‐C‐Alkyl‐, and 5‐C‐Alkyl‐1,5‐dideoxy‐1,5‐imino‐(l)‐ribitols as Galactosidase Inhibitors

A series of 1,5‐dideoxy‐1,5‐imino‐(l )‐ribitol (DIR) derivatives carrying alkyl or functionalized alkyl groups were prepared and investigated as glycosidase inhibitors. These compounds were designed as simplified 4‐epi‐isofagomine (4‐epi‐IFG) mimics and were expected to behave as selective inhibitors of β‐galactosidases. All compounds were indeed found to be highly selective for β‐galactosidases versus α‐glycosidases, as they generally did not inhibit coffee bean α‐galactosidase or other α‐glycosidases. Some compounds were also found to be inhibitors of almond β‐glucosidase. The N‐alkyl DIR derivatives were only modest inhibitors of bovine β‐galactosidase, with IC₅₀ values in the 30–700 μm range. Likewise, imino‐l ‐ribitol substituted at the C1 position was found to be a weak inhibitor of this enzyme. In contrast, alkyl substitution at C5 resulted in enhanced β‐galactosidase inhibitory activity by a factor of up to 1000, with at least six carbon atoms in the alkyl substituent. Remarkably, the ‘pseudo‐anomeric’ configuration in this series does not appear to play a role. Human lysosomal β‐galactosidase from leukocyte lysate was, however, poorly inhibited by all iminoribitol derivatives tested (IC₅₀ values in the 100 μm range), while 4‐epi‐IFG was a good inhibitor of this enzyme. Two compounds were evaluated as pharmacological chaperones for a GM1‐gangliosidosis cell line (R301Q mutation) and were found to enhance the mutant enzyme activity by factors up to 2.7‐fold.     

Preparation and characterization of β‐cyclodextrin‐linked chitosan microparticles

Hydrophobically modified chitosan containing β‐cyclodextrin (CD) units was synthesized by using tosylated β‐CD. The final product was characterized by Fourier transform infrared (FTIR) spectroscopy, elemental analysis and TGA, and rheometry. The polymer bearing β‐CD moieties was used to obtain crosslinked microparticles by spray‐drying which could then be used in a controlled release system for drugs. FTIR confirmed the formation of an amide linkage between cyclodextrin and chitosan. As fluorescence spectroscopy demonstrated, hydrophobic microenvironments were formed by chitosan bearing cyclodextrin in solution at lower concentrations than for chitosan. Rheometry and FTIR showed the crosslinking of the new polymer using genipin, a molecule of natural origin. Microspheres (MS) obtained by spray‐drying showed narrow size distribution when β‐CD was grafted onto chitosan and ξ‐potential of MS was slightly lower although it remained positive. In conclusion, β‐CD linked chitosan polymer can be considered as a very promising controlled drug delivery system for drugs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Adsorption of guanosine,cytidine, and uridine on a β‐cyclodextrin derivative grafted chitosan

A β‐cyclodextrin derivative grafted chitosan (CDD‐C) was synthesized with chitosan and carboxymethyl‐β‐cyclodextrin (β‐CD). Its structure was characterized by elemental, infrared spectra, and X‐ray diffraction analyses. The degree of substitution by the carboxymethyl‐β‐CD moiety achieved 0.27 with the addition of DMF to the reaction solution. The results are in agreement with the expectations. The static adsorption properties for guanosine, cytidine, and uridine were studied. Experimental results demonstrated that CDD‐C had higher adsorption capability for guanosine than cytidine and uridine, and the adsorption capacity for guanosine was 74.20 mg/g. The adsorption capacity was greatly influenced by pH, time, and temperature. The introduction of chitosan enhanced the adsorption ability and adsorption selectivity of β‐CD for guanosine. This novel derivative of chitosan is expected to have wide applications in separation, concentration, and analysis of guanosine, cytidine, and uridine in biological sample. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3050–3055, 2007     

Preparation and sorption studies of β‐cyclodextrin/epichlorohydrin copolymers

β‐Cyclodextrin (β‐CD) copolymer materials were synthesized by reacting different mole ratios (1 : 15, 1 : 25 and 1 : 35) of β‐CD with epichlorohydrin (EP). The products were characterized using N₂ porosimetry, Fourier Transform Infrared spectroscopy, ¹³C CP‐MAS NMR spectroscopy, thermogravimetry analysis, elemental (C and H) analysis, and scanning electron microscopy. The sorption properties in aqueous solution were studied using p‐nitrophenol (PNP) with UV–Vis spectrophotometry. Sorption isotherms were obtained at pH 4.6 and three temperatures (22, 35, and 45°C) and at pH 10.3 at 22°C. The isotherms were analyzed using the BET isotherm model and the sorption parameters provided estimates of the surface area, sorption capacity, and isosteric heats of sorption for each polymeric material. The estimated surface areas are as follows: 58.2, 52.1, and 90.1 m²/g at pH 4.6. At pH 10.3, the estimated surface areas are 44.2, 40.5, and 58.5 m²/g, respectively. The removal efficiency of PNP by the polymeric materials ranged between 4.5 and 58% for the conditions investigated whereas the isosteric heats ranged between ?24.5 and ?13.6 kJ/mol. Removal efficiencies were concluded to strongly depend on the sorption conditions such as pH, temperature, and the relative amounts of sorbent and dye in aqueous solution. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

β‐cyclodextrin‐conjugated hyaluronan hydrogel as a potential drug sustained delivery carrier for wound healing

In order to develop a potential drug sustained delivery carrier suitable for wound healing, a series of β‐cyclodextrin conjugated hyaluronan hydrogels (β‐CD‐HA) with adjustable crosslink densities were synthesized and characterized, meanwhile the delivery kinetics and mechanism of diclofenac as a model anti‐inflammatory drug from these hydrogels were investigated. By controlling the feeding molar ratio of β‐CD/HA, a β‐CD substitution degree of 4.65% was obtained by ¹H‐NMR analysis. The incorporation of β‐CD modification had little effect on the internal porous structure, water swelling ratio, and rheological property of HA hydrogel, which however were influenced by the crosslink density. Although the crosslink density had an influence on the drug loading and release profile by altering the water swelling property, the interaction between β‐CD and drug was the primary factor for the high loading capacity and long‐term sustained delivery of diclofenac. The semiempirical equation fit showed that the release of diclofenac from HA‐based hydrogels followed a pseudo‐Fickian diffusion mechanism. By the aid of β‐CD and controlled crosslink density, a β‐CD‐HA hydrogel with a diclofenac sustained delivery period of over 28 days and desirable physicochemical properties was achieved, which will be a promising drug sustained delivery carrier for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43072.     

Nanoparticles based on β‐conglycinin and chitosan: Self‐assembly,characterization, and drug delivery

The purpose of this study was to fabricate and evaluate nanoparticles based on β‐conglycinin (7S) and chitosan (CS) to deliver 5‐fluorouracil (5‐FU). The nanoparticles were prepared with a self‐assembly method. Turbidity measurements performed at 600 nm were used to investigate the formation of the nanoparticles as a function of the pH, 7S‐to‐CS mass ratio, and total concentration of 7S and CS. The optimum conditions for the preparation of the nanoparticles were a pH of 5.5, a 7S‐to‐CS mass ratio of 4 : 1, and total concentration of 7S and CS of 9 mg/mL. Under these conditions, the nanoparticles in solution had a high turbidity and good stability. Fourier transform infrared spectroscopy revealed that the nanoparticles were formed mainly through electrostatic interactions between the amine groups (? NH₃⁺) of CS and the carboxyl groups (? COO^?) of 7S. Scanning electron microscopy micrographs and dynamic light scattering analysis showed that the nanoparticles had an approximately spherical morphology with a smooth surface, and the mean particle size was about 120 nm with a narrow size distribution. The release of 5‐FU showed an initial burst release followed by a sustained release, and the release was pH‐dependent. The release mechanism of 5‐FU was Fickian diffusion according to the Ritger–Peppas model. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41963.