A novel pH-sensitive hydrogel composed of N,O-carboxymethyl chitosan and alginate cross-linked by genipin for protein drug delivery

Chen, Sung Ching; Wu, Yung Chih; Mi, Fwu Long; Lin, Yu Hsin; Yu, Lin; Sung, Hsing Wen

doi:10.1016/j.jconrel.2004.02.002

Cited by 853 publications

(418 citation statements)

References 36 publications

Supporting

Mentioning

403

Contrasting

Unclassified

Order By: Relevance

“…The asymmetric and symmetric stretching of carboxyl anions were observed at 1604 cm -1 and 1412 cm -1 , respectively, while absorption band of the bending of the secondary amide of chitosan was observed at 1653 cm -1 . For chitosan, stretching vibrations of C-O at 1066, 1026, and 895 cm -1 indicated the presence of secondary (-CH-OH) and primary (-CH 2 -OH) hydroxyl groups, and cyclic ether bond (C-O-C), respectively (Chen et al, 2004).…”

Section: Fourier Transform Infrared Spectroscopymentioning

confidence: 99%

Encapsulation of Anthocyanins from Black Rice (Oryza Sativa L.) Bran Extract using Chitosan-Alginate Nanoparticles

Bulatao¹,

Samin²,

Salazar³

et al. 2017

JFR

View full text Add to dashboard Cite

This study was conducted to extract and encapsulate anthocyanins from black rice bran using chitosan-alginate nanoparticles. Ten black rice varieties were screened for the anthocyanin content and the variety with the highest anthocyanins was used for the encapsulation. The anthocyanins were extracted by defatting the bran with n-hexane and soaking it with 85% acidified ethanol. The crude anthocyanin extract (CAE) was freeze-dried at -110°C for 48 h and then encapsulated in chitosan-alginate nanoparticles using two processes: ionic pre-gelation and polyelectrolyte complex formation. The mass ratio of chitosan and alginate polymers used in this study was 100:10. The treatments applied were as follows: T 0 -0 mg CAE, T 1 -10 mg CAE, T 2 -20 mg CAE, and T 3 -30 mg CAE. The resulting capsules were characterized in terms of chemical properties, surface morphology, particle size, polydispersive index, encapsulation efficiency, and 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity. Screening of rice samples indicated that Ominio bran had the highest anthocyanin content (36.11 mg/g). Anthocyanins were successfully encapsulated in the matrix as shown by the Scanning Electron Microscopy images and Fourier Transform Infrared spectra of the anthocyanin-loaded chitosan-alginate nanoparticles. Among the different concentrations of CAE, T 3 had the highest encapsulation efficiency (68.9%) and antioxidant scavenging activity (38.3%) while T 1 and T 2 had the lowest. Ascending particle size was observed for T 0 (358.5 nm), T 3 (467.9 nm), T 1 (572.3 nm), and T 2 (635.9 nm). All anthocyanin-loaded capsules were found to be of nano-size (<1000 nm). The study concluded that chitosan-alginate nanoparticles can be a good encapsulating material for anthocyanin.

show abstract

Section: Fourier Transform Infrared Spectroscopymentioning

confidence: 99%

Encapsulation of Anthocyanins from Black Rice (Oryza Sativa L.) Bran Extract using Chitosan-Alginate Nanoparticles

Bulatao¹,

Samin²,

Salazar³

et al. 2017

JFR

View full text Add to dashboard Cite

show abstract

“…The volume change, and hence the degree of swelling of these hydrogels, with acidic or alkaline functionalities would depend on the degree of ionization of the functional groups. Poly(acrylic acid) [113,114], poly(methacrylic acid) [115][116][117], poly(ethylene imine) [118], poly(propylene imine) [119], chitosan [120][121][122][123], poly(L-lysine) [124,125], and poly (L-histidine) [126][127][128][129] are typical examples of pH sensitive polymeric hydrogels.…”

Section: Ph-sensitive Gelsmentioning

confidence: 99%

“…For example, the stability of a PEC formed using chitosan and alginate would depend on the ionization of the carboxylate groups of the alginate macromer and of the amino groups of the chitosan macromer, forming the PEC [146][147][148][149][150]. Since alginate-chitosan matrices exhibit pH-dependent swelling, the reversible ionization/deionization of the amino groups in chitosan and the carboxylate groups of alginate would essentially determine the stability of the PEC structure.…”

Section: Ph-sensitive Gelsmentioning

confidence: 99%

Smart polymeric gels: Redefining the limits of biomedical devices

Chaterji

Kwon

Park

2007

Progress in Polymer Science

560

364

View full text Add to dashboard Cite

This review describes recent progresses in the development and applications of smart polymeric gels, especially in the context of biomedical devices. The review has been organized into three separate sections: defining the basis of smart properties in polymeric gels; describing representative stimuli to which these gels respond; and illustrating a sample application area, namely, microfluidics. One of the major limitations in the use of hydrogels in stimuli-responsive applications is the diffusion rate limited transduction of signals. This can be obviated by engineering interconnected pores in the polymer structure to form capillary networks in the matrix and by downscaling the size of hydrogels to significantly decrease diffusion paths. Reducing the lag time in the induction of smart responses can be highly useful in biomedical devices, such as sensors and actuators. This review also describes molecular imprinting techniques to fabricate hydrogels for specific molecular recognition of target analytes. Additionally, it describes the significant advances in bottom-up nanofabrication strategies, involving supramolecular chemistry. Learning to assemble supramolecular structures from nature has led to the rapid prototyping of functional supramolecular devices. In essence, the barriers in the current performance potential of biomedical devices can be lowered or removed by the rapid convergence of interdisciplinary technologies.

show abstract

“…Carboxymethyl derivatives of chitosan (CMC) were found to be nontoxic, anionic, and water soluble. Because of these excellent properties, CMC found applications in biomedical and environmental fields [14,[92][93][94][95]. Depending on the position of the carboxymethyl substitution, these derivatives can be classified as O-CMC, N-CMC, and N,O-CMC [14,93].…”

Section: 1 Carboxymethylationmentioning

confidence: 99%