Synthesis and rheological properties of hydrogels based on amphiphilic alginate-amide derivatives

Vallée, Frédéric; Muller, Christophe; Durand, Alain; Schimchowitsch, Sarah; Dellacherie, Édith; Kelche, Christian; Cassel, J.C.; Léonard, Michèle

doi:10.1016/j.carres.2008.10.029

Cited by 95 publications

(38 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results could be explained by the facts that the amidation of SA could enhance its affinity to the hydrophobic drug and facilitate the formation of the drug-loaded nanocapsules, which was significant for the sustained release of kcyhalothrin. Meanwhile, the amidation modification of alginate is widely used in biomedical application and tissue engineering as a result of its biocompatibility and nontoxicity for humans [33,34]. Thus, the electrospun AAD/PVA blend nanofibers were good candidates for use in biomedical applications due to their drug-loading and sustained release properties.…”

Section: Release Studiesmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of amphiphilic alginate derivatives and electrospinning blend nanofibers: a novel hydrophobic drug carrier

et al. 2015

View full text Add to dashboard Cite

As a kind of novel hydrophobic drug carrier materials, the drug-loaded nanofibers were successfully fabricated using amphiphilic alginate derivative (AAD) and poly (vinyl alcohol) (PVA) by electrospinning method. The AAD was synthesized by amide linkage attachment of octylamine onto the carboxylic group of alginate, which was characterized by the means of elemental analysis, FT-IR spectrometer, 1 H NMR spectrometer and fluorescence measurement. Experimental results showed the amidation of alginate was successful, in which the degree of modification was 0.27 and the critical aggregation concentration in 0.15 mol/L aqueous NaCl solution was 0.43 mg/mL. The octyl groups of AAD could effectively make alginate chains flexible and enhance chain entanglements through the hydrophobic interactions between octyl groups. In contrast to sodium alginate (SA)/ PVA blend solutions, AAD/PVA blend solutions showed more excellent electrospinnability. Additionally, the different volume ratios of SA or AAD to PVA played an important role in the formation and morphology of the electrospun blend nanofibers. Although the amidation of alginate could not fundamentally alter the spinnability of alginate, the content of alginate in the blend nanofibers was appropriately increased. The new generated drug-loaded AAD/PVA (20/80) blend nanofibers exhibited relatively continuous and uniform nanofibers with the average diameter of 191.72 nm. Compared to the drug-loaded SA/PVA (20/80) blend nanofibers, the drug-loaded AAD/PVA (20/80) blend nanofibers presented a sustained release performance with the slow release of about 76 % k-cyhalothrin during the initial period of 10 h.

show abstract

Section: Release Studiesmentioning

confidence: 99%

“…Amphiphilic alginate derivative (AAD) was synthesized by the amidation through alginate coupling with octylamine in the presence of EDCÁHCl [23,[33][34][35]. The amidation reaction was carried out through the following steps.…”

Section: Synthesis and Characterization Of Aadmentioning

confidence: 99%

Synthesis of amphiphilic alginate derivatives and electrospinning blend nanofibers: a novel hydrophobic drug carrier

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The rheological characterization of a material generally comprises both studies in the flow and oscillatory modes (Vallée et al 2009). In the flow Fig.…”

Section: Viscosity and Rheological Propertiesmentioning

confidence: 99%

Extracted and depolymerized alginates from brown algae Sargassum vulgare of Lebanese origin: chemical, rheological, and antioxidant properties

et al. 2015

View full text Add to dashboard Cite

International audiencePurified sodium alginate (PS alginate) was isolated from the brown seaweed Sargassum vulgare collected from the Lebanese Mediterranean coast and then depolymerized into homopolymeric polyguluronate (PolyG) and polymannuronate (PolyM) blocks by controlled acid hydrolysis. These fractions of PS alginate issued from S. vulgare were characterized in terms of composition and structure by SEC, elemental analysis, FTIR and 1H and 13C NMR spectroscopy. An alginate with a low content of protein (\textless0.62 %) and a molecular weight of 110 200 g mol-1 was identified as sole polysaccharide. Depolymerized PS alginate fractions, PolyG (32.6 %) and PolyM (22.3 %), were found to have close molecular weights, of 7500 and 6900 g mol-1, respectively. From NMR analysis, values of F G, F M, M/G ratio, F GG, F MM, and F GM (or F MG) blocks were determined and compared with those of alginates from S. vulgare of Brazilian origin and other Sargassum species. Our PS alginate appeared different from the Brazilian S. vulgare alginate, with a lower M/G ratio (0.785 instead of 1.27), a predominance of the G blocks (F G and F GG \textgreater 0.5) instead of the M blocks, and it showed more similarity to the composition of some alginates extracted from other species of Sargassum. High G or M contents (≥80 %) were measured from PolyG and PolyM blocks, respectively. The viscosity of the PS alginate and its fractions PolyG and PolyM was determined. PS alginate from S. vulgare of Lebanese origin showed a Newtonian flow behavior for concentration lower than 0.5 % in 0.1 M NaCl solution, while a shear-thinning pseudoplastic behavior is observed for concentration range between 0.75 and 10 %. Also, storage (G′) and loss (G″) moduli were studied for two concentrations of PS alginate solutions (5 and 10 %). Antioxidant properties of the non-depolymerized and depolymerized alginates were evaluated by determining the scavenging ability of the stable radical DPPH (2,2-diphenyl-1 picrylhydrazyl). Clearly, the results demonstrated differences in radical scavenging efficacy between PolyG and PolyM fractions. The higher hydroxyl radical scavenging activity was observed for the PolyG fractions (~92 % at 2 mg mL-1) and this activity was comparable with those of standard antioxidants. These PolyG fractions could be valuable in foods or pharmaceutical products as alternatives to synthetic antioxidant

show abstract

“…The formed aggregates are more stable for the purpose of drug release modulation and more compact in aqueous sodium chloride solution than parent sodium alginate, following intermolecular hydrophobic interaction between cholesteryl grafts. Alginate-amide derivative [126] Covalent attachment of dodecylamine onto alginate chains via amide linkage reduces the progressive loss of associative behaviour encountered by dodecyl ester alginate due to hydrolysis of ester bond. The formed hydrogel is expected to be more stable mechanically over long-term storage and exhibits sustained drug release property.…”

Section: Graft Copolymer Physicochemical and Drug Release Propertiesmentioning

confidence: 99%

Alginate graft copolymers and alginate–co-excipient physical mixture in oral drug delivery

Wong

2011

Journal of Pharmacy and Pharmacology

View full text Add to dashboard Cite

Objectives Use of alginate graft copolymers in oral drug delivery reduces dosage form manufacture complexity with reference to mixing or coating processes. It is deemed to give constant or approximately steady weight ratio of alginate to covalently attached co-excipient in copolymers, thereby leading to controllable matrix processing and drug release. This review describes various grafting approaches and their outcome on oral drug release behaviour of alginate graft copolymeric matrices. It examines drug release modulation mechanism of alginate graft copolymers against that of co-excipients in non-grafted formulations. Key findings Drug release from alginate matrices can be modulated through using either co-excipients or graft copolymers via changing their swelling, erosion, hydrophobicity/ hydrophilicity, porosity and/or drug adsorption capacity. However, it is not known if the drug delivery performance of formulations prepared using alginate graft copolymers is superior to those incorporating graft-equivalent co-excipient physically in a dosage form without grafting but at the corresponding graft weight, owing to limited studies being available. Conclusions The value of alginate graft copolymers as the potential alternative to alginate-co-excipient physical mixture in oral drug delivery cannot be entirely defined by past and present research. Such an issue is complicated by the lack of green chemistry graft copolymer synthesis approach, high grafting process cost, complications and hazards, and the formed graft copolymers having unknown toxicity. Future research will need to address these matters to achieve a widespread commercialization and industrial application of alginate graft copolymers in oral drug delivery

show abstract

Synthesis and rheological properties of hydrogels based on amphiphilic alginate-amide derivatives

Cited by 95 publications

References 28 publications

Synthesis of amphiphilic alginate derivatives and electrospinning blend nanofibers: a novel hydrophobic drug carrier

Synthesis of amphiphilic alginate derivatives and electrospinning blend nanofibers: a novel hydrophobic drug carrier

Extracted and depolymerized alginates from brown algae Sargassum vulgare of Lebanese origin: chemical, rheological, and antioxidant properties

Alginate graft copolymers and alginate–co-excipient physical mixture in oral drug delivery

Contact Info

Product

Resources

About