Hydrophobic modification of sodium alginate and its application in drug controlled release

Abstract

Sodium alginate was hydrophobically modified by coupling of polybutyl methacrylate onto the alginate. The polybutyl methacrylate was previously prepared through polymerization of butyl methacrylate in the presence of 2-amino-ethanethiol as a chain transfer agent. The structure of the product was characterized by Fourier-transformed infrared spectrometry, nuclear magnetic resonance ((1)HNMR) and thermogravimetry. The result of fluorescence analysis showed that the hydrophobicity of the modified alginate was obviously increased. The modified alginate conjugate was used for immobilization of bovine serum albumin in the presence of calcium chloride. In addition, the release behavior of the drug-loaded alginate in deionized water and Tris-HCl buffer solution (pH 7.2) was investigated. It was found that the modified sodium alginate possessed prolonged release behavior compared to unmodified sodium alginate, and it had potential application in controlled release as a drug carrier.

A pH-sensitive composite hydrogel based on sodium alginate and medical stone: Synthesis, swelling, and heavy metal ions adsorption properties

“…The successive weight loss about 8.2 wt% (219~318 ºC) for MS0 and about 8.1 wt% (215~337 ºC) for MS10 can be attributed to the lactonization or transglucosidation of NaAlg. 33 The successive weight loss about 14.4 wt% (3184 29 ºC) for MS0 and about 13.5 wt% (337~435 ºC) for MS10 can be attributed to the breaking of C-O-C bonds in NaAlg chains and the formation of anhydride with the elimination of water molecule derived from the two neighboring carboxylic groups of the grafted PNaA chains. 34 The weight losses about 24.5 wt% between 429 and 485 ºC for MS0 and about 21.1 wt% between 435 and 489 ºC for MS10 are due to the breakage of main-chain scission and the destruction of crosslinked network structure.…”

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

“…[1,11,[13][14][15] It induces several biological effects such as anti-cholesterolaemic, [2,[16][17][18][19][20][21][22] antihypertensive, [23][24][25] antidiabetic, [2,17,19,26] anti-obesity, [17] antimicrobial, [25,27] anti-cancer, [2,28] anti-hepatotoxicity, [2] wound healing, [29,30] anticoagulation and coagulation [2] activity. The biological effects of alginate are related to its structural assembly and physicochemical attributes.…”

“…The hydrogel made of graft copolymer expresses a lower swelling capacity due to collapse of N-isopropylacrylamide at specific temperature range thereby sustaining drug release. Alginate-g-poly(butyl methacrylate), a-methyl methacrylate-gsodium alginate [15,121] The microspheres formed from alginate conjugate can prolong drug release when compared to microspheres made of unmodified alginate. The alginate conjugate is more hydrophobic than the parent polymer.…”

“…One example is grafting of vinyl monomers onto alginate using catalysts, such as ceric (IV) ions, persulfate and hydrogen peroxide, causes alginate ring opening. [15] 3. Product instability -alginate graft copolymer, such as thiolated copolymer, turns brownish rapidly upon exposing to air.…”

Synthesis of polyglycolic acid grafting from sodium alginate through direct polycondensation and its application as drug carrier

“…However, Alg has some weak points, including strong hydrophilicity, poor mechanical strength, low level of drug loading, and burst release, resulting in poor utilization of the drug. Therefore, the hydrophobic modification of Alg is an interesting and challenging work [6][7][8][9]. For example, Dellacherie et al [10] synthesized amphiphilic derivatives with tetrabutylammonium alginate and alkyl halide in homogeneous medium (dimethylsulfoxide, DMSO).…”