Physically crosslinked alginate/N,O-carboxymethyl chitosan hydrogels with calcium for oral delivery of protein drugs

Lin, Yu Hsin; Liang, Hsiang Fa; Chung, Ching-Kuang; Chen, Mei-Chin; Sung, Hsing‐Wen

doi:10.1016/j.biomaterials.2004.06.011

Cited by 402 publications

(201 citation statements)

References 25 publications

Supporting

Mentioning

193

Contrasting

Unclassified

Order By: Relevance

“…1 However, oral administration of protein drugs also has certain obstacles, as drugs must overcome various significant barriers in the gastrointestinal (GI) tract prior to delivery to the bloodstream. 2,3 First of all, protein drugs are readily degraded by the low pH of gastric medium in the stomach.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of Nanoparticles Shelled with Chitosan for Oral Insulin Delivery

et al. 2006

Self Cite

View full text Add to dashboard Cite

Nanoparticles (NPs) composed of chitosan (CS) and poly(γ-glutamic acid) (γ-PGA) were prepared by a simple ionic-gelation method for oral insulin delivery. Fourier transform infrared (FT-IR) spectra indicated that CS and γ-PGA were ionized at pH 2.5-6.6, while X-ray diffractograms demonstrated that the crystal structure of CS was disrupted after it was combined with γ-PGA. The diameters of the prepared NPs were in the range of 110-150 nm with a negative or positive surface charge, depending on the relative concentrations of CS to γ-PGA used. The NPs with a positive surface charge (or shelled with CS) could transiently open the tight junctions between Caco-2 cells and thus increased the paracellular permeability. After loading of insulin, the NPs remained spherical and the insulin release profiles were significantly affected by their stability in distinct pH environments. The in vivo results clearly indicated that the insulin-loaded NPs could effectively reduce the blood glucose level in a diabetic rat model.

show abstract

Section: Introductionmentioning

confidence: 99%

Preparation and Characterization of Nanoparticles Shelled with Chitosan for Oral Insulin Delivery

et al. 2006

Self Cite

View full text Add to dashboard Cite

show abstract

“…[8][9][10][11] The use of chitosan has been repeated in the literature is either for coating alginate beads in order to alter the diffusion rate of the encapsulated substances 12) or as an additive for the bulk modification of the beads structure. 13,14) Nateglinide is an antidiabetic drug used for the treatment of Type-II diabetes mellitus and has a short half-life of 1.5 h, and the usual oral dosage regimen is 60-240 mg taken 3 times a day. Thus Nateglinide is a suitable candidate for oral sustained release drug delivery.…”

mentioning

confidence: 99%

Studies in the Development of Nateglinide Loaded Calcium Alginate and Chitosan Coated Calcium Alginate Beads

Basu

Rajendran

2008

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

The drug delivery systems using biodegradable natural polymeric particles are becoming a clinical reality with many benefits for the patient. The versatility of polymeric materials allows the fabrication of the delivery device with desirable degree of swelling, and drug release. Alginate is a natural biopolymer which forms a hydrogel in the presence of divalent cations like Ca 2ϩ . 1,2) The inert environment within the biopolymer network of alginates allows for the entrapment of a wide range of bioactive substances, cells and drug molecules, with minor interactions between them.3)The use of calcium-alginate beads in controlled drug delivery technology for the gastro-intestinal administration of proteins 4) and other drug molecules 5-7) are well known. Much attention has been received in recent years regarding the use of chitosan-alginate polyelectrolyte complex in controlled drug delivery. [8][9][10][11] The use of chitosan has been repeated in the literature is either for coating alginate beads in order to alter the diffusion rate of the encapsulated substances 12) or as an additive for the bulk modification of the beads structure. 13,14) Nateglinide is an antidiabetic drug used for the treatment of Type-II diabetes mellitus and has a short half-life of 1.5 h, and the usual oral dosage regimen is 60-240 mg taken 3 times a day. Thus Nateglinide is a suitable candidate for oral sustained release drug delivery. Keeping these in view, the present study has been undertaken. The investigation was phased out in the following manner. Firstly the effect of calcium ion and chitosan in the coagulation fluid on drug release characteristics and its mechanism was considered. Then the physical state of the drug in the beads and the swelling behavior of the bead formulations were undertaken. ExperimentalMaterials The following materials were obtained from the indicated suppliers and used as received: sodium alginate (low viscosity; viscosity of 2% solution 25°C, Ϸ250 cps from SNAP Natural and alginate products limited, Ranipet, India), chitosan (85% degree of deacetylation, molecular weight more than 10 3 kDa from India sea foods, Cochin, India). Calcium chloride dihydrate (Qualigens, Mumbai, India), di-sodium hydrogen phosphate anhydrous, potassium di-hydrogen phosphate, sodium acetate, potassium chloride, sodium hydroxide, dichloromethane, ethanol (99%), hydrochloric acid and acetic acid glacial (Merck, Mumbai, India). Nateglinide was of pharmaceutical grade (Alembic chemical works Ltd., Vadodara, India). Preparation of Nateglinide Loaded Calcium Alginate Beads (CAB)In this method the Nateglinide loaded calcium alginate beads were prepared using varying concentration of calcium chloride in the gelation medium [2% (w/v), 5% (w/v)] while maintaining the drug : polymer ratio as 1 : 3 and 1 : 4 separately for varying concentration of calcium chloride on each occasion. Required amount of Nateglinide dissolved in dichloromethane was slowly dispersed in sodium alginate solution with constant stirring for 3 h, maintaining the drug :...

show abstract

“…Hydrogels are classi ed as physically or chemically crosslinked gels with regard to the type of crosslinking. In physically crosslinked gels, polymer networks are formed via physical interactions between macromolecular chains, such as van der Waals forces, ionic interactions, hydrogen bonds or hydrophobic interactions [9,[35][36][37]. Physically crosslinked hydrogels can be strongly or weakly crosslinked [38].…”

Section: Type Of Crosslinkingmentioning

confidence: 99%

Stimuli-responsive Hydrogels for Textile Functionalisation: A Review

Štular¹,

Simončić²,

Tomšič³

2017

TEK

View full text Add to dashboard Cite

This article reviews hydrogels used for the functionalisation of textile materials. Hydrogels are reviewed according to their reason for incorporation, aspects of crosslinking, stimuli-responsive characteristics and particle size. A more in-depth focus on the eff ect of hydrogel particle size is provided, where macrogels, microgels and nanogels for textile functionalisation are considered. The advantages and disadvantages of each size group are presented. Furthermore, the correlation between synthesis conditions and the sizes of hydrogel particles is discussed, in addition to the applications of macro-, micro-and nanogels to textile materials and their intended uses. Keywords: smart textiles, stimuli-responsive hydrogels, microgels, nanogels, preparation methods Izvleček

show abstract

Physically crosslinked alginate/N,O-carboxymethyl chitosan hydrogels with calcium for oral delivery of protein drugs

Cited by 402 publications

References 25 publications

Preparation and Characterization of Nanoparticles Shelled with Chitosan for Oral Insulin Delivery

Preparation and Characterization of Nanoparticles Shelled with Chitosan for Oral Insulin Delivery

Studies in the Development of Nateglinide Loaded Calcium Alginate and Chitosan Coated Calcium Alginate Beads

Stimuli-responsive Hydrogels for Textile Functionalisation: A Review

Contact Info

Product

Resources

About