In Situ Preparation of Nanocrystalline γ-Fe<sub>2</sub>O<sub>3</sub> in Iron(II) Cross-Linked Alginate Gels

Kroll, E.; Winnik, Françoise M.; Ziolo, Ronald F.

doi:10.1021/cm960095x

Cited by 168 publications

(105 citation statements)

References 12 publications

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“…Although the saturation magnetization (M s ) of Fe 3 O 4 was 70.83 emu/g, which is higher than those of H1, H2, the magnetizations of the hydrogels are high enough for biomedical application. In addition, the M r /M s values of H1 and H2 are significantly lower than T30 and the previous studies [8,9]. In the limit of the authors' knowledge, this is the lowest M r /M s has been reported.…”

Section: Magnetization Propertiescontrasting

confidence: 70%

“…It is also observed that the very small particles (the circles in Figure 4) appeared which may be the results of iron oxide nanoparticle trapped inside the alginate matrix. Compared with the previous reports, the size of H1, H2 are of equivalent to the smallest sizes of MNPs [5,8,9]. The decrease of MNP size can be attributed to the limit of the crystal growth since the Fe (II) and Fe (III) ions are trapped inside the hydrogel matrix.…”

Section: Crystal Structure Of Materials Characterized By Xrd and Tem mentioning

confidence: 70%

“…In detail, the particle size is smaller than 5.5 nm, MNP can be quickly removed through the renal system [7]. However, only several reports successfully synthesized MNP at this size [5,8,9]. Therefore, we studied the synthesis of iron nanoparticle which was trapped in alginate hydrogel matrix to reduce the size of iron nanoparticle and subsequently produce the magnetic hydrogel.…”

Section: Introductionmentioning

confidence: 99%

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Preparation of Magnetic Hydrogel by in-Situ Coprecipitation Process

Nguyen¹

2018

JST

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This study describes a preparation of magnetite nanoparticle by co-precipitation of Fe(II) and Fe(III) in alginate hydrogel matrix. This simple process is sufficient for producing a superparamagnetic, well dispersible magnetite nanoparticle in polymer hydrogel matrix. Two approaches for iron ions loadings are induced. The first approach includes two steps, the hydrogel beads are formed before the iron ions are being diffused into the hydrogel matrix. The second approach is the simultaneous forming of hydrogel containing iron ions. The ions loaded hydrogel is then coprecipitated in the presence of ammonium hydroxide to afford iron oxide magnetite nanoparticles in alginate hydrogel matrix. The composition and characteristics of the hydrogel containing magnetite nanoparticle were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). The results showed that the particles size of magnetic nanoparticles prepared by in-situ coprecipitation method is around ~ 6 nm and smaller than that produced by normal coprecipitation method. The magnetic hydrogel exhibits superparamagnetic properties with the saturation magnetization of about 25 emu/g, the ratio of Mr/Ms about 0.8 ×10 -3 . Possessing the biocompatibility as well as superparamagnetism, the magnetite hydrogel is a promising materials for environmental and biomedical applications.

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Section: Magnetization Propertiescontrasting

confidence: 70%

Section: Crystal Structure Of Materials Characterized By Xrd and Tem mentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

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Preparation of Magnetic Hydrogel by in-Situ Coprecipitation Process

Nguyen¹

2018

JST

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“…and trivalent cation like Al 3+ , due to an ionic interaction between the carboxylic acid groups located on the polymer backbone and these cations (17,18). Alginates have mucoadhesive property, but the cross-linked alginates are usually fragile (19,20). Therefore, to formulate various crosslinked alginate mucoadhesive microcapsules for controlled drug delivery, blending with mucoadhesive polymers is one of the most popular approaches.…”

Section: Introductionmentioning

confidence: 99%

Development, Optimization, and Anti-diabetic Activity of Gliclazide-Loaded Alginate–Methyl Cellulose Mucoadhesive Microcapsules

Pal

Nayak²

2011

AAPS PharmSciTech

118

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Abstract. The purpose of this work was to develop and optimize gliclazide-loaded alginate-methyl cellulose mucoadhesive microcapsules by ionotropic gelation using central composite design. The effect of formulation parameters like polymer blend ratio and cross-linker (CaCl 2 ) concentration on properties of gliclazide-loaded alginate-methyl cellulose microcapsules like drug encapsulation efficiency and drug release were optimized. The optimized microcapsules were subjected to swelling, mucoadhesive, and in vivo studies. The observed responses coincided well with the predicted values from the optimization technique. The optimized microcapsules showed high drug encapsulation efficiency (83.57±2.59% to 85.52±3.07%) with low T 50% (time for 50% drug release, 5.68±0.09 to 5.83±0.11 h). The in vitro drug release pattern from optimized microcapsules was found to be controlled-release pattern (zero order) with case II transport release mechanism. Particle sizes of these optimized microcapsules were 0.767± 0.085 to 0.937±0.086 mm. These microcapsules also exhibited good mucoadhesive properties. The in vivo studies on alloxan-induced diabetic rats indicated the significant hypoglycemic effect that was observed 12 h after oral administration of optimized mucoadhesive microcapsules. The developed and optimized alginate-methyl cellulose microcapsules are suitable for prolonged systemic absorption of gliclazide to maintain lower blood glucose level and improved patient compliance.

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“…These residues are arranged in homopolymeric blocks (GG and MM) and heteropolymeric blocks (MG) (Smidsrod & Draget, 1996 (Davis et al, 2003;Shilpa et al, 2003). Though alginates have mucoadhesive property, but, the cross-linked alginate beads are usually fragile (Kroll et al, 1996;Llanes et al, 2000). Therefore, to formulate various cross-linked alginate mucoadhesive microspheres, blending of different mucoadhesive polymers is one of the most popular approaches in this endeavor.…”

Section: Original Articlesmentioning

confidence: 99%

Novel tamarind seed polysaccharide-alginate mucoadhesive microspheres for oral gliclazide delivery:in vitro–in vivoevaluation

Pal¹,

Nayak²

2012

Drug Delivery

143

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Novel tamarind seed polysaccharide (TSP)-alginate mucoadhesive microspheres were prepared using TSP and alginate as blend in different ratios with different calcium chloride (CaCl 2 ) concentration as a cross linker by ionotropic gelation. The prepared microspheres were of spherical shape having rough surfaces, and average particle sizes within the range of 752.12 ± 6.42 to 948.49 ± 20.92 µm. The drug entrapment efficiency of these microspheres were within the range between 58.12 ± 2.42 to 82.78 ± 3.43% w/w. Fourier transform infrared (FTIR) studies indicated that there were no reactions between gliclazide, and polymers (TSP, and sodium alginate) used. Different formulations of gliclazide loaded TSP-alginate microspheres showed prolonged in vitro release profiles of gliclazide over 12 hours in both stomach pH (pH 1.2), and intestinal pH (pH 7.4). It was found that the gliclazide release in gastric pH was comparatively slow and sustained than intestinal pH. These TSP-alginate microspheres also exhibited good mucoadhesivity. The in vivo studies on alloxan-induced diabetic rats (Animal Ethical Committee registration number: IFTM/837ac/0160) demonstrated the significant hypoglycemic effect of selected formulation of TSP-alginate mucoadhesive microspheres containing gliclazide on oral administration. This developed gliclazide loaded new TSPalginate mucoadhesive microspheres may be very much useful for prolonged systemic absorption of gliclazide for proper maintaining blood glucose level and advanced patient compliance.

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In Situ Preparation of Nanocrystalline γ-Fe₂O₃ in Iron(II) Cross-Linked Alginate Gels

Cited by 168 publications

References 12 publications

Preparation of Magnetic Hydrogel by in-Situ Coprecipitation Process

Preparation of Magnetic Hydrogel by in-Situ Coprecipitation Process

Development, Optimization, and Anti-diabetic Activity of Gliclazide-Loaded Alginate–Methyl Cellulose Mucoadhesive Microcapsules

Novel tamarind seed polysaccharide-alginate mucoadhesive microspheres for oral gliclazide delivery:in vitro–in vivoevaluation

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In Situ Preparation of Nanocrystalline γ-Fe2O3 in Iron(II) Cross-Linked Alginate Gels

Cited by 168 publications

References 12 publications

Preparation of Magnetic Hydrogel by in-Situ Coprecipitation Process

Preparation of Magnetic Hydrogel by in-Situ Coprecipitation Process

Development, Optimization, and Anti-diabetic Activity of Gliclazide-Loaded Alginate–Methyl Cellulose Mucoadhesive Microcapsules

Novel tamarind seed polysaccharide-alginate mucoadhesive microspheres for oral gliclazide delivery:in vitro–in vivoevaluation

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In Situ Preparation of Nanocrystalline γ-Fe₂O₃ in Iron(II) Cross-Linked Alginate Gels