A new hydrogel drug delivery system based on Hydroxyethylstarch derivatives

Harling, Steffen; Schwoerer, A.; Scheibe, Kristin; Daniels, Rolf; Menzel, Henning

doi:10.3109/02652040903367301

Cited by 21 publications

(24 citation statements)

References 17 publications

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“…Initial fast release was probably due to release of drug stored in hydrogel pores or due to release of drug molecules closer to the surface, while slower release in second phase occurred by diffusion of drug molecules through the polymer network. 4,21 This phenomenon of fast release followed by a slow release of encapsulated drug is also reported by other researchers for the same or different drugs. 4,28,29 It was already discussed during the study related to the study of average molecular weight between crosslinks ( ) that decreases as DS increases (Figure 4).…”

mentioning

confidence: 51%

“…The presence of imidazole groups in route 2 comparative to unreacted hydroxylethyl (and hydroxyl) groups in route 1 may be the possible reason regarding the decreased solubility of resulting HESHEMA synthesized by route 2. Harling et al and Schwoerer et al 4,26 synthesized HESHEMA by route 1 and reactions were completed by stirring HEMACI and HES for 5 days at room temperature. Here in this study, after a series of optimization reactions of HEMACI and HES conducted at different temperature conditions, it was found that reactions executed at 80 ºC for 24 h (Scheme 1) gave almost same DS as reported by other researchers.…”

Section: Resultsmentioning

confidence: 99%

“…Swelling ratio of hydrogels can be enhanced up to many times of their dry weight 3,4 and depends mainly upon degree of substitution (DS) of cross-linking substituents, pH and nature of biopolymer used.…”

Section: Introductionmentioning

confidence: 99%

“…Biocompatibility is another basic requirement for such DDS to avoid adverse effects along with their elimination from the body within a limited period of time. 4 Along with biocompatibility and biodegradability, the size and shape of DDS are also important for the release of drug at a specific site.…”

Section: Introductionmentioning

confidence: 99%

“…4 Hydroxyethyl starch (HES), a branched polysaccharide with α(1-4) glycosidic linkage and branching at α(1-6) positions, due to its biocompatibility and biodegradability, is already being used in many pharmaceutical applications. 5 Biocompatible and biodegradable hydrogels can be prepared by cross-linking of such biopolymers after suitable chemical modifications.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Controlled Ondansetron Release Based on Hydroxyethyl Starch Hydroxyethyl Methacrylate

Tahir¹,

Adnan²,

Cho³

et al. 2012

Bulletin of the Korean Chemical Society

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Presented study describes the synthesis of photo cross-linkable and water soluble hydroxyethyl starch hydroxyethyl methacrylate (HESHEMA) samples with different degree of substitution (DS) by functionalization of hydroxyethyl starch (HES) with hydroxyethyl methacrylate (HEMA) or hydroxyethyl methacrylate carbonylimidazole (HEMACI) in DMSO using two different routes. It was revealed that the reaction time for HESHEMA synthesis can be reduced from 5 days to 24 h by conducting the reaction at 80 o C instead of at room temperature. Solubility of HESHEMA was found to be dependent on DS which in turn was dependent on ratio between HES and HEMA or HEMACI. HESHEMA samples with DS > 0.24 depicted insoluble in water, whereas the samples with DS < 0.05 did not form appreciable gel. HESHEMA samples with appropriate DS were converted into hydrogels by cross-linking polymer chains under UV radiations and resulting HESHEMA hydrogels showed swelling up to 1200%. Application of HESHEMA in controlled drug delivery was investigated by diffusion based encapsulation of Ondansetron, a serotonin 5-HT 3 receptor antagonist drug, mainly used for nausea and vomiting treatment.

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mentioning

confidence: 51%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Controlled Ondansetron Release Based on Hydroxyethyl Starch Hydroxyethyl Methacrylate

Tahir¹,

Adnan²,

Cho³

et al. 2012

Bulletin of the Korean Chemical Society

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Mobility of Green Fluorescent Protein in Hydrogel‐Based Drug‐Delivery Systems Studied by Anisotropy and Fluorescence Recovery After Photobleaching

Bertz

Ehlers

Wöhl-Bruhn

et al. 2012

Macromolecular Bioscience

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Modified hydroxyethyl starch is photo-crosslinked in the presence of a green fluorescent protein (GFP) (mTagGFP) to obtain loaded hydrogels as model for a drug-delivery system. An important factor for the protein release is the crosslinking density since a dense network should lead to hindered diffusion. To obtain information on the rotational and translational diffusion of GFP in the hydrogel, mTagGFP is analyzed by fluorescence anisotropy and fluorescence recovery after photo-bleaching experiments using two-photon excitation. The mTagGFP shows a viscosity-retarded rotational and strongly hindered translational diffusion, depending on the polymer concentration. A comparison of anisotropy studies with mTagGFP-loaded microparticles and hydrogel disks allows the polymer concentration to be determined for the microparticles, which has been previously unknown.

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HES-HEMA nanocomposite polymer hydrogels: swelling behavior and characterization

Kamoun

Menzel

2012

J Polym Res

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Organophilic sodium montmorillonite (Na-MMT) and Laponite-RD clays were incorporated into photopolymerizable hydroxyethyl starch (HES) modified with 2-hydroxyethyl methacrylate (HEMA). Swelling, mechanical properties and thermal stability of obtained crosslinked nanocomposite polymers were evaluated. A camphorquinoneamine system was used as photoinitiating system in visible light. The interaction between nano-sized filler particles and polymer hydrogel was evaluated by FT-IR spectroscopy and the platelet distribution was investigated by SEM. An increased thermal stability of nanocomposite polymers upon addition of clay was observed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicating interaction between the clay platelets and the polymer chains. The crosslinking density for HES-HEMA/MMT nanocomposite hydrogels as investigated by swelling measurements increases with increasing the organo-clay content. The mechanical properties of virgin hydrogels were improved by the introduction of organo-clay as evidenced by oscillation rheology measurements. Whereas, the increase in crosslink density and storage modulus with clay content for laponite was found to be increasing for all concentrations investigated, for MMT there is an optimum content of ca. 1.5 wt%.

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A new hydrogel drug delivery system based on Hydroxyethylstarch derivatives

Cited by 21 publications

References 17 publications

Controlled Ondansetron Release Based on Hydroxyethyl Starch Hydroxyethyl Methacrylate

Controlled Ondansetron Release Based on Hydroxyethyl Starch Hydroxyethyl Methacrylate

Mobility of Green Fluorescent Protein in Hydrogel‐Based Drug‐Delivery Systems Studied by Anisotropy and Fluorescence Recovery After Photobleaching

HES-HEMA nanocomposite polymer hydrogels: swelling behavior and characterization

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