Enzymatic synthesis of dextran-containing hydrogels

Ferreira, Lino; Gil, M.H.; Dordick, Jonathan S.

doi:10.1016/s0142-9612(02)00132-1

Cited by 73 publications

(57 citation statements)

References 31 publications

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“…The DXTA solution was spin-coated on the surface of the PGSA gecko pattern using a speed of 4,000 rpm, which was determined to be optimal for a uniform surface coating. DXTA hydrogels have an elastic modulus between 20 and 60 kPa, depending on the degree of cross-linking as described (21 Biocompatibility studies. The tissue response was determined for nanopatterned PGSA materials (DA ϭ 0.3, DA ϭ 0.3 with 5% PEGDA, and DA ϭ 0.8) and the control material, unpatterned nonresorbable polyurethane.…”

Section: Methodsmentioning

confidence: 99%

A biodegradable and biocompatible gecko-inspired tissue adhesive

Mahdavi

Ferreira

Sundback

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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506

359

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There is a significant medical need for tough biodegradable polymer adhesives that can adapt to or recover from various mechanical deformations while remaining strongly attached to the underlying tissue. We approached this problem by using a polymer poly(glycerol-co-sebacate acrylate) and modifying the surface to mimic the nanotopography of gecko feet, which allows attachment to vertical surfaces. Translation of existing gecko-inspired adhesives for medical applications is complex, as multiple parameters must be optimized, including: biocompatibility, biodegradation, strong adhesive tissue bonding, as well as compliance and conformability to tissue surfaces. Ideally these adhesives would also have the ability to deliver drugs or growth factors to promote healing. As a first demonstration, we have created a gecko-inspired tissue adhesive from a biocompatible and biodegradable elastomer combined with a thin tissue-reactive biocompatible surface coating. Tissue adhesion was optimized by varying dimensions of the nanoscale pillars, including the ratio of tip diameter to pitch and the ratio of tip diameter to base diameter. Coating these nanomolded pillars of biodegradable elastomers with a thin layer of oxidized dextran significantly increased the interfacial adhesion strength on porcine intestine tissue in vitro and in the rat abdominal subfascial in vivo environment. This gecko-inspired medical adhesive may have potential applications for sealing wounds and for replacement or augmentation of sutures or staples.chemical cross-link ͉ medical adhesive ͉ nanotopography ͉ surgical suture

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Section: Methodsmentioning

confidence: 99%

A biodegradable and biocompatible gecko-inspired tissue adhesive

Mahdavi

Ferreira

Sundback

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

506

359

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“…Dextran acrylate with a degree of substitution of 23.3% was synthesized as reported (27). Dextran-based hydrogels (10-mm diameter and 1-mm thickness, before swelling) were obtained by a photopolymerization reaction of aqueous solutions of dextran acrylate.…”

Section: Preparation Of Dextran-based Hydrogels With and Without Ambmentioning

confidence: 99%

Antifungal hydrogels

Zumbuehl

Ferreira

Kuhn

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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106

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Fungi are increasingly identified as major pathogens in bloodstream infections, often involving indwelling devices. Materials with antifungal properties may provide an important deterrent to these infections. Here we describe amphogel, a dextran-based hydrogel into which amphotericin B is adsorbed. Amphogel kills fungi within 2 h of contact and can be reused for at least 53 days without losing its effectiveness against Candida albicans. The antifungal material is biocompatible in vivo and does not cause hemolysis in human blood. Amphogel inoculated with C. albicans and implanted in mice prevents fungal infection. Amphogel also mitigates fungal biofilm formation. An antifungal matrix with these properties could be used to coat a variety of medical devices such as catheters as well as industrial surfaces.antibiotic ͉ Candida albicans ͉ matrix

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“…Figure 1 gives the general scheme of the esterification reaction, and the mechanism of reaction [20]. Dextran reacted with acid anhydride in DMSO in presence of 4-DMAP used as catalyst at 80 °C [21][22][23]. All or some of the hydroxyl groups of dextran were replaced by carboxylic groups to give dextran esters (acetate, propionate and butyrate).…”

Section: Synthesis and Characterization Of Different Dextran Estersmentioning

confidence: 99%

Synthesis and characterization of dextran esters as coating or matrix systems for oral delivery of drugs targeted to the colon.

Beesh¹,

Majewska²,

Th.³

2010

Int. J. Drug Delivery

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Abstract:Different dextran esters with various degrees of substitution (1, 2 and 3) were synthesized by esterification reaction, with three acid anhydrides: acetic anhydride, propionic anhydride, and butyric anhydride, separately. These modified polysaccharides were characterized by FT-IR, 1 H NMR and 13 C NMR spectroscopies. Enzymatic degradation of biopolymers by dextranase was also studied. The polymers showing the best degradation profiles were chosen to design blended free films in combination with a polymethacrylate (Eudragit® RS 30D) as a sustained release system for targeting to the colon. These free films were evaluated by permeability of theophylline used as tracer in different in vitro media of the gastro intestinal tract, in presence or in absence of dextranase. From these studies, it was concluded that dextran esters having the lower degree of substitution and constituted of short carbohydrate chains showed the best and significant enzymatic degradation and could be used as a promising carrier for specific colon drug delivery system.

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Enzymatic synthesis of dextran-containing hydrogels

Cited by 73 publications

References 31 publications

A biodegradable and biocompatible gecko-inspired tissue adhesive

A biodegradable and biocompatible gecko-inspired tissue adhesive

Antifungal hydrogels

Synthesis and characterization of dextran esters as coating or matrix systems for oral delivery of drugs targeted to the colon.

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