Subconjunctival biocompatibility of a viscous bioerodable poly(ortho ester)

Zignani, M.; Bernatchez, Stéphanie F.; Minh, Tri Le; Tabatabay, C.; Anderson, James M.; Gurny, Robert

doi:10.1002/(sici)1097-4636(199802)39:2<277::aid-jbm15>3.0.co;2-a

Cited by 26 publications

(1 citation statement)

References 27 publications

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“…Synthetic biodegradable polymers such as polyesters [3] and polyanhydrides [4] have been crafted into matrices with well-defined release kinetics. However, limits to the compatibility between the degradation products of these polymers with the encapsulated therapeutic [2,5] and the surrounding tissue [6,7], limit applications. Natural polymers such as chitosan [8] and collagen [9] have enabled the design of release matrices with biocompatibility and biodegradability, however often modifications [10] or crosslinking [9] are required.…”

Section: Introductionmentioning

confidence: 99%

Effect of β-sheet crystalline content on mass transfer in silk films

Karve

Gil

McCarthy

et al. 2011

Journal of Membrane Science

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The material properties of silk are favorable for drug delivery due to the ability to control material structure and morphology under ambient, aqueous processing conditions. Mass transport of compounds with varying physical-chemical characteristics was studied in silk fibroin films with control of β-sheet crystalline content. Two compounds, vitamin B12 and fluorescein isothiocynate (FITC) labeled lysozyme were studied in a diffusion apparatus to determine transport through silk films. The films exhibited size exclusion phenomenon with permeability coefficients with contrasting trends with increases in β-sheet crystallinity. The size exclusion phenomenon observed with the two model compounds was characterized by contrasting trends in permeability coefficients of the films as a function of β-sheet crystallinity. The diffusivity of the compounds was examined in the context of free volume theory. Apart from the β-sheet crystallinity, size of the compound and its interactions with silk influenced mass transfer. Diffusivity of vitamin B12 was modeled to define a power law relationship with β-sheet crystallinity. The results of the study demonstrate that diffusion of therapeutic agents though silk fibroin films can be directed to match a desired rate by modulating secondary structure of the silk proteins.

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Section: Introductionmentioning

confidence: 99%

Effect of β-sheet crystalline content on mass transfer in silk films

Karve

Gil

McCarthy

et al. 2011

Journal of Membrane Science

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A viscous bioerodible poly(ortho ester) as a new biomaterial for intraocular application

Einmahl

Behar‐Cohen

Tabatabay

et al. 2000

J. Biomed. Mater. Res.

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The biocompatibility of a viscous, hydrophobic, bioerodible poly(ortho ester) (POE) intended for intraocular application was investigated. POE was evaluated as a blank carrier and as containing modulators of degradation. Each formulation was injected intracamerally and intravitreally in rabbit eyes, and clinical and histological examinations were performed postoperatively for 2 weeks. In the case of intracameral injections, polymer biocompatibility appeared to depend on the amount injected in the anterior chamber. When 50 microL was administered, the polymer degraded within 2 weeks, and clinical observations showed good biocompatibility of POE with no toxicity to the ocular tissues or increase in intraocular pressure. The injection of a larger volume, 100 microL, of POE, appeared inappropriate because of direct contact of polymeric material with the corneal endothelium, and triggered reversible edema and inflammation in the anterior chamber of the eye that regressed after a few days. After intravitreal administration, POE was well tolerated and no inflammatory reaction developed during the observation period. The polymer degraded slowly, appearing as a round whitish bubble in the vitreous cavity. The presence of modulators of degradation both improved POE biocompatibility and prolonged polymer lifetime in the eye. POE appears to be a promising biomaterial for clinical intraocular application.

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Ocular biocompatibility of a poly(ortho ester) characterized by autocatalyzed degradation

Einmahl

Ponsart

Bejjani

et al. 2003

J Biomedical Materials Res

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The biocompatibility of autocatalyzed poly(ortho ester) (POE(70)LA(30)), a viscous, hydrophobic, bioerodible polymer, was investigated. POE(70)LA(30) was synthesized, sterilized by gamma irradiation, and injected in rabbit eyes at adequate volumes through subconjunctival, intracameral, intravitreal, and suprachoroidal routes. Clinical examinations were performed postoperatively at regular time points for 6 mo, and histopathologic analysis was carried out to confirm tissular biocompatibility. After subconjunctival injection, the polymer was well tolerated and persisted in the subconjunctival space for about 5 weeks. In the case of intracameral injections, polymer biocompatibility was good; the POE(70)LA(30) bubble was still present in the anterior chamber for up to 6 mo after injection. No major histopathologic anomalies were detected, with the exception of a localized Descemet membrane thickening. After intravitreal administration, POE(70)LA(30) biocompatibility was excellent, and no inflammatory reaction could be detected during the observation period. The polymer was degraded in approximately 3 mo. Suprachoroidal injections of POE(70)LA(30) were reproducible and well tolerated. POE(70)LA(30) triggered a slight elevation of the retina and choroid upon clinical observation. The polymer was detectable in the suprachoroidal space for about 6 mo. No inflammatory reaction and no major retinal anomalies could be detected by histology. In conclusion, POE(70)LA(30) appears to be a promising biomaterial for intraocular application, potentially providing sustained drug delivery over an extended period of time, with a good tolerance.

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Subconjunctival biocompatibility of a viscous bioerodable poly(ortho ester)

Cited by 26 publications

References 27 publications

Effect of β-sheet crystalline content on mass transfer in silk films

Effect of β-sheet crystalline content on mass transfer in silk films

A viscous bioerodible poly(ortho ester) as a new biomaterial for intraocular application

Ocular biocompatibility of a poly(ortho ester) characterized by autocatalyzed degradation

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