Feasibility study of chitosan as intravitreous tamponade material

Yang, Hong; Wang, Rong; Gu, Qisheng; Zhang, Xiaonong

doi:10.1007/s00417-008-0813-8

Cited by 24 publications

(12 citation statements)

References 13 publications

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“…Chitosan exhibits well-known properties, such as biodegradability, nontoxicity, biocompatibility, mucoadhesiveness, and antibacterial activity (Tang et al, 2010). Due to these favorable properties, chitosan is an important material in ophthalmological research (Basaran & Yazan, 2012;Felt et al, 1999;Fuente et al, 2010;Yang, Wang, Gu, & Zhang, 2008).…”

Section: Introductionmentioning

confidence: 98%

Sulfated chitosan as tear substitute with no antimicrobial activity

Pires

Cunha

Maciel

et al. 2013

Carbohydrate Polymers

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Chitosan of high molar mass and with 82% deacetylation was sulfated using two procedures and characterized. In the first method sample chitosan-S1 was produced using chlorosulfonic acid as the sulfating agent and N,N-dimethylformamide as the medium, and in the second method (chitosan-S2) formic acid was also used. The degrees of sulfation were 0.87 (chitosan-S1) and 0.67 (chitosan-S2). FTIR spectra showed bands at 1230, 800 and 580 cm(-1), attributed to sulfation. Moisture content followed the order: chitosan-S-0.87>chitosan-S-0.67>chitosan. Chain depolymerization was verified by GPC. Aqueous solutions showed pseudoplastic behavior and the viscosity at a concentration of 0.3% (w/v) was higher than that of healthy human tears (close to 3 mPas at shear rate 130 s(-1)). Substitutions in the C2NH and in C6OH groups were verified by NMR. Antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa was not observed. Considering that chitosan-S-0.67 had a higher solubility, less chain depolymerization, higher yield and better thermal stability in comparison with chitosan-S-0.87, the derivative with DS 0.67 offered the greatest potential for use in formulations of tear substitutes.

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Section: Introductionmentioning

confidence: 98%

Sulfated chitosan as tear substitute with no antimicrobial activity

Pires

Cunha

Maciel

et al. 2013

Carbohydrate Polymers

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“…Chemically different compounds such as hyaluronic acid (Healon R ), perfluorinated organic liquids and various synthetic polymers have been tested in the laboratory (Denlinger et al 1980, 1980b, Koster et al 1986, 1986b A fairly recent idea is to explore substances used successfully in other surgical areas (Yang et al 2008). One potential compound is the acrylamide-derivative Bio-Alcamid ® (Polyalkylimide), a clear hydrogel used as subcutaneous filler in reconstructive plastic surgery (Lahiri et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Experimental vitreous tamponade using polyalkylimide hydrogel

Crafoord

Andréasson

Ghosh

2011

Graefes Arch Clin Exp Ophthalmol

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Purpose: To evaluate polyalkyl-imide as a possible vitreous tamponading agent. Methods:A 20 gauge pars plana vitrectomy and posterior vitreous detachment were performed in the right eye of six pigmented rabbits. Approximately 1 ml of viscoelastic gel, polyalkyl-imide (Bio-Alcamid ® ) was thereafter injected into the vitreous space. Full-field ERG and intraocular pressure (IOP, Tonopen) was measured pre-and postoperatively at regular intervals up to 28 days. At day 6 or 28, the rabbits were sacrificed and the eyes were examined macroscopically, photographed, and prepared for histological examination with routine microscopy. Results:The viscoelastic hydrogel was successfully injected and remained translucent with preserved gel properties throughout the postoperative period. The postoperative IOP was unchanged compared to preoperative values. Five of six eyes displayed retinal edema or pigmentary changes centrally while the periphery appeared intact. ERG recordings showed a radical decrease in rod and cone derived B-wave amplitudes. Histological examination confirmed varying degrees of edema combined with neuronal cell death within the retinal layers in the central part of the fundus while the peripheral part appeared intact. Conclusion:Polyalkyl-imide displays favourable physical properties when used as a vitreous tamponade. However, the hydrogel causes functional and morphological retinal damage when in direct contact with the inner retina. Possible pathological mechanisms include osmotic imbalance and direct toxic effects, and modification of biochemical properties is warranted before clinical use will be possible.

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“…Recent tamponade strategies therefore aim at hydrophilic, hydrogel-based systems (reviewed by Su et al 11 ). In addition to synthetic polymers, biopolymers such as hyaluronic acid, [12][13][14][15][16][17] collagen, 17,18 gellan, 16,19 chitosan, 20,21 and alginate 21 were investigated for the preparation of hydrophilic retinal tamponades. However, previous concepts were mainly limited by intransparency, deviating refractive indices, fast degradation, or insufficient biocompatibility, especially because of lack of substance purity or toxic cross-linking agents.…”

Section: Introductionmentioning

confidence: 99%

Alginate- and Hyaluronic Acid–Based Hydrogels as Vitreous Substitutes: An In Vitro Evaluation

Schulz

Rickmann

Wahl

et al. 2020

Trans. Vis. Sci. Tech.

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Purpose To study alginate- and hyaluronic acid–based hydrogels in vitro as vitreous substitutes. Methods Biopolymeric hydrogels based on high-molecular alginate (0.5% and 1.0%) and hyaluronic acid (1.0% and Healaflow) were compared with extracted human vitreous bodies and silicone oil (SIL-5000) regarding their optical properties (refractive index, transmission) and viscoelastic characteristics (storage modulus G′, loss modulus G″). The cytotoxic (metabolic activity, apoptosis) and antiproliferative profiles were determined using cultured human fibroblasts, ARPE-19, and photoreceptor cells. The hydrogel systems were applied to human fetal retinal pigment epithelial cells cultured for two months until maximum transepithelial electrical resistance (TEER) to investigate the effect of the gel matrices on tight junctions using TEER measurements and immunostainings against the tight junction protein ZO-1. Results Tested alginate- and hyaluronic acid–based hydrogels resembled the natural refractive index of human vitreous bodies (1.3356–1.3360) in contrast to SIL-5000 (1.4034) and showed high optical transparency (>90%) within the visible light region. The biopolymeric hydrogels exhibited viscoelastic properties similar to juvenile vitreous bodies with G′>G″ adjustable via different gelation times, contrary to SIL-5000 (G′

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Feasibility study of chitosan as intravitreous tamponade material

Cited by 24 publications

References 13 publications

Sulfated chitosan as tear substitute with no antimicrobial activity

Sulfated chitosan as tear substitute with no antimicrobial activity

Experimental vitreous tamponade using polyalkylimide hydrogel

Alginate- and Hyaluronic Acid–Based Hydrogels as Vitreous Substitutes: An In Vitro Evaluation

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