Biological Mineralization of Hydrophilic Intraocular Lenses

Koutsoukos, Petros G.; Natsi, Panagiota D.; Gartaganis, Sotirios P.; Gartaganis, Panos S

doi:10.3390/cryst12101418

Cited by 4 publications

(5 citation statements)

References 29 publications

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“…As may be seen, along with the increasing GO concentration of the suspensions equilibrated with HAP, which resulted in a higher GO retention by the crystals (confirmed by the TGA analysis, which showed proportionally higher mass loss at the temperature domain between 300 and 450 °C), the crystal growth rate of the hydroxyapatite (HAP) formation also increased. The increase in the crystal growth rate up to equilibration with 10 The morphology of HAP crystals grown at constant supersaturation was the same as reported earlier for the PHEMA IOLs and consisted of prismatic HAP nanocrystals [10][11][12], as shown in the SEM photos in Figure 17. × 10 −4 % w/v concentration of GO suspension showed a tendency to level off; however, for the solid equilibrated with 20 × 10 −4 % w/v GO suspension, the rate of crystal growth increased dramatically.…”

Section: Mineralization Experimentssupporting

confidence: 77%

“…The apparent conclusion is that the presence of GO on HAP crystals resulted in the enhancement of the active crystal growth sites, possibly via the contribution of the ionized carboxyl groups of GO. The morphology of HAP crystals grown at constant supersaturation was the same as reported earlier for the PHEMA IOLs and consisted of prismatic HAP nanocrystals [10][11][12], as shown in the SEM photos in Figure 17. Next, hydrophilic IOLs modified via equilibration with GO suspensions, both before and after reduction with phenyl hydrazine, were investigated.…”

Section: Mineralization Experimentssupporting

confidence: 56%

“…In the case of IOLs, copolymers are included to control water uptake, UV absorption, etc. Recent studies suggested that PHEMA promotes nucleation and growth of hydroxyapatite (Ca 5 (PO 4 ) 3 OH, HAP) upon contact with solutions supersaturated with respect to HAP [10][11][12]. The next generation of biomaterials suitable for the fabrication of IOLs fulfill the requirements of biocompatibility, refractive index, and prevention of posterior capsular opacification.…”

Section: Introductionmentioning

confidence: 99%

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Graphene-Derivative Coatings for the Prevention of Opacification Due to Calcification of Hydrophilic Intraocular Lenses

Natsi,

Kanakis,

Sygellou

et al. 2024

Crystals

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The widespread use of hydrophilic intraocular lenses (IOLs) in eye surgery, fabricated by poly-2-(hydroxyethyl methacrylate) (PHEMA), has highlighted their calcification as a serious problem, implying that their surgical explantation is a rather risky process. The field of biomaterials has been developing rapidly in recent years, with research interest turning to the development of novel materials which involve either copolymers of PHEMA or protective functional coatings. Graphene coatings are particularly attractive because of their respective unique properties. In the present work, we present the results of the investigation of the development of graphene coatings on hydrophilic IOLs and their subsequent performance with respect to calcification opacification. Hydrophilic IOLs with a water content of 18% by weight were coated with graphene oxide (GO) by equilibration with GO suspensions in water. The concentrations of the suspensions ranged from 1 × 10−4 to 20 × 10−4% w/v. The GO suspensions were equilibrated with the IOLs for 5 days at a constant temperature, 37 °C, and rotated in 30 mL tubes end over end. This treatment resulted in the formation of a uniform coating of GO on the IOLs verified by scanning electron microscopy (SEM) and other physicochemical methods. The contact angle of the GO-coated IOLs decreased significantly in comparison with the uncoated IOLs. The GO-coated IOLs exhibited a higher tendency to calcify in supersaturated solutions simulating aqueous humor (SAH). The growth rate of hydroxyapatite (Ca5(PO4)3OH, HAP) on GO-coated IOLs was higher in comparison with the respective untreated IOLs. The conversion of the GO coating via a reduction with phenyl hydrazine resulted in the formation of a reduced-graphene (rGO) surface film, as identified by Raman and XPS spectroscopy. The rGO film was hydrophobic (contact angle 100°) and did not calcify in supersaturated calcium phosphate solutions.

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Section: Mineralization Experimentssupporting

confidence: 77%

Section: Mineralization Experimentssupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

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Graphene-Derivative Coatings for the Prevention of Opacification Due to Calcification of Hydrophilic Intraocular Lenses

Natsi,

Kanakis,

Sygellou

et al. 2024

Crystals

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“… 1 However, the potential of an IOL material to be transparent must be taken into consideration when evaluating the long-term biocompatibility of the material, particularly for the hydrophilic acrylic IOLs, which are at a higher risk of developing calcification of the lens material. 2 – 4 Here, we present the clinical and laboratory characteristics of an unusual case of hydrophilic IOL opacification 23 years after a successful phacoemulsification procedure due to traumatic cataracts.…”

Section: Introductionmentioning

confidence: 99%

A unique late-onset intraocular lens opacification 23 years after implantation: a clinical and laboratory case report

Gartaganis,

Natsi,

Gartaganis

et al. 2024

Ophthalmol Eye Dis

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We report an unusual, rare case of opacification of the hydrophilic acrylic intraocular lens (IOL) 23 years after the initial surgery with significant visual deterioration. Opacification of the hydrophilic acrylic IOL was primarily due to the formation of folds on the surface of the lens material, and less so due to calcium phosphate deposits. Calcification opacification can be attributed to recent events, as evidenced by deposits of dicalcium phosphate dihydrate (CaHPO42H2O) and octacalcium phosphate (Ca8H2(PO4)65H2O), both of which are transient calcium phosphate phases, converting hydrolytically to the thermodynamically most stable hydroxyapatite (Ca10(PO4)6(OH)2). To our knowledge, this case of hydrophilic acrylic IOL opacification is the only one that has been described so late, 23 years after cataract surgery.

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“…Hydrogels of this type are extensively used for the fabrication of biomaterials. Recent studies suggested that PHEMA promotes nucleation and growth of hydroxyapatite (Ca5(PO4)3OH, HAP) upon contact with solutions supersaturated with respect to HAP [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Graphene Derivatives Coatings for the Prevention of Opacification Due to Calcification of Hydrophilic Intraocular Lenses

NATSI,

KANAKIS,

SYGELLOU

et al. 2023

Preprint

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The widespread use of hydrophilic intraocular lenses (IOL) in eye surgery, fabricated by poly-2- (hydroxyethylmethacrylic acid) (PHEMA), has highlighted their calcification as a serious problem, which implies their surgical explantation a rather risky process. The field of biomaterials has been developing rapidly in recent years with research interest turning to the development of novel ma-terials which involve either copolymers of PHEMA or protective functional coatings. Graphene coatings are particularly attractive because of the respective unique properties. In the present work we present the results of the investigation of the development of graphene coatings on hydrophilic IOLs and their subsequent performance with respect to calcification opacification. Hydrophilic IOL with water content of 18% by weight, were coated with graphene oxide (GO) by equilibration with GO suspensions in water. The concentrations of the suspensions ranged 1x10-4 to 20x10-4 % w/v. The GO suspensions were equilibrated with the IOLs for 5 days at constant temperature, 37°C, rotated in 30 mL tubes end over end. This treatment, resulted in the formation of a uniform coating of GO on the IOLs verified by scanning electron microscopy (SEM) and other physicochemical methods. The contact angle of the GO coated IOLs decreased significantly in comparison with the uncoated. The GO-coated IOLs exhibited higher tendency to calcify in supersaturated solutions simulating aqueous humor (SAH). The growth rate of hydroxyapatite (Ca5(PO4)3OH, HAP) on GO-coated IOLs was higher, in comparison with the respective untreated IOLs. The conversion of the GO coating by reduction with phenyl hydrazine resulted in the formation of reduced graphene (rGO) surface film, identified by Raman and XPS spectroscopy. of the rGO film was hydrophobic (contact angle 100 o) and did not calcify in supersaturated calcium phosphate solutions.

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Biological Mineralization of Hydrophilic Intraocular Lenses

Cited by 4 publications

References 29 publications

Graphene-Derivative Coatings for the Prevention of Opacification Due to Calcification of Hydrophilic Intraocular Lenses

Graphene-Derivative Coatings for the Prevention of Opacification Due to Calcification of Hydrophilic Intraocular Lenses

A unique late-onset intraocular lens opacification 23 years after implantation: a clinical and laboratory case report

Graphene Derivatives Coatings for the Prevention of Opacification Due to Calcification of Hydrophilic Intraocular Lenses

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