Contact-angle analysis of intraocular lenses

Cunanan, Crystal; Ghazizadeh, Massoud; Buchen, Shelley Y.; Knight, Patricia M.

doi:10.1016/s0886-3350(98)80322-2

Cited by 51 publications

(36 citation statements)

References 17 publications

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“…Contact angle readings in particular assess surface hydrophilicity, which can be used as a reliable parameter for predicting uveal and capsular biocompatibility [12]. The heparin-surface-modified IOL revealed the lowest contact angle values.…”

Section: Discussionmentioning

confidence: 99%

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Material Properties of Various Intraocular Lenses in an Experimental Study

et al. 2003

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Introduction: With the recent introduction of small-incision cataract surgery, requirements for intraocular lens (IOL) flexibility, strength and hydrophilicity have rapidly evolved. The IOL surface, however, remains a critical factor influencing uveal biocompatibility. Purpose: To objectively quantify factors of material properties of various IOLs using contact angle measurements, differential scanning calorimetry, dynamic-mechanical measurements and scanning electron microscopy. Material and Methods: In our study, 17 currently available IOLs were investigated using contact angle measurements to assess hydrophilicity and biocompatibility, as well as differential scanning calorimetry for the estimation of glass transition temperature. Mechanical capacity and flexibility were investigated using dynamic-mechanical measurements. Additional analysis of the IOL surface was performed using scanning electron microscopy. Results: The contact angle measurements of the studied IOLs revealed similar values within each group. The silicone IOLs had values between 106 and 119°. The PMMA IOLs were found to have a narrower range of values, between 73.2 and 75.5°. Lenses made of hydrogel had values between 59.2 and 69.1°. The heparin-modified surface showed the lowest contact angle of 56.5°. The glass transition temperature was determined by dynamic differential scanning calorimetry. The resulting values were between 118.8 and 113.5°C for PMMA IOLs, 15.5 and 14.0°C for acrylic IOLs, and –91.7 and –119.6°C for silicone IOLs. The dynamic-mechanical measurements revealed that PMMA lenses manifested characteristics similar to glass, whereas silicone lenses had characteristics similar to rubber. Acrylic lenses were between rubber and glass. Scanning electron microscopy revealed smooth dispersion of fibrin on hydrophobic IOLs and a relative lack of fibrin adhesion on hydrophilic materials. Conclusion: These results demonstrate that material properties of various IOL materials are consistent within classes of IOL materials. This suggests that the intraoperative and postoperative behavior of an IOL is predictable and related to its composition, thus allowing surgeons to choose IOLs more appropriate for different surgical situations and individual patient characteristics.

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Section: Discussionmentioning

confidence: 99%

“…In the future, IOL materials and designs may be routinely tested in vitro to understand their interactions with cells, proteins and tissues, thus streamlining the process of product development and making surgery safer and more predictable for patients [1, 12, 20]. …”

Section: Discussionmentioning

confidence: 99%

Material Properties of Various Intraocular Lenses in an Experimental Study

et al. 2003

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“…Contact angle measurements are sensitive to the chemical composition of the top molecular layer and are relatively simple, inexpensive, and a widely accepted technique for characterising flat polymer surfaces, in terms of wetting and adhesion properties of the polymer surfaces. If it is desired to investigate the wetting behaviour of highly hydrated or solvated materials surfaces and even the interaction between such surfaces and proteins [21,30], the captive bubble technique has to be used [31][32][33]. However, this technique has severe limitations in its ability to assess the wettability of 'wet' porous polymer structures.…”

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confidence: 99%

Characterisation of ‘wet’ polymer surfaces for tissue engineering applications: Are flat surfaces a suitable model for complex structures?

Safinia

Blaker

Maquet³

et al. 2005

E-Polymers

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Tissue engineering scaffolds are 3D constructs that simulate the growth environment in vivo. The present work aims to address the question of whether thin films, i.e., flat surfaces, are a suitable model for more complex 3D structures? With this in mind a complete study of the morphology and surface chemistry of poly(D,Llactide) (PDLLA) substrates, fabricated into two different structures, is presented. The polymer structures studied include a 3D, porous, foam-like scaffold prepared by the thermally induced phase separation (TIPS) method and flat polymer thin films made by solvent casting. Based on the maximum bubble point test, a new method to assess the wettability of wet pore wall surfaces inside highly porous 3D structures was developed and tested. The maximum pore diameter determined using the maximum bubble point test for the total wetting liquids was confirmed through image analysis of scanning electron micrographs. The method allows the determination of the contact angle between the wet pore wall and a contacting liquid. The captive bubble method was employed to characterise the wettability of flat polymer films in contact with water. Both structures were further characterised using zeta-(ζ-) potential measurements to assess the surface chemistry of the polymer. The results demonstrate that PDLLA contains acidic functional groups and is hydrophobic. In order to evaluate the sensitivity of the test methods, the polymer surfaces were modified by protein adsorption using fibronectin and collagen. ζ-Potential and wettability measurements show that proteins indeed adsorb on virgin PDLLA surfaces. Protein adsorption causes the wettability of the PDLLA for water to improve. Our results strongly indicate that flat surfaces are not a suitable model for surfaces in complex 3D structures such as highly porous tissue engineering scaffolds. Such scaffolds must be characterised as a 3D system.

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“…Indeed, the hydrophobic character of the biomaterial surfaces studied is not investigated in these works. In fact only few authors have studied the wetting behavior of commercially available IOLs [11,12,13,14,15]. …”

Section: Discussionmentioning

confidence: 99%

“…Few authors have tried to determine the hydrophobicity parameters of commercially available intraocular lenses [11,12,13,14,15]. To investigate the wetting behavior of IOLs most of them have presented contact angle measurements between IOL surfaces and characterized test liquids: a high value contact angle would indicate a more hydrophobic surface [10].…”

Section: Introductionmentioning

confidence: 99%

Calculation of Intraocular Lens Surface Free Energy and its Components from Contact Angle Measurements

et al. 2013

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One of the most important biomaterial characteristics involved in bacterial adhesion on intraocular lenses (IOLs) is hydrophobicity. We calculated the hydrophobicity parameters of IOLs made of 6 different materials (polymethylmethacrylate, PMMA, heparin surface-modified PMMA, HSM-PMMA, silicone, hydrophilic and hydrophobic acrylics and collamer). Values of IOL surface free energy components were determined from contact angle measurements, using the Fowkes, Owens-Wendt and Good-van Oss calculations. Contact angles were higher for silicone and hydrophobic acrylic materials and lower for collamer and hydrophilic acrylic materials. The values of IOL surface free energy components obtained with the 3 different calculations were homogenous. According to the Owens-Wendt calculation, the IOLs could be separated into dispersive implants (hydrophobic acrylic, silicone and PMMA) and polar implants (collamer, hydrophilic acrylic and HSM-PMMA).

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Contact-angle analysis of intraocular lenses

Abstract: Contact-angle measurements differed depending on the test conditions. Proper choice of contact-angle measurement method can generate useful information about a material surface and its potential biomaterial interactions.

Cited by 51 publications

References 17 publications

Material Properties of Various Intraocular Lenses in an Experimental Study

Material Properties of Various Intraocular Lenses in an Experimental Study

Characterisation of ‘wet’ polymer surfaces for tissue engineering applications: Are flat surfaces a suitable model for complex structures?

Calculation of Intraocular Lens Surface Free Energy and its Components from Contact Angle Measurements

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