Biocompatibility in the Development of Silicone-Hydrogel Lenses

Jacob, Jean T.

doi:10.1097/icl.0b013e31827dbb00

Cited by 40 publications

(23 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The degree of epithelium adhesion against material surfaces influences the material design for many biomedical devices. In the ocular environment, a strong adhesion of the corneal epithelium against contact lenses can induce end-of-day discomfort, [1][2][3][4] and a diminution of comfort during time of wear of soft contact lenses (SCLs) is the most common reason for contact lens discontinuation. 5,6 To develop contact lenses with improved wearer experience, it is both clinically and industrially important to correlate SCL material properties with the wearer comfort.…”

Section: Introductionmentioning

confidence: 99%

“…Extensive literature has reported on the coefficient of friction (CoF) measurements of SCLs as a candidate material property that can link to subject comfort. [1][2][3][4]6 However, CoF measurement results greatly depend on the testing conditions, which can make the replication and interpretation of results difficult. 6,7 In addition, kinetic friction force does not reflect the adhesion force between two surfaces, which fundamentally distinguishes the CoF measurement from the adhesive strength measurement of cornea epithelium against SCLs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tuning Corneal Epithelial Cell Adhesive Strength with Varying Crosslinker Content in Silicone Hydrogel Materials

Liu

Scales

Fuller

2020

Trans. Vis. Sci. Tech.

View full text Add to dashboard Cite

To quantify the effect of silicone hydrogel crosslink density on the adhesion at corneal epithelial cells/silicone hydrogel contact lens interface. Methods: A custom-built rheometer, referred to as the live cell monolayer rheometer, was used to measure the adhesive strengths between corneal epithelial cell monolayers and silicone hydrogel lens surfaces. The resulting stress relaxations of senofilcon Aderived silicone hydrogel materials with varying crosslinking densities and delefilcon A were tested. Senofilcon Alike materials labeled L1, L2, L3, L4, and L5 contained crosslinker concentrations of 1.2, 1.35, 1.5, 1.65, and 1.8 wt%, respectively. The residual modulus measured from the live cell monolayer rheometer provided a direct indication of adhesive attachment. Results: Within the senofilcon-derived series, the adhesive strength shows a surprising minimum with respect to crosslink density. Specifically, L1 (1.20%) has the highest adhesive strength of 39.5 ± 11.2 Pa. The adhesive strength diminishes to a minimum of 11.2 ± 2.1 Pa for L3, whereafter it increases to 14.5 ± 2.5 Pa and 18.1 ± 5.1 Pa for L4 and L5, respectively. The delefilcon A lens exhibits a comparable adhesive strength of 27.8 ± 6.3 Pa to L1. Conclusions: These results demonstrated that increasing the crosslink density has a nonmonotonic influence on the adherence of lenses to mucin-expressing corneal epithelial cells, which suggests a competition mechanism at the cell/lens interface. Translational Relevance: Because the adhesiveness of contact lenses to ocular tissues may impact the comfort level for lens wearers and affect ease of removal, this study suggests that lens adhesion can be optimized through the control of crosslink density.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Tuning Corneal Epithelial Cell Adhesive Strength with Varying Crosslinker Content in Silicone Hydrogel Materials

Liu

Scales

Fuller

2020

Trans. Vis. Sci. Tech.

View full text Add to dashboard Cite

show abstract

“…The three Hy CLs and comfilcon A (SiHy) showed a HI ≥ 40% at t = 1000 s. Among all Hy CLs evaluated, the hilafilcon A material presented the lowest dehydration rate, i.e., the highest HI in this range; the ionic character did not seem to influence the dehydration process. In the case of SiHy materials, comfilcon A reached the highest HI values up to 2000 s, which corresponds to its inherent wettability as a third generation SiHy CL [10]. The remaining SiHy materials showed HI < 40% at t = 1000 s. The ionic material balafilcon A exhibited the slowest dehydration rate, even though its dehydration behaviour is very similar to that of lotrafilcon B, both belonging to the first generation of SiHy CLs.…”

Section: Dehydration Evaluation Of Different CL Materials Preconditiomentioning

confidence: 90%

“…The increased equilibrium WC of the hydrogel polymeric matrix has led to the development of new PHEMA-based hydrogel materials with higher Dk [9]. On the other hand, the first generation of silicone hydrogel biomaterials for CLs was formulated by block polymerization of tris(trimethylsiloxy)silylpropylmethacrylate (TRIS), polydimethylsiloxane (PDMS) and dimethylacrylamide macromers [10] that resulted in higher Dk values than conventional hydrogel CLs. However, the hydrophobic character of the polymeric surface requires treatment to ensure wettability.…”

Section: Introductionmentioning

confidence: 99%

Terahertz-based system for dehydration analysis of hydrogel contact lenses

et al. 2019

View full text Add to dashboard Cite

The use of terahertz-based techniques has grown very fast since they are capable of performing evaluations at molecular level, being very suitable for the analysis of biological samples and biomaterials such as those for contact lenses. These biomaterials are continuously evolving to enhance the lens wearer's comfort by improving their hydration state and surface wettability. Therefore, this study examines a novel terahertz system for the assessment of the temporary in vitro dehydration of hydrogel contact lenses, which provides a new index to assess their state of hydration. Several conventional and silicone hydrogel contact lenses and lens care solutions were analysed. Traditional methods such as the gravimetric determination of water content and the measurement of the static contact angle were also carried out for the validation of the developed system. The dehydration rate measurements of contact lenses obtained with the proposed system correlated with the values provided by traditional methods. As a whole, conventional hydrogel contact lenses exhibited the lowest values for dehydration rate. The tests conducted on various solutions showed a correlation between the wetting action of the solution and the dehydration rate of the contact lens material.

show abstract

“…Vice versa, the tear and corneal metabolism affected by SCL wear may also affect the lenses and cause changes in lens parameters such as water content and lens surface [ 6 ]. Therefore, new materials of SCL with higher Dk above 150 units [10 −11 cm 2 /s (mL O 2 /mL × mmHg)] have been developed to reduce the hypoxic condition of the cornea [ 7 , 8 ]. The Dk value provided by the manufacturers represents that of packaged SCL, applicable to the specific temperature, pH, osmolarity, and buffer solution.…”

Section: Introductionmentioning

confidence: 99%

Influence of Tear Protein Deposition on the Oxygen Permeability of Soft Contact Lenses

Lee

Kim

Park

2017

Journal of Ophthalmology

View full text Add to dashboard Cite

Purpose. To investigate the effect of tear protein deposition on the change in oxygen permeability (Dk) of soft contact lenses (SCL). Methods. Three hydrogel lenses (polymacon, nelfilcon A, and etafilcon A) and two silicon hydrogel lenses (lotrafilcon A and balafilcon A) were investigated. Etafilcon A lenses were incubated in artificial tear solution for 1, 6, 12, and 48 h, whereas the other SCL were incubated for 1, 3, 7, and 14 days. Oxygen permeability was measured using the polarographic method, and lenses were stacked in four layers to correct the boundary effect. Results. The Dk of all investigated SCL was decreased by the protein deposition. Silicone hydrogel lenses showed a smaller deposition of artificial tear proteins than conventional hydrogel lenses. However, their Dk was reduced twofold than those of 3 conventional hydrogel lenses when compared at the same level of protein deposition. Despite a large amount of total deposited protein in etafilcon A lenses, their Dk was more stable than other SCL. Conclusions. From the results, it was revealed that the Dk of SCL is different from the value provided by manufacturers because of the tear protein deposition on surface and/or in pore of SCL; however, the degree of Dk change in SCL was not simply correlated with the amount of tear protein deposition. Thus, it is considered that the correlation between tear protein deposition and properties of lens materials affects Dk change.

show abstract

Biocompatibility in the Development of Silicone-Hydrogel Lenses

Cited by 40 publications

References 44 publications

Tuning Corneal Epithelial Cell Adhesive Strength with Varying Crosslinker Content in Silicone Hydrogel Materials

Tuning Corneal Epithelial Cell Adhesive Strength with Varying Crosslinker Content in Silicone Hydrogel Materials

Terahertz-based system for dehydration analysis of hydrogel contact lenses

Influence of Tear Protein Deposition on the Oxygen Permeability of Soft Contact Lenses

Contact Info

Product

Resources

About