Depth Profile Assessment of the Early Phase Deposition of Lysozyme on Soft Contact Lens Materials Using a Novel In Vitro Eye Model

Qiao, Han; Phan, Chau-Minh; Walther, Harald; Subbaraman, Lakshman N.; Jones, Lyndon

doi:10.1097/icl.0000000000000397

Cited by 10 publications

(16 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this model does not simulate appropriate tear volume and natural tear flow [20,21], air exposure, and mechanical rubbing, which are factors which can significantly impact release kinetics. We have recently developed an in vitro model (OcuFlow) that allows lenses to be examined on a corneal-shaped profile that exposes the lens to a blinkactuator that mimics the action of the lid blinking, mimics the inter-blink period, and also flows an artificial tear fluid over the lens at physiologically relevant rates of replenishment and quantity, and permits any elute from the lens to be captured and subsequently analysed [22,[28][29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model

Phan¹,

Walther²,

Smith

et al. 2018

Journal of Biomaterials Science, Polymer Edition

Self Cite

View full text Add to dashboard Cite

The traditional method to measure release of components from CLs is a vial containing a static volume of PBS (phosphate buffered saline). However, this model does not simulate physiologically relevant tear volume and natural tear flow, air exposure, and mechanical rubbing. These factors can significantly impact release kinetics. We have developed an in vitro eye model (OcuFlow) that simulates these parameters. The aim of the study was to measure the release of PEG (polyethylene glycol), and HPMC (hydroxypropyl methylcellulose) from a daily disposable hydrogel contact lens material (nelfilcon A; Dailies AquaComfort PLUS; DACP;) over 24 hrs using the OcuFlow platform. The elution of PEG and HPMC from DACP lenses was analyzed using LCMS (liquid chromatography mass spectrometry). The release of all wetting agents from the lenses followed a burst release pattern, which occurred within the first 1.5 hrs (P < 0.05). The release of PEG was greater than that of HPMC (P < 0.05). The amount of PEG and HPMC released at any given time was less than 1% of the amount in the blister pack solution. Our results suggest that HPMC and PEG are rapidly released from the CL.

show abstract

Section: Introductionmentioning

confidence: 99%

Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model

Phan¹,

Walther²,

Smith

et al. 2018

Journal of Biomaterials Science, Polymer Edition

Self Cite

View full text Add to dashboard Cite

show abstract

“…First, the material properties of the eyelid and eyeball needed to be highly wettable for the TF to appropriately spread. A hydrophobic material such as PDMS, which was used in previous eye models16,17,19–22,27 would not allow for a proper tear layer to form. Secondly, the eyelid also needed to be flexible to ensure direct contact between the eyelid and the corneal surface.…”

Section: Discussionmentioning

confidence: 99%

“…The aforementioned reasons have led various groups to develop in vitro eye models that attempt to mimic key parameters on the eye 15–26. Our group has previously developed an in vitro model designed to physiologically mimic tear flow, tear volume, air exposure, and the mechanical rubbing produced during blinking 17,18,20–22,27. Not surprisingly, results obtained for TF deposition on contact lenses using this model revealed stark differences to a simple vial model 17,18.…”

Section: Introductionmentioning

confidence: 99%

“…Our group has previously developed an in vitro model designed to physiologically mimic tear flow, tear volume, air exposure, and the mechanical rubbing produced during blinking 17,18,20–22,27. Not surprisingly, results obtained for TF deposition on contact lenses using this model revealed stark differences to a simple vial model 17,18. However, while the model presented an arguably enhanced testing alternative than a vial, it still lacked the physiological blink mechanism that is vital for adequately simulating the dynamic TF layer.…”

Section: Introductionmentioning

confidence: 99%

“…The underlying problem with previous in vitro eye models were that they were made from hydrophobic polymers, such as polydimethylsiloxane 17,18,20–22,27. Consequently, these materials were unable to simulate two critically important aspects of the corneal surface: wettability and water content (WC).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Development of an Eye Model With a Physiological Blink Mechanism

Phan

Walther

Qiao

et al. 2019

Trans. Vis. Sci. Tech.

Self Cite

View full text Add to dashboard Cite

Purpose To develop an eye model with a physiological blink mechanism. Methods All parts of the eye model were designed using computer-aided design software. The eyelid consisted of a unique 3D printed structure containing teeth to physically secure a flexible membrane. Both the eyeball and eyelid membrane were synthesized using polyvinyl alcohol (PVA). Four molecular weights of PVA (89–98, 85–124, 130, and 146–186 kDa) were tested at a range of concentrations between 5% and 30% weight/volume. The wettability and water content of these materials were compared with the bovine cornea and sclera. The model was connected to a microfluidic pump, which delivers artificial tear solution (ATS) to the eyelid. A corneal topographer was used to evaluate the tear break-up and tear film regeneration. Results The eyelid flexes and slides across the eyeball during each blink, which ensures direct contact between the two surfaces. When loaded with an ATS, this mechanism evenly spreads the solution over the eyeball to generate an artificial tear film. The artificial tear film in this eye model had a tear break-up time (TBUT) of 5.13 ± 0.09 seconds at 1.4 μL/min flow rate, 6 blinks/min, and <25% humidity. Conclusions This model simulates a physiological blink actuation and an artificial tear film layer. Future studies will examine variations in flow rates and ATS composition to simulate clinical values of TBUT. Translational Relevance The eye model could be used to study in vitro TBUT, tear deposition, and simple drug delivery.

show abstract

Analysis of polyvinyl alcohol release from commercially available daily disposable contact lenses using an in vitro eye model

et al. 2018

View full text Add to dashboard Cite

The purpose of this work was to determine the release of polyvinyl alcohol (PVA) from etafilcon A, omafilcon A, and nelfilcon A daily disposable hydrogel contact lenses using a novel in vitro model. PVA is an ocular lubricant that can be found in multiple formulations of artificial tears. Nelfilcon A innately contains PVA, so only the release of PVA from this lens was evaluated. Etafilcon A and omafilcon A lenses were incubated in a PBS solution containing PVA. The release of PVA was evaluated using a novel in vitro blink platform with Milli‐Q water and PBS under various blink conditions and flow rates. Nelfilcon A lenses significantly released more PVA than other lenses at 0.5 and 1.5 h in both PBS and Milli‐Q water ( p < 0.001). For nelfilcon A, there was no statistical significance between the release profiles of PVA between the blink and no‐blink conditions, or for the various flow rates ( p > 0.05). All tested groups and lenses showed a burst release within the first 4.5 h and rapidly plateaued thereafter. The current study demonstrates that releasable PVA (whether through uptake or through being inherently available from the material) is loosely bound on hydrogel lenses, and the majority is released within 4.5 h. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1662–1668, 2019.

show abstract

Depth Profile Assessment of the Early Phase Deposition of Lysozyme on Soft Contact Lens Materials Using a Novel In Vitro Eye Model

Cited by 10 publications

References 55 publications

Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model

Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model

Development of an Eye Model With a Physiological Blink Mechanism

Analysis of polyvinyl alcohol release from commercially available daily disposable contact lenses using an in vitro eye model

Contact Info

Product

Resources

About