Molecular dynamics simulation study of P (VP-co-HEMA) hydrogels: Effect of water content on equilibrium structures and mechanical properties

Lee, Seung Geol; Brunello, Giuseppe F.; Jang, Seung Soon; Bucknall, David G.

doi:10.1016/j.biomaterials.2009.07.035

Cited by 75 publications

(61 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PVP increases the hydrophilicity of the material and has self-lubricant properties essential to the comfort and good performance of the contact lenses [27,28]. One hydrogel was prepared using an anhydrous mixture.…”

mentioning

confidence: 99%

About the effect of eye blinking on drug release from pHEMA-based hydrogels: anin vitrostudy

Galante

Paradiso

Moutinho

et al. 2015

Journal of Biomaterials Science, Polymer Edition

View full text Add to dashboard Cite

Abstract:The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. PHEMA-UV revealed some superficial porosity and a lower short range order than PHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant in in vivo conditions. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems CorporationConversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems CorporationAbout the effect of eye blinking on drug release from pHEMA based hydrogels:an in vitro study The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before.Two poly-2-hydroxyethylmethacrylate based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. PHEMA-UV revealed some superficial porosity and a lower short range order than PHEMA-T.We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, show...

show abstract

mentioning

confidence: 99%

About the effect of eye blinking on drug release from pHEMA-based hydrogels: anin vitrostudy

Galante

Paradiso

Moutinho

et al. 2015

Journal of Biomaterials Science, Polymer Edition

View full text Add to dashboard Cite

show abstract

“…Because of the significant difference in the reactivity between VP and HEMA, the consumption of HEMA is faster than that of VP during polymerization, which leads to compositional heterogeneity in the copolymer chains [53] and a broad microstructural distribution [27]. Indeed, it was reported from our previous study [54] that the mechanical properties of P(VP-co-HEMA) hydrogel depend on the monomeric sequence of P(VP-co-HEMA), and the VP monomers (especially in a blocky sequence) are responsible for stress relaxation.…”

Section: Introductionmentioning

confidence: 87%

“…Therefore, our primary objective in this study is to elucidate the effect of the monomeric sequence on the transport properties of P(VP-co-HEMA) hydrogel with various water contents. For this, we simulated the blocky and random P(VP-co-HEMA) hydrogel systems as reported in our previous studies [54,55] with guest molecules of D-glucose and ascorbic acid (Fig. 1h, i).…”

Section: Introductionmentioning

confidence: 99%

Effect of monomeric sequence on transport properties of d-glucose and ascorbic acid in poly(VP-co-HEMA) hydrogels with various water contents: molecular dynamics simulation approach

et al. 2012

Self Cite

View full text Add to dashboard Cite

We have used full-atomistic molecular dynamics (MD) simulations of both random and blocky sequence hydrogel networks of poly(N-vinyl-2-pyrrolidone-co-2-hydroxyethyl methacrylate) (P(VP-co-HEMA)) with a composition of VP/HEMA = 37:13 to investigate the effect of the monomeric sequence and the water content on the transport properties of ascorbic acid and D-glucose at 310.15 K. The degrees of randomness of the monomer sequence for the random and the blocky copolymers were 1.170 and 0.104, respectively, and the degree of polymerization was fixed at 50. By analyzing the pair correlation functions, it was found that for both monomeric sequences, the guest molecules (i.e., ascorbic acid and D-glucose) have greater accessibility to the VP units than to the HEMA units due to the higher hydrophilicity of VP compared to HEMA units. While the monomeric sequence effect on the P(VPco-HEMA) hydrogel is clearly observed with 20 wt. % water content, the effect is significantly reduced with 40 wt. % water content and disappears completely with 80 wt. % water content. This is because the hydrophilic guest molecules are more likely to be associated with water molecules than with the polymer network at the high water content. By analyzing the diffusion of the guest molecules and the inner-surface area, it is also found that the guest molecules are confined in the system at 20 wt. % water content, resulting in highly anomalous sub-diffusion. Therefore, at low water content, the diffusion of the guest molecules in the hydrogel is directly affected by the monomeric sequence through the interaction of guest molecules with the monomeric units, whereas such monomeric sequence effects are significantly reduced with increasing water content.

show abstract

“…Young's modulus (MPa) maximum tensile strength of the biomaterial is influenced by the presence of water, which interferes in the interaction of polymer chains [52]. The tensile strength of PVA was reduced by the incorporation of BC.…”

Section: Biomaterialsmentioning

confidence: 99%

“…The tensile strength of PVA was reduced by the incorporation of BC. This is explained by the fact that, in the wet state, BC acts as a stress concentrator, because of the interference of water located between the matrix and the reinforcement, at the interfaces in the composite [52]. A Young's modulus of ca.…”

Section: Biomaterialsmentioning

confidence: 99%

Bioactive 3D-Shaped Wound Dressings Synthesized from Bacterial Cellulose: Effect on Cell Adhesion of Polyvinyl Alcohol Integrated In Situ

Osorio

Velásquez-Cock

Múnera

et al. 2017

International Journal of Polymer Science

View full text Add to dashboard Cite

We investigated wound dressing composites comprising fibrils of bacterial cellulose (BC) grown by fermentation in the presence of polyvinyl alcohol (PVA) followed by physical crosslinking. The reference biointerface, neat BC, favoured adhesion of fibroblasts owing to size exclusion effects. Furthermore, it resisted migration across the biomaterial. Such effects were minimized in the case of PVA/BC membranes. Therefore, the latter are suggested in cases where cell adhesion is to be avoided, for instance, in the design of interactive wound dressings with facile exudate control. The bioactivity and other properties of the membranes were related to their morphology and structure and considered those of collagen fibres. Bioactive materials were produced by simple 3D templating of BC during growth and proposed for burn and skin ulcer treatment.

show abstract

Molecular dynamics simulation study of P (VP-co-HEMA) hydrogels: Effect of water content on equilibrium structures and mechanical properties

Cited by 75 publications

References 59 publications

About the effect of eye blinking on drug release from pHEMA-based hydrogels: anin vitrostudy

About the effect of eye blinking on drug release from pHEMA-based hydrogels: anin vitrostudy

Effect of monomeric sequence on transport properties of d-glucose and ascorbic acid in poly(VP-co-HEMA) hydrogels with various water contents: molecular dynamics simulation approach

Bioactive 3D-Shaped Wound Dressings Synthesized from Bacterial Cellulose: Effect on Cell Adhesion of Polyvinyl Alcohol Integrated In Situ

Contact Info

Product

Resources

About