Investigation of the rheological and mechanical properties of a polystyrene‐polyisobutylene‐polystyrene triblock copolymer and its blends with polystyrene

Antony, Prince; Puskás, Judit E.; Kontopoulou, Marianna

doi:10.1002/pen.10021

Cited by 34 publications

(24 citation statements)

References 19 publications

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“…As described above, PIB is the main component of the thermoplastic elastomer SIBS, [40][41][42] which is used in combination with PTX as the coating material on the clinical TAXUS TM 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 5 stent. 43,44 PTX is widely used in anticancer treatment, but because of its potent anti-mitotic activity, 45,46 it is also an excellent anti-proliferative for use with cardiovascular stents.…”

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confidence: 99%

Covalent Polyisobutylene–Paclitaxel Conjugates for Controlled Release from Potential Vascular Stent Coatings

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McEachran

Sran

et al. 2015

ACS Appl. Mater. Interfaces

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The development of covalent polyisobutylene (PIB)-paclitaxel (PTX) conjugates as a potential approach to controlling drug release from vascular stent coatings is described. PIB-PTX materials containing ∼24 and ∼48 wt % PTX, conjugated via ester linkages, were prepared. The PTX release profiles were compared with those of physical mixtures of PTX with carboxylic acid-functionalized PIB and with the triblock copolymer polystyrene-b-PIB-b-polystyrene (SIBS). Covalent conjugation led to significantly slower drug release. Atomic force microscopy imaging of coatings of the materials suggested that the physical mixtures exhibited multiple domains corresponding to phase separation, whereas the materials in which PTX was covalently conjugated appeared homogeneous. Coatings of the conjugated materials on stainless steel surfaces suffered less surface erosion than the physically mixed materials, remained intact, and adhered well to the surface throughout the thirty-five day study. Tensile testing and rheological studies suggested that the incorporation of PTX into the polymer introduces similar physical changes to the PIB as the incorporation of a glassy polystyrene block does in SIBS. Cytotoxicity assays showed that the coatings did not release toxic levels of PTX or other species into a cell culture medium over a 24 h period, yet the levels of PTX in the materials were sufficient to prevent C2C12 cells from adhering to and proliferating on them. Overall, these results indicate that covalent PIB-PTX conjugates have promise as coatings for vascular stents.

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mentioning

confidence: 99%

Covalent Polyisobutylene–Paclitaxel Conjugates for Controlled Release from Potential Vascular Stent Coatings

Trant

McEachran

Sran

et al. 2015

ACS Appl. Mater. Interfaces

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“…It can therefore be concluded that all results in this study are computed for realistic ranges of interface strengths and for commercially relevant polymer coating materials. 3,4,31 We are currently performing a series of mixed mode experimental tests to determine interface properties for polymer coatings on stainless steel substrates, allowing for the precise measurement of s max and r max .…”

Section: Discussionmentioning

confidence: 99%

“…Blends of PC are used on Medtronic and Abbott Vascular stent systems. Hyperelastic materials' behavior with properties being based on published stress-strain test data is assumed for Chronoflex, 3 SIBS, 4 and PU-GPC. 31 Strain rate-dependent data have not been published for these materials and are therefore not considered in this study.…”

Section: Finite-element Modelmentioning

confidence: 99%

Computational Investigation of the Delamination of Polymer Coatings During Stent Deployment

2010

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Recent advances in angioplasty have involved the application of polymer coatings to stent surfaces for purposes of drug delivery. Given the high levels of deformation developed in the plastic hinge of a stent during deployment, the achievement of an intact bond between the coating and the stent presents a significant mechanical challenge. Problems with coating delamination have been reported in recent experimental studies. In this paper, a cohesive zone model of the stent-coating interface is implemented in order to investigate coating debonding during stent deployment. Simulations reveal that coatings debond from the stent surface in tensile regions of the plastic hinge during deployment. The critical parameters governing the initiation of delamination include the coating thickness and stiffness, the interface strength between the coating and stent surface, and the curvature of the plastic hinge. The coating is also computed to debond from the stent surface in compressive regions of the plastic hinge by a buckling mechanism. Computed patterns of coating delamination correlate very closely with experimental images. This study provides insight into the critical factors governing coating delamination during stent deployment and offers a predictive framework that can be used to improve the design of coated stents.

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“…Reported tensile strength of this specific SIBS formulation, for example, ranges from 12.7 MPa to 17.7 MPa [13,31]. In the work by Lim et al, the use of nanofillers was investigated in order to improve mechanical properties of compression-molded SIBS, though no consideration was given to the effect of process parameters.…”

Section: Artificial Neural Networkmentioning

confidence: 97%

Improving tensile strength of an injection-molded biocompatible thermoplastic elastomer

et al. 2015

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Investigation of the rheological and mechanical properties of a polystyrene‐polyisobutylene‐polystyrene triblock copolymer and its blends with polystyrene

Cited by 34 publications

References 19 publications

Covalent Polyisobutylene–Paclitaxel Conjugates for Controlled Release from Potential Vascular Stent Coatings

Covalent Polyisobutylene–Paclitaxel Conjugates for Controlled Release from Potential Vascular Stent Coatings

Computational Investigation of the Delamination of Polymer Coatings During Stent Deployment

Improving tensile strength of an injection-molded biocompatible thermoplastic elastomer

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