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Improved hemocompatibility of poly(ethylene terephthalate) modified with various thiol-containing groups
Heather Gappa-Fahlenkamp1, Randy S Lewis
1School of Chemical Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
Biomaterials
|December 29, 2004
Summary
Researchers modified polyethylene terephthalate (PET) with thiol groups to release nitric oxide (NO), effectively reducing platelet adhesion in blood and plasma. L-cysteine modification showed the most significant anti-adhesion effect.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Biomedical Engineering
Background:
- Platelet adhesion to biomaterials is a major cause of medical device failure.
- Nitric oxide (NO) is a known inhibitor of platelet aggregation.
- Developing materials that can release NO is crucial for improving blood-contacting devices.
Purpose of the Study:
- To functionalize polyethylene terephthalate (PET) with thiol groups for nitric oxide (NO) immobilization and release.
- To optimize the attachment of different thiol-containing groups (L-cysteine, 2-iminothiolane, cysteine polypeptide) onto PET.
- To evaluate the efficacy of NO-releasing PET in preventing platelet adhesion in vitro.
Main Methods:
- Modification of PET with three different thiol-containing groups: L-cysteine, 2-iminothiolane, and a cysteine polypeptide.
- Optimization of processing parameters to maximize thiol immobilization on the PET surface.
- Quantification of immobilized thiol concentrations.
- In vitro assessment of platelet adhesion using a parallel plate perfusion chamber with various biological solutions (Tyrode's buffer, nitrosated bovine serum albumin, plasma, whole blood).
Main Results:
- Immobilized thiol concentrations increased in the order: cysteine polypeptide < 2-iminothiolane < L-cysteine.
- All modified PET polymers significantly reduced platelet adhesion compared to controls in plasma and whole blood solutions.
- The L-cysteine modified PET demonstrated the most substantial reduction in platelet adhesion (65%) when tested with plasma.
Conclusions:
- Surface modification of PET with thiols enables effective immobilization and subsequent release of nitric oxide (NO).
- L-cysteine functionalization of PET provides superior anti-platelet adhesion properties compared to other tested thiol groups.
- These NO-releasing PET biomaterials hold promise for developing improved blood-contacting medical devices with reduced thrombogenicity.