Routes to Bioactive Hydrophilic Polymers

Bamford, C. H.; Middleton, I. P.; Al-Lameé, Kadem; Paprotny, J.; Satake, Yoshikatsu

doi:10.1295/polymj.19.475

Cited by 24 publications

(38 citation statements)

References 7 publications

(5 reference statements)

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“…These side-chains behave as spacers separating the bioactive units from the polymer backbonesthe spacer length is often an important feature influencing bioactivity in such systems. The spacer may be hydrophilic (CH 2CH 2 0 )n or hydrophobic (CH 2CH 2 )m' We have found significant effects on the molar activity of coupled BW 245C produced by variations in spacer length and hydrophilicity in polymers based on N-vinyl pyrrolidone (R = ot:J ) studied in aqueous solution (11,14).…”

Section: Antiplatelet Agentsmentioning

confidence: 96%

“…A relevant example is the vasodilator dipyridamole (Persantin, Boehringer, Mannheim, Germany) [10) which may be esterified with methacrylic acid to yield the monomer [11) (DIMA). This ester provides a useful method for coupling dipyridamole to polymers.…”

Section: Antiplatelet Agentsmentioning

confidence: 99%

“…This ester provides a useful method for coupling dipyridamole to polymers. After derivatization of [10) the monoester [11) was purified by TLC to ensure the absence of higher esters which could subsequently lead to crosslinking.…”

Section: Antiplatelet Agentsmentioning

confidence: 99%

“…R=Ph) to yield the polymer-BW 245C adduct shown in [6). This represents a portion of the polymer chain; the proportions of BW 245C and vinyl monomer units are [5) [12] to the urethane linkages and used as free radical sources (with the aid of the metal carbonyl processes already outlined) (18,19) to graft on the BW 245C-monomer ( [5], n=1) and DI MA [11] and many other species. Interesting monomers [14], [15], have been prepared from several a-amino acids and also from amino sugars, e.g.…”

Section: Antiplatelet Agentsmentioning

confidence: 99%

“…2a). Figure 2b shows the effect of grafting DIMA [11] to Biomer with the aid of the halogenation route in Scheme 2. Evidently a low proportion of dipyridamole is very effective in reducing platelet adhesion to Biomer.…”

Section: Platelet Adhesionmentioning

confidence: 99%

See 4 more Smart Citations

Modification of Biomaterials to Improve Blood Compatibility

et al. 1992

Int J Artif Organs

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Section: Antiplatelet Agentsmentioning

confidence: 96%

Section: Antiplatelet Agentsmentioning

confidence: 99%

Section: Antiplatelet Agentsmentioning

confidence: 99%

Section: Antiplatelet Agentsmentioning

confidence: 99%

Section: Platelet Adhesionmentioning

confidence: 99%

See 3 more Smart Citations

Modification of Biomaterials to Improve Blood Compatibility

et al. 1992

Int J Artif Organs

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Studies on a new strategy for surface modification of polymeric biomaterials

Aldenhoff

Koole

1995

J. Biomed. Mater. Res.

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A new methodology to improve the hemocompatibility of polyurethane (medical grade Pellethane D-55) surfaces is reported. The approach is essentially based on a photochemical immobilization reaction. Two new conjugate molecules, compounds 2 and 3, were prepared. They consist of (i) dipyridamole, a well-known inhibitor of platelet activation, and a vasodilating drug with clinical application, for instance before and during pecutaneous transluminar coronary angioplasty (Dottering); and (ii) an aryl azide, a moiety that exhibits marked photoreactivity. In 2, the dipyridamole unit is directly linked to the aryl azide (via an ester bond), while a short spacer chain separates both units in 3. Upon irradiation of 2 or 3, adsorbed onto the polyurethane foil, the aryl azide is converted into a highly reactive species which reacts with a nucleophilic group on the polymer surface. In this way, the dipyridamole is covalently linked to the polymer. The underlying principle is also used in photoaffinity labeling, a well-known technique in biochemical studies on enzyme structure and function. From UV extinction experiments it could be deduced that the surface-density of immobilized 2 is 4.9 nmol/cm2. The surface density for 3 was 14.6 nmol/cm2. The surfaces were subjected to an in vitro thrombin generation assay. This assay gives a valuable impression about the hemocompatibility of artificial surfaces. These experiments revealed that the clotting times were substantially prolonged as a result of the photoimmobilization of dipyridamole. This was especially the case for immobilized 3. This effect cannot be readily explained. Possibly, the enhanced activity of immobilized 3 is due to the spacer chain. An alternative explanation is that the surface density is larger for 3 than for 2. In addition, the photomodified surfaces were incubated with platelet-rich blood plasma (37 degrees C, 30 min) and subsequently examined by scanning electron microscopy. The morphology of the blood platelets adhered to the surface also showed that hemocompatibility increased in the order untreated polyurethane < polyurethane with immobilized 2 < polyurethane with immobilized 3. Future work will concentrate on evaluation of the role of the spacer (length, hydrophilicity, etc.), as well as on the possible use of this approach with respect to the construction of biomaterials with improved in vivo biocompatibility, in particular hemocompatibility.

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Macromolecular design and application using Mn₂(CO)₁₀‐based visible light photoinitiating systems

Çiftçi

Taşdelen

Yaǧcı

2016

Polymer International

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The environmentally friendly Mn 2 (CO) 10 -based visible light photoinitiating system is a powerful method for the preparation of linear and crosslinked polymeric structures. From a practical point of view, the most important feature of this initiating system is its optical characteristics in the visible range with high quantum yield and good solubility properties. This photoinitiating system is applicable for a variety of monomers that can be polymerized via either radical or cationic mechanisms. Various complex macromolecular structures such as telechelic polymers, block and graft copolymers, polymer networks and surface modifications can be simply prepared by using halogenated precursors. This photoinitiating system is also combined with controlled radical polymerization techniques providing a mild and efficient method for polymer synthesis.

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Routes to Bioactive Hydrophilic Polymers

Cited by 24 publications

References 7 publications

Modification of Biomaterials to Improve Blood Compatibility

Modification of Biomaterials to Improve Blood Compatibility

Studies on a new strategy for surface modification of polymeric biomaterials

Macromolecular design and application using Mn₂(CO)₁₀‐based visible light photoinitiating systems

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Routes to Bioactive Hydrophilic Polymers

Cited by 24 publications

References 7 publications

Modification of Biomaterials to Improve Blood Compatibility

Modification of Biomaterials to Improve Blood Compatibility

Studies on a new strategy for surface modification of polymeric biomaterials

Macromolecular design and application using Mn2(CO)10‐based visible light photoinitiating systems

Contact Info

Product

Resources

About

Macromolecular design and application using Mn₂(CO)₁₀‐based visible light photoinitiating systems