Functionalized porous substrate for binding chemical and biological moieties

#The invention relates to porous polymeric materials to which chemical or biological moieties have been attached, and methods for making the same.

#Porous polymeric materials can be used in a variety of applications. Their uses include medical devices that serve as substitute blood vessels, synthetic and intraocular lenses, electrodes, catheters, and extracorporeal devices such as those that are connected to the body to assist in surgery or dialysis. Porous polymeric materials can also be used as filters for the separation of blood into component blood cells and plasma, microfilters for removal of microorganisms from blood, and coatings for opthalmic lenses to prevent endothelial damage upon implantation.

#Bonding materials other than polymers to porous polymeric materials can alter the properties of porous polymers. A combination of properties may provide porous polymers suitable for the above mentioned purposes. This combination, however, has been difficult to achieve because of the natural properties of polymers.

#Various aspects of the invention are understood with reference to the following figures:

#FIG. 1 represents a side view of a material of the invention, wherein regions of a functional additive are embedded within a porous plastic substrate;

#FIG. 2 provides a representation of the attachment of spacers of varying lengths to a porous substrate, followed by the attachment of chemical or biological moieties to those spacers;

#Many plastics do not contain reactive functional groups (e.g. hydroxyl or amine groups) that can be used to attach chemical or biological moieties to surfaces of materials made from them. The surfaces of such materials can therefore be difficult to modify. This invention is based on a discovery that the surface properties of porous plastic materials can be altered in a controllable fashion by incorporating varying amounts of functional additives into those materials. Functional additives are materials that contain functional groups to which biological and/or chemical moieties can be covalently attached.

#FIG. 1 depicts various aspects of materials of the invention. In particular, it provides a representation of a porous substrate made of a plastic and a functional additive. Portions of the functional additive that are exposed on the surface of the substrate provide functional groups (represented in FIG. 1 as “Fn”) to which chemical or biological moieties (represented by “CBM”) can be covalently bound. Alternatively, a spacer can connect a chemical or biological moiety to the surface. Preferably, the plastic that surrounds the regions of functional additives contains few, if any, functional groups. Alternatively, the plastic may contain functional groups that are less reactive under certain reaction conditions than the functional groups of the functional additive, such that chemical or biological moieties can be bound primarily to exclusively to regions of functional additive.

#As discussed elsewhere herein, the polymer (e.g., plastic) from which the porous substrate is made is selected to provide a substrate of desired strength, flexibility, porosity, and resistance to degradation. Other factors, such as cost and biocompatibility may also play a role in its selection. The chemical or biological moiety(ies) bound to the substrate are selected to provide a final material with desired chemical and/or physical properties, while the type and amount of functional additive(s) are selected to affect the number and/or density of chemical or biological moieties bound to the substrate. For example, the chemical reactivity of functional groups provided by the functional additive can affect the number of moieties attached to the substrate surface.