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Spatially arrayed, high-density microarrays enable the rapid assessment of biological recognition events, and this information is of widespread interest for those working in basic research laboratories as well as in the clinic. Today, one can find DNA, protein, or small molecule arrays. Limitations with these systems include covalent modification of the target complement to the array substrate, array- and target-dependent setup conditions, multiple steps, and loss of hydration at the surface. To overcome these limitations, we have designed, prepared, and evaluated immobilized hydrogels as general screening chambers for small molecule-protein, protein-protein, and nucleic acid-nucleic acid interactions. This biomaterial-based approach is facile, rapid, requires only one setup protocol, and physically entraps the target complement within the polymer network and thus offers advantages over the conventional chips.

An efficient and general synthetic strategy is described for preparing high-molecular-weight hydrophilic polymers bearing both carboxylic acid and hydroxyl pendant groups. Poly(5,6-dihydroxyoxanorbornane carboxylic acid) is prepared by ring-opening metathesis polymerization of methyl 5-oxanorbornene-2-carboxylate in the presence of Grubbs catalyst II and is modified to tune the hydrophobic/hydrophilic properties by introducing either hydroxyl or carboxylic acid functionalities.

New uridine and adenosine phosphocholine amphiphiles are prepared. The dynamics of the recognition and supramolecular assembly formation is visualized in real time at the micrometer scale and is dependent on the nucleobase complementary recognition and the hydrophobic ketal chains.

A geminal phosphonium dication is synthesized and subsequently coordinated with mono-, di- and tetraanions. The strategy using multicationic and multianionic molecules has helped in preparing new supramolecular ionic networks with properties not attainable with current ionic liquids.

The synthesis of peptide dendrons, the formation of cross-linked hydrogels, the analysis of hydrogel physical properties, and the use of these biomaterials to seal a corneal incision are reported. A new in situ polymerizing hydrogel is reported that gels within a few minutes from the multiple thiazolidine linkages formed between the cysteine residues of the dendron and the poly(ethylene glycol) macromers.

A large-molecular-weight polyanion is found to possess lubricating properties for cartilage. The polyanion, sodium poly(7-oxanorbornene-2-carboxylate), is synthesized by ring-opening metathesis polymerization of methyl 5-oxanorbornene-2-carboxylate. When dissolved in aqueous solution and applied to the surface of human cartilage it reduces the friction at the interface and acts as a lubricant. Its performance is similar to that of synovial fluid and superior to those of saline and Synvisc in an ex vivo human cartilage plug-on-plug model. The polymer is also not readily degraded by hyaluronidase or cytotoxic to human chondrocytes in vitro. As such, this polymer is a new type of viscosupplement, and the results provide insight into the design requirements for synthesizing highly efficacious synthetic biolubricants. [ABSTRACT FROM AUTHOR]

In pursuit of a wound-specific corneal adhesive, hydrogels formed by the reaction of propionaldehyde, butyraldehyde, or 2-oxoethyl succinate-functionalized poly(ethylene glycol) (PEG) with a peptide-based dendritic cross-linker (Lys(3)Cys(4)) were characterized. These macromers react within minutes of mixing to form transparent and elastic hydrogels with in vitro degradation times that range from hours to months based on the type of bonds formed during the cross-linking reaction, either thiazolidine or pseudoproline. The mechanical properties of these materials, determined via parallel plate rheology, were dependent on the polymer concentration, as was the hydrogel adhesive strength, which was determined by lap shear adhesive testing. In addition, these hydrogels were efficacious in closing ex vivo 4.1 mm central corneal lacerations: wounds closed with these hydrogel adhesives were able to withstand intraocular pressure values equivalent to, or in excess of, those obtained by closing the wounds with suturing.

A stable cross-linked hydrogel was formed under mild aqueous conditions using pseudoproline peptide ligation chemistry. A cysteine-terminated lysine dendron containing four cysteines and a PEG macromolecule modified with terminal ester aldehydes were prepared. Upon mixing, the two macromers gave a stable hydrogel. This hydrogel along with sutures was used to successfully secure a corneal transplant in vitro.