Synthesis of peptide-polymer conjugates and fabrication of multicomponent protein nanoarrays

Conjugation of biocompatible polymers to proteins is becoming a common approach to generate therapeutics with improved pharmacokinetic properties. These conjugates are widely used in biotechnology and nanotechnology. Chapter 1 describes conventional approaches to prepare well-defined polymer conjugates. Recently developed techniques describing the use of macroinitiators as well as preparation of homo and heterodimeric conjugates is also described. Methods to immobilize proteins on surfaces via oxime chemistry are also described.;A synthetic strategy to prepare peptide-polymer conjugates with site-specific attachment is described in Chapter 2. An amino acid based atom transfer radical polymerization (ATRP) initiator for the polymerization of methacrylates is presented.;This initiator was employed in the ATRP of 2-hydroxyethyl methacrylate (HEMA), HEMA modified with N-acetyl-D-glucosamine (GlcNAc), and 3-3'-diethoxypropyl methacrylate (DEPMA). The deprotected amino acid was incorporated into VM(S*)VVQTK by standard solid phase peptide synthesis and glycopolymer-peptide conjugates were prepared.;Immobilizing proteins in specific orientations is important for diagnostic protein arrays, biomaterials, and other applications where retention of bioactivity is essential. Chapter 3 describes an approach for protein micropatterning that exploits a chemoselective reaction to conjugate proteins at the N-terminus to polymer films. Local deprotection of protein reactive groups was achieved by photoacid generator-based photolithography. Conjugation of alpha-ketoamide modified streptavidin via oxime bond formation was demonstrated.;The remaining chapters involve precise orientation of multiple proteins at the nanoscale. Smaller feature sizes correlate to higher sensitivities in diagnostics and are critical for controlling receptor-mediated cellular responses for biomaterials. Chapters 4 and 5 describe a method to construct nanoscale patterns of more than one protein: side by side or in multilayer formats. Electron-beam-induced cross-linking of poly(ethylene glycol) (PEG) polymers with end-groups that bind to specific sites on proteins produced reactive nanoarrays. By patterning multiple PEGs of orthogonal functionality, simultaneous binding of more than one protein from a mixture was achieved in aqueous solution without the addition of other reagents. Finally, in Chapter 6 electron-beam lithography is used create patterns of the peptide RGD, a cell adhesion ligand involved in integrin binding. These patterns are demonstrated to adhere fibroblast cells, and may be useful in directing differentiation of stem cells into fibroblasts.