Photopatterned Polymer Brushes Promoting Cell Adhesion Gradients

Abstract

The ability to spatially control cellular adhesion in a continuous manner on a biocompatible substrate is an important factor in designing new biomaterials for use in wound healing and tissue engineering applications. In this work, a novel method of engineering cell-adhesive RGD-ligand density gradients to control specific cell adhesion across a substrate is presented. Polymer brushes exhibiting spatially defined gradients in chain density are created and subsequently functionalized with RGD to create ligand density gradients capable of inducing cell adhesion on an otherwise weakly adhesive substrate. Cell studies indicate that these ligand-functionalized surfaces are noncytotoxic, with cellular adhesion increasing with RGD-ligand density across the gradient brush surface.

Swelling Behavior and Nanomechanical Properties of (Peptide-Modified) Poly(2-hydroxyethyl methacrylate) and Poly(poly(ethylene glycol) methacrylate) Brushes

“…The moduli measured for the PHEMA, PPEGMA 6 and PPEGMA 10 brushes studied here are in good agreement with those that have been reported for chemically crosslinked polyacrylamide 39 or zwitterionic carboxybetaine brushes. 40 Neutron reflectivity measurements were carried out at the ORNL Spallation Neutron Source.…”

“…The samples studied here were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-hydroxyethyl methacrylate (HEMA) as well as two poly(ethylene glycol) methacrylate monomers that differ with respect to the average number of side-chain ethylene glycol repeats, viz. PEGMA 6 and PEGMA 10 . These monomers were selected as they are widely used for the fabrication of model biointerfaces and combine excellent non-fouling properties with the presence of sidechain hydroxyl groups, which can be used to introduce biochemical cues via postpolymerization modification.…”

“…poly(2-(dimethylamino)ethyl methacrylate) 17,37 and PNIPAm 38 brushes, the swelling ratios were also found to decrease with increasing grafting density. The grafting density dependence of the swelling ratio decreases from PHEMA to PPEGMA 6 to PPEGMA 10 . The swelling ratios of the high grafting density brushes (σ = 100 %), which are reported in Table 1 and obtained by AFM are in good agreement with the ellipsometric data in Figure 4.…”

Polymer brushes and self-assembled monolayers: Versatile platforms to control cell adhesion to biomaterials (Review)

“…The potential to form two-dimensional gradients [155][156][157] and micron-scale patterns [158][159][160][161] of initiator-substituted adsorbates, together with control of the composition of the film by block copolymerization using a variety of polymerization methods [162][163][164] and monomers, affords a high level of control over the structure and functionality of polymer brushes, which allows for tailoring of the brushes for a wide variety of applications.…”

Controlled Release Strategies for Bone, Cartilage, and Osteochondral Engineering—Part II: Challenges on the Evolution from Single to Multiple Bioactive Factor Delivery

“…188 Many approaches have been used to fabricate scaffolds for osteochondral application by changing material composition, mechanical properties, and architecture between the chondrogenic and osteogenic layers. [172][173][174][188][189][190][191][192][193] Hierarchical scaffolds loaded with inductive factors disposed in two phases or even in gradients, capable of stimulating each layer toward the maturation of the specific tissue, are being increasingly explored. By using gradients of multiple bioactive factors, multiple tissue regeneration can be addressed via a single-cell source; that is, stem cells can differentiate along different lineages within the same constructs.…”