Directional Migration of Vascular Smooth Muscle Cells Guided by a Molecule Weight Gradient of Poly(2-hydroxyethyl methacrylate) Brushes

Abstract

Directional migration of cells mediated by gradient cues in vitro can mimic the corresponding biological events in vivo and thereby provides a way to disclose the cascade responses in tissue regeneration processes and to develop novel criteria for design of tissue-inductive biomaterials. In this work, a molecular weight gradient of poly(2-hydroxyethyl methacrylate) (PHEMA) brushes with a thickness ranging from 3 to 30 nm and slopes of 0.8-3.2 nm/mm were fabricated by using surface-initiated atom transfer radical polymerization (ATRP) and a dynamically controlled reaction process. The PHEMA gradients were characterized by X-ray photoelectron spectrometry (XPS) and ellipsometry. The adhesion number, spreading area, adhesion force, and expression of focal adhesion and actin fibers of vascular smooth muscle cells (VSMCs) decreased along with the increase of the PHEMA brushes length. The VSMCs exhibited preferential orientation and enhanced directional migration toward the direction of reduced PHEMA thickness, whose extent was dependent on the gradient slope and polymer thickness. Most of the cells were oriented, and 87% of the cells moved directionally at the optimal conditions.

A complementary density gradient of zwitterionic polymer brushes and NCAM peptides for selectively controlling directional migration of Schwann cells

“…Previous studies reveal that the cell adhesion force on substrate plays an important role on cell migration behavior [17,18]. Cells usually have the highest mobility on the surfaces with a moderate adhesion force, i.e.…”

“…For example, by adjusting the cell adhesion force on the substrates, the cell migration rate can be modulated by the grafting amount of poly(ethylene glycol) (PEG) [17], the brush length of poly(hydroxyethyl methacrylate) (PHEMA) [18], and the stiffness of salt-treated multilayers [19]. Because all these methods adjusted surface wettability and thus changed cellesubstrate interaction [20].…”

Regulation of the migration of endothelial cells by a gradient density of vascular endothelial growth factor

“…After culture for 12 h, the cells migrations were monitored using a live cell station equipped with an incubation chamber (37 • C and 5% CO 2 humidified atmosphere) and a time-lapse digital camera [29]. Images for cell migration were taken every 15 min within 6.5 h. The ECs trajectories were reconstructed according to the center positions of individual cell over the observation period.…”

In situ-preparation and characterization of silver-HEMA/PEGDA hydrogel matrix nanocomposites: Silver inclusion studies into hydrogel matrix

“…Neutral synthetic polymers can be generated from derivatives of poly(hydroxyethyl methacrylate) (PHEMA), poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVA) (Ren et al, 2013;Tockary et al, 2013). Hydrogels based on PHEMA and PEG are the most widely studied materials and, also, the most used for biomedical applications due to their non-toxicity and non-immunogenic properties, making these types of hydrogels approved by the US Food and Drug Administration for a wide variety of medical uses such as human intravenous injection and oral and dermal applications .…”