Group reorientation and migration of amphiphilic polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking coating

Abstract

Amphiphilic polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-polymer coating. When the polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the polymer coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials.

Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

“…Phosphorylcholine (PC) is a kind of highly hydrophilic and zwitterionic head group present in the outer surface of the erythrocyte bilayer in the cell membrane. The construction of cell outer membrane mimetic surfaces by incorporating PC moieties onto the exterior surface of biomaterials has proved to be an effective method to suppress the undesirable interactions with biomolecules and improve the blood compatibility of materials [9,[14][15][16][17][18][19][20][21][22][23][24][25][26]. It generally attributes to the formation of a bound hydration layer and the presence of zwitterionic structures on the exterior surfaces, which are found beneficial to maintain the normal conformation of biomolecules [16].…”

“…The typical approaches attempted to integrate PC-containing substances onto the biomaterial surfaces have mainly concentrated on the physical adsorption and chemical grafting methods [9,[14][15][16][17][18][19][20][21][22][23][24][25][26]. In comparison with physical adsorption method, the covalent attachment of PC-containing substance is generally achieved through the specific chemical reaction with the functionalized material surfaces, which often overcome the poor interfacial adhesive force with substrate in aqueous media and ensure the long-term stability [20][21][22][23][24][25][26].…”

Long circulating micelles of an amphiphilic random copolymer bearing cell outer membrane phosphorylcholine zwitterions

“…The hydrophilic PC groups of the polymer can reorient to the interface in aqueous environment forming a cell outer membrane mimetic structure [38][39][40]. The closely packed zwitterionic PC groups bind hydration water strongly through electrostatic interactions [41] and suppress non-specific protein adsorption and foreign body reactions [42][43][44][45].…”

Phosphorylcholine-Modified Chitosan Films as Effective Promoters of Cell Aggregation: Correlation Between the Films Properties and Cellular Response

“…This result is important, as PC groups must be exposed on the film/water interface in order to act as nonfouling groups. The migration of PC groups towards the film/water interface has been reported previously . The thickness ( d ) of the films, estimated from QCM‐D data using 1037 ± 2 g · dm −3 as the average film density [Equation (SI 3)] increases from ≈4 nm for CH films to ≈15 nm for CH‐PC40.…”