Cell Surface-based Polymer Conjugation Service

Cell surface modification technology, an emerging research area, will be applied to the treatment of patients in the areas of regenerative medicine, tissue engineering, stem cell research, and embryology. Focusing on cell membrane engineering services over years, Creative Biolabs has accumulated extensive experience. With professional experience and strong foundations, we are confident in providing reliable cell surface-based polymer conjugation service.

Introduction of Cell Surface-based Polymer Conjugation

Cell surface modification can be used to study cell-cell interactions and to control stem cell lineages in regenerative medicine. Surface modification of living cells with natural and synthetic polymers allows for new opportunities in biomedical engineering and science. A variety of functional groups and bioactive substances have been introduced onto the cell surface. The three methods generally employed in cell surface modification are covalent conjugation, hydrophobic interaction, and electrostatic interaction.

Fig.1 Cell surface modification with synthetic polymers. (Teramura, 2010)

Methods

• Covalent conjugation to amino groups of cell surface proteins

For covalent conjugation of polymers, surface modification of living cells has been achieved through chemical or enzymatic treatment or by metabolic introduction. The N-hydroxyl-succinimidyl ester (NHS) group and cyanuric chloride are frequently used to chemically form covalent bonds to amino groups of membrane proteins. There is a potential that toxic effects are exerted on membrane proteins. Enzymatic treatment and metabolic introduction have also been employed to add various functional groups such as biotin, azide, and ketone groups to living cell surfaces. The technologies are limited to the introduction of specified functional small molecules to cells and might perturb cell physiology. Although covalent immobilization was expected to be stable for chemical degradation and present for a long period because of covalent bonding to membrane proteins, introduced polymers and functional groups disappeared from the cell surface with time.

• Incorporation of amphiphilic polymers into the lipid bilayer membrane of cells by hydrophobic interaction

Amphiphilic polymers such as PEG-conjugated phospholipids (PEG-lipid) and poly (vinyl alcohol) bearing hydrophobic alkyl side chains (PVA-alkyl) have been used for cell surface modification. In this method, hydrophobic alkyl chains of amphiphilic polymers are spontaneously anchored into the lipid bilayer membranes through the hydrophobic interaction. This spontaneous incorporation was monitored by a surface plasmon resonance (SPR) instrument when a PEG-lipid solution was applied onto the supported lipid membrane formed on an SPR sensor surface. The spontaneous incorporation of PEG-lipid was observed and it is greatly affected by the length of alkyl chains of the phospholipids, that is, their hydrophobicity.

• Electrostatic interaction between cationic polymers and a negatively charged surface

It has been explored that the possibility of constructing thin polymer membranes on the surface of cells through electrostatic interactions between negatively charged cell surfaces and cationic polymers and then further modified using a layer-by-layer technique of anionic and cationic polymers. Ionic polymers that have been employed are poly- (allylamine hydrochloride), poly(styrene) sulfate, poly-L-lysine (PLL), and poly(ethyleneimine) (PEI). A layer-by-layer method is a simple and attractive method to modify the cell surface. The surface property can be controlled by the outermost layer of the polymer. The thickness of the membrane is also controllable by the number of applications of the polymer solution. Unfortunately, most polycations, such as PLL and PEI were found to be extremely cytotoxic and severely damaged treated cells. PEI which interacted with cells was not degraded and not excluded from the cell because PEI immediately destroyed the cell membrane after interaction with the cell surface.

Services at Creative Biolabs

With years of practice in the research of cell membrane engineering services, Creative Biolabs is professional in this field. We have developed a comprehensive technology platform with strong foundations and excellent scientific staff. With advantages in various aspects, we are confident in providing high-quality cell surface-based polymer conjugation services.

With rich experience and strong foundations, Creative Biolabs aspires to bring every client satisfying cell membrane engineering services with top-rated customer experience. If you are interested in cell surface-based polymer conjugation services or other cell surface conjugation services, please don't hesitate to contact us for more information.

Reference

1. Teramura, Y.; Iwata, H. Cell surface modification with polymers for biomedical studies. Soft Matter. 2010, 6(6): 1081-1091.