Functionalized Silicone Elastomer via Alkaline Solution to Coat Phosphorylcholine-Based Copolymer Containing Organosilane to Improve Hemocompatibility for Medical Devices

Abstract

Surface modification of hemocompatible copolymers on silicone elastomers (SEs) is crucial for the long-term use of medical devices. Both physical adsorption and chemical conjugation are important for modification of SE. Oxygen plasma treatment is widely used to produce silanol groups on SE for silane coupling. However, the plasma reaction is difficult to apply to the surface modification of three-dimensional complex devices. This study demonstrated an appropriate and efficient method with alkaline solution for producing silanol groups on SE for modifying phosphorylcholine-based copolymer with organosilane (cross-MPC copolymer). A 2.5 wt% aqueous solution of potassium hydroxide (KOH) was effective in producing silanol groups and for coating the cross-MPC copolymer. Additionally, we successfully modified the cross-MPC copolymer on the inner surface of SE tubes after pretreatment with the 2.5 wt% KOH aqueous solution, and the copolymer film was coated homogeneously. The cross-MPC copolymer film on SE was stable for one month under fluidic condition with a shear stress of 3.2 Pa. The hollow fiber membrane with the polymer coating inhibited blood coagulation after one week implantation with extracorporeal circulation device using a goat. Therefore, pretreatment of SE using an alkaline solution is an appropriate method for producing silanol groups for coating the cross-MPC copolymer by silane-coupling reaction.

Development of a Membrane Oxygenator for Long-Term ECMO Support Using Fine Silicone Hollow Fiber

“…One method to address this issue is to substitute the methyl groups on the silicone surface with hydroxyl groups (-OH), which are hydrophilic, using oxygen plasma or excimer lamp treatment under vacuum [61,62]. Research has also been conducted on surface treatments using a polymeric material called 2-methacryloyloxyethylphosphorylcholine (MPC), which suppresses blood coagulation protein adsorption and denaturation with the aim of achieving longer-term durability [63][64][65]. SEC coating has been commercialized as a surface modification of composite membranes for oxygenator [66].…”

Antimicrobial Peptide Assembly on Zwitterionic Polymer Films to Slow Down Biofilm Formation

“…32,33 Owing to the covalent bonding between the substrates and cross-linked film structure, this polymer film has a strong stability in water flow and a hemocompatibility enough to use for medical devices. 34 Using an MPTMSi moiety, the polymer film was postmodified with a silane coupling agent containing an amino group (Figure 1B). The arrangement of the modified AMP was adjusted by using PEG spacers of different molecular weights and densities (Figure 1C).…”

“…In this study, we evaluated the antibacterial properties of an AMP-modified phospholipid zwitterionic polymer film by tuning the arrangement of the AMP for the efficient reduction of the biofilm. To provide the antibiofouling film, a biocompatible random copolymer consisting of MPC, 3-methacryloxypropyl trimethoxysilane (MPTMSi) as a silane coupling moiety, and 3-(methacryloyloxy) propyl-tris­(trimethylsilyloxy) silane (MPTSSi) as a hydrophobic adhesion moiety was selected (Figure A). , Owing to the covalent bonding between the substrates and cross-linked film structure, this polymer film has a strong stability in water flow and a hemocompatibility enough to use for medical devices . Using an MPTMSi moiety, the polymer film was postmodified with a silane coupling agent containing an amino group (Figure B).…”

Stability Enhancement by Hydrophobic Anchoring and a Cross-Linked Structure of a Phospholipid Copolymer Film for Medical Devices

“…To this end, material design for surface modification plays a pivotal role in stably modifying the coating polymers on the surface of the substrates. Because the protein-repellent polymers, including PEG and PMPC, as mentioned above are typically hydrophilic and soluble in water, the surface modification strategy for these polymers using physical adsorption and/or chemical bonding moieties is needed. ,− Among the methods using chemical bonding, polymer brushes with a dense and uniform structure formed by a “grafting-from” method exhibit superior antibiofouling properties; − while this approach includes the complex modification process, and application to the practical use is difficult. Physical adsorption facilitates the formation of coatings through an easy process.…”