In vitro and in vivo hemocompatibility assessment of ultrathin sulfobetaine polymer coatings for silicon-based implants

Abstract

Highly uniform silicon nanopore membranes were developed for applications in implantable bioartificial organs. A robust, readily scalable, non-fouling surface coating is required to enhance silicon nanopore membrane hemocompatibility. However, the coating must be ultrathin to keep the nanopores from occluding. Recently, zwitterionic brush polymers have demonstrated significantly lower fouling under biological conditions. In this study, we explore ultrathin zwitterionic poly(sulfobetaine methacrylate) (pSBMA) surface coating at sub-5 nm thickness. Membrane hydraulic permeability was measured before and after surface modification of silicon nanopore membranes, and pores were found to be patent and in agreement with coating thickness measurements. Coating stability was analyzed under biological shear as well as under blood flow in vitro and in vivo. Following exposure to shear over 24 h, coatings were characterized via X-ray photoelectron spectroscopy, goniometry, and ellipsometry, and found to survive biological shear. In vitro blood experiments with fresh human blood as well as in vivo 7-day and 26-day implants in a porcine model demonstrate minimal platelet adhesion and activation with pSBMA surface modification compared to unmodified silicon exposed to fresh human blood in vitro. These results demonstrate that ultrathin pSBMA surface modification is a viable choice for application in blood contacting implants with critical nanoscale features.

Infection Resistant Surface Coatings by Polymer Brushes: Strategies to Construct and Applications

“…The coated SNMs showed promising attributes and can be potentially considered as bioartificial kidney, an implant for pancreas, and so on. An in vivo study in which implants were inserted in a porcine model for 7 and 26 days was carried out to demonstrate minimal platelet adhesion on a pSBMA brush modified surface as compared to the unmodified surface of silicon . Similarly, immobilization of zwitterionic brushes on spherical mesoporous silica nanoparticles was also reported.…”

“…An in vivo study in which implants were inserted in a porcine model for 7 and 26 days was carried out to demonstrate minimal platelet adhesion on a pSBMA brush modified surface as compared to the unmodified surface of silicon. 153 Similarly, immobilization of zwitterionic brushes on spherical mesoporous silica nanoparticles was also reported. These antifouling poly(sulfobetaine methylacrylate) brushes were grafted on the surface of core− shell mesoporous silica nanoparticles via SI-ATRP.…”

Improvement in the Microbial Resistance of Resin-Based Dental Sealant by Sulfobetaine Methacrylate Incorporation

“…Among zwitterionic compounds with antifouling properties, sulfobetaine methacrylate (SB) has often been studied due to its ease of production and use [12]. Diverse biomedical applications of SB as a non-fouling agent in sensors and membrane coatings have been reported [13,14]. Moreover, dental cements and resin-based composites containing zwitterions, including methacryloyloxyethyl phosphorylcholine (MPC) and dimethylaminohexadecyl methacrylate (DMAHDM), have recently been reported.…”

Biomedical Uses of Sulfobetaine-Based Zwitterionic Materials

“…Indeed, the recent increase in exploration of SB-based materials for in vivo evaluations brings their clinical use closer to reality. 213,214 Beyond surface uses, there are a variety of promising directions for SB-based zwitterion biomaterials in applications such as wound healing or insulin administration, which may be ripe for translation in future years. 136,215 Many of the possible applications for which the antifouling properties of SB would prove beneficial remain to be explored.…”