MPC Polymer Research Articles

Antithrombotic Revascularization Strategy of Bioengineered Liver Using a Biomimetic Polymer.

A bioengineered liver has the potential to save patients with end-stage liver disease, and a three-dimensional decellularized scaffold is a promising approach for practical use. The main challenge in bioengineered liver transplantation is thrombogenicity during blood perfusion. We aimed to apply a novel antithrombotic polymer to revascularize liver scaffolds and evaluate the thrombogenicity and biosafety of the polymer-treated scaffolds. A biomimetic polymer, 2-metacryloyloxyethyl phosphorylcholine (MPC) was prepared for modification of the extracellular matrix in liver scaffolds. The polymer was injected into the rat liver scaffolds' portal vein and could extensively react to the vessel walls. In an ex vivo blood perfusion experiment, we demonstrated significantly less platelet deposition in the polymer-treated scaffolds than nontreated or re-endothelialized scaffolds with human umbilical vein endothelial cells. In the heterotopic transplantation model, liver volume was better maintained in the polymer-treated groups, and platelet deposition was suppressed in these groups. Additionally, the polymer-treated liver scaffolds maintained the metabolic function of the recellularized rat primary hepatocytes during perfusion culture. The MPC polymer treatment efficiently suppressed thrombus formation during blood perfusion in liver scaffolds and maintained the function of recellularized hepatocytes. Revascularizing liver scaffolds using this polymer is a promising approach for bioengineered liver transplantation.

Stable and Thin-Polymer-Based Modification of Neurovascular Stents with 2-Methacryloyloxyethyl Phosphorylcholine Polymer for Antithrombogenicity.

The advent of intracranial stents has revolutionized the endovascular treatment of cerebral aneurysms. The utilization of stents has rendered numerous cerebral aneurysm amenable to endovascular treatment, thereby obviating the need for otherwise invasive open surgical options. Stent placement has become a mainstream approach because of its safety and efficacy. However, further improvements are required for clinically approved devices to avoid the frequent occurrence of thrombotic complications. Therefore, controlling the thrombotic complications associated with the use of devices is of significant importance. Our group has developed a unique stent coated with a 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer. In this study, the surface characteristics of the polymer coating were verified using X-ray photoelectron spectroscopy and atomic force microscopy. Subsequently, the antithrombotic properties of the coating were evaluated by measuring platelet count and thrombin-antithrombin complex levels of whole human blood after 3 h of incubation in a Chandler loop model. Scanning electron microscopy was utilized to examine thrombus formation on the stent surface. We observed that MPC polymer-coated stents significantly reduced thrombus formation as compared to bare stents and several clinically approved devices. Finally, the coated stents were further analyzed by implanting them in the internal thoracic arteries of pigs. Angiographic imaging and histopathological examinations that were performed one week after implantation revealed that the vascular lumen was well maintained and coated stents were integrated within the vascular endothelium without inducing adverse effects. Thus, we demonstrated the efficacy of MPC polymer coating as a viable strategy for avoiding the thrombotic risks associated with neurovascular stents.

Thermodynamics of interactions and structural peculiarities of interpenetrating polymer networks based on polyurethane and copolymer of 2-hydroxyethyl methacrylate with methacryloyloxyethylphosphorylcholine

Interpenetrating polymer networks based on biocompatible components – polyurethane and copolymer of 2-hydroxyethyl methacrylate with methacryloyloxyethylyphosphorylcholine (HEMA-MPC) were synthesized and thermodynamic parameters of interactions in the system and morphology were investigated. The thermodynamic parameters of interactions between polymer components of the IPNs were calculated based on sorption isotherms of methylene chloride vapors by samples of the created polymer systems. It is shown that MPC plays the role of a compatibilizer in the system, increasing the thermodynamic compatibility between polyurethane and the HEMA-MPC copolymer at small amounts of the copolymer in the IPNs. As the amount of copolymer HEMA-MPC in the IPNs increases, the value of the free energy of the polyurethane and copolymer mixing shifts to the positive value, which is associated with the formation of ionic clusters of MPC. This may mean that with an increasing amount of the MPC in the system, interactions between the negatively charged phosphoryl groups and the positively charged nitrogen atom of various MPC polymer chains occur, i.e., the part of intermolecular interactions (polyurethane and copolymer) decreases, while the part of intramolecular interactions (between different groups of MPC) increases. The results of the morphology investigations of the IPN samples are consistent with the data of the thermodynamic compatibility study of polymers during the formation of the IPNs. With a significant increase in the positive values of the free energy of the polyurethane and copolymer mixing in the IPNs with 41 % and 51 % of the copolymer content, a significant phase separation is observed in the IPNs, with phase inclusions ranging from 1 to 5 mm.

Preparation and Characterization of Acrylic and Methacrylic Phospholipid-Mimetic Polymer Hydrogels and Their Applications in Optical Tissue Clearing.

The 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers are mimetic to phospholipids, being widely used as biocompatible polymers. In our previous study, MPC polymer hydrogels proved more effective for optical tissue clearing compared to acrylamide (AAm) polymer hydrogels. In the present study, 2-acryloyloxyethyl phosphorylcholine (APC) was synthesized and employed to create hydrogels for a comparative analysis with methacrylic MPC-based hydrogels. APC, an acrylic monomer, was copolymerized with AAm in a similar reactivity. In contrast, MPC, as a methacrylic monomer, demonstrated higher copolymerization reactivity than AAm, leading to a spontaneously delayed two-step polymerization behavior. This suggests that the polymer sequences and network structures became heterogeneous when both methacrylic and acrylic monomers, as well as crosslinkers, were present in the copolymerization system. The molecular weight of the APC polymers was considerably smaller than that of the MPC polymers due to the formation of mid-chain radicals and subsequent β-scission during polymerization. The swelling ratios in water and strain sweep profiles of hydrogels prepared using acrylic and methacrylic compounds differed from those of hydrogels prepared using only acrylic compounds. This implies that copolymerization reactivity influences the polymer network structures and crosslinking density in addition to the copolymer composition. APC-based hydrogels are effective for the optical clearing of tumor tissues and are applicable to both passive and electrophoretic methods.

Biomimetic affinity membrane roll column for rapid purification of C-reactive protein

To in-depth explore the action mechanism of C-reactive protein (CRP) and precisely study its signaling pathways, it is essential to acquire high-purity CRP while preserving its intact structure and functionality. In this study, we propose and fabricate a high-density 2-methacryloyloxyethyl phosphorylcholine (MPC)-modified membrane roll column (MPC-MRC) using a surface-initiated atom transfer radical polymerization (SI-ATRP) approach, which can overcome these limitations (long incubation time and low adsorption capacity) of conventional enrichment materials. The MPC-MRC incorporates a high-density 2-hydroxyethyl methacrylate polymer brush to prevent non-specific protein adsorption and multiple MPC polymer brush layers for high-performance enrichment of CRP in the company of calcium ions. Furthermore, the MPC-MRC exhibits high permeability, hydrophilicity, and mechanical strength. Compared to previous technologies, this novel material demonstrates significantly higher CRP binding capacity (310.3 mg/g), shorter processing time (only 15 min), and lower cost (only 12 USD/column). Notably, the MPC-MRC enables fast and effective purification of CRP from both human and rat serum, exhibiting good selectivity, recovery (> 91.3 %), and purity (> 95.2 %). Thus, this proposed purification approach based on MPC-MRC holds great potential for target protein enrichment from complex samples, as well as facilitating in-depth studies of its biological functions.

Correlation between viscoelastic response and frictional properties of hydrated zwitterionic polymer brush film in narrowing shear gap

HypothesisA hydrated 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer brush exhibits exceptional lubricity. This lubrication mechanism has traditionally been attributed to either the inherent fluidity of the brush or the water film that forms owing to its hydrophilic nature. Given previous findings that the frictional properties of the MPC polymer brush film show load dependence, we hypothesize that the lubrication mechanism can be elucidated by examining the shear gap (varies owing to the load) dependence of the brush’s viscoelastic response. ExperimentsMPC polymer brush films with different thicknesses were prepared. Their viscoelastic responses were evaluated across different shear gap widths, and the frictional properties were subsequently compared across states with distinct viscoelastic behaviors. FindingsThe observed shear viscoelasticity demonstrated a clear gap dependence that correlated with frictional attributes. Our data suggests that the lubrication mechanism shifts based on the shear gap. Specifically, two states exhibited low coefficients of friction: one where the osmotic pressure supports the load while allowing flexible deformation of the brush film, and the other where the brush film undergoes compression and transitions to a fully elastic state.

A-364 The Utility of the Highly Sensitive Detection System for Immunochromatographic Assay by Addition of MPC polymer

Abstract Background Immunochromatographic assay (ICA) is frequently used as a point-of-care testing (POCT) in the field of infectious diseases, but it has a problem of low detection sensitivity. Many interfering substances in ICA test materials have been reported to case a decrease in detection sensitivity. For the purpose of increasing the sensitivity of ICA, bovine serum albumin or a polymer with phosphorylcholine groups (MPC polymer) has been used as an additive to a sample diluent. In this study, we evaluated the usability of the sensitizing effect for the addition of MPC polymer with a serum-based HBs antigen test kit. Methods A 2-fold dilution series of a commercially available control serum (Infectrol D, SeraCare Life Sciences, Inc. manufacturer's reference value 108.674 IU/mL) containing 0.05%, 0.10%, 0.5% of several MPC polymers (Biolipidure® from NOF Corporation) as final concentration were prepared with HBs antigen negative serum. The optimal type of MPC polymer and the concentrations added to the sera were determined by comparing the color intensity of their test lines in the evaluation of each test sample with a commercially available test kit (Quick Chaser® from MIZUHO MEDY Co., Ltd.). The color intensities of the test lines were quantified with an immunochromatographic reader. In addition, the correlation of two different test kits (ESPLINE® from FUJIREBIO and Quick Chaser® from MIZUHO MEDY Co., Ltd.) was evaluated with sera obtained from HBs antigen-positive patients regarding the three types of MPC polymer which were improved the detection sensitivity in the evaluation with the control serum. The measurements were performed in triplicate after 0.5% of MPC polymer as final concentration was added to each diluted serum. Results Antigen amount for diluted sera with MPC polymer were determined by CLEIA method, and no difference in the antigen amount was observed regardless of the addition or the types of MPC polymer. In addition, the color intensity in each dilution series was compared to the cutoff value, which is average value of the color intensity of negative control serum without MPC polymer. In the evaluation with control serum, the test line in the case without MPC polymer enabled to detect up to 2-fold diluted control serum while the test line in the case with MPC polymer enabled to detect up to 32-fold diluted control serum. The addition of MPC polymer in the evaluation with sera obtained from HBs antigen-positive patients was also confirmed that the detection sensitivity enhanced up to 8-fold higher in ESPLINE® and up to 4-fold higher in Quick Chaser®. Conclusion The color intensity of the test line enhanced by the addition of MPC polymer. In particular, when the highly hydrophilic and anionic MPC polymer was added, the test line was detected narrower and darker, and we believe that the increased color intensity resulted in improved sensitivity. By considering the influence of interfering substances in clinical materials and the physical properties of the MPC polymer (hydrophobicity, molecular size, etc.), it is expected that the sensitivity of the ICA will be increased to be more suitable for clinical materials.

Solubilization of Poorly Water-soluble Drugs with Amphiphilic Phospholipid Polymers

Most drug candidates developed in recent years are poorly water-soluble, which is a key challenge in pharmaceutical science. Various solubilization methods have been investigated thus far, most of which require solubilizers that provide a local hydrophobic environment wherein a drug can dissolve or induce interactions with drug molecules. We have focused on amphiphilic 2-methacryloyloxyethyl phosphoryl choline (MPC) polymers. In addition to the ease of molecular design of amphiphilic MPC polymers owing to their chemical structures, they have been reported to possess high biocompatibility in various biomaterial applications. Additionally, amphiphilic MPC polymers have been applied in the pharmaceutical field, especially in solubilization. We have qualitatively and quantitatively evaluated the effects of the chemical structure and physical properties of the solubilizer on the MPC polymers. In particular, MPC polymers with different chemical structures were designed and synthesized. The inner polarity and molecular mobility in the polymer aggregates were evaluated, indicating that the intrinsic properties reflect the chemical structure of the polymer. Additionally, amphiphilic MPC polymers were used to improve the solubility of poorly water-soluble drugs and as solid dispersion carriers, and they exhibited superior solubilizing abilities compared to a commonly used polymer. Furthermore, the solubility of biopharmaceuticals, such as peptides, was improved. It is possible to design and synthesize optimal structures based on the polarity of the hydrophobic environment and the intermolecular interaction with a drug. This research provides a unified interpretation of drugs and efficiently summarizes knowledge about drug development, which will facilitate the efficient and rapid development of drug formulations.

Surface Functionalization of Diamond-like Carbon Film with Biocompatible Polymer Brushes

Biocompatible polymer brushes were successfully synthesized on diamond-like carbon (DLC) films via surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-mtharyloyloxyethyl phosphorylcholine (MPC). The DLC film with a water contact angle (WCA) of approximately 71.9° was modified into a highly hydrophilic surface with a WCA of approximately 15.0° after MPC polymer brush modification. Protein adsorption tests using a quartz crystal microbalance showed that the MPC polymer brush modification dramatically decreased the physical adsorption of bovine albumin and fibrinogen when compared with the DLC film. This indicated an improvement in the surface biocompatibility. Considering that DLC coatings can be applied to various materials such as metals, polymers, and ceramics, MPC polymer brush modification of DLC films would be a versatile technology for improving the surface biocompatibility of a variety of biomedical devices.

Combination of MPC Polymer Enhances the Dry Eye Therapy in Commercially Available Diquafosol Sodium and Sodium Hyaluronate Eye Drops

Combination of MPC Polymer Enhances the Dry Eye Therapy in Commercially Available Diquafosol Sodium and Sodium Hyaluronate Eye Drops

The Influence of 2-Methacryloyloxyethyl Phosphorylcholine Polymer Materials on Orthodontic Friction and Attachment of Oral Bacteria.

There is no clinical evidence of the usage of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers in dental practice. We performed in vitro studies to determine whether the application of an MPC coating to stainless steel orthodontic wires confers low-friction and antimicrobial properties to these wires. The friction test on MPC-coated wires was performed using a precision universal/tensile tester. MPC polymer was coated on a 50 × 50 mm stainless steel plate, and samples were assessed using an antimicrobial activity test. To verify the effect of MPC polymer-treated wires on experimental tooth movement models in vitro, examinations were performed on typodonts to determine the improvement in tooth movement efficiency. The polymer treatment wire groups demonstrated significantly enhanced tooth movement compared with the untreated wire groups, at both 50 g and 100 g traction forces. The results indicated that MPC coating inhibited the attachment of oral bacteria, such as Streptococcus mutans, on a stainless steel plate. Additionally, the coating seemed to improve the efficiency of tooth movement by reducing the occurrence of friction. The application of an MPC coating onto stainless steel wires, which are used as orthodontic materials, may reduce static friction and bacterial adherence to the oral cavity and improve tooth movement.

Dissolvable conducting polymer supercapacitor for transient electronics

This work explores the use of a conducting polymer that can dissolve in mild aqueous conditions as a supercapacitor material for applications in transient electronics, biomedical devices, and biodegradable energy storage. A repeating polymer of methyl 1H-pyrrole-3-carboxylate monomer (“MPC polymer”) is prepared via electrochemical and chemical polymerization methods, and tested for the first time as a supercapacitor energy storage material. The MPC polymer exhibits charge storage performance comparable to pseudocapacitive conducting polymer polypyrrole (PPY), both as a planar electrode and as a composite porous electrode with poly (l-lactic acid) (PLLA). Chronoamperometry charge-discharge results indicate that the MPC polymer stores energy as a pseudocapacitive material following a faradaic current model. Electrochemical impedance spectroscopy (EIS) measurements demonstrate that MPC polymer electrodes have lower equivalent series and charge transfer resistance compared to PPY electrodes. Cycle life testing of MPC polymer and PPY electrodes shows equal capacitance loss for both electrodes over 1100 cycles. After use as a supercapacitor electrode with an organic electrolyte, MPC polymer-based electrodes showed visible signs of degradation in a mild aqueous environment (37 °C, pH 8.2) in 8 h.

Improved biotribological performance of Ti6Al4V alloy through the synergetic effects of porous TiO2 layer and zwitterionic hydrogel coating

To improve the biotribological properties of Ti6Al4V alloy for artificial joints, motivated by the composite structure of ‘natural articular cartilage - subchondral bone’ and the hydration lubrication mechanism of articular cartilage, a soft/hard bilayer coating composed of a porous TiO 2 layer and a zwitterionic hydrogel coating was designed and fabricated on Ti6Al4V alloy through micro-arc oxidation (MAO) combined with ultraviolet (UV) radiation technology. Characterization results revealed that the bio-inspired bilayer coating could be successfully constructed on Ti6Al4V alloy, and such a coating displayed good hydrophilicity (WCA: 32°). Notably, by ball - on - disk friction test, this biomimetic bilayer coating exhibited an ultra-low friction coefficient (∼0.038) in PBS solution, which was reduced by an order of magnitude compared with that of the Ti6Al4V alloy substrate. This was due to the synergistic effects of soft/hard composite structure and the hydration lubrication of zwitterionic MPC polymer. This work provides a novel and effective strategy for surface modification of Ti6Al4V alloy for artificial joints.

Emerging Phospholipid Nanobiomaterials for Biomedical Applications to Lab-on-a-Chip, Drug Delivery, and Cellular Engineering.

The design of advanced nanobiomaterials to improve analytical accuracy and therapeutic efficacy has become an important prerequisite for the development of innovative nanomedicines. Recently, phospholipid nanobiomaterials including 2-methacryloyloxyethyl phosphorylcholine (MPC) have attracted great attention with remarkable characteristics such as resistance to nonspecific protein adsorption and cell adhesion for various biomedical applications. Despite many recent reports, there is a lack of comprehensive review on the phospholipid nanobiomaterials from synthesis to diagnostic and therapeutic applications. Here, we review the synthesis and characterization of phospholipid nanobiomaterials focusing on MPC polymers and highlight their attractive potentials for applications in micro/nanofabricated fluidic devices, biosensors, lab-on-a-chip, drug delivery systems (DDSs), COVID-19 potential usages for early diagnosis and even treatment, and artificial extracellular matrix scaffolds for cellular engineering.

Solubilization of Paclitaxel by Self-Assembled Amphiphilic Phospholipid-Mimetic Polymers with Varied Hydrophobicity.

2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers have been used as a coating agent on medical devices and as a carrier in drug delivery systems (DDSs). Paclitaxel (PTX) is a water-insoluble anticancer drug whose solubilizer is necessary for administration. Block and random copolymers composed of hydrophilic MPC and butyl methacrylate, named PMB, show different properties, depending on the polymer sequence and MPC content. In the present study, we used amphiphilic MPC polymers comprising hydrophobic dodecyl methacrylate (DMA). The self-assembling properties and PTX solubilization of random and block poly(MPC-co-DMA)s (rPMDs and bPMDs) with different compositions were examined and compared. rPMDs with high DMA content formed large and relatively loose self-assembled structures, which solubilized PTX. However, bPMDs formed small and compact self-assembled structures with poor PTX solubilization. PTX solubilized by PMB with small and loose self-assembled structures showed efficient drug action, similar to free PTX; however, rPMDs fell short of demonstrating PTX efficiency. Our results suggest that the self-assembling properties and the hydrophobicity of amphiphilic MPC polymers largely affect PTX solubilization as well as drug action, which is required to be controlled by the polymer sequence, as well as the structure and composition of the hydrophobic monomer for efficient DDS.

Application of Zwitterionic Polymer Hydrogels to Optical Tissue Clearing for 3D Fluorescence Imaging.

Zwitterionic polymers have both anion and cation groups in the side chain and have been used in various biomedical applications because of the unique properties. In this study, zwitterionic polymer hydrogels are applied to optical tissue clearing for 3D fluorescence imaging. Polyacrylamide hydrogels have been employed in Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/Immunostaining/In situ-hybridization-compatible Tissue-hYdrogel method. Zwitterionic polymer hydrogels are produced using zwitterionic monomers, such as 3-[(3-acrylamidopropyl)dimethylammonio]propane-1-sulfonate (DAPS) and 2-methacryloyloxyethyl phosphorylcholine (MPC), and crosslinkers. The hydrogels made from poly(DAPS-co-acrylamide) and MPC homopolymers afford the most transparent tumor tissues. However, the tissues cleared using DAPS copolymers-containing hydrogels became turbid in a refractive index-matching solution, which are unable to obtain clear 3D fluorescence images. In contrast, the 3D fluorescence imaging is achieved in the MPC polymer-treated 2-mm-thick brain slices after immunostaining. The 3D fluorescence imaging of lung metastasis that is cleared by the MPC hydrogel to demonstrate the possible application to cancer diagnosis is performed. The results indicate the increased potentials of zwitterionic polymer hydrogels, especially MPC polymer hydrogels, in biomedical applications.

Design of Intelligent Interface Based on Cytocompatible Polymers for Control on Cell Function

Bioinspired polymeric biomaterials with excellent cytocompatibility have been designed in this study. 2-Methacryloyloxyehtyl phosphorylcholine (MPC) is a phospholipid polymer and an essential polymeric biomaterial, which has been used in various biomedical and pharmaceutical applications including implantable medical devices. Furthermore, it is a methacrylate monomer unit and can be copolymerized with other vinyl monomers via conventional radical polymerization. The water-solubility of MPC polymers depends on the molecular composition and molecular weight of the polymers. PMB is a water-soluble polymer copolymerized with hydrophobic n-butyl methacrylate, and can be used as a solubilizing agent for poorly soluble drugs. The phospholipid polymers showed low cytotoxicity, and the solubilized drugs effectively not only penetrated into the cells but also into the surrounding tissues. In addition, the water-soluble MPC polymer containing a phenylboronic acid moiety was observed to spontaneously form polymeric hydrogels with polyol compounds. The reversible polymer hydrogels were used as artificial extracellular matrices for cell immobilization and cell engineering. Polymeric biomaterials with intelligent interfaces might be explored as innovative techniques for application in pharmaceutical and life sciences.

Evaluation of 2-methacryloyloxyethyl phosphorylcholine polymer coated polyamide denture base material: Surface Roughness and Candida Albicans adhesion.

Purpose: To evaluate Candida albicans adhesion and the surface roughness of polyamide denture base material coated with various concentrations of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer. Materials and Methods: A total of 80 disks polyamide resin specimens were fabricated and divided into 4 groups (n = 20/group). Surfaces of the specimens in three groups were coated with MPC in different concentrations (0.25 mol/L; 0.50 mol/L and 0.75 mol/L), while uncoated specimens were used as control. Surface roughness (SR) was evaluated using a profilometer. Specimens were incubated with C. albicans for 18 h and the number of adhered cells was determined. Statistically, the following tests were done: analysis of variance, Pearson correlation coefficient test, post hoc Tukey test. Results: Upon PMPC coating, surface roughness values were decreased, with a significant difference between different groups. A statistically significant decrease was observed in C. albicans adhesion in parallel with the increase in the MPC polymer concentration. There was no significant difference between 0.50 mol/L and 0.75 mol/L groups in terms of adhesion. These findings indicated that graft polymerization of MPC on polyamide denture base material reduces the adhesion of C. albicans, and may be evaluated as a coating for prevention of denture stomatitis. Conclusion: Coating of removable prosthesis with 0.75 mol/L MPC is suitable to reduce C. albicans adhesion on polyamide denture base.

Antifouling Silicone Hydrogel Contact Lenses with a Bioinspired 2-Methacryloyloxyethyl Phosphorylcholine Polymer Surface.

Inspired by the cell membrane surface as well as the ocular tissue, a novel and clinically applicable antifouling silicone hydrogel contact lens material was developed. The unique chemical and biological features on the surface on a silicone hydrogel base substrate were achieved by a cross-linked polymer layer composed of 2-methacryloyloxyethyl phosphorylcholine (MPC), which was considered important for optimal on-eye performance. The effects of the polymer layer on adsorption of biomolecules, such as lipid and proteins, and adhesion of cells and bacteria were evaluated and compared with several conventional silicone hydrogel contact lens materials. The MPC polymer layer provided significant resistance to lipid deposition as visually demonstrated by the three-dimensional confocal images of whole contact lenses. Also, fibroblast cell adhesion was decreased to a 1% level compared with that on the conventional silicone hydrogel contact lenses. The movement of the cells on the surface of the MPC polymer-modified lens material was greater compared with other silicone hydrogel contact lenses indicating that lubrication of the contact lenses on ocular tissue might be improved. The superior hydrophilic nature of the MPC polymer layer provides improved surface properties compared to the underlying silicone hydrogel base substrate.

MPC Polymer Promotes Recovery from Dry Eye via Stabilization of the Ocular Surface.

The polymer that includes 2-methacryloyloxy ethyl phosphorylcholine (MPC) is well-known as an effectively hydrating multifunction agent. In this study, we prepared an MPC polymer (MPCP) using radical polymerization with co-monomers—MPC/Stearyl Methacrylate/N,N-dimethylacrylamide—and evaluated the MPCP’s usefulness for dry eye treatment using a rabbit model treated with N-acetylcysteine. The MPCP particle size was 50–250 nm, and the form was similar to that of micelles. The MPCP viscosity (approximately 0.95 mPa·s) was 1.17-fold that of purified water, and a decrease in the transepithelial electrical resistance value (corneal damage) was not observed in the immortalized human corneal epithelial cell line HCE-T cell (HCE-T cell layer). The MPCP enhanced the water maintenance on the cornea, and the instillation of MPCP increased the lacrimal fluid volume and prolonged the tear film breakup time without an increase in total mucin contents in the lacrimal fluid of the normal rabbits. The therapeutic potential of the MPCP for dry eye was evaluated using an N-acetylcysteine-treated rabbit model, and, in our investigation, we found that MPCP enhanced the volume of lacrimal fluid and promoted an improvement in the tear film breakup levels. These findings regarding the creation and characteristics of a novel MPCP will provide relevant information for designing further studies to develop a treatment for dry eyes.