2-methacryloyloxyethyl Phosphorylcholine Research Articles

Use of catheter with 2-methacryloyloxyethyl phosphorylcholine polymer coating is associated with long-term availability of central venous port

Central venous port (CVP) is a widely used totally implantable venous access device. Recognition of risks associated with CVP-related complications is clinically important for safe, reliable, and long-term intravenous access. We therefore investigated factors associated with CVP infection and evulsion, including the device type. A total of 308 consecutive patients with initial CVP implantation between January 2011 and December 2017 were retrospectively reviewed, and the association of clinical features with CVP-related complications were analyzed. Intraoperative and postoperative complications occurred in 11 (3.6%) and 39 (12.7%) patients, respectively. The overall rate of CVP availability at six months was 91.4%. Malignancy and 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated catheter use were negatively associated with the incidence of CVP infections. Accordingly, malignancy and MPC polymer-coated catheter use were independent predictors for lower CVP evulsion rate (odds ratio, 0.23 and 0.18, respectively). Furthermore, both factors were significantly associated with longer CVP availability (hazard ratio, 0.24 and 0.27, respectively). This retrospective study identified factors associated with CVP-related complications and long-term CVP availability. Notably, MPC polymer-coated catheter use was significantly associated with a lower rate of CVP infection and longer CVP availability, suggesting the preventive effect of MPC coating on CVP infection.

Formulation and Biocompatibility of Microemulsion-Based PMBN as an Efficient System for Paclitaxel Delivery

Introduction: Paclitaxel (PTX), an effective chemotherapeutic drug, is widely used to treat several types of cancers. However, its use is limited due to poor water solubility resulted in poor bioavailability. One of the main ways to increase the efficacy and endurance of medications depends on the carrier that used for it. In the current study, the microemulsions (ME) were investigated based on Poly [2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-p-nitrophenyl-oxycrabonyl poly ethylene glycol-methacrylate (ME-ONP)] (PMBN) ability as a carrier for PTX to increase the half-life and its bioavailability. Also, the physicochemical properties of the ME system were evaluated. Materials and Methods: PMBN, tween 80, triacetin, and glycerol were used as the drug carrier, surfactant, oil phase, and co-surfactant, respectively. The hemolytic activity was characterized using the RBC hemolysis assay to evaluate the blood compatibility of the MEs. In addition, the in vitro cytotoxic effect of PMBN-PTX-ME and PTX on MCF-7, 4T1, and HFF-2 cell lines was performed. PI and Annexin-V dyes were used for cell apoptosis. Results: The conductivity of ME evaluated and the results showed 432 to 589 µS/cm. In vitro, the drug release study revealed that PTX has controlled release at different pH levels. Refractive Index (RI) and % transmittance of the MEs remained ranging from 1.43 to 1.53, and 89% to 98%, respectively. The MTT assay determined that PMBN-ME without PTX had no significant toxicity on HFF-2, MCF-7, and 4T-1 cell lines. Based on the apoptosis assay, treated cell lines with PMBN approximately remained alive. Conclusions: The results revealed that ME-based on PMBN would be a promising drug delivery system for PTX drug delivery.

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.

Antibiofilm and Protein-Repellent Polymethylmethacrylate Denture Base Acrylic Resin for Treatment of Denture Stomatitis.

Candida albicans (C. albicans) biofilm is a common etiological factor in denture stomatitis. The purpose of this study was to investigate the effects of incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC) as a protein repellent into a new high-impact denture acrylic (HIPA) resin on the surface roughness, solution pH, and C. albicans biofilm adhesion to the denture base. The new acrylic denture resin base was formulated by mixing MPC into HIPA resin at mass fractions of 1.5%, 3%, and 4.5%. Surface roughness was measured using a Mitutoyo surface roughness tester. C. albicans biofilm growth and viability were assessed via colony forming unit counts. The pH of the biofilm growth medium was measured using a digital pH meter. Adding MPC to the HIPA resin at percentages of 1.5% and 3% increased the roughness values significantly (p < 0.05), while adding 4.5% MPC resulted in no difference in roughness values to that of the control group (p > 0.05). All experimental groups demonstrated neutral pH values (pH ≅ 7) and were not significantly different from each other (p > 0.05). Incorporating 2-methacryloyloxyethyl phosphorylcholine at 4.5% resulted in a significant (≅1 log) colony-forming unit reduction compared with the control group with 0% MPC (p < 0.05). A fungal-retarding denture acrylic resin was developed through the incorporation of MPC for its protein-repelling properties. This newly developed denture acrylic material has the potential to prevent oral microbial infections, such as denture stomatitis.

Antifouling and Antibacterial Polymer-Coated Surfaces Based on the Combined Effect of Zwitterions and the Natural Borneol.

The development and application of natural antibacterial materials have always been the focus of biomedical research. Borneol as a natural antibacterial compound has received extensive attention. However, the hydrophobicity caused by its unique structure limits its application range to a certain extent. In this study, we combine zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) with a complex bicyclic monoterpene structure borneol compound and prepare an excellent antifouling and antibacterial surface via the Schiff-base bond. The prepared coating has excellent hydrophilicity verified by the contact angle (CA), and its polymer layer is confirmed by X-ray photoelectron spectroscopy (XPS). The zwitterion MPC and borneol moieties in the copolymer play a coordinating role, relying on super hydration and the special stereochemical structure to prevent protein adsorption and inhibit bacterial adhesion, respectively, which are demonstrated by bovine serum albumin (BSA) adsorption and antibacterial activity test. Moreover, the water-soluble borneol derivative as the antibacterial surfaces we designed here was biocompatible toward MRC-5 (lung fibroblasts), as showed by in vitro cytotoxicity assays. Such results indicate the potential application of the as-prepared hydrophilic surfaces in the biomedical materials.

The long observation in vitro of prevention effect of novel self-etching orthodontic adhesive modified with 2-methacryloxyethyl phosphorylcholine in enamel demineralization.

The enamel demineralization is common in fixed orthodontics. Plaque accumulation around the bracket plays a critical role and could cause various degrees of white spot lesions (WSLs) on the surface of teeth. The 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer is a biological polymer with protein repellent and an anti-bacterial adhesion effects. In this study, the enamel shear bond strength (SBS) and protein repellent property in vitro of self-etching orthodontic adhesive with MPC were evaluated. It was found that the self-etching adhesive with 0-7.5%MPC met the orthodontic clinical requirement on the SBS values at three different points of time. The incorporation of 7.5%MPC significantly reduced the bacterial adhesion and total microorganism of the yield biofilm. Moreover, the MTT assay showed that the amount of plaque metabolism in 7.5%MPC was the lowest among the groups. To conclude, the novel protein repellent self-etching adhesive was able to inhibit biofilm formation efficiently and minimize enamel demineralization.

PMPC Modified PAMAM Dendrimer Enhances Brain Tumor-Targeted Drug Delivery.

The excellent biocompatibility drug delivery system for effective treatment of glioma is still greatly challenged by the existence of blood-brain barrier, blood-brain tumor barrier, and the tissue toxicity caused by chemotherapy drugs. In this study, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) is used for the first time for modifying third-generation poly(amidoamine) (PAMAM) to enhance their brain tumor-targeted drug delivery ability as well as simultaneously reducing the toxicity of PAMAM dendrimers and the tissue toxicity of the loaded doxorubicin (DOX). The cytotoxicity, the therapeutic ability in vitro, and the brain tumor-targeted ability of the PMPC modified PAMAM nanoparticles are further studied. Results indicate that PMPC, as a dual-functional modifier, can significantly reduce the cytotoxicity of PAMAM dendrimers, while efficiently target the brain tumor. In addition, the therapeutic effect of DOX-loaded PAMAM-PMPC in mice inoculated with U-87 is also studied in vivo. In comparison with DOX solution, DOX-loaded PAMAM-PMPC alleviates weight loss of tumor-inoculated mice and reduces the cardiotoxicity of DOX. The tumor growth inhibition, in vivo, is significantly increased up to (80.76±1.66)%. In conclusion, this strategy of PMPC dual-functional targeted nanocarrier provides a new method for the delivery of chemotherapeutic drugs to treat glioma.

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.

Drug-Eluting Hydrophilic Coating Modification of Intraocular Lens via Facile Dopamine Self-Polymerization for Posterior Capsular Opacification Prevention.

Posterior capsular opacification (PCO) is the most important complication in cataract phacoemulsification and intraocular lens (IOL) implantation surgery, mainly stemming from the adhesion, proliferation, and transdifferentiation of the postsurgically residual lens epithelial cells (LECs). Previous investigations mainly focused on the hydrophilic surface modification of the IOLs for PCO prevention, such as heparinization. However, the long-term clinical investigations show that there is no significant difference between pristine and heparinized IOLs. In the present study, a synergetic coating with properties of drug-eluting and hydrophilicity was designed and modified onto the IOL surface via facile dopamine self-polymerization. The antiproliferative drug doxorubicin (DOX) was loaded when a polydopamine (PDA) coating was formed on the IOL surface. The hydrophilic 2-methacryloyloxyethyl phosphorylcholine (MPC) could be subsequently grafted onto the drug-loaded PDA coating surface easily. The hydrophilic outer layer could slow down drug-eluting from underneath the drug-incorporated coating. In vitro and in vivo investigations demonstrated that such multifunctionalized coating-modified IOLs could not only thoroughly and effectively prevent PCO development by induced cell apoptosis but also render safety and biocompatibility to the surrounding tissues.

Poly[2-(methacryloyloxy)ethyl phosphorylcholine]-Stabilized graphene-iron oxide composites for water splitting

The electrolysis of water is considered as a potentially realistic technology for the massive production of hydrogen. The use of graphene composites in electrocatalytic water splitting has been extensively investigated. Graphene-iron oxide composites were prepared via in situ polymerization of 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) and poly (ethylene glycol) monomethacrylate (PEG) on graphene surface (non-oxidative graphite-HOPG/G) in presence of iron oxide nanoparticles (IONPs) and denoted as G-INSCP. Copolymers PMPC-co-PEG (CP) and block copolymer PMPC-b-PEG (BCP) were prepared and their structures were thoroughly characterized. These polymers were used to prepare G-INSCP, G-CP, and G-BCP, their stabilities were compared and their morphologies were studied. HOPG, G-CP, and G-INSCP were used in the hydrogen evolution reaction (HER) as effective platinum catalyst alternatives. G-BCP composite was excluded owing to its very low stability. To evaluate the performance of these electrocatalysts in acidic media, linear sweep voltammetry and electrochemical impedance spectroscopy were employed. Results revealed that, compared with HOPG and G-CP, G-INSCP exhibited a significantly improved catalytic activity with respect to HER in an acidic electrolyte. Additionally, at a current density of 10 mA cm−2, G-INSCP demonstrated a lower overpotential and Tafel slope of 95 mVRHE and 67 mV dec−1, respectively. These observations were attributed to the synergistic effect between the magnetic IONPs and PMPC polymer along with the increase in the electron transfer rate owing to the conductive graphene in the catalyst. Thus G-INSCP catalyst can be a potential candidate for HER and paving the way for the advancement of new and similar catalysts for other applications.

Short-term clinical and radiographic outcomes of total hip arthroplasty with PMPC-grafted highly cross-linked polyethylene liners against 32-mm femoral heads

We evaluated the clinical and radiographic outcomes of femoral head penetration and total hip arthroplasties with untreated and poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted highly cross-linked polyethylene (HXLPE) acetabular liners against 26-, 28-, and 32-mm cobalt–chromium alloy femoral heads 3 years after the index surgery. Three combinations of the articulating surfaces were evaluated in the present study: untreated or PMPC-grafted HXLPE liner against 26- or 28-mm femoral heads (n = 16, 24) [control (26 or 28 mm) and PMPC (26 or 28 mm)] and PMPC-grafted HXLPE liner against 32-mm femoral heads (n = 64) [PMPC (32 mm)]. The clinical outcomes improved at 3 years postoperatively for the groups. No periprosthetic osteolysis or acetabular component migration was detected, and no revision surgery was performed among the groups. The steady-state wear rate of the PMPC (26 or 28 mm) group (0.021 mm/year) was lower than that of the control (26 or 28 mm) group (− 0.015 mm/year); the steady-state wear was under the clinical threshold. In contrast, the steady-state wear rate of the PMPC (32 mm) group (-0.006 mm/year) showed no significant difference when compared to that of the PMPC (26 or 28 mm) group (p < 0.01). The results obtained in the present study clearly demonstrate that PMPC-grafting onto an HXLPE surface improved the wear resistance of acetabular liners, even when coupled with larger femoral heads. Although further follow-up evaluations are required, PMPC-grafted HXLPE acetabular liners may be a promising approach to extend the longevity of artificial joints.

Gelatin-based composite hydrogels with biomimetic lubrication and sustained drug release

The occurrence of osteoarthritis is closely related to progressive and irreversible destruction of the articular cartilage, which increases the friction significantly and causes further inflammation of the joint. Thus, a scaffold for articular cartilage defects should be developed via lubrication restoration and drug intervention. In this study, we successfully synthesized gelatin-based composite hydrogels, namely GelMA-PAM-PMPC, with the properties of biomimetic lubrication and sustained drug release by photopolymerization of methacrylic anhydride modified gelatin (GelMA), acrylamide (AM), and 2-methacryloyloxyethyl phosphorylcholine (MPC). Tribological test showed that the composite hydrogels remarkably enhanced lubrication due to the hydration lubrication mechanism, where a tenacious hydration shell was formed around the zwitterionic phosphocholine headgroups. In addition, drug release test indicated that the composite hydrogels efficiently encapsulated an anti-inflammatory drug (diclofenac sodium) and achieved sustained release. Furthermore, the in vitro test revealed that the composite hydrogels were biocompatible, and the mRNA expression of both anabolic and catabolic genes of the articular cartilage was suitably regulated. This indicated that the composite hydrogels could effectively protect chondrocytes from inflammatory cytokine-induced degeneration. In summary, the composite hydrogels that provide biomimetic hydration lubrication and sustained local drug release represent a promising scaffold for cartilage defects in the treatment of osteoarthritis.

Durable Oral Biofilm Resistance of 3D-Printed Dental Base Polymers Containing Zwitterionic Materials.

Poly(methyl methacralyate) (PMMA) has long been used in dentistry as a base polymer for dentures, and it is recently being used for the 3D printing of dental materials. Despite its many advantages, its susceptibility to microbial colonization remains to be overcome. In this study, the interface between 3D-printed PMMA specimens and oral salivary biofilm was studied following the addition of zwitterionic materials, 2-methacryloyloxyethyl phosphorylcholine (MPC) or sulfobetaine methacrylate (SB). A significant reduction in bacterial and biofilm adhesions was observed following the addition of MPC or SB, owing to their protein-repellent properties, and there were no significant differences between the two test materials. Although the mechanical properties of the tested materials were degraded, the statistical value of the reduction was minimal and all the properties fulfilled the requirements set by the International Standard, ISO 20795-2. Additionally, both the test materials maintained their resistance to biofilm when subjected to hydrothermal fatigue, with no further deterioration of the mechanical properties. Thus, novel 3D-printable PMMA incorporated with MPC or SB shows durable oral salivary biofilm resistance with maintenance of the physical and mechanical properties.

Injectable hydrogels self-assembled from oligopeptide-poly(2-methacryloyloxyethyl phosphorylcholine) hybrid graft copolymers for cell scaffolds and controlled release applications

An injectable hydrogel composed of biocompatible PMPC with PEG-attached self-assembling peptide grafts was newly prepared, and it could be used as 3D cell scaffolds and controlled-release applications.

Light-responsive dual-functional biodegradable mesoporous silica nanoparticles with drug delivery and lubrication enhancement for the treatment of osteoarthritis.

Visible light-responsive dual-functional biodegradable mesoporous silica nanoparticles with drug delivery and lubrication enhancement were constructed by supramolecular interaction between azobenzene-modified mesoporous silica nanoparticles (bMSNs-AZO) and β-cyclodextrin-modified poly(2-methacryloyloxyethyl phosphorylcholine) (CD-PMPC). Visible light could effectively trigger azobenzene isomerization and thus induce drug release after passing through the dermal tissue. Additionally, the hydration layer formed by CD-PMPC on the surface of the nanoparticles played an important role in lubrication enhancement, which was beneficial for the treatment of osteoarthritis.

Early administration of MPC-n(IVIg) selectively accumulates in ischemic areas to protect inflammation-induced brain damage from ischemic stroke.

Ischemic stroke is an acute and severe neurological disease, which leads to disability and death. Immunomodulatory therapies exert multiple remarkable protective effects during ischemic stroke. However, patients suffering from ischemic stroke do not benefit from immunomodulatory therapies due to the presence of the blood-brain barrier (BBB) and their off-target effects.Methods: We presented a delivery strategy to optimize immunomodulatory therapies by facilitating BBB penetration and selectively delivering intravenous immunoglobulin (IVIg) to ischemic regions using 2-methacryloyloxyethyl phosphorylcholine (MPC)-nanocapsules, MPC-n(IVIg), synthesized using MPC monomers and ethylene glycol dimethyl acrylate (EGDMA) crosslinker via in situ polymerization. In vitro and in vivo experiments verify the effect and safety of MPC-n(IVIg).Results: MPC-n(IVIg) efficiently crosses the BBB and IVIg selectively accumulates in ischemic areas in a high-affinity choline transporter 1 (ChT1)-overexpression dependent manner via endothelial cells in ischemic areas. Moreover, earlier administration of MPC-n(IVIg) more efficiently deliver IVIg to ischemic areas. Furthermore, the early administration of low-dosage MPC-n(IVIg) decreases neurological deficits and mortality by suppressing stroke-induced inflammation in the middle cerebral artery occlusion model.Conclusion: Our findings indicate a promising strategy to efficiently deliver the therapeutics to the ischemic target brain tissue and lower the effective dose of therapeutic drugs for treating ischemic strokes.

Thermo-Responsive Behavior of Mixed Aqueous Solution of Hydrophilic Polymer with Pendant Phosphorylcholine Group and Poly(Acrylic Acid).

A mixed aqueous solution of hydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(acrylic acid) (PAAc) becomes cloudy under acidic conditions at room temperature. The pendant carboxylic acid groups in PAAc form hydrogen bonds with the ester and phosphate groups in PMPC. While the polymers aggregate under acidic conditions, neither one associate under basic conditions because of the deprotonation of the pendant carboxy groups in PAAc. We observed that the interpolymer complex formed from PMPC, and PAAc was dissociated in aqueous solutions with increasing temperature, which is an upper critical solution temperature behavior. With increasing temperature, the molecular motion increased to dissociate the interpolymer complex. The phase transition temperature increased with increasing polymer and salt concentrations, and with decreasing pH.

Synthesis of poly(2-methacryloyloxyethyl phosphorylcholine)-conjugated lipids and their characterization and surface properties of modified liposomes for protein interactions.

Poly(ethylene glycol) (PEG) is frequently used for liposomal surface modification. However, as PEGylated liposomes are cleared rapidly from circulation upon repeated injections, substitutes of PEG are being sought. We focused on a water-soluble polymer composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) units, and synthesized poly(MPC) (PMPC)-conjugated lipid (PMPC-lipid) with degrees of MPC polymerization ranging from 10 to 100 (calculated molecular weight: 3 to 30 kDa). In addition, lipids with three different alkyl chains, myristoyl, palmitoyl, and stearoyl, were applied for liposomal surface coating. We studied the interactions of PMPC-lipids with plasma albumin, human complement protein C3 and fibrinogen using a quartz crystal microbalance with energy dissipation, and found that adsorption of albumin, C3 and fibrinogen could be suppressed by coating with PMPC-lipids. In particular, the effect was more pronounced for PMPC chains with higher molecular weight. We evaluated the size, polydispersity index, surface charge, and membrane fluidity of the PMPC-lipid-modified liposomes. We found that the effect of the coating on the dispersion stability was maintained over a long period (98 days). Furthermore, we also demonstrated that the anti-PEG antibody did not interact with PMPC-lipids. Thus, our findings suggest that PMPC-lipids can be used for liposomal coating.

Phosphorylcholine-Grafted Molecular Bottlebrush-Doxorubicin Conjugates: High Structural Stability, Long Circulation in Blood, and Efficient Anticancer Activity.

Controlling the particle structure of tumor-targeting nanomedicines in vivo remains challenging but must be achieved to control their in vivo fate and functions. Molecular bottlebrushes (MBs), where brush side chains are densely grafted from a main chain, have recently received attention as building blocks of polymer-based prodrugs because their rigid structure would be expected to demonstrate high structural stability in vivo. Here, we synthesized a poly(methacryloyloxyethyl phosphorylcholine) (pMPC)-grafted molecular bottlebrush (PCMB) conjugated with a cancer drug, doxorubicin (DOX), via an acid-cleavable hydrazone bond. A pMPC-based linear polymer (LP) conjugated with DOX was also prepared for comparison. We confirmed the lack of structural transition in the PCMB between before and after conjugation with DOX using small-angle light and X-ray scattering techniques, whereas the structure of LP was significantly influenced by DOX conjugation and transformed from a random-coil structure to a large agglomerate via hydrophobic interactions among DOXs. Although PCMB-DOX and LP-DOX showed comparable tissue permeability, pharmacokinetics, and ability to accumulate in tumor tissues, the antitumor efficacy of PCMB-DOX was better than that of LP-DOX. This was presumably due to the formation of LP-DOX agglomerates. The diffusion of cleaved DOX would be restricted in the hydrophobic core of the agglomerate, resulting in the DOX release at the tumor site being compromised. In contrast to LP-DOX, DOX release from PCMB-DOX was not compromised after accumulation in tumor tissues because it did not form such an agglomerate, resulting in the strong antitumor effect. We have demonstrated the potential of MBs as building blocks of drug carriers and believe that these findings can contribute to the design of polymer-based nanomedicines.

Surface characterization of a silicone hydrogel contact lens having bioinspired 2-methacryloyloxyethyl phosphorylcholine polymer layer in hydrated state

A silicone hydrogel contact lens material, with a unique chemical and physical structure has been designed for long-term ocular performance. Enhancement of this silicone hydrogel contact lens material was achieved through surface modification using a cross-linkable bioinspired 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, which creates a soft surface gel layer on the silicone hydrogel base material. The surface properties of this MPC polymer-modified lens were characterized under hydrated condition revealing, inter alia, its unique polymer structure, excellent hydrophilicity, lubricity, and flexibility. Analysis of the MPC polymer layer in a hydrated state was performed using a combination of a high-resolution environmental scanning electron microscopy and atomic force microscopy. Compared to the silicone hydrogel base material, this surface had a higher captive bubble contact angle, which corresponds to higher hydrophilicity of the surface. In addition, the hydrated MPC polymer layer exhibited an extremely soft surface and reduced the coefficient of friction by more than 80 %. These characteristics were attributed to the hydration state of the MPC polymer layer on the surface of the silicone hydrogel base material. Also, interaction force of protein deposition was lowered on the surface. Such superior surface properties are anticipated to contribute to excellent ocular performance.