muramidase and 2-methacryloyloxyethyl-phosphorylcholine

Silicone hydrogel contact lenses (CLs) permit increased oxygen permeability through their incorporation of siloxane functional groups. However, contact lens biofouling can be problematic with these materials; surface modification to increase lens compatibility is necessary for acceptable properties. This work focuses on the creation of an antifouling CL surface through a novel grafting method. A polymer incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC), well known for its antifouling and biomimetic properties, was grafted to the model lens surfaces using surface-initiated atom transfer radical polymerization (SI-ATRP). The SI-ATRP modification generated a unique double-grafted polymeric architecture designed to resist protein adsorption through the presence of a surrounding hydration layer due to the PC groups and steric repulsion due to the density of the grafted chains. The polymer was grafted from model silicone hydrogel CL using a four-step SI-ATRP process. Attenuated total reflectance-Fourier transform infrared spectroscopy and XPS were used to confirm the surface chemical composition at each step of the synthesis. Both the surface wettability and equilibrium water content of the materials increased significantly upon polyMPC modification. The surface water contact angle was as low as 16.04 ± 2.37° for polyMPC-50 surfaces; complete wetting (∼0°) was observed for polyMPC-100 surfaces. A decrease in the protein adsorption by as much as 83% (p < 0.000 36) for lysozyme and 73% (p < 0.0076) for bovine serum albumin was observed, with no significant difference between different polyMPC chain lengths. The data demonstrate the potential of this novel modification process for the creation of extremely wettable and superior antifouling surfaces, useful for silicone hydrogel CL surfaces.

Topics: Adsorption; Animals; Biofouling; Cattle; Hydrogels; Methacrylates; Muramidase; Phosphorylcholine; Plasma Gases; Polymers; Serum Albumin, Bovine; Silicones; Surface Properties; Wettability

In this work, 2-methacryloyloxyethyl phosphorylcholine (MPC) was used as a ligand to prepare a novel mixed-mode chromatography (MMC) stationary phase by the thiol-ene click reaction onto silica (MPC-silica). It was found that this MPC-silica showed the retention characteristics of hydrophilic interaction chromatography (HILIC) and weak cation exchange chromatography (WCX) under suitable mobile phase conditions. In detail, acidic and basic hydrophilic compounds and puerarin from pueraria were separated quickly with HILIC mode. Meanwhile, six standard proteins were allowed to reach baseline separation in WCX mode, and protein separation from egg white was also achieved with this mode. In addition, reduced/denatured lysozyme could be refolded with the MPC-silica column. In the meantime, the MPC-silica has been applied for refolding with simultaneous purification of recombinant human Delta-like1-RGD (rhDll1-RGD) expressed in Escherichia coli. The results show that the mass recovery and purity of rhDll1-RGD could reach 63.4% and 97% by one step, respectively. Furthermore, the reporter assay results demonstrated that refolded with simultaneously purified rhDll1-RGD could efficiently activate the signalling pathway in a dose-dependent manner. In general, this MPC-silica has good resolution and selectivity in the separation of polar compounds and protein samples in different high-performance liquid chromatography (HPLC) modes, and it successfully achieved refolding with simultaneous purification of denatured protein.

Topics: Calcium-Binding Proteins; Cations; Chromatography, Ion Exchange; Egg White; Humans; Hydrophobic and Hydrophilic Interactions; Intercellular Signaling Peptides and Proteins; Ligands; Membrane Proteins; Methacrylates; Muramidase; Phosphorylcholine; Photoelectron Spectroscopy; Protein Denaturation; Protein Folding; Recombinant Proteins; Reference Standards; Silicon Dioxide

In order to develop a simple, economical and rapid approach to incorporate 2-methacryloyloxyethyl phosphorylcholine (MPC) with other monomers without any solvent, we prepared a series of ultraviolet cured poly(urethane acrylate) (PUA) membranes containing different MPC content. Their chemical structure and surface properties were investigated by FT-IR, XPS, water swelling ratio and water contact angle measurement, while the biocompatibilities were evaluated through fibrinogen adsorptions, platelet adhesion and plasma recalcification time determination. The results demonstrate that the phosphorylcholine (PC) groups were successfully introduced into the PUA system by the UV-curing approach and the all PC-containing membranes showed better biocompatibility than those without PC moiety. The UV-curing method is potentially to be applied in the coating of medical devices which require biocompatibility and manufacturing efficiency.

Topics: Acrylic Resins; Calcification, Physiologic; Fibrinogen; Humans; Hydrophobic and Hydrophilic Interactions; Materials Testing; Membranes, Artificial; Methacrylates; Molecular Structure; Muramidase; Phosphorylcholine; Plasma; Platelet Adhesiveness; Polyurethanes; Solvents; Surface Properties; Ultraviolet Rays; Water