PHEMA methacrylate

Interpenetrating networks (IPNs) composed of different proportions of PCL and poly-2-hydroxyethyl methacrylate (pHEMA) have... 

Simple physical entanglements can be sufficient to produce a structurally stable gel if the polymer has a sufficiently great molecular weight and if the polymer is of only modest hydrophilicity. In this case, the polymer will swell in water without dissolving, even in the absence of covalent cross-links. Poly(2-hydroxyethyl methacrylate) (PHEMA) is a prominent example of this type of hydrogel when uncross-linked, it will dissolve in 1,2-propanediol but only swell in water. 

It is possible for Q or q to range from 1.2 to over 1000 this translates to an EWC range of 20% to over 99%. A commonly used hydrogel for drug delivery, poly(2-hydroxyethyl methacrylate) (PHEMA), has a q of about 1.7 or an EWC of about 40%. 

Polymeric particles can be constructed from a number of different monomers or copolymer combinations. Some of the more common ones include polystyrene (traditional latex particles), poly(styrene/divinylbenzene) copolymers, poly(styrene/acrylate) copolymers, polymethylmethacrylate (PMMA), poly(hydroxyethyl methacrylate) (pHEMA), poly(vinyltoluene), poly(styrene/butadiene) copolymers, and poly(styrene/vinyltoluene) copolymers. In addition, by mixing into the polymerization reaction combinations of functional monomers, one can create reactive or functional groups on the particle surface for subsequent coupling to affinity ligands. One example of this is a poly(styrene/acrylate) copolymer particle, which creates carboxylate groups within the polymer structure, the number of which is dependent on the ratio of monomers used in the polymerization process. 

Poly(2-hydroxyethyl methacrylate) (PHEMA) has been the most widely used polymer in drug delivery applications. It is an extremely hydrophilic... 

PEG, 13 736-737 pH-sensitive, 13 743 PHEMA, 13 733-734, 749, 750 poly(acrylamide)-based, 13 737-738 poly(acrylic/methacrylic acid), 13 734 poly(N-vinyl 2-pyrrolidone), 13 739 polyurethane, 13 739 porous, 13 750-751 preparation methods for, 13 731-732 properties and preparation of,... 

An NIR optical fiber for the detection of metal ions has been developed In a controlled environment, the optical probe with immobilized NIR dye was immersed in vials containing different metal ions varying in concentrations from 10 9 to 1CT2 M. The probe response was obtained by the diffusion of the metal ions through the poly(2-hydroxyethyl methacrylate) (PHEMA) polymer matrix where the dye was covalently attached. On complexation of the metal with the dye, the intensity of the fluorescence signal increased. 

Fig. 11 Chemical formulas of poly(acryl amide) (PAAm), poly(methyl methacrylate) (PMMA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(t-butyl acrylate) (PtBA), and poly(acrylic acid) (PAA), and poly(dimethyl aminoethyl methacrylate) (PDMAEMA)...

Fig. 43 Dry thickness of poly(2-hydroxyethyl methacrylate) (PHEMA) as a function of the position on the substrate (lower panel). The fluorescence microscopy images show the corresponding structure of fibrinogen at three positions along the PHEMA gradient (upper panel). (Reproduced with permission from [164])...

Polyhydroxyethyl methacrylate (phema) is more soluble in water than polymethyl methacrylate (PMMA). Cross-linked phema, which swells but does not dissolve in water, is used in soft contact lenses. 

Fig. 8. R/Platelet in individual platelets adhering to polymer surfaces. HSB data were statistically confirmed to be different from PSt (P < 0.5), HSR (P < 0.5) and PHEMA (P < 0.5) after 40 s R/Platelet (an index of cytoplasmic free calcium concentration) is the ratio of fluorescence emission intensitie of a Ca2 + indicator dye (Fura 2) loaded in platelets when they are excited at 340 nm and 380 nm. (Reproduced from J Biomed Mater Res [Ref 84 Prevention of changes in platelet cytoplasmic free calcium levels by interaction with 2-hydroxyethyl methacrylate/styrene block copolymer surfaces] through the courtesy of John Wiley Sons, Inc.)...

Fig. 15. Effect of the diluent volume fraction on the temperature of the T and T d dispersions of poly(2-hydroxyethyl methacrylate) Ethylene glycol (—, O) formamide (-.-, 3) water (—, ) propanol (..., >). The curves have been calculated according to Eq. (13), for the system PHEMA-water drawn through experimental points...

Hydrogels Hydrogels consist of a cross-linked polymer system or a meshlike structure that is flexible and can swell in the presence of water, producing a hydrophilic surface and masking the components below. The most widely used hydrogels consist of poly(hydroxyethyl methacrylate) (PHEMA), poly(ethylene glycol) (PEG), or poly(vinyl alcohol) (PVA) and tend to have reduced interaction with tissue.22 31 44 53 55... 

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