Injectable polymers group

Fig. 3 Polymeric micelle formation of PEG-PAsp/CDDP (a), and PEG-PGlu/CDDP (b), where carboxylic groups and Pt are linked through coordination bonds, c Effect of free CDDP (left hand side) and PEG-PGlu(CDDP) micelles (right hand side) on the growth of C26 colon adenocarcinoma subcutaneously transplanted in CDFl mice (n = 10). Each drug was administrated by i. v. route five times at 2 day intervals (arrow) at the dose of 4 mg/kg CDDP eq. The molecular ratio of CDDP to the block copolymer in the micelles was calculated to be 27, and the dose of the injected polymer was 6.3 mg/kg...

In situ precipitation injectable materials are polymer solutions that precipitate when they come in contact with a non-solvent (physiological fluids) when injected into the body. Usually such polymers are hydrophobic in nature. The polymer solutions are prepared in physiologically tolerant solvents like dimethyl sulfoxide (DMSO) that are also miscible with water. Thus, when the polymer solution is injected into the body, the solvent diffuses and mixes with the physiological fluids while the polymer precipitates out to form the gel as it is not soluble in water. Major examples of this injectable material group include PCL, PLA and PLGA (poly(lactic-co-glycolic) acid) (Coombes et al., 2004, Eliaz and Kost, 2000). 

Injectable polymers used as bone scaffolds are composed of cross-linked networks, which degrade through several mechanisms. Degradation of these networks primarily relies on the nature and location of the degradable groups and cross-linkable moieties. In the case of poly(propylene fumarate) (PPF) and poly(ethylene glycol maleate citrates) (PEGMC), the cross-linkable and... 

The polymer floods are determined by two basic reservoir types confined blocks in Hankensbuettel, and reservoirs with open boundaries to an aquifer in Oerrel and Hohne. These two groups required different flood concepts. All of the polymer solutions injected in confined units could be efficiently displaced through the hydrocarbon pore volume to the producers. In other cases, it was not possible to create a uniform and continuous polymer bank, and a significant amount of injected polymer solution was lost in the aquifer and did not contribute to the targeted oil recovery. 

Alternatively, bifunctional chlorosilanes with an ether bridging group or simply sterically protected monochlorosilanes such as chlorodiisopropyloctyl silane have both provided protection of the siloxane bond between the silane and silica surface from acid hydrolysis. Using a low pH mobile phase required for the reversed-phase separation of peptides and proteins, essentially no change in column performance was observed between the first and forty-first injection. Polymers have also been cross-linked on the silica surface to form stable packings. 

The group in the Swiss Federal Institute of Technology [55] has fabricated a macroscale device by depositing the conducting polymer (poly(/j-phenylenevinylene)) on the MWCNT film (Fig. 16). They have observed the characteristic rectifying effect from the l-V curve, which suggests the CNTs inject holes efficiently into the polymer layer. However, due to the difficulty in... 

Figure 27 shows that the release rate of CBP from the polymer decreased with increasing injection-molding temperatures. Samples with decreased levels of phthalic anhydride and increased levels of the phthalate half ester erode at slower rates presumably because the phthalic acid (pKai = 2.9 and pKa2 = 5.5) is a stronger acid than its alkyl half ester (estimated pKa = 3.6) and because the concentration of acidic groups is reduced by the esterification reaction. 

---