Tumor cells micelles

As a result of this pH-dependent stability, the PHis-PEG micelles loaded with DOX exhibited a pH-dependent drug release. DOX was released faster at pH lower than 7.0 than at pH 7.4 and 8.0 (Fig. 10.5) [143]. It was hypothesized that PHis-PEG micelles were destabilized in a slightly acidic environment and hence released the DOX into the extracellular medium for enhanced drug permeation into the tumor cells due to high concentration gradients. The in vitro cytotoxicity was tested... 

Du Y-Z, Wang L et al (2011) Linoleic acid-grafted chitosan oligosaccharide micelles for intracellular drug delivery and reverse drug resistance of tumor cells. Int J Biol Macromol 48(l) 215-222... 

In our SMA micelles of pirarubicin or doxorubicin constant release of the anthracycline from micelles was observed, the rate was much slower than the endocytotic process, which showed a release rate of 4-5%/day. In these cases, once the micelles are taken up into the tumor cells, active principle of free drugs will be continuously released. However, pirarubicin, which exhibits higher... 

Fig. 7 Schematic model for the proposed drug delivery system consists of two components, a PLLA-h-PEG micelle conjugated to TAT and a pH-sensitive diblock polymer PSD-i-PEG. (a) At normal blood pH, the sulfonamide is negatively charged, and when mixed with the TAT micelle, it shields the TAT by electrostatic interaction. Only PEG is exposed to the outside, which could make the carrier long circulating (b) when the system experiences a decrease in pH (near tumor), sulfonamide loses charge and detaches, thus exposing TAT for interaction with tumor cells (adapted from Ref [199] with permission)...

Zhao, H.Z., Yung, L.Y.L., 2008. Selectivity of folate conjugated polymer micelles against different tumor cells. Int. J. Pharm. 349, 256—268. 

Redox-responsive nanovehicles containing disulfide bonds have been reported. Biodegradable multiblock PUs bearing varied amounts of disulfide linkages were synthesized. The reducible PUs exhibited appropriate phase behavior and self-assembly properties. It was also found that the redox-sensitive PU micelles could rapidly enter tumor cells and can transport the encapsulated pacUtaxel effectively (Figure 8.9). The inhibition effects were controlled by adjusting the disulfide content in the polymeric backbone [96]. 

Recently, a novel vaccine concept based on nanosized polymer-linked vaccines, has been explored. In particular tumor-associated MUCl glyco-peptides and T-cell epitope peptides were coupled to watersoluble methacrylamide polymers the subsequent attachment of the tetanus toxoid T-cell epitope P2 onto the hydrophilic polymer vaccines, causes their self-assembly to micelle-like nanoobjects. These novel polymer-based glycopeptide vaccines induced significant MHC-II-mediated immune reactions in mice and elicit IgG antibodies, which recognize breast tumor cells. 

In this chapter, we would like to introduce PIC micelles encapsulating ionic dendrimer porphyrins as a photosensitiser (PS) for photodynamic therapy (PDT). PDT is a topical therapeutic modality of malignant tumors, which treats tumor cells with cytotoxic singlet oxygen ( O2) produced by PS through photo-excitation at its characteristic wavelength A successful PDT may be completed by the development of potent PSs their tumor-selective delivery and selective and effective photoirradiation at the... 

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