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Solid Lipid Nanoparticles for Anti-Tumor Drug Delivery
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
Ho Lun Wong, Yongqiang Li, Reina Bendayan, Mike Andrew Rauth, Xiao Yu Wu
Camptothecin is a plant alkaloidal compound extracted from Camptotheca acuminata.92 It serves as the prototype compound of a relatively new class of anti-tumor agents known as topoisomerase I inhibitors (e.g., irinotecan, topotecan). The molecules of camptothecin and its related compounds all possess extensive aromatic structures and are quite lipophilic (Figure 36.12a).93 The anti-tumor activity of camptothecin is strongly correlated to the functionality of the lactone ring of the drug molecule. However, in an aqueous environment, particularly at basic pH, this lactone ring is vulnerable to hydrolysis, leading to the formation of therapeutically inactive carboxylate. The poor water solubility and chemical stability of this drug has seriously diminished its practical value. These two shortcomings can both be overcome by the use of SLN for their capabilities to efficiently load lipophilic compounds and provide a lipid environment to prevent hydrolytic degradation. Yang et al.79 described a SLN system for camptothecin delivery. A very high encapsulation efficiency (99.6%) of camptothecin was achieved. The same study also showed that the drug mostly remained in its active lactone form until it was released, confirming the protective effect of SLN against hydrolytic degradation.
Herbs in Cancer Therapy
Published in Anil K. Sharma, Raj K. Keservani, Surya Prakash Gautam, Herbal Product Development, 2020
Annum Malik, Shahzadi Sidra Saleem, Kifayat Ullah Shah, Learn-Han Lee, Bey Hing Goh, Tahir Mehmood Khan
Camptothecin is a phytoalkaloid—discovered in a Chinese tree called Camptotheca acuminate. Topotecan and irinotecan are chemical analogs of camptothecin, currently under clinical trials for use in combination therapy or alone in a variety of cancers. They are FDA approved and are used for the treatment of ovarian cancer, small cell lung, and metastatic colorectal cancer (Chauhan et al. 2015).
PEGylated liposomes: immunological responses
Published in Science and Technology of Advanced Materials, 2019
Marwa Mohamed, Amr S. Abu Lila, Taro Shimizu, Eman Alaaeldin, Amal Hussein, Hatem A. Sarhan, Janos Szebeni, Tatsuhiro Ishida
Recent reports have demonstrated that multiple injections of PEGylated liposomes containing topotecan in beagle dogs and Wistar rats could trigger the ABC phenomenon [72,73]. Topotecan is a cell cycle-specific drug that exerts its inhibitory action in the S phase of the cell cycle. One can hypothesize that topotecan might not affect the B cell proliferation for B cells in other phases of the cell cycle and still allow them to produce some anti-PEG IgM. Another, more convincing hypothesis is that the rapid release of topotecan from liposomes could result in empty (drug-free) liposomes or drug-depleted liposomes in the blood circulation. The interaction of such drug-free or drug-depleted liposomes with the B cells in spleen could induce the production of anti-PEG IgM, rather than inhibiting its production, and lead to the induction of the ABC phenomenon upon repeated intravenous administration [73].