Development of polymer and lipid based nano-delivery systems for targeted cancer chemotherapy

• Author / Creator

  Shahin, Mostafa H

• Conventional chemotherapy agents can kill tumor cells and inhibit tumor growth, but they produce severe side effects on normal cells at the same time. To shift the balance towards tumoral effects, it would be desirable to direct the anti-cancer drug towards tumor while restricting drug access to normal tissues. The main objective of this thesis was to develop tumor targeted drug delivery system that can take on this task and as a result, improve the specificity and anticancer activity of the incorporated anticancer drugs towards tumor. To this end, lipid and block copolymer based nano-delivery systems of two conventional anti-cancer agents doxorubicin (DOX) and paclitaxel (PTX) are developed, respectively, and modified on their surface with a 12mer breast tumor interacting peptide, namely p160, or its engineered derivatives developed in our research team. The effect of peptide decoration on the specific interaction as well as anti-cancer activity of developed nano-formulations against human breast tumor cells over normal epithelial breast cells or endothelial cells was characterized, in vitro. In this study, micelles of poly(ethylene oxide)-b-poly(-caprolactone) were prepared and modified with either c(RGDfK) or p160 and loaded with paclitaxel (PTX). Peptide decoration enhanced the selective cytotoxicity of encapsulated PTX against cancer cells over normal cells. The extent of this increase in cancer cell specificity for encapsulated PTX was more for p160-modified micelles. At the end, the anti-cancer activity of liposomal formulations of DOX, having different density of an engineered breast tumor targeting peptide, namely p-18-4, was assessed in vitro for cellular uptake and selective cytotoxicity, and in vivo using animal model of human breast tumor xenograft and compared to that for liposomal formulations of DOX with no peptide decoration. Liposomal DOX formulations bearing low p18-4 density showed better in vitro selective cytotoxicity and in vivo therapeutic efficacy. Our results points to the potential of p160 and its engineered derivatives as efficient ligands on lipid and block copolymer based nanocarriers for active targeting of anticancer agents to breast tumors. The results also show the success of this strategy in enhancing the specific anti-cancer effects of the incorporated drug against breast tumor models.

• Subjects / Keywords

  • Peptides
  • Liposomes
  • Polymeric micelles
  • Chemotherapy

• Graduation date

  Fall 2012

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3VT1GZ32

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.