Nanoparticles delivery to cancer: Approaches and limitation Hassan Tamam 1* , Jelan A. Abdel-Aleem 1 , Sayed I. Abdelrahman 1 , Aly A. Abdelrahman 1 . 1 Department of Industrial Pharmacy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt * Corresponding author: Hassan Tamam Phone: +201066078856 E-mail: Hassantamam@aun.edu.eg Abstract: Nanoparticles have received attention as promising delivery system of chemotherapy for cancer treatment. There are many mechanisms through which nanoparticles reaches the tumor site. Many nanoparticles delivery systems have been developed to solve problems associated with chemotherapeutic drugs such as solubility and stability or to increase tumor site specificity as by attachment of ligand to surface of nanoparticles. We provide a critical review about the factors affecting the delivery of nanoparticles to tumor site, mechanisms by which nanoparticles reach the tumor site, types of nanoparticles and limitation of nanomedicine. Key words: Nanoparticles; nanomedicine; cancer targeting; nanoparticles delivery systems. Introduction: Cancer is one of the worldwide deadliest disease , There is an estimated 18.1 million new cancer cases (17.0 million excluding nonmelanoma skin cancer) and 9.6 million cancer deaths (9.5 million excluding nonmelanoma skin cancer) in 2018(1). There are many advances in development of cancer therapeutics molecules. Chemotherapeutic agents are considered the major therapeutic approach for the treatment of cancer(2). However, administration of conventional anticancer drugs involves high patient risks because the drugs are not specific to cancer cells. Most patients must tolerate severe side effects, decreased quality of life, and repeated treatments. The inefficiency and side effects of chemotherapy have been primarily associated with the formulation and IJRDO - Journal of Applied Science ISSN: 2455-6653 Volume-5 | Issue-4 | April,2019 17