title: Revisiting the role of nanoparticles as modulators of drug resistance and metabolism in cancer.
abstract: BACKGROUND
  Drug resistance is the major obstacle impeding the efficacy of chemotherapeutic agents. Although numerous drug delivery techniques have been developed to combat drug resistance, their limitations of non-specific targeting and inconsistent bioavailability has led to the search of novel delivering strategies, such as nanoparticles.
  
  
  METHODS
  Nanoparticles for anti-cancer drug delivery are microscopic preparations encapsulating a chemotherapeutic and a chemosensitizer into a rationally designed drug delivery vehicle. Nano-strategies directed against multi-drug resistance (MDR) can be categorized into those inhibiting the drug efflux pumps, those effective against the cellular factors of drug resistance, and the combinational based strategies. Here, we review the most recent literature to reposition nanoparticles as chemotherapeutics and inhibitors of MDR.
  
  
  CONCLUSIONS
  Novelty in anti-cancer drug delivery has led to the formulation of chemotherapeutics and MDR inhibitors as nano-preparations, which are multi-functional and have better tumor cell-targeting effects. Their characteristics of size and surface attachments make them readily diffusible through the tumor vasculature and increase their retention time as well. With a better understanding of the molecular mechanisms of drug resistance, more potent and multi-targeted nano-preparations can be formulated in the near future.
authors.affiliation: a Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences , St. John's University , Queens , New York , USA.
authors.forename: Pranav
authors.initials: P
authors.lastname: Gupta
authors.affiliation: a Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences , St. John's University , Queens , New York , USA.
authors.forename: Khushboo A
authors.initials: KA
authors.lastname: Jani
authors.affiliation: a Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences , St. John's University , Queens , New York , USA.
authors.forename: Dong-Hua
authors.initials: DH
authors.lastname: Yang
authors.affiliation: b Department of Physics, St. John's College of Liberal Arts and Sciences , St. John's University , Queens , New York , USA.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Sadoqi
authors.affiliation: a Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences , St. John's University , Queens , New York , USA.
authors.forename: Emilio
authors.initials: E
authors.lastname: Squillante
authors.affiliation: a Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences , St. John's University , Queens , New York , USA.
authors.forename: Zhe-Sheng
authors.initials: ZS
authors.lastname: Chen
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D001682:Biological Availability; D016503:Drug Delivery Systems; D015195:Drug Design; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D053758:Nanoparticles; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D010316:Particle Size
chemical_list: D000970:Antineoplastic Agents
keywords: carriers; metabolism; modulators; multi-drug resistance; nanoparticles