title: Towards a targeted multi-drug delivery approach to improve therapeutic efficacy in breast cancer.
abstract: BACKGROUND
  Significant improvements in breast cancer treatments have resulted in a significant decrease in mortality. However, current breast cancer therapies, for example, chemotherapy, often result in high toxicity and nonspecific side effects. Other treatments, such as hormonal and antiangiogenic therapies, often have low treatment efficacy if used alone. In addition, acquired drug resistance decreases further the treatment efficacy of these therapies. Intra-tumor heterogeneity of the tumor tissue may be a major reason for the low treatment efficacy and the development of chemoresistance. Therefore, targeted multi-drug therapy is a valuable option for addressing the multiple mechanisms that may be responsible for reduced efficacy of current therapies.
  
  
  METHODS
  In this article, different classes of drugs for treating breast cancer, the possible reasons for the drug resistance in breast cancer, as well as different targeted drug delivery systems are summarized. The current targeting strategies used in cancer treatment are discussed.
  
  
  RESULTS
  This article considers the current state of breast cancer therapy and the possible future directions in targeted multi-drug delivery for treating breast cancer.
  
  
  CONCLUSIONS
  A better understanding of tumor biology and physiological responses to nanoparticles, as well as advanced nanoparticle design, are needed to improve the therapeutic outcomes for treating breast cancer using nanoparticle-based targeted drug delivery systems. Moreover, selective delivery of multi-drugs to tumor tissue using targeted drug delivery systems may reduce systemic toxicity further, overcome drug resistances, and improve therapeutic efficacy in treating breast cancer.
authors.affiliation: Department of Mechanical Engineering, Temple University, 1947 North, 12th Street, Philadelphia, PA 19122, USA. bwang4@temple.edu
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Jenna M
authors.initials: JM
authors.lastname: Rosano
authors.forename: Rabe'e
authors.initials: R
authors.lastname: Cheheltani
authors.forename: Mohan P
authors.initials: MP
authors.lastname: Achary
authors.forename: Mohammad F
authors.initials: MF
authors.lastname: Kiani
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D004337:Drug Carriers / Q000627:therapeutic use; D004338:Drug Combinations; D016503:Drug Delivery Systems; D015195:Drug Design; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D058990:Molecular Targeted Therapy; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry / Q000627:therapeutic use; D010316:Particle Size; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D004338:Drug Combinations