title: Recent advances in the design of drug-loaded polymeric implants for the treatment of solid tumors.
abstract: BACKGROUND
  The effective treatment of solid tumors continues to be a great challenge to clinicians, despite the development of novel drugs. In order to improve the clinical efficacy of existing chemotherapeutic agents, researchers have considered the possibility of site-specific solid tumor treatment. The greatest advantage of localized delivery is the significantly fewer side effects experienced by patients. Recently, in situ forming implants have attracted considerable interest. These polymeric systems are injected as solutions into tumor sites and the injected solution forms an implant as a result of local environmental stimuli and hence removes the need for surgical implantation.
  
  
  METHODS
  This review summarizes the attempts that have been made to date in the development of polymeric implants for the treatment of solid tumors. Both in situ forming implants and preformed implants, fabricated using natural and synthetic polymers, are described. In addition, the peri- or intra-tumoral delivery of chemotherapeutic agents based on implants inserted surgically into the affected region is also discussed along with a short coverage of implants having an undesirable initial burst release effect.
  
  
  CONCLUSIONS
  Although these implants have been shown to improve the treatment of various solid tumors, the ideal implant that is able to deliver high doses of chemotherapeutics to the tumor site, over prolonged periods with relatively few side effects on normal tissue, is yet to be formulated.
authors.affiliation: University of the Witwatersrand, Department of Pharmacy and Pharmacology, Parktown, 2193, Johannesburg, South Africa.
authors.forename: Ameena
authors.initials: A
authors.lastname: Wadee
authors.forename: Viness
authors.initials: V
authors.lastname: Pillay
authors.forename: Yahya E
authors.initials: YE
authors.lastname: Choonara
authors.forename: Lisa C
authors.initials: LC
authors.lastname: du Toit
authors.forename: Clement
authors.initials: C
authors.lastname: Penny
authors.forename: Valence M K
authors.initials: VM
authors.lastname: Ndesendo
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kumar
authors.forename: Caragh S
authors.initials: CS
authors.lastname: Murphy
mesh_terms: D020341:Absorbable Implants; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy*; D011108:Polymers / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D011108:Polymers