title: Nanodrug-enhanced radiofrequency tumor ablation: effect of micellar or liposomal carrier on drug delivery and treatment efficacy.
abstract: OBJECTIVE
  To determine the effect of different drug-loaded nanocarriers (micelles and liposomes) on delivery and treatment efficacy for radiofrequency ablation (RFA) combined with nanodrugs.
  
  
  METHODS
  Fischer 344 rats were used (n = 196). First, single subcutaneous R3230 tumors or normal liver underwent RFA followed by immediate administration of i.v. fluorescent beads (20, 100, and 500 nm), with fluorescent intensity measured at 4-24 hr. Next, to study carrier type on drug efficiency, RFA was combined with micellar (20 nm) or liposomal (100 nm) preparations of doxorubicin (Dox; targeting HIF-1α) or quercetin (Qu; targeting HSP70). Animals received RFA alone, RFA with Lipo-Dox or Mic-Dox (1 mg i.v., 15 min post-RFA), and RFA with Lipo-Qu or Mic-Qu given 24 hr pre- or 15 min post-RFA (0.3 mg i.v.). Tumor coagulation and HIF-1α or HSP70 expression were assessed 24 hr post-RFA. Third, the effect of RFA combined with i.v. Lipo-Dox, Mic-Dox, Lipo-Qu, or Mic-Qu (15 min post-RFA) compared to RFA alone on tumor growth and animal endpoint survival was evaluated. Finally, drug uptake was compared between RFA/Lipo-Dox and RFA/Mic-Dox at 4-72 hr.
  
  
  RESULTS
  Smaller 20 nm beads had greater deposition and deeper tissue penetration in both tumor (100 nm/500 nm) and liver (100 nm) (p<0.05). Mic-Dox and Mic-Qu suppressed periablational HIF-1α or HSP70 rim thickness more than liposomal preparations (p<0.05). RFA/Mic-Dox had greater early (4 hr) intratumoral doxorubicin, but RFA/Lipo-Dox had progressively higher intratumoral doxorubicin at 24-72 hr post-RFA (p<0.04). No difference in tumor growth and survival was seen between RFA/Lipo-Qu and RFA/Mic-Qu. Yet, RFA/Lipo-Dox led to greater animal endpoint survival compared to RFA/Mic-Dox (p<0.03).
  
  
  CONCLUSIONS
  With RF ablation, smaller particle micelles have superior penetration and more effective local molecular modulation. However, larger long-circulating liposomal carriers can result in greater intratumoral drug accumulation over time and reduced tumor growth. Accordingly, different carriers provide specific advantages, which should be considered when formulating optimal combination therapies.
authors.affiliation: Laboratory for Minimally Invasive Tumor Therapies, Department of Radiology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, United States of America.
authors.forename: Marwan
authors.initials: M
authors.lastname: Moussa
authors.affiliation: Laboratory for Minimally Invasive Tumor Therapies, Department of Radiology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, United States of America; Division of Image-guided Therapy and Interventional Oncology, Department of Radiology, Hadassah Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: S Nahum
authors.initials: SN
authors.lastname: Goldberg
authors.affiliation: Laboratory for Minimally Invasive Tumor Therapies, Department of Radiology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, United States of America.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Kumar
authors.affiliation: Department of Pharmaceutical Sciences and Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, United States of America.
authors.forename: Rupa R
authors.initials: RR
authors.lastname: Sawant
authors.affiliation: Department of Pharmaceutical Sciences and Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, United States of America.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Levchenko
authors.affiliation: Department of Pharmaceutical Sciences and Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, United States of America.
authors.forename: Vladimir P
authors.initials: VP
authors.lastname: Torchilin
authors.affiliation: Laboratory for Minimally Invasive Tumor Therapies, Department of Radiology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, United States of America.
authors.forename: Muneeb
authors.initials: M
authors.lastname: Ahmed
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage*; D017115:Catheter Ablation; D059248:Chemoradiotherapy; D004317:Doxorubicin / Q000008:administration & dosage*; D005260:Female; D008081:Liposomes; D008823:Micelles; D053758:Nanoparticles; D010316:Particle Size; D011794:Quercetin / Q000008:administration & dosage; D011916:Rats, Inbred F344; D023041:Xenograft Model Antitumor Assays
chemical_list: D000903:Antibiotics, Antineoplastic; D008081:Liposomes; D008823:Micelles; D004317:Doxorubicin; D011794:Quercetin