title: Therapeutic effects of acoustic cavitation in the presence of gold nanoparticles on a colon tumor model.
abstract: OBJECTIVE
  Acoustic cavitation can be fatal to cells and is used to destroy cancerous tumors. The particles in a liquid decrease the ultrasonic intensity threshold needed for onset of cavitation. Bubble generation from intense pulsed light-irradiated gold nanoparticles was investigated as a means of providing nucleation sites for acoustic cavitation in cancer tissues.
  
  
  METHODS
  This study was conducted on colon carcinoma tumors in BALB/c mice. The tumor-bearing mice were randomly divided into 7 groups (each containing 15 mice): (1) control, (2) gold nanoparticles, (3) intense pulsed light irradiation, (4) intense pulsed light + gold nanoparticles, (5) ultrasound alone, (6) ultrasound + gold nanoparticles, and (7) intense pulsed light + ultrasound + gold nanoparticles. In the respective groups, gold nanoparticles were injected into tumors. Intense pulsed light and ultrasound irradiation were performed on the tumors 24 hours after injection. Antitumor effects were estimated by evaluation of the relative tumor volume, doubling time, and 5-folding time for tumors after treatment. The cumulative survival fraction of the mice and percentage of the lost tissue volume (treated) were also assessed in different groups.
  
  
  RESULTS
  A significant difference in the average relative tumor volumes 15 days after treatment was found between the intense pulsed light + ultrasound + gold nanoparticle group and the other groups (P < .05). The longest doubling and 5-folding times were observed in the intense pulsed light + ultrasound + gold nanoparticles and ultrasound + gold nanoparticle groups.
  
  
  CONCLUSIONS
  Acoustic cavitation in the presence of gold nanoparticles and intense pulsed light has been introduced as a new way for improving therapeutic effects on tumors by reducing the relative tumor volume and increasing the cumulative survival fraction.
authors: Research Center and Department of Medical Physics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors: Ameneh
authors: A
authors: Sazgarnia
authors: Ahmad
authors: A
authors: Shanei
authors: Ahmad Reza
authors: AR
authors: Taheri
authors: Naser Tayyebi
authors: NT
authors: Meibodi
authors: Hossein
authors: H
authors: Eshghi
authors: Neda
authors: N
authors: Attaran
authors: Mohammad Mahdi
authors: MM
authors: Shanei
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D003131:Combined Modality Therapy; D006046:Gold / Q000627:therapeutic use*; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods*; D008297:Male; D053768:Metal Nanoparticles / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D006046:Gold