Israel Medical Association Journal

Background: Several in vitro studies have reported on the efficacy of combined liposomal encapsulated doxorubicin (Doxil® or Caelyx®, MedEquip, UK) and hyperthermia over Doxil alone.

Objectives: To document the beneficial effect of Doxil-HT over Doxil alone in mice and to investigate the length of time HT[1] should be delivered.

Methods: M/109 lung tumor cells were injected into both leg pads of Balb/c female mice at age of 6–7 weeks. Two weeks later i.v. Doxil in a dose of 8 mg/kg (20–25 µg per mouse) was given and 4 HT sessions (2–3 days apart) were delivered during the subsequent 2 weeks at 2–3 days apart. HT was given to the left pad only for either 5 or 30 minutes (HT5 and HT30 respectively). Five weeks after tumor injection the mice were sacrificed and tumor volume and weight in both pads were measured. Internal comparisons between mice in the same treatment group and comparisons between different treatment cohorts were performed.

Results: In the combined Doxil-HT5 and Doxil-HT30 cohorts the tumor volume and weight in both pads were similar and did not differ from those achieved by Doxil alone. In the Doxil-HT30 cohort the tumor weight, but not the tumor volume, were smaller than those in Doxil-HT5 and Doxil alone (P = 0.006 and 0.01 respectively).

Conclusions: The combined Doxil-HT30 treatment is more effective then Doxil-HT5 or Doxil alone. Additional studies with different time scheduling and different temperatures are warranted.

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[1] HT = hyperthermia

Red cell substitutes are currently under development for use in a variety of surgery and trauma-related clinical conditions. The need for artificial oxygen-carrying fluids continues to be driven by the shortage of donor blood, the complex logistics of blood banking, the risk of virally transmitted diseases, current transfusion practices, and the projected increased demand for blood products in the future. The effort to develop a replacement for the red cell component has evolved over the last century and has presented a number of significant challenges including safety and efficacy concerns. Recent progress in understanding the fundamental interactions of hemoglobin with the body at the molecular, cellular and tissue levels has led to the production of improved red cell substitutes suitable for clinical testing. Currently, seven products are being tested for a variety of applications including trauma, surgery, sepsis, cancer and anemia. Although some of these trials were unsuccessful, the majority of the available products exert no toxicity or only low level side effects. Encouraging results in early clinical trials with oxygen-carrying fluids support further development of these products and have increased the hope that a usable oxygen-carrying fluid will soon be available in the clinic. The purpose of this review is to provide up-to-date information on the status of these products with special emphasis on pre-clinical and clinical experience.