Shinichi Ohta MD, Presenter: Nothing to Disclose

Norihisa Nitta MD, Abstract Co-Author: Nothing to Disclose

Masashi Takahashi MD, Abstract Co-Author: Nothing to Disclose

Akinaga Sonoda MD, Abstract Co-Author: Nothing to Disclose

Kiyoshi Murata MD, Abstract Co-Author: Nothing to Disclose

Yasuhiko Tabata, Abstract Co-Author: Nothing to Disclose

Toyohiko Tanaka MD, Abstract Co-Author: Nothing to Disclose

Akira Furukawa MD, Abstract Co-Author: Nothing to Disclose

Shigehiro Morikawa MD, PhD, Abstract Co-Author: Nothing to Disclose

Toshiro Inubushi PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To develop cisplatin-eluting, degradable gelatin microspheres(CE-GMSs) and confirm eluting event in vivo and assess the anti-tumor effects for VX2 liver tumors in rabbits.

1. Preparation of CE-GMSs (1)Cisplatin(Pt) was immersed in gelatin microspheres(GMSs) and freeze-dried; (2)the product of (1) was rinsed with distilled water and freeze-dried; steps (1) and (2) were repeated 5 times. Cisplatin concentrations(CC) in GMSs were measured. 2. In vivo elution study CE-GMSs of 2mg/kg(Pt:0.04mg/kg) were used for transarterial chemoembolization(TACE) on the right renal artery(rRA)(n=3). As a control, Pt(0.04mg/kg) was used for transarterial infusion(TAI) on the rRA(n=3). CC in the blood and bilateral renal parenchyma were measured immediately after the procedure, on the days 1, 3, and 7. 3. Anti-tumor study Before TACE and transarterial embolization(TAE) for VX2 liver tumors, tumor volumes were analyzed by using MRI. Subsequently, CE-GMSs of 2mg/kg(Pt:0.04mg/kg) were used for TACE on the hepatic artery(HA)(n=3). As controls, saline(n=3), and Pt(1.5mg/kg)(n=3) were infused into the HA, and GMSs(2mg/kg)(n=3) were used for TAE on the HA. On the 7th day after the procedure, tumor volumes were analyzed again and the relative tumor growth rate was calculated.

1. Repetition of the immersion procedure increased the binding rate of Pt to GMSs. 2. CC of the right renal parenchyma (drug infused side) were higher in TACE than TAI. 3. CC of the left renal parenchyma (not infused side) were higher in TACE than TAI except immediately after the procedure. 4. CC in the blood were detected until only 5 min following the procedure. 5. The relative tumor growth rate of CE-GMSs, saline, Pt and GMSs were 0.80±0.36, 4.57±1.17, 3.04±0.82, 3.07±1.50, respectively.

CE-GMSs were proven to have the Pt-eluting function in addition to the embolizing effect. Their properties are beneficial in reducing Pt doses and prolonging exposure time of Pt to the tumor cells.

If CE-GMSs of various sizes and degradation periods are commercially available, a customized TACE procedure can be designed by changing the level of occlusion, as well as, the release rate of Pt.

Ohta, S, Nitta, N, Takahashi, M, Sonoda, A, Murata, K, Tabata, Y, Tanaka, T, Furukawa, A, Morikawa, S, Inubushi, T, et al, , Cisplatin-Eluting Degradable Gelatin Microspheres: Experimental Study Using Rabbits.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4430688.html