Encapsulated vaccine more effective than vaccine suspensions for reducing tumor burden.(Brief Article)

2002 JUN 12 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - When used preoperatively or early postoperatively for murine colorectal cancer, an encapsulated whole-cell plus adjuvant vaccine significantly reduced tumor volume, say investigators from New York.

"The use of perioperative vaccines may prove to be an effective way to immunize patients with cancer undergoing surgery," said I. Kirman and colleagues at Columbia University in New York City.

Autologous colon cancer vaccines combined with an adjuvant such as monophosphoryl lipid A are used to reduce tumor volume after surgery for colorectal cancer. Timing vaccine delivery to achieve the greatest benefit can be difficult. Preoperative delivery can limit the effectiveness of the vaccine due to surgery-related immunosuppression. Use of the vaccine several weeks after surgery allows any remaining cancer cells to become established.

To overcome these challenges, Kirman and colleagues encapsulated ultraviolet-irradiated C26 colon cancer cells and monophosphoryl lipid A into alginate beads. Encapsulating the vaccine could extend time of exposure to the vaccine and slow tumor growth.

Investigators tested two vaccine formulations, a standard liquid formulation and the encapsulated vaccine. Syngeneic BALB/c mice were inoculated, and 2 weeks later the tumors were excised and tumor volume measured (Combined whole tumor cell and monophosphoryl lipid A vaccine improved by encapsulation in murine colorectal cancer, Surgical Endoscopy and Other Interventional Techniques, 2002;16(4):654-658).

Mice ...