Targeted Delivery and On-demand Release of Cancer Drugs

 Drug administration process for cancer treatment was always a challenge. In 2007, cancer cause about 7.9 million deaths worldwide (13% deaths). Currently, about 12.5 million new cases of cancer are being diagnosed each year worldwide and substantial research is progress for discovering the ultimate drug for curing cancer. Cancer drug delivery is no longer simply wrapping up cancer drugs in new formulations for different routes of delivery. Presently, we should focus on targeted drug delivery mechanism.  Drug delivery mechanisms play a major role in delivering drugs very efficiently to target the infected cells on demand. The newer approaches to cancer treatment not only supplement the conventional chemotherapy and radiotherapy but also prevent damage to normal tissues, prevent drug resistance and can be administrated on demand.

Currently, molecular biology concepts such as: targeting of cyclic-dependent kinases, antiangiogenic agents, immunotherapy, antiangiogenic agents, bacterial agents, viral oncolysis, tyrosine kinase receptors, gene therapy and combination of various methods are being used as an innovative cancer therapies.

Numerous innovative methods of drug delivery are used in cancer. These include use of microparticles and nanoparticles as carriers of anticancer agents. These may be injected into the arterial circulation and guided to the tumor by magnetic field for targeted drug delivery. Polyethylene glycol (PEG) technology has been used to overcome some of the barriers to anticancer drug delivery. Encapsulating anticancer drugs in liposomes enables targeted drug delivery to tumor tissues and prevents damage to the normal surrounding tissues. Monoclonal antibodies can be used for the delivery of anticancer payloads such as radionucleotides, toxins and chemotherapeutic agents to the tumors.

Antisense oligonucleotides have been in clinical trials for cancer for some time now. RNAi has also been applied in oncology. Small interfering RNAs (siRNAs) can be targeted to tumors and one example is suppression of H-ras gene expression indicating the potential for application in therapy of ovarian cancer. Cancer gene therapy is a sophisticated form of drug delivery for cancer. Various technologies and companies developing them are described. Nucleic acid-based cancer vaccines are also described.

Drug delivery strategies vary according to the type and location of cancer. Role of drug delivery in the management of cancers of the brain, the bladder, the breast, the ovaries and the prostate are used as examples to illustrate different approaches both experimental and clinical. Biodegradable implants of carmustine are already used in the treatment of malignant brain tumors.

Currently, we are developing a state of art very efficient drug delivery method: According to our invented ME nanotechnology (patent pending), DC and AC external magnetic fields (by miniaturized coil chips) are used for the purposes of speedy delivery of the drug bound nanocarrier and on demand drug release, respectively. Consequently, such low-energy-consumption requirements enable an extreme portability of the device implementation.