in-PharmaTechnologist presents a roundup of the latest drug delivery research, including bone marrow targeting nanoparticles and an imaging-treatment combo.
Iron oxide nanoparticles loaded with chemotherapy drug doxorubicin, radioisotopes and dyes have been created to combine imaging and treatment in a single delivery vehicle.
“A close coupling of imaging and treatment within a theranostic agent and, more importantly, the data about the evolving course of an illness that these agents provide can facilitate informed decisions about modifications to treatment”, the researchers write in Molecular Pharmaceutics .
In tests on mice the formulation had a similar therapeutic impact to commercially available Doxil (doxorubicin HCl liposome injection). However, there was less accumulation around the heart and this could mean higher doses can be administered without serious side effects.
Nanotechnology-based delivery carriers are being researched as vehicles for delivering drugs to bone marrow. Microspheres can passively target bone marrow but research in Advanced Materials claims nanotech delivery carriers can hone in on cell-adhesion molecules found in the tissue.
Therapeutic nanoparticles are loaded into porous silicon microparticles that use a ligand to actively target the bone marrow. The drug is released as the silicon is broken down under conditions found in bone marrow.
Uses for the system extend beyond therapeutic delivery. “This delivery platform can also be utilised to deliver imaging agents and growth factors such as colony stimulating factor (CSF) for the protection of bone marrow against chemotherapy and radiation”, the researchers write.
Lipid substitution on low molecular weight polyethylenimine (PEI) has been proposed as a means to create short interfering RNA (siRNA) delivery systems that lack the toxicity, but keep the efficacy, of heavier variants.
Survivin, a protein involved in cell survival, was targeted to induce apoptosis in breast cancer cells. At concentrations shown to be effective for silencing survivin modified low molecular weight PEI has minimal toxicity, researchers write in Molecular Pharmaceutics .