Investigators say they’ve developed nanoparticles that can target multiple myeloma (MM) cells in the bone, as well as increase bone strength and volume to prevent MM progression.
“We engineered and tested a bone-targeted nanoparticle system to selectively target the bone microenvironment and release a therapeutic drug in a spatiotemporally controlled manner, leading to bone microenvironment remodeling and prevention of disease progression,” said study author Archana Swami, PhD, of Brigham and Women’s Hospital in Boston.
She and her colleagues described this system in Proceedings of the National Academy of Sciences.
The team developed stealth nanoparticles made of biodegradable polymers and alendronate, a therapeutic agent that belongs to the bisphosphonate class of drugs. Bisphosphonates bind to calcium and accumulate in high concentration in bones.
By coating the surface of the nanoparticles with alendronate, the investigators enabled the nanoparticles to home to bone tissue to deliver drugs encapsulated within the nanoparticles. In this way, the particles could kill tumor cells and stimulate healthy bone tissue growth.
The investigators tested their drug-toting nanoparticles in mice with MM. The mice were pretreated with nanoparticles containing the drug bortezomib, then injected with MM cells.
The treatment resulted in slower MM growth and prolonged survival. Moreover, bortezomib as a pretreatment regimen changed the make-up of bone, enhancing its strength and volume.
“These findings suggest that bone-targeted nanoparticle anticancer therapies offer a novel way to deliver a concentrated amount of drug in a controlled and target-specific manner to prevent tumor progression in multiple myeloma,” said study author Omid Farokhzad, MD, also of Brigham and Women’s Hospital.
“This approach may prove useful in treatment of incidents of bone metastasis, common in 60% to 80% of cancer patients and for treatment of early stages of multiple myeloma.”
“This study provides the proof-of-concept that targeting the bone marrow niche can prevent or delay bone metastasis,” added Irene Ghobrial, MD, of the Dana-Farber Cancer Institute in Boston.
“This work will pave the way for the development of innovative clinical trials in patients with myeloma to prevent progression from early precursor stages or in patients with breast, prostate, or lung cancer who are at high-risk to develop bone metastasis.”
