Chinese researchers have developed nanoparticles to treat a more aggressive type of breast cancer.

Human epidermal growth factor 2 (HER2) is a type of protein in the breast tissue, helping control breast cells to divide, grow and repair. When the HER2 gene is abnormal, it encourages the rapid growth of cancer cells.

Around 20 to 30 percent of breast cancer patients have an abnormal expression of HER2 gene. The HER2 positive breast cancer tends to grow faster, spread more easily and be more likely to recur.

Researchers from China's Nanjing University developed a new type of nanoparticles that can recognize HER2 protein on breast cancer cells and target them for destruction.

According to their findings published in Angewandte Chemie International Edition, in vitro experiments, the nanoparticles specifically targeted HER2 positive cells and inhibited cell proliferation by 30 percent.

In vivo tests, the tumor volume of mice injected with the nanoparticles was about half the control group.

The researchers said that their study provided insights on developing new treatments for HER2 positive breast cancer and new evidence to studies on nanoparticles for cancer therapies.