Novel Drug or DNA Delivery System Using Laser Activated Gold Pyramids

Highlights

• A novel method of introducing substances into cells without damaging the cell membrane has been discovered
• The method creates temporary pores with laser-activated gold pyramids
• It could be useful in the fields of gene therapy and intracellular drug delivery

A research team is exploring the use of laser-activated gold pyramids to introduce drugs or DNA into cells through temporary pores without affecting the cells. Their study was published in ACS Nano. There are various forms of delivering drugs into the body, like oral pills, intravenous injections and patches applied on the skin. These affect the entire body, and are therefore associated with side effects. Efforts are being made to deliver drugs in such a way, so as to bring about a more localized effect. For example, administering anti-asthma drugs via inhalation brings about a direct effect on the respiratory tract with minimal side effects to other parts of the body.

Localized delivery of drugs is particularly important in cancer therapy. Chemotherapy drugs are highly toxic to the cancer as well as the normal cells, thus causing severe side effects. Targeted therapy is now being used in several cancers, which attack only the cancer cells without affecting normal cells.

Gene therapy has been used in the treatment of cancers and genetic disorders. Genes have to be introduced into the cells to bring about changes in the genetic material of the affected cells. Researchers have come up with a new technique that could be used to bring about this introduction.

The research team fabricated surfaces, each the size of a quarter and containing a 10 million gold pyramids. They used a method called template stripping to make the surfaces in a cost-effective manner. HeLa cells were cultured on top of the pyramids, which were surrounded by a solution that contain molecules that needed to enter the cells.

Using laser, the tips of the pyramids were heated to a temperature of 300 degrees Celsius. This created bubbles that made small pores in the cell membrane surrounding the cells and allowed the passage of the surrounding molecules into the cells. The pores then closed by themselves, if they were made quickly.

The research team found that:

• The procedure allowed the entry of molecules with high efficiency into the cells
• The pores allowed the entry of small as well as large, and diverse substances into the cells
• The pores formed are temporary and heal without damaging the cells
• The technique can be used to deliver cargo to millions of cells at a time. This, and switching to nanosecond laser adds to the cost-effectiveness of the procedure.

The researchers suggest that their discovery could be useful in situations where therapies like drugs or DNA can be introduced into cells in the laboratory and then introduced into the body.

Advertisement

The research will hopefully provide a new option of drug delivery, which will be efficient, cost effective, and able to deliver a wide variety of molecules of different sizes.

Reference

1. Saklayen N et al. Intracellular Delivery Using Nanosecond-Laser Excitation of Large-Area Plasmonic Substrates. ACS Nano. DOI: 10.1021/acsnano.6b08162 Publication Date (Web): March 14, 2017

Source-Medindia