Nanoparticle protects protein drug cargo


The nanoparticles can carry their own weight in proteins © Wiley-VCH

An international team of researchers at Brigham and Women’s Hospital, Boston, US has developed novel nanoparticles that could deliver protein drugs to where they are needed unscathed. Protein drugs that use nanoparticles as a delivery vehicle can often be damaged in transit, but the nanoparticles developed by the Boston lab don’t suffer from this drawback.

Interactions between conventional drug delivery systems, such as hydrogel nanaoparticles, and leftover solvents from the fabrication process can damage protein drugs. To create a successful drug delivery vehicle that can deliver a drug protein unharmed, they need to be biocompatible, biodegradable and eco-friendly. The Boston scientists have achieved all of the above by relying on one property of poly-electrolytes: static electricity.

The scientists mixed poly(lactide-co-glycolic acid) (PLGA) and L-arginine-based polycations (PC) to produce a hydrophilic co-polymer, which then assemble into PLGA–PC nanoparticles, ‘just like fluff attaching to clothes or gloves in winter’, author Jun Wu at Brigham Hospital explains. The small size of the nanoparticle (20–80nm) and the poly-cationic moieties drives proteins, including insulin and TNF-alpha, to cling tightly to the nanoparticle core in just water, without any organic solvent present.

Strong electrostatic attractions also help substantial amounts of the protein to cling to the nanoparticles – up to 20% more than the weight of the nanoparticles themselves. The scientists also found that adding lipid-PEG to the protein–nanoparticle complex helps to protect the proteins.

‘This protein–nanoparticle complex could be looked at as a spherical chocolate with some nuts inside,’ says Wu. The proteins constitute the chocolate, and the nanoparticles the nuts.

Wu hopes that ‘this platform could be used as a protein bomb to destroy the cancers or any other diseased parts in the human body’. As they have used US Food and Drug Administration approved biocompatible raw materials such as amino acids, fatty diacids and diols to develop the nanoparticles, getting approval for clinical trials should be easier too.

Wu says that their end goal is to create nanocarriers loaded with nucleic acids or other drugs besides proteins, avoiding the use of organic solvents. He hopes that this ‘green approach’ could help ‘patients make nanocarriers by themselves by simply mixing the formulations following a very simple protocol’.

However there are still challenges. ‘The system needs to be further optimised before going to animal studies [or] clinical trials’, says Wu. He adds that the group has plans to conduct multiple animal studies for diabetes, cancers and cardiovascular diseases.

Sangyong Jon at the Korea Advanced Institute of Science and Technology, South Korea says that loading the carriers with such a large amount of protein is exceptional. However, he warns that the PLGA copolymer might have some toxicity problems and this should be investigated.

‘We are aiming to have some optimised systems for clinical trial within three to five years if the animal study results are promising,’ says Wu.

Related Content

Hairy proteins survive stomach trip

9 June 2013 Research

news image

Polymer modification protects enzymes from digestive track opening up oral route for biological drugs

Caged toxin for safer, better bacterial vaccines

3 December 2013 Research

news image

Hybrid nanoparticles can deliver unmodified toxins giving the immune system a better education to resist future infections

Most Read

UC Davis chemist sentenced to four years over explosion

19 November 2014 News and Analysis

news image

Postdoc sentenced over attempt to make explosive device and reckless disposal of hazardous waste

Spanish fly

10 October 2013 Podcast | Compounds

news image

Helen Scales looks at cantharidin, the active ingredient in this famous aphrodisiac

Most Commented

Beetle behind breath test for bank notes

17 November 2014 Research

news image

Photonic crystal inks inspired by longhorn beetle could help to fight counterfeiting

Bayer wins race to buy Merck & Co consumer care

9 May 2014 Business

news image

$14bn deal will make Aspirin inventor the number two over-the-counter healthcare company