in-PharmaTechnologist presents its round-up of the latest drug delivery research developments in the pharmaceutical world, including tumour targeting peptides and lipid nanoparticle drug-delivery technology.
Alnylam has delivered promising Phase I results for an RNAi compound designed to treat amyloidosis, thanks to lipid nanoparticle (LNP) drug-delivery developed by Tekmira.
The LNP platform works by combining siRNAs (small interfering RNAs) with uniform lipid nanoparticles which are effective in delivering RNAi therapeutics to disease sites.
Canadian-based Tekimira’s technology – referred to as stable nucleic acid-lipid particles or SNALP – was used to deliver Alnylam’s RNAi (ribonucleic acid interference) therapeutic targeting transthyretin (TTR).
The drug was well tolerated with no serious adverse events.
The partnership – first established in 2007 – has not been all plain sailing. Earlier this year Tekmira filed suit against Alnylam, claiming patent and license agreement violations over the use of its platform. Media reports say the dispute is further highlighted by the companies’ launching separate press releases on the research.
However in Tekmira's statement, Mark Murray, president and CEO, insisted: “We anticipate additional LNP-enabled clinical data in the coming months, including from Alnylam's ALN-PCS program and Tekmira's TKM-PLK1 program.”
Sanford-Burnham scientists believe they can provide a targeted cancer drug delivery to most tumors using a Trojan-horse-style peptide.
The researchers bound a small protein, called IF7 with a carbohydrate-binding protein found in said vessels, known as annexin 1. Together they are specifically attracted to the blood vessels that feed tumors.
When combined with anti-cancer drug SN-38, the protein shrank tumors in mice substantially compared to other methods of delivery. However the drug caused no visible side effects.
The team’s analysis was based solely on colon cancer, but they now believe the method could be an effective drug delivery vehicle for many common tumors.
Minoru Fukuda, professor in Sanford-Burnham's National Cancer Institute (NCI)-designated Cancer Center and co-author of the study, said: “Although we tested colon tumors in this study, theoretically any tumor that induces expression of annexin 1 in blood vessels would work with this system-it just depends on what kind of drug it's paired with.”
Researchers at the University of Sheffield say they could wipe out invasive magnetic nanoparticle delivery using shape-changing miniature devices that could deliver to tumor sites of their own accord.
Currently nano-particulate drugs can be delivered by encapsulating magnets into the technology, however implanting magnets is an invasive method.
In a bid to create a system which can guide itself through the body’s different environments, the team, led by Sheffield University’s Stephen Ebbens, propose a self-assembling, shape-changing delivery system made from hydrogels.
And according to the research – still at fundamental level – the degree of interaction between the individual long molecules can be controlled using different chemicals.
Ebbens told The Engineer: “The signalling chemical will ideally be a unique marker for the therapeutic delivery site.
“The first approach we are investigating is based on materials that change size in response to the signal.
“This size change could be used to release drug cargo from the surface of the delivery device, for example, by opening up pores or causing the physical detachment of other carriers, such as vesicles.”