Fabrication of new elastic 'soft capsule' using nano-sized flakes

May 30, 2012
Fig. Formation of the flake shell. The flake shell is formed by dissolving silica nanoparticles from the outside and precipitation/aggregation of nanosheets in the surrounding area.

A research group headed by MANA Scientist Dr. Qingmin Ji of the National Institute for Materials Science (Japan), in joint study with Prof. Frank Caruso of the University of Melbourne, developed a new elastic capsule using an inorganic nanometer-thickness flake-shaped material (nanosheets). Tests of the new capsule demonstrated that the release duration of anticancer drugs and other drugs can be controlled freely and can also be extended by several times by using the newly-developed capsule.

Drug delivery systems (DDS) are considered an extremely promising technique for transporting drugs effectively and reliably to the site of pathologies such as cancers. As drugs are absorbed and decomposed in human bodies, they disperse widely, including areas other than the affected part, and it is not necessarily possible to control them to reach the intended part. For this reason, the development of micro-capsules and nano-capsules for controlled drug delivery is an urgent matter.

Until now, such as silica and organic materials such as fats and polymers have been used to form capsules. Inorganic capsules are hard, strong, and tough, but their structures are not easily adjusted to adapt to conditions. On the other hand, organic capsules are flexible and structural adjustment is possible, but they have the drawback of low . Thus, the development of a drug-carrier capsule structure with the advantages of both types had been desired.

In this research, a “soft” capsule was developed by creating a fluffy assembly of nanosheets of silica, which is an inorganic material. While this capsule consists of a mechanically-stable inorganic material, free control of its structure is also possible.

This capsule expands and contracts when heated and cooled, and the size of the pores in the outer wall, which are formed by the spaces between the nanosheets and serve as passages for drug release, can be controlled over a wide range by adjusting pH to various levels. As a result, the sustained release time of the anticancer drug DOX was successfully extended by several times in comparison with conventional porous capsules having a simple structure. It was also possible to control the drug release duration and drug storage amount by changing the pore structure of the capsule, thereby changing the drug release routes, by advance treatment of the capsule under appropriate pH conditions.

These research results are to be announced in the online edition of the scientific journal Small.

Explore further: Wrinkled membranes create novel drug-delivery system

Related Stories

Nanoparticles create biocompatible capsules

March 6, 2006

An innovative strategy of mixing lipids and nanoparticles to produce new drug and agricultural materials and delivery vehicles has been developed by researchers at the University of Illinois at Urbana-Champaign.

Recommended for you

A new way to make higher quality bilayer graphene

February 8, 2016

(Phys.org)—A team of researchers with members from institutions in the U.S., Korea and China has developed a new way to make bilayer graphene that is higher in quality than that produced through any other known process. ...

Graphene is strong, but is it tough?

February 4, 2016

Graphene, a material consisting of a single layer of carbon atoms, has been touted as the strongest material known to exist, 200 times stronger than steel, lighter than paper, and with extraordinary mechanical and electrical ...

Nanoparticle ink could combat counterfeiting

February 5, 2016

(Phys.org)—Researchers have demonstrated that transparent ink containing gold, silver, and magnetic nanoparticles can be easily screen-printed onto various types of paper, with the nanoparticles being so small that they ...

Tiniest spin devices becoming more stable

February 3, 2016

(Phys.org)—In 2011, the research group of Roland Wiesendanger, Physics Professor at the University of Hamburg in Germany, fabricated a spin-based logic device using the spins of single atoms, a feat that represents the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.