microsphere

noun

mi·​cro·​sphere ˈmī-krə-ˌsfir 

plural microspheres

: a tiny solid or hollow sphere (as of glass, ceramic, or polymer) that is 1 to 1000 micrometers in diameter and that is used in industrial and consumer products and in biomedical applications (such as drug delivery or diagnostic imaging)

The idea is to package protein drugs into microspheres. From a single injection under the skin the drug is released at a slow and steady rate over a long period.

—Michael Gianturco

With microspheres, boat bumpers are more buoyant and cosmetics silky smooth. Drugs become more effective and paints more stain resistant. Microspheres are even responsible for the smell of scratch-and-sniff stickers.

—Rachel Ross

A microsphere is not the same as a microparticle, because microparticle is a general term that refers only to the size of the granular material and does not provide information on the shape. Microspheres are always round and spherical.

—Cynthia A. Gosselin

… a gas-filled synthetic polymer microsphere that enhances the detection of blood flow within the heart muscle in echocardiograms …

—Kelly Holman

microspherical

ˌmī-krə-ˈsfir-i-kəl 

-ˈsfer-

adjective

Examples of microsphere in a Sentence

Recent Examples on the Web

Infused with apricot microspheres, the cleanser should be used no more than three times a week and followed up with a calming elixir fortified with soothing ingredients such as ceramide and chamomile. —Lauren Valenti, Vogue, 4 Oct. 2024

That’s because the ingredients list includes oil-absorbing microspheres that actually absorb surface oils in effort to reduce any excess shine. —Glamour, 29 Mar. 2024

The products contain hyaluronic acid microspheres to help smooth fine lines and wrinkles, along with a peptide complex to enhance youthful skin, fatty acids to help protect and restore, and collagen stabilizer to help moisturize and provide a smoothing effect. —Dahvi Shira, Forbes, 28 Mar. 2024

The retinol is encapsulated in botanical microspheres for gradual release, mitigating redness and irritation while also infusing skin with the calming antioxidant properties of edelweiss. —Mary Honkus, Glamour, 27 Feb. 2024

Word History

First Known Use

1950, in the meaning defined above

Medical Definition

microsphere

noun

mi·​cro·​sphere -ˌsfir 

: a spherical shell that is usually made of a biodegradable or resorbable plastic polymer, that has a very small diameter usually in the micron or nanometer range, and that is often filled with a substance (as a drug or antibody) for release as the shell is degraded