Biodegradable block copolymers as injectable drug-delivery systems

Byeongmoon Jeong, You Han Bae, Doo Sung Lee and Sung Wan Kim
Additional contact information
Byeongmoon Jeong: Biomedical Polymers Research Building, Room 205, CCCD/Pharmaceutics, University of Utah
You Han Bae: Biomedical Polymers Research Building, Room 205, CCCD/Pharmaceutics, University of Utah
Doo Sung Lee: Biomedical Polymers Research Building, Room 205, CCCD/Pharmaceutics, University of Utah
Sung Wan Kim: Biomedical Polymers Research Building, Room 205, CCCD/Pharmaceutics, University of Utah

Nature, 1997, vol. 388, issue 6645, 860-862

Abstract: Abstract Polymers that display a physicochemical response to stimuli are widely explored as potential drug-delivery systems1,2,3,4. Stimuli studied to date include chemical substances and changes in temperature, pH and electric field. Homopolymers or copolymers of N-isopropylacrylamide5,6 and poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (known as poloxamers)7 are typical examples of thermosensitive polymers, but their use in drug delivery is problematic because they are toxic and non-biodegradable. Biodegradable polymers used for drug delivery to date have mostly been in the form of injectable microspheres or implant systems, which require complicated fabrication processes using organic solvents8. Such systems have the disadvantage that the use of organic solvents can cause denaturation when protein drugs are to be encapsulated. Furthermore, the solid form requires surgical insertion, which often results in tissue irritation and damage. Here we report the synthesis of a thermosensitive, biodegradable hydrogel consisting of blocks of poly(ethylene oxide) and poly(L-lactic acid). Aqueous solutions of these copolymers exhibit temperature-dependent reversible gel–sol transitions. The hydrogel can be loaded with bioactive molecules in an aqueous phase at an elevated temperature (around 45 °C), where they form a sol. In this form, the polymer is injectable. On subcutaneous injection and subsequent rapid cooling to body temperature, the loaded copolymer forms a gel that can act as a sustained-release matrix for drugs.

Date: 1997
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/42218 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:388:y:1997:i:6645:d:10.1038_42218

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/42218

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().