Delivering Bioactive Components for Medical Treatments

SLU ID 14-013 | Fabricating Hydrolytically Degradable Polyethylene Glycol Microsphere Delivery Vehicles

Intellectual Property Status


  • Patented
  • Know-how based
  • Licensee
  • Development partner
  • Commercial partner


Hydrogel microspheres of less than 200 μm are powerful tools that have a multitude of applications in the areas of drug delivery, tissue engineering, and biosensors. Hydrogels are a preferred choice because of their tissue-like properties; high water content; ease of fabrication; and tunable chemical, mechanical and biological characteristics. Numerous methods have been proposed to generate hydrogel microspheres. However, these methods are often harmful for biological applications such as cell or protein encapsulation. Moreover, most of the dispersion-based methods involve the use of either organic solvent or surfactants. Although methods such as microfluidic devices offer a lot of control over process parameters and fabrication characteristics, the devices are very complex in design and thus have limited applications.


Researchers at Saint Louis University have developed a method to fabricate hydrogel microspheres composed of multiarm polyethylene glycol acrylates (PEG-Ac) or vinyl sulfones (PEG-VS) and dithiol crosslinkers. The microspheres are biocompatible and suitable for encapsulation and delivery of bioactive components like proteins, cells, or drugs.


The potential benefits of this technology include:

  • Increase ability to tune degradation rates
  • Increase ability to specify mesh size
  • Increase ability to tune protein release kinetics
  • Increase ability to control microsphere size
  • Increase encapsulation efficiency
  • Increase the amount of time that biological activity maintained
  • Minimize damage to bioactive component deliverables
  • Minimize invasiveness of treatments for knee osteoarthritis
  • Minimize the invasiveness of enzyme replacement therapies
  • Minimize the invasiveness of dermal repair procedures


This technology has several potential applications including:

  • Delivering proteins
  • Delivering cells
  • Delivering enzymes
  • Delivering drugs


Saint Louis University is seeking partners to further develop and commercialize this technology.


  • U.S. patent 9,968,558