Dual-crosslinked homogeneous alginate microspheres for mesenchymal stem cell encapsulation

J Mater Sci Mater Med. 2018 Aug 27;29(9):143. doi: 10.1007/s10856-018-6151-4.

Abstract

A smart hydrogel material was used in combination with custom microfluidic devices (MFDs) to create microspheres for human mesenchymal stem cell (MSC) encapsulation. Methods for fabricating homogeneous stimuli-responsive microspheres for MSC encapsulation and cell delivery have gained interest to increase viability and manipulate microencapsulation within microspheres 10-1000 µm in diameter. Herein, MFDs were combined with non-toxic smart hydrogel materials to tune both the size and mechanics of the microspheres. Traditional hydrogels have a single input/stimulus for crosslinking, utilize potentially toxic ultraviolet radiation, and fail to mimic surrounding musculoskeletal tissue mechanics. Thus, it is highly beneficial to encapsulate MSCs inside a mechanically-stable microsphere made from naturally-derived materials. The objectives of this research were to optimize microsphere fabrication techniques using custom microfluidic devices (MFDs), and to encapsulate viable MSCs within visible-light crosslinked smart-alginate microspheres, with tunable mechanical properties. Microsphere production was characterized optically, and MSC viability, post-encapsulation, was verified using a standard florescence assay. Cell viability was maintained in chemically-modified alginate homogenous microspheres post encapsulation, and after subsequent crosslinking via green light exposure.

MeSH terms

  • Alginates / chemistry*
  • Cell Culture Techniques
  • Cell Survival
  • Cells, Cultured
  • Cross-Linking Reagents / chemistry
  • Humans
  • Hydrogels / chemistry
  • Kinetics
  • Lab-On-A-Chip Devices
  • Light
  • Mesenchymal Stem Cells / cytology*
  • Microfluidics
  • Microscopy, Fluorescence
  • Microspheres*
  • Photochemistry
  • Polymers / chemistry
  • Rheology
  • Stress, Mechanical
  • Tissue Engineering / methods*
  • Ultraviolet Rays
  • Viscosity

Substances

  • Alginates
  • Cross-Linking Reagents
  • Hydrogels
  • Polymers