Bioresorbable hydrogel microspheres for transcatheter embolization: preparation and in vitro evaluation

J Vasc Interv Radiol. 2011 Oct;22(10):1464-1470.e2. doi: 10.1016/j.jvir.2011.06.010. Epub 2011 Aug 4.

Abstract

Purpose: To develop and evaluate a bioresorbable spherical material for embolization.

Materials and methods: New bioresorbable hydrogel microspheres were prepared from carboxymethyl cellulose and chitosan by using an inverse emulsion method. Size distribution of the microspheres was determined with a microscope, and the colorability was tested with Evans blue dye. The compressibility was examined with a texture analyzer. After sieving, the suspendability of the microspheres was tested in saline solution/contrast agent mixture in different ratios, and then the injectability was tested with microcatheters (lumen sizes of 0.0165, 0.019, and 0.027 inches). The in vitro degradability tests were performed in a lysozyme solution. Cell culture study of the microspheres was performed with human fibroblasts.

Results: The microspheres exhibit diameters of 100-1,550 μm with a transparent appearance. Their fracture force can reach 0.58-0.88 N, and fracture deformation varies from approximately 70% to 95% of their original size. These microspheres can be colored by Evans blue dye, and uniform subgroups of microspheres can be readily obtained by sieving. Within 3 minutes, the microspheres form a stable suspension in a 4:6 contrast agent/saline solution mixture, which can be easily injected through microcatheters without aggregating or clogging. These microspheres are biodegradable, with degradation times varying from 2 weeks to 1 month, depending on their composition. Cell culture studies reveal no adverse effect on the growth of human fibroblasts in the presence of the microspheres.

Conclusions: A biodegradable and noncytotoxic microsphere was successfully prepared. It can be well suspended in the contrast solution and easily injected through a microcatheter.

Publication types

  • Evaluation Study

MeSH terms

  • Biocompatible Materials*
  • Carboxymethylcellulose Sodium / chemistry*
  • Carboxymethylcellulose Sodium / toxicity
  • Cells, Cultured
  • Chitosan / analogs & derivatives*
  • Chitosan / chemistry
  • Chitosan / toxicity
  • Coloring Agents / chemistry
  • Compressive Strength
  • Embolization, Therapeutic / methods*
  • Evans Blue / chemistry
  • Fibroblasts / drug effects
  • Humans
  • Hydrogels
  • Materials Testing
  • Microspheres
  • Muramidase / chemistry
  • Oxidation-Reduction
  • Particle Size
  • Time Factors

Substances

  • Biocompatible Materials
  • Coloring Agents
  • Hydrogels
  • carboxymethyl-chitosan
  • Evans Blue
  • Chitosan
  • Muramidase
  • Carboxymethylcellulose Sodium