Characterization, Bioactivity, and Biodistribution of 35 kDa Hyaluronan Fragment

Area of Science:

• Biochemistry
• Immunology
• Pharmacology

Background:

• Hyaluronic acid (HA) is known for tissue protection, but the specific biological properties of low molecular weight HA (HA35) require further characterization.
• Understanding HA35's cellular effects and biodistribution is crucial for exploring its therapeutic applications.

Purpose of the Study:

• To evaluate and compare the cellular effects and in vivo biodistribution of HA35 against high molecular weight HA (HA1600).
• To assess the impact of HA35 and HA1600 on immune cell migration, nitric oxide (NO) and reactive oxygen species (ROS) generation, and gene expression.

Main Methods:

• In vitro assessment of HA35 and HA1600 effects on cultured macrophages, microglia, and lymphocytes.
• Measurement of cell migration, NO and ROS generation, and gene expression profiles.
• In vivo biodistribution studies of radiolabeled HA35 (^99mTc and ¹²⁵I) in C57BL/6J mice following intradermal or intravenous administration.

Main Results:

• Both HA35 and HA1600 enhanced immune cell migration and reduced NO and ROS generation via HA receptor binding.
• HA35 demonstrated a more pronounced upregulation of gene expression in macrophages and microglia compared to HA1600.
• Radiolabeled HA35 rapidly accumulated in the liver, spleen, and lymph nodes after administration.

Conclusions:

• HA35 exhibits cellular bioactivity comparable to HA1600, with a broader impact on immune cell gene expression.
• HA35 shows potential for therapeutic use in managing inflammation-mediated tissue injury.