[Preparation and properties of Talpha1 loaded injectable sustained release microspheres]

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Immunology

Background:

• Thymosin alpha-1 (Talpha) is a peptide with immunomodulatory properties.
• Developing sustained-release formulations for Talpha can improve therapeutic efficacy and patient compliance.
• Biodegradable polymers like PLGA offer a promising platform for injectable drug delivery systems.

Purpose of the Study:

• To prepare and characterize Talpha-loaded PLGA microspheres for injectable sustained release.
• To evaluate the in vitro release behavior and bioactivity of encapsulated Talpha.
• To assess the in vivo pharmacodynamics of Talpha-loaded microspheres in an animal model.

Main Methods:

• Talpha-loaded PLGA microspheres were prepared using the double emulsion (W/O/W) method.
• Microsphere properties (mean diameter, morphology, drug loading) were evaluated.
• In vitro release kinetics (HPLC), bioactivity (CCK-8 assay), and in vivo pharmacodynamics (CD4+/CD8+ ratio via flow cytometry) were assessed.

Main Results:

• Optimized microspheres exhibited good shape, dispersibility, and high drug entrapment efficiency (up to 90.2%).
• A cumulative drug release of up to 90% was observed over one month, indicating sustained release.
• Talpha bioactivity was largely conserved, and the microspheres significantly enhanced immunity in immunosuppressed rats.

Conclusions:

• Injectable Talpha-loaded PLGA microspheres provide a viable one-month sustained release formulation.
• This delivery system effectively preserves Talpha bioactivity and demonstrates significant immunomodulatory effects in vivo.
• The developed microspheres hold promise for future therapeutic applications in immunotherapy.