Preparation and evaluation of a novel bioactive glass/lysozyme/PLGA composite microsphere

Abstract

Objective: The objective of this study was to fabricate a novel nano-bioceramics incorporated lysozyme poly (d, l-lactide-co-glycolide) (PLGA) microsphere.

Methods: The nano-bioceramics was used as a biodegradable and sustained-release antacid to stabilize the lysozyme in the drug release process. First, the nano-bioceramics were prepared by sol-gel method, and then were characterized by energy dispersive X-ray analysis, dynamic light scattering and in vitro degradation test. Second, the lysozyme PLGA microsphere incorporated with nano-bioceramic was fabricated by the S/W/O/W emulsion solvent evaporation method. The microsphere was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV circular dichroism (UV CD). Finally the in vitro drug release and bioactivity test was carried out.

Results: The composition of the nano-bioceramics was 58% SiO₂, 36% CaO, 6% P₂O₅, and the average particle size was 295 nm. The nano-bioceramics incorporated lysozyme PLGA microspheres were prepared by the multi-emulsion method. The SEM results showed that the bioceramics was uniformly distributed in the PLGA microsphere. Results from in vitro lysozyme release test exhibited a prolonged release time for 1month. The FTIR and UVCD results suggested that the lysozyme in the drug release process had a similar secondary structure conformation to the native one. The Micrococcus lysodeikticus test showed that the microspheres incorporated with bioceramics provided long-term protein stability against the acidic environment resulted from PLGA’s degradates and more than 90% of the lysozyme released over the 1 month period was preserved in a bioactive form.

Conclusion: A novel bioceramics incorporated lysozyme PLGA microsphere was prepared with potentials for sustained protein release formulation.

• Bioactive
• bioactivity glass
• lysozyme
• PLGA
• protein

Declaration of interest

This manuscript has been sponsored by the Jiangsu university project (Project number 11JDG023); The Jiangsu province college and university natural science research project (Project number 11KJB350001); Natural science foundation of Jiangsu province, genereal program, (Project number BK2011496); China Postdoctoral Science Foundation (Project number 2012M521022). The authors report no conflicts of interest.