Microencapsulation of protein into biodegradable matrix: a smart solution cross-linking technique.

Area of Science:

• Biomaterials Science
• Pharmaceutical Technology
• Drug Delivery Systems

Background:

• Sustained-release albumin microspheres (MSs) are produced via albumin cross-linking.
• A key challenge is preventing active pharmaceutical ingredient (API) cross-linking with the MS matrix during formulation.
• This can compromise API integrity and therapeutic efficacy.

Purpose of the Study:

• To develop and validate a novel "solution cross-linking-microencapsulation" method.
• To prevent API cross-linking with albumin MSs.
• To ensure the structural integrity and bioactivity of encapsulated APIs.

Main Methods:

• Albumin solution was cross-linked with glutaraldehyde.
• Excess glutaraldehyde was neutralized with sodium bisulphite.
• Active pharmaceutical ingredient (API) was added, followed by spray drying to form microspheres.
• Lysozyme was used as a model API for formulations FL1 and FL2.

Main Results:

• Physicochemical characterization (FT-IR) and bioactivity assays confirmed preserved native structure and bioactivity of the encapsulated API.
• In vivo studies indicated no significant increase in antigen-specific serum-IgG levels.
• This suggests the cross-linked albumin matrix is safe and biocompatible.

Conclusions:

• The developed "solution cross-linking-microencapsulation" method effectively prevents API cross-linking during albumin MS formulation.
• The method ensures the structural integrity and bioactivity of encapsulated APIs.
• The cross-linked albumin matrix demonstrates favorable safety and biocompatibility for drug delivery applications.