Alginate-hydroxypropylcellulose hydrogel microbeads for alkaline phosphatase encapsulation

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Protein Therapeutics

Background:

• Proteins are valuable therapeutic agents but face challenges with stability and bioavailability.
• Developing effective delivery systems is crucial for successful protein-based therapies.

Purpose of the Study:

• To engineer novel hydrogel microparticles for improved protein delivery.
• To encapsulate alkaline phosphatase (ALP) within alginate/hydroxypropylcellulose (ALG-HPC) microparticles.
• To characterize the release kinetics and bioactivity of encapsulated ALP.

Main Methods:

• Protein encapsulation within physically cross-linked sodium alginate/hydroxypropylcellulose (ALG-HPC) hydrogel microparticles.
• Characterization of microparticle morphology and size using optical microscopy and SEM.
• Assessment of ALP release profiles under physiological conditions (pH 7.4, 37°C) for chitosan-coated microspheres.
• Evaluation of released ALP activity through induced mineralization assays.
• Analysis of mineral formation using SEM, AFM, FTIR, and XRD.

Main Results:

• Spherical ALG-HPC microparticles (∼4 µm) were successfully fabricated.
• Controlled release of active ALP was achieved with chitosan-coated microspheres, exhibiting no initial burst effect.
• Induced mineralization confirmed the bioactivity of released ALP.
• FTIR and XRD analyses confirmed the formation of hydroxyapatite mineral.

Conclusions:

• ALG-HPC hydrogel microparticles represent a promising platform for the sustained and active delivery of protein therapeutics.
• The developed system overcomes limitations of protein stability and bioavailability.
• The ability to induce mineralization highlights the therapeutic potential of this delivery system.