Development and characterization of antacid microcapsules to buffer the acidic intervertebral disc microenvironment

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Biochemistry

Background:

• Intervertebral disc (IVD) degeneration is characterized by an acidic microenvironment, impacting cell function and matrix turnover.
• Current cell-based therapies for IVD regeneration face challenges due to these hostile microenvironmental conditions.

Purpose of the Study:

• To develop and characterize antacid microcapsules for neutralizing acidic conditions in degenerated IVDs.
• To evaluate the therapeutic potential of combining antacid microcapsules with cellular microcapsules in a hybrid gel system for IVD regeneration.

Main Methods:

• Screening of five pH-neutralizing agents, with Mg(OH)2 and CaCO3 selected for further study.
• Fabrication and characterization of antacid-alginate microcapsules using electrohydrodynamic spraying.
• Assessment of microcapsule performance in a bovine disc explant model under degenerative conditions.

Main Results:

• Calcium carbonate (CaCO3) demonstrated superior pH neutralization capacity, release kinetics, and cellular compatibility compared to other agents.
• CaCO3 microcapsules successfully elevated the pH in the acidic core of the hybrid cellular gel system within the disc explant model.
• The neutralizing effect of CaCO3 microcapsules is estimated to persist for several weeks.

Conclusions:

• Antacid microcapsules, especially CaCO3, can effectively mitigate the acidic microenvironment associated with degenerative disc disease.
• This technology holds significant potential for augmenting cell-based regenerative strategies for IVDs.
• The developed antacid microcapsules offer a promising therapeutic approach to improve conditions for IVD regeneration.