PLGA Microspheres Containing Hydrophobically Modified Magnesium Hydroxide Particles for Acid Neutralization-Mediated Anti-Inflammation

• Published in: Tissue engineering and regenerative medicine Vol. 18; no. 4; p. 613
• Main Authors: Kim, Joon-Kyu, Go, Eun-Jin, Ko, Kyoung-Won, Oh, Hyeon-Ji, Han, Jieun, Han, Dong Keun, Park, Wooram
• Format: Journal Article
• Language: English
• Published: Korea (South) 01-08-2021
• Subjects: Animals; Anti-Inflammatory Agents; Lactic Acid; Magnesium Hydroxide; Mice; Microspheres; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Magnesium hydroxide; Polymeric microspheres; Acid neutralization; Anti-inflammation; Biodegradable polymers; Poly(lactic-co-glycolic acid)
• ISSN: 2212-5469
• DOI: 10.1007/s13770-021-00338-z

Poly(lactic-co-glycolic acid) (PLGA) microspheres have been actively used in various pharmaceutical formulations because they can sustain active pharmaceutical ingredient release and are easy to administer into the body using a syringe. However, the acidic byproducts produced by the decomposition of PLGA cause inflammatory reactions in surrounding tissues, limiting biocompatibility. Magnesium hydroxide (MH), an alkaline ceramic, has attracted attention as a potential additive because it has an acid-neutralizing effect.
To improve the encapsulation efficiency of hydrophilic MH, the MH particles were capped with hydrophobic ricinoleic acid (RA-MH). PLGA microspheres encapsulated with RA-MH particles were manufactured by the O/W method. To assess the in vitro cytotoxicity of the degradation products of PLGA, MH/PLGA, and RA-MH/PLGA microspheres, CCK-8 and Live/Dead assays were performed with NIH-3T3 cells treated with different concentrations of their degradation products. In vitro anti-inflammatory effect of RA-MH/PLGA microspheres was evaluated with quantitative measurement of pro-inflammatory cytokines.
The synthesized RA-MH was encapsulated in PLGA microspheres and displayed more than four times higher loading content than pristine MH. The PLGA microspheres encapsulated with RA-MH had an acid-neutralizing effect better than that of the control group. In an in vitro cell experiment, the degradation products obtained from RA-MH/PLGA microspheres exhibited higher biocompatibility than the degradation products obtained from PLGA microspheres. Additionally, the RA-MH/PLGA microsphere group showed an excellent anti-inflammatory effect.
Our results proved that RA-MH-encapsulated PLGA microspheres showed excellent biocompatibility with an anti-inflammatory effect. This technology can be applied to drug delivery and tissue engineering to treat various incurable diseases in the future.