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Updated: May 4, 2026
Generation of Alginate Microspheres for Biomedical Applications
Published on: August 12, 2012
Sodium alginate microspheres loaded with Quercetin/Mg nanoparticles as novel drug delivery systems for osteoarthritis
Jun Chen1, Guoya Wu1, Jian Wu1
1Department of Orthopedics, Xianning Central Hospital, The First Affiliated Hospital of Hubei University of Science and Technology, NO. 228 Jingui Road, Xian'an District, Xianning, Hubei, 437100, China.
Background:
Osteoarthritis (OA) is the most prevalent arthritic disease characterized by cartilage degradation and low-grade inflammation, for which there remains a lack of efficacious therapeutic interventions. Notably, mitigating the impact of oxidative stress (OS) and inflammatory factors could help alleviate or hinder the advancement of OA. Given the benefits of both quercetin (Que) and Magnesium ion (Mg2+) in OA treatment, coupled with the structural properties of Que, we have innovatively developed the Que-Mg2+ nanoparticles (NPs), aiming to deliver both Que and Mg2+ simultaneously and achieve enhanced therapeutic outcomes for OA. Moreover, to avoid the adverse reactions linked to frequent injections, sodium alginate (SA) microspheres encapsulating Que-Mg2+ NPs (Que-Mg@SA) were designed to treat the H2O2-induced OA cell model.
Methods:
Que-Mg@SA microspheres were synthesized using the ionotropic gelation technique, with calcium chloride acting as the cross-linking agent. Comprehensive characterization of the Que-Mg@SA was conducted through transmission electron microscope (TEM), dynamic light scattering (DLS), optical microscope, and scanning electron microscope (SEM), which provided detailed insights into their size, zeta potential, morphology, and micromorphology. Additionally, the microsphere swelling rate and Que release were evaluated. The biocompatibility of Que-Mg@SA microspheres, along with their impact on chondrocyte viability, were detected through CCK-8 assay and live/dead cell staining. Furthermore, the antioxidant and anti-inflammatory properties of Que-Mg@SA were evaluated by examining the ROS scavenging ability and pro-inflammatory factors levels, respectively. Finally, the regulatory influence of Que-Mg@SA microspheres on extracellular matrix (ECM) metabolism in OA was assessed by immunofluorescence staining and Western blot.
Results:
Characterization results revealed that Que-Mg NPs exhibit nanoscale diameter, exceptional stability, and good dispersibility, while Que-Mg@SA possesses high entrapment efficiency (EE%) and loading efficiency (LE%), pronounced hygroscopic properties, and sustained drug-release capabilities. Additionally, in vitro cellular assays revealed that the biocompatible Que-Mg@SA microspheres significantly restored chondrocyte viability, scavenged H2O2-induced excessive ROS, reduced the levels of inflammatory cytokines, upregulated cartilage anabolic gene expression, downregulated cartilage catabolic protease gene expression, and maintained the metabolic balance of cartilage tissue.
Conclusion:
The functionalized Que-Mg@SA microspheres developed in our study hold great promise as a drug delivery system for OA and potentially other biomedical applications.
Clinical Trial Number:
Not applicable.
Insights
This study developed quercetin-magnesium (Que-Mg) nanoparticles encapsulated in sodium alginate (SA) microspheres for osteoarthritis treatment. The novel Que-Mg@SA microspheres effectively reduced inflammation and oxidative stress, showing promise for cartilage repair.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Drug Delivery Systems
Background:
- Osteoarthritis (OA) is a prevalent degenerative joint disease characterized by cartilage degradation and inflammation.
- Current therapeutic interventions for OA lack efficacy, highlighting the need for novel treatments.
- Oxidative stress and inflammation significantly contribute to OA progression.
Purpose of the Study:
- To develop and characterize novel quercetin-magnesium (Que-Mg) nanoparticles encapsulated within sodium alginate (SA) microspheres (Que-Mg@SA) for enhanced OA treatment.
- To evaluate the therapeutic potential of Que-Mg@SA in an in vitro model of OA by assessing its antioxidant, anti-inflammatory, and cartilage-protective effects.
Main Methods:
- Que-Mg@SA microspheres were synthesized using ionotropic gelation and characterized using TEM, DLS, SEM, and optical microscopy.
- Microsphere swelling, drug release, biocompatibility (CCK-8 assay, live/dead staining), antioxidant activity (ROS scavenging), anti-inflammatory effects (cytokine levels), and ECM metabolism regulation (Western blot, immunofluorescence) were evaluated.
- An in vitro OA cell model induced by H2O2 was used to assess the efficacy of Que-Mg@SA.
Main Results:
- Que-Mg@SA microspheres demonstrated nanoscale dimensions, high stability, good dispersibility, high entrapment and loading efficiencies, hygroscopic properties, and sustained drug release.
- In vitro assays confirmed the biocompatibility of Que-Mg@SA, its ability to restore chondrocyte viability, scavenge ROS, reduce inflammatory cytokines, and promote cartilage ECM anabolism.
- Que-Mg@SA effectively upregulated anabolic gene expression and downregulated catabolic protease gene expression, maintaining cartilage metabolic balance.
Conclusions:
- The developed functionalized Que-Mg@SA microspheres represent a promising drug delivery system for osteoarthritis.
- This novel system demonstrates significant potential for OA therapy and other biomedical applications.
- Que-Mg@SA offers a viable alternative to frequent injections, potentially improving patient compliance and therapeutic outcomes.
