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Porous PLGA microspheres loaded with PTH1-34 peptide for long-term treatment of OA
Wang Diaodiao1,2,3, Tang Miaotian4, Ren Pengcheng1,2,3
1Department of Joint Surgery, Peking University Ninth School of Clinical Medicine, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China.
Background:
Osteoarthritis (OA) is a chronic disease characterized by degeneration of articular cartilage, affecting over 530 million patients worldwide. Current oral medications such as non-steroidal anti-inflammatory drugs (NSAIDs) can only alleviate symptoms and are associated with numerous adverse effects. Although teriparatide (PTH1-34) exhibits dual functions of chondroprotection and osteogenic effects, its clinical application is significantly limited by its short biological half-life (30-60 min) and accelerated degradation within the inflammatory microenvironment of joint cavities.
Methods:
Porous sustained-release microspheres (M@PTH1-34) were fabricated using FDA-approved poly (lactic-co-glycolic acid) (PLGA) as the matrix, encapsulating PTH1-34 within their multi-channel porous structure. Uniform microsphere preparation and high-efficiency drug loading were achieved through membrane emulsification and temperature-controlled embedding techniques. To systematically evaluate the sustained-release profile and therapeutic outcomes, both in vitro and in vivo OA models were established, enabling comprehensive analysis of cartilage repair efficacy, anti-inflammatory regulation, and immunomodulatory effects.
Results:
PTH1-34 could be efficiently loaded into microspheres after self-healing and achieve consistent release over 30 days with biological activity being maintained. In OA model rats, M@PTH1-34 significantly improved behavioral and radiological outcomes, increased cartilage smoothness and thickness, and increased the expression of chondrogenic markers. Additionally, in vitro and in vivo safety tests revealed no significant safety issues. These findings indicate that M@PTH1-34 holds promise as a long-lasting, cost-effective, and safe therapeutic approach for OA.
Conclusion:
This study successfully developed a uniform-sized PLGA-based sustained-release microsphere system (M@PTH1-34) that enables continuous drug release for over 30 days following single intra-articular administration. M@PTH1-34 exerts its therapeutic effects on osteoarthritis through the following two ways: (1) Promoting cartilage repair by enhancing the chondrogenic differentiation ability of bone marrow mesenchymal stem cells (BMSCs); (2) Improve the inflammatory microenvironment of joints by inhibiting the expression of inflammatory factors (such as IL-1β) and regulating the polarization state of M1/M2 macrophages.
The Translation Potential Of This Article:
The system demonstrates prominent clinical translation advantages: (1) Innovative utilization of FDA-approved PLGA carrier combined with membrane emulsification technique ensures precise size control and standardized production; (2) Localized delivery strategy achieves targeted retention within articular cavity, validated by animal studies showing no systemic exposure risks; (3) Standardized preparation process demonstrates the feasibility of industrial-scale production.
Insights
This study developed microspheres (M@PTH1-34) for sustained drug release, effectively treating osteoarthritis by promoting cartilage repair and reducing inflammation. The M@PTH1-34 system offers a promising, long-lasting, and safe therapeutic option for osteoarthritis patients.
Area of Science:
- Biomaterials Science
- Drug Delivery Systems
- Regenerative Medicine
Background:
- Osteoarthritis (OA) affects over 530 million people globally, with current treatments offering limited efficacy and significant side effects.
- Teriparatide (PTH1-34) shows chondroprotective and osteogenic potential but is limited by its short half-life and degradation in inflammatory joint environments.
Purpose of the Study:
- To develop a sustained-release system for PTH1-34 to overcome its pharmacokinetic limitations for osteoarthritis treatment.
- To evaluate the efficacy, safety, and immunomodulatory effects of the novel microsphere-based drug delivery system (M@PTH1-34) in preclinical osteoarthritis models.
Main Methods:
- Fabrication of porous sustained-release microspheres (M@PTH1-34) using FDA-approved poly (lactic-co-glycolic acid) (PLGA) and PTH1-34 via membrane emulsification.
- Establishment of in vitro and in vivo osteoarthritis models to assess sustained release, cartilage repair, anti-inflammatory, and immunomodulatory effects.
- In vitro and in vivo safety assessments were conducted.
Main Results:
- M@PTH1-34 achieved consistent PTH1-34 release over 30 days, maintaining biological activity.
- In vivo studies in OA model rats demonstrated significant improvements in behavioral and radiological outcomes, enhanced cartilage repair, and increased chondrogenic marker expression.
- In vitro and in vivo safety tests showed no significant adverse effects.
Conclusions:
- A uniform-sized PLGA-based sustained-release microsphere system (M@PTH1-34) was successfully developed for over 30 days of continuous drug release after a single intra-articular injection.
- M@PTH1-34 promotes cartilage repair by enhancing bone marrow mesenchymal stem cell (BMSC) chondrogenic differentiation and improves the joint inflammatory microenvironment by inhibiting inflammatory factors and modulating macrophage polarization.
- The M@PTH1-34 system demonstrates significant clinical translation potential due to its precise size control, standardized production, localized delivery, and lack of systemic exposure risks.
