Targeting Human Osteoarthritic Chondrocytes with Ligand Directed Bacteriophage-Based Particles
Aitthiphon Chongchai1,2, Sajee Waramit2, Tunchanok Wongwichai1
1Thailand Excellence Centre for Tissue Engineering and Stem Cells, Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Abstract:
Osteoarthritis (OA) is a degenerative joint disease characterized by progressive deterioration and loss of articular cartilage. There is currently no treatment to reverse the onset of OA. Thus, we developed a targeted delivery strategy to transfer genes into primary human chondrocytes as a proof-of-concept study. We displayed a chondrocyte-affinity peptide (CAP) on the pIII minor coat protein of the M13 filamentous bacteriophage (phage)-based particle carrying a mammalian transgene cassette under cytomegalovirus CMV promoter and inverted terminal repeats (ITRs) cis elements of adeno-associated virus serotype 2 (AAV-2). Primary human articular chondrocytes (HACs) were used as an in vitro model, and the selectivity and binding properties of the CAP ligand in relation to the pathogenic conditions of HACs were characterized. We found that the CAP ligand is highly selective toward pathogenic HACs. Furthermore, the stability, cytotoxicity, and gene delivery efficacy of the CAP-displaying phage (CAP.Phage) were evaluated. We found that the phage particle is stable under a wide range of temperatures and pH values, while showing no cytotoxicity to HACs. Importantly, the CAP.Phage particle, carrying a secreted luciferase (Lucia) reporter gene, efficiently and selectively delivered transgene expression to HACs. In summary, it was found that the CAP ligand preferably binds to pathogenic chondrocytes, and the CAP.Phage particle successfully targets and delivers transgene to HACs.
Insights
Researchers developed a novel phage-based gene delivery system targeting pathogenic chondrocytes for osteoarthritis treatment. This system demonstrates efficient and selective gene transfer, offering a promising therapeutic strategy for joint degeneration.
Area of Science:
- Biotechnology and Genetic Engineering
- Molecular and Cellular Biology
- Biomedical Engineering
Background:
- Osteoarthritis (OA) is a degenerative joint disease with no current treatments to reverse cartilage loss.
- Effective gene therapy for OA requires targeted delivery of therapeutic genes to affected chondrocytes.
Purpose of the Study:
- To develop and validate a targeted gene delivery system for primary human articular chondrocytes (HACs).
- To assess the selectivity, stability, and efficacy of a phage-based delivery vehicle displaying a chondrocyte-affinity peptide (CAP).
Main Methods:
- Engineered M13 bacteriophage particles displaying a CAP ligand on their surface.
- Constructed phage particles to carry a mammalian transgene cassette (luciferase reporter gene) under CMV promoter and AAV-2 ITRs.
- Evaluated CAP ligand selectivity, phage particle stability (temperature, pH), cytotoxicity, and gene delivery efficiency in vitro using HACs.
Main Results:
- The CAP ligand demonstrated high selectivity for pathogenic HACs.
- The CAP-displaying phage (CAP.Phage) particle exhibited stability across a range of temperatures and pH values.
- CAP.Phage showed no cytotoxicity to HACs and efficiently delivered transgene expression selectively to HACs.
Conclusions:
- The CAP ligand preferentially binds to pathogenic chondrocytes, indicating targeted therapeutic potential.
- The CAP.Phage particle represents a stable, non-cytotoxic, and effective platform for targeted gene delivery to chondrocytes.
- This proof-of-concept study validates a novel strategy for OA gene therapy.
