(b).
| Injection site | Activator | Results |
|---|---|---|
| Lumbar | None | PRP+GHM group decreased IDD and increased PG; PRP+PBS group showed no differences |
| Lumbar | None | PRP+GHM had greater DHI, water content, AGN, and COL II mRNA↑; fewer apoptotic cells in NP |
| Thoracic lumbar | None | PRP promote DHI and osteogenic MSC differentiation |
| Lumbar | None | Preserved IVD fluid content, decreased IVD degeneration |
| Lumbar | Autologous serum and 2 % CaCl2 | Increased cell proliferation, no statistical differences on MRI findings |
| Lumbar | 0.06 ml thrombin | DHI maintained, NP signal intensity maintained; significantly low MRI grading |
| Lumbar | None | PRP moderate effect on MRI, DHI PRP +BMSC: well-preserved ECM, cell density, increased T2 signal intensity, MRi grading, and expression of COL II |
| Lumbar | 100 U thrombin + 10% CaCl2 | T2 signal intensity: PRP > control or PRP+TGF-β inhibitor; histology: PRP-less degeneration, strong COL II staining, and Smad2/3-pathway activated |
| Lumbar | Thrombin+CaCl2 | COL II and PG staining and MRI grade PRP + BMP2 – BMSC > PRP + BMSC > PRP |
Abbreviations: ACT: activation; AGN: aggrecan; BMSC: bone marrow-derived mesenchymal stem cell; BMP2: bone morphogenetic protein 2; COL II: type II collagen; ECM: extracellular matrix; GHM: gelatin hydrogel microsphere; IVD: intervertebral disc; MRI: magnetic resonance imaging; PG: proteoglycan; PRP: platelet-rich plasma; DHI: disc height index.