Platelet-Rich Plasma Modulates Neuroinflammation in an iPSC Model of Sensory Neurons and Microglia

Neuropathic pain (NP) is driven by neuroimmune interactions where in activated microglia release pro-inflammatory mediators that sustain central sensitization. Platelet-rich plasma (PRP) is a promising therapy, but its efficacy depends on its biochemical composition. This study aimed to evaluate how modifying the molecular profile of PRP influences its capacity to modulate neuroinflammation in a human-derived co-culture model. We compared standard PRP (sPRP) and balanced protein-concentrate plasma (BPCP), enriched in extraplatelet molecules, using an iPSC direct co-culture of sensory neurons (hSNs) and microglia (hMG). Neuroinflammation was induced for 24 h with serum-free (SF) or 10% sPRP or BPCP supplementation. Neuroinflammation, microglial activation, apoptosis, and neuronal plasticity were analyzed via RT-qPCR and Luminex. Both formulations attenuated pro-inflammatory mediators. However, BPCP demonstrated superior suppressive efficacy, reducing the levels of major cytokines (IL-1β, TNF-α, IL-6, IL-8) by half as compared to sPRP. BPCP significantly decreased IL-6, IL-8, and MCP-1 protein levels; kept microglial activation markers (CD86, CTSS) downregulated; and downregulated the apoptotic cascade (BAX, CASP9, CASP3). Conversely, sPRP displayed a distinct pro-resolving and neuroprotective trend, upregulating IL-10 and TGF-β1 and rescuing the expression of SLC12A5 (KCC2), which regulates neuronal excitability. sPRP and BPCP modulated neuroinflammation via complementary mechanisms. BPCP acted as an immunomodulatory shield suppressing macro-inflammation, while sPRP drove inflammation resolution and neuroplastic rescue.