Microglia play a critical role in neuroinflammation, a key secondary injury mechanism following traumatic brain injury (TBI). The colony-stimulating factor 1 receptor (CSF-1R) inhibitor PLX5622 has shown promise in suppressing neuroinflammation by depleting microglia, but it lacks specificity in targeting microglia at the injury site. To overcome this limitation, we developed PLX5622 nanoparticles functionalized with the CAQK peptide for lesion-specific targeting and combined them with a hydrogel (GelMA-PPS) that possesses potent reactive oxygen species (ROS) scavenging capabilities. This nanoparticle-hydrogel drug delivery system (GelMA-PPS/P) significantly enhanced the delivery efficiency and therapeutic efficacy of PLX5622 in TBI treatment. Localized administration of this system effectively depleted microglia at the injury site, suppressed neuroinflammation, and reduced the release of inflammatory cytokines. Its ROS scavenging ability was also validated in vitro and in vivo. Together, these effects synergistically improved neurological function recovery in TBI mouse models. This innovative strategy offers a comprehensive and targeted approach to managing neuroinflammation after TBI, providing a promising avenue for advancing TBI therapies.
Nanoparticle technologies offer a non-invasive means to deliver basic fibroblast growth factor (bFGF) for the treatment of spinal cord injury (SCI). However, the inability of bFGF to accumulate at the injury site and inefficient penetration across the blood-spinal cord barrier (BSCB) remain challenges. The present study describes a dual-targeting liposome ( [email protected] &Rp) with injury lesion targeting and BSCB-penetrating capability to deliver bFGF for SCI treatment. The CAQK peptide (Cp) with injury lesion targeting ability and R 2 KC peptide (Rp) with BSCB-penetrating capability were grafted onto the liposomes for a flexible and non-invasive drug delivery systems preparation. Results exhibit that the dual-targeted liposomes could significantly cross the BSCB and accumulate at the injury site. During the early stage of SCI, [email protected] &Rp promotes repair of BSCB and facilitates M2-polarization of macrophages. Regular delivery of [email protected] &Rp increase HUVECs tube formation and angiogenesis, ameliorate the microenvironment of lesion site, suppress the neuronal apoptosis and axonal atrophy in SCI rats. Importantly, continuous treatment of [email protected] &Rp supports the restoration of limb motor function in SCI rats. In summary, this research implies that the injury site-targeting and BSCB-penetrating liposomes could be a promising therapeutic approach for the treatment of SCI.