Antigliotic guiding regenerative gel: a bioactive hydrogel platform for peripheral nerve and spinal cord repair

Peripheral nerve injury (PNI) and spinal cord injury (SCI) impose a major burden of traumatic neurological disability worldwide. Autologous nerve grafting, the current gold standard, achieves meaningful recovery in only 81.6% of repairs (2023 meta-analysis, n = 1,559), while hollow nerve graft conduits achieve only 62.2% (p < 0.05), with performance declining sharply beyond 20-30 mm gaps. Passive scaffolds cannot counter the inhibitory post-injury microenvironment of reactive gliosis, chondroitin sulfate proteoglycan (CSPG) deposition, oxidative stress, and myelin-associated inhibitors, which actively collapse regenerating axon growth cones. This review traces the conceptual and developmental logic of a family of bioactive hydrogels, "neurogels", designed as active modulators of the regenerative microenvironment rather than passive bridges. We organize the review around the scientific problem: the biological barriers that passive scaffolds cannot address; the design rationale for a hyaluronic acid (HA)-based neurogel bearing a biomimetic laminin-derived peptide (LDP-916), an antioxidant, and an antigliotic immunomodulator; the formulation evolution from the original Guiding Regenerative Gel (GRG; HA + LDP-916 + recombinant superoxide dismutase 1, SOD1) to the current Antigliotic Guiding Regenerative Gel (AGRG; HA + LDP-916 + DL-α-tocopherol + glatiramer acetate); and the preclinical evidence base. An in vitro ³⁵S-glycosaminoglycan candidate-selection screen in activated astrocytes identified several antigliotic agents; translational barriers of the top-ranked biologics (bacterial origin and thermolability of chondroitinase ABC; blood-brain barrier impermeability of anti-NogoA antibody) motivated selection of glatiramer acetate, the active copolymer of Copaxone (a clinically validated multiple sclerosis drug), and replacement of SOD1 by DL-α-tocopherol for manufacturing and stability reasons. AGRG increased neurite length by approximately 78% in vitro relative to control, showed electrophysiological performance comparable to or exceeding autograft in a 25 mm chronic rabbit PNI model at 40 weeks, and promoted myelinated axon regrowth in acute and chronic rat SCI. A recently completed 15 mm rat sciatic critical-gap study comparing AGRG to autograft provides supportive internal data; because this dataset has not yet completed independent peer review, its findings are described in general terms and are not used as a basis for definitive efficacy claims. Regulatory-enabling studies are being pursued by Maxonis Ltd. in preparation for an FDA pre-IND interaction.