Although traditional 3D scaffolds or biomimetic hydrogels have been used for tissue engineering and regenerative medicine, soft tissue microenvironment usually has a highly anisotropic structure and a dynamically controllable deformation with various biomolecule distribution. In this study, we developed a hierarchical hybrid gelatin methacrylate-microcapsule hydrogel (HGMH) with Neurotrophin-3(NT-3)-loaded PLGA microcapsules to fabricate anisotropic structure with patterned NT-3 distribution (demonstrated as striped and triangular patterns) by dielectrophoresis (DEP). The HGMH provides a dynamic biomimetic sinuate-microwrinkles change with NT-3 spatial gradient and 2-stage time-dependent distribution, which was further simulated using a 3D finite element model.
View Article and Find Full Text PDFBackground: Olfactory ensheathing cells (OEC), specialized glia that ensheathe bundles of olfactory nerves, have been reported as a favorable substrate for axonal regeneration. Grafting OEC to injured spinal cord appears to facilitate axonal regeneration although the functional recovery is limited. In an attempt to improve the growth-promoting properties of OEC, we transduced prostacyclin synthase (PGIS) to OEC via adenoviral (Ad) gene transfer and examined the effect of OEC with enhanced prostacyclin synthesis in co-culture and in vivo.
View Article and Find Full Text PDFChondroitin sulfate proteoglycans (CSPGs) are glial scar-associated molecules considered axonal regeneration inhibitors and can be digested by chondroitinase ABC (ChABC) to promote axonal regeneration after spinal cord injury (SCI). We previously demonstrated that intrathecal delivery of low-dose ChABC (1 U) in the acute stage of SCI promoted axonal regrowth and functional recovery. In this study, high-dose ChABC (50 U) introduced via intrathecal delivery induced subarachnoid hemorrhage and death within 48 h.
View Article and Find Full Text PDFChondroitin sulfate proteoglycan (CSPG) is a major component of glial scar to restrict axonal regeneration in the lesion site after spinal cord injury (SCI). Chondroitinase ABC (ChABC), a bacteria enzyme, which has been demonstrated to digest the glycosaminoglycan (GAG) side chain of CSPG to promote axonal re-growth across the injured site. Our previous study suggested that long-term delivery of ChABC (1U/ml, injection volume 0.
View Article and Find Full Text PDFWe used a complete spinal cord transection model in which the T8 spinal segment was removed to study the effect of combined treatment of peripheral nerve graft and application of FGF-1 on the glial environment. The combined treatment resulted in reduced astrocytic glial scarring, reactive macrophage gliosis, and inhibitory proteoglycan in the back-degenerated white matter tract. While the macrophage activities in the back-degenerative tract were down-regulated, those in the grafted peripheral nerves and in the distal Wallerian degenerative tracts were not.
View Article and Find Full Text PDF