Directing the organization of cells into a tissue with defined architectures is one use of biomaterials for regenerative medicine. To this end, hydrogels are widely investigated as they have mechanical properties similar to native soft tissues and can be formed in situ to conform to a defect. Herein, we describe the development of porous hydrogel tubes fabricated through a two-step polymerization process with an intermediate microsphere phase that provides macroscale porosity (66.5%) for cell infiltration. These tubes were investigated in a spinal cord injury model, with the tubes assembled to conform to the injury and to provide an orientation that guides axons through the injury. Implanted tubes had good apposition and were integrated with the host tissue due to cell infiltration, with a transient increase in immune cell infiltration at 1 week that resolved by 2 weeks post injury compared to a gelfoam control. The glial scar was significantly reduced relative to control, which enabled robust axon growth along the inner and outer surface of the tubes. Axon density within the hydrogel tubes (1744 axons/mm2) was significantly increased more than 3-fold compared to the control (456 axons/mm2), with approximately 30% of axons within the tube myelinated. Furthermore, implantation of hydrogel tubes enhanced functional recovery relative to control. This modular assembly of porous tubes to fill a defect and directionally orient tissue growth could be extended beyond spinal cord injury to other tissues, such as vascular or musculoskeletal tissue. STATEMENT OF SIGNIFICANCE: Tissue engineering approaches that mimic the native architecture of healthy tissue are needed following injury. Traditionally, pre-molded scaffolds have been implemented but require a priori knowledge of wound geometries. Conversely, hydrogels can conform to any injury, but do not guide bi-directional regeneration. In this work, we investigate the feasibility of a system of modular hydrogel tubes to promote bi-directional regeneration after spinal cord injury. This system allows for tubes to be cut to size during surgery and implanted one-by-one to fill any injury, while providing bi-directional guidance. Moreover, this system of tubes can be broadly applied to tissue engineering approaches that require a modular guidance system, such as repair to vascular or musculoskeletal tissues.

• Klíčová slova
• Axon elongation, Modular biomaterial, Spinal cord injury, Tissue repair,
• MeSH
• axony účinky léků   patologie   MeSH
• hydrogely farmakologie   MeSH
• jizva patologie   MeSH
• lokomoce účinky léků   MeSH
• maleimidy chemie   MeSH
• mikrosféry MeSH
• myelinová pochva účinky léků   metabolismus   MeSH
• myši inbrední C57BL MeSH
• neuroglie patologie   MeSH
• polyethylenglykoly chemie   MeSH
• polymerizace MeSH
• poranění míchy patologie   patofyziologie   MeSH
• poréznost MeSH
• reagencia zkříženě vázaná chemie   MeSH
• regenerace nervu účinky léků   MeSH
• tkáňové podpůrné struktury chemie   MeSH
• zadní končetina účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• hydrogely MeSH
• maleimide MeSH Prohlížeč
• maleimidy MeSH
• polyethylenglykoly MeSH
• reagencia zkříženě vázaná MeSH

Multimodal probes, which can be simultaneously visualized by multiple imaging modalities, enable the cellular uptake, intracellular fate, biodistribution and elimination to be tracked in organisms. In this study, we report the synthesis of crystalline WO3 and CaWO4 doped with Eu3+ or Tb3+ nanoparticles (size range of 10-160 nm) coated with polysaccharides, and these nanoparticles constitute a versatile easy-to-construct modular toolbox for multimodal imaging. The particles adsorb significant amounts of polysaccharides from the solution, providing biocompatibility and may serve as a platform for labeling. For WO3, the sorption is reversible. However, on CaWO4, stable coating is formed. CaWO4/Tb3+ coated with chemisorbed dextrin, mannan, guar gum and sodium alginate successfully underwent endocytosis with HepG2 cells and was visualized using confocal microscopy.

• Klíčová slova
• Adsorption of polysaccharides, Doped calcium tungstate nanoparticles, HepG2 cell targeting, Tungsten oxide nanoparticles,
• MeSH
• biokompatibilní materiály chemie   MeSH
• buňky Hep G2 MeSH
• endocytóza fyziologie   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• luminiscence * MeSH
• nanočástice aplikace a dávkování   chemie   účinky záření   MeSH
• polysacharidy chemie   MeSH
• terbium chemie   MeSH
• wolfram chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• polysacharidy MeSH
• terbium MeSH
• wolfram MeSH