How Much Physical Guidance is Needed to Orient Growing Axons in 3D Hydrogels?. Issue 21 (5th October 2020)

• Record Type: Journal Article
• Authors: Rose, Jonas C.; Gehlen, David B.; Omidinia‐Anarkoli, Abdolrahman; Fölster, Maaike; Haraszti, Tamás; Jaekel, Esther E.; De Laporte, Laura
• Is Part Of: Advanced healthcare materials. Volume 9:Issue 21(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-05
• Subjects: Anisogel -- cell sensing -- magnetic orientation -- microgels -- nerve regeneration; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1002/adhm.202000886
• Languages: English
• ISSNs: 2192-2640

Abstract

Abstract: Directing cells is essential to organize multi‐cellular organisms that are built up from subunits executing specific tasks. This guidance requires a precisely controlled symphony of biochemical, mechanical, and structural signals. While many guiding mechanisms focus on 2D structural patterns or 3D biochemical gradients, injectable material platforms that elucidate how cellular processes are triggered by defined 3D physical guiding cues are still lacking but crucial for the repair of soft tissues. Herein, a recently developed anisotropic injectable hybrid hydrogel (Anisogel) contains rod‐shaped microgels that orient in situ by a magnetic field and has propelled studying 3D cell guidance. Here, the Anisogel is used to investigate the dependence of axonal guidance on microgel dimensions, aspect ratio, and distance. While large microgels result in high material anisotropy, they significantly reduce neurite outgrowth and thus the guidance efficiency. Narrow and long microgels enable strong axonal guidance with maximal outgrowth including cell sensing over distances of tens of micrometers in 3D. Moreover, nerve cells decide to orient inside the Anisogel within the first three days, followed by strengthening of the alignment, which goes along with oriented fibronectin deposition. These findings demonstrate the potential of the Anisogel to tune structural and mechanical parameters for specific applications. Abstract : A hybrid Anisogel platform to study 3D nerve guidance in function of different rod‐shaped microgel dimensions and aspect ratios. Nerve growth is compared for constant microgel number, volume percent, or distance. Magnetically oriented smaller width microgels lead to enhanced neurite extension while maintaining their ability to induce linear cell and nerve growth and subsequent aligned ECM production.