Colloidal multiscale porous adhesive (bio)inks facilitate scaffold integration

Abstract

Poor cellular spreading, proliferation, and infiltration, due to the dense biomaterial networks, have limited the success of most thick hydrogel-based scaffolds for tissue regeneration. Here, inspired by whipped cream production widely used in pastries, hydrogel-based foam bioinks are developed for bioprinting of scaffolds. Upon cross-linking, a multiscale and interconnected porous structure, with pores ranging from few to several hundreds of micrometers, is formed within the printed constructs. The effect of the process parameters on the pore size distribution and mechanical and rheological properties of the bioinks is determined. The developed foam bioinks can be easily printed using both conventional and custom-built handheld bioprinters. In addition, the foam inks are adhesive upon in situ cross-linking and are biocompatible. The subcutaneous implantation of scaffolds formed from the engineered foam bioinks showed their rapid integration and vascularization in comparison with their non-porous hydrogel counterparts. In addition, in vivo application of the foam bioink into the non-healing muscle defect of a murine model of volumetric muscle loss resulted in a significant functional recovery and higher muscle forces at 8 weeks post injury compared with non-treated controls.

Cell Infiltrative Inner Connected Porous Hydrogel Improves Neural Stem Cell Migration and Differentiation for Functional Repair of Spinal Cord Injury

“…Further, motor neuron progenitor genes including HB9, ISLET1, and MAP2 were noticeably increasing, while GFAP was decreasing in the porous group, indicating that the majority of NSCs were converted into relatively mature neurons/motoneurons. Previous research has shown that different cell types may require different microporous sizes within hydrogel for maximum tissue growth, with the optimal average pore size ranging from a few to hundreds of micrometers . In the present study, with an average diameter of 168 ± 71 μm and suitable modulus, the migration and differentiation rates of NSCs were enhanced.…”

“…Previous research has shown that different cell types may require different microporous sizes within hydrogel for maximum tissue growth, with the optimal average pore size ranging from a few to hundreds of micrometers. 31 In the present study, with an average diameter of 168 ± 71 μm and suitable modulus, the migration and differentiation rates of NSCs were enhanced.…”

Engineering a highly elastic bioadhesive for sealing soft and dynamic tissues

“…At each time point (1, 2, 3, and 4 days), the samples were removed from the solution and weighed ( W 2 ) to determine the mass changes after degradation. The normalized mass (%) 43 was calculated using Equation (2): …”

One‐Step Bioprinting of Multi‐Channel Hydrogel Filaments Using Chaotic Advection: Fabrication of Pre‐Vascularized Muscle‐Like Tissues

“…[66,67] Previous reports have shown that the presence of microarchitecture, such as pores, may increase the water holding capacity of scaffolds. [68][69][70] We assessed whether hollow channels generated by chaotic printing may play a similar role by evaluating the swelling ratio of filaments printed using 3 and 5 KSM elements within the printhead. In this experiment, the permanent and fugitive inks were high-viscosity alginate and pluronic, respectively.…”