Investigation of cell infiltration and colonization in 3D porous scaffolds via integrated experimental and computational strategies.

This study aimed to integrate experimental and computational methods to systematically investigate cell infiltration and colonization within porous scaffolds. Poly(lactic acid) discs (Diameter: 6 mm; Thickness: 500 µm) with open pores (Diameter: 400-1100 µm), corners (Angle: 30-120°) and gaps (Distance: 100-500 µm), and cellulosic scaffolds with irregular pores (Diameter: 50-300 µm) were situated in tissue culture plates and cultured with human dermal fibroblasts (HDFs). Both phase contrast and scanning electron microscopy revealed that HDFs initially proliferated on scaffold surfaces, then infiltrated into the porous structures via cell bridging and stacking strategies, which was affected by the initial cell seeding densities, porous structures and culture times. Based on the density-dependent cell growths in two-dimensional cell cultures, power law models were developed to quantitatively simulate cell growths on scaffold surfaces. Model analysis predicted the effect of cell seeding efficiency on cell infiltrations into the porous scaffolds, which was further validated via series cell seeding experiments. The novelty of this research lies in the incorporation of multiple experimental and computational strategies, which enables the mechanistic insights of cell invasion and colonization in porous scaffolds, also facilitates the development of suitable bioprocesses for cell seeding and tissue manufacturing in Tissue Engineering and Regenerative Medicine.

Hydrogel-Based Artificial Synapses for Sustainable Neuromorphic Electronics.

Hydrogels find widespread applications in biomedicine because of their outstanding biocompatibility, biodegradability, and tunable material properties. Hydrogels can be chemically functionalized or reinforced to respond to physical or chemical stimulation, which opens up new possibilities in the emerging field of intelligent bioelectronics. Here, the state-of-the-art in functional hydrogel-based transistors and memristors is reviewed as potential artificial synapses. Within these systems, hydrogels can serve as semisolid dielectric electrolytes in transistors and as switching layers in memristors. These synaptic devices with volatile and non-volatile resistive switching show good adaptability to external stimuli for short-term and long-term synaptic memory effects, some of which are integrated into synaptic arrays as artificial neurons; although, there are discrepancies in switching performance and efficacy. By comparing different hydrogels and their respective properties, an outlook is provided on a new range of biocompatible, environment-friendly, and sustainable neuromorphic hardware. How potential energy-efficient information storage and processing can be achieved using artificial neural networks with brain-inspired architecture for neuromorphic computing is described. The development of hydrogel-based artificial synapses can significantly impact the fields of neuromorphic bionics, biometrics, and biosensing.