Magnetically-oriented type I collagen-SiO2@Fe3O4 rods composite hydrogels tuning skin cell growth

Abstract

Conferring orientational order to biological hydrogels constitutes a fruitful strategy for the guided growth of cells. The ability of anisotropic magnetic particles to align along an external magnetic field appears as a particularly, yet poorly explored, strategy to achieve such an orientation in 3D. For this purpose, silica rods coated with magnetite nanoparticles were prepared. When dispersed in a collagen type I solutions, they could be aligned along the magnetic field generated by two plate magnets within five minutes, such an alignment being preserved during hydrogel formation. Both magnetic and rheological measurements evidenced that different structures could be obtained in the absence of the magnetic field and when it was applied parallel or perpendicular to the hydrogel surface. These variations in rods organization also impacted the growth of 2D cultures of Normal Human Dermal Fibroblasts, which was attributed to the higher affinity of the cells for type I collagen compared to silica. These composites have a clear potential as biomaterials associating cell guidance and drug delivery.

In vitro characterization of a novel magnetic fibrin-agarose hydrogel for cartilage tissue engineering

“…More recently, Shi et al reported the preparation of anisotropic collagen hydrogels by magnetic field-induced alignment of SiO2@Fe3O4 rods embedded within the pre-gel solution. [18] These authors found changes in the rheological properties of hydrogels connected to rod alignment and, more interestingly, a statistically significant enhancement of cellular activity in anisotropic hydrogels with respect to Fig. 8.…”

“…[15] Our decision to embed magnetic nanoparticles (MNP) within the chosen FAH was based in previous studies that support the hypothesis of improving the mechanical properties of biomaterials containing MNP. [16] Additionally, other advantages have been reported for magnetic hydrogels in the field of tissue engineering, such as the improvement of cell culture efficiency of some types of cells such as fibroblasts [17,18] and the stimulation of adhesion, proliferation, and differentiation of cells in vitro, and even bone formation in vivo [19][20][21][22].…”

Rational Design and Preparation of Functional Hydrogels for Skin Wound Healing

“… Lyu et al (2021) fabricated flexible ultrasonic patches, in which ultrasound could accelerate the wound healing by activating RAC1 in the dermis and epidermis, thus effectively treating chronic wounds. Shi et al (2020) seeded normal human dermal fibroblasts on an anisotropic magnetic hydrogel, and the cells were oriented to grow under the guidance of the magnetic field, indicating that the anisotropic magnetic hydrogel showed a beneficial effect on the skin tissue regeneration.…”

Paramagnetic Functionalization of Biocompatible Scaffolds for Biomedical Applications: A Perspective

“…Further, anisotropic magnetic scaffold based on collagen was recently reported to influence skin cells [187]. The author synthesized silica rods functionalized with iron oxide nanoparticles (SiO 2 @Fe 3 O 4 ) and incorporated them into a type I collagen-based hydrogel.…”