Biosilica‐loaded poly(ϵ‐caprolactone) nanofibers mats provide a morphogenetically active surface scaffold for the growth and mineralization of the osteoclast‐related SaOS‐2 cells

Abstract

Bioprinting/3D cell printing procedures for the preparation of scaffolds/implants have the potential to revolutionize regenerative medicine. Besides biocompatibility and biodegradability, the hardness of the scaffold material is of critical importance to allow sufficient mechanical protection and, to the same extent, allow migration, cell-cell, and cell-substrate contact formation of the matrix-embedded cells. In the present study, we present a strategy to encase a bioprinted, cell-containing, and soft scaffold with an electrospun mat. The electrospun poly(ϵ-caprolactone) (PCL) nanofibers mats, containing tetraethyl orthosilicate (TEOS), were subsequently incubated with silicatein. Silicatein synthesizes polymeric biosilica by polycondensation of ortho-silicate that is formed from prehydrolyzed TEOS. Biosilica provides a morphogenetically active matrix for the growth and mineralization of osteoblast-related SaOS-2 cells in vitro. Analysis of the microstructure of the 300-700 nm thick PCL/TEOS nanofibers, incubated with silicatein and prehydrolyzed TEOS, displayed biosilica deposits on the mats formed by the nanofibers. We conclude and propose that electrospun PCL nanofibers mats, coated with biosilica, may represent a morphogenetically active and protective cover for bioprinted cell/tissue-like units with a suitable mechanical stability, even if the cells are embedded in a softer matrix.

Biosilica‐loaded poly(ϵ‐caprolactone) nanofibers: A step closer to bioprinted materials with tunable properties

“…The combination of all the above discussed issues together with the insights provided in this paper [1] not only represent an interesting approach, but can contribute to direct breakthroughs in the field of 3D printing for bone regeneration. This study provides valuable knowledge of the influence of chemical composition on cell/bacterial surface recognition and interactions with biomaterials.…”

“…Müller et al's paper [1] combines several important aspects for the development of biomedical devices, which can be transferred to other fields, such as microbial fuel cells, where interactions between organisms and surfaces are relevant [3]. The role of surface morphology as an important factor for bacterial adhesion and growth [4] is pointed out.…”

“…Particularly elegant is the approach chosen by Müller et al [1] to generate biosilica in situ. The use of silicatein, an enzyme that naturally polymerizes silica under ambient temperature [7] shows a smart way of mimicking nature's approaches to certain processes and the re-application of this knowledge for synthetic purposes.…”

“…The biomaterial PCL and copolymers represent some promising candidates for the construction of 3D scafMüller and co-workers have shown an innovative approach that combines electrospinning of synthetic materials to form electrospun poly(ε-caprolactone) (PCL) nanofiber mats [1]. It is possible to use the PCL nanofibers mats to enzymatically biopolymerize silica.…”

“…It is possible to use the PCL nanofibers mats to enzymatically biopolymerize silica. Silicon is known to improve bone matrix mineralization [2], Müller et al [1], show that by using silicatein it is possible to enhance silicon's natural bone-inducing properties by in situ silica biopolymerization of tetraethyl othosilicate (TEOS), which is already present in the fiber, and using hydrolyzed TEOS as precursor.…”