Hierarchical microchannel architecture in chitosan/bioactive glass scaffolds via electrophoretic deposition positive‐replica

Abstract

One of the main challenges in the design of scaffolds for cortical bone regeneration is mimicking the highly oriented, hierarchical structure of the native tissue in an efficient, simple, and consistent way. As a possible solution to this challenge, positive replica based on electrophoretic deposition (EPD) was here evaluated as a technique to produce organic/inorganic scaffolds with oriented micro‐porosities mimicking Haversian canals diameter and spacing. Two different sizes of 45S5 bioactive glass (BG) powders were chosen as inclusions and loaded in a chitosan matrix via EPD on micro‐patterned cathodes. Self‐standing chitosan scaffolds, with a homogeneous dispersion of BG particles and regularly‐oriented micro‐channels (ϕ = 380 ± 50 μm, inter‐channel spacing = 600 ± 40 μm), were obtained. In vitro analysis in simulated body fluid (SBF) revealed the ability to induce a deposition of a homogenous layer of hydroxyapatite (HA), with Ca/P nucleation reactions appearing kinetically favored by smaller BG particles. Cell interaction with hybrid scaffolds was evaluated in vitro with bone osteosarcoma cells (SAOS‐2). The osteoconductive potential of EPD structures was assessed by evaluating cells proliferation, viability and scaffold colonization. Results indicate that EPD is a simple yet extremely effective technique to prepare composite micro‐patterned structures and can represent a platform for the development of a new generation of bone scaffolds. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.

Aging of Bioactive Glass-Based Foams: Effects on Structure, Properties, and Bioactivity

“…Several efforts have addressed the manufacturing of such structures through technologies enabling the large-scale production of highly reproducible and reliable implants. Different comprehensive research works [10,11,12] and reviews [9,13,14] of all technological aspects relevant to the fabrication of bioactive glass scaffolds and the resulting properties have been published, elucidating the importance of selecting processes that match the biological needs during tissue regeneration [15]. A bioactive glass-ceramic scaffold has been recently developed using a process combining powder and polymer foam technologies, with the resulting scaffolds possessing structure and porosity ideal for bone reconstruction [16].…”

Nano-Modified Titanium Implant Materials: A Way Toward Improved Antibacterial Properties

“…The coating has excellent adhesive strength with the base material which can effectively promote the formation of apatite, and also it has a favorable biological activity. In addition, there are several related studies on the application of electrophoretic deposition technology to prepare bioactive glass coatings with various biological activities ( Ur Rehman et al, 2018 ; Ghalayani Esfahani et al, 2019 ). There are also studies about the fabrication of antibacterial coatings by this method ( Braem et al, 2017 ; Bakhshandeh and Amin Yavari, 2018 ; Ning et al, 2019 ; Thinakaran et al, 2020 ).…”

Recent Advances in Regenerative Tissue Fabrication: Tools, Materials, and Microenvironment in Hierarchical Aspects

“…Despite all the benefits of hierarchical structures, their manufacture is still a challenge to tissue engineers. [ 213 ] One must have a fair amount of knowledge about the structure of the target tissue to be able to mimic its hierarchical design from the molecular to the macroscopic level. A common example is the structure of bone in which nanoscale attributes affect cell binding, microscale components affect cell migration, and macroscale structures affect the mechanical anisotropy of the bone.…”

“…[ 214 ] One method to enhance the hierarchical structure to mimic the Haversian canals in bone is to use electrophoretic deposition of a positive replica of chitosan/bioactive‐glass scaffolds to create similar micropores, thus augmenting osteoconduction. [ 213 ] Taking a further step based on recent technical advancements, researchers have successfully manufactured hierarchically structured 3D‐printed scaffolds called “μCh.” [ 215 ] The interconnected 3D hierarchical structure in the microchannels can provide more space for efficient nutrient transport and metabolic waste disposal, thus enhancing osteogenesis. [ 216 ] Moreover, hierarchical structures with appropriate micropatterns can efficiently manipulate macrophage response by either increasing or reducing the macrophage polarization, thus altering the osteogenic differentiation of human bone marrow stromal cells.…”