A novel gelatin/carboxymethyl chitosan/nano-hydroxyapatite/β-tricalcium phosphate biomimetic nanocomposite scaffold for bone tissue engineering applications

Abstract

Hydroxyapatite (HA) and tricalcium phosphate (TCP) constitute 60% of the content of the bone, and their combination has a better effect on bone tissue engineering than either single element. This study demonstrates a new degradable gelatin/carboxymethyl chitosan (CMC) bone scaffold loaded with both nano-HA and β-TCP (hereinafter referred to as HCP), and freeze drying combined with stir foaming was used to obtain highly connected macropores. Only a few studies have used these components to synthesize a four-component osteogenic scaffold. The aim of this study was to comprehensively assess the biocompatibility and osteoinductivity of the nanocomposites. Three HCP/CMC/gelatin scaffolds were made with different HCP contents: group A (10 wt% HCP), group B (30 wt% HCP), and group C (50 wt% HCP) (the ratio of nano-HA and β-TCP was fixed at 3:2). The scaffolds were macroporous with a high porosity and pore connectivity, as observed by morphological analysis by scanning electron microscopy. Additionally, the pore size of groups A and B was more homogeneous than that of group C. There were no significant differences in physicochemical characterization among the three groups. The Fourier-transform infrared (FTIR) spectroscopy test indicated that the scaffold contained active groups, such as hydroxyl, amino, or peptide bonds, corresponding to gelatin and CMC. The XRD results showed that the phase structures of HA and β-TCP did not change in the nanocomposite. The scaffolds had biodegradation potential and an appreciable swelling ratio, as demonstrated with the in vitro test. The scaffolds were cultured in vitro with MC3T3-E1 cells, showing that osteoinduction and osteoconduction increased with the HCP content. None of the scaffolds showed cytotoxicity. However, cell adhesion and growth in group B were better than those in group A and group C. Therefore, freeze drying combined with a stir foaming method may have a solid component limit. This study demonstrates a novel four-component scaffold via a simple manufacturing process. Group B (30% HCP) had the best characteristics for bone scaffold materials.

Polysaccharide Hydroxyapatite (Nano)composites and Their Biomedical Applications: An Overview of Recent Years

“…A new degradable gelatin@carboxymethyl chitosan bone scaffold loaded with nano-HAp and β-TCP, and freeze drying combined with stir foaming resulted in highly connected macropores . The scaffolds were cultured in vitro with MC3T3-E1 cells (Figure ), showing that osteoinduction and osteoconduction increased with the phosphate content …”

“…Blue fluorescence shows the nuclei stained with DAPI, and red fluorescence shows the cellular F-actin stained with FITC-phalloidin. The magnification was ×400 . Reprinted with permission from ref , Copyright 2022, Frontiers in Chemistry.…”

Effects of Calcium Carbonate Microcapsules and Nanohydroxyapatite on Properties of Thermosensitive Chitosan/Collagen Hydrogels

“…To improve clinical outcomes, bone substitutes should function as bioactive matrices and delivery vehicles for biomolecules and stem cells [ 5 ]. Hydrogels are three-dimensional networks of cross-linked hydrophilic polymers that are insoluble but can absorb large amounts of fluid [ 6 , 7 , 8 ]. Thermosensitive hydrogels have gained broad interest as bone substitutes that can be easily applied in minimally invasive surgery [ 9 , 10 ].…”

“…The β-glycerophosphate (bGP)-cross-linked thermosensitive chitosan/collagen hydrogel has shown great potential as an injectable hydrogel for stem cell encapsulation and bioactive molecule delivery for promoting bone regeneration [ 13 , 14 , 15 , 16 ]. Chitosan and collagen are well-known biomaterials owing to their biocompatibility and osteoconductivity [ 8 , 17 ]. The chitosan/collagen composite improves the mechanical and physical properties of the collagen matrix and exhibits a porous structure that supports growth and osteogenic differentiation of bone marrow stromal cells [ 17 , 18 , 19 ].…”

“…The properties of the thermosensitive chitosan/collagen hydrogel can be modified by adjusting the chitosan/collagen ratio and incorporating a bioceramic. Increasing the chitosan/collagen ratio results in increasingly well-defined porous structures [ 15 ], and incorporating β-tricalcium phosphate (bTCP) increases the mechanical and physical strength of the hydrogels [ 7 , 8 , 16 ]. Additionally, adding an inorganic phase, such as nanohydroxyapatite (nHA), into the hydrogel increases the number of nucleation sites for mineralization, increases the matrix for cell adhesion, and enables integration of the newly formed bone with the surrounding bone [ 20 , 21 ].…”