Novel layered double hydroxides-hydroxyapatite/gelatin bone tissue engineering scaffolds: Fabrication, characterization, and in vivo study

Abstract

Developing porous biodegradable scaffolds through simple methods is one of the main approaches of bone tissue engineering (BTE). In this work, a novel BTE composite containing layered double hydroxides (LDH), hydroxyapatite (HA) and gelatin (GEL) was fabricated using co-precipitation and solvent-casting methods. Physiochemical characterizations showed that the chemical composition and microstructure of the scaffolds were similar to the natural spongy bone. Interconnected macropores ranging over 100 to 600μm were observed for both scaffolds while the porosity of 90±0.12% and 92.11±0.15%, as well as, Young's modulus of 19.8±0.41 and 12.5±0.35GPa were reported for LDH/GEL and LDH-HA/GEL scaffolds, respectively. The scaffolds were degraded in deionized water after a month. The SEM images revealed that between two scaffolds, the LDH-HA/GEL with needle-like secondary HA crystals showed better bioactivity. According to the alkaline phosphatase activity and Alizarin red staining results, LDH-HA/GEL scaffolds demonstrated better bone-specific activities comparing to LDH/Gel scaffold as well as control sample (P<0.05). The rabbit adipose stem cells (ASCs) were extracted and cultured, then seeded on the LDH-HA/GEL scaffolds after confluence. Three groups of six adult rabbits were prepared: the scaffold+ASCs group, the empty scaffold group and the control group. The critical defects were made on the left radius and the scaffolds with or without ASCs were implanted there while the control group was left without any treatment. All animals were sacrificed after 12weeks. Histomorphometric results showed that the regeneration of defects was accelerated by scaffold implantation but ASC-seeding significantly improved the quality of new bone formation (P<0.05). The results confirmed the good performance of LDH-HA/GEL scaffold to induce bone regeneration.

Three‐dimensional printed polycaprolactone‐microcrystalline cellulose scaffolds

“…The Figure 4). These values are in the range reported elsewhere for 3D printed polycaprolactone scaffolds 19,26 and in the interval of values reported for spongy bone (20-500 MPa) 27 . As described previously for the flexural properties, the value of the compressive modulus increases when the concentration of MCC is 2% and 5% w/w, but decreases when it is 10% w/w (Figure 4).…”

Layered Double Hydroxides Are Promising Nanomaterials for Tissue Bioengineering Application

“…LDHs have been suggested as biomaterials and an expansion on our knowledge about their biological responses is necessary, mainly addressing comparative aspects of both of them and considering the heterogeneity of cells, as fibroblasts. We have argued to evaluate whether two compositions of LDHs (Mg 2 Al‐Cl and Zn 2 Al‐Cl) are able to influence fibroblast performance and so reinforcing them as potential nanomaterials to be further explored in tissue bioengineering.…”

“…In this context, advances in physics and chemistry area allowed the application of nanoscaled structures on modifying and functionalizing molecules/materials, ameliorating their performance in medical proposes . It is not new the purpose of layered double hydroxides (LDHs) as biomaterial . Recent studies have shown that LDHs are efficient structures in the transport of drugs and assist cellular processes, such as cell differentiation and viability .…”

Bone Regeneration in rat using a gelatin/bioactive glass nanocomposite scaffold along with endothelial cells (HUVECs)

“…The addition of an appropriate polymer to a bioactive ceramic reduces its brittleness while ceramic phase improves bioactivity and stiffness of polymer in the composite structure as a bone scaffold . Gelatin is the hydrolyzed form of collagen which is a major constituent of the organic phase of the bones . In comparison with collagen, due to its biocompatibility (because of its natural origin), biodegradability and very low antigenicity, gelatin has been widely used in the biomedical fields including tissue engineering applications .…”

“…[21][22][23] Gelatin is the hydrolyzed form of collagen which is a major constituent of the organic phase of the bones. 24 In comparison with collagen, due to its biocompatibility (because of its natural origin), biodegradability and very low antigenicity, gelatin has been widely used in the biomedical fields including tissue engineering applications. 25 Incorporation of gelatin with ceramics such as bioactive glasses and hydroxyapatite (HA) can efficiently improve their mechanical properties.…”