Surface‐engineered hydroxyapatite nanocrystal/ poly(ε‐caprolactone) hybrid scaffolds for bone tissue engineering

Abstract

To achieve novel polymer/bioceramic composite scaffolds for use in materials for bone tissue engineering, we prepared organic/inorganic hybrid scaffolds composed of biodegradable poly(e-caprolactone) (PCL) and hydroxyapatite (HA), which has excellent biocompatibility with hard tissues and high osteoconductivity and bioactivity. To improve the interactions between the scaffolds and osteoblasts, we focused on surface-engineered, porous HA/ PCL scaffolds that had HA molecules on their surfaces and within them because of the biochemical affinity between the biotin and avidin molecules. The surface modification of HA nanocrystals was performed with two different methods. Using Fourier transform infrared, X-ray diffraction, and thermogravimetric analysis measurements, we found that surface-modified HA nanocrystals prepared with an ethylene glycol mediated coupling method showed a higher degree of coupling (%) than those prepared via a direct coupling method. HA/PCL hybrid scaffolds with a well-controlled porous architecture were fabricated with a gas-blowing/particle-leaching process. All HA/PCL scaffold samples exhibited approximately 80-85% porosity. As the HA concentration within the HA/PCL scaffolds increased, the porosity of the HA/PCL scaffolds gradually decreased. The homogeneous immobilization of biotin-conjugated HA nanocrystals on a three-dimensional, porous scaffold was observed with confocal microscopy. According to an in vitro cytotoxicity study, all scaffold samples exhibited greater than 80% cell viability, regardless of the HA/ PCL composition or preparation method.

XRD, AFM, IR and TGA study of nanostructured hydroxyapatite

“…This application is due to the similarity of the composition of this material with that of the mineral part of bone and tooth 1,2 . The natural bone model presents a combination of organic and inorganic phases with nanometer size (an average length of 50 nm and 25 nm in width) 3 .…”

Functionalization of polyesters with multiple B vitamins

“…Given the universal importance of B vitamins, a general method to attach multiple vitamins to polymers in a single step would be highly beneficial. Overall, covalent attachment of single vitamins, such as folic acid (B 9 ) and biotin (B 7 ), has received much more attention compared with thiamine (B 1 ), B 2 , B 6 , and B 6 precursors such as pyridoxal . In addition, composites with B 2 and B 5 have been electrospun into nanofibers, but covalent attachment of B 5 to polymers presents a new opportunity.…”

Nanostructured fusiform hydroxyapatite particles precipitated from aquaculture wastewater

“…Calcium phosphate based materials are used in numerous applications such as fertilizers (Ferraro, et al, 2013), environmental remediation of waters and soils (Nzihou and Sharrock, 2010;, photocatalysis (Tanaka et al, 2012; and as biomaterials (Vallet-Regí, 2010;Dorozhkin, 2010;Kim, 2011;Zhou and Lee, 2011).…”

“…Interestingly, one of these compounds, hydroxyapatite [HAp, Ca10(PO4)6(OH)2] is commonly used as a bioceramic, due to its osteoconductivity and high biocompatibility properties. HAp also has the ability to promote the formation of new bone tissues, making it a perfect material as a support or filler in bones and teeth (Vallet-Regí, 2010;Kim, 2011;Zhou and Lee, 2011).…”