Preparation and properties of biodegradable polymer/nano-hydroxyapatite bioceramic scaffold for spongy bone regeneration

Abstract

<jats:title>Abstract</jats:title> <jats:p>Biodegradable polymer/bioceramic composite scaffolds can overcome the limitations of conventional ceramic bone substitutes, such as brittleness and difficulty in shaping. To better mimic the mineral components and microstructure of natural bone, a novel nano-hydroxyapatite (nHAp)–chitosan composite scaffold including gelatin and polymer (poly(lactic acid)) with high porosity was developed using a sol-gel method and subsequently lyophilized for efficient bone tissue engineering. The nanocrystalline structure of hydroxyapatite was observed using X-ray diffraction analysis and the composite showed crystallinity due to the presence of nHAp. The pore diameter of the composite containing 5% nHAp was found to be 125 μm, while the composites with 10%, 15%, and 20% nHAp revealed a smaller pore size in the range of 15–28 μm. The highest compressive strength of 5.5 MPa was observed for the 10% nHAp-containing scaffold, whereas thermogravimetric analysis showed 90%–94% degradation at a temperature of 600°C, which demonstrated its excellent thermal stability. Antibacterial and cytotoxicity test results revealed that the composite is resistant toward microbial attack and has low sensitivity in cytotoxicity. The compressive strength data suggests that the composite does not have enough strength as that of human compact bone; however, the highly porous structure as observed in scanning electron microscopy makes it possible for use as an excellent substrate in the spongy bone of humans.</jats:p>

Evaluation of Mechanical Properties of Porous Chitosan/Gelatin/Polycaprolactone Bone Scaffold Prepared by Microwave Foaming Method

“…Coe et al reported that compressive strength is 150 MPa for compact bones, 4–15 MPa for spongy bone, 161.289 MPa for 1MCG-P, 178.239 MPa for 2MCG-P, and 183.966 MPa for 5MCG-P. The proposed bone scaffolds in this study have comparable compressive strength with compact bones [ 35 , 36 , 37 ].…”

Preparation and characterization of diatomite and hydroxyapatite reinforced porous polyurethane foam biocomposites

“…Compared to other biocomposites, a significant increase in 1% HA was observed and the increase was expected to continue after 1 percent due to its compact nature 23 , but the desired increase could not be achieved. It is assumed that when the nanostructure incorporated more than 1 percent of PUF, total homogeneity in the mixture was not achieved.…”

“…4 b, the sample with the lowest total weight loss is PUF containing 5% HA. TGA results noticeably present that the higher the amount of HA in biocomposites, the higher the thermal stability 23 .…”

“…While biodegradable PU is one of the most biocompatible materials employed in scaffolds as temporal extracellular matrices, the major concern about biodegradable polyurethane is absence of bioactive groups that restrict their use 21,22 . An alternative to this issue is to mix PU with bioactive ceramic particles like hydroxyapatite or tricalcium phosphate [22][23][24][25][26] . In this way, the combination of ceramic and polyurethane can increase bioactivity as well as improve the mechanical properties of porous scaffolds 27 .…”

Recent advances in natural polymer-based hydroxyapatite scaffolds: Properties and applications

“…Furthermore, chitosan by itself is not osteoconductive and thus combined with biopolymers or bioactive nanoceramics such as SiO 2 , ZrO 2 , TiO 2 , HAP, etc. that enhances mechanical potency and structural reliability of chitosan-based composites for bone tissue engineering applications [117][118][119][120][121].…”