Synthesis and Modification of Hydroxyapatite Nanofiber for Poly(Lactic Acid) Composites with Enhanced Mechanical Strength and Bioactivity

To enhance the bioactivity of poly(lactic acid) (PLA), a potential bone repair material, without the lowering of mechanical strength, hydroxyapatite (HA) was introduced in the form of nanofibers as the filler for application in spinal implant materials. HA nanofibers (HANF) with aspect ratio as high as ~100 were synthesized by controlling the starting pH of the reaction. While the tensile and flexural strength of PLA/HANF composites were enhanced compared with those of PLA resin, and were higher for the composites with HANF of higher aspect ratio. To further strengthen the composites, HANF was grafted with PLA chain to form HANF-g-PLA, which could improve the interface between the HANF and matrix PLA. PLA/HANF-g-PLA composites showed even higher tensile and flexural strength than PLA/HANF composites, apparently due to the better dispersion and interfacial adhesion. The composite containing 10 wt% HANF-g-PLA showed the flexural strength of 124 MPa, which was 25% higher than that of PLA resin. In the bioactivity test using a simulated body fluid solution, the rate and uniformity of the apatite growth were observed to be higher for the composites with HANF, and were even higher for those with HANF-g-PLA. This study suggested the possibility of using the PLA/HANF-g-PLA composite in the field of spinal implant materials.

Copper-doped mesoporous bioactive glass endows magnesium based scaffold with antibacterial activity and corrosion resistance

Biodegradable magnesium (Mg) scaffold as bone repair material is desired to own antibacterial function to reduce the risk of bacterial infection. The alloying with antibacterial metal element such as copper...

Osteogenic properties of bioactive sodium titanate/titanium oxide composite coating prepared by anodic oxidation in NaOH electrolyte

Our sodium titanate/titanium oxide coating has excellent osteogenic performance and has potential to be used as a bone repair material.

A co-dispersed nanosystem from strontium-anchored reduced graphene oxide to enhance bioactivity and mechanical property in polymer scaffolds

Poly (L-lactide) (PLLA) is a promising bone repair material owing to its good biocompatibility and natural degradability, but the lacked bioactivity and insufficient mechanical property restrict its further application. Strontium...

Magnesium-based layered double hydroxide nanosheets: a new bone repair material with unprecedented osteogenic differentiation performance

Monolayer magnesium-based layered double hydroxide nanosheets loaded with alendronate were fabricated, which showed unprecedented osteogenic differentiation and bone regeneration performance.

Preparation, bioactivity and mechanism of nano-hydroxyapatite/sodium alginate/chitosan bone repair material

Background: As the major inorganic component of natural bone, nano-hydroxyapatite (n-HA) on its own is limited in its use in bone repair, due to its brittleness. Chitosan (CS) and sodium alginate (SAL) are used to reduce its brittleness and tendency to degradation. However, the compressive strength of the composite is still low, and its biological performance needs further study. Methods: Nano-hydroxyapatite/sodium alginate/chitosan (n-HA/SAL/CS) composite was prepared via an in situ synthesis method. Further, we prepared the n-HA/SAL/CS self-setting bone repair material by mixing n-HA/SAL/CS powder with a curing liquid (20 wt.% citric acid). In addition, the in vitro bioactivity and cell cytotoxicity were also explored. Results: Transmission electron microscopy photos revealed that the n-HA crystals were uniformly distributed throughout the polymer matrix. Infrared IR spectroscopy indicated that the HA interacted with the COO− of SAL and NH2− of CS. The compressive strength of the n-HA/SAL/CS bone cement was 34.3 MPa and matched the demands of weight-bearing bones. Soaking in vitro in simulated body fluid demonstrated that the composite material had reasonably good bioactivity, while cytotoxicity tests indicated that the n-HA/SAL/CS cement could promote cell proliferation and was biocompatible. Conclusions: Compressive strength of n-HA/SAL/CS can satisfy the needs of cancellous bone, and in vitro bioactivity and cytotoxicity tests results indicated that the n-HA/SAL/CS composite could act as an optimal bone repair material.

The improvement of corrosion resistance, biocompatibility and osteogenesis of the novel porous Mg–Nd–Zn alloy

A magnesium scaffold is a promising biodegradable bone repair material.