Physical properties and cellular responses to crosslinkable poly(propylene fumarate)/hydroxyapatite nanocomposites

Abstract

A series of crosslinkable nanocomposites has been developed using hydroxyapatite (HA) nanoparticles and poly(propylene fumarate) (PPF). PPF/HA nanocomposites with four different weight fractions of HA nanoparticles have been characterized in terms of thermal and mechanical properties. To assess surface chemistry of crosslinked PPF/HA nanocomposites, their hydrophilicity and capability of adsorbing proteins have been determined using static contact angle measurement and MicroBCA protein assay kit after incubation with 10% fetal bovine serum (FBS), respectively. In vitro cell studies have been performed using MC3T3-E1 mouse pre-osteoblast cells to investigate the ability of PPF/HA nanocomposites to support cell attachment, spreading, and proliferation after 1, 4, and 7 days. By adding HA nanoparticles to PPF, the mechanical properties of crosslinked PPF/ HA nanocomposites have not been increased due to the initially high modulus of crosslinked PPF. However, hydrophilicity and serum protein adsorption on the surface of nanocomposites have been significantly increased, resulting in enhanced cell attachment, spreading, and proliferation after 4 days of cell seeding. These results indicate that crosslinkable PPF/HA nanocomposites are useful for hard tissue replacement because of excellent mechanical strength and osteoconductivity.

Influence of carboxymethyl chitin on stability and biocompatibility of 3D nanohydroxyapatite/gelatin/carboxymethyl chitin composite for bone tissue engineering

“…The SEM micrographs demonstrated morphology and microstructure of n-HA/gel and n-HA/gel/CMC composite scaffold which show optimal pore size in accordance to accommodate, infiltrate and proliferate cells. As reported compressive modulus of human trabecular bone, 33,34 our results shows that these composite scaffolds have sufficient mechanical strength and also due to their viscoelasticity in wet condition they can be cut, deform, and fit according to bone defects which allows them to use it in case of bone cyst and large defects with smaller opening. The viscoelastic property of the composites inhibits unexpected breakage of the material and formation of debris from the surface during surgical operation.…”

Solid Free-form Fabrication Technology and Its Application to Bone Tissue Engineering

“…In particular, while the surfaces of many synthetic polymers have low cell affinity, cell-friendly surface HA nanoparticles counteracted the disadvantages of the synthetic polymer PPF/DEF. Yaszemski et al studied the physical properties and cellular responses of poly (propylene fumarate)/HA nanocomposites (26). Liska et al investigated gelatin hydrolysate, which was mixed with reactive diluents, and HA to enhance mechanical strength (23).…”

Morphological and histological analysis on the in vivo degradation of poly (propylene fumarate)/(calcium sulfate/β-tricalcium phosphate)

“…But the strength of porous scaffold is relatively low which limits its application. In order to overcome these limitations, Lee et al successfully fabricated poly(propylene fumarate)/hydroxyapatite (PPF/HA) nanocomposites by crosslinking HA nanoparticles and PPF (Lee et al 2008). The PPF/HA nanocomposites showed excellent mechanical strength and osteoconductivity and may serve as a scaffolding material for bone tissue engineering applications (Lee et al 2008).…”

“…In order to overcome these limitations, Lee et al successfully fabricated poly(propylene fumarate)/hydroxyapatite (PPF/HA) nanocomposites by crosslinking HA nanoparticles and PPF (Lee et al 2008). The PPF/HA nanocomposites showed excellent mechanical strength and osteoconductivity and may serve as a scaffolding material for bone tissue engineering applications (Lee et al 2008). However, HA may limit new bone tissue ingrowth due to its poor in vivo biodegradability (Renooij et al 1985) when PPF/HA is implanted into bone defects though HA possesses excellent biocompatibility and osteoconductive property.…”