ABSTRACT
BACKGROUND:Poly(3-hydroxybutyrate) is approved as its excel ent biocompatibility, biodegradability and piezoelectric properties, but there are also some deficiencies, such as high breakability and poor hydrophilicity. METHODS:Poly(3-hydroxybutyrate) was mixed with different mass percentages of nanohydroxyapatite (0, 10%, 20%and 30%) to prepare new composite fibrous scaffolds through electrospinning process. The microstructure, group composition, crystal ine phase distribution, thermal properties and surface wettability of the scaffolds were detected. RESULTS AND CONCLUSION:Under the scanning electron microscope, with the increase of nano-hydroxyapatite content, more and more nano-hydroxyapatite particles were distributed evenly on the composite fiber surface;the fiber surface was basical y covered with nano-hydroxyapatite particles at the content of 30%, and the roughness of the fiber surface also increased. Results from differential scanning calorimetry and X-ray diffraction showed that the nano-hydroxyapatite reduced the crystal inity of poly(3-hydroxybutyrate) and the crystal tacticity, and this phenomenon became more evident with the increase of nano-hydroxyapatite content. Additional y, the higher the content of nano-hydroxyapatite content, the lower the contact angle and the higher the hydrophily. These findings indicate that the nano-hydroxyapatite/poly(3-hydroxybutyrate) ultrafine-fibrous scaffold using electrospinning technology can effectively improve the surface wettability and crystal inity of the material as wel as the material hydrophily and brittleness, and the higher the content of nano-hydroxyapatite, the more obvious the effect.
ABSTRACT
BACKGROUND: Fibrous scaffolds prepared by electrospinning possess similar structure to extracellular matrix, and exhibit convenience in introducing bioactive ceramics into polymer matrices, which have distinct superiority in making bone tissue scaffolds materials.OBJECTIVE: To evaluate the bioactivity of gas-jet/electrospun nanosized hydroxyapatite (nHAP)/poly (3-hydroxybutyrate) (PHB) scaffolds for being used as bone tissue engineering scaffolds.DESIGN, TIME AND SETTING: The in vitro cytology experiment was performed at the State Key Laboratoty of Oral Diseases,Sichuan University between March 2008 and April 2009.MATERIALS: The gas-jet/electrospun PHB and 10% nHAP/PHB scaffolds were prepared.METHODS: Rats bone marrow-derived mescenchymal stem cells were incubated on the nHAP/PHB scaffolds were served as experimental group, incubated on the PHB scaffolds were as control group, and cells incubated on cell culture plate were consided to be blank control group.MAIN OUTCOME MEASURES: mRNA transcript expression of bone-related markers, including alkaline phosphatase, type I collagen, and osteocalcin, were quantified utilizing reverse transcription-polymerase chain reaction (RT-PCR) at day 14 after culture.RESULTS: After 14 days, the bone-related markers were expressed in three groups, and had higher transcript levels in the cells cultured on the nHAP/PHB scaffolds than those on the PHB scaffolds and cell culture plate.CONCLUSION: The gas-jet/electrospun nHAP/PHB scaffolds present good bioactivity in vitro and have the potential to be used in bone tissue engineering.