Ultralong Hydroxyapatite Nanowire/Collagen Biopaper with High Flexibility, Improved Mechanical Properties and Excellent Cellular Attachment

Abstract

Highly flexible hydroxyapatite/collagen (HAP/Col) composite membranes are regarded to be significant for guided bone regeneration application owing to their similar chemical composition to that of natural bone, excellent bioactivity and good osteoconductivity. However, the mechanical strength of the HAP/Col composite membranes is usually weak, which leads to difficult surgical operations and low mechanical stability during the bone healing process. Herein, highly flexible ultralong hydroxyapatite nanowires/collagen (UHANWs/Col) composite biopaper sheets with weight fractions of UHANWs ranging from 0 to 100 % are facilely synthesized. The UHANWs are able to weave with each other to construct a three-dimensional fabric structure in the collagen matrix, providing a strong interaction between UHANWs and an intermolecular force between UHANWs and the collagen matrix. The as-prepared UHANWs/Col composite biopaper exhibits improved mechanical properties and high flexibility. More importantly, the as-prepared highly flexible 70 wt % UHANWs/Col composite biopaper exhibits an excellent cytocompatibility and outstanding cellular attachment performance as compared with the pure collagen and 70 wt % HAP nanorods/Col membranes. In consideration of its superior mechanical properties and outstanding cellular attachment performance, the as-prepared UHANWs/Col composite biopaper is promising for applications in various biomedical fields such as guided bone regeneration.

Hydroxyapatite nanowire/collagen elastic porous nanocomposite and its enhanced performance in bone defect repair

“…49 In addition, the collagen triple helix can entangle with the UHANWs. 18 Thus, the highly exible UHANWs can form the UHANW-collagen nanocomposite brils. The UHANW-collagen nanocomposite brils exhibit high exibility and further interweave with each other to construct the three-dimensional biomimetic porous structure of the UHANWs/Col nanocomposite, which endows the UHANWs/Col porous nanocomposite with signicantly enhanced mechanical properties.…”

“…The 18,33,34 Then, the cross-linked UHANWs/Col porous nanocomposite was rinsed with ethanol and deionized water several times, and dried at 37 C. Similarly, the pure collagen sample as the control sample was prepared under the same conditions but using the pure collagen aqueous solution. The as-prepared pure collagen sample and UHANWs/Col porous nanocomposite were sterilized with 29 kGy of 60 Co radiation before use.…”

“…[16][17][18] Moreover, collagen, as the organic constituent of the bone extracellular matrix, is a promising biomaterial owing to its excellent biocompatibility, cell affinity and biodegradability. [19][20][21] Consequently, the HAP/ collagen (HAP/Col) composite scaffolds can chemically and structurally mimic the natural bone, and have excellent bioactivity, biodegradability and osteoinductive activity.…”

“…11,22,26 Recent reports indicate that the addition of one-dimensional HAP nanostructured materials such as HAP whiskers and nanowires can signicantly improve the mechanical properties and biological responses of the composite biomaterials. 11,18,22,27 More signicantly, the highly exible ultralong HAP nanowires (UHANWs) with lengths of several hundred micrometres were prepared by the calcium oleate precursor solvothermal method by this research group, [28][29][30] and exhibit a great potential in constructing different types of biomaterials with enhanced mechanical properties and improved biological responses. 18,27,31 In addition, the morphology of the UHANWs is similar to that of mineralized collagen brils in the natural bone.…”

“…11,18,22,27 More signicantly, the highly exible ultralong HAP nanowires (UHANWs) with lengths of several hundred micrometres were prepared by the calcium oleate precursor solvothermal method by this research group, [28][29][30] and exhibit a great potential in constructing different types of biomaterials with enhanced mechanical properties and improved biological responses. 18,27,31 In addition, the morphology of the UHANWs is similar to that of mineralized collagen brils in the natural bone. Thus, the UHANWs offer a promising prospect for the construction of biomimetic HAP/Col porous nanocomposite with enhanced mechanical properties and biological responses.…”