Reinforcing of Porous Hydroxyapatite Ceramics with Hydroxyapatite Fibres for Enhanced Bone Tissue Engineering

Author(s):  
Lie Feng Liang ◽  
Xiao Yi Han ◽  
Xiao Cai Yan ◽  
Jie Weng

Porous hydroxyapatite (HA) ceramic implants have attracted attention in bone tissue engineering due to their excellent bioactivity and biocompatibility due to their chemical similarity with the mineral component of natural bone. Unfortunately, HA when is formed into porous structures exhibits very low compression strength. In this study, fabrication of porous HA ceramic scaffolds containing HA fibers is presented. The primary aim of the study is to improve mechanical properties of the scaffold by introducing the fiber with uniform component relative to the scaffold. Scanning electron microscopy was used to observe the surface morphology and pore size of the scaffold. X-ray diffraction (XRD) was used to detect the phase composition and crystallinity of the scaffold. The compressive strength was determined using a universal material test machine. The results and the characterizations demonstrate the addition of HA fiber could enhance the uniformity of mechanical properties among samples and also the strength for a given open porosity.

2019 ◽  
Vol 819 ◽  
pp. 9-14 ◽  
Author(s):  
Kanharit Wongsawichai ◽  
Arada Kingkaew ◽  
Aninart Pariyaisut ◽  
Supang Khondee

Bone tissue engineering is an alternative approach to generate bone using biomaterials and cells. Hydroxyapatite (HA) has good biocompatibility, osteoinductivity, and osteoconductivity. However, it has limited utility due to poor mechanical properties and slow degradation rate. To improve mechanical properties and to modify degradation profile, hydroxyapatite was tethered in chitosan (CS) and carboxymethyl cellulose (CMC) complex. Gelatin was incorporated to promote cell attachment and polyvinyl alcohol (PVA) was used to improve mechanical strength of this scaffold. The physico-mechanical and biological properties of these scaffolds were investigated. Fourier transform infrared (FTIR) analysis and X-ray diffraction (XRD) showed the incorporation of hydroxyapatite in polymer matrix. The scaffolds had density, compressive strength, and Young’s modulus in the range of 0.24-0.30 g/cm3, 0.028-0.035 MPa, 0.178-0.560 MPa, respectively. The scaffolds had porosity of 69-91 percent. Higher content of PVA decreased porosity of scaffolds. Scanning electron microscope showed porous microstructure with pore size in the range of 60-183 μm. In vitro test on MC3T3-E1 preosteoblast cells showed negligible cytotoxicity of scaffolds. The data suggested that HA/CS/CMC/gelatin/PVA scaffold has potential applications in bone tissue engineering.


Author(s):  
Hideki Yoshikawa ◽  
Noriyuki Tamai ◽  
Tsuyoshi Murase ◽  
Akira Myoui

Several porous calcium hydroxyapatite (HA) ceramics have been used clinically as bone substitutes, but most of them possessed few interpore connections, resulting in pathological fracture probably due to poor bone formation within the substitute. We recently developed a fully interconnected porous HA ceramic (IP-CHA) by adopting the ‘foam-gel’ technique. The IP-CHA had a three-dimensional structure with spherical pores of uniform size (average 150 μm, porosity 75%), which were interconnected by window-like holes (average diameter 40 μm), and also demonstrated adequate compression strength (10–12 MPa). In animal experiments, the IP-CHA showed superior osteoconduction, with the majority of pores filled with newly formed bone. The interconnected porous structure facilitates bone tissue engineering by allowing the introduction of mesenchymal cells, osteotropic agents such as bone morphogenetic protein or vasculature into the pores. Clinically, we have applied the IP-CHA to treat various bony defects in orthopaedic surgery, and radiographic examinations demonstrated that grafted IP-CHA gained radiopacity more quickly than the synthetic HA in clinical use previously. We review the accumulated data on bone tissue engineering using the novel scaffold and on clinical application in the orthopaedic field.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1319
Author(s):  
Muhammad Umar Aslam Khan ◽  
Wafa Shamsan Al-Arjan ◽  
Mona Saad Binkadem ◽  
Hassan Mehboob ◽  
Adnan Haider ◽  
...  

Bone tissue engineering is an advanced field for treatment of fractured bones to restore/regulate biological functions. Biopolymeric/bioceramic-based hybrid nanocomposite scaffolds are potential biomaterials for bone tissue because of biodegradable and biocompatible characteristics. We report synthesis of nanocomposite based on acrylic acid (AAc)/guar gum (GG), nano-hydroxyapatite (HAp NPs), titanium nanoparticles (TiO2 NPs), and optimum graphene oxide (GO) amount via free radical polymerization method. Porous scaffolds were fabricated through freeze-drying technique and coated with silver sulphadiazine. Different techniques were used to investigate functional group, crystal structural properties, morphology/elemental properties, porosity, and mechanical properties of fabricated scaffolds. Results show that increasing amount of TiO2 in combination with optimized GO has improved physicochemical and microstructural properties, mechanical properties (compressive strength (2.96 to 13.31 MPa) and Young’s modulus (39.56 to 300.81 MPa)), and porous properties (pore size (256.11 to 107.42 μm) and porosity (79.97 to 44.32%)). After 150 min, silver sulfadiazine release was found to be ~94.1%. In vitro assay of scaffolds also exhibited promising results against mouse pre-osteoblast (MC3T3-E1) cell lines. Hence, these fabricated scaffolds would be potential biomaterials for bone tissue engineering in biomedical engineering.


2005 ◽  
Vol 898 ◽  
Author(s):  
Devendra Verma ◽  
Rahul Bhowmik ◽  
Bedabibhas Mohanty ◽  
Dinesh R Katti ◽  
Kalpana S Katti

AbstractInterfaces play an important role in controlling the mechanical properties of composites. Optimum mechanical strength of scaffolds is of prime importance for bone tissue engineering. In the present work, molecular dynamics simulations and experimental studies have been conducted to study effect of interfacial interactions on mechanical properties of composites for bone replacement. In order to mimic biological processes, hydroxyapatite (HAP) is mineralized in presence of polyacrylic acid (PAAc) (in situ HAP). Further, solid and porous composites of in situ HAP with polycaprolactone (PCL) are made. Mechanical tests of composites of in situ HAP with PAAc have shown improved strain recovery, higher modulus/density ratio and also improved mechanical response in simulated body fluid (SBF). Simulation studies indicate potential for calcium bridging between –COO− of PAAc and surface calcium of HAP. This fact is also supported by infrared spectroscopic studies. PAAc modified surfaces of in situ HAP offer means to control the microstructure and mechanical response of porous composites. Nanoindentation experiments indicate that apatite grown on in situ HAP/PCL composites from SBF has improved elastic modulus and hardness. This work gives insight into the interfacial mechanisms responsible for mechanical response as well as bioactivity in biomaterials.


2015 ◽  
Vol 3 (23) ◽  
pp. 4679-4689 ◽  
Author(s):  
Ya-Ping Guo ◽  
Jun-Jie Guan ◽  
Jun Yang ◽  
Yang Wang ◽  
Chang-Qing Zhang ◽  
...  

A bioinspired strategy has been developed to fabricate a hybrid nanostructured hydroxyapatite–chitosan composite scaffold for bone tissue engineering.


Nano LIFE ◽  
2012 ◽  
Vol 02 (01) ◽  
pp. 1250005 ◽  
Author(s):  
BIN DUAN ◽  
MIN WANG ◽  
WILLIAM W. LU

Selective laser sintering (SLS), a rapid prototyping technology, was investigated for producing bone tissue engineering scaffolds. Completely biodegradable osteoconductive calcium phosphate (Ca-P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) scaffolds were successfully fabricated via SLS using Ca-P/PHBV nanocomposite microspheres. In the SLS manufacturing route, the architecture of tissue engineering scaffolds (pore shape, size, interconnectivity, etc.) can be designed and the sintering process can be optimized for obtaining scaffolds with desirable porous structures and mechanical properties. SLS was also shown to be very effective in producing highly complex porous structures using nanocomposite microspheres. To render SLS-formed Ca-P/PHBV scaffolds osteoinductive, recombinant human bone morphogenetic protein-2 (rhBMP-2) could be loaded onto the scaffolds. For achieving a controlled release of rhBMP-2 from scaffolds, surface modification of Ca-P/PHBV scaffolds by gelatin entrapment and heparin immobilization was needed. The immobilized heparin provided binding affinity for rhBMP-2. Surface modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 enhanced the proliferation of human umbilical cord derived mesenchymal stem cells (hUCMSCs) and also their alkaline phosphatase activity. In in vivo experiments using a rabbit model, surface modified Ca-P/PHBV nanocomposite scaffolds loaded with rhBMP-2 promoted ectopic bone formation, exhibiting their osteoinductivity. The strategy of combining advanced scaffold fabrication, nanocomposite material, and controlled growth factor delivery is promising for bone tissue regeneration.


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