Chitosan Nano Hydroxyapatite Research Articles

Preparation and Characterization of a Novel Tragacanth Gum/Chitosan/Sr-Nano-Hydroxyapatite Composite Membrane.

It is a great challenge to obtain an ideal guided bone regeneration (GBR) membrane. In this study, tragacanth gum (GT) was introduced into a chitosan/nano-hydroxyapatite (CS/n-HA) system. The effects of different component ratios and strontium-doped nano-hydroxyapatite (Sr-HA) on the physical-chemical properties and degradation behavior of the CS/Sr-n-HA/GT ternary composite membrane were investigated using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle, electromechanical universal tester and in vitro soaking in simulated body fluid (SBF). The results showed that CS could be ionically crosslinked with GT through electrostatic interaction, and Sr-n-HA was loaded via hydrogen bond, which endowed the GT/CS/n-HA composite membrane with good tensile strength and hydrophilicity. In addition, the results of immersion in SBF in vitro showed that CS/n-HA/GT composite membranes had different degradation rates and good apatite deposition by investigating the changes in pH value, weight loss, water absorption ratio, SEM morphology observation and tensile strength reduction. All results revealed that the CS/Sr-n-HA/GT (6:2:2) ternary composite membrane possessed the strongest ionic crosslinking of GT and CS, which was expected to obtain more satisfactory GBR membranes, and this study will provide new applications of GT in the field of biomedical membranes.

The potential of high molecular chitosan nanohydroxyapatite as an irrigant in improving fracture resistance after root canal treatment (In Vitro)

ABSTRACT Teeth after root canal treatment are at a higher risk of fracture than vital teeth. After root canaltreatment, the causes of tooth fracture are multifactorial, both iatrogenic and non iatrogenic. One of them isirrigants, although very useful for disinfection. Irrigants are known to change the chemical components andstructure of the root canal surface dentin by modifying the proportion of calcium and phosphate minerals. Thisresearch is an experimental laboratory study with a post-test-only group research design to analyze the effect ofirrigating solutions of nanohydroxyapatite, high molecular chitosan, NaOCl, and EDTA with their appropriatecombination for the test group on the fracture resistance of teeth after root canal treatment. Root canal treatment wasperformed on 24 mandibular premolars, with the group I; irrigating solution of nanohydroxyapatite, group II;irrigation of nanohydroxyapatite solution with the addition of 0.2% chitosan, group III; irrigation with 2.5% NaOClsolution and 0.2% chitosan solution, group IV; irrigation solution of 2.5% NaOCl and 17% EDTA. ANOVA testshowed a significant difference in fracture resistance (p0.05) between each group. The highest average fractureresistance was seen in group II, namely the irrigation group using a solution of nanohydroxyapatite with theaddition of 0.2% chitosan, which was 363.644 ± 10,896 N. fracture after root canal treatment.KEYWORDS: nanohydroxyapatite, irrigation solution, fracture resistance

Diffusion of calcium ions in one-third of root canals after administration of high molecular Chitosan nanohydroxyapatite medicament (In Vitro)

ABSTRACT Calcium hydroxide is currently the gold standard medicament. Still, it has the disadvantage of leavinga residue on the surface of the root canal wall. Hence, it can interfere with the setting time and adhesion of the sealermaterial to the root canal wall. This study aims to determine the ability of calcium ion diffusion in one-third of theroot canal after administration of nanohydroxyapatite medicament with a different vehicle than calcium hydroxide.This study used 24 mandibular premolars extracted, decorated, and prepared, then grouped into four treatmentgroups. Based on the paired T-test, the study results showed no significant effect of calcium ion diffusion in group B(p = 0.739) on the 7th and 14th days. The ANOVA test results showed no significant difference in calcium ion diffusion between groups A, B, and C. on the 7th day of testing (p=0.773) and the 14th day (p=0.661). In conclusion, there was no effect and difference in the diffusion of calcium ions in the apical third after administration ofmedicament nanohydroxyapatite vehicle bidisstilled water and nanohydroxyapatite vehicle nanochitosan compared tocalcium hydroxide on the 7th and 14th day KEYWORDS: diffusion, calcium hydroxide, ion calcium, nanohydroxyapatite, nano chitosan, vehicle

Preparation and characterization of a novel composite membrane of natural silk fiber/nano-hydroxyapatite/chitosan for guided bone tissue regeneration

Abstract Natural silk fiber (SF) was introduced into the chitosan/nano-hydroxyapatite (CS/n-HA) system to fabricate a novel guided bone tissue regeneration (GBR) membrane. The effect of different treatment methods (degummed, un-degummed, or dissolved SF) and different contents of SF on the properties of the CS/n-HA composite membrane was investigated. Results demonstrated that the degummed SF/CS/n-HA composite membrane with a weight ratio of 2:6:2 possessed the highest mechanical strength, where SF supported the composite membrane as a skeleton frame in the form of primeval state, while the un-degummed SF and dissolved SF had weaker reinforce effect due to the poor interface or poor interaction between SF and CS, and the dissolved SF/CS/n-HA composite membrane displayed the fastest degradation. However, the three SF could all improve the cell biocompatibility of the CS/n-HA composite membrane. Conclusively, the study revealed that degummed SF could in situ reinforce the CS/n-HA composite membrane with a simple and green processing method, which would provide an important guidance significant to develop a novel GBR membrane.

Repair of Osteoporotic Bone Defects Using Adipose-Derived Stromal Cells and Umbilical Vein Endothelial Cells Seeded in Chitosan/Nanohydroxyapatite-P24 Nanocomposite Scaffolds

Background. The cell regeneration and blood supply of bone defect lesions are restricted under osteoporotic pathological conditions, which make the healing of bone defect of osteoporosis still a great challenge. The current therapeutic strategies that mainly inhibit bone resorption are not always satisfactory for osteoporotic bone defects, which make the development of new therapies an urgent need. Methods. Previously, we prepared chitosan/nanohydroxyapatite (CS/nHA) biomimetic nanocomposite scaffolds for controlled delivery of bone morphogenetic protein 2-derived peptide (P24). In this study, we determined the effect of coculturing adipose-derived stromal cells (ADSCs) and human umbilical vein endothelial cells (HUVECs) with the CS-P24/nHA nanocomposite scaffolds on osteoporotic bone defect healing. In vitro mixed coculture models were employed to assess the direct effects of coculture. Results. ADSCs cocultured with HUVECs showed significantly greater osteogenic differentiation and mineralization compared with ADSCs or HUVECs alone. The CS-P24/nHA scaffold cocultured with ADSCs and HUVECs was more effective in inducing osteoporotic bone repair, as demonstrated by micro-computed tomography and histology of critical-sized calvariae defects in ovariectomized rats. Calvariae defects treated with the CS-P24/nHA nanocomposite scaffold plus ADSC/HUVEC coculture had a greater area of repair and better reconstitution of osseous structures compared with defects treated with the scaffold plus ADSCs or the scaffold plus HUVECs after 4 and 8 weeks. Conclusion. Taken together, coculture of ADSCs and HUVECs with the CS-P24/nHA nanocomposite scaffold is an effective combination to repair osteoporotic bone defects.

EVALUATION OF CHITOSAN/HYDROXYAPATITE SCAFFOLD ON THE HEALING OF OSSEOUS DEFECTS IN JAW BONES (CLINICAL STUDY)

INTRODUCTION: The repair and replacement of injured or defective bone is a critical problem in orthopedic treatment. Bone defects in the maxillofacial region are considered a serious health problem. The correct restoration of architecture and function of tissues of this important anatomical region is mandatory. A variety of methods are employed for treating such defects, however, each of the strategies has its own drawbacks. Significant development has been achieved with combining bioceramics and biopolymers. Chitosan/ nano-Hydroxyapatite (CH/nHA) has recently emerged a new strategy for promoting bone regeneration and enhancement of bone healing and remodeling. This composite has increased cell adhesion, cell proliferation, mechanical strength, alkaline phosphatase activity, protein adsorption, type I collagen production as well as expression of other osteogenic differentiation markers.OBJECTIVES: The aim of the present study is to assess the effectiveness of using Chitosan/ nano-Hydroxyapatite composite on healing and regeneration of bony defects of the jaws radiograhicaly by the aid of Cone beam computed tomography.METHODOLOGY: This study was performed on 14 patients having bone defects in their maxilla or mandible due to cysts or tumors. Patients were divided into two groups; test group in which patients had removal of bone lesion leaving bone defects treated with Chitosan/nano-Hydroxyapatite, and control group in which bone defects were left to heal spontaneously. Bone defects were examined radiographically using Cone beam computed tomography.RESULTS: A significant increase in bone density in bone defects treated with Chitosan/nano-hydroxyapatite, as well as significant decrease in bone defect size.

SCANINING ELECTRON MICROSCOPIC EVALUATION OF CHITOSAN NANOHYDROXYAPATITE SCAFFOLD FOR SOCKET HEALING IN RABBITS WITH INDUCED OSTEOPOROSIS

INTRODUCTION: Significant development has been achieved with bioceramics and biopolymer scaffolds in the construction of artificial bone. In the present study, Chitosan– nanohydroxyapatite (CS/nHA) scaffolds have been developed as bone graft substitutes in rabbits with induced osteoporosis.OBJECTIVES: To evaluate the effect of Chitosan- nanohydroxyapatite (CS/nHA) scaffold in bone tissue regeneration of extracted socket in rabbits with induced osteoporosis; using Scanning Electron Microscope and Energy Dispersive x-ray analysis [EDXA].MATERIALS AND METHODS: Twenty NewZealand white female rabbits were randomly divided into 2 equal groups; group A (osteoporosis) with no graft material, and group B (osteoporosis with CS/nHA). After the experimental period the animals were sacrificed at 2 & 4 weeks. The effect of CS/Nha was evaluated using Scanning Electron Microscope and Energy Dispersed x-ray analysis [EDXA]. The data obtained was tabulated and subjected to statistical analysis.RESULTS: Scanning Electron Microscopic results revealed more trabecular bone thickness with regular bone surface, and uniform osteocyte lacunae in the group B (osteoporosis with CS/nHA) than group A (osteoporosis), and these results were proved by EDXA which showed more Ca and P ratio in the group B than group A.CONCLUSIONS: CS/nHA scaffold is considered an effective hard tissue engineering material with sufficient interconnected porosity and mechanical strength to allow cell adhesion, migration, growth and proliferation resulting in good integration with surrounding tissues, and rapid bone healing, thus it might be used in osteoporotic condition.

Fabrication and in-vitro biocompatibility of freeze-dried CTS-nHA and CTS-nBG scaffolds for bone regeneration applications

The thought of biodegradable organic-inorganic composites composed of natural polymer chitosan and ceramic nanoparticles (hydroxyapatite and bioglass) can be considered as a solution for hard tissue engineering. In this paper, we described a comparative assessment of chitosan-nanohydroxyapatite (CTS-nHA) and chitosan-nano-bioglass (CTS-nBG) scaffolds. The dispersion of nanoscaled hydroxyapatite (nHA) and bioglass (nBG) in chitosan remained satisfactory. The freeze-dried composite based CTS-nHA and CTS-nBG scaffolds shown porous structure. The physiochemical and morphological analysis of all samples has been performed through X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The SEM image confirmed the presence of spherically shaped nHA particles of 4.20 μm and irregularly shaped nBG particles of 6.89 μm. The TEM analysis revealed the existence of 165.52 to 255.17 nm sized nHA particles and 167.35 to 334.69 nm sized nBG particles. TEM analysis also showed the interconnected structure of CTS-nHA and CTS-nBG nanocomposites. After seven days' incubation period, the CTS-nHA and CTS-nBG scaffolds shown good mineralization behavior in simulated body fluid (SBF). The CTS-nHA scaffolds exhibited enhanced compressive strength and elastic modulus compared with the CTS-nBG sample. The cell culture experiment revealed that fabricated scaffolds had good compatibility with fibroblast cells (L929, ATCC) and MG-63 which are able to adhere, proliferate, and migrate through the porous structure. All the obtained results clearly recommend that pre-loaded hydroxyapatite and bioglass nanoparticles can enhance the apatite formation. The scaffolds with chitosan, bioglass, and hydroxyapatite have better biomechanical characteristics and allow cell growth. Therefore, these scaffolds can be perfect candidates for various hard tissue engineering applications such as bone regeneration.

Synthesis and Investigation into Apatite-forming Ability of Hydroxyapatite/Chitosan-based Scaffold

Synthesis and Investigation into Apatite-forming Ability of Hydroxyapatite/Chitosan-based Scaffold

High-activity chitosan/nano hydroxyapatite/zoledronic acid scaffolds for simultaneous tumor inhibition, bone repair and infection eradication

Implanted biomaterials combined tumor inhibition and bone repair property are urgently needed to address the huge bone destruction and the high local recurrence following primary surgery in bone tumor therapy. In this work, a high-activity chitosan/nano hydroxyapatite (CS/nHA) scaffold containing zoledronic acid (CS/nHA/Zol) was prepared with a facile method. The prepared CS/nHA/Zol scaffolds exhibited excellent tumor inhibition property towards giant cell tumor of bone (GCT) in vitro through inducing cells apoptosis by up-regulating pro-apoptosis genes expression and reducing the osteoclastic activity of tumor cells by down-regulating osteoclastic genes. Meanwhile, the prepared scaffolds possessed well biocompatibility and osteoinductivity as compared to pure CS/nHA scaffolds. Furthermore, the prepared scaffolds also presented outstanding antibacterial activity against clinical pathogenic S. aureus and E. coli. These overall findings successfully demonstrated the prepared CS/nHA/Zol scaffolds had a multifunction of tumor therapy, bone repair, and antibacterium, which provides a new approach possessed promising advantages in bone tumor therapy.

A novel comby scaffold with improved mechanical strength for bone tissue engineering

Porous scaffold is an integral part of bone tissue engineering. However, low mechanical strength is a major challenge. A biomimetic comby scaffold was designed to get an improvement of strength in this paper. Fabrication of this bone scaffold involved first creating a pore-forming mold by using three-dimensional printing (3DP), which was cast into chitosan/nano-hydroxyapatite (CS/nHA) powders to create an inverse mold. The sacrificial mold and inverse one were then pressed by cold isostatic pressing as a whole in order to enhance the strength. Finally, the wax template was removed, resulting in a scaffold with honeycomb geometry. Compression tests were carried out to evaluate the strength of the scaffold. The behaviors and responses of preosteoblast cells on the scaffold were studied as well. The scaffold with high porosity were found to display improved compressive strength (1.62±0.22MPa) and Young’s modulus (110±22Mpa) approaching the values of cancellous bone. Moreover, MC3T3-E1 cells exhibited good proliferation on the scaffold. The comby scaffold had great application potential in bone tissue engineering. This novel structural bionic approach would offer some new ideas in design and fabrication of porous scaffolds for tissue engineering.

Fabrication of Chitosan-Nano Hydroxyapatite Scaffold for Dental Tissue Engineering

Incorporation of hydroxyapatite (HA) with organic polymer would be used in bone and dental tissue engineering. According to prior researches, because of its chemical similarity to natural bone and dental, this scaffold could improve bioactivity and bone bonding ability. In this research, nano-hydroxyapatite/ chitosan scaffolds were synthesized by two different methods to investigate the effect of different method on scaffold properties. Morphological properties of scaffold such as pore size and fibers diameter were investigated using SEM evaluation, and also bioactivity of scaffolds were measured in simulated body fluid (SBF). The results indicate that Chitosan/nano-Hydroxyapatite scaffold might be a suitable scaffold for tooth engineering while electrospinning techniques present more flexibility and controllable pore size than freeze-drying while with freeze-drying technique percentage of usage hydroxyapatite could be risen up to 40% and shown better macro-mechanical and physical properties.

Facile preparation of biphasic-induced magnetic icariin-loaded composite microcapsules by automated in situ click technology

This research aims to prepare the biphasic-induced magnetic composite microcapsules (BIMCM) as a promising environmental stimuli-responsive delivery vehicle to dispose the problem of drug burst effect. The paper presented a novel automated in situ click technology of magnetic chitosan/nano hydroxyapatite (CS/nHA) microcapsules. Fe3O4 magnetic nanoparticles (MNP) and nHA were simultaneously in situ crystallized by one-step process. Icariin (ICA), a plant-derived flavonol glycoside, was combined to study drug release properties of BIMCM. BIMCM were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Thermal gravimetric analysis/Differential Scanning Calorimetry(TGA/DSC) in order to reveal their component and surface morphology as well as the role of the in situ generated Fe3O4 MNP and nHA. The magnetic test showed the BIMCM were super-paramagnetic. Both in situ generated Fe3O4 MNP and nHA serve as stable inorganic crosslinkers in BIMCM to form many intermolecular crosslinkages for the movability of the CS chains. This makes ICA loaded microcapsules take on a sustained release behavior and results in the self-adjusting of surface morphology, decreasing of swelling and degradation rates. In addition, in vitro tests were systematically carried out to examine the biocompatibility of the microcapsules by MTT test, Wright-Giemsa dying assay and AO/EB fluorescent staining method. These results demonstrated that successful introduction of the in situ click Fe3O4 MNP provided an alternative strategy because of magnetic sensitivity and sustained release. As such, the novel ICA loaded biphasic-induced magnetic CS/nHA/MNP microcapsules are expected to find potential applications in drug delivery system for bone repair.

RETRACTED ARTICLE: Investigating the effects of particle size and chemical structure on cytotoxicity and bacteriostatic potential of nano hydroxyapatite/chitosan/silica and nano hydroxyapatite/chitosan/silver; as antibacterial bone substitutes

The restoration of defective bone tissue and complications related to surgery and fracture site infection are major concerns in orthopedic surgeries. However, it is crucial to develop osteoconductive and bacteriostatic composites. Chitosan/nano hydroxyapatite (CT/n-HAp) powder containing of Ag and Si were prepared by an in situ hybridization method. The aim of this work was to elucidate the effect of size, surface roughness, and chemical structure of mentioned nanocomposites on cytotoxicity and bacteriostatic activity via human osteoblast cells and Escherichia Coli, respectively. Particle size, surface roughness, reactive oxygen specious production, and bioactivity of nanocomposites were investigated by X ray diffraction, atomic force microscopy, DPPH assay, and SEM/UV–Visible spectrophotometer, respectively. Bacterial colony counting test, MTT assay and lactate dehydrogenase (LDH) release were performed as bacteriostatic and biocompatibility tests. The results showed that CT/n-HAp/Ag with smaller particle size in the range of 1–22.6 nm (10.00 ± 0.09 nm) than CT/n-HAp/Si in the range of 3–72.5 nm (18.00 ± 0.14 nm) exhibits higher cell viability and bacteriostatic activity, and less LDH release from cell plasma membrane. Integration of Ag into the nanocomposite hindered the release of Ag+ ions and restricts cytotoxic potential on cells. Higher cytotoxic effect of CT/n-HAp/Si might be related to proton concentration derived from nanocomposite and its chemical structure. In conclusion, the strong bone regeneration potential of CT/n-HAp and good biocompatibility and bacteriostatic activity of CT/n-HAp/Ag make it as potential bacteriostatic bone filler in site of infected bone fracture.

In vivo study of chitosan-natural nano hydroxyapatite scaffolds for bone tissue regeneration

Significant development has been achieved with bioceramics and biopolymer scaffolds in the construction of artificial bone. In the present study, we have developed and compared chitosan–micro hydroxyapatite (chitosan–mHA) and chitosan–nano hydroxyapatite (chitosan–nHA) scaffolds as bone graft substitutes. The biocompatibility and cell proliferation of the prepared scaffolds were checked with preosteoblast (MC3T3-E1) cells. Total Volume (TV), bone volume (BV), bone surface (BS), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) were found to be higher in chitosan–nHA than chitosan–mHA scaffold. Hence, we suggest that chitosan–nHA scaffold could be a promising biomaterial for bone tissue engineering.

Biomimetic chitosan–nanohydroxyapatite composite scaffolds for bone tissue engineering

We describe a comparative assessment of the structure–property–process relationship of three-dimensional chitosan–nanohydroxyapatite (nHA) and pure chitosan scaffolds in conjunction with their respective biological response with the aim of advancing our insight into aspects that concern bone tissue engineering. High- and medium-molecular-weight (MW) chitosan scaffolds with 0.5, 1 and 2 wt.% fraction of nHA were fabricated by freezing and lyophilization. The nanocomposites were characterized by a highly porous structure and the pore size (∼50 to 120 μm) was in a similar range for the scaffolds with different content of nHA. A combination of X-ray diffraction, Fourier transform infrared spectroscopy and electron microscopy indicated that nHA particles were uniformly dispersed in chitosan matrix and there was a chemical interaction between chitosan and nHA. The compression modulus of hydrated chitosan scaffolds was increased on the addition of 1 wt.% nHA from 6.0 to 9.2 kPa in high-MW scaffold. The water uptake ability of composites decreased with an increase in the amount of nHA, while the water retention ability was similar to pure chitosan scaffold. After 28 days in physiological condition, nanocomposites indicated about 10% lower degree of degradation in comparison to chitosan scaffold. The biological response of pre-osteoblasts (MC 3T3-E1) on nanocomposite scaffolds was superior in terms of improved cell attachment, higher proliferation, and well-spread morphology in relation to chitosan scaffold. In composite scaffolds, cell proliferation was about 1.5 times greater than pure chitosan after 7 days of culture and beyond, as implied by qualitative analysis via fluorescence microscopy and quantitative study through MTT assay. The observations related to well-developed structure morphology, physicochemical properties and superior cytocompatibility suggest that chitosan–nHA porous scaffolds are potential candidate materials for bone regeneration although it is necessary to further enhance the mechanical properties of the nanocomposite.