Loading...
| Friend's email | |
| Your name | |
| Your email | |
| enter code | |
This page was sent successfuly
Loading of Drug and Nanostructured Coating on Dental Implant
Abbaspour Ghomi, Somayya | 2014
2478
Viewed
- Type of Document: M.Sc. Thesis
- Language: English
- Document No: 46695 (57)
- University: Sharif University of Technology, International Campus, Kish Island
- Department: Science and Engineering
- Advisor(s): Sadrnezhaad, Khatiboleslam
- Abstract:
- The aim of this project is to load analgesic drug; Paracetamol on dental implant. The implant is titanium alloy (Ti-6Al-4V). There are two kinds of samples of anodized and HA coated onto anodized. They are in the shape of the sheets in this study. The electrodeposition and anodization carried out in order to treat the two samples. Nanotubes were formed during anodic oxidation of the samples in the 1M Ammonium sulfate (NH₄)₂SO4 and 5wt% Ammonium fluoride NH4F electrolyte. They are expected to play role of carrier for the model drug; paracetamol. The results showed that HA anodized Ti-6-4 has the ability to hold higher amounts of drug and also can keep the drug for a longer time than the anodized sample. Accordingly, the drug loading time for the anodized Ti alloy should be around 30 minutes but for the HA anodized it can continue to 45 minutes. Drug release behavior of the drug loaded samples was also tried to be determined by immersing the drug loaded samples into the release media; PBS (Phosphate Buffered Saline). XRD analysis proved the formation of HA on HA anodized sheet and a strong reflection at about 25.5 ° was observed. SEM micrograph revealed the formation of the nanotube arrays on the substrates. Mechanical properties were also evaluated by TriboScope system. The hardness and the elastic modulus of the samples were calculated by this examination and the anodized sample with 0.39 GPa showed higher hardness than HA anodized one with 0.12 GPa. Biocompatibility tests carried out using MTT assay in order to find the viability of different kinds of treated samples and also alizarin red staining was applied to observe the osteogenesis
- Keywords:
- Drugs ; Dental Implant ; Titanium Alloy ; Hydroxyapatite ; Nanocarrier ; Nanostructured Coating ; Release Mechanism
Digital Object List-
محتواي کتاب - view
Bookmark- 1.1 Drugs
- 1.1.1 Drug-Material Interaction
- 1.1.2 Carrier Materials Used For DDS
- 1.1.3 Encapsulating Architectures
- 1.1.4 Drug Release
- 1.1.4.1 Release Profile
- 1.1.4.2 Burst Release Effect
- 1.1.4.3 Drug Release from Microemulsion
- 1.1.4.4 Drug Release from Matrices
- Fig. 1.4 The most important phenomena affecting drug release from polymeric matrices are: (1) matrix swelling; (2) erosion; (3) drug dissolution; (4) recrystallization; (5) drug diffusion; (6) drug/matrix structure interactions; (7) drug distribution and concentration inside the matrix; (8) matrix geometry (cylindrical, spherical, etc.); and (9) matrixes polydispersion in the case of delivery systems made up by an ensemble of mini matrixes [10].
- 1.1.4.5 Factors that Affect the Drug Release
- 1.1.5 The Drug That’s Been Used In This Project; Paracetamol
- 1.2 Coating Techniques
- 1.3 Anodization
- 1.3.1 Basic Properties of Anodization Process
- 1.3.1.1 Anodization of Titanium
- 1.3.1.2 Influence of Processing Parameters
- 1.3.1.3 Creation of Rough Surfaces
- 1.3.1.4 Creation of Nano-Roughness
- 1.4 Titanium
- 1.4.1 Basic Properties
- 1.4.2 Alloy Classification
- 1.4.3 Titanium Implants
- 1.5 Biomaterials
- 1.5.1 Hydroxyapatite
- 1.5.1.1 Bioactivity
- 1.5.1.2 Crystallographic Structure
- 1.6 Implants
- 1.6.1 Dental Implants
- 1.6.1.1 Nanotechnology on Dental Implants
- 1.6.1.2 Nanoscale Surface Modification
- Surface properties play a remarkable role in biological interactions. Particularly, the nanometersized roughness and the chemistry have a key role in the interactions of surfaces with proteins and cells. These early interactions will in turn condition the late tissue integration. In this case, different methods have been reported for increasing bone healing around metal implant modifying surface roughness has been shown to enhance the bone to implant contact and improve their clinical performance Grid-blasting, anodization, acid-etching, chemical grafting, and ionic implantation were the most commonly used methods for modifying surface roughness of metal implants. Moreover, TiO2 nanotubes on Ti improved the production of alkaline phosphatase (ALP) activity by osteoblastic cells. Particularly, nanotubes with a diameter of 100 nm upregulated level of ALP activity as compared to 30–70 nm diameter nanotube surfaces. Another approach for improving osseointegration of dental implants is to apply a CaP coating having osteoconductive properties. Different methods have been developed to coat metal implants with CaP layers such as plasma spraying, biomimetic, and electrophoretic deposition. Nevertheless, plasma-sprayed HA-coated dental implants have been related to clinical failures due to coating delimitation and heterogeneous dissolution rate of deposited phases. An electrochemical process which consists of depositing CaP crystals from supersaturated solutions has been proposed for coating titanium implants with CaP layers. Osteoclast cells are also able to resorb the CaP coatings and activate osteoblast cells to produce bone tissue. As the result, these CaP coatings promote a direct bone-implant contact without an intervening connective tissue layer leading to a proper biomechanical fixation of dental implants. A current strategy is to modify titanium-based implants to possess nanometer surface features considering that natural bone is a nanostructured material. It is important to note that type I collagen (organic matrix of bone) is a triple helix 300 nm in length, 0.5 nm in width, and periodicity of 67 nm while HA (inorganic mineral phase of bone) are approximately 20 to 40 nm long. Besides, HA crystals are uniquely patterned within the collagen network. These indicate that bone cells may be used to an environment in nano-scale rather than micro-scale. Recently, human osteoblasts were observed to initially adhere to grain boundaries on both nanophase and conventional titanium; greater osteoblast adhesion was found on nanophase titanium that possessed more grain boundaries on the surface. Nevertheless, the mechanical strength of this nanophase titanium (compacts of nanoparticles) was not high enough for use as a bulk material like titanium alloys through metallurgy techniques. Proper nanometer surface modification methods for current titanium-based implants are, then, being actively pursued [74,75,76,77,78].
- 1.7 Point of View
- 2.1 Titanium Alloy Samples
- 2.2 Coating Process
- 2.2.1 Anodization of Ti-6Al-4V
- 2.2.2 Electro-Deposition of Hydroxyapatite on the Anodized Ti-6Al-4V
- 2.2.3 Coating Analysis
- 2.3 Drug Loading
- 2.4 Biocompatibility
- 2.4.1 MTT Assay
- 2.4.2 SEM
- 2.4.3 Alizarin Red
- 3.1 Structural and Morphological Characterization
- 3.1.1 Mechanism of Electrochemical (Anodic Oxidation)
- 3.2 Phase Composition
- 3.3 Nanoindentation
- 3.4 Drug Loading Study; Adsorption and Desorption (Release) Behavior
- 3.5 Drug Release behavior
- 3.5.1 Drug release in PBS results
- 3.6 Biocompatibility of Titanium
- 3.6.1 Biocompatibility Tests Results