Papers by Keyword: Biomaterial

Abstract: Aloe Vera and sea cucumber are the natural material which has been used widely in bio-medical field in Malaysia, especially for wound healing purposes due to its therapeutic effects. Recently, thin films which can absorb acceptable amount of fluid has been gaining attentions in biomaterial wound dressing applications. Hence, the incorporation of these natural materials in the fabrication of the thin films were investigated regarding the fluid intake capacity under the condition of being in contact with deionized water and pseudo-wound exudate. Three types of films made of different compositions of Aloe Vera and sea cucumber were prepared and evaluated. The morphology of the films was analysed using the Scanning Electron Microscopy (SEM) evaluation and the fluid intake capacity through the Free Swell Absorptive Capacity test. Results showed the variety of fluid intake capacity of different type of the film after being immersed in both solutions. The morphological structure of each film also varied from one another. The result also indicated that the Aloe Vera film held the adequate fluid intake capacity without any degradation behaviour.

Abstract: The aim of this research is to synthesis biopolymeric materials from hydroxyethyl cellulose (HEC) (5 wt. %) blended with sodium alginate (SA) (10 wt. %) at 1:1 ratio fabricated by using freeze-drying technique. The HES/SA was treated with simulated body fluid (SBF) by immersion technique through the depositing of calcium phosphate on the scaffold’s surfaces. All scaffolds were characterizing by using field emission electron microscope (FESEM), attenuated total reflectance-Fourier infrared transform (ATR-FTIR), and thermogravimetric analysis (TGA). The FESEM images results displayed interconnected porous structure with diameter ranging from 40 to 400 μm with average apatite diameter in range of 95 nm – 148 nm. The ATR-FTIR results exhibit possible interactions between hydroxyl groups of HEC, SA and apatite groups of the scaffolds. The TGA results showed four different regions of mass losses, represents the amorphous transition temperature and water disposal, side-chain bond breaking, pyrolysis of SA and dihydroxylation behaviour of calcium phosphate, respectively. Cell-scaffolds interaction demonstrated that human fetal osteoblast (hFOB) cells differentiated and spread well on scaffolds with better cell proliferation and attachment was more prominent on HEC/SA treated with SBF. Since these biocompatible and biodegradable scaffolds showed promising results, these scaffolds could be adopted for the design of next-generation tissue-engineered bone grafts.

Abstract: The current state of technology for 3D printing with biomaterials is based on the extrusion of viscous materials. Mostly, extrusion heads utilize pneumatic pressure systems or stepper motors to force the substrate onto a surface. These methods are well developed for high viscouse materials. However, processing low viscous liquids may cause leakages in the system. This could be solved by applying continuous extrusion. Additionally, in order to process gelable substrates, such as gelatine and agar, tempered print heads in combination with a multi stage tempering system are required to prevent the system from clogging. The ongoing work presented in this paper focuses on the development of an extrusion system, which should be able to process multiple viscosities of gelatine sequentially. In order to achieve this, several measurements to examine the properties, as well as the material parameters of different biomaterials are performed. In this process gel point, force resistance and elasticity are the factors of particularly interest. Due to their ability to gel and their availability, the most relevant biomaterials are gelatine and agar. Using this data, an extrusion system involving a peristaltic pump, a heated tube and a nozzle, has been developed. The next step envisaged is to calibrate the extruder based on the obtained data and finally to validate the printing process by printing simple geometric structures. Assuming that a positive evaluation is obtained, the printing system will be tested for printing first organic test structures from patient data using the examined biomaterials.

Abstract: Biomaterials can be used in several areas of regenerative bioengineering, and is a viable option in the repair of bone injuries. A number of different types of biomaterials have been studied in relation to bone repair. Ceramics such as α-TCP have low fracture toughness compared to natural bone, so reinforcements such as wollastonite whiskers are developed so that they can be used in places with greater overload. This study aimed to evaluate the biocompatibility and bone neoformation of α-TCP plus 10% wollastonite whiskers, in vivo. To obtain the cement, α-TCP powders with or without 10% wollastonite whiskers were added to an aqueous solution containing 2.5% by weight of Na2HPO4 (anhydrous bibasic sodium phosphate). The biomaterial then became a paste, which was molded into the critical 5 mm defect made in the parietal bone of Wistar rats. Ten rats were divided into two groups. The animals from each group were euthanized within 30 days. Calvaries were removed and subjected to histological processing with Eosin and Hematoxylin. The implementation of the whisker biomaterial revealed the formation of intensely vascularized connective tissue in the implemented region; however, animals with the biomaterial α-TCP showed the formation of this tissue around the implemented region. On the other hand, intense bone resorption was observed only in the animals with Wollastonite Whiskers, but new bone formation in both groups. The biomaterial evaluated was shown to be non-cytotoxic, resorbable, and capable of inducing bone neoformation; however, more studies should be carried out to assess the application of this biomaterial in bone injuries.

Abstract: The present study investigated the phase composition, the structural, morphological, and bioactivity properties of silicon- and carbonate-doped biomimetic hydroxyapatite synthesized by precipitation from aqueous solutions in the presence of different amounts of citrate ions. The X-ray diffraction and Fourier transform infrared spectroscopy analyses confirmed that all the samples exhibited single-phase. Base on the results of the morphological study, all the obtained samples consisted of porous agglomerated particles made up of tiny crystallites in the nanometer range. The change in structural order, as well as the decrease in particle size and degree of crystallinity result from the presence of citrate ions were revealed by X-ray diffraction, dynamic light scattering, and scanning electron microscopy analyses. Bioactivity properties of samples were studied by analyzing their bioresorbability in physiological saline (ω (NaCl) = 0.9%) and evaluating their solubility in SBF solution after a certain period of soaking time. The amount of the released Ca²⁺ ions was found to increase with the increasing concentration of citrate ions introduced in the synthesis process. The better solubility of material with the presence of citrate ions was beneficial in the growth of apatite on its surface that made produced material more biocompatible.

Abstract: Biphasic Calcium Phosphate (BCP) is a ceramic material that consisting of two phases which is Hydroxyapatite (HA) and β-Tricalcium Phosphate (β-TCP). In this work, BCP and Mg-BCP (Mg Doped) was synthesized using aqueous precipitation method at standard room temperature and pressure. The synthesized powder was pressed into pellet and sintered at three consecutive temperatures of 800 °C, 900 °C, and 1000 °C. The sintered pellet was characterized using XRD to obtained the quantification analysis on phases presence and to study the crystal orientation of HA and β-TCP before and after Mg doping was introduced. FTIR was used to determine chemical constituents of synthesized powders. Diameter shrinkage analysis was performed to study the effect of temperatures on the densification of the pellet body and SEM was used to observed the morphology of each pellet. Based on the XRD result, the Mg doping is affecting the stability of the phases presence and the crystal lattice creating a distortion due to the substitution of smaller Mg ion. Analysis on the SEM morphology have shown that Mg doped BCP resulting a dense structure with less formation of porosity, necking was formed clearly at temperatures of 900 °C to 1000 °C.

Abstract: Osteosarcoma, as the most frequent bone tumor cases, can be found in the pelvis bone. Within the pelvis, the ilium is the most common location for osteosarcoma, followed by the acetabulum and then the ischium. Surgery of pelvis is difficult and the reconstruction is complicated mainly due to the geometry complexity and also the weight support function of the pelvis. Endoprosthesis of the ilium is therefore designed to increase the quality of life of the patient. In this study, the iliac implant is designed based on the natural geometry of the ilium, and the size is modified to fit the morphometry of the Eastern Asian. A finite element method (FEM) is proposed as a basic study in material selection. Titanium and its alloy (Ti-6Al-4V) are studied as the potential candidate for the proposed implant while the finite analysis of the bone was also included. As a preliminary study, in this FEM, only the static load is given, each material is assumed to be isotropic and the contacts were considered bonded. FEM in this study is expected to give a better understanding of the stress distribution, and to optimize the selection of materials.

Abstract: A typical adhesive bandage comprises of four main parts; the backing is often made of plastic; the adhesive sheet is usually plastic; the adhesive is commonly acrylate; the absorbent pad is often made of cotton. This adhesive bandages are made from starch based adhesive and natural paper, which have no plastic components. A starch-based adhesive bandages are tested on 100 volunteers and the result shows good performances with high confident of safety and efficacy. The raw materials and preparation methods are low cost, easily reproducible and eco-friendly, according to the international standards of medical devices regulation.

Abstract: The surface wettability of biomaterials influences on osteoblast behavior and bone formation. In this research, the variation of wettability of nacre by heat treatments was examined. Plates of the nacre were fabricated from shells of the Akoya pearl oyster. The specimens were heated at 100, 200, 300, 400, 500, and 600 °C. Characterizations of the specimens during and after heat treatments were carried out using scanning electron microscopy, X-ray diffractometry, and thermogravimetry-differential thermal analysis. The water contact angle (WCA) of the specimen was measured to evaluate wettability. The color of nacre changed from iridescent color to brownish weak-iridescence by the heating at and over 300 °C. The nacre heated at and over 300 °C became brittle because organic substances in nacre, which acts as the glue between the aragonite platelets were evaporated by the heating. The WCA of the specimen was decreased with increasing heating temperature, which should be related to the decrease in the number of organic substances in nacre by the heating.

Abstract: Ti alloys have been intensely used for human implants due to its excellent characteristics, like bio-inertness, low density, and corrosion resistance. However, some alloying elements were found to be toxic for the human body, which restricts the use of some alloys. Furthermore, there are two additional and essential aspects to be considered. The first relates to the young modulus that, despite being lower than other alloys commonly used for this purpose, it is still far over from the human bone modulus. Such high modulus can result in the stress shield phenomena and the consequent implant losing. The second aspect relates to the fact that bio-inertness does not guarantee a complete tissue integration to the implant and, consequently, the expected implant performance. In this context, new low modulus b-Ti alloys containing nontoxic elements have been developed in recent years, and several surface modification processes have been proposed to promote better implant/tissue integration.In the present work, the new b-type Ti-Mo-Zr-Fe alloy has been submitted to a plasma enhanced chemical vapor deposition (PECVD) process in order to form a superficial titanium nitride layer, aiming to produce a satisfactory substrate for the tissue cells growing. In a first step, microstructural characterization and corrosion performance of the modified alloy surface has been evaluated by Electrochemical Impedance Spectrometry and Potentiodynamic testing, and the results compared to the unmodified alloy. It was found that during the plasma nitriding process, that runs at 550°C for 1h, the metastable b microstructure is partially converted into a’ and possibly a” phases, which can impact the young modulus. The 500nm thick TiN layer formed over the alloy surface improved the corrosion behavior of the alloy. These results encourage the continuity of the research, with the future in vitro bio-activity testing of the nitrided surface.