The morphology of the prepared scaffolds is presented in Fig. 2. It can be observed that all the prepared scaffolds have wide range of interconnected pores including macro, micro and nanopores, as was also confirmed by a mercury porosimeter. By increasing the MB concentration, the pore size in the scaffolds also increased. The average pore size of the scaffolds fabricated was increased from 150 ± 5 µm to 170 ± 24 µm by increasing the concentration of MB from 0 mass-% to 66.5 mass-%. The wide range of pores sizes for all the scaffolds fabricated with different MB concentration indicated that pores in all the scaffolds were interconnected and seeded cells would be proliferated throughout the 3D structure of the scaffold. Thepore size was found to be in the range of 100–200 µm, suitable for tissue engineering applications [18]. Pores are essential for the migration and proliferation of the cells, nutrient supply and vascularization [19]. The surface of the chitosan control scaffold was found to be smooth compared to the Ch/MB composite scaffold. This may be due to the incorporation of MB that significantly increases the surface area of the scaffolds, further enhancing the bioactivity of the scaffolds [20, 21]. The porosity percentage for the prepared scaffolds was determined by MIP and liquid displacement methods, and there was no
significant difference between the two methods, as demonstrated in Table 1.
3.2 Mechanical properties
The mechanical behaviour of the prepared scaffolds was characterized by determining the fracture toughness K. Ch alone exhibits low fracture toughness, as shown in Fig. 3. In the Ch/MB scaffolds a marked change could be observed: as the amount of glass increased the fracture toughness increased. Table ...
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...nal gelatin/montmorillonite-chitosan scaffolds for tissue engineering. React. Funct. Polymer. 67 (2007) 780–788
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Makadia HK. & Siegel SJ., 2011. Poly Lactic-co-Glycolic Acid (PLGA) as Biodegradable Controlled Drug Delivery Carrier. Polymers, 3, 1377-1397
The endothermic melting temperature for Ptx, blank S-SEDDS, physical mixture of Ptx/blank S-SEDDS, and Ptx-loaded S-SEDDS was determined by DSC 2920. Samples were scanned from 30 to 250 °C at a rate of 10 °C /min. In all the cases, an empty pan was used as the reference. XRD patterns of Ptx, blank S-SEDDS, physical mixture of Ptx/blank S-SEDDS and Ptx-loaded S-SEDDS were recorded using an X'Pert PRO Multipurpose X-Ray diffractometer equipped with CuKα radiation (40 kV, 20 mA). The 2θ scanning range was varied from 2° to 50°.
... The advanced technology of surface modification in the biomedical sector have the ability to offer not an improvement in the tribological properties only but also to improve the clinical requirements prior and post implantation. Such properties includes cell growth and antibacterial effect.
Ketoprofen proliposome formulations using pearlitol SD 200 and different ratios of HSPC and cholesterol were prepared. HSPC (a high phase transition temperature lipid) and cholesterol (for structural rigidity) were selected because of their lower risk of oxidation and improved stability of liposomes respectively. However any variation in the composition of HSPC and cholesterol results in the deformation of vesicle, which leads to drug leakage and fusion of vesicle with gastrointestinal epithelium (32). To conquer the lipid to cholesterol composition in developing stable proliposomes varying ratios of HSPC to cholesterol (total lipid mixture of 250 µM) were investigated.
Some ceramics are used in orthopaedic applications such as bone repair, bone augmentation and joint replacement but their use in this field is not as extensive or widespread as metals and polymers because ceramics have poor fracture toughness. This severely limits the use of ceramics in load bearing applications (Davis, 2003).
Laird DF, Mucalo MR, Dias GJ. Vacuum‐assisted infiltration of chitosan or polycaprolactone as a structural reinforcement for sintered cancellous bovine bone graft. Journal of Biomedical Materials Research Part A. 2012;100(10):2581-92.
In this case study, our concern goes for the chitosan nanoparticles; firstly nanoparticles are able to adsorb and/or encapsulate a drug, thus protecting it against chemical and enzymatic degradation. Furthermore the encapsulated drug may be prevented from crystallization, thus forming a solid solution. Depending on drug solubility in the carrier, a drug load varying from only a few percent up to 50%] Secondly, chitosan is ...
Regardless of chitosan's miraculous overview, it is a very simple substance which has been around for ages. It is taken from chitin, a polysaccharide found in the exoskeletons of crustaceans. It is processed by removing the shells from shellfish such as shrimp, lobster, and crabs. The shells are then ground into a pulverous powder. This powder is then deacetylated, or basically stripped of specific chemical groups which allows the compound to thus actively "soak up fats." Or so this is what the producers claim. It has been used in the past in the process of detoxifying water. It was simply spread over the surface of water, where it would immediately absorb any toxic substances such as greases, oils, or dangerous heavy metals. The process is so complete that a scum forms over the surface of water and is then easily removed. For this reason, chitosan is extremely popular all over the world in water purification plants. The present form of chitosan has just been introduced recently as a
These kinds of polymers have both some advantages and disadvantages. Although they are bioactive and biodegradable and provide high comppressive strength, Degradation of such polymers leads to undesired tissue response due to producing acid formation in degradation process. Metallic scaffolds are another method for bone repair and regenaration. They provide high compressive strength and enormous permanent strength. Metallic scaffolds are mainly made of titanium and talium metals. The main disadvantages of metallic scaffolds are not biodegradable and also discharge metal ions. Recent studies in metallic scaffolds mainly focus on biodegradable materials which can be used improve bioactivity of metals such as titanium.
As technology and medicine evolves with rapid pace and patients demand to be treated with the best technology available, while society and health systems are concerned about cost-effectiveness and safety of every procedure in use, there is an urgent need to take advantage of every technology available and make research to broaden our knowledge on nanotechnology and focus on its applications on plastic and reconstructive
... the usage of bioresorbable scaffold involves by selecting certain phenotype of cell and implants it on permeable substance before being implanted to the pulmonary position. The scaffold is presume to degenerate as the cells grow. The last approach involves constructing a mold for leaflets similar to the aortic shape using the collagen constructs (Vesely 2005).
The chitosan nanoparticles used widely as a drug delivery systems last few years. In the present study the Echis carinataus snake venom loaded chitosan nanoparticles were prepared based on ionic gelation of tripolyphosphate and chitosan.. The nanoparticles physicochemical characteristics , stability and biological activity of encapsulated venom were studied . The particles were spherical in shape and the tripolyphosphoric groups of TPP were linked to the ammonium groups of chitosan. Optimum particle size of chitosan and venom loaded nanoparticles were 89 and 116 nm, respectively. Optimum loading capacity and loading efficiency obtained by 500 µg/ml concentration of venom . The biological activity of venom remained intact during nanparticulation and showed no considerable reduction in stability analysis. Our results suggested that Chitosan nanoparticles, which prepared in this work possibly, could be used as an alternative for traditional adjuvants.
Up to present date there are many polymer hosts [1] have been discovered and some examples are
Nano materials have gained great attention with their high surface area and great reactivity. Nano scale synthesis is achieved by two ways: a top down approach (take a larger particles and scale them down), a bottom up (normally chemical synthesis). Because of the abundance of cellulose, a top down approach was selected, although; bottom-up approaches yield a more desirable product with the least amount of defects. The microcrystalline cellulose (Iα, Iβ) is then digested with sulfuric acid this specifically targets the amorphous regions breaking the polymer chain into oligomers on to the nano scale [5,8]. Depending on the concentration of acid will either yield cellulose nano fibrils (CNF’s) or, cellulose nano crystals (CNC’s). CNF’s though still on the micro scale in length are defined as their size in diameter of which ranges from 4-7nm in width [8,14]. Lyophilization aides in the self-assembly behavior as the cellulose begins to align chirally. There are four chiral carbons on each monomer unit of the nanocellulose (2,3,4,5) [1718], which align with chiral carbons from adjacent nanocellulose polymers. Due to the chiral, pneumatic alignment of the nanocellulose during sublimation, a uniform dispersion of cellulose is obtained throughout the polymer composites