Igor Hut

Polymeric Biomaterials Based on Polylactide, Chitosan and Hydrogels in Medicine

Polymeric biomaterials represent large and very adaptable class of biomaterials, which makes them very suitable for diversity of biomedical applications. Polymers can be synthesized to have a variety of structures and suitable chemical, physical, biomimetic and surface properties. An overabundance of polymeric biomaterials with different compositions and physicochemical properties have already been developed and investigated; however, there are still many active studies about these materials. This chapter ensures a structural review of biodegradable polymers and discusses their physicochemical characteristics, structure property, applications and limitations in medicine. It is the authors’ intent to provide an insight over the available synthetic and natural polymer classes. Some types of polymer materials are less discussed than the other more relevant. A biocompatible, degradable polymer, polylactic acid is very popular so called green ‘eco-friendly’ material with a most promising development prospect. Besides biocompatibility and biodegradability, natural polymer, chitosan, possess outstanding properties. Hydrogels are super absorbent polymeric materials with one of the main role in health care. For these biopolymers, reviews are referenced to present guidance for further reading.

Nanomaterials for Sustainable Energy Production and Storage: Present Day Applications and Possible Developments

Currently used technologies in energy industry are oftentimes potentially harmful for the environment and/or not sustainable in the long run (e.g. fossil and mineral based fuels, nuclear energy). Therefore the oncoming energy crisis must be solved by developing new sustainable energy supply that has lower or, preferably, negligible impact on the environment. Any new sustainable energy solutions will have to envelope three important sets of technologies: production, storage and transportation. Additionally, in order to determine whether these solutions are truly sustainable, adequate life cycle assessment methodology (LCA) needs to be developed and properly applied. This article gives a general survey of state of the art and current research trends in application of nanostructured materials for sustainable energy production, storage and transportation, as well as review of LCA methodology implemented in this domain. A special attention is given to already existent applications and possible future developments of nanotechnology for solar energy production, hydrogen economy, batteries and electrical energy transmission.

CHARACTERIZATION OF NANOMATERIAL-BASED CONTACT LENSES BY ATOMIC FORCE MICROSCOPY

In this paper the comparative studies were conducted of the surface areas of nanophotonic contact lens and contact lens made from base material, measured by Nanoprobe Atomic Force Microscope. Nanoprobe atomic force microscopy (AFM) provides information on the size structure on nano scale level, the form of recorded structures (cavities), their distribution of the surface, and the total roughness of the scanned area. The atomic force microscope used in this study is a SPM-5200 of JEOL, Japan. AFM consists of a cantilever with a sharp tip (probe) at its end that is used to scan the specimen surface. Images of the specimen surface are created by measuring the deflection of the cantilever. The cantilever used in this study is produced by MikroMasch (Estonia) by trade name NCS18/Co-Cr. This AFM probe is silicon etched probe tip that has conical shape. It is coated with Co and Cr layers. Images of surface topography were obtained for each type of contact lenses. The base material of contact lens was made from PMMA and the nanophotonic contact lens was made of fullerene doped PMMA. Fullerenes were used because of their good transitive characteristics in ultraviolet, visible and near infrared light spectrums. Measurements were done at room temperature. Results of topography for both materials are presented and compared.

Nanomaterials for Skin Care

There are a lot of cosmetic products on the market based on nanotechnology. Those products contain nanomaterials since they have many advantages such as improved delivery of active ingredients, stability and photostability of potentially unstable cosmetic ingredients, increased efficacy and tolerance of the skin for various UV filters. Nanomaterials contribute to easiness of application and aesthetic appearance of final products. Although they offer many possibilities, their use demands caution. Nanoparticles have a large surface to volume ratio leading to their reactivity and alteration in biological activity compared to the parent bulk materials. The shape and size of the particles are the cause if their toxic effects, rather than their chemical properties. There are various nanosystems currently in use, in pharmaceutical and cosmetic industry, and many new ones, waiting to be applied. In this article we are going to introduce those who find an application in personal care products such as: liposomes, niosomes, transfersomes, nanoemulsions, solid lipid nanoparticles, polymeric systems, nanocrystals, fullerenes and finally metal oxide nanoparticles.

Short History of Biomaterials Used in Hip Arthroplasty and Their Modern Evolution

The hip joint is one of the largest joints in the body and is a major weight-bearing joint. The function of the hip is to withstand body weight during standing and walking; during single leg stance the hip joint must carry a load three times greater the body weight. However, Joint degeneration is the final phase of the joint cartilage destruction, leading to severe pain, loss of mobility, and sometimes even angular deformity of the limbs. The primary reasons for a large number of total hip replacements are osteoarthritis and osteoporosis of the femoral neck, which often leads to hip fractures. One of the most successful techniques to restore function of a degenerated joint is the total joint replacement. In this surgical procedure, diseased cartilage and parts of the bone are removed and replaced with an appropriate joint prosthesis. Several types of materials and techniques have been developed for this purpose: glass, polymer, metal alloy, ceramics, etc. Earliest prosthesis designs and biomaterials that have been developed to treat osteoarthritic hip degenerated joint surfaces were for the most part empirical and unsuccessful. Joint replacement heralded a revolution after the materials and replacement procedures developed by Sir John Charnley. A modern total hip prosthesis consists of a femoral and acetabular component, where the femoral head is made of cobalt-chrome alloy, alumina or zirconium, and the stem component is now usually made of Ti- or Co-Cr-based alloy. The search for improved designs and new hip implant biomaterials with better biocompatibility and more desirable mechanical properties is still underway.

Nanoscale Material Characterization under the Influence of Aggressive Agents by Magnetic Force Microscopy and Opto-Magnetic Spectroscopy

Magnetic Force Microscopy (MFM) and Opto-Magnetic Spectroscopy (OMS) were used to characterize HTCV stainless steel and aluminum. Both materials were immersed in 1.0M HCl and 1.0M CH3COOH solutions for two hours. From the OMS method it was discovered that treated materials showed differences in peak wavelengths. Topographical and magnetic features for steel plate samples showed better resistance to an aggressive medium compared to aluminum. The results and analysis of these investigations are compared and presented in this paper.