The role of magnetic field in the biopharmaceutical production: Current perspectives

Technological limitations in obtaining and using cellulose biocomposites

Among the many possible types of polymer composite materials, the most important are nanocomposites and biocomposites, which have received tremendous attention in recent years due to their unique properties. The fundamental benefits of using biocomposites as alternative materials to “petroleum-based” products are certainly shaping current development trends and setting directions for future research and applications of polymer composites. A dynamic growth of the production and sale of biocomposites is observed in the global market, which results not only from the growing interest and demand for this type of materials, but also due to the fact that for the developed and modified, thus improved materials, the area of their application is constantly expanding. Already today, polymer composites with plant raw materials are used in various sectors of the economy. In particular, this concerns the automotive and construction industries, as well as widely understood packaging. Bacterial cellulose, for example, also known as bionanocellulose, as a natural polymer with specific and unique properties, has been used extensively,primarily in numerous medical applications. Intensive research is also being carried out into composites with natural fibres composed mainly of organic compounds such as cellulose, hemicellulose and lignin. However, three aspects seem to be associated with the popularisation of biopolymers: performance, processing and cost. This article provides a brief overview of the topic under discussion. What can be the technological limitations considering the methods of obtaining polymer composites with the use of plant filler and the influence on their properties? What properties of cellulose constitute an important issue from the point of view of its applicability in polymers, in the context of compatibility with the polymer matrix and processability? What can be the ways of changing these properties through modifications, which may be crucial from the point of view of the development directions of biopolymers and bioplastics, whose further new applications will be related, among others, to the enhancement of properties? There still seems to be considerable potential to improve the cellulose material composites being produced, as well as to improve the efficiency of their manufacturing. Nevertheless, the material still needs to be well optimized before it can replace conventional materials at the industrial level in the near future. Typically, various studies discuss their comparison in terms of production, properties and highly demanding applications of plant or bacterial nanocellulose. Usually, aspects of each are described separately in the literature. In the present review, several important data are gathered in one place, providing a basis for comparing the types of cellulose described. On the one hand, this comparison aims to demonstrate the advantage of bacterial cellulose over plant cellulose, due to environmental protection and its unique properties. On the other hand, it aims to prepare a more comprehensive point of view that can objectively help in deciding which cellulosic raw material may be more suitable for a particular purpose, bacterial cellulose or plant cellulose.

Biopharmaceutical-Type Chinese Hamster Ovary Cell Cultivation Under Static Magnetic Field Exposure: A Study of Genotoxic Effect

The lack of a sufficient research base is the reason for the ongoing discussion regarding the genotoxic effect of magnetic field (MF) exposure on mammalian cell cultures. Chinese hamster ovary (CHO) suspension-type cells, which are widely used for biopharmaceutical production, are potentially subjected to an increased MF when cultivated in bioreactors equipped with bottom-placed magnetically coupled stirring mechanisms. The main challenge for conducting research in this field remains the availability of a suitable experimental setup that generates an appropriate MF for the raised research question. In the present study, a simple and cost-effective experimental setup was developed that generated a static MF, similar to what has been modeled in large-scale bioreactors and, at the same time, was suitable for experimental cell cultivation in laboratory conditions. The measured maximum magnetic flux density to which the cells were exposed was 0.66 T. To assess the possible genotoxic effect, cells were continuously subcultivated in laboratory petri dishes for a period of 14 days, corresponding to a typical duration of a biopharmaceutical production process in a conventional fed-batch regime. The genotoxic effect was assessed using the cytokinesis-block micronucleus assay with fluorescent staining. Results showed that a 0.66-T static MF exposure had no significant long-term effect on cell viability and chromosomal damage but demonstrated a short-term effect on cell apoptosis. Significant increase in nuclear bud formation was observed. These findings may encourage other researchers in future studies investigating cellular responses to MF exposure and contribute relevant data for comparison.

Evaluating the Effectiveness of Biophysical Methods of Osteogenesis Stimulation: Review

Background. Stimulation of osteogenesis (SO) by biophysical methods has been widely used in practice to accelerate healing or stimulate the healing of fractures with non-unions, since the middle of the XIX century. SO can be carried out by direct current electrostimulation, or indirectly by low-intensity pulsed ultrasound, capacitive electrical coupling stimulation, and pulsed electromagnetic field stimulation. SO simulates natural physiological processes: in the case of electrical stimulation, it changes the electromagnetic potential of damaged cell tissues in a manner similar to normal healing processes, or in the case of low-intensity pulsed ultrasound, it produces weak mechanical effects on the fracture area. SO increases the expression of factors and signaling pathways responsible for tissue regeneration and bone mineralization and ultimately accelerates bone union.The purpose of this review was to present the most up-to-date data from laboratory and clinical studies of the effectiveness of SO.Material and Methods. The results of laboratory studies and the final results of metaanalyses for each of the four SO methods published from 1959 to 2020 in the PubMed, EMBASE, and eLibrary databases are reviewed.Conclusion. The use of SO effectively stimulates the healing of fractures with the correct location of the sensors, compliance with the intensity and time of exposure, as well as the timing of use for certain types of fractures. In case of non-union or delayed union of fractures, spondylodesis, arthrodesis, preference should be given to non-invasive methods of SO. Invasive direct current stimulation can be useful for non-union of long bones, spondylodesis with the risk of developing pseudoarthrosis.

Evaluating the Effectiveness of Biophysical Methods of Osteogenesis Stimulation: Review

Background. Stimulation of osteogenesis (SO) by biophysical methods has been widely used in practice to accelerate healing or stimulate the healing of fractures with non-unions, since the middle of the XIX century. SO can be carried out by direct current electrostimulation, or indirectly by low-intensity pulsed ultrasound, capacitive electrical coupling stimulation, and pulsed electromagnetic field stimulation. SO simulates natural physiological processes: in the case of electrical stimulation, it changes the electromagnetic potential of damaged cell tissues in a manner similar to normal healing processes, or in the case of low-intensity pulsed ultrasound, it produces weak mechanical effects on the fracture area. SO increases the expression of factors and signaling pathways responsible for tissue regeneration and bone mineralization and ultimately accelerates bone union.The purpose of this review was to present the most up-to-date data from laboratory and clinical studies of the effectiveness of SO.Material and Methods. The results of laboratory studies and the final results of metaanalyses for each of the four SO methods published from 1959 to 2020 in the PubMed, EMBASE, and eLibrary databases are reviewed.Conclusion. The use of SO effectively stimulates the healing of fractures with the correct location of the sensors, compliance with the intensity and time of exposure, as well as the timing of use for certain types of fractures. In case of non-union or delayed union of fractures, spondylodesis, arthrodesis, preference should be given to non-invasive methods of SO. Invasive direct current stimulation can be useful for non-union of long bones, spondylodesis with the risk of developing pseudoarthrosis.