Magnetic techniques for the isolation and purification of proteins and peptides

Isolation and separation of specific molecules is used in almost all areas of biosciences and biotechnology. Diverse procedures can be used to achieve this goal. Recently, increased attention has been paid to the development and application of magnetic separation techniques, which employ small magnetic particles. The purpose of this review paper is to summarize various methodologies, strategies and materials which can be used for the isolation and purification of target proteins and peptides with the help of magnetic field. An extensive list of realised purification procedures documents the efficiency of magnetic separation techniques

Magnetic fluid modified peanut husks as an adsorbent for organic dyes removal

AbstractMagnetically responsive nanocomposite materials, prepared by modification of diamagnetic materials by magnetic fluids (ferrofluids), have already found many important applications in various areas of biosciences, medicine, biotechnology, environmental technology etc. Ferrofluid modified biological waste (peanut husks) has been successfully used for the separation and removal of water soluble organic dyes and thus this low cost adsorbent could be potentially used for waste water treatment

Parents’ experiences of stepping back in the decision-making process during transition in the cleft pathway

Background Cleft lip and/or palate (CL/P) is the most common congenital craniofacial condition that can cause physical health complications, psychological difficulties and challenges in social interactions. Parents of children with CL/P are also affected as they face challenges of demanding care needs and long-term treatment. It is important to understand parents’ experiences and their needs to support them when caring for their children. Method First, a systematic review was conducted to appraise and synthesise evidence of parental attachment in the early years of lives of children with CL/P and subsequent parental. Second, an empirical study explored parental experiences of a decision-making process about an elective, orthognathic surgery when the responsibility of the decision moves from parents to the young person affected. Results The systematic review found that after some changes during the first year, there are no differences in attachment between mothers of children with and without cleft at five years. Findings on parenting were mixed but the majority highlighted either no differences in comparison to parents of healthy children or fostering autonomy despite worries about children’s health and physical safety. The empirical study identified three main themes, ‘”Our” journey’, ‘Stepping back’ and ‘Helping with the bigger picture’, reflecting the changing role in responsibility for decision-making. Conclusions The thesis focuses on two key time periods identified in literature, the start and the end of the cleft journey, to better understand parental needs. Parents develop attachment to their child while adjusting to their needs and undergoing initial surgeries during the first year. Parents’ experiences of stepping back in the decision-making process during transition in the cleft pathway Another crucial period is the transition of decision-making regarding the orthognathic surgery when parents are expected to hand over responsibility to their adolescent child. The thesis highlights complexities and potential key factors impacting on parental experience, i.e., the age of the young people and parenting styles

Magnetically modified Posidonia oceanica biomass as an adsorbent for organic dyes removal

Magnetically modified Posidonia oceanica sea grass dead biomass was employed as an adsorbent of organic dyes. The adsorption of seven water-soluble organic dyes was characterized using Langmuir adsorption model. The highest calculated maximum adsorption capacity was found for Bismarck brown Y (233.5 mg g-1), while the lowest capacity value was obtained for safranin O (88.1 mg g-1). The adsorption processes followed the pseudo-second-order kinetic model and the thermodynamic studies indicated spontaneous and endothermic adsorption

Composite scaffolds for cartilage tissue engineering based on natural polymers of bacterial origin, thermoplastic poly(3-hydroxybutyrate) and micro-fibrillated bacterial cellulose

Cartilage tissue engineering is an emerging therapeutic strategy that aims to regenerate damaged cartilage caused by disease, trauma, ageing or developmental disorder. Since cartilage lacks regenerative capabilities, it is essential to develop approaches that deliver the appropriate cells, biomaterials and signalling factors to the defect site. Materials and fabrication technologies are therefore critically important for cartilage tissue engineering in designing temporary, artificial extracellular matrices (scaffolds), which support 3D cartilage formation. Hence, this work aimed to investigate the use of poly(3-hydroxybutyrate)/microfibrillated bacterial cellulose (P(3HB)/MFC) composites as 3D-scaffolds for potential application in cartilage tissue engineering. The compression moulding/particulate leaching technique employed in the study resulted in good dispersion and a strong adhesion between the MFC and the P(3HB) matrix. Furthermore, the composite scaffold produced displayed better mechanical properties than the neat P(3HB) scaffold. On addition of 10, 20, 30 and 40 wt% MFC to the P(3HB) matrix, the compressive modulus was found to have increased by 35%, 37%, 64% and 124%, while the compression yield strength increased by 95%, 97%, 98% and 102% respectively with respect to neat P(3HB). Both cell attachment and proliferation were found to be optimal on the polymer-based 3D composite scaffolds produced, indicating a non-toxic and highly compatible surface for the adhesion and proliferation of mouse chondrogenic ATDC5 cells. The large pores sizes (60 - 83 µm) in the 3D scaffold allowed infiltration and migration of ATDC5 cells deep into the porous network of the scaffold material. Overall this work confirmed the potential of P(3HB)/MFC composites as novel materials in cartilage tissue engineering

P(3HB) Based Magnetic Nanocomposites: Smart Materials for Bone Tissue Engineering

The objective of this work was to investigate the potential application of Poly(3-hydroxybutyrate)/magnetic nanoparticles, P(3HB)/MNP, and Poly(3-hydroxybutyrate)/ferrofluid (P(3HB)/FF) nanocomposites as a smart material for bone tissue repair. The composite films, produced using conventional solvent casting technique, exhibited a good uniform dispersion of magnetic nanoparticles and ferrofluid and their aggregates within the P(3HB) matrix. The result of the static test performed on the samples showed that there was a 277% and 327% increase in Young's modulus of the composite due to the incorporation of MNP and ferrofluid, respectively. The storage modulus of the P(3HB)MNP and P(3HB)/FF was found to have increased to 186% and 103%, respectively, when compared to neat P(3HB). The introduction of MNP and ferrofluid positively increased the crystallinity of the composite scaffolds which has been suggested to be useful in bone regeneration. The total amount of protein absorbed by the P(3HB)/MNP and P(3HB)/FF composite scaffolds also increased by 91% and 83%, respectively, with respect to neat P(3HB). Cell attachment and proliferation were found to be optimal on the P(HB)/MNP and P(3HB)/FF composites compared to the tissue culture plate (TCP) and neat P(3HB), indicating a highly compatible surface for the adhesion and proliferation of the MG-63 cells. Overall, this work confirmed the potential of using P(3HB)/MNP and P(3HB)/FF composite scaffolds in bone tissue engineering

New magnetically responsive yeast-based biosorbent for the efficient removal of water-soluble dyes

Fodder yeast (Kluyveromyces fragilis) cells were magnetically modified by a contact with thewater-based magnetic fluid in order to prepare a new type of magnetically responsive biocomposite material. This procedure enabled a simple separation of modified cells by means of commercially available magnetic separators or strong permanent magnets. It allows using the prepared material as a new inexpensive magnetic affinity adsorbent for the removal of water-soluble dyes. Magnetically modified cells were characterized by means of magnetic and microscopy methods. Both isolated magnetic nanoparticles and aggregates of particles were present on the cell surface. The prepared material displayed a superparamagnetic behavior at room temperature, with a transition to a blocked state at TB 180K for the applied magnetic field H=50Oe. Seven dyes (crystal violet, amido black 10B, congo red, Saturn blue LBRR, Bismarck brown, acridine orange and safranin O) were used to study the adsorption process. The dyes adsorption could be described with the Langmuir isotherm. The maximum adsorption capacities ranged between 29.9 (amido black 10B) and 138.2 (safranin O) mg of dye per g of dried magnetically modified cells

P(3HB) Based Magnetic Nanocomposites: Smart Materials for Bone Tissue Engineering

The objective of this work was to investigate the potential application of Poly(3-hydroxybutyrate)/magnetic nanoparticles, P(3HB)/MNP, and Poly(3-hydroxybutyrate)/ferrofluid (P(3HB)/FF) nanocomposites as a smart material for bone tissue repair. The composite films, produced using conventional solvent casting technique, exhibited a good uniform dispersion of magnetic nanoparticles and ferrofluid and their aggregates within the P(3HB) matrix. The result of the static test performed on the samples showed that there was a 277% and 327% increase in Young’s modulus of the composite due to the incorporation of MNP and ferrofluid, respectively. The storage modulus of the P(3HB)MNP and P(3HB)/FF was found to have increased to 186% and 103%, respectively, when compared to neat P(3HB). The introduction of MNP and ferrofluid positively increased the crystallinity of the composite scaffolds which has been suggested to be useful in bone regeneration. The total amount of protein absorbed by the P(3HB)/MNP and P(3HB)/FF composite scaffolds also increased by 91% and 83%, respectively, with respect to neat P(3HB). Cell attachment and proliferation were found to be optimal on the P(HB)/MNP and P(3HB)/FF composites compared to the tissue culture plate (TCP) and neat P(3HB), indicating a highly compatible surface for the adhesion and proliferation of the MG-63 cells. Overall, this work confirmed the potential of using P(3HB)/MNP and P(3HB)/FF composite scaffolds in bone tissue engineering

Trichomonas vaginalis vast BspA-like gene family: evidence for functional diversity from structural organisation and transcriptomics

<p>Abstract</p> <p>Background</p> <p><it>Trichomonas vaginalis </it>is the most common non-viral human sexually transmitted pathogen and importantly, contributes to facilitating the spread of HIV. Yet very little is known about its surface and secreted proteins mediating interactions with, and permitting the invasion and colonisation of, the host mucosa. Initial annotations of <it>T. vaginalis </it>genome identified a plethora of candidate extracellular proteins.</p> <p>Results</p> <p>Data mining of the <it>T. vaginalis </it>genome identified 911 BspA-like entries (TvBspA) sharing TpLRR-like leucine-rich repeats, which represent the largest gene family encoding potential extracellular proteins for the pathogen. A broad range of microorganisms encoding BspA-like proteins was identified and these are mainly known to live on mucosal surfaces, among these <it>T. vaginalis </it>is endowed with the largest gene family. Over 190 TvBspA proteins with inferred transmembrane domains were characterised by a considerable structural diversity between their TpLRR and other types of repetitive sequences and two subfamilies possessed distinct classic sorting signal motifs for endocytosis. One TvBspA subfamily also shared a glycine-rich protein domain with proteins from <it>Clostridium difficile </it>pathogenic strains and <it>C. difficile </it>phages. Consistent with the hypothesis that TvBspA protein structural diversity implies diverse roles, we demonstrated for several TvBspA genes differential expression at the transcript level in different growth conditions. Identified variants of repetitive segments between several TvBspA paralogues and orthologues from two clinical isolates were also consistent with TpLRR and other repetitive sequences to be functionally important. For one TvBspA protein cell surface expression and antibody responses by both female and male <it>T. vaginalis </it>infected patients were also demonstrated.</p> <p>Conclusions</p> <p>The biased mucosal habitat for microbial species encoding BspA-like proteins, the characterisation of a vast structural diversity for the TvBspA proteins, differential expression of a subset of TvBspA genes and the cellular localisation and immunological data for one TvBspA; all point to the importance of the TvBspA proteins to various aspects of <it>T. vaginalis </it>pathobiology at the host-pathogen interface.</p