Micro‐ and Nanocarriers for Immobilization of Enzymes

Two types of micro‐ and nanocarriers for immobilization of enzymes for biotechnological and biomedical applications are described: magnetic nanoparticles and cross‐linked enzyme aggregates (CLEAs). Nanosized structures with their large surface and smaller size volume ratio, which is dependent on their strong magnetic dipole, give key features that make magnetic nanoparticles useful in many biotechnological and biomedical applications. They are therefore used as carriers to which different active substances can bind. The preparation of the magnetic nanoparticles, possible surface coating methods, and functionalization with different materials are described. Enzyme immobilization methods, such as adsorption, affinity binding, chelation, or metal binding or covalent binding, enable the preparation of efficient and stable enzyme bound to magnetic nanoparticles. Such a product may be used among bioreactor applications for targeted drug delivery in biosensors or bioimaging and magnetic resonance imaging. Preparation of CLEAs, the microsized enzyme structures without a carrier, is described as well. Their main advantage is very simple preparation, where two steps, precipitation of the enzyme and cross‐linking, are joined. A broad spectrum of enzymes for CLEA preparation has been used and many biotechnological reactions are catalyzed. The improvement in CLEA preparation to enhance their stability and operability is also shown

The IMSI procedure improves poor embryo development in the same infertile couples with poor semen quality: A comparative prospective randomized study

<p>Abstract</p> <p>Background</p> <p>Sperm of poor quality can negatively affect embryo development to the blastocyst stage. The aim of this comparative prospective randomized study was to evaluate the role of an intracytoplasmic morphologically selected sperm injection (IMSI) in the same infertile couples included in the programme of intracytoplasmic sperm injection (ICSI) due to their indications of male infertility which had resulted in all arrested embryos following a prolonged 5-day culture in previous ICSI cycles.</p> <p>Methods</p> <p>Couples exhibiting poor semen quality and with all arrested embryos following a prolonged 5-day culture in previous ICSI cycles were divided into two groups: <it>Group 1: IMSI group </it>(n = 20) with IMSI performed in a current attempt and <it>Group 2: ICSI group </it>(n = 37) with a conventional ICSI procedure performed in a current attempt of <it>in vitro </it>fertilization. Fertilization rate, embryo development, implantation, pregnancy and abortion rates were compared between current IMSI and conventional ICSI procedures, and with previous ICSI attempts.</p> <p>Results</p> <p>The <it>IMSI group </it>was characterized by a higher number of blastocysts per cycle than the <it>ICSI group </it>(0.80 vs. 0.65) after a prolonged 5-day embryo culture. There was a significantly lower number of cycles with all arrested embryos and cycles with no embryo transfer in the <it>IMSI group </it>versus the <it>ICSI group </it>(0% vs. 27.0%, p = 0.048). After the transfer of embryos at the blastocyst or morula stage (on luteal day 5) a tendency toward higher implantation and pregnancy rates per cycle was achieved in the <it>IMSI group </it>compared to the <it>ICSI group </it>(17.1% vs. 6.8%; 25.0% vs. 8.1%, respectively), although not statistically significant. After IMSI, all pregnancies achieved by the blastocyst transfer were normally on-going, whereas after ICSI, two of three pregnancies ended in spontaneous abortion. After IMSI, two pregnancies were also achieved by the morula stage embryos, whereas after the conventional ICSI procedure, embryos at the morula stage did not implant.</p> <p>Conclusions</p> <p>The IMSI procedure improved embryo development and the laboratory and clinical outcomes of sperm microinjection in the same infertile couples with male infertility and poor embryo development over the previous ICSI attempts.</p

Efficient Removal of Cr(VI) Ions from Aqueous Solutions Using Arabinogalactan Coated Magnetic Nanoparticles

Heavy metals being the most common pollutants of water and soil pose a risk for the ecosystems due to their non-degradable nature. Especially, chromium (Cr) is widely used in metal plating, pigmentation, printing, textile dyeing, wood preservation and other industries, therefore being a very common pollutant in surface and underground waters. The elimination of such pollutants from wastewater is highly important because of their carcinogenic and toxic nature. Among many methods for the removal of Cr(VI) ions from wastewater, adsorption is the most common and effective physiochemical method, because of its high efficiency, recyclability, cost-effectiveness and simplicity. Polysaccharides have been extensively employed in synthesis of magnetic nanoparticles (MNPs) as coating materials for constructing an adsorptive material, mainly due to their high adsorptive ability and low-cost. They are also environmentally friendly, renewable, biodegradable, biocompatible and can easily be modified. Arabinogalactan (AG) is a polysaccharide, that has high adsorption capacity for Cr(VI) ions. AG modified magnetic nanoparticles (AG-MNPs) were prepared by co-precipitation method using ferric and ferrous ions and later used as the adsorptive material for efficient Cr(VI) removal. The optimum conditions for Cr(VI) ions adsorption were found to be at pH 4, with contact period of only 30 min at 200 rpm, resulting in 92.9% adsorption efficiency and 99.6% maximum adsorption efficiency after 120 min at 200 rpm, using Cr(VI) ions at concentration of 0.5, 1.0 and 5.0 mg/L

Toxicity of Magnetic Chitosan Micro and Nanoparticles as Carriers for Biologically Active Substances

Abstract Nanoparticles of inorganic magnetic core surrounded by layers of functional coatings are potential representatives of nanostructures for immobilization of bio-substances. Magnetic nanoparticles (MNPs) are often bound in aggregates due to a strong magnetic dipole, which has a lot of advantages, such as large surface area for binding biologically active substances. Chitosan is a polysaccharide polymer that is non-toxic, hydrophilic, biocompatible and has hydroxy and amino groups in its structure. Because of these chemical and biological properties it is a desirable bio-product for immobilization of enzymes and for binding of other biologically active substances. Magnetic micro and nanoparticles were synthesized with chitosan by three different methods; microemulsion process, suspension cross-linking technique and covalent binding of chitosan. Toxic effect of the prepared magnetic particles was determined as well and was examined on five different bacterial cultures; Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis and Klebsiella pneumoniae. At concentrations of 10-30 mg of magnetic particles per 0.5 McFarland Standard solution of E. coli and per 400 CFU of S. aureus, P. aeruginosa, E. faecalis in K. pneumonia, no inhibition on the chosen bacterial cultures was detected

Prevention and control of infections in ambulance vehicles

Teoretična izhodišča: Problematika okužb, povezanih z zdravstvom, postaja vedno večji in resen problem sodobne zdravstvene nege, saj povzročajo resne posledice za paciente, svojce, zdravstveno osebje in za ves zdravstveni sistem. Bolnišnične okužbe so najpogostejši zaplet zdravljenja v bolnišnici. Namen: Namen diplomskega dela je predstaviti prenos in širjenje večkratno odpornih bakterij in ukrepe za preprečevanje širjenja le teh v reševalnem vozilu. Z raziskavo želimo ugotoviti ali zdravstveni delavci – reševalci upoštevajo in izvajajo ukrepe za preprečevanje okužb. Metodologija rziskovanja: V diplomskem delu smo uporabili deskriptivno metodo dela. V raziskavi je sodelovalo 60 reševalcev. Podatki so bili zbrani s tehniko anketiranja, dobljene kvantitativne podatke, ki smo jih analizirali, smo prikazali v deležih. Rezultati: Ugotovili smo, da dobra polovica (63,33 %) anketiranih reševalcev pozna ukrepe za preprečevanje okužb. Svoje znanje iz tega področja ocenjujejo dobro, kljub temu pa bi se bili pripravljeni še dodatno izobraževati. Prav tako smo ugotovili, da med dvema reševalnima službama v Sloveniji ni večjih razlik v izvajanju ukrepov za preprečevanje OPZ. Sklep: Okužb povezanih z zdravstvom ne bomo mogli nikoli popolnoma preprečiti, zato je le-te toliko bolj pomembno obvladovati. Vsak zdravstveni delavec je dolžan upoštevati ukrepe in opravljati svojo dejavnost s ciljem preprečevanja OPZ, ter se na tem področju izobraževati.Theoretical Background: Healthcare-associated infections (HAIs) pose a serious problem of modern healthcare, affecting the entire healthcare system, mainly patients, their relatives, and medical personnel. HAIs are the most common risk factor for secondary medical problems and complications in hospitals. Objectives: We introduce a literature review of modes of transmission of multidrug resistant bacteria in healthcare settings and guidelines, recommendations, and regulations for infection prevention and control in ambulance vehicles. We also investigate the extent to which ambulance personnel of emergency medical services act in accordance with relevant national legislation on prevention and control of HAIs in Slovenia. Research Design and Methods: We employed quantitative descriptive research design. The study was conducted on a sample of 60 ambulance paramedics from two emergency departments in Slovenia. The data were collected by means of a questionnaire, quantified, and presented in a percent format. Results: More than half (63,33 %) of participants were familiar with the policies and procedures for infection prevention and control, assessed their knowledge and skills as adequate and were compliant to undergo continuous education. On comparison, each emergency department did not show essential variation for the policies and procedures for infection prevention and control. Conclusion: Healthcare-associated infections are impossible to completely prevent, which calls for taking restrictive measures to control the spread of infections. Our results further suggest the need for improved compliance with the infection prevention and control measures, including continuous education and training, among ambulance paramedics to prevent or reduce HAIs in pre-hospital care in Slovenia

Multifunctional iron oxide nanoparticles as promising magnetic biomaterials in drug elivery

A wide range of applications using functionalized magnetic nanoparticles (MNPs) in biomedical applications, such as in biomedicine as well as in biotechnology, have been extensively expanding over the last years. Their potential is tremendous in delivery and targeting systems due to their advantages in biosubstance binding. By applying magnetic materials-based biomaterials to different organic polymers, highly advanced multifunctional bio-composites with high specificity, efficiency, and optimal bioavailability are designed and implemented in various bio-applications. In modern drug delivery, the importance of a successful therapy depends on the proper targeting of loaded bioactive components to specific sites in the body. MNPs are nanocarrier-based systems that are magnetically guided to specific regions using an external magnetic field. Therefore, MNPs are an excellent tool for different biomedical applications, in the form of imaging agents, sensors, drug delivery targets/vehicles, and diagnostic tools in managing disease therapy. A great contribution was made to improve engineering skills in surgical diagnosis, therapy, and treatment, while the advantages and applicability of MNPs have opened up a large scope of studies. This review highlights MNPs and their synthesis strategies, followed by surface functionalization techniques, which makes them promising magnetic biomaterials in biomedicine, with special emphasis on drug delivery. Mechanism of the delivery system with key factors affecting the drug delivery efficiency using MNPs are discussed, considering their toxicity and limitations as well