Functional characterization of microcrystalline cellulose obtained from the crop residues

Crop residues (CR) are usually burned in the field, which causes air pollution, contributes to global warming, hinders nutrient recycling, and negatively affects soil microbes through overheating and carbon loss. There is growing interest in developing processes for isolation of value added components with application in different industries from CR as feedstock. In this study, different procedures for isolation of microcrystalline cellulose (MCC) from wheat, corn and sunflower CR were evaluated, with further testing of functional characteristics of MCC, which are relevant for tablets production.14th Central European Symposium on Pharmaceutical Technology, 28th - 30th September, Ohrid, N. Macedonia, 202

Mosquitoes in Croatia, transmitting diseases, ways of prevention and control

SažetakZaštita prirode i okoliša danas čini sastavni dio gospodarskog i šireg društvenog razvoja. Podizanjem razine svijesti, proaktivnim razmišljanjem i djelovanjem, možemo računati na 10.održivi razvoj nadolazećih generacija. Ipak, u toj namjeri promjene ekosustava posljedično utječu na brojnost pojedinih vrsta insekata. Komarci su kozmopolitske životinje iz porodice Culicidae. Prenosnici su mnogih patogena koji izazivaju brojne bolesti kod ljudi i životinja: denga groznica, žuta groznica, groznica Zapadnog Nila, tularemija, japanski encefalitis, malarija, zika groznica i dr. Cilj ovoga preglednog rada je sažeto objediniti trenutne znanstvene spoznaje o komarcima, njihovom životnom ciklusu, vrstama prisutnima u Republici Hrvatskoj, načinu prenošenja mikroorganizama, bolestima koje pojedine vrste komaraca na području Hrvatske prenose te prikaz najmodernijih rješenja prevencije i suzbijanja invazivne vektorske vrste komarca Aedes albopictus putem tehnike sterilnih mužjaka (SIT) koja se smatra među ekološki najprihvatljivijom i najrazvijenijom metodom suzbijanja štetočina kukaca.SummaryToday, the protection of nature and the environment is an integral part of economic and general social development. By raising awareness, thinking and acting proactively, we can count on the sustainable development of future generations. Nevertheless, changes in the ecosystem also have an impact on the number of individual insect species. Mosquitoes are cosmopolitan animals belonging to the family Culicidae. They are carriers of many pathogens that cause numerous diseases in humans and animals: Dengue fever, yellow fever, West Nile fever, tularemia, Japanese encephalitis, malaria, Zika fever, etc. The aim of this review is to summarize the current scientific knowledge about mosquitoes, their life cycle, the species present in the Republic of Croatia, the mode of transmission of microorganisms and the diseases transmitted by certain mosquito species in Croatia, and to present the most modern solutions for prevention and control of invasive vector species of mosquito Aedes albopictus using the technique of sterile males (SIT), which is considered one of the most environmentally friendly and developed methods of insect pest control

The Errant Labor of the Humanities: Festschrift Presented to Stipe Grgas

In preparing this Festschrift, we had in mind a specific inflection of the concept of errancy, one that comes from the rich and layered work of the American scholar and philosopher William V. Spanos, who conceived it as a way of rendering the logos and telos of the American project subject to thorough rethinking and redefinition, both in history and at present. By calling attention to the complementarity of the work of the two scholars, Grgas and Spanos, who both hone their critical skills on the theme of the logic of the American project, we do not so much intend to claim a direct influence but rather wish to highlight the confluence, commingling, and inspiration that working in the humanities may engender. This commonality is featured in the work of Spanos and in the work of Grgas as a dedicated and passionate engagement with the practices and possibilities inscribed in the discipline, which also requires the scholar to move beyond the given and inhabit what Spanos calls a meta-level of thinking. Grgas’s work, located at the intersection of several disciplines within the humanities and social sciences (which is reflected in the principal themes of this Festschrift), reveals precisely such a commitment that has in the course of his long, fruitful and versatile career charted out a scholarly position always in the process of becoming, and never quite stabilized and domesticated. Grgas’s academic career has been as diverse as the humanistic disciplinary habitus allows: a provocative and popular lecturer, a researcher of tireless intellectual curiosity, a scholar testing the boundaries of disciplines, an enthusiastic and motivating mentor, a thoughtful and sensitive translator, or, as one of the contribution shows, an unobtrusive poet, Grgas has always displayed a remarkable intellectual energy in every aspect of his engagement with the varied and nowadays often embattled debates in the humanities. However, Grgas’s work as an Americanist, cultural theorist, translator, writer, mentor, and teacher doesn’t merely reflect the exciting, if uncontainable, shifts marking the discipline in the last couple of decades; rather, his intellectual labor has been committed to offering a new way of comprehending this change, its scope, direction, and consequences, so as to create an intense web of connections and interrelations where different disciplines talk to one another, without hastening to provide answers so much as to provoke the right kind of questions. The questioning and questing nature of Grgas’s work has marked his writing from the start, but it has intensified in his later writing as the humanities find themselves facing a whole new set of questions for the new millennium. His sustained effort to bring a new awareness of economic issues to discussions of culture and literature in the recent period has been both timely and critically engaged in its reflection on why this issue is particularly significant at this point in history. The layout of the Festschrift may be said to loosely reflect and acknowledge Grgas’s scholarly interests that have charted out his career in the field of the humanities. (from the Editors’ Preface)In preparing this Festschrift, we had in mind a specific inflection of the concept of errancy, one that comes from the rich and layered work of the American scholar and philosopher William V. Spanos, who conceived it as a way of rendering the logos and telos of the American project subject to thorough rethinking and redefinition, both in history and at present. By calling attention to the complementarity of the work of the two scholars, Grgas and Spanos, who both hone their critical skills on the theme of the logic of the American project, we do not so much intend to claim a direct influence but rather wish to highlight the confluence, commingling, and inspiration that working in the humanities may engender. This commonality is featured in the work of Spanos and in the work of Grgas as a dedicated and passionate engagement with the practices and possibilities inscribed in the discipline, which also requires the scholar to move beyond the given and inhabit what Spanos calls a meta-level of thinking. Grgas’s work, located at the intersection of several disciplines within the humanities and social sciences (which is reflected in the principal themes of this Festschrift), reveals precisely such a commitment that has in the course of his long, fruitful and versatile career charted out a scholarly position always in the process of becoming, and never quite stabilized and domesticated. Grgas’s academic career has been as diverse as the humanistic disciplinary habitus allows: a provocative and popular lecturer, a researcher of tireless intellectual curiosity, a scholar testing the boundaries of disciplines, an enthusiastic and motivating mentor, a thoughtful and sensitive translator, or, as one of the contribution shows, an unobtrusive poet, Grgas has always displayed a remarkable intellectual energy in every aspect of his engagement with the varied and nowadays often embattled debates in the humanities. However, Grgas’s work as an Americanist, cultural theorist, translator, writer, mentor, and teacher doesn’t merely reflect the exciting, if uncontainable, shifts marking the discipline in the last couple of decades; rather, his intellectual labor has been committed to offering a new way of comprehending this change, its scope, direction, and consequences, so as to create an intense web of connections and interrelations where different disciplines talk to one another, without hastening to provide answers so much as to provoke the right kind of questions. The questioning and questing nature of Grgas’s work has marked his writing from the start, but it has intensified in his later writing as the humanities find themselves facing a whole new set of questions for the new millennium. His sustained effort to bring a new awareness of economic issues to discussions of culture and literature in the recent period has been both timely and critically engaged in its reflection on why this issue is particularly significant at this point in history. The layout of the Festschrift may be said to loosely reflect and acknowledge Grgas’s scholarly interests that have charted out his career in the field of the humanities. (from the Editors’ Preface

The Errant Labor of the Humanities: Festschrift Presented to Stipe Grgas

In preparing this Festschrift, we had in mind a specific inflection of the concept of errancy, one that comes from the rich and layered work of the American scholar and philosopher William V. Spanos, who conceived it as a way of rendering the logos and telos of the American project subject to thorough rethinking and redefinition, both in history and at present. By calling attention to the complementarity of the work of the two scholars, Grgas and Spanos, who both hone their critical skills on the theme of the logic of the American project, we do not so much intend to claim a direct influence but rather wish to highlight the confluence, commingling, and inspiration that working in the humanities may engender. This commonality is featured in the work of Spanos and in the work of Grgas as a dedicated and passionate engagement with the practices and possibilities inscribed in the discipline, which also requires the scholar to move beyond the given and inhabit what Spanos calls a meta-level of thinking. Grgas’s work, located at the intersection of several disciplines within the humanities and social sciences (which is reflected in the principal themes of this Festschrift), reveals precisely such a commitment that has in the course of his long, fruitful and versatile career charted out a scholarly position always in the process of becoming, and never quite stabilized and domesticated. Grgas’s academic career has been as diverse as the humanistic disciplinary habitus allows: a provocative and popular lecturer, a researcher of tireless intellectual curiosity, a scholar testing the boundaries of disciplines, an enthusiastic and motivating mentor, a thoughtful and sensitive translator, or, as one of the contribution shows, an unobtrusive poet, Grgas has always displayed a remarkable intellectual energy in every aspect of his engagement with the varied and nowadays often embattled debates in the humanities. However, Grgas’s work as an Americanist, cultural theorist, translator, writer, mentor, and teacher doesn’t merely reflect the exciting, if uncontainable, shifts marking the discipline in the last couple of decades; rather, his intellectual labor has been committed to offering a new way of comprehending this change, its scope, direction, and consequences, so as to create an intense web of connections and interrelations where different disciplines talk to one another, without hastening to provide answers so much as to provoke the right kind of questions. The questioning and questing nature of Grgas’s work has marked his writing from the start, but it has intensified in his later writing as the humanities find themselves facing a whole new set of questions for the new millennium. His sustained effort to bring a new awareness of economic issues to discussions of culture and literature in the recent period has been both timely and critically engaged in its reflection on why this issue is particularly significant at this point in history. The layout of the Festschrift may be said to loosely reflect and acknowledge Grgas’s scholarly interests that have charted out his career in the field of the humanities. (from the Editors’ Preface)In preparing this Festschrift, we had in mind a specific inflection of the concept of errancy, one that comes from the rich and layered work of the American scholar and philosopher William V. Spanos, who conceived it as a way of rendering the logos and telos of the American project subject to thorough rethinking and redefinition, both in history and at present. By calling attention to the complementarity of the work of the two scholars, Grgas and Spanos, who both hone their critical skills on the theme of the logic of the American project, we do not so much intend to claim a direct influence but rather wish to highlight the confluence, commingling, and inspiration that working in the humanities may engender. This commonality is featured in the work of Spanos and in the work of Grgas as a dedicated and passionate engagement with the practices and possibilities inscribed in the discipline, which also requires the scholar to move beyond the given and inhabit what Spanos calls a meta-level of thinking. Grgas’s work, located at the intersection of several disciplines within the humanities and social sciences (which is reflected in the principal themes of this Festschrift), reveals precisely such a commitment that has in the course of his long, fruitful and versatile career charted out a scholarly position always in the process of becoming, and never quite stabilized and domesticated. Grgas’s academic career has been as diverse as the humanistic disciplinary habitus allows: a provocative and popular lecturer, a researcher of tireless intellectual curiosity, a scholar testing the boundaries of disciplines, an enthusiastic and motivating mentor, a thoughtful and sensitive translator, or, as one of the contribution shows, an unobtrusive poet, Grgas has always displayed a remarkable intellectual energy in every aspect of his engagement with the varied and nowadays often embattled debates in the humanities. However, Grgas’s work as an Americanist, cultural theorist, translator, writer, mentor, and teacher doesn’t merely reflect the exciting, if uncontainable, shifts marking the discipline in the last couple of decades; rather, his intellectual labor has been committed to offering a new way of comprehending this change, its scope, direction, and consequences, so as to create an intense web of connections and interrelations where different disciplines talk to one another, without hastening to provide answers so much as to provoke the right kind of questions. The questioning and questing nature of Grgas’s work has marked his writing from the start, but it has intensified in his later writing as the humanities find themselves facing a whole new set of questions for the new millennium. His sustained effort to bring a new awareness of economic issues to discussions of culture and literature in the recent period has been both timely and critically engaged in its reflection on why this issue is particularly significant at this point in history. The layout of the Festschrift may be said to loosely reflect and acknowledge Grgas’s scholarly interests that have charted out his career in the field of the humanities. (from the Editors’ Preface

Use of somatic cell count in the diagnosis of mastitis and its impacts on milk quality

Mastitis je upalna reakcija organizma na infekciju sekretornog dijela mliječne žlijezde. Uzročnici mastitisa dijele se bojanjem po Gramu na Gram-pozitivne i Gramnegativne; prema etiologiji na kontagiozne i uvjetovane uzročnike. Kontagiozni se uzročnici najčešće prenose tijekom mužnje i prouzroče dugotrajne, kronične mastitise, uglavnom subkliničkog tijeka. Za razliku od njih, uvjetovani uzročnici u pravilu izazivaju kratkotrajne infekcije, ali s češćim kliničkim manifestacijama. Inficirane se krave otkrivaju dijagnostikom mastitisa, koja se najčešće provodi neizravnim ili izravnim metodama određivanja broja somatskih stanica i bakteriološkom pretragom mlijeka.Zagrebački mastitis test je brza i jednostavna orijentacijska metoda u procjeni broja somatskih stanica koji se provodi u terenskim uvjetima. Somatske stanice čine epitelne stanice i leukociti. Nalaze se u mlijeku, ali se njihov broj i odnos mijenja ovisno o upalnim promjenama u mliječnoj žlijezdi. Kretanje broja somatskih stanica uglavnom ovisi o pojavi mastitisa, ali i o stadiju laktacije, životnoj dobi životinje, godišnjem dobu, ali i ostalim bolestima mliječne krave. Mlijeko s povećanim brojem somatskih stanica ima promijenjenu kakvoću. Mlijeko sadrži niži udio mliječne masti i laktoze, a povećan je i udio proteina i električna provodljivost zbog povišene koncentracija klora i natrija u mlijeku. Osim toga, mlijeko ima i smanjenu termostabilnost te mu je smanjena sposobnost podsiravanja i formiranja gruša. Takvo mlijeko ima užegli okus i nije pogodno za proizvodnju kondenziranog mlijeka, mlijeka u prahu i steriliziranog mlijeka. Rok trajanja sireva proizvedenih od takvog mlijeka zbog zadržavanja veće količine vode je smanjen. Pravilnim i redovitim provođenjem postupaka dezinfekcije sisa vimena prije i poslije mužnje poboljšava se prinos i kakvoća mlijeka, odnosno smanjuju se troškovi liječenja mastitisa, a povećava se i prihod farme.Mastitis is an inflammatory reaction to an infection of the secretory part of the mammary gland. The causes of mastitis are divided by Gram staining into Gram-positive and Gram-negative, and according to aetiology into contagious and environmental causes. Contagious pathogens are most transmitted during milking, and cause long-lasting, chronic mastitis with a mostly subclinical course. In contrast, environmental pathogens typically cause short-term infections, but with more frequent clinical manifestations. Infected cows are detected by the diagnosis of mastitis, which is most often reached through indirect or direct methods of determining the somatic Cell count and by conducting bacteriological examination of milk. The Zagreb mastitis test is a quick and simple orientation method for estimating the number of somatic cells. Its advantage is that can be performed in field conditions. Somatic cells are made up of epithelial cells and leukocytes. They are normally found in milk, but their number and ratio change depending on inflammatory changes in the mammary gland. The somatic cell count can change depending on the occurrence of mastitis, but also on the stage of lactation, animal age, season and other diseases of the dairy cow. Milk with an increased number of somatic cells has an altered quality compared to the milk of a healthy cow. Milk contains a lower proportion of milk fat and lactose, and an increased proportion of protein. Furthermore, electrical conductivity is increased due to elevated concentrations of chlorine and sodium in milk. It also has reduced thermal stability and a reduced ability to curdle and form lumps. Such milk has a rancid taste and is not suitable for the production of condensed milk, milk powder or sterilized milk. The shelf life of cheeses produced from such milk is reduced due to the retention of a larger amount of water. Proper and regular disinfection of udder teats before and after milking raises the yield and quality of milk, and reduces the cost associated with mastitis treatment, thereby increasing both milk quality and farm revenues

Synthesis and characterization supramolecular hydrogels for the drug delivery and controlled relase

Novi sustavi prijenosa i kontrolirane isporuke lijekova se razvijaju s ciljem poboljšavanja učinkovitosti lijekova i stavljanja pod nadzor postojećih nuspojava. Sintetizirana su dva tripeptidna gelatora 1. organogelator Z-LPhe- L-Phe-L-AlaNH2 i 2. hidrogelator Ac-L-Phe-L-Phe-L-AlaNH2 s ciljem studiranja njihovih potencijala za skladištenje i kontrolirano otpuštanje nesteroidnih antireumatika (NSAR). Nakon dugotrajne oralne uporabe NSAR, poput ibuprofena i acetilsalicilne kiseline mogu se pojaviti ozbiljne nuspojave u gastrointestinalnom traktu. Transdermalna kontrolirana isporuka lijekova pomoću gelova predstavlja alternativnu metodu primjene lijeka pomoću koje se zaobilaze nepoželjni učinci. Za tekuću komponentu organogela odabrano je sojino ulje, a za tekuću komponentu hidrogela vodeni fosfatni pufer. U tripeptidne gelove su ugrađeni ibuprofen i acetilsalicilna kiselina, te se pratilo otpuštanje lijekova ovisno o vremenu u fosfatni pufer pomoću UV-Vis spektroskopije. Nadalje, proučavao se utjecaj pH prihvatnog medija na otpuštanje ibuprofena iz organogela. Otpuštanje je mjereno pomoću dva različita sustava. Kumulativno, uzimanjem uzorka kroz određen vremenski period i određivanjem koncentracije lijeka pomoću UV Vis spektroskopije (u kiveti) ili direktno optičkom sondom. Uspoređivani su rezultati dobiveni različitim metodama mjerenja. Mehanokemijskom reakcijom hidrogelatora i ibuprofena u kugličnom mlinu ispitivao se potencijal hidrogelatora za poboljšanje topljivosti hidrofobnog lijeka u vodenoj otopini. Rezultati pokazuju da su studirani gelatori veoma dobri mediji za skladištenje navedenih lijekova. pH prihvatnog medija ima veliki utjecaj na otpuštanje molekula ibuprofena. Alkalni medij je pogodniji za otpuštanje od kiselog. UVVis spektrofotometrijska sonda je pogodna za praćenje otpuštanja u stvarnom vremenu, no zbog zasićenja prihvatnog pufera ne postižu se visoke stope otpuštanja. Kumulativnom metodom, premještanjem pola volumena prihvatnog medija (0,1M fosfatni pufer, pH 7,4) u kivetu i dodatkom jednake količine nove otopine prihvatnog medija, ne postiže se zasićenje prihvatne otopine te su dobivene više stope otpuštanja. Mehanokemijskim miješanjem hidrogelatora i lipofilnog lijeka, omogućeno je uvođenje lipofilnog lijeka u vodenu fazu i olakšano samoudruživanje u hidrogelu.New controlled drug delivery systems are being developed to improve the therapeutic efficacy of drugs and to keep under control existing side effects. Two tripeptide gelators were synthesized 1. organogelator Z-L-Phe-L-Phe-LAlaNH2 and 2. hydrogelator Ac-L-Phe-L-Phe-L-AlaNH2 with the aim of studying their potential to develop drug depot systems and controlled release systems of nonsteroidal antireumatics (NSAR). After long-term oral administration of NSAR, such as ibuprofen and acetylsalicylic acid, serious side effects may occur in the gastrointestinal tract. Transdermal controlled drug delivery by gels represents an alternative method of drug administration by which unwanted effects are avoided. For the liquid component of organogel a soybean oil was selected, and phosphate buffer was selected for the hydrogel liquid component. Ibuprofen and acetylsalicylic acid were loaded in the tripeptide gels and the release behavior of drugs in phosphate buffer was investigated by using UV-Vis spectroscopy. Further, the influence of the pH values of the accepting media on the release behavior of ibuprofen from organogel was investigated. Release behavior was measured by two different systems. Cumulative, taking the sample through a certain period of time and determining drug concentration using UV Vis spectroscopy (in cuvette cell) or directly using optic probe. The results obtained by different measurement methods were compared. The hydrogelator potential during the mechanochemical reaction of hydrogelator and ibuprofen in the mill was studied in order to improve the solubility of the hydrophobic drug in aqueous solution. The results indicated that studied gelators are very good media for drug depot systems. pH of the accepting media has a major impact on the release behavior of ibuprofen molecules. Alkaline media is more suitable for release. The UV-Vis spectrophotometric probe is suitable for real-time drug delivery monitoring but due to saturation of the accepting buffer, high release rates are not achieved. Cumulative method, by transferring the half volume of the accepting media (0.1M phosphate buffer, pH 7.4) to a cuvette and adding equal amounts of a new solution of the accepting media, the saturation of the accepting solution is not achieved and higher release rates are obtained. By mechanochemical mixing of hydrogelator and lipophilic drug, it is possible to introduce a lipophilic drug into the aqueous phase and facilitate self assembly in the hydrogel

Synthesis and characterization supramolecular hydrogels for the drug delivery and controlled relase

Novi sustavi prijenosa i kontrolirane isporuke lijekova se razvijaju s ciljem poboljšavanja učinkovitosti lijekova i stavljanja pod nadzor postojećih nuspojava. Sintetizirana su dva tripeptidna gelatora 1. organogelator Z-LPhe- L-Phe-L-AlaNH2 i 2. hidrogelator Ac-L-Phe-L-Phe-L-AlaNH2 s ciljem studiranja njihovih potencijala za skladištenje i kontrolirano otpuštanje nesteroidnih antireumatika (NSAR). Nakon dugotrajne oralne uporabe NSAR, poput ibuprofena i acetilsalicilne kiseline mogu se pojaviti ozbiljne nuspojave u gastrointestinalnom traktu. Transdermalna kontrolirana isporuka lijekova pomoću gelova predstavlja alternativnu metodu primjene lijeka pomoću koje se zaobilaze nepoželjni učinci. Za tekuću komponentu organogela odabrano je sojino ulje, a za tekuću komponentu hidrogela vodeni fosfatni pufer. U tripeptidne gelove su ugrađeni ibuprofen i acetilsalicilna kiselina, te se pratilo otpuštanje lijekova ovisno o vremenu u fosfatni pufer pomoću UV-Vis spektroskopije. Nadalje, proučavao se utjecaj pH prihvatnog medija na otpuštanje ibuprofena iz organogela. Otpuštanje je mjereno pomoću dva različita sustava. Kumulativno, uzimanjem uzorka kroz određen vremenski period i određivanjem koncentracije lijeka pomoću UV Vis spektroskopije (u kiveti) ili direktno optičkom sondom. Uspoređivani su rezultati dobiveni različitim metodama mjerenja. Mehanokemijskom reakcijom hidrogelatora i ibuprofena u kugličnom mlinu ispitivao se potencijal hidrogelatora za poboljšanje topljivosti hidrofobnog lijeka u vodenoj otopini. Rezultati pokazuju da su studirani gelatori veoma dobri mediji za skladištenje navedenih lijekova. pH prihvatnog medija ima veliki utjecaj na otpuštanje molekula ibuprofena. Alkalni medij je pogodniji za otpuštanje od kiselog. UVVis spektrofotometrijska sonda je pogodna za praćenje otpuštanja u stvarnom vremenu, no zbog zasićenja prihvatnog pufera ne postižu se visoke stope otpuštanja. Kumulativnom metodom, premještanjem pola volumena prihvatnog medija (0,1M fosfatni pufer, pH 7,4) u kivetu i dodatkom jednake količine nove otopine prihvatnog medija, ne postiže se zasićenje prihvatne otopine te su dobivene više stope otpuštanja. Mehanokemijskim miješanjem hidrogelatora i lipofilnog lijeka, omogućeno je uvođenje lipofilnog lijeka u vodenu fazu i olakšano samoudruživanje u hidrogelu.New controlled drug delivery systems are being developed to improve the therapeutic efficacy of drugs and to keep under control existing side effects. Two tripeptide gelators were synthesized 1. organogelator Z-L-Phe-L-Phe-LAlaNH2 and 2. hydrogelator Ac-L-Phe-L-Phe-L-AlaNH2 with the aim of studying their potential to develop drug depot systems and controlled release systems of nonsteroidal antireumatics (NSAR). After long-term oral administration of NSAR, such as ibuprofen and acetylsalicylic acid, serious side effects may occur in the gastrointestinal tract. Transdermal controlled drug delivery by gels represents an alternative method of drug administration by which unwanted effects are avoided. For the liquid component of organogel a soybean oil was selected, and phosphate buffer was selected for the hydrogel liquid component. Ibuprofen and acetylsalicylic acid were loaded in the tripeptide gels and the release behavior of drugs in phosphate buffer was investigated by using UV-Vis spectroscopy. Further, the influence of the pH values of the accepting media on the release behavior of ibuprofen from organogel was investigated. Release behavior was measured by two different systems. Cumulative, taking the sample through a certain period of time and determining drug concentration using UV Vis spectroscopy (in cuvette cell) or directly using optic probe. The results obtained by different measurement methods were compared. The hydrogelator potential during the mechanochemical reaction of hydrogelator and ibuprofen in the mill was studied in order to improve the solubility of the hydrophobic drug in aqueous solution. The results indicated that studied gelators are very good media for drug depot systems. pH of the accepting media has a major impact on the release behavior of ibuprofen molecules. Alkaline media is more suitable for release. The UV-Vis spectrophotometric probe is suitable for real-time drug delivery monitoring but due to saturation of the accepting buffer, high release rates are not achieved. Cumulative method, by transferring the half volume of the accepting media (0.1M phosphate buffer, pH 7.4) to a cuvette and adding equal amounts of a new solution of the accepting media, the saturation of the accepting solution is not achieved and higher release rates are obtained. By mechanochemical mixing of hydrogelator and lipophilic drug, it is possible to introduce a lipophilic drug into the aqueous phase and facilitate self assembly in the hydrogel

Synthesis and characterization supramolecular hydrogels for the drug delivery and controlled relase

Novi sustavi prijenosa i kontrolirane isporuke lijekova se razvijaju s ciljem poboljšavanja učinkovitosti lijekova i stavljanja pod nadzor postojećih nuspojava. Sintetizirana su dva tripeptidna gelatora 1. organogelator Z-LPhe- L-Phe-L-AlaNH2 i 2. hidrogelator Ac-L-Phe-L-Phe-L-AlaNH2 s ciljem studiranja njihovih potencijala za skladištenje i kontrolirano otpuštanje nesteroidnih antireumatika (NSAR). Nakon dugotrajne oralne uporabe NSAR, poput ibuprofena i acetilsalicilne kiseline mogu se pojaviti ozbiljne nuspojave u gastrointestinalnom traktu. Transdermalna kontrolirana isporuka lijekova pomoću gelova predstavlja alternativnu metodu primjene lijeka pomoću koje se zaobilaze nepoželjni učinci. Za tekuću komponentu organogela odabrano je sojino ulje, a za tekuću komponentu hidrogela vodeni fosfatni pufer. U tripeptidne gelove su ugrađeni ibuprofen i acetilsalicilna kiselina, te se pratilo otpuštanje lijekova ovisno o vremenu u fosfatni pufer pomoću UV-Vis spektroskopije. Nadalje, proučavao se utjecaj pH prihvatnog medija na otpuštanje ibuprofena iz organogela. Otpuštanje je mjereno pomoću dva različita sustava. Kumulativno, uzimanjem uzorka kroz određen vremenski period i određivanjem koncentracije lijeka pomoću UV Vis spektroskopije (u kiveti) ili direktno optičkom sondom. Uspoređivani su rezultati dobiveni različitim metodama mjerenja. Mehanokemijskom reakcijom hidrogelatora i ibuprofena u kugličnom mlinu ispitivao se potencijal hidrogelatora za poboljšanje topljivosti hidrofobnog lijeka u vodenoj otopini. Rezultati pokazuju da su studirani gelatori veoma dobri mediji za skladištenje navedenih lijekova. pH prihvatnog medija ima veliki utjecaj na otpuštanje molekula ibuprofena. Alkalni medij je pogodniji za otpuštanje od kiselog. UVVis spektrofotometrijska sonda je pogodna za praćenje otpuštanja u stvarnom vremenu, no zbog zasićenja prihvatnog pufera ne postižu se visoke stope otpuštanja. Kumulativnom metodom, premještanjem pola volumena prihvatnog medija (0,1M fosfatni pufer, pH 7,4) u kivetu i dodatkom jednake količine nove otopine prihvatnog medija, ne postiže se zasićenje prihvatne otopine te su dobivene više stope otpuštanja. Mehanokemijskim miješanjem hidrogelatora i lipofilnog lijeka, omogućeno je uvođenje lipofilnog lijeka u vodenu fazu i olakšano samoudruživanje u hidrogelu.New controlled drug delivery systems are being developed to improve the therapeutic efficacy of drugs and to keep under control existing side effects. Two tripeptide gelators were synthesized 1. organogelator Z-L-Phe-L-Phe-LAlaNH2 and 2. hydrogelator Ac-L-Phe-L-Phe-L-AlaNH2 with the aim of studying their potential to develop drug depot systems and controlled release systems of nonsteroidal antireumatics (NSAR). After long-term oral administration of NSAR, such as ibuprofen and acetylsalicylic acid, serious side effects may occur in the gastrointestinal tract. Transdermal controlled drug delivery by gels represents an alternative method of drug administration by which unwanted effects are avoided. For the liquid component of organogel a soybean oil was selected, and phosphate buffer was selected for the hydrogel liquid component. Ibuprofen and acetylsalicylic acid were loaded in the tripeptide gels and the release behavior of drugs in phosphate buffer was investigated by using UV-Vis spectroscopy. Further, the influence of the pH values of the accepting media on the release behavior of ibuprofen from organogel was investigated. Release behavior was measured by two different systems. Cumulative, taking the sample through a certain period of time and determining drug concentration using UV Vis spectroscopy (in cuvette cell) or directly using optic probe. The results obtained by different measurement methods were compared. The hydrogelator potential during the mechanochemical reaction of hydrogelator and ibuprofen in the mill was studied in order to improve the solubility of the hydrophobic drug in aqueous solution. The results indicated that studied gelators are very good media for drug depot systems. pH of the accepting media has a major impact on the release behavior of ibuprofen molecules. Alkaline media is more suitable for release. The UV-Vis spectrophotometric probe is suitable for real-time drug delivery monitoring but due to saturation of the accepting buffer, high release rates are not achieved. Cumulative method, by transferring the half volume of the accepting media (0.1M phosphate buffer, pH 7.4) to a cuvette and adding equal amounts of a new solution of the accepting media, the saturation of the accepting solution is not achieved and higher release rates are obtained. By mechanochemical mixing of hydrogelator and lipophilic drug, it is possible to introduce a lipophilic drug into the aqueous phase and facilitate self assembly in the hydrogel

FRANCISELLA - MOLECULAR MECHANISMS OF ADAPTATION TO AMOEBA CELLS

Cilj istraživanja: Francisella tularensis je gram-negativna, fakultativno unutarstanična bakterija koja se često može pronaći u vodenim ekosustavima. F. novicida, F. philomiragia i F. tularensis subsp. holarctica soj LVS mogu inficirati velik broj stanica, uključujući stanice Acanthamoeba castellanii u kojima je životni ciklus bakterije i održavanje u vodenom mikro okolišu nedovoljno razjašnjeno. Cilj navedenog istraživanja je doprinijeti razumijevanju molekularnih mehanizama adaptacije Francisella vrsta na A. castellanii i vodeni okoliš te istražiti otpornost i preživljavanje Francisella nakon stupanja u interakcije s amebama. Materijal i metode: Rezistencija Francisella vrsta nakon životnog ciklusa u A. castellanii i utjecaj kokultivacije na preživljavanje Francisella vrsta u izvorskim vodama ispitani su nasađivanjem bakterija na hranjive podloge te metodama transmisijske elektronske, fluorescentne i svjetlosne mikroskopije. Metodom protočne citometrije i kvantitativnim PCR-om u stvarnom vremenu ispitani su mehanizmi stanične smrti A. castellanii nakon infekcije. Naposlijetku, uloga genskih lokusa FPO i FNO evaluirana je pomoću ameba testa na hranjivoj podlozi. Rezultati: Rezultati ove studije pokazali su da A. castellanii- uzgojene Francisella vrste postaju podložnije djelovanju dezinficijensa, u usporedbi s in vitro uzgojenim bakterijama. Nadalje, Francisella sojevi pokazali su duže preživljavanje i preživljavanje u većem broju u kokulturi s amebama u usporedbi s preživljavanjem u vodama bez ameba. Francisella ne iducira apoptozu i nekrozu stanica A. castellanii, ali povećana ekspresija Atg16, Atg12 i Atg8 gena tijekom perioda infekcije ukazuje da proces autofagije ima važnu ulogu nakon infekcije ameba. Genski lokusi FPO i FNO nemaju ulogu tijekom interakcija F. novicida i A. castellanii što indicira da se F. novicida ne oslanja na T6SS tijekom interakcija s amebama. Zaključak: Neposredno nakon infekcije A. castellanii, Francisella vrste postaju podložnije djelovanju dezinficijensa u pokušaju odupiranja staničnoj smrti od strane ameba. Međutim, nakon dužeg vremenskog perioda kokultivacije, bakterije počinju iskorištavati hranjive tvari ameba i dugoročno bolje preživljavaju u prisustvu ameba. A. castellanii ima važnu ulogu u životnom ciklusu Francisella vrsta.Objectives: Francisella tularensis is a Gram-negative, facultative intracellular bacterium commonly found in aquatic ecosystems. F. novicida, F. philomiragia, and F. tularensis subsp. holarctica strain LVS can infect a wide range of cells, including cells of Acanthamoeba castellanii. The life cycle of the bacterium and its maintenance in the aquatic microenvironment are poorly understood. The aim of the above research is to contribute to the understanding of the molecular mechanisms of Francisella species adaptation to A. castellanii and the aquatic environment, and to investigate Francisella resistance and survival after entering interactions with amoebae. Material and Methods: The post-entry life cycle resistance of Francisella species in A. castellanii and the effect of cocultivation on the survival of Francisella species in source water were investigated by inoculating bacteria onto culture media and using transmission electron, fluorescence, and light microscopy methods. The mechanisms of cell death of A. castellanii after infection were investigated by flow cytometry and quantitative real-time PCR. Finally, the role of FPO and FNO gene loci was evaluated using the amoeba plate test. Results: The results of this study showed that Francisella species cultured within A. castellanii were more susceptible to the effects of disinfectants compared to bacteria cultured in vitro. In addition, Francisella strains survived longer and in greater numbers in coculture with amoebae than in amoeba-free water. Francisella does not induce apoptosis and necrosis of A. castellanii cells, but the increased expression of Atg16, Atg12, and Atg8 genes during the infection period suggests that the autophagy process plays an important role after amoeba infection. The FPO and FNO gene loci do not play a role during interactions between F. novicida and A. castellanii, suggesting that F. novicida does not rely on the T6SS during interactions with amoebae. Conclusion: Immediately after infection of A. castellanii, Francisella species become more susceptible to the effects of disinfectants in an attempt to resist cell death by amoebae. However, after a prolonged period of cocultivation, bacteria begin to utilise amoebae nutrients and survive better in the presence of amoebae in the long term. A. castellanii plays an important role in the life cycle of Francisella species

FRANCISELLA - MOLECULAR MECHANISMS OF ADAPTATION TO AMOEBA CELLS

Cilj istraživanja: Francisella tularensis je gram-negativna, fakultativno unutarstanična bakterija koja se često može pronaći u vodenim ekosustavima. F. novicida, F. philomiragia i F. tularensis subsp. holarctica soj LVS mogu inficirati velik broj stanica, uključujući stanice Acanthamoeba castellanii u kojima je životni ciklus bakterije i održavanje u vodenom mikro okolišu nedovoljno razjašnjeno. Cilj navedenog istraživanja je doprinijeti razumijevanju molekularnih mehanizama adaptacije Francisella vrsta na A. castellanii i vodeni okoliš te istražiti otpornost i preživljavanje Francisella nakon stupanja u interakcije s amebama. Materijal i metode: Rezistencija Francisella vrsta nakon životnog ciklusa u A. castellanii i utjecaj kokultivacije na preživljavanje Francisella vrsta u izvorskim vodama ispitani su nasađivanjem bakterija na hranjive podloge te metodama transmisijske elektronske, fluorescentne i svjetlosne mikroskopije. Metodom protočne citometrije i kvantitativnim PCR-om u stvarnom vremenu ispitani su mehanizmi stanične smrti A. castellanii nakon infekcije. Naposlijetku, uloga genskih lokusa FPO i FNO evaluirana je pomoću ameba testa na hranjivoj podlozi. Rezultati: Rezultati ove studije pokazali su da A. castellanii- uzgojene Francisella vrste postaju podložnije djelovanju dezinficijensa, u usporedbi s in vitro uzgojenim bakterijama. Nadalje, Francisella sojevi pokazali su duže preživljavanje i preživljavanje u većem broju u kokulturi s amebama u usporedbi s preživljavanjem u vodama bez ameba. Francisella ne iducira apoptozu i nekrozu stanica A. castellanii, ali povećana ekspresija Atg16, Atg12 i Atg8 gena tijekom perioda infekcije ukazuje da proces autofagije ima važnu ulogu nakon infekcije ameba. Genski lokusi FPO i FNO nemaju ulogu tijekom interakcija F. novicida i A. castellanii što indicira da se F. novicida ne oslanja na T6SS tijekom interakcija s amebama. Zaključak: Neposredno nakon infekcije A. castellanii, Francisella vrste postaju podložnije djelovanju dezinficijensa u pokušaju odupiranja staničnoj smrti od strane ameba. Međutim, nakon dužeg vremenskog perioda kokultivacije, bakterije počinju iskorištavati hranjive tvari ameba i dugoročno bolje preživljavaju u prisustvu ameba. A. castellanii ima važnu ulogu u životnom ciklusu Francisella vrsta.Objectives: Francisella tularensis is a Gram-negative, facultative intracellular bacterium commonly found in aquatic ecosystems. F. novicida, F. philomiragia, and F. tularensis subsp. holarctica strain LVS can infect a wide range of cells, including cells of Acanthamoeba castellanii. The life cycle of the bacterium and its maintenance in the aquatic microenvironment are poorly understood. The aim of the above research is to contribute to the understanding of the molecular mechanisms of Francisella species adaptation to A. castellanii and the aquatic environment, and to investigate Francisella resistance and survival after entering interactions with amoebae. Material and Methods: The post-entry life cycle resistance of Francisella species in A. castellanii and the effect of cocultivation on the survival of Francisella species in source water were investigated by inoculating bacteria onto culture media and using transmission electron, fluorescence, and light microscopy methods. The mechanisms of cell death of A. castellanii after infection were investigated by flow cytometry and quantitative real-time PCR. Finally, the role of FPO and FNO gene loci was evaluated using the amoeba plate test. Results: The results of this study showed that Francisella species cultured within A. castellanii were more susceptible to the effects of disinfectants compared to bacteria cultured in vitro. In addition, Francisella strains survived longer and in greater numbers in coculture with amoebae than in amoeba-free water. Francisella does not induce apoptosis and necrosis of A. castellanii cells, but the increased expression of Atg16, Atg12, and Atg8 genes during the infection period suggests that the autophagy process plays an important role after amoeba infection. The FPO and FNO gene loci do not play a role during interactions between F. novicida and A. castellanii, suggesting that F. novicida does not rely on the T6SS during interactions with amoebae. Conclusion: Immediately after infection of A. castellanii, Francisella species become more susceptible to the effects of disinfectants in an attempt to resist cell death by amoebae. However, after a prolonged period of cocultivation, bacteria begin to utilise amoebae nutrients and survive better in the presence of amoebae in the long term. A. castellanii plays an important role in the life cycle of Francisella species