Alveld hos lam - Kan vi forebygge sjukdommen?

Norsk senter for økologisk landbruk (NORSØK) og Universitetet i Oslo ved Farmasøytisk Institutt og Institutt for biovitenskap har gjennomført et arbeid for å skaffe mer kunnskap om årsaken til sjukdommen alveld hos lam på beite og undersøke muligheten for å finne forebyggende tiltak som kan hindre opptak av giftstoffer som framkaller sjukdommen. Andre samarbeidspartnere i prosjektet har vært NIVA, NIBIO og representanter for landbruksnæringa. Prosjektene har vært finansiert av Landbruksdirektoratet, Regionalt forskningsfond Midt-Norge, FMLA Sogn og Fjordane, FMLA Møre og Romsdal, Møre og Romsdal fylkeskommune. En spørreundersøkelse blant saueholdere i Sogn og Fjordane, Møre og Romsdal, Sør-Trøndelag og Hedmark viser at dødsårsaken hos lam på beite varierer mellom fylkene, og at dette er særlig tydelig når det gjelder alveld. Et annet hovedfunn er at en stor del av tapet av lam på utmarksbeite klassifiseres som «andre sjukdommer» eller «annet», altså at vi ikke har sikker kunnskap om tapsårsak. Forekomsten av alveld varierer mye fra år til år, men 31,7% av produsentene som deltok i spørreundersøkelsen hadde ett eller flere år mistet dyr pga alveld, noe en vurderer som en relativt høg prosentandel. Alveld var vanligst i Nord-Trøndelag, Møre og Romsdal og Sør-Trøndelag, der 22%-39% hadde mistet lam på grunn av alveld i 2014. Sjukdommen alveld skyldes påvirkning av ett eller flere levertoksiske stoffer. Cyanobakterier av artene Stigonema og Symplocastrum er analysert med hensyn på cyanotoksiner etter at de er satt i sammenheng med påvisning av sjukdommen i et utsatt beiteområde i Halsa kommune i Møre og Romsdal. Identifisering og karakterisering av toksiner fra de aktuelle artene er utført i samarbeid med laboratorier i Bad Elster, Tyskland og Trebon, Tsjekkia. Analysearbeidet er ikke endelig sluttført. Et delmål i prosjektet var, på bakgrunn av hypotesen om at det er forekomst av et eller flere levertoksiske stoffer som forårsaker sjukdom, å finne egna form, størrelse og vekt på en bolus som senere kan utvikles til å inneholde toksinfellende kjemikalier og slik kunne bidra til å ta hånd om giftstoffene i fordøyelseskanalen før de kommer over i blodet og forårsaker fysiologisk skade på dyret. Testbolus i tre ulike størrelser (3, 3,5 og 4 cm lengde) er produsert og testa på 6 lam på ca 2 mnd (vekt 16-22 kg). Bolus var lett å gi med en standard applikator som brukes til parasittmiddel. Røntgenfotografering av lamma viste at alle bolusene lå fint plassert i nettmagen etter at de var lagt inn. Oppholdstid på bolus i nettmagen var ca 4 uker, noe vi mener er tilstrekkelig til å være virksomme i den kritiske perioden for utvikling av alveld på utmarksbeite. Bolusene gjorde ikke skade på fordøyelseskanalen. Tilvekst på lamma som fikk bolus var ikke signifikant forskjellig fra kontrollgruppa. Vekt og størrelse på bolusene var hensiktsmessige og kan legges til grunn for videre arbeid. Et annet delmål i prosjektet var å undersøke potensialet til polykationet chitosan som et mulig utfellingsreagens for saponiner som blant annet finnes i romeplanten. Den produserte bolusen ga en kontrollert frisetting av chitosan over tid, avhengig av diameteren på åpningen i lokket på bolusen. Frisettingshastigheten kan derved kontrolleres ved å endre diameteren på åpningen. Det ble sett en tydelig utfelling ved tilsetning av en løsning med saponiner til en løsning med chitosan. Prosjektet har undersøkt og fått bekrefta muligheten for å bruke chitosan som et toksinfellende middel som kan frigis over tid fra en bolus i dyrets fordøyelseskanal. Arbeidet har gitt viktig ny kunnskap og er en nødvendig start på et større og mer omfattende arbeid for å se om vi kan utvikle forebyggende tiltak som i praktisk husdyrhold gir resultater i form av mindre tap, bedre dyrevelferd og bedre økonomi

Production of food-grade microcarriers based on by-products from the food industry to facilitate the expansion of bovine skeletal muscle satellite cells for cultured meat production

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A natural deep eutectic solvent (NADES) as potential excipient in collagen-based products

Natural deep eutectic solvents (NADES) have previously shown antibacterial properties alone or in combination with photosensitizers and light. In this study, we investigated the behavior of the structural protein collagen in a NADES solution. A combination of collagen and NADES adds the unique wound healing properties of collagen to the potential antibacterial effect of the NADES. The behavior of collagen in a NADES composed of citric acid and xylitol and aqueous dilutions thereof was assessed by spectroscopic, calorimetric and viscosity methods. Collagen exhibited variable unfolding properties dependent on the type of material (telo- or atelocollagen) and degree of aqueous dilution of the NADES. The results indicated that both collagen types were susceptible to unfolding in undiluted NADES. Collagen dissolved in highly diluted NADES showed similar results to collagen dissolved in acetic acid (i.e., NADES network possibly maintained). Based on the ability to dissolve collagen while maintaining its structural properties, NADES is regarded as a potential excipient in collagen-based products. This is the first study describing the solubility and structural changes of an extracellular matrix protein in NADES

Interactions of natural deep eutectic solvents (NADES) with artificial and natural membranes

Natural deep eutectic solvents (NADES) are a third type of liquids, apart from water and lipids. NADES show promise as drug carriers in dermal formulations or formulations for local administration in the oral cavity due to their low toxicity, tunability and biodegradability as well as their solubilizing and stabilizing properties. However, a thorough investigation of their effects in a biological system is needed. The present study aimed to investigate the physicochemical properties of six selected NADES and dilutions thereof. Further, the suitability of NADES as vehicles in topical preparations was evaluated through the application of liposome model membranes and ex vivo pig skin models. The effects of NADES on the membrane stability of egg-phosphatidylcholine (Egg-PC) liposomes and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine 16:0 PC (DPPC) liposomes were investigated by physical stability studies, membrane permeability studies, calorimetric analysis and visual representation by transmission electron microscopy (TEM). The liposomes appeared in most cases physically stable for 24 h in NADES, although there were changes in size and morphology most likely related to increased osmolality. Some NADES were also able to disaggregate formed DPPC liposome aggregates. The ex vivo permeation studies indicated a slightly reduced permeability of chloramphenicol through the pig skin after NADES application, which most likely was caused by hydrogen bonding between the NADES and proteins in the skin based on FT-IR-results. Altogether, our findings suggest that NADES are promising drug carriers in new drug delivery systems for topical applications

Sustainable use of rest raw materials: Properties of collagen from turkey (Meleagris gallopavo) and potential pharmaceutical and biomedical applications

publishedVersio

A natural deep eutectic solvent (NADES) as potential excipient in collagen-based products

Natural deep eutectic solvents (NADES) have previously shown antibacterial properties alone or in combination with photosensitizers and light. In this study, we investigated the behavior of the structural protein collagen in a NADES solution. A combination of collagen and NADES adds the unique wound healing properties of collagen to the potential antibacterial effect of the NADES. The behavior of collagen in a NADES composed of citric acid and xylitol and aqueous dilutions thereof was assessed by spectroscopic, calorimetric and viscosity methods. Collagen exhibited variable unfolding properties dependent on the type of material (telo- or atelocollagen) and degree of aqueous dilution of the NADES. The results indicated that both collagen types were susceptible to unfolding in undiluted NADES. Collagen dissolved in highly diluted NADES showed similar results to collagen dissolved in acetic acid (i.e., NADES network possibly maintained). Based on the ability to dissolve collagen while maintaining its structural properties, NADES is regarded as a potential excipient in collagen-based products. This is the first study describing the solubility and structural changes of an extracellular matrix protein in NADES.publishedVersio

Collagen from Turkey (Meleagris gallopavo) tendon: A promising sustainable biomaterial for pharmaceutical use

publishedVersio

Tuning of 2D cultured human fibroblast behavior using lumichrome photocrosslinked collagen hydrogels

Collagen is extensively used in fabrication of hydrogels for biomedical applications but needs improvement after its isolation from tissues due to slow gelation and poor mechanical properties. Crosslinking could tailor such properties. Collagen has previously been crosslinked by chemical or photochemical methods. Chemical crosslinkers are often toxic, and the crosslinking reaction is difficult to control. Photochemical crosslinkers are usually biocompatible compounds that are activated upon irradiation. Riboflavin (vitamin B2), a photochemical crosslinker of collagen, photodegrades to lumichrome upon irradiation. Cyclodextrins have previously been used to increase the aqueous solubility of lumichrome and regulate collagen self-assembly. In this study, lumichrome dissolved by cyclodextrin complexation was used as a photochemical crosslinker of collagen. Lumichrome photocrosslinking reduced the gelation time to 10 s, compared to 90 min for physical crosslinking. The formed hydrogels exhibited increased elasticity, water absorption properties and water holding capacity compared to physically crosslinked collagen hydrogels and riboflavin photocrosslinked collagen hydrogels. Fibroblasts achieved a myofibroblastic phenotype when cultivated in 2D on lumichrome photocrosslinked gels as observed from histology. These biocompatible photocrosslinked hydrogels could have potential applications in biomedical applications, such as wound healing

Tuning of 2D cultured human fibroblast behavior using lumichrome photocrosslinked collagen hydrogels

Collagen is extensively used in fabrication of hydrogels for biomedical applications but needs improvement after its isolation from tissues due to slow gelation and poor mechanical properties. Crosslinking could tailor such properties. Collagen has previously been crosslinked by chemical or photochemical methods. Chemical crosslinkers are often toxic, and the crosslinking reaction is difficult to control. Photochemical crosslinkers are usually biocompatible compounds that are activated upon irradiation. Riboflavin (vitamin B2), a photochemical crosslinker of collagen, photodegrades to lumichrome upon irradiation. Cyclodextrins have previously been used to increase the aqueous solubility of lumichrome and regulate collagen self-assembly. In this study, lumichrome dissolved by cyclodextrin complexation was used as a photochemical crosslinker of collagen. Lumichrome photocrosslinking reduced the gelation time to 10 s, compared to 90 min for physical crosslinking. The formed hydrogels exhibited increased elasticity, water absorption properties and water holding capacity compared to physically crosslinked collagen hydrogels and riboflavin photocrosslinked collagen hydrogels. Fibroblasts achieved a myofibroblastic phenotype when cultivated in 2D on lumichrome photocrosslinked gels as observed from histology. These biocompatible photocrosslinked hydrogels could have potential applications in biomedical applications, such as wound healing.publishedVersio