1. From nature to lab : sustainable bacterial cellulose production and modification with synthetic biologyVid Potočnik, Selestina Gorgieva, Janja Trček, 2023, pregledni znanstveni članek Opis: Bacterial cellulose (BC) is a macromolecule with versatile applications in medicine, pharmacy, biotechnology, cosmetology, food and food packaging, ecology, and electronics. Although many bacteria synthesize BC, the most efficient BC producers are certain species of the genera Komagataeibacter and Novacetimonas. These are also food-grade bacteria, simplifying their utilization at industrial facilities. The basic principles of BC synthesis are known from studies of Komagataeibacter xylinus, which became a model species for studying BC at genetic and molecular levels. Cellulose can also be of plant origin, but BC surpasses its purity. Moreover, the laboratory production of BC enables in situ modification into functionalized material with incorporated molecules during its synthesis. The possibility of growing Komagataeibacter and Novacetimonas species on various organic substrates and agricultural and food waste compounds also follows the green and sustainable economy principles. Further intervention into BC synthesis was enabled by genetic engineering tools, subsequently directing it into the field of synthetic biology. This review paper presents the development of the fascinating field of BC synthesis at the molecular level, seeking sustainable ways for its production and its applications towards genetic modifications of bacterial strains for producing novel types of living biomaterials using the flexible metabolic machinery of bacteria.
Ključne besede: acetic acid bacteria, bacterial cellulose, sustainable production, agricultural waste, food waste, genetic engineering, synthetic biology, biomaterial, Komagataeibacter, Novacetimonas
Objavljeno v DKUM: 28.03.2024; Ogledov: 279; Prenosov: 42
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2. Razvoj materialov z aktivnim kisikom za hitrejše celjenje ran : magistrsko deloNika Atelšek Hozjan, 2023, magistrsko delo Opis: Magistrsko delo predstavlja sintezo, razvoj in karakterizacijo do sedaj še neobstoječih biorazgradljivih materialov - aerogelov z aktivnim kisikom za namene hitrejšega celjenja ran. Kot vhodna materiala smo uporabili polisaharid ksantan in biopolimer polilaktično kislino (PLA), ki sta biokompatibilna in cenovno dostopna. Ksantan služi kot osnovni material, ki enkapsulira aktivne učinkovine za namene kontroliranega sproščanja, medtem ko PLA izboljša mehanske lastnosti našega materiala.
V sklopu našega raziskovalnega dela smo po sol-gel postopku s kombiniranjem PLA v etil laktatu ter ksantana v vodi pripravili kompozitne hidrogele. S superkritičnim sušenjem smo jih pretvorili v aerogele in okarakterizirali s plinsko adsorpcijo. S tem smo določili velikost specifičnih površin (BET), ki so dosegle vrednosti do 396 m2/g, ter povprečno velikosto in prostornino por v mezoporoznem območju. Izvedli smo tudi termično analizo z DSC/TGA, test nabrekanja in stabilnosti ter z njimi ocenili termično stabilnost in lastnosti razpada materialov. Rezultati so pokazali, da je kombinacija ksantana in PLA podaljšala stabilnost materiala v simulirani telesni tekočini (SBF) tudi do 72 ur. Materiali z večjo vsebnostjo PLA so absorbirali SBF do 67 kratnika svoje mase, kar je najverjetneje posledica boljše stabilnosti v SBF. Sestavo aerogelov in s tem prisotnost posameznih komponent smo potrdili z analizo FT IR. Glede na rezultate karakterizacije smo izbrali dva materiala z najobetavnejšimi lastnostmi, ter v njiju vključili učinkovini, ki ob stiku z rano generirata kisik, ter zdravilno učinkovino deksametazon. Sproščanje kisika iz materiala smo določili s standardno metodo izpodrivanja vode, pri kateri je bila količina izpodrinjene vode neposredno sorazmerna količini nastalega kisika. Meritve smo izvajali 48 ur, rezultati pa so pokazali, da je material sproščal kisik v celotnem časovnem intervalu. Testirali smo tudi sproščanje deksametazona v SBF, ki je bilo uspešno v primeru obeh impregniranih aerogelov. Nazadnje smo preverili antimikrobno delovanje materialov proti bakterijam Escherichia coli in Staphylococcus aureus. Oba aerogela sta inhibirala rast bakterij in s tem izkazala antimikrobno učinkovitost.
Ključne besede: aerogel, aktivni kisik, biomaterial, celjenje kroničnih ran, kontrolirano sproščanje
Objavljeno v DKUM: 18.09.2023; Ogledov: 487; Prenosov: 177
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3. Biomaterials and host versus graft response : a short reviewTomaž Velnar, Gorazd Bunc, Robert Klobucar, Lidija Gradišnik, 2016, pregledni znanstveni članek Opis: Biomaterials and biotechnology are increasing becoming an important area in modern medicine. The main aim in this area is the development of materials, which are biocompatible to normal tissue. Tissue-implant interactions with molecular, biological and cellular characteristics at the implant-tissue interface are important for the use and development of implants. Implantation may cause an inflammatory and immune response in tissue, foreign body reaction, systemic toxicity and imminent infection. Tissue-implant interactions determine the implant life-period. The aims of the study are to consider the biological response to implants. Biomaterials and host reactions to implants and their mechanisms are also briefly discussed.
Ključne besede: host versus graft disease, GVHD, biomaterial, wound healing, transplant, tissue, prosthetic, implants, biological response, complications
Objavljeno v DKUM: 03.08.2017; Ogledov: 1466; Prenosov: 206
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