Production and characterization of non-mineralized and mineralized biomaterials based on seaweed polysaccharides and essential metal zinc

U ovoj tezi je ispitana mogućnost sinteze novih, poboljšanih biomaterijala na bazi alginata, agara i cinka, primenom biomimetičkog principa dizajna – biomineralizacije. Cilj istraživanja je bio dizajn i karakterizacija novih nanokompozitnih biomaterijala, sa potencijalnom primenom u biomedicini i pakovanju hrane...The aim of this study was to test the hypothesis whether biopolymer-based biomineralization, with essential metal salts, Zn-minerals, can be considered a good platform for designing nanocomposite biomaterials for potential biomedical and active food packaging applications..

Transport of silver nanoparticles from nanocomposite Ag/alginate hydrogels under conditions mimicking tissue implantation

The aim of this work was to assess phenomena occurring during AgNP transport from nanocomposite Ag/alginate hydrogels under conditions relevant for potential biomedical applications as antimicrobial soft tissue implants. First, we have studied AgNP migration from the nanocomposite to the adjacent alginate hydrogel mimicking soft tissue next to the implant. AgNP deposition was carried out by the initial burst release lasting for similar to 24 h yielding large aggregates on hydrogel surfaces and smaller clusters (similar to 400 nm in size) inside. However, the overall released content was low (0.67%) indicating high nanocomposite stability. In the next experimental series, release of AgNPs, 10-30 nm in size, from Ag/alginate microbeads in water was investigated under static conditions as well as under continuous perfusion mimicking vascularized tissues. Mathematical modeling has revealed AgNP release by diffusion under static conditions with the diffusion coefficient within the Ag/alginate hydrogel of 6.9x10(-19) m(2) s(-1). Conversely, continuous perfusion induced increased AgNP release by convection with the interstitial fluid velocity estimated as 4.6 nm s(-1). Overall, the obtained results indicated the influence of hydrodynamic conditions at the implantation site on silver release and potential implant functionality, which should be investigated at the experimentation beginning using appropriate in vitro systems

Mineralized agar-based nanocomposite films: Potential food packaging materials with antimicrobial properties

New mineralized, agar-based nanocomposite films (Zn-carbonate and Zn-phosphate/agar) were produced by a combination of in situ precipitation and a casting method. The presence of minerals significantly influenced the morphology, properties and functionality of the obtained nanocomposites. Reinforcement with the Zn-mineral phase improved the mechanical properties of the carbonate-mineralized films, but had a negligible effect on the phosphate-mineralized samples. Both nanocomposites showed improved optical and thermal properties, better Zn(II) release potential in a slightly acidic environment and exhibited antimicrobial activity against S. aureus. These results suggest that Zn-mineralized agar nanocomposite films could be potentially used as affordable, eco-friendly and active food packaging materials.This is the peer reviewed version of the paper: Malagurski, I., Levic, S., Nesic, A., Mitric, M., Pavlovic, V., & Dimitrijevic-Brankovic, S. (2017). Mineralized agar-based nanocomposite films: Potential food packaging materials with antimicrobial properties. Carbohydrate Polymers, 175, 55–62. [https://doi.org/10.1016/j.carbpol.2017.07.064][https://www.sciencedirect.com/science/article/abs/pii/S0144861717308408?via%3Dihub

Synthesis and antimicrobial properties of Zn-mineralized alginate nanocomposites

New bioactive and antimicrobial biomaterials were produced by alginate-mediated biomineralization with Zn-mineral phase. The synthesis procedure is simple, cost-effective and resulted in. two different Zn-mineralized alginate nanocomposites, Zn-carbonate/Zn-alginate and Zn-phosphate/Zn-alginate. The presence of Zn-mineral phase and its type, have significantly affected nanocomposite morphology, stability, total metallic loading and potential to release Zn(II) in physiological environment. Antimicrobial experiments showed that both types of Zn-mineralized nanocomposites exhibit strong antimicrobial effect against Escherichia coli, Staphylococcus aureus and Candida albicans. These results suggest that alginate biomineralization, where minerals are salts of essential metallic ions like Zn(II), represents a'good strategy for designing multifunctional biomaterials for potential biomedical applications.This is the peer reviewed version of the paper: Malagurski, I., Levic, S., Pantic, M., Matijasevic, D., Mitric, M., Pavlovic, V., & Dimitrijevic-Brankovic, S. (2017). Synthesis and antimicrobial properties of Zn-mineralized alginate nanocomposites. Carbohydrate Polymers, 165, 313–321. [https://doi.org/10.1016/j.carbpol.2017.02.064

Medium chain length (mcl)-pha-based nanocomposites for biomedical applications: system evaluation through xrd

Medium-chain polyhydroxyalkanoates (mcl-PHA) are flexible, elastomeric polymers produced by wide range of bacteria as intercellular storage of carbon and energy. They represent attractive components in biomaterial design because they are biocompatible, biodegradable and can be obtained using variety of carbon sources including waste streams[1]. However, being semi-crystalline, all mcl-PHAs are characterized by low melting temperature and poor tensile strength which can interfere with processing methods and wider biomedical application. Simple way to improve mcl-PHAs properties is to incorporate a nanophase within biopolymer to obtain nanocomposites. Nano-sized constituents interact with biopolymer more intimately affecting in turn the obtained nanocomposite properties as well as functionality. Among inorganic nanofillers, TiO2 nanostructures with high aspect ratio (e.g. nanofibers) have unique properties that support osteogenic phenotype which makes them suitable for bone tissue engineering [2]

UV-blocking sustainable food packaging based on polyhydroxyalkanoate and bacterial pigment prodigiosin

New film materials based on bacterial biomolecules polyhydroxyalkanoate (poly(3- hydroxybutyrate-co-3-hydroxyvalerate) PHBV) and prodigiosin (PG) were produced by solvent casting as a potential food packaging material. Film precursors were obtained in a sustainable manner via microbial fermentation using waste stream-based substrates (cooking oil and second-grade canned meat, after the expiry date). The incorporation of PG into the PHBV has influenced the morphology and functionality of the obtained materials. PG acted as a nucleating agent, affecting in turn PHBV/PG film surface morphology. The films were intensively colored, transparent and blocked UV-light. An increase in PG content decreased film transparency but it did not affect UV-blocking ability. Migration experiments have shown that films possess the potential to release PG into lipophilic food simulant media where it has exhibited antioxidative action. The obtained results suggest that PHBV/PG films can be potentially used as sustainable and active food packaging materials.2nd International Conference on Chemo and BioInformatics, ICCBIKG 2023, September 28-29, 2023 Kragujeva

Active agar mineralized composite films intended for food packaging

Polysaccharide-based materials represent an attractive alternative to plastics, due to their biodegradability, compatibility and great film forming properties1. As they are usually characterized by poor mechanical and barrier properties and lack of functionality, different components must be incorporated into these biopolymer materials in order to improve their properties. In this study, new mineralized, agar-based composite films with increasing Cu-phosphate mineral phase loadings (1, 2.5 and 5 mM) were prepared by in situ mineralization and solvent casting method. The presence of mineral significantly influenced the morphology, properties and fun- ctionality of the obtained composite films. Reinforcement with the Cu-phosphate phase improved in a concentration-dependent manner, optical, mechanical and water vapor barrier properties of the obtained mine- ralized films. In addition Cu-phosphate mineralized agar films exhibited antimicrobial activity against both, Gram positive and Gram negative bacteria, Staphylococcus aureus and Escherichia coli, respectively. The res- ults of this study suggest that agar films mineralized with Cu-phosphate could be potentially used as affordable, eco-friendly and functional food packaging materials with tunable properties. Production procedure offers possibilities for increasing Cu-mineral phase content without compromising properties of the composite films

Conversion of mixed plastic waste containing PET into biopolymer bacterial nanocellulose

The rapid increase in global plastics production is also causing an accelerated environmental pollution. Recently, biotechnological solutions and enzymatic recycling of poly(ethylene terephthalate) (PET) waste stream have been put forward and commercialized1. Increasing recycling and upcycling rates is the most effective model approach to plastic circularity. However, mixed plastic waste is still quite a challenge for both recycling and upcycling technologies. This study is focused on the eco-conversion of plastic waste containing poly(ethylene terephthalate), PET, into biopolymer, bacterial nanocellulose. Polymer mix contained selection of commercial biodegradable plastics (poly(lactic acid), PLA, poly(ε-caprolactone), PCL, poly(hyoxyl butyrate), PHB) and PET. This mixture was hydrolysed under aqueous conditions and hydrolysate was used as carbon source for Komagataeibacter medellinensis ID13488 and bacterial nanocellulose (BNC) production. HPLC analysis confirmed the presence of monomers and dimers of polymer mix components indicating existence of potential substrates for BNC production. BNC production by K. medellinensis was investigated and optimized in ter of the amount of carbon source and growth conditions. Under the most efficient rate in ter of yield, BNC production was scaled up and the obtained biopolymer was characterized. The structure of produced BNC was confirmed by FTIR analysis, thermal properties by DSC/TG analysis, and the morphology of material by optical microscopy and SEM analysis. This research demonstrates how to put the mixed plastic waste stream into a circular loop through the biotechnological conversion into valuable biopolymer.10th International Conference of MIKROBIOKOSMOS, Larissa from 30 Novewmber to 2 December 2023

Advancing PHBV Biomedical Potential with the Incorporation of Bacterial Biopigment Prodigiosin

The quest for sustainable biomaterials with excellent biocompatibility and tailorable properties has put polyhydroxyalkanoates (PHAs) into the research spotlight. However, high production costs and the lack of bioactivity limit their market penetration. To address this, poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was combined with a bacterial pigment with strong anticancer activity, prodigiosin (PG), to obtain functionally enhanced PHBV-based biomaterials. The samples were produced in the form of films 115.6–118.8 m in thickness using the solvent casting method. The effects of PG incorporation on the physical properties (morphology, biopolymer crystallinity and thermal stability) and functionality of the obtained biomaterials were investigated. PG has acted as a nucleating agent, in turn affecting the degree of crystallinity, thermal stability and morphology of the films. All samples with PG had a more organized internal structure and higher melting and degradation temperatures. The calculated degree of crystallinity of the PHBV copolymer was 53%, while the PG1, PG3 and PG3 films had values of 64.0%, 63.9% and 69.2%, respectively. Cytotoxicity studies have shown the excellent anticancer activity of films against HCT116 (colon cancer) cells, thus advancing PHBV biomedical application potential

Supplementary data for article: Solarz, D., Witko, T., Karcz, R., Malagurski, I., Ponjavić, M., Levic, S., Nešić, A., Guzik, M., Savić, S.,& Nikodinović-Runić, J.. (2023). Biological and physiochemical studies of electrospun polylactid/polyhydroxyoctanoate PLA/ P(3HO) scaffolds for tissue engineering applications. in RSC Advances, 13(34), 24112-24128. https://doi.org/10.1039/D3RA03021K

Polyhydroxyoctanoate, as a biocompatible and biodegradable biopolymer, represents an ideal candidate for biomedical applications. However, physical properties make it unsuitable for electrospinning, currently the most widely used technique for fabrication of fibrous scaffolds. To overcome this, it was blended with polylactic acid and polymer blend fibrous biomaterials were produced by electrospinning. The obtained PLA/PHO fibers were cylindrical, smaller in size, more hydrophilic and had a higher degree of biopolymer crystallinity and more favorable mechanical properties in comparison to the pure PLA sample. Cytotoxicity evaluation with human lung fibroblasts (MRC5 cells) combined with confocal microscopy were used to visualize mouse embryonic fibroblasts (MEF 3T3 cell line) migration and distribution showed that PLA/PHO samples support exceptional cell adhesion and viability, indicating excellent biocompatibility. The obtained results suggest that PLA/PHO fibrous biomaterials can be potentially used as biocompatible, biomimetic scaffolds for tissue engineering applications.Supplementary material for:[https://doi.org/10.1039/D3RA03021K]Related to published version: [https://imagine.imgge.bg.ac.rs/handle/123456789/2059