Corn processing generates thousands of tons of cob husks, which still contains many valuable elements. To make the most of these wastes, they are applied as substrates for biotransformation's procedures. This approach allowed converting or releasing, the elements deposited in the plant material and obtaining valuable products. Thus bioconversion of corn cob husks (CCH) using a fungus of the Fusarium culmorum genus resulted in obtaining silica nanoparticles of defined size and morphology. SEM analysis excluded their presence on the surface of the substrate. FTIR confirmed the presence of siloxane bonds and O-Si-O bonds in post-biotransformation fluid. Using the Heteropoly Blue Method, it was checked that the highest concentration of silica during 16-day biotransformation falls on the 7th day of the process, in which both the substrate sterilization and the process of the biocatalyst starvation were of key importance. Using the STEM and EDX analysis, it was proved that the obtained nanoparticles with a spherical form are structured and their dimensions are ~40 and ~70 nm. ICP-OES proved that the overall process efficiency was 47%. Such nanoparticles can be successfully used in the medical industry.
Yeasts represent a very diverse group of microorganisms, and even strains that are classified as the same species often show a high level of genetic divergence. Yeasts biodiversity is closely related to their applicability. Biotechnological importance of yeast is almost immeasurable. For centuries, people have exploited its enzymatic potential to produce fermented food as bread or alcoholic beverages. Admittedly, yeasts application was initially instinctual, but with science and technology development, these microorganisms got the object of thorough scientific investigations. It must be recognized that yeast represents an excellent scientific model because of its eukaryotic origin and knowledge of genetics of yeast cells as well as metabolism examined in detail. In 1996, the genome of baker yeast Saccharomyces cerevisiae has been elucidated, what opened the opportunity for the global study of the expression and functioning of the eukaryotic genome. Also, currently, an international team is working on the synthesis of the 16 yeast chromosomes by synthetic biology tools, and the results are expected till the end of the year. Nowadays, yeast is regarded as a versatile tool for biotechnological purposes.
Current vascular stents, such as drug eluting stents (DES), have some serious drawbacks, like in stent restenosis and thrombosis. Therefore, other solutions are sought to overcome these post-implantations complications. These include the strategy of biofunctionalization of the stent surface with antibodies that facilitate adhesion of endothelial cells (ECs) or endothelial progenitor cells (EPCs). Rapid re-endothelialization of the surface minimizes the risk of possible complications. In this study, we proposed ammonium acryloyldimethyltaurate/vinylpyrrolidone co-polymer-based surface (AVC), which was mercaptosilanized in order to expose free thiol groups. The presence of free thiol groups allowed for the covalent attachment of CD133 antibodies by disulfide bridges formation between mercaptosilanized surface and cysteine of the protein molecule thiol groups. Various examinations were performed in order to validate the procedure, including attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) and Fourier transform Raman spectroscopy (FT-Raman), atomic force microscopy (AFM) and scanning electron microscopy (SEM). By means of ATR-FTIR spectroscopy presence of the CD133 antibody within coating was confirmed. In vitro studies proved good biocompatibility for blood cells without induction of hemolytic response. Thus, proposed biofunctionalized CD133 antibody AVC surface has shown sufficient stability for adapting as cardiovascular implant coating and biocompatibility. According to conducted in vitro studies, the modified surface can be further tested for applications in various biological systems.
In this study we present the porous silica-based material that can be used for in situ drug delivery, offering effective supply of active compounds regardless its water solubility. To demonstrate usability of this new material, three silica-based materials with different pore size distribution as a matrix for doping with Photolon (Ph) and Protoporphyrin IX (PPIX) photosensitizers, were prepared. These matrices can be used for coating cardiovascular stents used for treatment of the coronary artery disease and enable intravascular photodynamic therapy (PDT), which can modulate the vascular response to injury caused by stent implantation—procedure that should be thought as an alternative for drug eluting stent. The FTIR spectroscopic analysis confirmed that all studied matrices have been successfully functionalized with the target photosensitizers. Atomic force microscopy revealed that resulting photoactive matrices were very smooth, which can limit the implantation damage and reduce the risk of restenosis. No viability loss of human peripheral blood lymphocytes and no erythrocyte hemolysis upon prolonged incubations on matrices indicated good biocompatibility of designed materials. The suitability of photoactive surfaces for PDT was tested in two cell lines relevant to stent implantation: vascular endothelial cells (HUVECs) and vascular smooth muscle cells (VSMC). It was demonstrated that 2 h incubation on the silica matrices was sufficient for uptake of the encapsulated photosensitizers. Moreover, the amount of the absorbed photosensitizer was sufficient for induction of a phototoxic reaction as shown by a rise of the reactive oxygen species in photosensitized VSMC. On the other hand, limited reactive oxygen species (ROS) induction in HUVECs in our experimental set up suggests that the proposed method of PDT may be less harmful for the endothelial cells and may decrease a risk of the restenosis. Presented data clearly demonstrate that porous silica-based matrices are capable of in situ delivery of photosensitizer for PDT of VSMC.