Репозиторий Университета

© 2018 IEEE. Technique of laser microsurgery of cell spheroids with nanosecond laser pulses was used to develop a new simple reproducible model for studying regeneration in vitro. Wound restoration accompanying the reparative processes occurred gradually over seven days due to rearrangement of surviving non-proliferating cells. Skin anti-ageing drugs can be tested on the developed model of cell spheroid's regeneration.

©2018 by the authors. Licensee MDPI, Basel, Switzerland. Engineering of a “smart” drug delivery system to specifically target tumour cells has been at the forefront of cancer research, having been engineered for safer, more efficient and effective use of chemotherapy for the treatment of cancer. However, selective targeting and choosing the right cancer surface biomarker are critical for a targeted treatment to work. Currently, the available delivery systems use a two-dimensional monolayer of cancer cells to test the efficacy of the drug delivery system, but designing a “smart” drug delivery system to be specific for a tumour in vivo and to penetrate the inner core remains a major design challenge. These challenges can be overcome by using a study model that integrates the three-dimensional aspect of a tumour in a culture system. Here, we tested the efficacy of a functionalized folic acid-conjugated amphiphilic alternating copolymer poly(styrene-alt-maleic anhydride) (FA-DABA-SMA) via a biodegradable linker 2,4-diaminobutyric acid (DABA) to specifically target and penetrate the inner core of three-dimensional avascular human pancreatic and breast tumour spheroids in culture. The copolymer was quantitatively analyzed for its hydrophobic drug encapsulation efficiency using three different chemical drug structures with different molecular weights. Their release profiles and tumour targeting properties at various concentrations and pH environments were also characterized. Using the anticancer drug curcumin and two standard clinical chemotherapeutic hydrophobic drugs, paclitaxel and 5-fluorouracil, we tested the ability of FA-DABA-SMA nanoparticles to encapsulate the differently sized drugs and deliver them to kill monolayer pancreatic cancer cells using the WST-1 cell proliferation assay. The findings of this study revealed that the functionalized folic acid-conjugated amphiphilic alternating copolymer shows unique properties as an active “smart” tumor-targeting drug delivery system with the ability to internalize hydrophobic drugs and release the chemotherapeutics for effective killing of cancer cells. The novelty of the study is the first to demonstrate a functionalized “smart” drug delivery system encapsulated with a hydrophobic drug effectively targeting and penetrating the inner core of pancreatic and breast cancer spheroids and reducing their volumes in a dose-and time-dependent manner.

© 2018 IOP Publishing Ltd. Maintaining the epithelial status of cells in vitro and fabrication of a multilayered epithelial lining is one of the key problems in the therapy using cell technologies. When cultured in a monolayer, epithelial cells change their phenotype from epithelial to epithelial-mesenchymal or mesenchymal that makes it difficult to obtain a sufficient number of cells in a 2D culture and to use them in tissue engineering. Here, using buccal epithelial cells from the oral mucosa, we developed a novel approach to recover and maintain the stable cell phenotype and form a multilayered epithelial lining in vitro via the 2D/3D cell self-assembling. Transitioning the cells from the monolayer to non-adhesive 3D culture conditions led to formation of self-assembling spheroids, with restoration of their epithelial characteristics after epithelial-mesenchymal transition. In 7 days, the cells within spheroids restored the apical-basal polarity, and the formation of both tight (ZO1) and adherent (E-cadherin) intercellular junctions was shown. Thus, culturing buccal epithelial cells in a 3D system allowed us to recover and durably maintain the morphological and functional characteristics of epithelial cells. The multilayered epithelial lining formation was achieved after placing spheroids for 7 days onto a hybrid matrix, which consisted of collagen layers and reinforcing poly (lactide-co-glycolide) fibers and was proven promising for replacement of the urothelium. Thus, we offer an effective technique of forming multilayered epithelial linings on carrier-matrices using cell spheroids that was not previously described elsewhere and can find a wide range of applications in tissue engineering, replacement surgery, and regenerative medicine.

© 2018 Elsevier B.V. Development of efficient biodegradable, environmentally responsive, biocompatible and non-toxic delivery system is needed for efficient gene delivery. As well known, properties of the vehicle are determined by the structure of carrier components. The aim of the current study was to estimate in vitro transfection efficacy of aliphatic di-, tri- and tetrapeptide-based cationic lipoplexes loaded with siRNA in function of a number of cationic groups using 2D (monolayer culture) and 3D (multicellular tumor spheroids) in vitro models. Physicochemical properties and cytotoxicity of the liposomes were found to be dependent upon a number of amino acid derivatives in an amphiphilic polar head. Uptake of liposomes loaded with nucleic acid (lipoplexes) and their localization in HEK293T cells was studied by confocal microscopy. The liposomes based on lipotripeptides had the highest transfection efficiency which was 20-fold higher than those fabricated from lipotetrapeptides.

© 2018 IOP Publishing Ltd. One of the essential goals in regenerative medicine is microvascularization which enables an effective blood supply within de novo constructed tissues and organs. In our study, we used two common multipotent mesenchymal stromal cell (MMSC) sources (subcutaneous adipose tissue and Wharton's jelly of the umbilical cord) where is a subpopulation of endothelial precursors. In the medium supplemented with VEGF, the 3D cultures of UC MMSCs and ADSCs promoted the endothelial cell differentiation. To evaluate their ability to form a capillary-like network, we encapsulated spheroids within non-modified and PEGylated fibrin hydrogels. The PEGylated hydrogel supported better the formation of multibranched cords than the pure fibrin gel. Analysis of tubule growth rate, length, and branching showed that the differentiated ADSCs had higher angiogenic potential than the differentiated hUC MMSCs. Our study can be a basis for the development of new strategies in tissue engineering and treatment of vascular diseases.

© The Author(s) 2018. Objective: Chondrospheres represent a variant of tissue spheroids biofabricated from chondrocytes. They are already being used in clinical trials for cartilage repair; however, their biomechanical properties have not been systematically investigated yet. The aim of our study was to characterize chondrospheres in long-term in vitro culture conditions for morphometric changes, biomechanical integrity, and their fusion and spreading kinetics. Results: It has been demonstrated that the increase in chondrospheres secant modulus of elasticity is strongly associated with the synthesis and accumulation of extracellular matrix. Additionally, significant interplay has been found between biomechanical properties of tissue spheroids and their fusion kinetics in contrast to their spreading kinetics. Conclusions: Extracellular matrix is one of the main structural determinants of chondrospheres biomechanical properties during chondrogenic maturation in vitro. The estimation of tissue spheroids’ physical behavior in vitro prior to operative treatment can be used to predict and potentially control fusogenic self-assembly process after implantation in vivo.