The incorporation of bioactive compounds onto polymer fibrous scaffolds with further control of drug release kinetics is essential to improve the functionality of scaffolds for personalized drug therapy and regenerative medicine. In this study, polymer and hybrid microcapsules were prepared and used as drug carriers, which are further deposited onto polymer microfiber scaffolds [polycaprolactone (PCL), poly(3-hydroxybutyrate) (PHB), and PHB doping with the conductive polyaniline (PANi) of 2 wt % (PHB-PANi)]. The number of immobilized microcapsules decreased with increase in their ζ-potential due to electrostatic repulsion with the negatively charged fiber surface, depending on the polymer used for the scaffold's fabrication. Additionally, the immobilization of the capsules in dynamic mechanical conditions at a frequency of 10 Hz resulted in an increase in the number of the capsules on the fibers with increase in the scaffold piezoelectric response in the order PCL < PHB < PHB-PANi, depending on the chemical composition of the capsules. The immobilization of microcapsules loaded with different bioactive molecules onto the scaffold surface enabled multimodal triggering by physical (ultrasound, laser radiation) and biological (enzymatic treatment) stimuli, providing controllable release of the cargo from scaffolds. Importantly, the microcapsules immobilized onto the surface of the scaffolds did not influence the cell growth, viability, and cell proliferation on the scaffolds. Moreover, the attachment of human mesenchymal stem cells (hMSCs) on the scaffolds revealed that the PHB and PHB-PANi scaffolds promoted adhesion of hMSCs compared to that of the PCL scaffolds. Two bioactive compounds, antibiotic ceftriaxone sodium (CS) and osteogenic factor dexamethasone (DEXA), were chosen to load the microcapsules and demonstrate the antimicrobial properties and osteogenesis of the scaffolds. The modified scaffolds had prolonged release of CS or DEXA, which provided an improved antimicrobial effect, as well as enhanced osteogenic differentiation and mineralization of the scaffolds modified with capsules compared to that of individual scaffolds soaked in CS solution or incubated in an osteogenic medium. Thus, the immobilization of microcapsules provides a simple, convenient way to incorporate bioactive compounds onto polymer scaffolds, which makes these multimodal materials suitable for personalized drug therapy and bone tissue engineering.

While DNA and messenger RNA (mRNA) based therapies are currently changing the biomedical field, the delivery of genetic material remains the key problem preventing the wide introduction of these methods...

The incorporation of bioactive compounds onto polymer fibrous scaffolds is essential to improve the functionality of scaffolds for personalized drug therapy and regenerative medicine. In this study, SiO2 microcapsules were prepared and used as drug carriers, which are further deposited onto polymer microfiber scaffolds [polycaprolactone (PCL), poly(3-hydroxybutyrate) (PHB), and PHB doping with the conductive polyaniline (PANi) of 2 wt % (PHB-PANi)]. The number of immobilized microcapsules decreased with the increase of their ζ-potential due to the electrostatic repulsion forces between capsule wall and the negatively charged fiber surface, given the nature of the polymer used for the scaffold’s fabrication. Additionally, the immobilization of the capsules in dynamic mechanical conditions resulted in an increased number of the capsules attached on the fibers with the increasing of the scaffold piezoelectric response (PCL < PHB < PHB-PANi). Osteogenic factor dexamethasone (DEXA) is chosen for the microcapsules loading in order to demonstrate the osteogenesis of the developed scaffolds. The immobilization of microcapsules provides a simple and convenient way to incorporate bioactive compounds onto polymer scaffolds, which makes these multimodal materials suitable for the personalized drug therapy and bone tissue engineering.

No abstract

No abstract

No abstract

Abstract:This study examines the use of the geographic information systems (GIS) in structural geomorphology to build the model of the crust based on fractal analysis of relief. Fractal theory, developed by B. Mandelbrot, used to determination morpho-bloc divisibility of the Earth's surface. There is the traceable statistically recurring relief structure indicate the appropriate tiered hierarchy of crustal blocks forming the tectonic and kinematic layers. This hypothesis tested on a digital elevation model (DEM) of the White Sea-Kuloi Plateau -an area of tectonic and magmatic activity of the Paleozoic era. Found the correlation of position the kimberlite magmatic bodies with the tectonic blocks certain depth according to a fractal analysis.

It is shown that the exponential of a complex power series up to order n can be implemented via (23/12+ o(1))M (n) binary arithmetic operations over C, where M (n) stands for the (smoothed) complexity of multiplication of polynomials of degree < n in FFT-model. Yet, it is shown how to raise a power series to a constant power with the complexity (27/8 + o(1))M (n).