Formation and Investigation of Mechanical, Thermal, Optical and Wetting Properties of Melt-Spun Multifilament Poly(lactic acid) Yarns with Added Rosins.

One method for adding enhancing properties to textile materials is the insertion of natural ingredients into the textile products during the manufacturing or finishing process. The aim of this research is to investigate the formation of biodegradable melt-spun multifilament Poly(lactic acid) (PLA) yarns with different contents (i.e., 5%, 10%, and 15%) of natural material-rosin, also known as colophony. In this study, multifilament yarns were successfully formed from PLA and a natural substance-pine rosin by melt-spinning them at two different draw ratios (i.e., 1.75 and 2.75). The results indicated that a 1.75 draw ratio caused the formation of PLA and PLA/rosin yarns that were brittle. The presence of rosin (i.e., 5% and 10%) in multifilament yarns decreased the mechanical properties of the PLA/rosin melt-spun multifilament yarns' tenacity (cN/tex), breaking tenacity (cN/tex), and tensile strain (%) and elongation at break (%) and increased absorbance in the entire UV region spectra. In addition, the melting point and degree of crystallinity decreased and there was an increase in the wetting angle compared with pure PLA multifilament. The investigation of melt-spun yarns with Raman spectroscopy proved the presence of rosin in PLA melt-spun yarns.

Influence of Myrrh Extracts on the Properties of PLA Films and Melt-Spun Multifilament Yarns.

A possible approach for providing new properties for textiles is the insertion of natural ingredients into the textile product during the process of its manufacture. Myrrh has long been used in medicine as an antibacterial and antifungal material. Polylactide (PLA) is a thermoplastic synthetic biopolymer obtained from renewable resources-and due its biodegradability, is also widely used in medicine. In this study, films and multifilament yarns from modified biodegradable PLA granules with ethanolic and aqueous myrrh extracts were developed and characterized. Optical microscopy was used to determine the surface morphology of PLA/myrrh multifilament yarns. Tensile tests, ultraviolet-visible (UV-vis), differential scanning calorimetry (DSC) were applied to determine, consequently, mechanical, optical properties and degree of crystallinity of PLA/myrrh films and multifilament yarns. The chemical composition of PLA/myrrh multifilament yarns was estimated by Fourier-transform infrared (FTIR) spectroscopy method. The results showed that it is possible to form PLA melt-spun multifilament yarns with myrrh extract. The type of myrrh extract (ethanolic or aqueous) has a significant influence on the mechanical and optical properties of the PLA films and melt-spun yarns. The mechanical properties of PLA films and melt-spun multifilament yarns formed from PLA granules with aqueous myrrh extract decreased 19% and 21% more than PLA with ethanolic extract, respectively. Analysis of UV-vis spectra showed that, due to the yellow hue, the reflectance of PLA films and melt-spun PLA multifilament yarns modified with myrrh extracts decreased exponentially. The DSC test showed that multifilament yarns from PLA modified with aqueous extract had the highest degree of crystallization.

Formation and Investigation of Electrospun Eudragit E100/Oregano Mats.

An electrospun mat of Eudragit E100 (EE100) (a cationic copolymer based on dimethylaminoethyl methacrylate, butyl methacrylate, and methyl methacrylate) was used as a delivery system for oregano ethanolic extract (OEE). Oregano is a biologically active material which is widely used because of the antibacterial and antifungal activity. The oregano herb consists of phenolic compounds, the main of which are rosmarinic acid and from essential oil-carvacrol. Such a material could be an ideal candidate for oral drug systems. The influence of the EE100 concentration in the OEE on the structure of electrospun mats, encapsulation efficiency, dissolution profile, release kinetics and the stability of biologically active compounds was investigated. The concentration of the solution is a critical parameter for the structure and properties of electrospun mats. The diameter of electrospun fibers increased with the increase of EE100 concentration in the OEE. Electrospun mats obtained from 24% to 32% EE100 solutions showed high encapsulation efficiency, quick release and high stability of rosmarinic acid and carvacrol. Dissolution tests showed that 99% of carvacrol and 80% of rosmarinic acid were released after 10 min from electrospun nano-microfiber mats and capsules obtained from such formulations. The stability tests showed that physicochemical properties, dissolution profiles, and rosmarinic acid and carvacrol contents of the formulations were not significantly affected by storage.

Scaffold design for artificial tissue with bone marrow stem cells.

OBJECTIVE: The aim of this study was to test polymeric materials (collagen, fibrin, polyimide film, and polylactic acid) for single- and multi-layer scaffold formation. MATERIALS AND METHODS: In our study, we used rabbit bone marrow stem cells (rBMSCs) and human mesenchymal stem cells (hMSCs) with materials of a different origin for the formation of an artificial scaffold, such as a collagen scaffold, fibrin scaffold produced from clotted rabbit plasma, electrospun poly(lactic acid) (PLA) mats, polyimide film (PI), and the combination of the latter two. Cell imaging was performed 3-14 days after cell cultivation in the scaffolds. Time-lapse imaging was used to determine hMSC mobility on the PI film. RESULTS: Cell incorporation in collagen and clotted fibrin scaffolds was evaluated after 2-week cultivation in vitro. Histological analysis showed that cells penetrated only external layers of the collagen scaffold, while the fibrin clot was populated with rBMSCs through the entire scaffold thickness. As well, cell behavior on the laser micro-structured PI film was analyzed. The mobility of hMSCs on the smooth PI film and the micro-machined surface was 20±2µm/h and 18±4µm/h, respectively. After 3-day cultivation, hMSCs were capable of spreading through the whole 100±10µm-thick layer of the electrospun PLA scaffold and demonstrated that the multilayer scaffold composed of PI and PLA materials ensured a suitable environment for cell growth. CONCLUSIONS: The obtained results suggest that electrospinning technology and femtosecond laser micro-structuring could be employed for the development of multi-layer scaffolds. Different biopolymers, such as PLA, fibrin, and collagen, could be used as appropriate environments for cell inhabitation and as an inner layer of the multi-layer scaffold. PI could be suitable as a barrier blocking cell migration from the scaffold. However, additional studies are needed to determine optimal parameters of inner and outer scaffold layers.

Formation and Biopharmaceutical Characterization of Electrospun PVP Mats with Propolis and Silver Nanoparticles for Fast Releasing Wound Dressing.

Antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory, and anticancer activities of propolis and its ability to stimulate the immune system and promote wound healing make it a proper component for wound dressing materials. Silver nanoparticles are recognized to demonstrate strong antiseptic and antimicrobial activity; thus, it also could be considered in the development of products for wound healing. Combining propolis and silver nanoparticles can result in improved characteristics of products designed for wound healing and care. The aim of this study was to formulate electrospun fast dissolving mats for wound dressing containing propolis ethanolic extract and silver nanoparticles. Produced electrospun nano/microfiber mats were evaluated studying their structure, dissolution rate, release of propolis phenolic compounds and silver nanoparticles, and antimicrobial activity. Biopharmaceutical characterization of electrospun mats demonstrated fast release of propolis phenolic compounds and silver nanoparticles. Evaluation of antimicrobial activity on Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Bacillus cereus, and Candida albicans strains confirmed the ability of electrospun mats to inhibit the growth of the tested microorganisms.