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Orodispersible films comprise a promising dosage form with a wide range of advantages compared to conventional formulations. The electrospinning process can significantly enhance the relevant characteristics of orodispersible films, e.g., the dissolution rate and the ease of administration. This study involved the use of two types of hydroxypropyl methylcelluloses of low molecular weight obtained from three different manufacturers as the matrix. The SEM, FTIR, RAMAN, and DSC analyses revealed comparable values for all the fabricated materials. However, the mechanical properties of the fibers differed significantly, with electrospun Methocel E5/PEO proving to be particularly brittle. This is probably caused by the different arrangements of substituted methoxy- and hydroxypropyl groups of studied HPMCs. It is hoped that this paper will serve as an example of the extent to which slight differences between HPMC powder batches can dramatically alter the key properties of electrospun orodispersible films.

The increased consumption, overuse, and subsequent difficult removal of pharmaceuticals using conventional processes lead to their rising prevalence in the environment. Adsorption belongs to the most efficient approaches to pharmaceuticals’ removal from wastewater. This study provides insight into the sorption properties of biochar, lignite, and polyamide nanofibers (PA-nanofibers) for sulfamethoxazole, trimethoprim, clarithromycin, azithromycin, and amoxicillin in ultrapure and wastewater treatment plant (WWTP) effluent water. The negative effect of WWTP effluent water was reflected in a reduction of the sorption capacity of biochar by 6.31–72.15%, 25.58–98.55% for lignite, and 4.21–67.71% for PA-nanofibers. Simultaneously, this study investigates the impact of the experimental setup. The sorption capacities were recorded in the range from 0.65 to 2.84 mg g−1 for biochar, 0.04 to 75.73 μg·g−1 for lignite, and 0.53 to 30.54 μg·g−1 for PA-nanofibers during the fixed-bed column tests with WWTP effluent water. Based on the results, biochar appears to be a suitable sorbent for selected pharmaceuticals in field conditions with running water. Lignite and PA represent complementary treatment technology or can act as a carrier for microbial degraders. Performed batch tests with ultrapure and WWTP effluent water and subsequent column tests highlighted the importance of conducting tests with the appropriate matrix and experimental setup to gain a realistic insight into the behavior of the sorbents under environmentally relevant conditions. Graphical Abstract

Active wound dressings are attracting extensive attention in soft tissue repair and regeneration, including bacteria-infected skin wound healing. As the wide use of antibiotics leads to drug resistance we present here a new concept of wound dressings based on the polycaprolactone nanofiber scaffold (NANO) releasing second generation lipophosphonoxin (LPPO) as antibacterial agent. Firstly, we demonstrated in vitro that LPPO released from NANO exerted antibacterial activity while not impairing proliferation/differentiation of fibroblasts and keratinocytes. Secondly, using a mouse model we showed that NANO loaded with LPPO significantly reduced the Staphylococcus aureus counts in infected wounds as evaluated 7 days post-surgery. Furthermore, the rate of degradation and subsequent LPPO release in infected wounds was also facilitated by lytic enzymes secreted by inoculated bacteria. Finally, LPPO displayed negligible to no systemic absorption. In conclusion, the composite antibacterial NANO-LPPO-based dressing reduces the bacterial load and promotes skin repair, with the potential to treat wounds in clinical settings.

Lignin, a cheap renewable natural polymer, can be used as a precursor for the production of carbon fibres, its conversion into which is significantly faster than that of polyacrylonitrile. Lignin can be fractionated in various solvents via dissolution to decrease its polydispersity. Fractions with a higher molecular weight distribution can then be used in solvent-based spinning technologies such as electrospinning. We selected several solvent systems according to the Hansen solubility theory and subsequently tested them for solubility and electro-spinability. The selected solvent systems were then successfully tested for use in the needleless electrospinning process due to their potential for mass production. The solutions used in the electrospinning process needed high concentrations of lignin, which led to a high degree of viscosity. Therefore, we measured the relaxation times and viskosity for selected solutions, a factor that plays a pivotal role in terms of the production of smooth fibres. Finally, these solutions were tested for electrospinning using alternating current. This technology brings a new possibility in mass production of lignin fibres due to its high productivity and ease of use. Such materials can be used in a number of applications such as batteries, supercapacitors or for the production of composite materials. They provide a cheap and renewable natural polymer source which can easily be transformed into a carbon nanofibrous layer.

A considerable number of experimental studies have been conducted on drug release from nanofibers. However, only a small number of attempts have been made to determine a mechanistic approach to the kinetics of drug release from nanofibers. This paper describes the fabrication of electrospun nanofibers from Poly-e-caprolactone with different loadings of Alaptide aimed at the examination of a mechanistic model based on the solution of the diffusion equation in cylindrical coordinates. The model took into account the weighting of the distribution of the fiber diameters inside the nanofiber membrane. The results revealed that it was possible to describe the release of all the loadings and the forms of the drug inside the fibers using the diffusion equation. The estimated diffusion coefficients were 3.10 ± 1.07 × 10−13, 1.18 ± 0.10 × 10−13 cm2/s and 1.11 ± 0.14 × 10−14 cm2/s for 0.1, 1 and 2.5 wt% of Alaptide loadings, respectively. The estimated values of the diffusion coefficients correlated with the concentration in which Alaptide was present in the fibers. It is anticipated that this model extension will help to enhance the versatility of the approach to the quantification of the amount of released drug, since it can be applied to highly-heterogeneous nanofibrous layers with wide diameter distributions.

We have prepared a candidate biocompatible construct for skin wound healing based on electrospun polycaprolactone (PCL) nanofibrous membranes. The membrane material was loaded either with L-arginine or with alaptide, or with a mixture of both bioactive components. Alaptide is a spirocyclic synthetic dipeptide, an analogue of melanocyte-stimulating hormone release-inhibiting factor. L-arginine is an amino acid with a basic guanidine side chain. It is a direct precursor of nitric oxide, which plays a pivotal role in skin repair. The presence and the distribution of the additives were proved with high-performance liquid chromatography, Fourier-transform infrared spectroscopy and Raman spectroscopy. The influence of L-arginine and alaptide on the morphology of the membrane was characterized using scanning electron microscopy. No statistically significant correlation between fiber diameter and drug concentration was observed. The membranes were then tested in vitro for their cytotoxicity, using primary human dermal fibroblasts, in order to obtain the optimal concentrations of the additives for in vivo tests in a rat model. The membranes with the highest concentration of L-arginine (10 wt. %) proved to be cytotoxic. The membranes with alaptide in concentrations from 0.1 to 2.5 wt.%, and with the other L-arginine concentrations (1 and 5 wt.%), did not show high toxicity. In addition, there was no observed improvement in cell proliferation on the membranes. The in vivo experiments revealed that membranes with 1.5 wt.% of alaptide or with 1.5 wt.% of alaptide in combination with 5 wt.% of L-arginine markedly accelerated the healing of skin incisions, and particularly the healing of skin burns, i.e. wounds of relatively large extent. These results indicate that our newly-developed nanofibrous membranes are promising for treating wounds with large damaged areas, where a supporting material is needed.