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Polyaniline is an organic semiconductor. It is prepared by the oxidative chemical or electrochemical oxidations of aniline in acidic aqueous media. The course of the oxidation can be followed by monitoring changes in temperature or pH. Depending on acidity conditions, polyaniline has globular, nanofibrilar, or nanotubular morphology. Polyaniline may also be obtained as thin films, coatings, or as colloidal dispersions. The conducting polyaniline salt convers to nonconducting polyaniline base under alkaline conditions. Its reprotonation by various acids offers a route for preparation of polyanilines with various properties. These processes are reflected in UV–vis, FTIR, and Raman spectra. The mechanism of conduction is based on the presence of delocalized polarons and protons. Polyaniline exhibits both the electronic and ionic conductivity. The stability of polyaniline at elevated temperature and in aggressive media is good. Polyaniline is converted to nitrogen‐containing carbon in inert atmosphere at 600°C. Biological properties and antimicrobial activity of polyaniline are outlined. The applications of polyaniline in batteries, corrosion protection, fuel cells, sensors, and supercapacitors are briefly reviewed.

In this study, sodium alginate/gelatine (SA/G) hydrogels were prepared to obtain wound dressing with good, moist, healing, and biocompatibility properties. The physicochemical properties of hydrogels were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy, and a swelling test. Dynamic viscoelastic properties including the storage, loss moduli, G 0 and G 00 , and loss angle, tan delta of both freshly prepared and swelled gels were examined in oscillatory experiments. Its results revealed that tested SA/G hydrogels exhibit highly elastic behavior similar to the viscoelastic response of human skin. Based on the performed analysis, it could be suggested that the SA/G hydrogel is a potential wound dressing material providing and maintaining the adequate moist environment required to prevent scab formation and the dehydration of the wound bed.

The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of Cannabis sativa L. in refined and unrefined form was characterized using iodine, saponification, acid values, and gas chromatography, and was employed for the preparation of stable oil-in-water emulsions. The emulsions were prepared using pairs of non-ionic surfactants (Tween, Span). The effects of the emulsification method (spontaneous emulsification vs. high-intensity stirring), hydrophilic lipophilic balance (HLB), type and concentration of surfactant, and oil type on the size and distribution of the emulsion particles were investigated. It was found that the ability to form stable emulsions with small, initial particle sizes is primarily dependent on the given method of preparation and the HLB value. The most efficient method of emulsification that afforded the best emulsions with the smallest particles (151 ± 1 nm) comprised the high-energy method, and emulsions stable over the long-term were observed at HBL 9 with 10 wt % concentration of surfactants. Under high-intensity emulsification, refined and unrefined oils performed similarly. The oils as well as their emulsions were tested against the growth of selected bacteria using the disk diffusion and broth microdilution methods. The antibacterial effect of hemp seed oil was documented against Micrococcus luteus and Staphylococcus aureus subsp. aureus. The formulated emulsions did not exhibit the antibacterial activity that had been anticipated.

Conducting polymers (CP), namely polyaniline (PANI) and polypyrrole (PPy), are promising materials applicable for the use as biointerfaces as they intrinsically combine electronic and ionic conductivity. Although a number of works have employed PANI or PPy in the preparation of copolymers, composites, and blends with other polymers, there is no systematic study dealing with the comparison of their fundamental biological properties. The present study, therefore, compares the biocompatibility of PANI and PPy in terms of cytotoxicity (using NIH/3T3 fibroblasts and embryonic stem cells) and embryotoxicity (their impact on erythropoiesis and cardiomyogenesis within embryonic bodies). The novelty of the study lies not only in the fact that embryotoxicity is presented for the first time for both studied polymers, but also in the elimination of inter-laboratory variations within the testing, such variation making the comparison of previously published works difficult. The results clearly show that there is a bigger difference between the biocompatibility of the respective polymers in their salt and base forms than between PANI and PPy as such. PANI and PPy can, therefore, be similarly applied in biomedicine when solely their biological properties are considered. Impurity content detected by mass spectroscopy is presented. These results can change the generally accepted opinion of the scientific community on better biocompatibility of PPy in comparison with PANI.

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