Polimery w medycynie最新文献

Black pepper (Piper nigrum L.) is a climbing perennial plant in the Piperaceae family. Pepper has been known since antiquity for its use both as a medicine and a spice. It is particularly valued for its pungency attributed to its principal constituent - piperine. This review summarizes the information on the biological source of piperine, its extraction and isolation strategies, physicochemical properties, and pharmacological activity - analgesic, immunomodulatory, anti-depressive, anti-diarrheal, hepatoprotective, etc. The effect of piperine on biotransformation of co-administered drugs is also presented in this review, along with the mechanisms involved in its bioavailability-enhancing effect. Its important medicinal uses, including anti-hepatotoxic, anti-diarrheal, anti-depressive, analgesic, and immunomodulatory effects, besides many other traditional uses, are compiled. Based on an exhaustive review of literature, it may be concluded that piperine is a very promising alkaloid found in members of the Piperaceae family.

Background: Resin composites have various applications. At the same time, they have some drawbacks, such as polymerization shrinkage. Conventional composites are polymerized in 2-mm thick layers. However, in posterior restoration, the 2-mm depth of cure is not satisfactory. To find a solution, resin composites have been vastly improved in terms of fillers, matrix and initiators.

Objectives: To evaluate polymerization properties and physical characteristics of fiber-reinforced composites and compare them with bulk-fill composites that are designed for large posterior restorations.

Material and methods: Samples were prepared from each resin composite. The 3-point bending test was performed to evaluate the flexural strength of all composites. The depth of cure of the composite from 1 mm to 4 mm of depth was analyzed using Vickers hardness test (VHN). To analyze the degree of conversion, Fourier-transform infrared spectroscopy (FTIR) of the top and bottom surfaces of the samples with 4-mm thickness was calculated. The data were analyzed using one-way analysis of variance (ANOVA) test followed by post hoc test (95% confidence interval (95% CI)).

Results: The Filtek showed the highest flexural strength followed by everX and X-tra fil. At 1-mm depth, X-tra fil had the highest and Gradia had the lowest microhardness. At the 4-mm depth, the microhardness trend was as follows: everX > Filtek > X-tra fil > Gradia > Beautifil. The everX composite had the lowest reduction of the degree of conversion at 4-mm thickness, which showed a significant difference in comparison with Filtek, Gradia and X-tra fil composites.

Conclusions: Based on the results of our study, it can be concluded that the fiber-reinforced composite everX showed more favorable results regarding polymerization properties, such as the degree of conversion and the depth of cure. However, the flexural strength results in Filtek were better than those in everX.

Background: Gamma-polyglutamic acid (γ-PGA) is a microbially produced non-toxic peptide biopolymer which is gaining grounds in many biotechnological fields and has a wide range of applications.

Objectives: In this study, the characteristics of γ-PGA produced by Bacillus megaterium isolated from an oil seed were determined, while the nutritional requirements of the bacterium were optimized using a predictive 15 factor-16 run Plackett-Burman experimental design.

Material and methods: The main effect of each factor, the interaction and quadratic effects of the factors on optimized production were determined from Box-Benkhen model using Dell Statistica v. 12 and 13 software. Bacillus megaterium UP47 produced the highest γ-PGA (16.33 g/L) out of 56 spore-forming Bacillus strains isolated from soil, water and fermented food samples.

Results: Hydrolysates of the produced γ-PGA had a retention factor which corresponded to the L-glutamic acid standard (retention factor (rf) 0.35), while high-definition fourier transform infrared (FT-IR) spectroscopic imaging showed characteristic peaks representative of the active bonds present in γ-PGA. The γ-PGA at a concentration as low as 50 mg/100 mL exerted antimicrobial inhibitions against test pathogens. A 2.00 w/v γ-PGA solution had 11 mm and 13 mm inhibition zones against Staphylococcus aureus and Shigella dysenteriae, respectively. A second order polynomial equation for prediction of γ-PGA was derived as: γPGA yield = 3316.061 - 449.708A + 9.036A2 - 139.813B + 3.095B2 - 7.699C - 0.164C2 + 13.116AB - 0.087AB2 - 0.248A2B + 3.781AC - 0.076A2C - 0.394BC. It showed an increase in γ-PGA yield with increasing L-glutamic acid and biotin, but a decrease with yeast extract.

Conclusions: Bacillus megaterium UP47 had a maximum γ-PGA yield of 54 g/L and 62 g/L, respectively, from the Plackett-Burman and Box-Benkhen design, thereby resulting in an appreciable increase in polymer yield after the optimization process with a 95% confidence level.

The history of "Polymers in Medicine" reflects not only the development of utilizing such materials in medicine and pharmaceutics, but also changes in Polish scientific journals - dissemination of results of scientific research and broader scientific activity always takes place in a specific linguistic and sociopolitical context. The paper presents a brief historical sketch of the journal, starting from the establishment of the information bulletin "Plastics in Medicine", through the 1st International Conference of the COMECON "Utilization of plastics in medicine", which took place in Warsaw in October 1969, and the founding of "Polymers in Medicine" in 1970-1971, until the present day. Subsequent editors-in-chief are introduced, along with transformations of the layout, and above all, the evolution of issues described in the published papers, which initially concerned chiefly polymer materials in general, orthotics and plastic medical equipment. The changing rhythm of publication of the journal is discussed on the background of economic transformations during the decline of Polish People's Republic and the early days of modern Poland. Languages in which articles and additional materials were published in "Polymers in Medicine" can be regarded as a symbol of changes in the globalizing world of science: between 1964 and 1986 four languages (Polish, English, Russian, and German), then three (without German) until 1997, then two (Russian also disappeared) and - since 2021 - one (English).

Coronavirus Disease 2019 (COVID-19) pandemic caused an increase in the demand for personal protective equipment (PPE) and disruptions in production chains, resulting in an acute shortage of PPE. A possible solution to this problem was additive manufacturing (AM) technology - allowing for a quick start of the production of PPE and potentially able to meet the demand until the production is restored. In addition, AM allows for the production of PPE prototypes with potentially greater comfort of use or degree of protection. In order to assess the production of PPE in AM during the COVID-19 pandemic, previously published articles in this field were analyzed. After analyzing abstracts and full texts, 30 original works were selected from the initially collected 487 articles. Based on the analyzed literature, it was found that there are not enough studies comparing traditional and AM PPE as well as not enough comparisons of the different types of AM PPE with each other. In many cases, researchers focused only on the subjective assessment of the comfort of using PPE, without assessing their effectiveness in preventing infections. Despite that, AM has a great potential to quickly produce lacking PPE. Respirators and shields made by AM were rated by the vast majority of users as comfortable to wear. Some of the respirators could be adapted to a specific user, by designing on the basis of a face scan or after warming up the finished print and modeling the shape.

Fucoidans represent the sulfated heteropolysaccharides that possess a wide range of important pharmacological properties. The properties of a fucoidan depend on several factors, including the molecular weight and the way of extraction. However, the selection of an optimal depolymerization method is necessary to enhance its therapeutic applications. Reducing the molecular weight of fucoidans will make it possible to use them in creating nanoparticles and nanocarriers for, among others, the targeted drug delivery. The molecular mass of the polymer can be changed by means of various methods of depolymerization. In this work, the possibility of application of ultrasonic destruction for decrease in the size of fucoidan molecules for the purpose of expansion of opportunities and spheres of their therapeutic application is considered. This is one of the simple and effective methods of depolymerization of fucoidan, which leads to a decrease in molecular weight without significant structural changes in macromolecules. In addition, methods and potential applications of the ultrasonic extraction of fucoidan from seaweed and the possibilities of their combination are discussed, as well as other physical or chemical methods of extraction.

Wound infection may occur in acute and chronic wounds, wounds resulting from surgery or traffic accidents, and burns. Regardless of the extent and cause of the wound, prompt treatment is essential in reducing the patient's pain and limiting the spread of contamination. Improper wound care and associated chronic diseases may hinder the therapeutic success. Bacterial cellulose (BC) is highly biocompatible and has no cytotoxic effect on cells engaged in wound healing, such as fibroblasts and keratinocytes. Its high hydration level guarantees the maintenance of a moist wound environment. High mechanical strength, flexibility and resistance to damage make BC a promising material for dressings. Unfortunately, it does not display an inhibitory effect on bacterial growth. Introducing antimicrobial agents into the structure of BC has been a subject of many studies. This paper aims to present the latest reports on the possibility of the absorption of bacteriostatic and bactericidal agents in BC, such as metal particles, essential oils, antibiotics, antiseptics, and wound irrigation solutions. Moreover, the modifications in BC culture and post-production treatments in order to improve its physical properties are discussed.

Background: Microbial pathogens, mainly bacteria, are a major cause of food spoilage resulting in several foodborne diseases. Food spoilage can be prevented by the application of chemical preservatives in the food industry but such process has harmful effects on human health and causes the introduction of chemicals in several food chains, leading to toxicity and long-term complications. Due to such adverse effects, the need to find natural preservatives that are safer to use, effective and less complicated is increasing.

Objectives: This study is based on plant extracts that play a major role in microbicidal action (the use of natural preservatives is preferred over chemical ones). Antimicrobial action of different plant extracts was assessed using Staphylococcus aureus and Escherichia coli as experimental bacterial strains.

Material and methods: Ethanolic extracts of different plants like Punica granatum, Acacia catechu and Phyllanthus emblica were highly effective against the both analyzed bacterial strains at a dosage of 10 mg/mL, while the extracts of Ocimum bacilicum and Quercus infectoria were effective only against S. aureus and E. coli, respectively.

Results: Punica granatum and Phyllanthus emblica extracts were found to be the most effective and exhibited bacteriostatic and bactericidal activities against the highly infectious strains of pathogenic bacteria causing food spoilage, with minimum inhibitory concentration (MIC) of 2.5 mg/mL and minimum bactericidal concentration (MBC) of 5 mg/mL.

Conclusions: The plant extracts used in the study were highly effective in reducing bacterial contamination and can be used as an alternative to chemical preservatives to avoid and control foodborne diseases and for preservation of food with no health-related hazards caused by chemicals.

Background: Pre-gelatinization is one of the most common physical methods of starch modification, which involves heating to bring about significant changes in the nature of starch, such as high swelling, loss of crystallinity, solubility in cold water, and improved pasting.

Objectives: To evaluate the structural and physicochemical properties of starch from Neorautanenia mitis tubers, and determine the effect of pre-gelatinization on the functional properties of this starch.

Material and methods: Properties of the pre-gelatinized starch (NMPS), such as flow, swelling power, hydration capacity, pH, morphology, Fourier-infrared spectroscopy (FTIR), differential scanning calorimetry, and pasting characteristics, were compared with those of the native starch (NMNS).

Results: Pre-gelatinized starch had good flow with the angle of repose at 33.69°. Carr's index was 10.90% and 7.50%, and the Hausner ratio was 1.12 and 1.05 for NMNS and NMPS, respectively. Both starches had neutral to near-neutral pH (7.00 and 6.04, respectively). The hydration capacity of NMPS (59.00%) was about 2 times higher than that of NMNS (25.80%), while the swelling power of NMPS between 40°C and 60°C was higher than that of NMNS, and maximum swelling for both starches was observed at 80°C. Morphology showed that NMNS granules were discrete, smooth and spherical, while those of NMPS were aggregated, with rough surfaces. The FTIR spectra of both starches showed identical absorption peaks but the enthalpy of gelatinization differed for both starches. The pasting properties also varied significantly among the starch samples. Native starch had better peak viscosity, breakdown viscosity and pasting temperature, while NMPS presented better trough viscosity, final viscosity, setback viscosity, and pasting time.

Conclusions: The results showed that pre-gelatinized starch from N. mitis tubers possesses high swelling and hydration abilities and significant pasting properties, and may be used as a disintegrant in solid dosage formulations and in products requiring low viscosities and bond strength.

Background: The pH of the skin surface is usually between 5.4 and 5.9 and functions as a barrier against bacteria and fungi; thus, the composition of the topically applied drug form may be of high importance for proper medication.

Objectives: To evaluate the influence of the measurement conditions in aqueous solutions of ointments, creams, and gels, which include polymeric components, on the pH and conductivity results.

Material and methods: The pH and electrolytic conductivity of aqueous dispersions of commercially available ointments, creams and gels were tested and compared to reference vehicles.

Results: The results of the dilution method measurements of the pH and electrolytic conductivity of the ointment preparations are highly diverse, ranging from 5.88 to 6.27, whereas the reference pH for Unguentum simplex was between 5.40 and 5.43. Furthermore, the measurements of the pH and electrolytic conductivity with the dilution method for creams did not provide repeatable results with a small sample size, and the pH of commercial preparations was in the range between 5.79 and 6.37, compared to the reference pH of 5.23-5.46. However, the dilution method for measurements of the pH and electrolytic conductivity was suitable for hydrogel preparations and the obtained results were repeatable in the range of 6.11-6.90, while the reference preparations were in the range of 5.19-5.62.

Conclusions: Evaluation methods of the electrolytic conductivity and pH of the preparations applied on the skin should be further evaluated; however, the pH of the commercial preparation seems to differ from the physiological skin pH, which covers the range of reference preparations.