FEATURES OF OBTAINING GELS BASED ON AGAR-AGAR FOR COSMETOLOGY AND MEDICINE WITH ANTIBACTERIAL PROPERTIES

In the modern world, special attention is paid to materials with controlled characteristics. In this aspect, polymers and materials based on them have a number of specific properties for effective use in medicine and cosmetology. Humic substances satisfy most of these features, so their use is very important. The study of the features of the processes of gelation in polymer systems such as agar-agar, which has rather universal properties, makes it possible to use it as a basis for gels and polymer carriers, as well as in the processes of obtaining medical and cosmetic materials with different properties, which can be important in solving a number of topical issues. In particular, these are lightweight and cheap to manufacture antiseptic gels, dressings on wounds with absorption and protective properties, all kinds of cosmetics. In the article, a study was carried out to study the processes of gelation and the features of the rheological properties of hydrogels based on agar-agar in order to obtain modern hydrogels with an antibacterial effect. It was found that the introduction of humic acids into the composition of polymer hydrogels slows down the processes of structure formation, which leads to a decrease in the viscosity of all the studied compositions. Also, a decrease in the melting temperature of hydrogel jellies with an increase in the content of humic acids in them indicates a reduced level of gelation, which also leads to an increase in the time of loss of stickiness of polymer hydrogels. It has been shown that humic acids in polymer hydrogels have high antibacterial activity and almost completely stop the processes of mold formation in them. It was found that the most effective from the point of view of obtaining hydrogels with an antibacterial effect are agar-agar compositions with a humic acid content of 15 %. Thus, cosmetic polymer hydrogels with an antibacterial effect have been developed, which can be used in the treatment of hands, face and other areas of the skin that are open and contact for humans to combat coronavirus bacteria.

Construction of a Novel Doxorubicin Nanomedicine Using Bindarit as a Carrier: A Multiscale Computer Simulation-Assisted Design-Based Study

Nanomedicines typically use polymeric materials or liposomes as carriers. This provides targeting advantages but may lead to a series of defects, such as low drug loading, high risk in terms of safety, and high production costs. Herein, we report a computer simulation-assisted designing method for the construction of a novel doxorubicin (DOX) nanomedicine without any polymer carriers. We used a small molecular drug, bindarit (BIN), as a carrier of DOX to provide synergistic antitumor effects. First, the intermolecular forces between DOX and BIN were calculated for evaluating the interaction and potential conformation of the DOX/BIN complex. Then, the potential assembly ability of the DOX/BIN complex was predicated here by using dissipative particle dynamic stimulation. These computational simulation results suggested that BIN could form an amphiphilic complex with DOX through π–π stacking, hydrogen bonding, and electrostatic interaction and then self-assemble to nanoaggregates at the mesoscopic scale. Under the computational guidance, doxorubicin/bindarit nanoparticles (DOX/BIN NPs) in a spherical morphology were successfully prepared, and these NPs possess the original cytotoxic activity of DOX. Thus, this multiscale computer simulation-assisted design strategy can serve as an effective approach to develop nanomedicines using small molecules as a carrier.

Polymerization of Styrene in the Presence of Polybutadiene as a Stabilizer

The problem of synthesis of polymer suspensions with a narrow particle size distribution is relevant, since the field of their practical application is extremely wide. They are used as calibration standards in electron and optical microscopy and light scattering, for determining the pore size of filters and biological membranes, as model colloids, for studying the kinetics and mechanism of film formation from latex, as well as as polymer carriers of biological ligands in immunochemical studies [1].

Synthesis of new immobilized N-chloro-sulfonamides and release of active chlorine from them

A method has been developed for the synthesis of granular polymeric materials with immobilized N-chloro-sulfonamide groups. Commercially available resin polymers widely applied for the preparation of ion exchangers have been used as polymer carriers. The elaborated technological conditions make it possible to modify these resins with a high conversion degree, without deteriorating the strength characteristics, and with the possibility of regulating the concentration of active chlorine over a wide range (up to 11 % w/w). The structure of the synthesized polymers was confirmed by IR spectroscopy data. To determine the concentration of functional groups, a special method of iodometric titration has been developed. The processes of emission of active chlorine from synthesized polymers into aqueous solutions have been studied. It has been shown that this process significantly depends on the composition of the solution: no release of active chlorine into distilled water is observed, and when using tap water, its concentration is reached 5–8 mg/dm3 and remains up to 30 days when the granules are in water. The processes of activation of active chlorine emission by compounds of amine nature have been studied, the corresponding kinetic curves of the dependence between change in the concentration of active chlorine in solution and the used activator are presented. It has been found that the nature of the used activator strongly affects, among other things, the stability of the obtained chlorine-active solutions. Taurine and sulfamic acid are found to be the optimal activators for obtaining stable solutions of active chlorine of high concentration. The composition of the N-chloro-taurin solution obtained in this way has been additionally analyzed by UV spectroscopy. Thus, the synthesized polymers make it possible to quickly in situ obtain high-purity solutions of active chlorine without the use of special electrochemical equipment. The polymers themselves are compact, stable, and can be repeatedly regenerated

Reactive Oxygen Species Responsive Polymers for Drug Delivery Systems

Reactive oxygen species (ROS) play an essential role in regulating various physiological functions of living organisms; however, as the concentration of ROS increases in the area of a lesion, this may undermine cellular homeostasis, leading to a series of diseases. Using cell-product species as triggers for targeted regulation of polymer structures and activity represents a promising approach for the treatment. ROS-responsive polymer carriers allow the targeted delivery of drugs, reduce toxicity and side effects on normal cells, and control the release of drugs, which are all advantages compared with traditional small-molecule chemotherapy agents. These formulations have attracted great interest due to their potential applications in biomedicine. In this review, recent progresses on ROS responsive polymer carriers are summarized, with a focus on the chemical mechanism of ROS-responsive polymers and the design of molecular structures for targeted drug delivery and controlled drug release. Meanwhile, we discuss the challenges and future prospects of its applications.

Synthetic, Natural, and Semisynthetic Polymer Carriers for Controlled Nitric Oxide Release in Dermal Applications: A Review

Nitric oxide (NO•) is a free radical gas, produced in the human body to regulate physiological processes, such as inflammatory and immune responses. It is required for skin health; therefore, a lack of NO• is known to cause or worsen skin conditions related to three biomedical applications— infection treatment, injury healing, and blood circulation. Therefore, research on its topical release has been increasing for the last two decades. The storage and delivery of nitric oxide in physiological conditions to compensate for its deficiency is achieved through pharmacological compounds called NO-donors. These are further incorporated into scaffolds to enhance therapeutic treatment. A wide range of polymeric scaffolds has been developed and tested for this purpose. Hence, this review aims to give a detailed overview of the natural, synthetic, and semisynthetic polymeric matrices that have been evaluated for antimicrobial, wound healing, and circulatory dermal applications. These matrices have already set a solid foundation in nitric oxide release and their future perspective is headed toward an enhanced controlled release by novel functionalized semisynthetic polymer carriers and co-delivery synergetic platforms. Finally, further clinical tests on patients with the targeted condition will hopefully enable the eventual commercialization of these systems.