Polimery w medycynie最新文献

Background: Solubility is a fundamental physicochemical property of active pharmaceutical ingredients. The optimization of a dissolution medium aims not only to increase solubility and other aspects are to be included such as environmental impact, toxicity degree, availability, and costs. Obtaining comprehensive solubility characteristics of chemical compounds is a non-trivial and demanding process. Therefore, support from theoretical approaches is of practical importance.

Objectives: This study aims to examine the accuracy of the reference solubility approach in the case of sulfanilamide dissolution in a variety of binary solvents. This pharmaceutically active substance has been extensively studied, and a substantial amount of solubility data is available. Unfortunately, using this set of data directly for theoretical modeling is impeded by noticeable inconsistencies in the published solubility data. Hence, this aspect is addressed by data curation using theoretical and experimental confirmations.

Material and methods: In the experimental part of our study, the popular shake-flask method combined with ultraviolet (UV) spectrophotometric measurements was applied for solubility determination. The computational phase utilized the conductor-like screening model for real solvents (COSMO-RS) approach.

Results: The analysis of the results of solubility calculations for sulfonamide in binary solvents revealed abnormally high error values for acetone-ethyl acetate mixtures, which were further confirmed with experimental measurements. Additional confirmation was obtained by extending the solubility measurements to a series of homologous acetate esters.

Conclusions: Our study addresses the crucial issue of coherence of solubility data used for many theoretical inquiries, including parameter fitting of semi-empirical models, in-depth thermodynamic interpretations and application of machine learning protocols. The effectiveness of the proposed methodology for dataset curation was demonstrated for sulfanilamide solubility in binary mixtures. This approach enabled not only the formulation of a consistent dataset of sulfanilamide solubility binary solvent mixtures, but also its implementation as a qualitative tool guiding rationale solvent selection for experimental solubility screening.

The eye is the most accessible site for topical drug delivery. Drug's ocular bioavailability is quite low when administered topically as eye drops. Viscosity enhancers are used to increase ocular bioavailability by extending the precorneal residence time of the drug at the ocular site. Cellulose, polyalcohol and polyacrylic acid are examples of hydrophilic viscosity enhancers. The addition of viscosity modifiers increases the amount of time the drug is in contact with the ocular surface. Several polysaccharides have been studied as excipients and viscosity boosters for ocular formulations, including cellulose derivatives such as chitosan (CS), xyloglucan and arabinogalactan (methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose (HPMC), and sodium carboxymethylcellulose). Viscosity-increasing substances reduce the surface tension, extend the corneal contact time, slow the drainage, and improve the bioavailability. Chitosan is a viscosity enhancer that was originally thought to open tight junction barrier cells in the epithelium. Chitosan thickens the medication solution and allows it to penetrate deeper. Alginate is an anionic polymer with carboxyl end groups that has the highest mucoadhesive strength and is used to improve penetration. Carboxymethylcellulose (CMC), a polysaccharide with a high molecular weight, is one of the most common viscous polymers used in artificial tears to achieve their longer ocular surface residence period. Hyaluronic acid (HA) is biocompatible and biodegradable in nature, and it is available in ocular sustained-release dose forms. A polymer known as xanthan gum is used to increase viscosity. At 0.2% concentration, carbomer forms a highly viscous gel.

Background: Microand nanoplastics pollution can cause substantial damage to ecosystems. Since scientists have focused mainly on their impact on aquatic environments, less attention has been paid to the accumulation of polymer particles in terrestrial organisms.

Objectives: We checked if submicron (<5 mm) polystyrene (PS) particles, which can accumulate in living organisms, lead to changes in the physicochemical properties of mammalian cell membranes.

Material and methods: The influence of submicron PS particles on the properties of rat-derived L6 myocytes and H9c2 cardiomyocytes was analyzed. Non-functionalized and amine-functionalized PS particles of 100 nm and 200 nm in diameter were used. The MTT assay was performed to evaluate the viability of the polymers-treated cells. The effect of short (6 h) and prolonged (48 h) incubation with different concentrations of PS particles on the cell's zeta (ζ) potential was examined with the electrophoretic light scattering technique (ELS). Polystyrene particles' physicochemical characteristics (size and stability) were performed using dynamic light scattering (DLS) and electrophoretic light scattering methods.

Results: The results show that submicron PS particles affect cell viability and cause changes in the physiochemical parameters of rat cell membranes. Differences were observed depending on the origin of the cells. We observed doseand time-dependent alterations in the studied parameters after submicron PS particle incubation in L6 myotubes and H9c2 cardiomyocytes.

Conclusions: The size and modification of PS particle surfaces determine the extent to which they affect the analyzed properties of rat cardiomyocytes and myocytes membranes.

In dentistry, fluoride compounds play a very important role in the development of teeth hard tissue. They have been modifying the development of the carious process for many years in accordance with the principles of minimally invasive therapy. Studies have confirmed their effectiveness in the prevention and treatment of carious lesions and erosion of deciduous and permanent teeth, as well as in the dentin hypersensitivity treatment. Typically, each varnish consists of 3 basic components, i.e., a resin usually in the form of mastic, shellac and/or rosin, an alcohol-based organic solvent (usually ethanol) and active agents. In the first-generation varnishes, the active agent is fluorine compounds, most often in the form of 5% NaF, while in second-generation varnishes, the composition is further enriched with calcium and phosphorus compounds in the form of CPP-ACP/CPP-ACPF, ACP, TCP, fTCP, CSPS, TMP, CXP, or CaGP. This influences the bioavailability of fluoride in the oral environment by increasing both its release from the product and its subsequent accumulation in enamel and plaque, promotes more efficient closure of dentinal tubules, and facilitates pH buffering in the oral cavity.

Over the years, exopolysaccharides (EPSs) have been utilized in various areas of research, including health, industry, environment, and agriculture, due to their flexible physical, chemical and structural properties that can be readily modified to suit desired purposes. Current research trends have shown that EPS production is dependent on numerous factors which can be combined to varying extent to optimize production yields. Although the majority of research is directed towards their industrial and medicinal uses, these chemical substances possess peculiar characteristics which are also exploited for biomedical research, where they are being used as drug delivery systems, some of which include their abundance in nature, biocompatibility, biodegradability, non-toxicity, and ability to efficiently encapsulate sensitive bioactive agents. However, despite the numerous beneficial prospects of microbial EPSs in drug delivery, there are limitations to the commercial production and industrial applications of these biopolymers. These limitations have inspired revolutionary research into the cost-effective production of safe EPSs polymers. In this review, we classify EPSs and discuss their methods of extraction and characterization. We also summarized current drug delivery applications and discussed limitations to extensive industrial commercialization of EPSs, while highlighting prospects for the utilization of microbial EPSs and implications for research.

Background: Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder with largely unknown pathogenesis and no effective cure. It is believed that several, not mutually exclusive mechanisms contribute to the pathogenesis and progression of this disease, including, among others, elevated oxidative stress, excitotoxicity, increased neuroinflammation, and protein aggregation. Receptor for advanced glycation end products (RAGE) is a part of immunoglobulin superfamily; it is believed to participate in ALS pathogenesis.

Objectives: Our previous studies on ALS demonstrated that RAGE is likely one of the key players in ALS, acting on its own and in tandem with its oxidative stress and pro-inflammatory ligands, such as advanced glycation end products (AGEs) or advanced oxidation protein products (AOPPs). In this study, based on our previous results, we aimed to establish blood levels of soluble RAGE, AGE and AOPP in ALS patients.

Material and methods: Forty-six coded and anonymized surplus plasma samples from ALS patients and non-neurological control were used in the study. The plasma levels of RAGE, AGE and AOPP were measured using enzyme-linked immunosorbent assay (ELISA) commercially available kits. Statistical evaluation of data was performed using one-way non-parametric analysis of variance (ANOVA) with Kruskal-Wallis post hoc test.

Results: Our results revealed a decline in soluble RAGE level, concurrent with an increase in the levels of AGEs and AOPPs in blood samples from ALS patients, signifying a loss of neuroprotective form of RAGE and a simultaneous increase in AGE and AOPP production and uptake at the early stage of the disease.

Conclusions: The results obtained from our study indicate that further longitudinal study of RAGE, AGE and AOPP levels would be beneficial, outlining the dynamics between RAGE and its ligand levels as the disease progresses, and making them valuable diagnostic tools and potential therapeutic targets.

Background: The adhesion of Pseudomonas aeruginosa to biotic and abiotic surfaces is responsible for the persistence and development of bacterial infection.

Objectives: To fill the gap in the knowledge regarding the relationship between rifaximin susceptibility and biofilm formation, and to investigate the effect of subinhibitory doses of rifaximin on the adhesion and biofilm formation.

Material and methods: A total of 10 isolates of P. aeruginosa were obtained from 110 urine samples of urinary tract infection (UTI) patients. Biofilm formation on polystyrene microtiter plates, minimum inhibitory concentrations (MICs) of rifaximin against the 10 isolates of P. aeruginosa (Pa1-Pa10), the effect of sub-MICs of rifaximin (0.5 × MIC, 0.25 × MIC, 0.125 × MIC, and 0.06 × MIC) on biofilm formation by the Pa4 isolate to polystyrene microtiter plates, and the adhesion to human epithelial cells (HECs) in vitro were evaluated.

Results: The MICs of rifaximin against 10 isolates ranged from 62.5 μg/mL to 1000 μg/mL. The Pa4 isolate produced the highest level of biofilm formation, while the MIC of Pa4 was 125 μg/mL. There was no correlation between bacterial susceptibility to rifaximin and biofilm formation (r: -0.016; p > 0.05). Sub-MIC doses of rifaximin significantly reduced the biofilm formation on abiotic surfaces, while only 0.5 × MIC, 0.25 × MIC and 0.12 × MIC of rifaximin reduced the adhesion to HECs significantly (p < 0.05) in a dose-dependent manner.

Conclusions: This pioneering study demonstrated the negative effect of sub-MIC doses of rifaximin on biofilm formation and adhesion to abiotic and biotic surfaces in vitro.

Tissue engineering has become one of the most studied medical fields and appears to be promising for the regeneration of injured bone tissues. Even though the bone has self-remodeling properties, bone regeneration may be required in some cases. Current research concerns materials employed to develop biological scaffolds with improved features as well as complex preparation techniques. Several attempts have been made to achieve compatible and osteoconductive materials with good mechanical strength in order to provide structural support. The application of biomaterials and mesenchymal stem cells (MSCs) is a promising prospect for bone regeneration. Recently, various cells have been utilized alone or in combination with biomaterials to accelerate bone repair in vivo. However, the question of what cell source is the best for use in bone engineering remains open. This review focuses on studies that evaluated bone regeneration using biomaterials with MSCs. Different types of biomaterials for scaffold processing, ranging from natural and synthetic polymers to hybrid composites, are presented. These constructs demonstrated an enhanced ability to regenerate the bone in vivo using animal models. Additionally, future perspectives in tissue engineering, such as the MSC secretome, that is the conditioned medium (CM), and the extracellular vesicles (EVs), are also described in this review. This new approach has already shown promising results for bone tissue regeneration in experimental models.

Background: Many substances are used to increase the viscosity of eye drops and reduce their surface tension. Their function is to prolong the persistence of the product on the surface of the eyeball and to increase the bioavailability of the pharmacologically active ingredient.

Objectives: To investigate the surface tension of substances added to the eye drops, with the main aim of modulating properties of the preparation.

Material and methods: Five substances contained in solutions proposed for the development of eye drops were studied: sodium hyaluronate macromolecular (H-Na W), sodium hyaluronate ultramolecular (H-Na UM), hyaluronic acid 4% (K-H), methylcellulose (MC), and polyacrylic acid (PA). The main method was to study the surface tension using the du Noüy ring tensiometer.

Results: The research presented in this paper shows the various effects of different eye drop ingredients on the surface tension of the solutions. The surface tension values of PA solutions are in the range of 48.89-56.03 mN/m, of MC in the range of 68.94-89.32 mN/m, of K-H 54.54-65.66 mN/m, of H-Na UM 67.18-70.97 mN/m, and of H-Na W 67.09-71.73 mN/m.

Conclusions: The use of different polymers affects the surface tension of model solutions proposed for use in ophthalmic preparations. Compounds containing carboxyl groups and anionic polymers have a similar effect on reducing the surface tension of the solution as classical surfactant compounds.

The introduction of tablet dosage forms has brought a revolution in the pharmaceutical drug delivery system. Different forms of tablets have been developed based on the target site, the onset of action, and therapeutic drug delivery methods. Fast-disintegrating tablets (FDTs) are the most promising pharmaceutical dosage form, especially for pediatric and geriatric patients having difficulty swallowing. The key feature of FDTs is quick drug release soon after their administration through the oral cavity. With innovations in the formulation of FDTs, the demand for excipients with better functionalities, particularly in terms of flow and compression characteristics, has increased. Co-processed excipients are a mixture of 2 or more conventional excipients that provides significant benefits over the individual excipients while minimizing their shortcomings. Such multifunctional co-processed excipients minimize the number of excipients that are to be incorporated into tablets during the manufacturing process. The present review discusses FTDs formulated from co-processed excipients, their manufacturing techniques, and the latest research, patents and commercially available co-processed FDTs.