Polimery w medycynie最新文献

Microencapsulation is a technology for encapsulating particles in a coating designed to isolate the core substance from external conditions, including oxidation, UV radiation or humidity. Microcapsules reach dimensions of up to 5,000 μm. In the pharmaceutical industry, they are used for the controlled release of active substances, masking their taste, odor or gastrointestinal irritation, and can also reduce the toxicity of some medicinal substances. In the food production industry, the encapsulation process applies to sweeteners, enzymes, microorganisms, vitamins and minerals, flavors, or colors. The production of microcapsules is based on the use of their physical properties such as amphiphilicity, partition coefficient and melting point, while their formation of microcapsules is mainly carried out using physical methods such as coacervation, spray drying, cooling and coating, agglomeration, suspension crosslinking, solvent evaporation, and extrusion, as well as chemical methods: interfacial polymerization and in situ polymerization. Although traditional methods are still used to produce microcapsules, contemporary methods employing the latest technology are also emerging. One such method is encapsulation in microcylinders produced with a 3D printer.

Background: Hydrogels, containing a large amount of water and exhibiting high biocompatibility, can improve the rheological properties of formulations and adhere well to the application site. In Poland, only 1 hydrogel substrate is currently approved for pharmaceutical compounding: Celugel, based on hydroxyethyl cellulose (HEC).

Objectives: The aim of this study was to investigate how the variation in the raw material composition of Celugel-based hydrogels affects their osmotic pressure values and selected rheological properties.

Material and methods: Ten gel formulations were prepared using a commercial Celugel as the base, with varying percentages of added water, alongside a consistent 5 wt% addition of sucrose. The research methods employed include osmotic pressure, dynamic viscosity, pH measurement, and surface tension using the du Noüy ring tensiometer.

Results: The composition of the formulation has a significant impact on the osmotic pressure. Nearly all of the hydrogels exhibited hyperosmotic characteristics relative to living tissues, with measured osmotic pressure values ranging from 160 mOsm/kg H2O to 1,480 mOsm/kg H2O. As anticipated, the viscosity of the formulations increased proportionally with the growing concentration of Celugel ranging from 2.19 mPa·s to 562.87 mPa·s.

Conclusion: The composition of Celugel significantly influences its rheological properties and osmotic pressure values, with the concentration of the gelling agent being the most impactful factor. The results suggest that Celugel is suitable for use in formulations intended for nasal administration.

Background: One of the key challenges in tissue engineering area is the creation of biocompatible scaffolds that support cell growth and mimic the structural and mechanical properties of native tissues. Among various materials used for scaffold fabrication, composite materials based on biodegradable polymers reinforced with bioactive inorganic fillers have attracted significant attention due to their properties. One of the important problems with the preparation of composite electrospun fibers is the low filler content in the fiber.

Objectives: This study aims to select the best composition for electrospun polymer fibers in terms of potential application in tissue engineering. The effect of the viscosity of polymer solution/dispersion and filler content on the structure and properties of the fibers was determined. Morphology and filler content were compared.

Material and methods: Series of electrospun composite fibers were fabricated from poly(ĺ-caprolactone) (PCL), poly(L-lactic acid) (PLLA) and hydroxyapatite (HAP), containing from 10 wt% to 40 wt% HAP. The properties of the resulting composites were studied using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and viscosimetry measurements.

Results: The addition of HAP to the polymer solution caused a significant increase in viscosity, but the results showed that it is possible to obtain composite electrospun fibers even with 40 wt% filler content. Scanning electron microscopy analysis shows randomly oriented electrospun fibers with an average diameter in the range of 3.8-8.5 ěm for solution and dispersion with high viscosity (1,210-2,000 mPa·s) and significantly larger diameters (approx. 12 ěm) for the PCL solution (326 mPa·s).

Conclusion: It is possible to transform the composite dispersion from biopolymers and HAP into nonwoven fabrics at up to 40 wt% filler content. Due to their unique properties, such materials are promising for application in tissue engineering.

Background: Acne vulgaris is a common inflammatory skin condition affecting almost 85% of the adolescent and young adult population. The etiopathogenesis of this dermatosis involves an imbalance in the skin microbiome, leading to inflammation of both the skin and hair follicles.

Objectives: The aim of this study was to develop topical anti-acne formulations with increased therapeutic efficacy and reduced risk of developing antibiotic resistance. Six hydrogel formulations containing azelaic acid or its derivative, azeloglycine, in combination with tetracycline hydrochloride were prepared as part of the study.

Material and methods: The investigated formulations were prepared using an Eprus U500 pharmaceutical mixer and the pH was determined using an ERH-11S electrode designed for dense substances and a CPC-505 Elmetron pH-meter. The formulations were analyzed for tetracycline stability in the presence of additional active ingredients and varying pH over a period of 35 days using high-performance liquid chromatography (HPLC). In addition, the effects of azeloglycine and azelaic acid on the viscosity of the prepared formulations were evaluated using a Brookfield DV2T rotational viscometer.

Results: Chromatographic analysis showed significant stability of tetracycline in most formulations, with azeloglycine-containing formulations showing less degradation of the antibiotic than azelaic acid-containing preparations. In addition, azeloglycine-containing gels exhibited more favorable rheological properties, which may facilitate better application and be more beneficial to patients.

Conclusion: The results suggest that formulations containing azeloglycine and tetracycline may be a promising strategy for acne therapy, offering increased tetracycline stability and an optimal rheological profile, which may result in prolonged therapeutic effect and more effective drug delivery to the skin.

Developing the analytical procedure requires estimating what independent variables will be tested and at what levels. There are statistical models that enable the optimization of the process. They involve statistical analysis, which indicates the crucial factors for the process and the potential interactions between the analyzed variables. Analysis of variance (ANOVA) is applied in the evaluation of the significance of the independent variables and their interactions. The most commonly used chemometric models are Box-Behnken Design, Central Composite Design and Doehlert Design, which are second-order fractional models. The alternative may be the artificial neural networks (ANN), whose structure is based on the connection of neurons in the human brain. They consist of the input, hidden and output layer. In such analysis, the activation functions must be defined. Both approaches might be useful in planning the analytical procedure, as well as in predicting the response prior to performance the measurements. The proposed procedures may be applied for polymeric systems.

Globally, skin cancer is the predominant form of cancer, with melanoma identified as its most deadly variant. Projections suggest a surge exceeding 50% in melanoma occurrences by 2040, underscoring the urgency for preventive interventions. Sulforaphane (SFN), a compound found in cruciferous vegetables, is recognized for its cancer-preventive capabilities, particularly against skin cancer. This study employed a rigorous systematic review of various databases, adhering to predefined inclusion criteria for study selection. Data extraction was conducted using a uniform template, and the quality of the included studies was evaluated through the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) risk of bias tool, specifically designed for animal research. The review encompasses studies published in English from 2000 to 2023, culminating in the inclusion of 9 pertinent studies. The findings highlight SFN's capacity to act as a protective agent in preventing skin cancer in animal models. It demonstrated efficacy in curbing skin tumorigenesis triggered by assorted carcinogens, reducing the onset of skin tumors and impeding the growth and spread of skin cancer cells. Furthermore, SFN showed preventive effects against UVB-induced skin carcinogenesis by obstructing the activator protein 1 signaling pathway. Based on evidence from animal-based research, SFN emerges as a promising chemopreventive substance against skin cancer. Nevertheless, determining its optimal dosage, application duration and method of administration for human subjects remains pending. If its effectiveness is substantiated, SFN could complement or offer an alternative to existing preventive measures against skin cancer.

Background: Dapsone (DAP) is an anti-inflammatory and antimicrobial active pharmaceutical ingredient used to treat, e.g., AIDS-related diseases. However, low solubility is a feature hampering its efficient use.

Objectives: First, deep eutectic solvents (DES) were used as solubilizing agents for DAP as an alternative to traditional solvents. Second, intermolecular interactions in the systems were described and quantified. Finally, the solubility prediction model, previously created using the machine learning protocol, was extended and improved using new data obtained for eutectic systems.

Material and methods: New DES were created by blending choline chloride (ChCl) with 6 selected polyols. The solubility of DAP in these solvents was measured spectrophotometrically. The impact of water dilution on the solubility curve was investigated. Experimental research was enriched with theoretical interpretations of intermolecular interactions, identifying the most probable pairs in the systems. Dapsone self-association and its ability to interact with components of the analyzed systems were considered. Thermodynamic characteristics of pairs were utilized as molecular descriptors in the machine learning process, predicting solubility in both traditional organic solvents and the newly designed DES.

Results: The newly formulated solvents demonstrated significantly higher efficiency compared to traditional organic solvents, and a small addition of water increased solubility, indicating its role as a co-solvent. The interpretation of the mechanism of DAP solubility highlighted the competitive nature of self-association and pair formation. Thermodynamic parameters characterizing affinity were instrumental in developing an efficient model for theoretical screening across diverse solvent classes. The study emphasized the necessity of retraining models when introducing new experimental data, as exemplified by enriching the model with data from DES.

Conclusions: The research showcased the efficacy of developing new DES for enhancing solubility and creating environmentally and pharmaceutically viable systems, using DAP as an example. Molecular interactions proved valuable in understanding solubility mechanisms and formulating predictive models through machine learning processes.

Background: One of the important formalisms of non-equilibrium thermodynamics is Peusner network thermodynamics. The description of the energy conversion in membrane processes, i.e., the conversion of the internal energy of the system into the dissipated energy and the free energy used for the work associated with the transport of solution components, allows us to describe the relationship between these energies and the thermodynamic forces acting in the membrane system.

Objectives: The aim of this study was to develop a procedure to transform the Kedem-Katchalsky equations for the transport of binary electrolytic solutions across a membrane into the Kedem-Katchalsky-Peusner equations based on Peusner network thermodynamics. The conversion of electrochemical energy to free energy in the membrane system was also determined.

Material and methods: The nanobiocellulose biomembranes (Biofill) were the subject of the study with experimentally determined transport parameters for aqueous NaCl solutions. The research method is the Kedem-Katchalsky-Peusner formalism for binary electrolyte solutions with introduced Peusner coefficients.

Results: The coefficients of the L version of the membrane transport equations and the Peusner coupling coefficients were derived as functions of NaCl concentration in the membrane. Based on these coefficients, the fluxes of internal energy of the system, energy dissipated to the surroundings and free energy related to the transport of electrolyte across the membrane were calculated and presented as functions of the osmotic and electric forces on the membrane.

Conclusions: The Peusner coefficients obtained from the transformations of the coefficients of the Kedem-Katchalsky formalism for the transport of electrolyte solutions through the Biofill membrane were used to calculate the coupling coefficients of the membrane processes and the dissipative energy flux. The dissipative energy flux takes the form of a quadratic form due to the thermodynamic forces on the membrane - second degree curves are obtained. Moreover, the dissipative energy flux as a function of thermodynamic forces allowed us to examine the energy conversion in transport processes in the membrane system.

Background: Today's growing demand for advanced and sustainable polyester materials is driven by an increasing awareness of the environmental impact of traditional materials, emphasizing the need for eco-friendly alternatives. Sustainability has become central in materials development, including the biomedical area, where biobased and environmentally friendly solutions are a rapidly growing field.

Objectives: This research aims to comprehensively evaluate a new enzymatically catalyzed furan-based copolymer, poly(decamethylene furanoate)-co-(dilinoleic furanoate) (PDF-DLF), with a 70-30 wt% hard-to-soft segment ratio. Then, its performance across medical applications is explored, with a particular focus on its potential as a nanofibrous scaffolding material.

Material and methods: PDF-DLF was synthesized from biobased monomers using Candida antarctica lipase B (CAL-B) as the biocatalyst. Material characterization included dynamic mechan‑ical thermal analysis (DMTA) to assess the mechanical behavior and thermal properties. Enzymatic degradation studies determined biodegradability, while cytotoxicity tests established in vitro biocompatibility. The copolymer was electrospun into nanofibers, with scanning electron microscopy (SEM) employed to analyze their morphology.

Results: PDF-DLF displays mechanical and thermal properties indicating high storage modulus and 2 main temperature transitions. Enzymatic degradation studies and cytotoxicity assessments confirm biodegradability and in vitro biocompatibility. Electrospinning successfully transformed the copolymer into nanofibers with diameters ranging from 500 nm to 700 nm.

Conclusions: This study significantly advances our understanding of sustainable polyesters with versatile processing capabilities. The successful electrospinning highlights its potential as a biodegradable scaffold for medical engineering, supported by biocompatibility and sufficient mechanical properties. It opens new opportunities for sustainable materials in critical biomedical industries, including tissue engineering.

Background: There is a lack of studies evaluating the toxicity of nitric oxide (NO) precursors in chitosan/L-arginine hydrogels and their topical administration. However, clarifying the characteristics of these elements is essential for their possible use in non-surgical techniques of tooth movement acceleration. Such characteristics include interaction with different cell types, metabolism and drug safety.

Objectives: This in vitro study aimed to assess the cytotoxicity of chitosan hydrogels on human HeLa cells using different concentrations of L-arginine.

Material and methods: The hydrogels were synthesized in a materials engineering laboratory, with a controlled environment, using 4 different L-arginine concentrations of 0%, 10%, 15%, and 20%. Once the hydrogels were prepared, their physical and chemical properties were characterized, and viability analysis was performed using 2 different methods, including a 48-h assay with Artemia salina nauplii and a 24-h cell culture with human HeLa cells followed by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) proliferation assay. Data analysis was performed using a Mann-Whitney U test to evaluate positive and negative controls in the cell culture, with a significance level of 0.01. A Wilcoxon paired test contrasted the 24-h compared to 48-h Artemia salina assays, with a Kruskal-Wallis and post hoc Dunn test used to compare groups using a significance level of 0.05.

Results: In the more viscous hydrogels, Artemia salina nauplii decreased drastically in 24 h, while the 15% and 20% hydrogels had no statistical differences from the negative control. The 10% and 20% hydrogels were statistically different from the negative control when comparing cell culture data.

Conclusions: Our findings suggest that chitosan/L-arginine hydrogels could be used in humans without toxic effects. However, more trials and tests are needed to evaluate tooth movement rate during orthodontic treatment.