Polimery w medycynie最新文献

Background: Ethylene oxide (EO) sterilization is the most used sterilization method for disposable medical devices. Its popularity is based on the fact that it can be executed on industrial scale on full pallets of packed products and the fact that many materials are compatible with this sterilization technique.

Objectives: This article describes an introduction to EO as a sterilization technique and further studies on the compatibility of medical grade plastics with EO sterilization.

Material and methods: Fourteen different healthcare polymer grades have been exposed to EO. This includes frequently used polyethylenes, polypropylenes, polyesters, and polycarbonates. Their mechanical and optical properties before and after exposure with EO were determined.

Results: After both the statistical analysis and a comparison with the accuracy of the measurement system, it can be concluded that all tested polymers retained their mechanical properties as measured by tensile and Izod impact testing after 1 sterilization cycle. Optical measurements showed that only 2 of the polymer grades had a minor discoloration, while all other materials had a very limited color change.

Conclusions: It has been shown that all families of plastics typically used in disposable medical products can be sterilized with EO without significant change in properties as determined on standardized test specimen.

Background: Dental sealants are used to caulk fissures and pits in order to prevent caries development both in deciduous and permanent dentition. Loss of sealant integrity leads to the formation of marginal gaps, consequently increasing the risk of caries.

Objectives: This study aimed to compare the physicochemical and clinically relevant properties of 3 commercially available resin-based pit and fissure sealants: Arkona Fissure Sealant (AFS; Arkona, Nasutów, Poland), Flow-Color (FC; Arkona, Nasutów, Poland) and Flow-It ALC (FIA; Pentron, Orange, USA).

Material and methods: After polymerization in dedicated molds, the materials were characterized using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), surface free energy (SFE) measurements and micromechanical testing to evaluate structural and mechanical properties. Scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS) was employed to visualize sample morphology and determine elemental composition. An in vitro fluoride release study was conducted in artificial saliva at varying pH values (4.5, 5.5, 7.0, 7.5), with deionized water as a reference. Measurements were recorded at 1, 3, 24, 48, 72, and 96 h, and then weekly for up to 7 weeks.

Results: AFS exhibited the highest values of SFE (38.4 mJ/m2), Vickers hardness (51.93 HV) and indentation modulus (11.93 kN/mm2). All sealants demonstrated cumulative fluoride release over the incubation period, with the highest release observed for AFS in artificial saliva at pH = 7.5 (0.772 ppm). FTIR spectra of all materials confirmed the presence of polymer backbones as declared by the manufacturers.

Conclusions: Presented findings provide insight into material-dependent properties influencing adhesion, mechanical performance and ion release of resin-based dental sealants. Among the tested materials, AFS exhibited the most favorable overall profile, combining high filler content, optimized particle architecture, superior mechanical strength, elevated surface energy, and sustained fluoride release, which together support robust adhesion, resistance to occlusal forces and effective caries prevention.

Due to physiological and anatomical barriers, optometrists and drug delivery specialists have long faced challenges in administering medications to the eyes. These ocular barriers - both permanent and temporary - limit the entry of foreign substances and reduce the effective absorption of therapeutic agents. Polymeric nanoparticles (NPs) provide advantages such as selective tissue targeting, improved drug bioavailability, stability, and controlled drug release. Their ability to overcome barriers like the precorneal film, cornea and intra-retinal regions depends on properties such as interfacial ligands, mucoadhesion, hydrophobicity, particle size, and surface charge. Careful design tailored to specific ocular tissues and diseases is essential. This study aims to explore the potential applications of polymeric NPs across various pharmaceutical categories in the treatment of ocular conditions.

Background: The polymer matrix of Klebsiella pneumoniae biofilm contributes to its resistance to a broad spectrum of antibiotics and poses a significant public health threat.

Objectives: The present study aims to use hydrogen peroxide (H2O2) sub-minimum inhibitory concentrations (sub-MICs) to improve cefotaxime efficiency against cefotaxime-resistant K. pneumoniae (CRKP) by disrupting the biofilm polymer matrix. Objectives. The present study aims to determine whether sub-MICs of hydrogen peroxide (H2O2) can enhance the efficacy of cefotaxime against CRKP by disrupting the biofilm polymer matrix.

Material and methods: Klebsiella pneumoniae was isolated from 140 burn wound samples. The effect of cefotaxime and sub-MICs of H2O2 on biofilm formation by pretreated K. pneumoniae was evaluated. A scanning electron microscope (SEM) was used to examine the effect of H2O2 sub-MICs on the biofilm matrix. The synergistic effect of H2O2 sub-MICs on the susceptibility of CRKP to cefotaxime and on the structure of the biofilm polymer matrix was also assessed.

Results: A moderately high incidence of wound infections caused by CRKP was observed. A statistically significant negative correlation was found between biofilm formation and bacterial susceptibility to cefotaxime (r = -0.501, p = 0.024). Treatment with various sub-MICs of H2O2 and cefotaxime reduced biofilm formation on polystyrene surfaces by the K. pneumoniae Kp10 isolate. Specifically, exposure to H2O2 at 1/8 MIC induced the formation of pores and channels within the biofilm matrix, resulting in a looser biofilm structure. A synergistic effect (fractional inhibitory concentration (FIC) index ≤ 0.5) was observed, where sub-MICs of H2O2 decreased the MIC of cefotaxime against Kp10 from 1,000 μg/mL to 250 μg/mL at ½ and ¼ MIC of H2O2, and produced a strong additive effect with a reduction to 500 μg/mL at other sub-MICs. The combination of H2O2 sub-MICs and cefotaxime was more effective in reducing biofilm formation than either agent used alone.

Conclusions: Sub-minimum inhibitory concentrations of H2O2 exhibited synergistic to strongly additive effects in enhancing the antibacterial activity of cefotaxime against CRKP and in reducing biofilm formation by the K. pneumoniae Kp10 isolate. This effect appears to be mediated by disruption of the biofilm polymer matrix, which may contribute to improved infection control.

For several decades, conventional treatments for chronic and degenerative diseases have been constrained by technological limitations, particularly those related to the physicochemical properties, stability and bioavailability of therapeutic molecules, as well as the efficiency of their delivery systems. Medical polymers are widely used in drug delivery to enhance the solubility, stability and controlled release of therapeutic agents, and they can be engineered into nanoparticles (NPs) derived from either natural or synthetic materials. Toward the end of the 20th century, the use of plant viral capsids as supramolecular structures for the packaging and controlled release of therapeutic compounds emerged, introducing a versatile, sustainable and cost-effective strategy that has progressively gained scientific and clinical relevance. Capsid proteins (CPs) derived from plant viruses can act as nanocages for drug encapsulation and delivery, and they can be surface-modified or functionalized with a wide range of biomolecules, including peptides, carbohydrates, functional groups, proteins, and oligonucleotides, through either chemical conjugation or genetic engineering approaches. This review explores the historical development, current biomedical applications, inherent challenges, and future prospects of plant-derived virus-like particles (pVLPs).

Polymeric surfactants play an important role in the research and development of drugs applied topically to the skin and mucous membranes. Their versatile properties include the ability to lower surface tension, thereby favorably contributing to the energetic balance of the emulsification process during the preparation of various dosage forms. In addition, they offer important structural advantages that enhance the stability of the resulting pharmaceutical or cosmetic products through electrostatic repulsion and steric effects. The influence of viscosity and density should also be taken into account when polymeric surfactants are considered as additives, as these are crucial components of various drug formulations. Emulsions used in ointments and creams are among the most relevant dosage forms affected by surface and interfacial tension phenomena. However, other dosage forms also require the use of surfactants, which may belong to the group of polymeric compounds.

Background: Polymethyl methacrylate (PMMA) is widely used as a denture base material despite its limitations, which include low transverse strength, impact resistance, surface hardness, and relatively high-water solubility and sorption. To enhance its mechanical and physical properties, PMMA has been modified by incorporating various metal powder fillers, such as aluminum and copper - despite their tendency to cause discoloration. These modifications aim to improve the overall quality and durability of dental prostheses.

Objectives: To evaluate the influence of incorporating microform propolis powder (known for its antifungal and antimicrobial properties and its rich composition of functional groups) into acrylic denture base material, and to assess its effect on selected physical and mechanical properties of the material.

Material and methods: A total of 128 specimens were prepared to evaluate various mechanical properties. Four groups were tested: 1 control group containing acrylic resin without propolis, and 3 experimental groups with propolis powder added at concentrations of 1.0%, 2.0% and 3.0% by weight. Each group consisted of 8 specimens for each mechanical test. All specimens were cured using the conventional heat-curing method. The mechanical properties evaluated included transverse strength, impact strength, surface hardness, and surface roughness. The data were statistically analyzed using the IBM SPSS software.

Results: The group with 1.0% propolis addition showed the highest mean values in all tested mechanical properties: transverse strength (90.50 N/mm²), impact strength (10.45 kJ/m²) and surface hardness (84.39). These values were significantly higher than those of the control group, with statistical analysis revealing highly significant differences between groups (p < 0.05) using ANOVA. Regarding surface roughness, the 1.0% propolis group also recorded the lowest mean value (1.03 μm), compared to the control group (2.14 μm), with all experimental groups showing significantly reduced roughness.

Conclusions: The incorporation of 1.0% microform propolis powder into PMMA denture base material significantly improved its mechanical and surface properties. These promising results suggest that further studies are warranted - either to explore additional properties or to test different propolis concentrations, potentially combined with coupling agents such as silane to enhance bonding and performance.

Photodynamic therapy (PDT) remains a developing modality in cancer treatment. It is a minimally invasive approach that employs a photosensitizing drug, activated by light, to induce localized cytotoxic effects. Initially introduced in oncology, PDT has proven effective for cancers such as skin malignancies and head and neck tumors, while sparing surrounding healthy tissue. Beyond oncology, its use has expanded to dermatology, ophthalmology and dentistry, and it shows promise in the management of chronic inflammatory conditions, pediatric nephrology and emerging applications in cardiovascular and neurodegenerative diseases. Despite persistent challenges such as limited light penetration, advances in photosensitizers and integration with technologies including immunotherapy and polymeric nanocarriers underscore PDT's potential as a versatile tool in precision medicine. Recent studies suggest that PDT can also modulate the tumor microenvironment (TME) and stimulate anti-tumor immune responses, thereby enhancing its therapeutic impact. Consequently, it is increasingly being investigated in combination with other treatment modalities to overcome resistance and improve patient outcomes.

Background: Natural gums offer environmentally friendly, biodegradable and non-toxic alternatives to synthetic binders in pharmaceutical formulations. Cocoa pod gum (CPG), derived from cocoa pod husk (CPH), presents a sustainable and underexplored source for pharmaceutical application.

Objectives: This study investigates the potential of CPG as a natural binder in metronidazole tablet formulations, evaluating its physicochemical and compressional properties, mechanical strength, drug release behavior, and compatibility with the active pharmaceutical ingredient.

Material and methods: The CPG was extracted from CPH and characterized alongside xanthan gum (XNG), a standard natural binder. Physicochemical analyses included pH, flow properties, viscosity, particle size, crystallinity, and thermal behavior. Compaction behavior was assessed using Heckel and Kawakita equations. Metronidazole tablets were formulated with varying concentrations (10-20% w/w) of both gums and evaluated for hardness, friability, disintegration time, and in vitro drug release. Compatibility was examined using Fourier transform infrared spectroscopy (FTIR).

Results: Cocoa pod gum demonstrated better flow properties and swelling capacity, while XNG showed higher viscosity and plastic deformation, yield pressure (Py) and PK values. Tablets formulated with XNG had greater hardness and slower disintegration, resulting in more delayed drug release. Cocoa pod gum-based tablets disintegrated faster and showed rapid drug release, making them more suitable for immediate release formulations. Fourier transform infrared spectroscopy confirmed no drug-excipient incompatibilities.

Conclusions: Cocoa pod gum exhibits promising binder properties comparable to XNG and may serve as a cost-effective, sustainable and biocompatible alternative to conventional excipients in tablet formulations.

This review comprehensively describes the applications of biomaterials in gynecology, focusing on their role in treating gynecological disorders, reconstructive procedures and minimally invasive surgeries. It highlights the latest advancements, such as biocompatibility, innovative implants and biodegradable materials. This article also provides information about biomaterials used for vaginal and pelvic wall reconstruction in pelvic organ prolapse patients, as well as its use in minimally invasive surgical procedures and infertility treatment (including assisted reproductive technologies (ART)). The application of biomaterials in gynecological oncology is also discussed, as biomaterials - particularly those incorporating nanotechnology - enable selective drug delivery and targeted cancer therapy. We highlight the current clinical challenges and unmet needs while offering a forward-looking perspective on the potential of biomaterials in advancing regenerative medicine, personalized treatments and improving outcomes for women's health. We aim to provide some directions for future research and the development of novel biomaterials that can improve gynecological care.