Polimery w medycynie最新文献

Background: Neomycin is a natural aminoglycoside antibiotic produced by actinomycete Streptomyces fradiae. It exerts bacteriostatic and bactericidal activity against Gram-negative bacteria, certain Gram-positive bacteria and Mycobacterium tuberculosis. Neomycin inhibits the biosynthesis of bacterial proteins by impairing their life functions, leading to death of cells.

Objectives: To examine the effect of molecular weight of polylactide (PLA), the applied stabilizer as well as mixing speed used in the encapsulation process on the size of obtained spheres. Examination of the kinetics of neomycin release from the obtained PLA spheres and determination of the antimicrobial activity of the neomycin-containing spheres against selected strains of bacteria, yeast and fungi have also been necessary.

Material and methods: Polylactide (Mn 3000-40,000 g/mol) was obtained in-house. Other materials used in the study were as follows: L-lactic acid (PLLA; Mn 66,500 g/mol and 86,000 g/mol), polyvinyl alcohol (PVA) as a stabilizer of emulsion (Mw 30,000 g/mol, 130,000 g/mol; degree of hydrolysis 88%) as well as dichloromethane, p.a. and dimethyl sulfoxide (DMSO), p.a. as solvents. Distilled water was obtained in-house. Neomycin sulfate was used for encapsulation; phosphate (pH 7.2) and acetate (pH 4.5) buffers were used for the examination of the active pharmaceutical ingredient (API) dissolution profile. Antimicrobial activity was tested using commercial cell lines and the following media: Mueller-Hinton agar (MHA), Mueller-Hinton broth (MHB), yeast extract peptone dextrose (YPD), and potato dextrose agar (PDA).

Results: Neomycin-containing PLA spheres were obtained using an emulsion method. The average molecular weight of PLA, the average molecular weight of PVA and mixing speed on the size of obtained spheres were investigated. Furthermore, the profile of API dissolution from the spheres and antimicrobial activity of neomycin-containing spheres against certain strains of bacteria, yeast and fungi were determined.

Conclusions: We demonstrated that efficient encapsulation of neomycin requires spheres of a <200 mm diameter.

Poly(glycerol sebacate) (PGS) is an aliphatic polyester which attracted significant scientific attention in recent years due to its vast potential in biomedical applications with regard to tissue engineering. It has been presented in the literature in the form of 2D films, porous scaffolds or nonwovens, to name just a few. Moreover, various applications have been proposed as a component of composite materials or polymer blends. Its physicochemical properties can be significantly adjusted by means of synthesis and post-synthetic modifications, including cross-linking or chemical modification, such as copolymerization. Many scientists have discussed PGS as a new-generation polymer for biomedical applications. Its regenerative potential has been confirmed, in particular, in tissue engineering of soft tissues (including nerve, cartilage and cardiac tissues). Therefore, we must anticipate a growing importance of PGS in contemporary biomedical applications. This brief review aims to familiarize the readers with this relatively new polymeric material for tissue engineering applications.

Natural polymers have been commonly applied in medicine and pharmacy. Their primary function is to enhance drug delivery, tissue regeneration or wound healing, and diagnostics. Natural polymers appear promising for photodynamic protocols, including photodiagnosis (PDD) and photodynamic therapy (PDT). Currently, the most challenging issue with natural polymers is to appropriately select the most effective material regarding the type of cancer treated. The technological achievements enable functionalization of natural polymers by specific antibodies, or enhancement using fluorescent or quantum dot markers for diagnostic applications. This review will discuss the types and properties of natural polymers and available applications of PDD and PDT which seem to be promising in cancer treatment. Treatment of neoplastic diseases is still a challenge for both physicians and scientists, so the search for alternative methods of treatment and diagnosis based on natural materials is relevant.

Background: Plant-extract-reduced metal nanoparticles provide means of overcoming microbial resistance. Incorporating them into appropriate pharmaceutical formulations will enhance their portability and ease of administration.

Objectives: To synthesize silver nanoparticles using methanol extracts of the seeds of Blighia sapida as capping agents and formulating the products in antimicrobial films.

Material and methods: Phytochemical screening of the methanol extract of Blighia sapida K.D. Koenig (ackee) seeds was performed and its antioxidant properties were determined using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. The green synthesis of ackee seed extract silver nanoparticles (ASAgNPs) was accomplished with reacting 1 mM of aqueous silver nitrate (AgNO3) and the methanol extract in a flask; the bioreduction was performed at 37°C for 72 h. The resulting nanoparticles were lyophilized and characterized using UV-visible spectrophotometry, Fourier-transform infrared spectroscopy (FTIR) and photomicrography. The nanoparticles were further formulated into films using starch and carboxymethyl cellulose using the solvent evaporation method. The extract, biosynthesized nanoparticles and film formulations were screened for antimicrobial activity against several pathogens using the agar well diffusion method.

Results: The methanol seed extracts of the ackee fruit contained saponins, tannins, flavonoids, terpenoids, and anthraquinones. The extract exhibited significant antioxidant properties. The nanoparticles and film formulations had a broader range of activity against microbes than the plant extract, exhibiting significant activity against Escherichia coli ATCC 700728, Salmonella typhi ATCC 14028, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853. Activity was also observed with Candida krusei, C. albicans, and Penicillium sp. It is noteworthy that this last organism showed resistance to fluconazole.

Conclusions: Ackee seed extract silver nanoparticles exhibited a synergistic antimicrobial activity against several pathogens. Film formulations of the nanoparticles retained this antimicrobial activity and allowed the product to be presented in a consumer-ready form.

The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thickness, and is the most important layer for the transparency of cornea and refractive function critical for vision. Any significant damage to this layer may lead to corneal blindness. Corneal blindness refers to loss of vision or blindness caused by corneal diseases or damage, which is the 4th most common cause of blindness worldwide. Different approaches are used to treat these patients. Severe corneal damage is traditionally treated by transplantation of a donor cornea or implantation of an artificial cornea. Other alternative approaches, such as cell/stem cell therapy, drug/gene delivery and tissue engineering, are currently promising in the regeneration of damaged cornea. The aim of tissue engineering is to functionally repair and regenerate damaged cornea using scaffolds with or without cells and growth factors. Among the different types of scaffolds, polymer-based scaffolds have shown great potential for corneal stromal regeneration. In this paper, the most recent findings of corneal stromal tissue engineering are reviewed.

Viruses that are pathogenic to humans and livestock pose a serious epidemiological threat and challenge the world's population. The SARS-CoV-2/COVID-19 pandemic has made the world aware of the scale of the threat. The surfaces of various materials can be a source of viruses that remain temporarily contagious in the environment. Few polymers have antiviral effects that reduce infectivity or the presence of a virus in the human environment. Some of the effects are due to certain physical properties, e.g., high hydrophobicity. Other materials owe their antiviral activity to a modified physicochemical structure favoring the action on specific virus receptors or on their biochemistry. Current research areas include: gluten, polyvinylidene fluoride, polyimide, polylactic acid, graphene oxide, and polyurethane bound to copper oxide. The future belongs to multi-component mixtures or very thin multilayer systems. The rational direction of research work is the search for materials with a balanced specificity in relation to the most dangerous viruses and universality in relation to other viruses.

Background: Phyto-reduction using Senna alata methanol leaf extract for nanoparticle (NP) biosynthesis is of great importance for the production of value-added nanomaterial with antimicrobial potential.

Objectives: The aim of this study was to investigate the biosynthesis of zinc oxide nanoparticles (ZnONPs) using crude methanol leaf extract of S. alata (SaZnONPs), antimicrobial efficacy of this extract, optimization of its production parameters, and its application in cold cream formulation.

Material and methods: Phytosynthesized SaZnONPs were characterized using UV-Vis absorption spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), X-ray diffraction (XRD) analysis, and energy-dispersive X-ray (EDX) spectroscopy. The antimicrobial activity of SaZnONPs and the formulated cold cream was evaluated.

Results: The SaZnONPs surface plasmon resonance (SPR) was 400 nm. Functional groups such as alkenes, alkynes and alkyl aryl ether were present. The SEM image showed NPs 7.10 nm in size and with a needle-like shape. The TGA values show the formations of stable ZnONPs, while the DLS showed the particle diameter average of 89.7 nm and 855.4 nm with 0.595 polydispersity index. The EDX analysis confirmed the formation of pure ZnONPs, and the crystallinity was confirmed with XRD analysis. Twenty-four hours of incubation and production at pH13 was optimal for NPs synthesis. The SaZnONPs and the formulated cold cream have antimicrobial properties against some pathogenic bacteria and Pichia sp. (16.00 mm) and Trichophyton interdigitale (11.00 mm).

Conclusions: Senna alata was able to serve as a stabilizing and capping agent for SaZnONPs biosynthesis. The SaZnONPs had good antimicrobial potential and can be used in cold cream formulation.

Background: Co-processing starch with clay nanocomposite has been shown to yield a new class of materials, potentially with better properties than pristine starch, that could be used as directly compressible excipients in tablet formulations.

Objectives: In this study, starches from 3 botanical sources, i.e., millet starch from Pennistum glaucum (L) RBr grains, sorghum starch from Sorghum bicolor L. Moench grains and cocoyam starch from Colocasia esculenta L. Schott tubers, were co-processed with montmorillonite clay (MMT) and evaluated as a directly compressible excipient in tramadol tablet formulations. The effects of different starch-to-clay ratios on the material and drug release properties of the resulting tablets were evaluated.

Material and methods: The starch-clay composites were prepared by heating a dispersion of the starch in distilled water, then precipitating the dispersion with an equal volume of 95% ethanol. The starch-clay composites were characterized and used as direct compression excipients for the preparation of tramadol tablets. The mechanical and drug release properties of the tablets were evaluated.

Results: Co-processing MMT with the starches yielded starch-clay composites with different material and tablet properties than the pristine starches. The co-processed starch-MMT biocomposites exhibited improved flowability and compressibility over the pristine starches. The mechanical and drug release properties of tramadol tablets containing starch-clay composites were significantly better than those containing only pristine starches. The properties of the starch-clay composites were not related to the botanical source of the starches.

Conclusions: The study showed that starch-clay biocomposites could be used in the controlled release of tramadol.

Background: Ibuprofen is used both for acute and chronic disorders, such as ankylosing spondylitis, osteoarthritis and rheumatoid arthritis; however, ibuprofen causes gastrointestinal disturbances. Therefore, it would be desirable to design it as a sustained-release preparation.

Objectives: To design ibuprofen microbeads using polymers obtained from Xanthosoma sagittifolium starch and Dillenia indica mucilage to provide sustained-release delivery of ibuprofen.

Material and methods: The polymers were extracted using standard methods and characterized by their material, physicochemical, elemental, and rheological profiles. Microbeads loaded with ibuprofen were prepared using the ionotropic gelation method utilizing blends of the polymers and sodium alginate. The microbeads were evaluated using particle shape, particle size, swelling index, entrapment efficiency, and release assays.

Results: The results showed that the polymers have distinct material and physicochemical properties unique to their botanical sources. The microbeads were spherical and free-flowing, and they rolled without friction. The swelling properties ranged from 47.62 ±2.74% to 79.49 ±3.66%. The particle size of the microbeads ranged from 88.14 ±68.57 μm to 214.90 ±66.95 μm, while the encapsulation efficiencies ranged from 20.67 ±4.66% to 83.61 ±6.35%. The dissolution times suggested that the concentration of the natural polymers in the bead formulation could be used to modulate the dissolution properties. Generally, formulations containing the mucilage yielded higher dissolution times than those containing the starch. The kinetics of drug release from the microbeads containing the polymer blends generally fitted the Korsmeyer-Peppas model. The highest similarity was found between formulations C6 and D4 with f2 of 81.07.

Conclusions: The microbeads prepared with polymers obtained from Xanthosoma and Dillenia showed acceptable physicochemical properties, dependent upon polymer type, blend and concentration.