Polimery w medycynie最新文献

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.

Background: Skin, the first barrier to pathogens, loses its integrity and function after an injury. The presence of an antibacterial dressing at the wound site may prevent bacterial invasion and also improve the healing process.

Objectives: The current study aimed to fabricate a biomimetic membrane with antibacterial properties for healing chronic wounds.

Material and methods: The membranes, fabricated through electrospinning, are comprised of poly(ethylene oxide) (PEO) and zinc oxide nanoparticles (ZnO-NPs) as the main biomaterial and antibacterial agent, respectively. Antibacterial activity, cell attachment and viability were tested to evaluate the biological properties of the membranes. The optimal cell compatible concentration of ZnO-NPs was determined for further studies. In vitro characterization of the membranes was performed to confirm their suitable properties for wound healing.

Results: The antibacterial PEO/ZnO-NP membrane containing 2% of nanoparticles showed no cell toxicity, and human fibroblast cells were able to adhere and proliferate on the scaffold. The in vitro results from the tensile test, wettability, porosity, and protein adsorption revealed appropriate properties of the membrane as a scaffold for skin tissue engineering.

Conclusions: Synthetic polymers have been widely used for tissue engineering applications. The proper characteristics of PEO nanofibers, including a high ratio of surface/volume, moderate hydrophilicity and good mechanical properties, make this polymer interesting for skin regeneration. The results demonstrate the potential of the antibacterial PEO/ZnO-NP membrane to be used as an engineered scaffold to improve the wound healing process.

In the development of drug delivery systems, an oral drug delivery system is the preferred route of drug administration. Many components play an important role in developing a drug delivery system. Amongst those components, polymers have evolved with these systems. Macromolecule compounds consisting of many monomer units which are joined to each other by different bonds are known as polymers. For drugs that are absorbed primarily in the upper gastrointestinal tract, floating drug delivery systems offer an additional advantage. The purpose behind this review was to focus on different types of floating drug delivery systems and different types of polymers used in floating drug delivery systems, focusing on acrylic acid derivatives and their applications. In this review, the main emphasis is on acrylic acid derivative polymers, their formulation and grades, and various patents on these types of polymers. Based on the literature survey, mainly 2 types of polymers are used in this drug delivery system; i.e., natural and synthetic. Examples of natural polymers are xanthan gum, guar gum or chitosan, and synthetic polymers include acrylic acid derivatives and hydroxylpropyl methylcellulose (HPMC). Eudragit and Carbopol are the most widely used acrylic acid derivatives.

Background: Green route biosynthesis of silver nanoparticles using Trichoderma viride (T. viride) filtrate (TVFSNPs) can serve as an alternative to antibiotics and as an effective drug delivery to combat cancer and act as an immune-stimulator.

Objectives: To biosynthesize silver nanoparticles (SNPs) with T. viride filtrate using green route and to characterize and determine the cytotoxic and immunomodulatory potential of nanoparticles.

Material and methods: Trichoderma viride filtrate was used for biosynthesizing SNPs. The biosynthesized SNPs were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The cytotoxic properties against Hep‑2C and rotavirus and the immunomodulatory potential were evaluated.

Results: Trichoderma viride filtrate was able to bio-reduce AgNO3 to SNPs. The surface plasmon resonance peak was at 450 nm. The presence of aldehydes, amino acids, ethers, esters, carboxylic acids, hydroxyl groups, and phenol among others indicates the capping and stabilization of proteins in the nanoparticles. The nanoparticles were spherical with a size of 0.1-10.0 nm. The EDX analysis revealed a strong signal of silver (Ag). The TVFSNPs had a cytotoxic effect on Hep2C and rotavirus in a dose-dependent manner and increased the production of immunoglobulin (Ig) A (IgA) and IgM.

Conclusions: Trichoderma viride filtrate contained some biochemicals that can bio-reduce silver nitrate (AgNO3) for SNPs biosynthesis. The anticancer and immunostimulatory potential justifies the biomedical application and biotechnological relevance of T. viride.