Polimery w medycynie最新文献

The available information on the abundance of restorative plants on earth is incomplete, and the data regarding botanicals from various countries differ significantly. The substantial development of the worldwide natural botanical market is attributable to the expanding revenue of global drug companies trading herbal medicines. This essential type of traditional medical care is depended on by approx. 72-80% of individuals. Even though numerous restorative plants are readily used, they have never been subject to the same strict quality guidelines as conventional drugs. Nonetheless, it is vital to have specific organic, phytochemical, and molecular tools and methods for identifying restorative plant species so that traditional and novel plant products can be safely used in modern medicine. Molecular biotechnology approaches provide a reliable and accurate way to identify botanicals and can be used to ensure the safety and efficacy of plant-based products. This review explores various molecular biotechnology approaches and methods for identifying botanicals.

In this review, benefits and drawbacks of the process of spray drying and nano spray drying with regard to the manufacturing of polymeric particles for pharmaceutical applications are discussed. Spray drying has been used for many years in the food, chemical and pharmaceutical industries for converting liquids into solids, in order to form products of uniform appearance. The construction of spray dryer enables to atomize the liquid into small droplets, which ensures a large surface area for heat and mass transfer, and significantly shortens the processing. Each droplet dries to an individual solid microparticle of characteristic features that can be tailored by optimizing formulation variables and critical process parameters. Since spray drying technology is easy to scale up and can be used for drying almost any drug in a solution or suspension, there are numerous examples of products in clinical use, in which this process has been successfully applied to improve drug stability, enhance bioavailability or control its release rate. In recent years, nano spray drying technology has been proposed as a method for lab-scale manufacturing of nanoparticles. Such an approach is of particular interest at early stages of drug development, when a small amount of new chemical entities is available. Here, the nebulization technique is used for feed atomization, while laminar gas flow in the drying chamber ensures gentle drying conditions. Moreover, electrostatic collectors have gradually replaced cyclone separators, ensuring high effectiveness in producing solid nanoparticles, even if a small volume of the sample is processed.

Background: Mucilage and pectin are both natural polymers with the advantages of availability and biodegradability. Microspheres made from biodegradable polymers can break down naturally after performing their tasks.

Objectives: The study aimed to use mucilage and pectin from the leaves of Talinum triangulare (Jacq.) Willd. as polymer matrices for the formulation of microspheres, with ibuprofen as the model drug.

Material and methods: Both polymers were examined under a microscope and evaluated using measurements of viscosity, density, flow properties, swelling power, elemental analysis, Fourier-transform infrared spectroscopy (FTIR), and the degree of esterification (DE) for pectin. The microspheres were prepared using the ionotropic gelation method and alginate:mucilage/pectin at ratios of 1:1 and 1:2. They were assessed for swellability, drug entrapment effectiveness and drug release profile.

Results: The mucilage particles were ovoid while pectin particles were irregularly shaped. Pectin had higher particle, bulk and tapped densities than mucilage, while mucilage had a higher swelling power and a better flow than pectin. Talinum triangulare pectin is a low-methoxyl pectin with a DE of 7.14%. The FTIR spectra showed no interaction between the polymers and ibuprofen. The surface morphology of the microspheres without ibuprofen was smooth, while those with ibuprofen revealed a spongy-like mesh. The swelling power of the microspheres was higher in phosphate buffer with a pH of 7.2 than in distilled water. The entrapment efficiency ranged within 39.57-60.43% w/w, with microspheres containing alginate:mucilage/pectin ratio of 1:1 having higher entrapment efficiency. Microspheres with polymer at a ratio of 1:1 provided a longer release (>2 h), while microspheres with polymer blend of 1:2 provided an immediate release of ibuprofen.

Conclusions: The polymers of T. triangulare could be used as matrices in microsphere formulations.

Background: Irvingia gabonensis kernel polymer has gained attention in drug delivery systems because of its compatibility and degradation under natural and physiological conditions.

Objectives: This study aimed to evaluate Irvingia gabonensis polymer as a matrix system for the controlled delivery of ibuprofen in comparison to xanthan gum and hydroxypropylmethylcellulose (HPMC).

Material and methods: Irvingia gabonensis polymer was extracted using established methods and dried using the ovenand freeze-drying methods. Ibuprofen tablets were prepared by direct compression and the effects of polymer concentration (10-50%), excipients (lactose, microcrystalline cellulose and dicalcium phosphate dihydrate) and polymers (xanthan gum and HPMC) on the mechanical and drug release properties of the tablets were evaluated. Density measurements and the Heckel and Kawakita equations were used to determine the compression properties of the tablets. Friability, crushing strength and the crushing strength-friability ratio (CSFR) were used to evaluate the mechanical properties of the tablets, while dissolution times were used to evaluate drug release from the matrices. The drug release mechanisms were determined by fitting the dissolution data into classic kinetic equations.

Results: Irvingia gabonensis polymer deformed plastically with a fast onset and a high amount of plastic deformation compared with xanthan gum and HPMC. This polymer was directly compressible and formed intact non-disintegrating tablets; the mechanical and dissolution properties of Irvingia gabonensis polymer tablets generally decreased with increasing concentration of ibuprofen. The ranking of dissolution times was xanthan gum > freeze-dried Irvingia gabonensis > HPMC > oven-dried Irvingia gabonensis. The addition of the excipients improved the mechanical properties of the tablets, aided ibuprofen release, and altered the release kinetics, which was largely defined by the Korsmeyer-Peppas model. Increasing the proportion of xanthan gum and HPMC in the matrices resulted in a decreased amount of ibuprofen released after 9 h, with xanthan gum having a greater effect.

Conclusions: Irvingia gabonensis polymer matrices may be effective in the preparation of controlled release tablets, and their right combination with xanthan gum or HPMC could provide a time-independent release for longer durations.

Background: Temporary prosthesis protects the oral tissues, in addition to providing aesthetic look and masticatory function until a definitive prosthesis is manufactured.

Objectives: To evaluate the effect of glaze and 0.12% chlorhexidine (CHX) on the physical and mechanical properties of bis-acryl, and to evaluate the antimicrobial efficacy of CHX.

Material and methods: Eighty specimens of bis-acryl resin were made. Over 40 of them the glaze was applied. One specimen with and 1 specimen without glaze were placed in niches of an appliance manufactured for each patient. Each of the 20 volunteers received 2 devices. Initially, the volunteers used one device and treated it with sucrose for 7 days (control), and later they used the other device and treated it with sucrose and CHX for 7 days (test). Color, microhardness, roughness, surface energy, and insoluble extracellular polysaccharides (EPS) tests were performed. All results were submitted to the Tukey's test, with the exception of the EPS results, which were submitted to the Student's t test.

Results: The ΔE00 of the unglazed control group was significantly higher than that of the unglazed test group. In all groups, a significant decrease in microhardness occurred over time. At both times, the glaze significantly increased the microhardness of the specimens (in all the glazed groups). At the final time, the test glaze group showed significantly higher microhardness compared with the control glaze group. Roughness in the groups without glaze increased significantly with CHX treatment over time. At both times, the glaze generated a significant reduction in roughness in the control and test groups. There was a significant reduction in surface energy over time in all groups. In most comparisons, the glazed groups showed significantly higher surface energy values compared with the unglazed control group. At the final time point, the unglazed test group showed a significantly higher surface energy value than the unglazed control group; and the glazed test group showed a significantly higher surface energy value compared with the glazed control group. The resins that received CHX had a significantly lower amount of biofilm.

Conclusions: Color values were clinically acceptable in all tested groups. At both time points, the roughness values were clinically acceptable only in the glazed groups. Glaze increased the microhardness of the specimens. Microhardness and surface energy were reduced over time in all groups. Chlorhexidine can help prevent microhardness degradation. Glaze and CHX can increase surface energy. Chlorhexidine reduced the amount of bacterial biofilm.

Background: The Textus Bioactiv Ag membrane is an active dressing for the treatment of chronic wounds such as venous stasis ulcers and burns.

Objectives: Determination of the transport and internal energy conversion properties of the Textus Bioactiv Ag membrane using the Kedem-Katchalsky-Peusner model. This model introduces the coefficients Lij necessary to calculate the degree of coupling (lij, QL), energy conversion efficiency (eij), dissipated energy (S-energy), free energy (F-energy), and internal energy (U-energy).

Material and methods: The research material was the Textus Bioactiv Ag membrane that is used as an active dressing in the treatment of difficult-to-heal wounds, and KCl aqueous solutions. The research methods employed Peusner's formalism of network thermodynamics and Kedem and Katchalsky's thermodynamics of membrane processes. To calculate the Lij coefficients, we used hydraulic conductivity (Lp), diffusion conductivity (ů) and reflection (ó) coefficients to perform experimental measurements in different conditions.

Results: The Lp coefficient for the Textus Bioactiv Ag membrane is nonlinearly dependent on the average concentrations of the solutions. In turn, the ů and ó coefficients are nonlinearly dependent on the differences in osmotic pressures (Äđ). An increase in the Äđ causes the Textus Bioactiv Ag membrane to become more permeable and less selective for KCl solutions. The coefficients of Peusner (Lij), couplings (lij, QL), energy conversion efficiency (eij), S-energy, F-energy, and U-energy also depend nonlinearly on Äđ. Our results showed that for higher concentrations of KCl solutions transported through the Textus Bioactiv Ag membrane, the coupling and energy conversion coefficients were greater for larger Äđ up to their maximum values for large Äđ. Coupling of the membrane structure with the electrolyte flux through the membrane is observed for Äđ greater than 10 kPa.

Conclusions: Textus Bioactiv Ag membrane dressings possess the properties of a solution component separator as well as an internal energy converter.

Background: Epithelial cells are the first barrier to any microbial invasion. Finding a safe and affordable substance to stimulate the innate immune response of epithelial cells is one of the main challenges immunologists and vaccine manufacturers are facing.

Objectives: This study aimed to show the comparative effect of sterile bacterial secretion (SBS) and Pseudomonas aeruginosa bacterial cell isolates obtained from burn wound infections on the ability of human epithelial cells (HECs) to produce interleukin (IL)-1β and tumor necrosis factor alpha (TNF-α) in vitro.

Material and methods: The HEC cultures were exposed to P. aeruginosa 8 (Pa 8), Pa 2 and Pa 1 bacterial cells (isolated from burn wound infections). The other 3 groups of HECs were exposed to 50 μL of sterile, endotoxin-free SBS of Pa 8, Pa 2 and Pa 1. The time course of changes in IL-1β mRNA, TNF-α mRNA, IL-1β, and TNF-α was examined.

Results: Moderate (p < 0.05) elevations of IL-1β mRNA in HECs and IL-1β protein in the supernatant of the HEC culture were observed following exposure to SBS of Pa 8, Pa 2 and Pa 1 at most time points. High elevation (p < 0.05) of IL-1β was seen in the supernatant of the HEC culture that was exposed to bacterial cells (Pa 8, Pa 2 and Pa 1). Similar results were found when TNF-α mRNA was measured in HECs and TNF-α in the supernatant of the HEC cultures after exposure to bacterial cells (Pa 8, Pa 2 and Pa 1) and the SBS of Pa 8, Pa 2 and Pa 1.

Conclusions: This is the first time that the capacity of SBS to generate epithelial cell pro-inflammatory cytokines in vitro has been shown. In other words, SBS enhanced a nonspecific immune response, which opens the door to the possibility of using SBS from P. aeruginosa as an adjuvant in the future.

Polymeric micelles and capsules are promising candidates for carriers of antineoplastic medications. Biodegradability and broadly defined biocompatibility are the key features that should always characterize polymers intended for medical applications. A well-designed delivery system ought to ensure the safe transport of chemotherapeutic agents to the target area and thus minimize systemic exposure to these drugs, limiting their toxic effect, preferably to the cancer cells. Polymeric micelles are often tailored for encapsulation of water-insoluble drugs. Micellar structures are usually fabricated as a result of self-assembly of various amphiphilic block copolymers in aqueous environment. More advanced methods are used to form capsules with a liquid core and a shell made of fused polymer nanoor microparticles. Such a coating can have homogeneous or heterogeneous composition. Janus and patchy capsules are usually characterized by more useful and advanced properties. Although some polymeric carriers are designed for a sustained release of the cargo, more sophisticated approaches involve payload liberation on demand under the influence of selected chemical or physical stimuli. The variety of available polymers and a wide range of possibilities of forming copolymers from different kind of monomers make polymeric materials ideal for the production of drug delivery systems with the desired properties. The aim of the present review is to sum up selected aspects of the use of polymeric micelles as carriers of cytostatic drugs, taking into account clinical applications. The additional objective is to show the studies on creating alternative systems based on stimuli-responsive capsules with shells made of polymeric particles.

Background: Burkholderia cepacia adhesion and biofilm formation onto abiotic surfaces is an important feature of clinically relevant isolates. The in vitro biofilm formation of B. cepacia onto coated indwelling urinary catheters (IDCs) with moxifloxacin has not been previously investigated.

Objectives: To examine the ability of B. cepacia to form biofilms on IDCs and the effect of coating IDCs with moxifloxacin on biofilm formation by B. cepacia in vitro.

Material and methods: The adhesion of B. cepacia to coated and uncoated IDCs with moxifloxacin was evaluated. Pieces of IDCs were coated with moxifloxacin (adsorption method). The spectrophotometric method was used to check moxifloxacin leaching into tubes. Coated and uncoated tubes were incubated with 107 colony forming units (cfu)/mL of B. cepacia. The viable bacterial count was used to count the number of bacteria adhered to coated and uncoated IDC pieces.

Results: A significant adhesion of B. cepacia to uncoated IDC pieces started 15 min after the incubation in a bacterial suspension (107 cfu/mL). A maximum adhesion was observed at 48 h. The pretreatment of IDCs with 100 μg/mL of moxifloxacin produced the best adsorption of antibiotic onto the IDCs. Coating IDC pieces with moxifloxacin significantly reduced the adhesion and biofilm formation of B. cepacia (p < 0.05) at various time intervals (1 h, 4 h and 24 h).

Conclusions: The present study has demonstrated for the first time that coated IDCs with moxifloxacin reduce B. cepacia adhesion and biofilm formation. This finding has opened the door to the production of the new generation IDCs that prevent bacteria from attaching and forming biofilms.

As the number of new drug candidates that are poorly soluble in water grows, new technologies that enable the enhancement of their solubility are needed. This is the case with amorphous solid dispersions (ASDs) that, nowadays, not only ensure the solubility, but can also be used to control the release rate of poorly soluble drugs. However, this dosage form must overcome the major disadvantage of ASDs, which is limited stability upon storage. Thus, a thorough knowledge on polymeric carriers that can enhance drug solubility while ensuring stability in the amorphous form is necessary. In this review, the state of the art in the application of Kollidon® VA 64 (copovidone) and Soluplus® (graft copolymer of polyvinyl caprolactam-polyvinyl acetate and poly(ethylene glycol) (PEG)) in the manufacturing of ASDs over the last 20 years is presented. Apart from the classical methods, namely solvent evaporation or melting, more advanced technologies such as pulse combustion drying, high-speed electrospinning and single-step 3D printing are described. It has been shown that both the dissolution rate (in vitro) and enhancement in bioavailability (in vivo) regarding poorly soluble active ingredients of natural or synthetic origin are possible using these matrix-forming polymers.