Combined laser and photodynamic treatment in extensive purulent wounds

Recently, photodynamic therapy (PDT) has been used for the treatment of festering wounds and trophic ulcers. An important advantage of PDT is its ability to affect bacterial cultures that are resistant to antibiotics. However the use of PDT alone does not usually guarantee a stable antiseptic effect and cannot prevent an external infection of wounds and burns. In this work attention is focused on the healing of the extensive soft tissues wounds with combined laser therapy (LT) and PDT treatment. At the first stage of this process festering tissues (for example spacious purulent wounds with area more than 100 cm²) were illuminated with high-energy laser beam (with power 20 W) in continues routine. The second stage involves “softer” PDT affect, which along with the completion stages of destruction pathological cells, stimulating the process of wound granulation and epithelization. Also, according to our previous results, photosensitizer (photoditazin) is introduced inside the wound with different amphiphilic polymers for increasing the PDT efficacy.     

Review of nanofluids for heat transfer applications

Research on nanofluids has progressed rapidly since its enhanced thermal conductivity was first repotted about a decade ago,though much controversy and inconsistency have been reported,and insufficient understanding of the formulation and mechanism of nanofluids further limits their applications.This work presents a critical review of research on heat transfer applications of nanofluids with the aim of identifying the limiting factors so as to push forward their further development.     

新开花粉蛋白的盐酸胍去折叠过程

本文利用荧光光谱和园二色光谱了新开花粉蛋白的盐酸胍去折叠过程。结果显示：新开花粉蛋白的盐酸胍去折叠是一个只包含天然蛋白和变性终态的二态过程,与已经报道的天花粉蛋白的盐酸胍去折叠的过程不同。     

Interaction of polyanions with electroneutral liposomes in a slightly acidic medium

In this study, the interaction between poly(styrene sulfonic acid), polyacrylic acid, poly(meth-acrylic acid), poly(L-glutamic acid), poly(vinyl sulfate), and ternary copolymer of styrene with maleic anhydride and methacrylic acid (3: 2: 1), as well as DNA with lipid vesicles composed of zwitterion (electroneutral) lipid phosphatidylcholine, has been investigated. The methods of centrifuge ultrafiltration and dynamic light scattering reveal that, at pH 4.2, all polyacids under study are effectively adsorbed on the phospholipid membrane. The polymer-membrane complex is stabilized by hydrogen bonds and hydrophobic interactions in addition to electrostatic bonds. Even though, to a greater or lesser extent, all polyacids are capable of undergoing adsorption on the membrane in a slightly acidic medium, their effect on the membrane permeability is substantially different and is correlated with the ability of a polymer to form multiple interactions with phospholipid molecules. Poly(acrylic acid), poly(methacrylic acid), poly(styrene sulfonic acid), and the ternary copolymer of styrene with maleic anhydride and methacrylic acid can produce the membrane pores that are permeable to low-molecular-mass compounds. At the same time, poly(L-glutamic acid), poly(vinyl sulfate), and DNA exert no effect on the membrane permeability, although they are sorbed on the membrane surface.     

CD40mAb adjuvant induces a rapid antibody response that may be beneficial in post-exposure prophylaxis

Active vaccination can be effective as a post-exposure prophylaxis, but the rapidity of the immune response induced, relative to the incubation time of the pathogen, is critical. We show here that CD40mAb conjugated to antigen induces a more rapid specific antibody response than currently used immunological adjuvants, alum and monophosphoryl lipid A™.     

Intermolecular interactions governing solubilization in micelles of poly(alkylene oxide) surfactants

Partition coefficients for 39 low-molecular-mass compounds between water and micelles of an ethylene oxide-propylene oxide block copolymer (Pluronic P85) and the monolauryl ether of poly(ethylene oxide) (Brij 35) have been measured by the methods of fluorescence spectroscopy, fluorescence anisotropy, and dialysis kinetics. The tested compounds include aromatic hydrocarbons, phenols, naphthols, xanthene dyes, anthracycline antibiotics, and porphyrins. The multifactor analysis of the partition coefficients in terms of the linear free-energy relationships has been performed. It has been shown that the H-donating ability of compounds facilitates their solubilization in Pluronic micelles and has no effect on solubilization in micelles of monolauryl ether of poly(ethylene oxide). This difference indicates that, when solubilization occurs in Pluronic micelles, the compounds under study appear in a hydrophobic core composed of poly(propylene oxide) blocks.     

Doxorubicin-poly(acrylic acid) complexes: interaction with liposomes

Complexation of antitumor drug, doxorubicin (DOX), with poly(acrylic acid) (PAA) in buffer solutions was examined. The DOX-to-PAA binding was governed by electrostatic and stacking interactions resulting in a complex of characteristic composition with a PAA/DOX = 1.6 molar ratio. Sizes of the complex particles were found to lie in 600-900-nm range. However, the particles were able to interact with small neutral egg yolk lecithin liposomes (80-100 nm in diameter), a ternary DOX/PAA/liposome complex being formed. The observations and conclusions we made may be useful for interpreting biological effects of polymer-based bioactive constructs.     

Development of novel formulations for photodynamic therapy on the basis of amphiphilic polymers and porphyrin photosensitizers. Porphyrin-polymer complexes in model photosensitized processes

We have studied the effect of amphiphilic polymers with different structure (polyvinylpyrrolidone, polyethyleneoxide and a triblock copolymer of ethylene- and propyleneoxide—(Pluronic F127)) on the photoactivity of a hematoporphyrin derivative (dimegin). It has been shown that such polymers can cause a considerable increase in the porphyrin photosensitizer (PPS) activity both in the process of singlet oxygen photogeneration and in the reaction of a substrate photooxidation in D2O and water. Among the studied polymers, polyvinylpyrrolidone appeared to have a most significant influence onto the photoactivity of dimegin. We attribute the observed effect of the amphiphilic polymers on the photoactivity of dimegin to the presence of polymer-porphyrin interactions resulting in the porphyrin disaggregation in aqueous phase. Using 1H NMR spectroscopy, we have found that dimegin binds to the polymers via the PPS interaction mainly with the hydrophobic fragments of polymeric macromolecules. However, in the case of polyvinylpyrrolidone we observed also PPS interactions with the hydrophilic fragments of macromolecules.