Photodynamic and Nail Penetration Enhancing Effects of Novel Multifunctional Photosensitizers Designed for The Treatment of Onychomycosis

Novel multifunctional photosensitizers (MFPSs), 5,10,15‐tris(4‐N‐methylpyridinium)‐20‐(4‐phenylthio)‐[21H,23H]‐porphine trichloride (PORTH) and 5,10,15‐tris(4‐N‐methylpyridinium)‐20‐(4‐(butyramido‐methylcysteinyl)‐hydroxyphenyl)‐[21H,23H]‐porphine trichloride (PORTHE), derived from 5,10,15‐Tris(4‐methylpyridinium)‐20‐phenyl‐[21H,23H]‐porphine trichloride (Sylsens B) and designed for treatment of onychomycosis were characterized and their functionality evaluated. MFPSs should function as nail penetration enhancer and as photosensitizer for photodynamic treatment (PDT) of onychomycosis. Spectrophotometry was used to characterize MFPSs with and without 532 nm continuous‐wave 5 mW cm^?2 laser light (± argon/mannitol/NaN₃). Nail penetration enhancement was screened (pH 5, pH 8) using water uptake in nails and fluorescence microscopy. PDT efficacy was tested (pH 5, ± argon/mannitol/NaN₃) in vitro with Trichophyton mentagrophytus microconida (532 nm, 5 mW cm^?2). A light‐dependent absorbance decrease and fluorescence increase were found, PORTH being less photostable. Argon and mannitol increased PORTH and PORTHE photostability; NaN₃ had no effect. PDT (0.6 J cm^?2, 2 μm ) showed 4.6 log kill for PORTH, 4.4 for Sylsens B and 3.2 for PORTHE (4.1 for 10 μm ). Argon increased PORTHE, but decreased PORTH PDT efficacy; NaN₃ increased PDT effect of both MFPSs whereas mannitol increased PDT effect of PORTHE only. Similar penetration enhancement effects were observed for PORTH (pH 5 and 8) and PORTHE (pH 8). PORTHE is more photostable, effective under low oxygen conditions and thus realistic candidate for onychomycosis PDT.     

Effect of 808 nm Diode Laser on Swimming Behavior,Food Vacuole Formation and Endogenous ATP Production of Paramecium primaurelia (Protozoa)

Photobiomodulation (PBM) has been used in clinical practice for more than 40 years. To clarify the mechanisms of action of PBM at cellular and organism levels, we investigated its effect on Paramecium primaurelia (Protozoa) irradiated by an 808 nm infrared diode laser with a flat‐top handpiece (1 W in CW). Our results led to the conclusion that: (1) the 808 nm laser stimulates the P. primaurelia without a thermal effect, (2) the laser effect is demonstrated by an increase in swimming speed and in food vacuole formation, (3) the laser treatment affects endogenous adenosine triphosphate (ATP) production in a positive way, (4) the effects of irradiation dose suggest an optimum exposure time of 50 s (64 J cm^?2 of fluence) to stimulate the Paramecium cells; irradiation of 25 s shows no effect or only mild effects and irradiation up to 100 s does not increase the effect observed with 50 s of treatment, (5) the increment of endogenous ATP concentration highlights the positive photobiomodulating effect of the 808 nm laser and the optimal irradiation conditions by the flat‐top handpiece.     

Susceptibility of Ureaplasma urealyticum to Methylene Blue‐Mediated Photodynamic Antimicrobial Chemotherapy: An in vitro Study

The aim of this study was to detect the susceptibility of Ureaplasma urealyticum to methylene blue‐mediated photodynamic antimicrobial chemotherapy (PACT). Three U. urealyticum strains including the standard serotype 1 and 5, and a clinically collected strain were used in this study. Strains were first incubated in 96‐well culture plates in the presence of methylene blue with decreasing concentrations (from 1 to 0.015625 mg mL^?1) for 20 or 60 min, and then submitted to irradiation with a light‐emitting diode laser with a power density of 100 mW cm^?2 for 8, 17, 34 or 68 min. Regrowth of the strains was performed soon after irradiation. A significant inactivation effect was observed after PACT. Longer incubation time induced more extensive inactivation of U. urealyticum. No difference in response to PACT was observed between the two biovars of U. urealyticum. It was concluded that PACT had a significant inactivation effect on U. urealyticum, and it might be a promising alternative treatment for resistant U. urealyticum infections.     

Biomodulation of Inflammatory Cytokines Related to Oral Mucositis by Low‐Level Laser Therapy

This study evaluated the effects of LLLT on the expression of inflammatory cytokines related to the development of oral mucositis by gingival fibroblasts. Primary gingival fibroblasts were seeded on 24‐well plates (10⁵ cells/well) for 24 h. Fresh serum‐free culture medium (DMEM) was then added, and cells were placed in contact with LPS (Escherichia coli, 1 μg mL^?1), followed by LLLT irradiation (LaserTABLE—InGaAsP diode prototype—780 nm, 25 mW) delivering 0, 0.5, 1.5 or 3 J cm^?². Cells without contact with LPS were also irradiated with the same energy densities. Gene expression of TNF‐α, IL‐1β, IL‐6 and IL‐8 was evaluated by Real‐Time PCR, and protein synthesis of these cytokines was determined by enzyme‐linked immunosorbent (ELISA) assay. Data were statistically analyzed by the Kruskal–Wallis test, complemented by the Mann–Whitney test (P < 0.05). LPS treatment increased the gene expression and protein synthesis of TNF‐α, IL‐6 and IL‐8, while the expression of IL‐1β was not affected. For LPS‐treated groups, LLLT promoted significant decreases in the expression of TNF‐α, IL‐6, and IL‐8 at 1.5 J cm^?2 and 3 J cm^?2. These results demonstrate that LLLT promoted a beneficial biomodulatory effect on the expression of inflammatory cytokines related to oral mucositis by human gingival fibroblasts.     

High Final Energy of Low‐Level Gallium Arsenide Laser Therapy Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen Remodeling

The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8 J, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n = 10); Injured (I, n = 10) and Injured and laser treated (Injured/LLLT, n = 10). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The applications of the laser (904 nm, 50 mW average power) were initiated 24 h after injury, at energy density of 69 J cm^?1 for 48 s, for 5 days, to two points of the lesion. Twenty‐four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF‐α, TGF‐β, MyoD, and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (P < 0.05) without changes in the collagen remodeling. In addition, the Injured/LLLT group presented a significant decrease in the expression of TNF‐α and myogenin compared to the injured group (P < 0.05). The results suggest that the GaAs laser, using a high final energy after cryoinjury, promotes muscle recovery without changing the collagen remodeling in the muscle extracellular matrix.     

Low‐level Laser Therapy Ameliorates CCl4‐induced Liver Cirrhosis in Rats

This study investigated the effects of low‐level laser therapy (LLLT) in the liver function, structure and inflammation in a experimental model of carbon tetrachloride (CCl₄)‐induced liver cirrhosis. Wistar rats were divided into Control, LLLT, CCl₄ and CCl₄+LLLT groups. CCl₄ groups received CCl₄ (0.4 g kg^?1; i.p.), three times a week, for 12 weeks. A 830 nm LLLT was performed with a continuous wave, 35 mW, 2.5 J cm^?2 per point, applied to four points of the liver (right and left upper and lower extremities, in the four lobes of the liver) for 2 weeks. Liver structure and inflammation (cirrhotic areas, collagen deposition, inflammation, density of Kupffer and hepatic stellate cells) and function (aspartate aminotransferase, alkaline phosphatase, gamma glutamyltransferase, lactate dehydrogenase, total proteins and globulins) were evaluated. LLLT significantly reduced CCl₄‐increased aspartate aminotransferase (P < 0.001), alkaline phosphatase (P < 0.001), gamma‐glutamyl transferase (P < 0.001) and lactate dehydrogenase (P < 0.01) activity, as well as total proteins (P < 0.05) and globulins (P < 0.01). LLLT also reduced the number of cirrhotic areas, the collagen accumulation and the hepatic inflammatory infiltrate. Of note, LLLT reduced CCl₄‐increased number of Kupffer cells (P < 0.05) and hepatic stellate cells (P < 0.05). We conclude that LLLT presents beneficial effects on liver function and structure in an experimental model of CCl₄‐induced cirrhosis.     

Effect of thiophene spacers in benzodithiophene‐based polymers for organic electronics

Poly{2,6‐bis(thiophene‐2‐yl)‐4,8‐bis(5‐dodecylthiophen‐2‐yl)benzo[1,2‐b :4,5‐b' ]dithiophene} [poly(Th‐bDTBDT‐Th)] was successfully synthesized through Stille coupling polymerization. The addition of the thiophene spacer groups between the benzodithiophene units resulted in improved performance in optoelectronic devices. This was attributed to the reduced lamellae stacking distance in thin film with prominent π–π stacking peak indicating close assembly of poly(Th‐bDTBDT‐Th). Spacing between the benzodithiophene units in poly(Th‐bDTBDT‐Th) helped the close packing of dodecyl chains and generated improved π stacking interaction. For poly(Th‐bDTBDT‐Th), the measured average field effect mobility was 2.32 × 10^?3 cm² V^?1 s^?1 and average hole mobility in vertical direction was 2.92 × 10^?5 cm² V^?1 s^?1. Charge transport in both directions was improved by one order of magnitude with the presence of the thiophene spacer. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 3942–3948     

Effects of Enhanced UV‐B Radiation on Biochemical Traits in Postharvest Flowers of Medicinal Chrysanthemum

This article reported UV‐B radiation effects on biochemical traits in postharvest flowers of chrysanthemum. The experiment included six levels of UV‐B radiation (UV0, 0 μW cm^?2; UV50, 50 μW cm^?2; UV200, 200 μW cm^?2; UV400, 400 μW cm^?2; UV600, 600 μW cm^?2 and UV800, 800 μW cm^?2). Enhanced UV‐B radiation significantly increased hydrogen peroxide content (except for UV50), but did not evidently affect malondialdehyde content in flowers. Chlorophyll b and total chlorophyll content were significantly increased by UV600 and UV800. UV400 and UV600 significantly increased anthocyanins, carotenoids and UV‐B absorbing compounds content, and the activities of phenylalanine ammonia lyase (PAL) and cinnamic acid‐4‐hydroxylase (C4H) over the control. 4‐coumarate CoA ligase (4CL) activity was significantly decreased by enhanced UV‐B radiation (except for UV50). The relationships between UV‐B radiation intensities and the activities of secondary metabolism enzymes were best described by a second‐order polynomial. The R² values for UV‐B radiation intensities and the activities of PAL, C4H and 4CL were 0.8361, 0.5437 and 0.8025, respectively. The results indicated that enhanced UV‐B radiation could promote secondary metabolism processes in postharvest flowers, which might be beneficial for the accumulation of medically active ingredients in medicinal plants. The optimal UV‐B radiation intensities in the study were between UV400‐UV600.     

Why is Rose Bengal More Phototoxic to Fibroblasts In Vitro Than In Vivo?

Photosensitized protein cross‐linking has been recently developed to seal wounds and strengthen tissue. Although the photosensitizing dye, Rose Bengal (RB), is phototoxic to cultured cells, cytotoxicity does not accompany RB‐photosensitized tissue repair in vivo. We investigated whether the environment surrounding cells in tissue or the high irradiances used for photo–cross‐linking inhibited RB phototoxicity. Fibroblasts (FB) grown within collagen gels to mimic a tissue environment and monolayer cultured FB were treated with RB (0.01–1 mm ) and the high 532 nm laser irradiances used in vivo for tissue repair (0.10–0.50 W cm^?2). Monolayer FB were substantially more sensitive to RB photosensitization: the LD₅₀ was >200‐fold lower than that in collagen gels. Collagen gel protection was associated with increased Akt phosphorylation, a prosurvival pathway. RB phototoxicity in collagen gels was 25‐fold greater at low (0.030 W cm^?2) that at high (0.50 W cm^?2) irradiances. Oxygen depletion at high irradiance only partially accounted for the irradiance dependence of phototoxicity as replacing air with nitrogen only increased the LD₅₀ by four‐fold in monolayers. These results indicate that the lack of RB phototoxicity during in vivo tissue repair results from upregulation of prosurvival pathways in tissue cells, oxygen depletion and irradiance‐dependent RB photochemistry.     

Phototherapeutic Effect of Low‐Level Laser on Thyroid Gland of Gamma‐Irradiated Rats

One inescapable feature of life on the earth is exposure to ionizing radiation. The thyroid gland is one of the most sensitive organs to gamma‐radiation and endocrine disrupters. Low‐level laser therapy (LLLT) has been used to stimulate tissue repair, and reduce inflammation. The aim of this study was to gauge the value of using Helium–Neon laser to repair the damaged tissues of thyroid gland after gamma‐irradiation. Albino rats were used in this study (144 rats), divided into control, gamma, laser, and gamma plus laser‐irradiated groups, each group was divided into six subgroups according to time of treatment (total six sessions). Rats were irradiated once with gamma radiation (6 Gy), and an external dose of laser (Wavelength 632.8 nm, 12 mW, CW, Illuminated area 5.73 cm², 2.1 mW cm^?2, 120 s, 1.4 J, 0.252 J cm^?2) twice weekly localized on thyroid region of the neck, for a total of six sessions. Animals were sacrificed after each session. Analysis included thyroid function, oxidative stress markers, liver function and blood picture. Results revealed improvement in thyroid function, liver function and antioxidant levels, and the blood cells count after LLLT.     

Direct Observation of an Imidoylnitrene: Photochemical Formation of PhC(=NMe)−N and Me−N from 1‐Methyl‐5‐phenyltetrazole

The imidoylnitrene 8 , N‐methyl‐C‐phenylimidoylnitrene, has been generated by laser photolysis of 1‐methyl‐5‐phenyltetrazole 6 at 5 K and characterized by its ESR spectrum (|D/hc|=0.9602, |E/hc|=0.0144 cm^?1). In addition, the triplet excited states of 6 and of 2‐methyl‐5‐phenyltetrazole 11 were also observed by ESR spectroscopy in the 5 K matrices ( 6 : |D/hc|=0.123 cm^?1, E/hc=0.0065 cm^?1, 11 : |D/hc|=0.126 cm^?1, |E/hc|=0.0056 cm^?1). The imidoylnitrene 8 is unstable both thermally (disappearing at 80 K) and photochemically (disappearing on continued irradiation at 266 nm). Methyl(phenyl)carbodiimide is the end product of photolysis.     

Phototherapy on the Treatment of Burning Mouth Syndrome: A Prospective Analysis of 20 Cases

The aim of this study was to report the effect of laser phototherapy (LPT) on the treatment of burning mouth syndrome (BMS). This prospective clinical study reports on preliminary outcomes of twenty volunteers diagnosed with BMS who have undergone the conventional treatment prior to laser phototherapy. LPT consisted of weekly sessions of LPT (660 nm), for a period of 10 weeks. The laser protocol consisted of the following parameters: 40 mW, 10 J cm² and 0.4 J per point, irradiation time of 10 s. In all sessions, the burning intensity was evaluated with a 10 cm Visual Analogue Scale (VAS). The burning intensity evaluation by VAS was performed immediately before and after each LPT session. Nonparametric test of Wilcoxon was used for statistical analysis, considering a significance level of 5%. All volunteers reported reduced burning intensity in all sessions when compared to the previous one and reduction in VAS scores by up to 49% in the last clinical session when compared to the first session. When only the VAS baseline of the first session was compared with the consecutive sessions, there was a statistically significant reduction in VAS scores in almost all sessions. The LPT may be an alternative treatment for the relief of oral burning symptoms in patients with BMS.     

Hydrogel‐Forming and Dissolving Microneedles for Enhanced Delivery of Photosensitizers and Precursors

We present “one‐step application” dissolving and hydrogel‐forming microneedle arrays (MN) for enhanced delivery of photosensitizers/precursors. MN (280 μm) prepared from 20% w/w poly(methylvinylether/maelic acid) and cross‐linked with glycerol by esterification to form hydrogels upon skin insertion, or allowed to dissolve rapidly in skin, were combined with patches containing 19 mg cm^?2 of 5‐aminolevulinic acid (ALA) or meso‐tetra (N‐methyl‐4‐pyridyl) porphine tetra tosylate (TMP) for drug delivery. Both MN types were mechanically robust, with compression forces of 20.0 N only causing height reductions of 14%. Application forces as low as 8.0 N per array allowed >95% of the MN in each array type to penetrate excised porcine skin, with the MN penetrating to approximately 220 μm. MN significantly enhanced transdermal delivery of ALA and TMP in vitro, with the hydrogel‐forming system comparable with the dissolving system for ALA delivery (approximately 3000 nmol cm^?2 over 6 h), but superior for delivery of the much larger TMP molecule (approximately 14 nmol cm^?2 over 24 h, compared to 0.15 nmol cm^?2). As this technology clearly has potential in enhanced photodynamic therapy of neoplastic skin lesions, we are currently planning animal studies, to be followed by preliminary human evaluations. GMP manufacturing scale‐up is ongoing.     

Modeling ionomer swelling dynamics of a sulfonated polyphenylene,pentablock copolymers,and nafion

The water swelling behavior of Nafion, sulfonated poly(phenylene) (sPP), and poly[t‐butyl styrene‐b‐hydrogenated isoprene‐b‐sulfonated styrene‐b‐hydrogenated isoprene‐b‐t‐butyl styrene) was studied in order to understand microscopic molecular interactions. Ionomer swelling was modeled using the Flory‐Rehner relationship to predict solvent‐ionomer interaction parameter (χ ₁₂) and effective number of elastically active chains (n ). Water swollen PBC had a decreasing χ₁₂ from 1.146 to 0.516 when its ion‐exchange capacity (IEC) increased from 1.0 to 2.0. Nafion 117 and sPP χ ₁₂ values were 0.93 and 0.807 at an IEC of 0.91 and 1.8. Polymer water uptake was inversely dependent upon n and IEC or sulfonic acid‐group concentration. The following trend was noted for ionomer type, n , and water uptake: PBC‐2.0 (159 wt % and 7.89e‐4 mol/cm³) > sPP (48.6 wt % and 1.40e‐3 mol/cm³) > Nafion 117 (23 wt % and 1.24e‐3 mol/cm³). The ionomer's Gibb's total free change (ΔG_Tot ) due to water swelling for Nafion 117 was ?15.3 J, sPP was ?28.5 J, and PBC‐2.0 was ?53.2 J. An empirical equation was created to estimate a material's total solubility parameter (δ ); and dispersion (δ_d ), dipolar (δ_p ,), and hydrogen bonding (δ_h ) forces. The δ values for Nafion 117, sPP, and PBC‐2.0 were 19.9 (J/cm³)^1/2, 21.3 (J/cm³)^1/2, and 21.0 (J/cm³)^1/2. Idealized swelling within an ionomer due to solvent. Ion domains are comprised of fixed sulfonated acid groups (? SO₃H) along the polymer's backbone. These functional groups provide interaction sites for molecules to diffusion and swell chains. The total change in free energy ΔG is dominated by ΔG_mix that is attributed to hydrogen bonding and the concentration of elastically active chains n , which directly impacts its chemical potential Δμ . © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 435–443     

Photobiomodulation by Infrared Diode Laser: Effects on Intracellular Calcium Concentration and Nitric Oxide Production of Paramecium

In Paramecium, cilia beating is correlated to intracellular calcium concentration ([Ca²⁺]i) and nitric oxide (NO) synthesis. Recent findings affirm that photobiomodulation (PBM) can transiently increase the [Ca²⁺]i in mammalian cells. In this study, we investigated the effect of both 808 and 980 nm diode laser irradiated with flat‐top hand‐piece on [Ca²⁺]i and NO production of Paramecium primaurelia, to provide basic information for the development of new therapeutic approaches. In the experiments, the laser power in CW varied (0.1; 0.5; 1; and 1.5 W) to generate the following respective fluences: 6.4; 32; 64; and 96 J cm^?2. The 6.4 J cm^?2 did not induce PBM if irradiated by both 808 and 980 nm diode laser. Conversely, the 32 J cm^?2 fluence had no effect on Paramecium cells if irradiated by the 808 nm laser, while if irradiated by the 980 nm laser induced increment in swimming speed (suggesting an effect on the [Ca²⁺]i, NO production, similar to the 64 J cm^?2 with the 808 nm wavelength). The more evident discordance occurred with the 96 J cm^?2 fluence, which had the more efficient effect on PBM among the parameters if irradiated with the 808 nm laser and killed the Paramecium cells if irradiated by the 980 nm laser. Lastly, the 980 nm and 64 or 96 J cm^?2 were the only parameters to induce a release of stored calcium.     

Hybrid phospholipid bilayer coatings for separations of cationic proteins in capillary zone electrophoresis

Protein separations in CZE suffer from nonspecific adsorption of analytes to the capillary surface. Semipermanent phospholipid bilayers have been used to minimize adsorption, but must be regenerated regularly to ensure reproducibility. We investigated the formation, characterization, and use of hybrid phospholipid bilayers (HPBs) as more stable biosurfactant capillary coatings for CZE protein separations. HPBs are formed by covalently modifying a support with a hydrophobic monolayer onto which a self‐assembled lipid monolayer is deposited. Monolayers prepared in capillaries using 3‐cyanopropyldimethylchlorosilane (CPDCS) or n‐octyldimethylchlorosilane (ODCS) yielded hydrophobic surfaces with lowered surface free energies of 6.0 ± 0.3 or 0.2 ± 0.1 mJ m^?2, respectively, compared to 17 ± 1 mJ m^?2 for bare silica capillaries. HPBs were formed by subsequently fusing vesicles comprised of 1,2‐dilauroyl‐sn‐glycero‐3‐phosphocholine or 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine to CPDCS‐ or ODCS‐modified capillaries. The resultant HPB coatings shielded the capillary surface and yielded reduced electroosmotic mobility (1.3–1.9 × 10^?4 cm² V^?1s^?1) compared to CPDCS‐ and ODCS‐modified or bare capillaries (3.6 ± 0.2 × 10^?4 cm² V^?1s^?1, 4.8 ± 0.4 × 10^?4 cm² V^?1s^?1, and 6.0 ± 0.2 × 10^?4 cm² V^?1s^?1, respectively), with increased stability compared to phospholipid bilayer coatings. HPB‐coated capillaries yielded reproducible protein migration times (RSD ≤ 3.6%, n ≥ 6) with separation efficiencies as high as 200 000 plates/m.     

CO2 Fixation into Novel CO2 Storage Materials Composed of 1,2‐Ethanediamine and Ethylene Glycol Derivatives

A new CO₂ fixation process into solid CO₂‐storage materials (CO₂SMs) under mild conditions has been developed. The novel application of amine–glycol systems to the capture, storage, and utilization of CO₂ with readily available 1,2‐ethanediamine (EDA) and ethylene glycol derivatives (EGs) was demonstrated. Typically, the CO₂SMs were isolated in 28.9–47.5 % yields, followed by extensive characterization using ¹³C NMR, XRD, and FTIR. We found that especially the resulting poly‐ethylene‐glycol‐300‐based CO₂SM (PCO₂SM) product could be processed into stable tablets for CO₂ storage; the aqueous PCO₂SM solution exhibited remarkable CO₂ capturing and releasing capabilities after multiple cycles. Most importantly, the EDA and PEG 300 released from PCO₂SM were found to act as facilitative surfactants for the multiple preparation of CaCO₃ microparticles with nano‐layer structure.     

Photodynamic Inactivation of Bacterial and Yeast Biofilms With a Cationic Porphyrin

The efficiency of 5,10,15,20‐tetrakis(1‐methylpyridinium‐4‐yl)porphyrin tetra‐iodide (Tetra‐Py⁺‐Me) in the photodynamic inactivation of single‐species biofilms of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans and mixed biofilms of S. aureus and C. albicans was evaluated. The effect on the extracellular matrix of P. aeruginosa was also assessed. Irradiation with white light up to an energy dose of 64.8 J cm^?2 in the presence of 20 μm of Tetra‐Py⁺‐Me caused significant inactivation in all single‐species biofilms (3–6 log reductions), although the susceptibility was attenuated in relation to planktonic cells. In mixed biofilms, the inactivation of S. aureus was as efficient as in single‐species biofilms but the susceptibility of C. albicans decreased. In P. aeruginosa biofilms, a reduction of 81% in the polysaccharide content of the matrix was observed after treatment with a 20 μm PS concentration and a total light dose of 64.8 J cm^?2. The results show that the Tetra‐Py⁺‐Me causes significant inactivation of the microorganisms, either in biofilms or in the planktonic form, and demonstrate that polysaccharides of the biofilm matrix may be a primary target of photodynamic damage.     

Conducting hydrogels based on semi‐interpenetrating networks of polyaniline in poly(acrylamide‐co‐itaconic acid) matrix: synthesis and characterization

In this work, acrylamide/itaconic acid copolymeric hydrogels are prepared by free radical polymerization initiated by redox initiators of potassium persulfate and N ,N ,N ′,N ′‐tetramethyl ethylene diamine; N ,N ′methylene bisacrylamide was employed as a crosslinking agent. Aniline monomer was absorbed in the network of poly(acrylamide‐co‐itaconic acid) P(AAm‐co‐IA) hydrogel and followed by gamma radiation induced polymerization at room temperature. The novel semi‐interpenetrating network was comprised of linear polyaniline immersed in P(AAm‐co‐IA) matrix. Electrical conductivity of the hydrogels was measured using four‐probe technique. The conductivities for the prepared hydrogels are found to increase from 5.5 × 10^?7 S cm^?1 for P(AAm‐co‐IA) alone to 4.4 × 10^?3 S cm^?1 for semi‐interpenetrating polymer network P(AAm‐co‐IA)/polyaniline. Thus, a new composite hydrogel with good conductive properties also displaying enhanced mechanical strength and pH sensitivity was prepared. Copyright © 2017 John Wiley & Sons, Ltd.     

Syntheses and antitumor activities of polymers containing amino acid and 5‐fluorouracil moieties

The new monomer, 3,6‐endo‐methylene‐1,2,3,6‐tetrahydrophthalimidoethanoyl‐5‐fluorouracil (ETEFU), was synthesized from 5‐fluorouracil (5‐FU) and 3,6‐endo‐methylene‐1,2,3,6‐tetrahydophthalimidoethanoyl chloride (ETEC). Its homopolymer and copolymers with acrylic acid (AA) and vinyl acetate (VAc) were prepared by photopolymerization reactions using 2,2‐dimethoxy‐2‐phenylacetophenone (DMP) as the photoinitiator. The synthesized ETEFU and polymers were identified by FT‐IR, ¹H‐NMR, and ¹³C‐NMR spectra. The contents of ETEFU units in poly(ETEFU‐co‐AA) and poly(ETEFU‐co‐VAc) were 20 and 17 mol%, respectively. The number‐average molecular weights of the synthesized polymers determined by gel permeation chromatography (GPC) were 4,600 to 10,700 g mol⁻¹. In vitro cytotoxicities of samples were evaluated with cancer cell lines [mouse mammary carcinoma (FM3A), mouse leukemia (P388), and human histiocytic lymphoma (U937)] and a normal cell line [mouse liver cells (AC2F)]. Cytotoxicities of 5‐FU and synthesized samples against the cancer cell lines were ranked as follows: ETEFU > poly(ETEFU) > 5‐FU > poly(ETEFU‐co‐AA) > poly(ETEFU‐co‐VAc). The in vivo antitumor activities of poly(ETEFU) and poly(ETEFU‐co‐AA) against Balb/C mice bearing the sarcoma 180 tumor cells were greater than those of 5‐FU at all doses except for the activity of poly(ETEFU) at 0.8 mg/kg. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1589–1595, 1999