In vitro analysis regarding the safety of components used in a film-based therapeutic system loaded with meglumine antimoniate and its activity toward Leishmania major experimental infections: a preliminary study.

Owing to its biocompatibility properties and its ability to promote the scar healing process, chitosan is employed in tissue engineering for the manufacture of formulations. To control the characteristic skin ulcers of cutaneous leishmaniasis (CL), the use of a biopolymeric system that favors the scar healing process and releases an active agent such as meglumine antimoniate may be a better option. For these reasons, here we analyzed the cytotoxic capabilities of excipients [medium molecular weight chitosan (MMWC), lactic acid (LA) and polyvinylpyrrolidone (PVP)], used for the formulation of a film-based therapeutic system that releases meglumine antimoniate and were evaluated on human macrophages [monocyte-derived macrophages (MDMs)], L929 fibroblasts and parasites (Leishmania major promastigotes and intracellular amastigotes). The ability of excipients to modulate the cytokines production involved in the scar healing process was compared with film-based therapeutic system. The efficiency of a film-based therapeutic system loaded with meglumine antimoniate was compared with conventional formulation (Albiventriz(®)). We found that MMWC was toxic for two parasite forms. In contrast, measurement of interleukin levels did not show any evidence of preferential secretion as a side effect of treating human macrophages with MMWC. Finally, the efficiency of a polymeric film-based therapeutic system that was loaded with meglumine antimoniate could not be determined due to the high degree of toxicity observed in infected MDMs; moreover, these compounds do not induce any apparent immunomodulatory effects. Our findings suggest that the final concentrations of each excipients (MMWC, LA and PVP) that were used in the polymeric film were suitable vehicles for active pharmaceutical compound delivery and did not selectively affect (enhancing or diminishing immune activity) macrophages.

Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa.

The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized.

Anaphylactic reaction induced by a polysulfone/polyvinylpyrrolidone membrane in the 10th session of hemodialysis with the same dialyzer.

The majority of severe hypersensitivity reactions in hemodialysis patients have occurred due to sensitization to ethylene oxide or to nonbiocompatible membrane dialyzers. The use of polysulfone dialyzers rarely causes hypersensitivity reactions. In the present study, we describe a case of severe life-threatening reactions induced by polysulfone dialyzers (from different manufacturers subjected to a variety of sterilization methods), which occurred after 9 sessions of hemodialysis with the same prescription, exemplifying the complexity of such reactions.

Effect of six tropical tanniferous plant extracts on larval exsheathment of Haemonchus contortus / Efeito de seis extratos de plantas taniníferas tropicais sobre o desembainhamento larvar de Haemochus contortus

Tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. This experiment evaluated the effects of extracts from the leaf and stem of Anadenanthera colubrina, Leucaena leucocephala and Mimosa tenuiflora on larval exsheathment of Haemonchus contortus in vitro and verified the role of tannins in this process. Third-stage larvae of H. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. The extracts were tested at 300 μg.mL–1 and accompanied by controls: phosphate buffer solution (PBS) and polyvinyl polypyrrolidone (PVPP). The larval exsheathment was evaluated for 60 minutes, and the results were subjected to the Kruskal-Wallis test (p < 0.05). The six extracts blocked larval exsheathment. After PVPP addition, a tannin inhibitor, the exsheathment percentage was similar to the PBS (p > 0.05), except for L. leucocephala and M. tenuiflora leaf extracts. However, pre-incubation with PVPP of these two extracts significantly changed larval exsheathment when compared to the non-treated extracts (p < 0.05). These results suggest that A. colubrina, L. leucocephala and M. tenuiflora could be useful in gastrointestinal nematode control and that tannins are probably the main compounds involved in the observed effects. However, in vivo and toxicological studies should be conducted.(AU)

Plantas taniníferas representam uma promissora alternativa de controle dos nematóides gastrintestinais de pequenos ruminantes. Esse experimento avaliou in vitro os efeitos dos extratos das folhas e caules de Anadenanthera colubrina, Leucaena leucocephala e Mimosa tenuiflora sobre o desembainhamento larvar de Haemonchus contortus e verificou o papel dos taninos nesse processo. Larvas de terceiro estádio de H. contortus foram incubadas com 300 μg.mL–1 de extrato por 3 horas e expostas a uma solução de hipoclorito de sódio. O ensaio foi acompanhado por controles: solução salina tamponada com fosfato (PBS) e polivinilpolipirrolidona (PVPP). O desembainhamento larvar foi avaliado durante 60 minutos e os resultados submetidos ao teste Kruskal-Wallis (p < 0,05). Os seis extratos bloquearam o desembainhamento larvar. Após adição de PVPP, um inibidor de taninos, o percentual de desembainhamento foi similar ao PBS (p > 0,05), exceto nos extratos das folhas de L. leucocephala e M. tenuiflora. Entretanto, a pré-incubação desses dois extratos com PVPP alterou significativamente o desembainhamento quando comparado com extratos não-tratados (p < 0,05). Esses resultados sugerem que A. colubrina, L. leucocephala e M. tenuiflora podem ser úteis no controle de nematóides gastrintestinais e que os taninos são provavelmente os principais compostos envolvidos nos efeitos. Contudo, estudos toxicológicos e in vivo são necessários.(AU)

Tolerability and safety of conventional therapy combination with DeMarco formula for infected ischemic diabetic foot.

BACKGROUND: A study has found that major amputations are necessary on 69% of ischemic diabetic foot patients treated with conventional therapy. An uncontrolled study of 31 patients showed that only 33% needed major amputation after treatment with conventional therapy plus De Marco Formula (DMF), a novel formulation of procaine and Polyvinylpyrrolidone. OBJECTIVE: To assess the tolerability and safety of the combination of conventional therapy and De Marco Formula for infected ischemic diabetic foot. METHODS: Adult patients, 10 male/24 female, were treated with the conventional therapy for diabetic foot plus DMF (0.15 ml/kg/day IM) during ten days and then twice a week until healing of the lesions or completion of a 52-day period. Required amputations, lesion areas, adverse events occurrence and clinical laboratory parameters (hemoglobin, blood cell counts, glycosilated hemoglobin, total proteins, creatinine, alanine transaminase and alkaline phosphatase) were determined during the treatment period. RESULTS: Two slight (5.88%) and one moderate (2.94%) adverse events (mainly cutaneous rash) were reported. The last one was reported on the 15th day of treatment and DMF dosing was discontinued by patient's request. Clinical laboratory mean values remained within normal ranges during treatment except for blood leukocyte counts that pathologically elevated at baseline and decreased to normality by treatment end. This study has found that 18.08% of patients (N=6) needed a lower limb amputation with the combined treatments. The standard reported rate in Cuba is 25-29%. Furthermore, a progressive reduction of the mean lesion area from 51.29 cm2 at the beginning to 1.89 cm2 at the end of the treatment (p=0.000001) was observed. CONCLUSION: The treatment with De Marco Formula for 52 days as an adjuvant for the conventional therapy for infected ischemic diabetic foot was well tolerated and safe. These findings are consistent with those of a randomized prospective controlled study performed later.

Clinical evaluation of De Marco formula as an adjunctive therapy for infected ischemic diabetic foot: a prospective randomized controlled trial.

BACKGROUND: De Marco Formula (DMF) is a novel formulation of procaine and PVP. OBJECTIVE: To assess the efficacy and safety of DMF as an adjunctive therapy for infected ischemic diabetic foot in a prospective randomized controlled clinical trial. METHODS: Adult patients, 39 male/ 79 female, were randomly assigned (59 patients/treatment group) to the conventional therapy alone (A) or plus DMF (0, 15 ml/kg .day i.m.) during ten days and them twice a week until healing of the lesions or completion of 52 days (B).The response to the treatment was considered favorable when an amputation was not needed even though a decrease of the wound area or complete healing was not shown. It was considered unfavorable when a major amputation was necessary because of worsening of the lesion (wound spreading to any magnitude greater than the initial one) or the appearance of new wounds in the same leg. RESULTS: Both groups were comparable with regard to age, sex, level of arterial occlusion, type of lesion, anatomic localization of lesions and previous surgical procedures. The cumulative percentage of unfavorable results was significantly lower after treatment B with respect to treatment A (25.4% vs. 45.8%; p= 0.02), for a reduction of 44.5%. Four slight adverse reactions were associated with DMF: vertigo and nausea at the 7th treatment administration (one patient), and headache and tachycardia at the 12th dose (another patient). Blood hemoglobin and leukocyte counts and serum alanine transaminase were not affected. CONCLUSION: The treatment with DMF for 52 days as an adjuvant for the conventional therapy was associated with a lower need for major amputations. It was also well tolerated and safe.

Hidrogéis de PVP e blendas de PVP/polianidridos como potenciais curativos para feridas crônicas / PVP hydrogels and PVP/Polyanhydride blends as potential materials for chronic wounds dressings

Hidrogéis compreendem uma importante classe de materiais poliméricos adequados à aplicação como curativos de feridas e queimaduras. A estrutura tridimensional hidrofílica dos hidrogéis permite que estes mantenham a umidade ideal no leito das feridas, absorvam o exsudato e não causem danos ao novo tecido durante as trocas dos curativos. No caso dos hidrogéis, essas trocas podem ser menos frequentes. Além disso, curativos que auxiliem na remoção de tecidos necrosados e ainda sejam capazes de oferecer tratamentos extras que acelerem o processo de cicatrização são desejáveis. Este trabalho apresenta a produção de materiais à base de hidrogel capazes de auxiliar neste processo de diferentes maneiras. Primeiramente, são apresentados hidrogéis formados a partir de nanofibras de poli(N-vinil-2-pirrolidona) (PVP) produzidas por eletrofiação, seguido da reticulação através da utilização de radiação UV-C ou reação de Fenton. A utilização da eletrofiação como técnica auxiliar na formação dos hidrogéis permitiu o controle da porosidade através da formação de fibras de diferentes diâmetros. A evidência de tal propriedade foi constatada através da produção de materiais que apresentam diferentes perfis de liberação da proteína modelo albumina de soro bovino (BSA). O hidrogel de PVP nanoestruturado foi capaz de liberar e manter a atividade da colagenase, uma importante enzima aplicada no tratamento de feridas via desbridamento enzimático, durante as 48 horas em que foi avaliado. Além disso, hidrogéis bactericidas nanoestruturados foram produzidos a partir de nanocompósitos de PVP e nanopartículas de prata (AgNP) produzidos por eletrofiação. Esses hidrogéis apresentaram propriedades térmicas semelhantes aos hidrogéis sem AgNP, diminuindo, contudo, a sua capacidade de intumescimento. Esses hidrogéis mostraram-se ativos contra bactérias gram-positivas e gram-negativas a partir de 100 ppm de AgNPs. Adicionalmente, foi estudada a formação de um hidrogel modelo composto PVP/AgNP/Imidazol, almejando-se a produção de um material bactericida-fungicida a base de hidrogel. Este hidrogel apresentou atividade conta três espécies de Candida a partir de 500 ppm de imidazol no material. Embora exista a formação de um complexo estável entre AgNP e Imidazol, cálculos teóricos e a constatação da atividade fungicida corroboram com o fato de que derivados imidazólicos podem ser liberados a partir deste hidrogel híbrido. A produção de hidrogéis físicos compostos por blendas de PVP/Polianidridos sintetizados a partir de derivados de hidroxicinamatos e ácido salicílico, capazes de liberar moléculas de interesse biológico quando parcialmente degradados hidroliticamente, também é descrita neste trabalho. Os resultados indicam que interações hidrofóbicas entre a PVP e os polianidridos sintetizados podem ser responsáveis pela formação dos hidrogéis físicos e pela miscibilidade das blendas produzidas. Os hidrogéis físicos de PVP/Polianidridos foram obtidos na forma de filmes por evaporação do solvente. Micro- e nanofibras também foram obtidas por eletrofiação. Desta maneira, o presente trabalho contribui com o desenvolvimento de uma geração de curativos multifuncionais aplicados no tratamento de feridas crônicas e queimaduras

Hydrogels comprise an important class of polymeric materials that finds application as wound and burn dressings. The hydrophilic three-dimensional structure of hydrogels helps to provide the ideal humidity at the wound bed, to remove exsudates and to prevent damages to the new tissue during dressing substitution. Furthermore, these wound dressings are able to remove necrotic tissues and, therefore, capable to offer extra treatments that would benefit the healing processes. This work describes the production of hydrogel based materials that are able to act in wound healing by different ways. First, it is presented hydrogels composed of poly(N-vinyl-2-pyrrolidone) (PVP) nanofibers produced by electrospinning, followed by its crosslinking using UV-C radiation or Fenton reaction. The use of electrospinning in the hydrogel formation allowed porosity control by obtaining fibers of different diameters. This was evidenced by achieving materials that present different release profiles of the model protein bovine serum albumin (BSA). The nanostructured PVP hydrogel was capable of releasing and maintaining collagenase activity during 48 hour of evaluation. This is an important enzyme that find application in wound healing based on enzymatic debridement. Moreover, nanostructured bactericidal hydrogels were produced from PVP and silver nanoparticles (AgNP) composite through electrospinning, resulting in hydrogels with thermal properties similar to those hydrogels without AgNP, decreasing its swelling ability. These hydrogels were active against gram-positives and gram-negatives bacteria starting from 100 ppm of AgNP. In addition, the production of a model hydrogel composed by PVP/AgNP/Imidazole was investigated, aiming at a bactericidal-fungicidal hydrogel based material. This hydrogel was active against three Candida having 500 ppm of imidazole into the structure. In spite of the formation of a stable complex between AgNP and imidazole, theoretic calculations and the observed fungicidal activity corroborate with the fact that imidazoles derivatives can be released from this hybrid hydrogel. Physical hydrogels composed of PVP/Polyanhydrides blends were synthesized from hydroxycinammates derivatives and salicylic acid. These materials which were capable of releasing molecules with biological potential upon hydrolysis, are also described in this work. The results indicate that hydrophobic interactions between PVP and the synthesized polyanhydrides could be responsible for the hydrogel formation and blend miscibility as well. PVP/Polyanhydride physical hydrogels were obtained from cast films. Micro- and nanofibers were also obtained by electrospinning. Thus, the present work contributes with the development of the new generation of smart dressings for wound and burn healing

Cellular and humoral responses to collagen-polyvinylpyrrolidone administered during short and long periods in humans.

Collagen, particularly type I, and its related derivatives have been extensively employed in many areas of pharmacology. The present study was performed to determine the safety of collagen-polyvinylpyrrolidone (collagen-PVP) by in vitro and in vivo studies. Sera and peripheral blood cells from healthy donors without treatment and patients treated with collagen-PVP were evaluated. We observed that the biodrug does not stimulate lymphoproliferation or DNA damage in vitro, nor does it induce human anti-porcine type I collagen or anti-collagen-PVP antibodies in vivo. Furthermore, no hepatic or renal metabolic dysfunctions were observed when collagen-PVP was administered by intradermal or intramuscular routes in short- or long-term treatments. In conclusion, the present work shows that no cellular damage or immunological adverse effects (cellular and humoral) occurred during collagen-PVP treatment, even after more than 400 weeks of consecutive administrations.