Development of novel mucoadhesive gels containing nanoparticle for buccal administration of dexamethasone

Abstract This study aimed to develop promising and innovative mucoadhesive gel systems containing dexamethasone-loaded nanoparticle to increase the effectiveness of treatment for oral precancerous lesions and to reduce side effects. In this respect, a dexamethasone-loaded nanoparticle formulation was prepared by using emulsification/solvent evaporation method. The nanoparticle has high zeta potential (-10.3±0.5 mV), low particle size (218.42±2.1), low polydispersity index (0.070±0.014) and high encapsulation efficiency (95.018±2.982%). To improve the mucosal retention time, the dexamethasone-loaded nanoparticle was dispersed in mucoadhesive gel using gellan gum. The developed gels offered appropriate pH value, high drug content, suitable mechanical and mucoadhesive performance and appropriate viscosity for mucosal administration. All formulations exhibited plastic flow and typical gel-type mechanical spectra after the determined frequency value. The developed formulations exhibited extended drug release as intended for these systems. Cytotoxicity was tested by MTT assay in human epithelioid carcinoma cell (HeLa) in vitro. The MTT assay showed that the blank formulations were non-toxic to cells. It was observed that the bioactivity of the free dexamethasone was potentiated by mucoadhesive gels containing dexamethasone-loaded nanoparticle in HeLa cells. Results from this study indicate that mucoadhesive gels are effective for the local treatment of precancerous lesions. Our findings showed that the developed formulations were worthy of further studies.

Intranasal drug delivery devices are a potential contamination source of airways / Dispositivos intranasais de medicamentos são uma potencial fonte de contaminação das vias aéreas

Background: The use of intranasal drug delivery devices (IDDD) for the treatment of allergic rhinitis (AR) is frequent because they are simple, efficient, and safe, and mainly because they are perceived as low-risk. However, it is speculated that contact between the nasal mucosa and an IDDD may give rise to infections once the nose is colonized by bacteria, and there are currently no proper instructions for IDDD sanitization. The objective of this study was to evaluate the possibility of contamination of an IDDD for topical medication after simulating use in healthy individuals. Methods: The in vitro study consisted of 14 healthy individuals of both sexes, between the ages of 18 and 24 years. Samples were collected immediately after the opening of each IDDD and after simulating use by the subjects. Afterwards, the samples were deposited in tubes and kept in an incubator at 37 °C. After 48 hours, the samples were inoculated on Müller-Hinton agar. Qualitative analyses of the appearance of the samples were performed after 24 and 48 hours, and after 72 hours the presence or absence of bacteria was evaluated macroscopically. Results: After 24 hours of incubation, 21.4% (n = 3) of the samples presented with a turbid appearance and after 48h, 71% (n = 10) of the samples presented with a turbid appearance and positive bacterial growth. Conclusion: The results suggest that IDDDs for topical medications may be important sources of contamination or recontamination of the nasal mucosa of individuals who are being treated for upper respiratory tract conditions. A better understanding of the risks of re-using IDDDs after previous contact with the nasal mucosa will improve guidelines on hygiene procedures and prevention of related risks.

Introdução: O uso de dispositivos intranasais para administração de medicamentos (IDDD) no tratamento da rinite alérgica (AR) é frequente, por serem simples, eficientes e seguros, e principalmente por serem de baixo risco. No entanto, especula-se que o contato entre a mucosa nasal e um IDDD possa causar infecções, uma vez que o nariz é colonizado por bactérias, e atualmente não há instruções adequadas para a higienização do IDDD. O objetivo deste estudo foi avaliar a possibilidade de contaminação de um IDDD para medicação tópica após simulação de uso em indivíduos saudáveis. Métodos: O estudo in vitro foi composto por 14 indivíduos saudáveis, de ambos os sexos, com idades entre 18 e 24 anos. As amostras foram coletadas imediatamente após a abertura de cada IDDD, e após a simulação do uso pelos sujeitos. Posteriormente, as amostras foram depositadas em tubos e mantidas em incubadora a 37 °C. Após 48 horas, as amostras foram inoculadas em ágar Müller-Hinton. As análises qualitativas da aparência das amostras foram realizadas após 24 e 48 horas, e após 72 horas a presença ou ausência de bactérias foi avaliada macroscopicamente. Resultados: Após 24 horas de incubação, 21,4% (n = 3) das amostras apresentaram aparência turva e, após 48h, 71% (n = 10) das amostras apresentaram aparência turva e crescimento bacteriano positivo. Conclusão: Os resultados sugerem que IDDDs para medicações tópicas podem ser importantes fontes de contaminação ou recontaminação da mucosa nasal de indivíduos em tratamento para condições do trato respiratório superior. Uma melhor compreensão dos riscos da reutilização de IDDDs após contato prévio com a mucosa nasal, melhorará as diretrizes sobre procedimentos de higiene e prevenção de riscos relacionados.

Carbohydrate Mouth Rinse Fails to Improve Four-Kilometer Cycling Time Trial Performance.

We investigated if a carbohydrate (CHO) mouth rinse may attenuate global fatigue and improve 4-km cycling time trial (TT4km) performance. After a preliminary session, cyclists (n = 9) performed a TT4km after a CHO or placebo (PLA) mouth rinse. Mean power output, time, and ratings of perceived exertion (RPE) were recorded throughout the TT4km. Twitch interpolation responses (%VA; voluntary activation and ∆Tw; delta peak twitch torque) were compared pre and post TT4km with traditional statistics and effect size (ES) analysis. Time-to-complete the 4 km and mean power output were comparable between CHO (386.4 ± 28.0 s) and PLA (385.4 ± 22.4 s). A lower central (p = 0.054) and peripheral (p = 0.02) fatigue in CHO than in PLA were suggested by an extremely-large ES in %VA (manipulation main effect: p = 0.052, d = 1.18; manipulation-by-time interaction effect: p = 0.08, d = 1.00) and an extremely, very-large ES in ∆Tw (manipulation main effect: p = 0.07, d = 0.97; time-by-manipulation interaction effect: p = 0.09, d = 0.89). The RPE increased slower in CHO than in PLA (p = 0.051; d = 0.7). The apparent reduction in global fatigue (central and peripheral) and RPESLOPE with only one CHO mouth rinse were not translated into improved TT4km performance. Further tests may be required to verify if these likely differences in global fatigue might represent an edge in the short-lasting cycling time trial performance.

Efficacy of azole therapy for tegumentary leishmaniasis: A systematic review and meta-analysis.

BACKGROUND: Several controlled and uncontrolled studies addressing azole antifungal drugs for cutaneous and mucosal leishmaniasis have been published with inconclusive results. We conducted a systematic literature review of studies evaluating the efficacy and toxicity associated with azole therapy for tegumentary leishmaniasis. METHODOLOGY: PRISMA guidelines for systematic reviews and the Cochrane manual were followed, and the review methodology was registered (PROSPERO; CRD42016048668). Sources included the EMBASE, Web of Science, MEDLINE, LILACS, and IBECS databases along with a manual search of references from evaluated studies. Additional resources such as Google Scholar and clinicaltrials.gov were also searched. We included all studies reporting cure rate after cutaneous or mucosal leishmaniasis treatment with systemic azole drugs, regardless of their design. R software was used to estimate global rates of success and adverse events with each drug. The main outcome of interest was clinical cure, defined as complete re-epithelialization of all lesions. RESULTS: A total of 37 studies involving 1259 patients that reported outcomes after fluconazole (9), ketoconazole (14) and itraconazole (15) treatments were included. Only 14 (38%) were randomized controlled trials (RCT). The pooled azole final efficacy rate was 64% (CI95%: 57-70%) for all studies and 60% (CI95%: 50-70%) (p = 0.41) if only RCTs studies were considered. Twenty-four studies were conducted in the Old World and 13 studies in the Americas. The final efficacy rate according to New and Old World were 62% (CI95%: 43-77%) and 66% (CI95%: 58-73%), respectively. The final efficacy rate of azoles according to species were 89% (CI95%: 50-98%) for L. mexicana; 88% for L. infantum (CI95%: 27-99%); 80% for L. donovani; 53% (CI95%: 29-76%) for L. major; 49% for L. braziliensis (CI95%: 21-78%); and 15% (CI95%: 1-84%) for L. tropica. The cure rates were similar among the fluconazole, ketoconazole and itraconazole group arms (p = 0.89), specifically 61% (CI95%: 48-72%), 64% (CI95%: 44-80%) 65% (CI95%: 56-72%), respectively. Adverse events during fluconazole, itraconazole and ketoconazole therapy were reported in 7% (CI95%: 3-14%), 12% (CI95% 8-19%) and 13% (CI95%: 6-29%) of treated patients, respectively, without difference among them (p = 0.35). This systematic review included studies with small samples and both non-comparative and non-randomized studies and the main limitation was the low quality of the available studies. CONCLUSIONS: Available evidence suggests that fluconazole, ketoconazole and itraconazole have similar and modest efficacy rates for tegumentary leishmaniasis treatment. There is insufficient evidence to support the exclusive use of azole therapy as a single agent for leishmaniasis treatment.

Anti-metastatic immunotherapy based on mucosal administration of flagellin and immunomodulatory P10.

Current therapies against malignant melanoma generally fail to increase survival in most patients, and immunotherapy is a promising approach as it could reduce the dosage of toxic therapeutic drugs. In the present study, we show that an immunotherapeutic approach based on the use of the Toll-like receptor (TLR)-5 ligand flagellin (Salmonella Typhimurium FliCi) combined with the major histocompatibility complex class II-restricted P10 peptide, derived from the Paracoccidioides brasiliensis gp43 major surface protein, reduced the number of lung metastasis in a murine melanoma model. Compounds were administered intranasally into C57Bl/6 mice intravenously challenged with syngeneic B16F10-Nex2 melanoma cells, aiming at the local (pulmonary) immune response modulation. Along with a marked reduction in the number of lung nodules, a significant increase in survival was observed. The immunization regimen induced both local and systemic proinflammatory responses. Lung macrophages were polarized towards a M1 phenotype, lymph node cells, and splenocytes secreted higher interleukin-12p40 and interferon (IFN)-γ levels when re-stimulated with tumor antigens. The protective effect of the FliCi+P10 formulation required TLR-5, myeloid differentiation primary response gene 88 and IFN-γ expression, but caspase-1 knockout mice were only partially protected, suggesting that intracellular flagellin receptors are not involved with the anti-tumor effect. The immune therapy resulted in the activation of tumor-specific CD4(+) T lymphocytes, which conferred protection to metastatic melanoma growth after adoptive transfer. Taken together, our results report a new immunotherapeutic approach based on TLR-5 activation and IFN-γ production capable to control the metastatic growth of B16F10-Nex2 melanoma, being a promising alternative to be associated with chemotherapeutic drugs for an effective anti-tumor responses.

Comparison of topical and infiltration anesthesia for orthodontic mini-implant placement.

OBJECTIVE: To compare the acceptability and effectiveness of topical and infiltration anesthesia for placement of mini-implants used as temporary anchorage devices. METHODS: The sample comprised 40 patients, 17 males and 23 females, whose mean age was of 26 years and who were all undergoing orthodontic treatment and in need for anchorage reinforcement. Mini-implants were bilaterally placed in the maxilla of all individuals, with infiltration anesthesia on one side and topical anesthesia on the other. These 40 patients completed two questionnaires, one before and another after mini-implant placement, and pain was measured through a visual analog scale (VAS). The data collected were analyzed using descriptive statistics and the measurements of pain were compared by means of Mann-Whitney non-parametric test. RESULTS: It was found that 60% of patients felt more comfortable with the use of topical anesthesia for mini-implant placement; 72.5% of patients described the presence of pressure during placement of the anchorage device as the most unpleasant sensation of the entire process; 62.5% of patients felt more pain with the use of topical anesthesia. CONCLUSION: It was concluded that patients had less pain with the use of infiltration anesthesia, and also preferred this type of anesthetic.

Comparison of topical and infiltration anesthesia for orthodontic mini-implant placement

Objective: To compare the acceptability and effectiveness of topical and infiltration anesthesia for placement of mini-implants used as temporary anchorage devices. Methods: The sample comprised 40 patients, 17 males and 23 females, whose mean age was 26 years old and who were all undergoing orthodontic treatment and in need for anchorage reinforcement. Mini-implants were bilaterally placed in the maxilla of all individuals, with infiltration anesthesia on one side and topical anesthesia on the other. These 40 patients completed two questionnaires, one before and another after mini-implant placement and pain was measured through a visual analog scale (VAS). The data collected were analyzed using descriptive statistics and the measurements of pain were compared by means of the non-parametric test of Mann-Whitney. Results: It was found that 60% of patients felt more comfortable with the use of topical anesthesia for mini-implant placement; 72.5% of patients described the occurrence of pressure during placement of the anchorage device as the most unpleasant sensation of the entire process; 62.5% of patients felt more pain with the use of topical anesthesia. Conclusion: It was concluded that patients had less pain with the use of infiltration anesthesia, and also preferred this type of anesthetic. .

Objetivo: comparar a aceitabilidade e a efetividade do uso de anestésico tópico e anestésico infiltrativo para inserção de mini-implantes ortodônticos, utilizados como dispositivos de ancoragem temporária. Métodos: foram selecionados 40 pacientes, sendo 17 do sexo masculino e 23 do sexo feminino, com idade média de 26 anos, todos em tratamento ortodôntico e necessitando de reforço de ancoragem. Em todos os indivíduos foram instalados mini-implantes bilateralmente em maxila, sendo em um dos lados com anestesia infiltrativa e do lado oposto com anestesia tópica. Esses 40 pacientes responderam dois questionários, sendo um pré- e outro pós-operatório, e foram obtidos índices de dor por meio da escala visual análoga (VAS). Os dados coletados foram analisados por meio de estatística descritiva e os índices de dor foram comparados por meio do teste não-paramétrico de Mann-Whitney. Resultados: verificou-se que 60% dos pacientes se sentiram mais confortáveis com a utilização de anestesia tópica para a inserção dos mini-implantes; 72,5% dos pacientes apontaram a pressão durante a inserção do dispositivo de ancoragem como a sensação mais desagradável de todo o processo; 62,5% dos pacientes sentiram mais dor com o uso de anestesia tópica. Conclusão: concluiu-se que os pacientes apresentaram menor índice de dor com o uso de anestesia infiltrativa e que, também, preferiram esse tipo de anestésico. .

Monocyte-derived macrophages from Zebu (Bos taurus indicus) are more efficient to control Brucella abortus intracellular survival than macrophages from European cattle (Bos taurus taurus).

Brucellosis is one of the most important zoonotic diseases in the world. Considering its strict zoonotic nature, understanding of the pathogenesis and immunity of Brucella spp. in natural animal hosts is essential to prevent human infections. Natural resistance against brucellosis has been demonstrated in cattle, and it is associated with the ability of macrophages to prevent intracellular replication of Brucella abortus. Identification of breeds that are resistant to B. abortus may contribute for controlling and eradicating brucellosis in cattle. This study aimed to compare macrophages from Nelore (Bos taurus indicus) or Holstein (Bos taurus taurus) regarding their resistance to B. abortus infection. Macrophages from Nelore were significantly more efficient in controlling intracellular growth of B. abortus when compared to Holstein macrophages even under intralysosomal iron restricting conditions. Furthermore, Nelore macrophages had higher transcription levels of inducible nitric oxide synthase (iNOS) and TNF-α at 12h post-infection (hpi) and higher levels of IL-12 at 24 hpi when compared to Holstein macrophages. Conversely, Holstein macrophages had higher levels of IL-10 transcripts at 24 hpi. Macrohages from Nelore also generated more nitric oxide (NO) in response to B. abortus infection when compared to Holstein macrophages. In conclusion, cultured Nelore macrophages are more effective in controlling intracellular replication of B. abortus, suggesting that Nelore cattle is likely to have a higher degree of natural resistance to brucellosis than Holstein.

Single dose adenovirus vectored vaccine induces a potent and long-lasting immune response against rabbit hemorrhagic disease virus after parenteral or mucosal administration.

Rabbit hemorrhagic disease virus (RHDV) is the etiological agent of a lethal and contagious disease of rabbits that remains as a serious problem worldwide. As this virus does not replicate in cell culture systems, the capsid protein gene has been expressed in heterologous hosts or inserted in replication-competent viruses in order to obtain non-conventional RHDV vaccines. However, due to technological or safety issues, current RHDV vaccines are still prepared from organs of infected rabbits. In this work, two human type 5 derived replication-defective adenoviruses encoding the rabbit hemorrhagic disease virus VP60 capsid protein were constructed. The recombinant protein was expressed as a multimer in mouse and rabbit cell lines at levels that ranged from approximately 120 to 160 mg/L of culture. Mice intravenously or subcutaneously inoculated with a single 10(8) gene transfer units (GTU) dose of the AdVP60 vector (designed for VP60 intracellular expression) seroconverted at days 7 and 14 post-immunization, respectively. This vector generated a stronger response than that obtained with a second vector (AdVP60sec) designed for VP60 secretion. Rabbits were then immunized by parenteral or mucosal routes with a single 10(9)GTU dose of the AdVP60 and the antibody response was evaluated using a competition ELISA specific for RHDV or RHDVa. Protective hemagglutination inhibition (HI) titers were also promptly detected and IgG antibodies corresponding with inhibition percentages over 85% persisted up to one year in all rabbits, independently of the immunization route employed. These levels were similar to those elicited with inactivated RHDV or with VP60 obtained from yeast or insect cells. IgA specific antibodies were only found in saliva of rabbits immunized by intranasal instillation. The feasibility of VP60 production and vaccination of rabbits with replication-defective adenoviral vectors was demonstrated.