Surface engineering of silica nanoparticles for oral insulin delivery: characterization and cell toxicity studies

The present work aimed at studying the interaction between insulin and SiNP surfaced with mucoadhesive polymers (chitosan, sodium alginate or polyethylene glycol) and the evaluation of their biocompatibility with HepG2 and Caco-2 cell lines, which mimic in vivo the target of insulin-loaded nanoparticles upon oral administration. Thus, a systematic physicochemical study of the surface-modified insulin-silica nanoparticles (Ins-SiNP) using mucoadhesive polymers has been described. The surfacing of nanoparticle involved the coating of silica nanoparticles (SiNP) with different mucoadhesive polymers, to achieve high contact between the systems and the gut mucosa to enhance the oral insulin bioavailability. SiNP were prepared by a modified Stöber method at room temperature via hydrolysis and condensation of tetraethyl orthosilicate (TEOS). Interaction between insulin and nanoparticles was assessed by differential scanning calorimetry (DSC), X-ray and Fourier-transform infrared (FTIR) studies. The high efficiency of nanoparticles' coating resulted in more stable system. FTIR spectra of insulin-loaded nanoparticles showed amide absorption bands which are characteristic of α-helix content. In general, all developed nanoparticles demonstrated high biocompatible, at the tested concentrations (50-500 μg/mL), revealing no or low toxicity in the two human cancer cell lines (HepG2 and Caco-2). In conclusion, the developed insulin-loaded SiNP surfaced with mucoadhesive polymers demonstrated its added value for oral administration of proteins

Lipid Nanocarriers for Hyperproliferative Skin Diseases

Hyperproliferative skin diseases (HSD) are a group of diseases that include cancers, pre-cancerous lesions and diseases of unknown etiology that present different skin manifestations in terms of the degree and distribution of the injuries. Anti-proliferative agents used to treat these diseases are so diverse, including 5-aminolevulinic acid, 5-fluorouracil, imiquimod, methotrexate, paclitaxel, podophyllotoxin, realgar, and corticosteroids in general. These drugs usually have low aqueous solubility, which consequently decreases skin permeation. Thus, their incorporation in lipid nanocarriers has been proposed with the main objective to increase the effectiveness of topical treatment and reduce side effects. This manuscript aims to describe the advantages of using lipid nanoparticles and liposomes that can be used to load diversity of chemically different drugs for the treatment of HSD. Keywords: lipid nanoparticles; liposomes; hyperproliferative skin diseases; antiproliferative drugs; skin cance

Cultura organizacional e o bem-estar dos terapeutas ocupacionais Portugueses

Mestrado em Gestão e Avaliação de Tecnologias em SaúdeO comportamento individual e organizacional são influenciados pela cultura organizacional que configura as formas distintas de expressão e de interação social, que explicam hábitos, costumes e crenças, partilhados pelos membros do mesmo grupo. O presente estudo tem como objetivo principal verificar se a cultura organizacional influencia o bem-estar no trabalho percecionado pelos terapeutas ocupacionais. Pretende-se ainda perceber se as características pessoais e profissionais destes profissionais de saúde, influenciam o seu Bem-Estar no Trabalho. Por último, pretende-se identificar a dimensão que mais contribui para o Bem-Estar no Trabalho. Para a recolha de dados foi realizada por meio de um questionário online constituído por duas secções: a primeira incluiu o Organizacional Culture Assessment Instrument (OCAI) e a segunda, o questionário Bem-Estar no Trabalho para Profissionais de Saúde (BET-Prof.Saúde). A análise dos dados obtidos foi realizada através de análise estatística descritiva de tendência central, por meio do cálculo de frequências, percentagens, médias e desvio padrão, de modo a poder-se caracterizar a amostra e de testes paramétricos (T-Student, Correlação de Spearman, Oneway A-Nova). Foi ainda utilizada a Regressão Linear para análise do modelo de Bem-Estar no Trabalho. Obteve-se uma amostra de 147 participantes, dos quais 88% eram do sexo feminino e 22% do sexo masculino, com idade compreendida entre os 22 e os 63 anos (m=35,20; ± dp=9,648). Tendo em conta os resultados obtidos, concluiu-se que a cultura organizacional, mais precisamente as culturas de Clã e Adocrática, estão associadas positivamente a melhores níveis de Bem-Estar no Trabalho e que o inverso acontece quando predominam as culturas Hierárquica e de Mercado. As dimensões Engagement, Suporte Social e Clima de Equipa, podem ser influenciadas pelas características profissionais dos indivíduos (local de trabalho, tipo de contrato e função de chefia) e são as que mais se relacionam de forma positiva e significativa com o Bem-Estar no Trabalho.ABSTRACT - Individual and organizational behavior are influenced by the organizational culture that shapes the different forms of expression and social interaction that explain habits, customs, and beliefs shared by members of the same group. The main objective of this study is to verify if the organizational culture influences the well-being of work perceived by the occupational therapists. It is also intended to understand if the personal and professional characteristics of these health professionals influence their well-being at work. Finally, it is intended to identify the dimension that contributes most to Well-being at Work. Data collection was done through an online questionnaire consisting of two sections: the first included the Organizational Culture Assessment Instrument (OCAI) and the second, the questionnaire Bem-Estar no Trabalho para Profissionais de Saúde (BET-Prof.saúde). The analysis of the data obtained was performed through a descriptive statistical analysis of central tendency, by means of the calculation of frequencies, percentages, means and standard deviation, in order to be able to characterize the sample and of parametric tests (T-Student, Spearman Correlation, Oneway A-Nova). Linear Regression was also used to analyze the well-being model at work. A sample of 147 participants was obtained, of which 88% were female and 22% male, aged between 22 and 63 years (m = 35,20; ± DP = 9,648). Considering the results obtained, it was concluded that the organizational culture, more precisely the cultures of Clã and Adhocratic, is positively associated with better levels of well-being at work and that the opposite occurs when Hierarchical and Market cultures predominate. The Engagement, Social Support, and Team Climate dimensions can be influenced by the individual’s professional characteristics (workplace, type of contract, and leadership role) and are the ones that are most positively and significantly related to Well-being at work.N/

Surface engineering of silica nanoparticles for oral insulin delivery: characterization and cell toxicity studies

The present work aimed at studying the interaction between insulin and SiNP surfaced with mucoadhesive polymers (chitosan, sodium alginate or polyethylene glycol) and the evaluation of their biocompatibility with HepG2 and Caco-2 cell lines, which mimic in vivo the target of insulin-loaded nanoparticles upon oral administration. Thus, a systematic physicochemical study of the surface-modified insulin-silica nanoparticles (Ins-SiNP) using mucoadhesive polymers has been described. The surfacing of nanoparticle involved the coating of silica nanoparticles (SiNP) with different mucoadhesive polymers, to achieve high contact between the systems and the gut mucosa to enhance the oral insulin bioavailability. SiNP were prepared by a modified Stöber method at room temperature via hydrolysis and condensation of tetraethyl orthosilicate (TEOS). Interaction between insulin and nanoparticles was assessed by differential scanning calorimetry (DSC), X-ray and Fourier-transform infrared (FTIR) studies. The high efficiency of nanoparticles' coating resulted in more stable system. FTIR spectra of insulin-loaded nanoparticles showed amide absorption bands which are characteristic of α-helix content. In general, all developed nanoparticles demonstrated high biocompatible, at the tested concentrations (50-500 μg/mL), revealing no or low toxicity in the two human cancer cell lines (HepG2 and Caco-2). In conclusion, the developed insulin-loaded SiNP surfaced with mucoadhesive polymers demonstrated its added value for oral administration of proteins

Preparation and characterization of PEG-coated silica nanoparticles for oral insulin delivery

The present study reports the production and characterization of PEG-coated silica nanoparticles (SiNP-PEG) containing insulin for oral administration. High (PEG 20,000) and low (PEG 6000) PEG molecular weights were used in the preparations. SiNP were produced by sol gel technology followed by PEG adsorption and characterized for in vitro release by Franz diffusion cells. In vitro permeation profile was assessed using everted rat intestine. HPLC method has been validated for the determination of insulin released and permeated. Insulin secondary structure was performed by circular dichroism (CD). Uncoated SiNP allowed slower insulin release in comparison to SiNP PEG. The coating with high molecular weight PEG did not significantly (p>0.05) alter insulin release. The slow insulin release is attributed to the affinity of insulin for silanol groups at silica surface. Drug release followed second order kinetics for uncoated and SiNP PEG at pH 2.0. On the other hand, at pH 6.8, the best fitting was first-order for SiNP PEG, except for SiNP which showed a Boltzmann behavior. Comparing the values of half-live, SiNP PEG 20,000 showed a faster diffusion followed by Si-PEG 6000 and SiNP. CD studies showed no conformational changes occurring after protein release from the nanoparticles under gastrointestinal simulated conditions. (C) 2014 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP