The influence of polysaccharide coating on the physicochemical parameters and cytotoxicity of silica nanoparticles for hydrophilic biomolecules delivery

The present work reports the effect of polysaccharides (chitosan and sodium alginate) on silica nanoparticles (SiNP) for hydrophilic molecules delivery taking insulin as model drug. The influence of tetraethyl orthosilicate (TEOS) and homogenization speed on SiNP properties was assessed by a 22 factorial design achieving as optimal parameters: 0.43 mol/L of TEOS and homogenization speed of 5000 rpm. SiNP mean particle size (Z-Ave) was of 256.6 nm and polydispersity index (PI) of 0.218. SiNP coated with chitosan (SiNP-CH) or sodium alginate (SiNP-SA) increased insulin association efficacy; reaching 84.6% (SiNP-SA) and 90.8% (SiNP-CH). However, coated SiNP released 50%–60% of the peptide during the first 45 min at acidic environment, while uncoated SiNP only released 30%. Similar results were obtained at pH 6.8. The low Akaike’s (AIC) values indicated that drug release followed Peppas model for SiNP-SA and second order for uncoated SiNP and SiNP-CH (pH 2.0). At pH 6.8, the best fitting was Boltzmann for Ins-SiNP. However, SiNP-CH and SiNP-SA showed a first-order behavior. Cytotoxicity of nanoparticles, assessed in Caco-2 and HepG2 cells, showed that 100 to 500 µg/mL SiNP-CH and SiNP-SA slightly decreased cell viability, comparing with SiNP. In conclusion, coating SiNP with selected polysaccharides influenced the nanoparticles physicochemical properties, the insulin release, and the effect of these nanoparticles on cell viability.This research was supported by the Fundação para a Ciência e Tecnologia (FCT, Portugal), by grating PhD scholarships SFRH/BD/60640/2009 (T. Andreani), SFRH/BD/80335/2011 (J.F. Fangueiro) and SFRH/BD/111274/2015 (P.M.V. Fernandes), and funded projects UID/AGR/04033/2019 (CITAB), and M-ERANET/0004/2015-PAIRED (Partnership Agreement PT2020).info:eu-repo/semantics/publishedVersio

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

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

Client needs and satisfaction in an HIV facility

Health care evaluation serves the purpose of monitoring the quality of health care provided by Health Care Providers (HCP), so that health care services can be provided most effectively and efficiently. Patient satisfaction studies are widely used to assess the quality of outpatient care. A client satisfaction study was conducted at an HIV health care facility in Sydney, Australia during 2007-2008. There were three objectives: 1.) To validate a questionnaire for future determination of client satisfaction in HIV health care facilities. 2.) To identify the levels of satisfaction of clients, and investigate any dissatisfaction and unmet needs towards HIV health care. 3.) To provide recommendations for improving client satisfaction levels in HIV health care. This research used a mixed method approach and consisted of two phases. The first phase was a quantitative survey conducted with 166 clients (both HIV positive and negative) at Albion Street Centre (ASC) using a newly-devised questionnaire. Clients were asked to answer demographic questions, rate their levels of satisfaction with each aspect and each HCP category, and provide suggestions for improvement. Quantitative statistical analysis was conducted to obtain a general view of client satisfaction levels. Dissatisfaction and unmet needs of clients were then investigated in-depth in the second phase of the research through qualitative face-to-face semi-structured interviews. Twenty-two clients (both HIV positive and negative) at ASC were interviewed individually and asked about their attitudes, perceptions, and experiences towards their HCP and the HIV health care services received. Thematic analysis was used to categorise and interpret the qualitative data. More than 90% of the clients were satisfied with most of the aspects covered in the survey, with a mean overall satisfaction score of 84 out of 100. Clients were most iii satisfied with the “technical quality” and “interpersonal manner” of the HCP, and were least satisfied with “waiting time” and “availability of HCP”. The HCP category with which the clients has the highest level of satisfaction was “nurses” (86%), followed by “psychologists” (84%), then “doctors” (83%). Clients who were HIV negative, had a full time job, visited ASC less frequently, or did not possess any type of Health Care Card were more satisfied with the services overall. No common dissatisfaction or unmet needs towards HIV health care service were identified. “Technical quality of HCP” and “the relationship with HCP” were the two most important determinants of client satisfaction, which outweighed the inconvenience contributed by the poor availability of HCP and the location of ASC. The maintenance of “confidentiality/privacy” was shown to be fundamental in HIV health care facilities. The multi-disciplinary nature of ASC increased the degree of convenience and satisfaction level among clients. Suggestions for improvement in client satisfaction levels include increasing the attractiveness of the physical environment and the variety of educational reading materials in the waiting area; introducing beverages, and encouraging clients to be involved in their treatment decisions. Health care administrative staff in particular are reminded not to neglect the importance of the availability of HCP, accessibility, and physical environment when establishing a new HIV health care facility. The mixed method approach (quantitative survey and qualitative interviews) proved beneficial. It increased the validity of the findings by assessing client satisfaction levels using more than one method. This enabled clarification of ambiguities noted in the initial survey through probes used in the interviews, and also allowed investigation of the determinants of client satisfaction through understanding their experiences in HIV health care. Future client satisfaction studies would benefit from using this approach

Meloidogyne paranaensis e Meloidogyne exigua em lavouras cafeeiras da região Sul de Minas Gerais

The cities in the South of Minas Gerais, which is the main coffee producer region in Brazil, would face a serious risk of productivity loss if more aggressive root-knot nematodes species, such as Meloidogyne paranaensis. In order to prevent the dissemination of this nematode, it is necessary to know the occurrence outbreaks and distribution of Meloidogyne spp. in this region. Then, objective was to investigate Coffea arabica plantations of some coffee-producing cities in the South of Minas Gerais by root sampling, diagnosis and mapping of outbreaks. The total of 162 samples was calculated according to the planting area and coffee production in the production areas in some cities. The root-knot nematodes were found in 32.7% of them. The species M. exigua in 90.5%, and M. paranaensis in 9.5% of the detections. The occurrence of M. exigua and M. paranaensis was observed in the cities sampled, except Guaranésia, where no root-knot nematode was present. Esterase phenotypes E1 and E2 were found in M. exigua populations, highlighting the E2 phenotype in most cities (Guaxupé, Monte Belo, Monte Santo de Minas, Muzambinho and São Pedro da União). M. paranaensis (P1 phenotype) was detected in Coqueiral and Alpinópolis causing plant mortality. This suggest that is necessary the use of phytossanitary approaches.Os municípios da Região Sul do Estado de Minas Gerais, maior região produtora de café no Brasil, enfrentam um sério risco de perda na produtividade se espécies dos nematoides das galhas mais agressivas ao cafeeiro, como Meloidogyne paranaensis, estiverem presentes. Para a prevenção da disseminação desse nematoide é necessário conhecer os focos de ocorrência e a distribuição de Meloidogyne spp. nessa Região. Diante do exposto, este trabalho objetivou investigar lavouras cafeeiras de alguns municípios produtores de café do Sul de Minas Gerais por meio da amostragem de raízes, diagnóstico e mapeamento dos focos. O número de amostras foi calculado de acordo com a área de plantio e a produção de café do município. De um total de 165 amostras coletadas, foi constatado o nematóide das galhas em 43,03% delas, sendo identificadas as espécies Meloidogyne exigua em 92,95% e M. paranaensis em 4,22% das detecções e também 2,81% de amostras com populações de M. exigua e M. paranaensis em mistura. A ocorrência de M. exigua e M. paranaensis se deu nos municípios analisados, exceto em Guaranésia, em que nenhum nematoide das galhas estava presente. Os fenótipos E1 e E2 da esterase foram encontrados em M. exigua, se destacando o fenótipo E2 na maioria dos municípios (Guaxupé, Monte Belo, Monte Santo de Minas, Muzambinho e São Pedro da União). M. paranaensis (fenótipo P1) foi detectado parasitando cafeeiros nos municípios de Alpinópolis e Coqueiral, causando intenso depauperamento e morte das plantas. Isso sugere a necessidade da adoção de medidas de contenção da doença na região

Erratum to: The study of cardiovascular risk in adolescents – ERICA: rationale, design and sample characteristics of a national survey examining cardiovascular risk factor profile in Brazilian adolescents

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