Mucoadhesive Microspheres of Maraviroc and Tenofovir Designed for Pre-Exposure Prophylaxis of HIV-1: An in vitro Assessment of the Effect on Vaginal Lactic Acid Bacteria Microflora.

PURPOSE: To formulate and evaluate microspheres of the antiretroviral drugs maraviroc and tenofovir intended for a candidate vaginal microbicide and assess its effect on the vaginal lactic acid bacteria microflora. METHODS: Ionic gelation technique was used to formulate maraviroc and tenofovir microspheres with subsequent characterization. The effect of varying concentrations of the polymer, crosslinking agent and the curing time on the outcome variables viz: particle size, mucoadhesion and encapsulation efficiency were investigated. Lactic acid bacteria were isolated from the vagina of healthy women using standard microbiologic methods. The analysis of their 16S rRNA sequence data identified Lactobacillus fermentum and Enterococcus faecalis strains which were assigned GenBank accession numbers. The efficacy of the microspheres on HIV-1BaL strain was evaluated using TZM-bl indicator cells. RESULTS: The optimal maraviroc and tenofovir microspheres had particle sizes of (434.82 µm and 456.18 µm), mucoadhesion of (93.3% and 90%) and encapsulation efficiency (92.80% and 78.9%) respectively. Maraviroc release kinetics followed a zero-order model and tenofovir was released via Higuchi model. The assay of a 1 mg/mL suspension of the microspheres on the strains of Lactobacillus fermentum and Enterococcus faecalis showed a viability of 93.9% and 89.7%, respectively. There was a statistically significant difference between the mean absorbance readings of the test agent and that of the positive control (P = 0.001). The microspheres elicited a progressive decline in HIV infectivity until at a concentration of 1 µg/mL. CONCLUSION: The antiretroviral drugs loaded in the microspheres, had good mucoadhesion which is a potential for prolonged residence time in the vagina. The antiretroviral drugs were adequately released from the microspheres and showed efficacy against the HIV-1 BaL virus strain. There was no significant disruption in the growth of the lactic acid bacteria which constitute valuable bacteria microflora of the vagina.

"Their place is beyond the town's border": A qualitative exploration of stigma associated with tuberculosis in rural and urban areas of Lagos, Nigeria.

Tuberculosis (TB) remains a major public health challenge in Nigeria with a minimum yield of various TB control efforts due to sociocultural determinants of health including TB-associated stigma. Therefore, to achieve the Sustainable Development Goal targets for TB control, an understanding and reduction in TB-associated stigma is necessary. The study aims to explore the perspective of community members and investigate the possible ways of mitigating TB-associated stigma in rural and urban areas in Lagos State, Nigeria. Eight focus group discussions (FGD) were conducted among eight homogenous groups of participants living in the community in rural and urban areas of Lagos state who were stratified by gender, between July and November 2017. Analysis of data was done using the modified grounded theory. A total of 86 participants took part in the FGDs. There were various stigmatising behaviours towards people infected with TB in rural and urban communities studied. This includes: Not willing to eat with people suffering from TB, withdrawal from TB patients in social gatherings, verbal abuse of TB patients and refusing to visit their houses because of their illness. There were also misconceptions about the cause of TB in our study which includes spiritual attack, ingestion of cat hair and inhalation of dust. However, participants in the study believed that mitigating the effect of TB-associated stigma will require adequate community education on TB, provision of financial and emotional support to the patients, as well as the involvement of community leaders in TB control activities and stigma reduction interventions. TB-associated stigma exists in rural and urban communities, with a lack of appropriate knowledge of TB and fear of infection as a major determinant in rural and urban areas respectively. Health education and sensitisation about TB, with community leaders as champions could help to mitigate the effect of TB-associated stigma.

Development and evaluation of mucoadhesive bigel containing tenofovir and maraviroc for HIV prophylaxis.

BACKGROUND: Sexual transmission of HIV is the most common means of acquiring the disease. Topical microbicides have been investigated to prevent transmission. This study will use a specific entry inhibitor, maraviroc, and a nucleotide reverse transcriptase inhibitor (NRTI), tenofovir, a dual combination which will provide a synergist effect that can enhance the efficacy of HIV microbicides via a mucoadhesive dual compartment bigel. Bigel formulation via hydrogel organogel linkages were developed and evaluated for their physicochemical characteristics, safety, and anti-HIV efficacy. In vitro diffusion studies were performed with Franz diffusion cells having effective diffusion surface area of 1.76cm2 and receiver chamber volume of 15mL. RESULT: The bigel formulations showed a viscosity ranging from 14179 to 14560 cPs and had a good spreadability and acidic pH in the range of 4.0 ± 0.34 to 5.2 ± 0.18. The bigel formulations showed good anti-HIV activity at a concentration of 0.1 µg/mL. The in vitro release study of maraviroc from the bigel formulations showed a release rate ranging from 2.675 to 3.838 µg/cm2/min½ while the release rate for tenofovir ranged from 3.475 to 3.825 µg/cm2/min½. The bigel formulations were non-toxic to the human vagina as there was < 1 log10 change in Lactobacilli crispatus viability. CONCLUSION: This study successfully developed a dual compartment bigel containing maraviroc and tenofovir. BG C was found to be stable and safe towards vaginal and rectal epithelium, and it actively prevented HIV transmission. This bigel has the potential for long-term pre-exposure prophylaxis prevention of HIV transmission.

Exposure of Allium cepa root cells to zidovudine or nevirapine induces cytogenotoxic changes.

Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p=0.004), but not nevirapine dose (p=0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.

Prevalence and risk factors of asymptomatic bacteriuria among pregnant Nigerians infected with HIV.

OBJECTIVE: There are conflicting report on the association of HIV infection and asymptomatic bacteriuria (ASB). Most of these studies were from areas with low HIV burden. This study determined the prevalence and risk factors of ASB in HIV positive pregnant women. METHODS: A cross sectional study among HIV positive pregnant women seen at a large PMTCT clinic in Lagos Nigeria. The women were evaluated for ASB at first clinic attendance. Blood samples were also collected for viral load, CD4 count and hemoglobin levels assessment. Data were managed with SPSS for windows version 19. RESULTS: 102 (18.1%) women out of 563 studied were found positive for asymptomatic bacteriuria. Ninety-seven (95.1%) of the positive samples yielded single bacterial isolates. Escherichia coli (44.3%) and Proteus mirabilis (21.6%) were the most common bacterial isolates. Previous urinary tract infection (OR: 4.3), HIV-1 RNA greater than 10,000 copies/ml (OR: 3.9), CD4 count <200 cells/mm3 (OR: 1.4) and maternal hemoglobin <11 g/dl (OR: 1.4) were factors significantly associated with ASB after controlling for possible confounders. CONCLUSION: ASB is common in HIV positive pregnant women in our environment and is associated with previous UTI, high viral load, low CD4 count and maternal hemoglobin <11 g/dl.

Incidence of and socio-biologic risk factors for spontaneous preterm birth in HIV positive Nigerian women.

BACKGROUND: Recent studies have identified HIV as a leading contributor to preterm delivery and its associated morbidity and mortality. However little or no information exists in our sub-region on this subject. Identifying the factors associated with preterm delivery in HIV positive women in our country and sub-region will not only prevent mother to child transmission of HIV virus but will also reduce the morbidity and mortality associated with prematurity and low birth weight. This study was designed to determine the incidence and risk factors for preterm delivery in HIV positive Nigerians. METHOD: The required data for this retrospective study was extracted from the data base of a cohort study of the outcome of prevention of mother to child transmission at the Nigerian Institute of Medical Research, Lagos. Only data of women that met the eligibility of spontaneous delivery after 20 weeks of gestation were included. Ethical approval was obtained from the Institution's Ethical Review Board. RESULTS: 181 women out of the 1626 eligible for inclusion into the study had spontaneous preterm delivery (11.1%). The mean birth weight was 3.1 ± 0.4 kg, with 10.3% having LBW. Spontaneous preterm delivery was found to be significantly associated with unmarried status (cOR: 1.7;1.52-2.57), baseline CD4 count <200 cells/mm(3) (cOR: 1.8; 1.16-2.99), presence of opportunistic infection at delivery (cOR: 2.2;1.23-3.57), multiple pregnancy (cOR 10.4; 4.24 - 26.17), use of PI based triple ARV therapy (eOR 10.2; 5.52 - 18.8) in the first trimester (cOR 2.5; 1.77 - 3.52) on univariate analysis. However after multivariate analysis controlling for potential confounding variables including low birth weight, only multiple pregnancy (aOR: 8.6; CI: 6.73 - 12.9), presence of opportunistic infection at delivery (aOR: 1.9; CI: 1.1 - 5.7), and 1st trimester exposure to PI based triple therapy (aOR: 5.4; CI: 3.4 - 7.8) retained their significant association with preterm delivery. CONCLUSION: The spontaneous preterm delivery rate among our cohort was 11.1%. HIV positive women with multiple pregnancies, symptomatic HIV infection at delivery and first trimester fetal exposure to PI based triple therapy were found to be at risk of spontaneous preterm delivery. Early booking and non-use of PI based triple therapy in the first trimester will significantly reduce the risk of preterm delivery.