Systematic study of liposomes composition towards efficient delivery of plasmid DNA as potential application of dermal fibroblasts targeting.

The use of non-viral DNA vectors to topically treat skin diseases has demonstrated a high potential. However, vectors applied on the skin face extracellular barriers including the stratum corneum and intracellular barriers such as the endosomal escape and the nuclear targeting of the plasmid DNA. The aim of this study was to develop a formulation suitable for dermal application and effective for delivering plasmid DNA into cells. Different formulations were prepared using different cationic lipids (DOTAP, DC-Chol, DOTMA) and co-lipids (DOPE, DSPE). Lipoplexes were produced by complexing liposomes with plasmid DNA at different pDNA/CL (w/w) ratios. Our results showed that appropriate pDNA/CL ratios allowing total complexation of plasmid DNA differed depending on the structure of the lipid used. The transfection rates showed that (i) higher rates were obtained with DOTMA lipoplexes, (ii) DC-Chol lipoplexes provided a transfection twice as important as DOTAP lipoplexes and (iii) when DSPE was added, the cytotoxicity decreased while transfection rates were similar. We found that formulations composed of DC-Chol:DOPE:DSPE or DOTMA:DOPE were appropriate to complex plasmid DNA and to transfect human primary dermal fibroblasts with efficacy and limited cytotoxicity. Therefore, these formulations are highly promising in the context of gene therapy to treat skin diseases.

In vitro skin penetration enhancement techniques: A combined approach of ethosomes and microneedles.

Dermal administration of different macromolecules, such as nucleic acids, remains a real challenge because of the difficulty of crossing the main skin barrier, the stratum corneum (SC). To overcome this barrier, the use of deformable lipid-based nanovectors were developed to increase topical penetration through the SC and to promote the intercellular delivery of drugs. The purpose of this study is to compare the skin penetration of different liposome formulations according to their composition. In vitro and ex vivo experiments using Franz diffusion cells were performed to highlight the effect of (i) lipid charge, (ii) edge activators (EA) and (iii) ethanol on the diffusion properties of nanovectors. We showed that all formulations were not able to cross the SC. However, on a tape stripped skin, we showed that cationic formulations containing an EA and ethanol improved the skin penetration. The use of microneedles was considered to bypass the SC. We have shown that sodium cholate and ethanol were necessary to ensure an appropriate diffusion of liposomes into the dermis when applied by means of microneedles. This could be a promising approach to further deliver efficiently macromolecules such as genes into the skin.

Spousal Caregiving Is Associated with an Increased Risk of Frailty: A Case-Control Study.

BACKGROUND: Evidence suggests that providing care for a disabled elderly person may have implications for the caregiver's own health (decreased immunity, hypertension, and depression). OBJECTIVE: Explore if older spousal caregivers are at greater risks of frailty compared to older people without a load of care. DESIGN: Case-control study. SETTING: Participants were assessed at home in Wallonia, Belgium. PARTICIPANTS: Cases: community-dwelling spousal caregivers of older patients, recruited mainly by the geriatric outpatient clinic. CONTROLS: people living at home with an independent spouse at the functional and cognitive level matched for age, gender and comorbidities. MEASUREMENTS: Mini nutritional assessment-short form (MNA-SF), short physical performance battery (SPPB), frailty phenotype (Fried), geriatric depression scale (GDS-15), clock drawing test, sleep quality, and medications. The multivariable analysis used a conditional logistic regression. RESULTS: Among 79 caregivers, 42 were women; mean age and Charlson comorbidity index were 79.4±5.3 and 4.0±1.2, respectively. Among care-receivers (mean age 81.4±5.2), 82% had cognitive impairment. Caregiving was associated with a risk of frailty (Odd Ratio (OR) 6.66; 95% confidence interval (CI) 2.20-20.16), the consumption of antidepressants (OR 4.74; 95% CI 1.32 -17.01), shorter nights of sleep (OR 3.53; 95% CI 1.37-9.13) and more difficulties maintaining a social network (OR 5.25; 95% CI 1.68-16.40). CONCLUSIONS: Spousal caregivers were at an increased risk of being frail, having shorter nights of sleep, taking antidepressants and having difficulties maintaining their social network, compared to non-caregiver controls. Older spousal caregivers deserve the full attention of professionals to prevent functional decline and anticipate a care breakdown.

Identification of potential anti-photoageing algal compounds using an in-vitro model of photoageing.

Stress-induced premature senescence (SIPS) has been proposed as an in-vitro model for testing the long-term effects of stressful events and to find molecules/natural extracts that protect against such stress. Premature senescence of human skin diploid fibroblasts (HDFs) can be induced by repeated subcytotoxic exposure to UVB, with the appearance of so-called biomarkers of senescence such as growth arrest, senescence-associated beta-galactosidase activity, senescence-associated gene over-expression and the common 4977-bp mitochondrial DNA deletion. This model of UVB-induced premature senescence has been acknowledged as a robust in-vitro model in photoageing research. In this study, the potential anti-photoageing effects of a series of algal extracts were tested. The appearance of the biomarkers of UVB-induced premature senescence of HDFs was studied with or without algal extracts. One algal extract was shown to be particularly protective against UVB-induced SIPS. The results obtained here reinforce the notion that UVB-induced premature senescence of HDFs can be used to screen potential anti-photoageing compounds.

Novel ageing-biomarker discovery using data-intensive technologies.

Ageing is accompanied by many visible characteristics. Other biological and physiological markers are also well-described e.g. loss of circulating sex hormones and increased inflammatory cytokines. Biomarkers for healthy ageing studies are presently predicated on existing knowledge of ageing traits. The increasing availability of data-intensive methods enables deep-analysis of biological samples for novel biomarkers. We have adopted two discrete approaches in MARK-AGE Work Package 7 for biomarker discovery; (1) microarray analyses and/or proteomics in cell systems e.g. endothelial progenitor cells or T cell ageing including a stress model; and (2) investigation of cellular material and plasma directly from tightly-defined proband subsets of different ages using proteomic, transcriptomic and miR array. The first approach provided longitudinal insight into endothelial progenitor and T cell ageing. This review describes the strategy and use of hypothesis-free, data-intensive approaches to explore cellular proteins, miR, mRNA and plasma proteins as healthy ageing biomarkers, using ageing models and directly within samples from adults of different ages. It considers the challenges associated with integrating multiple models and pilot studies as rational biomarkers for a large cohort study. From this approach, a number of high-throughput methods were developed to evaluate novel, putative biomarkers of ageing in the MARK-AGE cohort.