Single-Tailed Lipidoids Enhance the Transfection Activity of Their Double-Tailed Counterparts

Cationic lipid-like molecules (lipidoids) are widely used for in vitro and in vivo gene delivery. Nearly all lipidoids developed to date employ double-tail or multiple-tail structures for transfection. Single-tail lipidoids are seldom considered for transfection as they have low efficiency in gene delivery. So far, there is no detailed study on the contribution to transfection efficiency of single-tail lipidoids when combined with standard double-tail lipidoids. Here, we use combinatorial chemistry to synthesize 17 double-tail and 17 single-tail lipidoids using thiol–yne and thiol–ene click chemistry, respectively. HEK 293T cells were used to analyze transfection efficiency by fluorescence microscopy and calculated based on the percentage of cells transfected. The size and zeta potential of liposomes and lipoplexes were characterized by dynamic light scattering (DLS). Intracellular DNA delivery and trafficking was further examined using confocal microscopy. Our study shows that combining single with double-tail lipidoids increases uptake of lipoplexes, as well as cellular transfection efficiency

Data_Sheet_1_Differential impact of body mass index and leptin on baseline and longitudinal positron emission tomography measurements of the cerebral metabolic rate for glucose in amnestic mild cognitive impairment.pdf

IntroductionSeveral studies have suggested that greater adiposity in older adults is associated with a lower risk of Alzheimer’s disease (AD) related cognitive decline, some investigators have postulated that this association may be due to the protective effects of the adipose tissue-derived hormone leptin. In this study we sought to demonstrate that higher body mass indices (BMIs) are associated with greater baseline FDG PET measurements of the regional cerebral metabolic rate for glucose (rCMRgl), a marker of local neuronal activity, slower rCMRgl declines in research participants with amnestic mild cognitive impairment (aMCI). We then sought to clarify the extent to which those relationships are attributable to cerebrospinal fluid (CSF) or plasma leptin concentrations.Materials and methodsWe used baseline PET images from 716 73 ± 8 years-old aMCI participants from the AD Neuroimaging Initiative (ADNI) of whom 453 had follow up images (≥6 months; mean follow up time 3.3 years). For the leptin analyses, we used baseline CSF samples from 81 of the participants and plasma samples from 212 of the participants.ResultsAs predicted, higher baseline BMI was associated with greater baseline CMRgl measurements and slower declines within brain regions preferentially affected by AD. In contrast and independently of BMI, CSF, and plasma leptin concentrations were mainly related to less baseline CMRgl within mesocorticolimbic brain regions implicated in energy homeostasis.DiscussionWhile higher BMIs are associated with greater baseline CMRgl and slower declines in persons with aMCI, these associations appear not to be primarily attributable to leptin concentrations.</p

Qualitative cerebral blood flow during hypoglycemia and euglycemia in PET and PASL-MRI.

<p>Axial images showing the mean difference (CBF hypoglycemia – CBF euglycemia) maps from nine subjects for A) positron emission tomography (PET) and B) pulse arterial spin labeling magnetic resonance imaging (PASL-MRI). Yellow/orange represents increased and blue represents decreased blood flow during the hypoglycemic relative to euglycemic session. Similar increases in CBF for hypoglycemia were seen for both methods within the thalamus.</p

Flow chart of the restoration process.

<p>Flow chart of the dual-resolution semi rigid and free-form restoration process.</p

Mean (±SE) plasma glucose and counterregulatory hormones at baseline and at time of CBF acquisition for euglycemic and hypoglycemic clamp phases and peak levels during each phase.

<p>Mean (±SE) plasma glucose and counterregulatory hormones at baseline and at time of CBF acquisition for euglycemic and hypoglycemic clamp phases and peak levels during each phase.</p

Patient-specific 3D LV mesh model restoration results.

<p> Two samples of patient-specific 3D LV mesh model before and after dual and free form geometric deformation.</p

Schematic diagram of experimental protocol.

<p>Counterregulatory hormone levels, hypoglycemic symptom scores and rCBF measurements were obtained during the hyperinsulinemic euglycemic – hypoglycemic clamp. rCBF measurements were obtained using PASL-MRI and [¹⁵O]water PET for healthy individuals (<i>n</i> = 9).</p

Table_4_A comparative study on photosynthetic characteristics and flavonoid metabolism between Camellia petelotii (Merr.) Sealy and Camellia impressinervis Chang &Liang.xls

Camellia petelotii (Merr.) Sealy and Camellia impressinervis Chang & Liang belong to the golden subgroup of Camellia (Theaceae). This subgroup contains the yellow-flowering species of the genus, which have high medicinal and ornamental value and a narrow geographical distribution. These species differ in their tolerance to high light intensity. This study aimed to explore the differences in their light-stress responses and light damage repair processes, and the effect of these networks on secondary metabolite synthesis. Two-year-old plants of both species grown at 300 µmol·m-2·s-1 photosynthetically active radiation (PAR) were shifted to 700 µmol·m-2·s-1 PAR for 5 days shifting back to 300 µmol·m-2·s-1 PAR for recovery for 5 days. Leaf samples were collected at the start of the experiment and 2 days after each shift. Data analysis included measuring photosynthetic indicators, differential transcriptome expression, and quantifying plant hormones, pigments, and flavonoids. Camellia impressinervis showed a weak ability to recover from photodamage that occurred at 700 µmol·m-2·s-1 compared with C. petelotii. Photodamage led to decreased photosynthesis, as shown by repressed transcript abundance for photosystem II genes psbA, B, C, O, and Q, photosystem I genes psaB, D, E, H, and N, electron transfer genes petE and F, and ATP synthesis genes ATPF1A and ATPF1B. High-light stress caused more severe damage to C. impressinervis, which showed a stronger response to reactive oxygen species than C. petelotii. In addition, high-light stress promoted the growth and development of high zeatin signalling and increased transcript abundance of adenylate dimethylallyl transferase (IPT) and histidine-containing phosphotransferase (AHP). The identification of transcriptional differences in the regulatory networks that respond to high-light stress and activate recovery of light damage in these two rare species adds to the resources available to conserve them and improve their value through molecular breeding. </p

MOESM2 of Genomics insights into different cellobiose hydrolysis activities in two Trichoderma hamatum strains

Additional file 2. Genome difference genes annotated with NCBI NR, GO, KEGG, KOG, and Pfam

Three-dimensional left ventricle mesh models.

<p>(a) with motion artifacts, and (b) desired result after shape restoration.</p