18 research outputs found
Biodegradable Nanocarriers Resembling Extracellular Vesicles Deliver Genetic Material with the Highest Efficiency to Various Cell Types
Efficient delivery of genetic material to primary cells remains challenging. Here, efficient transfer of genetic material is presented using synthetic biodegradable nanocarriers, resembling extracellular vesicles in their biomechanical properties. This is based on two main technological achievements: generation of soft biodegradable polyelectrolyte capsules in nanosize and efficient application of the nanocapsules for co‐transfer of different RNAs to tumor cell lines and primary cells, including hematopoietic progenitor cells and primary T cells. Near to 100% efficiency is reached using only 2.5 × 10−4 pmol of siRNA, and 1 × 10−3 nmol of mRNA per cell, which is several magnitude orders below the amounts reported for any of methods published so far. The data show that biodegradable nanocapsules represent a universal and highly efficient biomimetic platform for the transfer of genetic material with the utmost potential to revolutionize gene transfer technology in vitro and in vivo
The Eurasian Modern Pollen Database (EMPD), version 2
The Eurasian (nee European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).Peer reviewe
The Eurasian Modern Pollen Database (EMPD), version 2
The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019)Swiss National Science Foundation | Ref. 200021_16959
The Eurasian Modern Pollen Database (EMPD), version 2
Abstract. The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).</jats:p
Micropackaging via layer-by-layer assembly: microcapsules and microchamber arrays
The micropackaging of chemical compounds in a small and precisely defined quantity, which can be encased, stored, is essential for response to a specific chemical, biological or physical trigger in a controllable manner is one of the premier challenges in the development of delivery systems. In this review, the authors discuss the application of layer-by-layer (LbL) assemblies of macromolecules for micropackaging and controlled release of various types of cargo. The LbL assembly method provides unique opportunities by incorporation of different functional and responsive layer constituents tailored into one entity. Micron and submicron sized capsules made on colloidal templates are used for biomolecule encapsulation and enable time- and site-specific release when triggered by pH, temperature, specific enzymes, mechanic load, light, ultrasound, or magnetic field. In comparison to individual capsules, the authors discuss the recently introduced micropackaging approach involving cargo loading into arrays of microchambers, made by a combination of imprinting technology and LbL assembly. In conclusion, the authors summarise advantages and fabrication obstacles for micropackaging in capsules and microchambers and discuss already existing as well as potential future applications
Layer-by-Layer Assembled Multilayer Shells for Encapsulation and Release of Fragrance
Layer-by-layer
assembled shells are prospective candidates for encapsulation, stabilization,
storage, and release of fragrances. A shell comprising four alternative
layers of a protein and a polyphenol is employed to encapsulate the
dispersed phase of a fragrance-containing oil-in-water emulsion. The
model fragrance used in this work consists of 10 ingredients, covering
a range of typically employed aroma molecules, all premixed in equal
mass and with sunflower oil acting as the base. The encapsulated emulsion
is stable after 2 months of storage at 4 °C as revealed by static
light scattering and confocal laser scanning microscopy. Gas chromatography/mass
spectrometry data show that the encapsulation efficiency of 8 out
of 10 fragrance ingredients depends on the water solubility: the less
water-soluble an ingredient, the more of it is encapsulated. The amount
of these fragrance ingredients remaining encapsulated decreases linearly
upon emulsion incubation at 40 °C and the multilayer shell does
not hinder their release. The other two fragrance ingredients having
the lowest saturation vapor pressure demonstrate sustained release
over 5 days of incubation at 40 °C. The composition of released
fragrance remains almost constant over 3 days of incubation, upon
further incubation it becomes enriched with these two ingredients
when others start to be depleted
Multilayer Capsules of Bovine Serum Albumin and Tannic Acid for Controlled Release by Enzymatic Degradation
With
the purpose to replace expensive and significantly cytotoxic positively
charged polypeptides in biodegradable capsules formed via Layer-by-Layer
(LbL) assembly, multilayers of bovine serum albumin (BSA) and tannic
acid (TA) are obtained and employed for encapsulation and release
of model drugs with different solubility in water: hydrophilic-tetramethylrhodamine-isothiocyanate-labeled
BSA (TRITC-BSA) and hydrophobic 3,4,9,10-tetra-(hectoxy-carbonyl)-perylene
(THCP). Hydrogen bonding is proposed to be predominant within thus
formed BSA/TA films. The TRITC-BSA-loaded capsules comprising 6 bilayers
of the protein and polyphenol are benchmarked against the shells composed
of dextran sulfate (DS) and poly-l-arginine (PARG) on degradability
by two proteolytic enzymes with different cleavage site specificity
(i.e., α-chymotrypsin and trypsin) and toxicity for murine RAW264.7
macrophage cells. Capsules of both types possess low cytotoxicity
taken at concentrations equal or below 50 capsules per cell, and evident
susceptibility to α-chymotrypsin resulted in release of TRITC-BSA.
While the BSA/TA-based capsules clearly display resistance to treatment
with trypsin, the assemblies of DS/PARG extensively degrade. Successful
encapsulation of THCP in the TRITC-BSA/TA/BSA multilayer is confirmed,
and the release of the model drug is observed in response to treatment
with α-chymotrypsin. The thickness, surface morphology, and
enzyme-catalyzed degradation process of the BSA/TA-based films are
investigated on a planar multilayer comprising 40 bilayers of the
protein and polyphenol deposited on a silicon wafer. The developed
BSA/TA-based capsules with a protease-specific degradation mechanism
are proposed to find applications in personal care, pharmacology,
and the development of drug delivery systems including those intravenous
injectable and having site-specific release capability
In Vitro Bioeffects of Polyelectrolyte Multilayer Microcapsules Post-Loaded with Water-Soluble Cationic Photosensitizer
Microencapsulation and targeted delivery of cytotoxic and antibacterial agents of photodynamic therapy (PDT) improve the treatment outcomes for infectious diseases and cancer. In many cases, the loss of activity, poor encapsulation efficiency, and inadequate drug dosing hamper the success of this strategy. Therefore, the development of novel and reliable microencapsulated drug formulations granting high efficacy is of paramount importance. Here we report the in vitro delivery of a water-soluble cationic PDT drug, zinc phthalocyanine choline derivative (Cholosens), by biodegradable microcapsules assembled from dextran sulfate (DS) and poly-l-arginine (PArg). A photosensitizer was loaded in pre-formed [DS/PArg]4 hollow microcapsules with or without exposure to heat. Loading efficacy and drug release were quantitatively studied depending on the capsule concentration to emphasize the interactions between the DS/PArg multilayer network and Cholosens. The loading data were used to determine the dosage for heated and intact capsules to measure their PDT activity in vitro. The capsules were tested using human cervical adenocarcinoma (HeLa) and normal human dermal fibroblast (NHDF) cell lines, and two bacterial strains, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Our results provide compelling evidence that encapsulated forms of Cholosens are efficient as PDT drugs for both eukaryotic cells and bacteria at specified capsule-to-cell ratios
Biodegradable nanocarriers resembling extracellular vesicles deliver genetic material with the highest efficiency to various cell types
Abstract
Efficient delivery of genetic material to primary cells remains challenging. Here, efficient transfer of genetic material is presented using synthetic biodegradable nanocarriers, resembling extracellular vesicles in their biomechanical properties. This is based on two main technological achievements: generation of soft biodegradable polyelectrolyte capsules in nanosize and efficient application of the nanocapsules for co‐transfer of different RNAs to tumor cell lines and primary cells, including hematopoietic progenitor cells and primary T cells. Near to 100% efficiency is reached using only 2.5 × 10–4 pmol of siRNA, and 1 × 10–3 nmol of mRNA per cell, which is several magnitude orders below the amounts reported for any of methods published so far. The data show that biodegradable nanocapsules represent a universal and highly efficient biomimetic platform for the transfer of genetic material with the utmost potential to revolutionize gene transfer technology in vitro and in vivo