Nanoparticles are extremely small particles that can be modified for a variety of uses in the medical field. For example, nanoparticles can be engineered to be able to transport medicines specifically to the disease site while not interfering with healthy body parts.
Selective drug transport verified in human tissue for the first time
The Munich scientists have developed nanocarriers that only release the carried drugs in lung tumour areas. The team headed by Silke Meiners, Oliver Eickelberg and Sabine van Rijt from the Comprehensive Pneumology Center (HMGU), working with colleagues from the Chemistry Department (LMU) headed by Thomas Bein, were able to show nanoparticles' selective drug release to human lung tumour tissue for the first time.
Tumour specific proteins were used to release drugs from the nanocarriers
Tumour tissue in the lung contains high concentrations of certain proteases, which are enzymes that break down and cut specific proteins. The scientists took advantage of this by modifying the nanocarriers with a protective layer that only these proteases can break down, a process that then releases the drug. Protease concentrations in the healthy lung tissue are too low to cleave this protective layer and so the medicines stay protected in the nanocarrier.
"Using these nanocarriers we can very selectively release a drug such as a chemotherapeutic agent specifically at the lung tumour," reports research group leader Meiners. "We observed that the drug's effectiveness in the tumour tissue was 10 to 25 times greater compared to when the drugs were used on their own. At the same time, this approach also makes it possible to decrease the total dose of medicines and consequently to reduce undesirable effects."
Further studies will now be directed to examine the safety of the nanocarriers in vivo and verify the clinical efficacy in an advanced lung tumour mouse model.
Therapeutic oligonucleotide analogs represent a new and promising family of drugs that act on nucleic acid targets such as RNA or DNA; however, their effectiveness has been limited due to difficulty crossing the cell membrane. A new delivery approach based on cell-penetrating peptide nanoparticles can efficiently transport charge-neutral oligonucleotide analogs into cells, as reported in Nucleic Acid Therapeutics, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free on the Nucleic Acid Therapeutics website.
In the article, "Peptide Nanoparticle Delivery of Charge-Neutral Splice-Switching Morpholino Oligonucleotides," Peter Järver and coauthors, Cambridge Biomedical Campus (U.K.), Karolinska University Hospital (Huddinge, Sweden), Stockholm University (Sweden), Alexandria University (Egypt), and University of Oxford (U.K.), note that while delivery systems exist to facilitate cell entry of negatively charged oligonucleotide drugs, these approaches are not effective for charge-neutral oligonucleotide analogs. The authors describe lipid-functionalized peptides that form a complex with charge-neutral morpholino oligonucleotides, enabling them to cross into cells and retain their biological activity.
“The exploitation of phosphorodiamidate morpholinos represents an exciting approach to treating a number of therapeutic targets,” says Executive Editor Graham C. Parker, PhD, The Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, MI. “This paper suggests an intriguing but practical approach to solving the lack of a convenient non-covalent delivery system.”
治疗性寡核苷酸类似物代表了一种新的有前途的核酸（RNA or DNA）靶向性药物种类。然而，由于很难穿过细胞膜，药物的效用受到限制。一种基于细胞穿透肽纳米颗粒的新的释放方法可以有效地运输的电中性的寡核苷酸类似物进入细胞。
Uptake efficiency of surface modified gold nanoparticles does not correlate with functional changes and cytokine secretion in human dendritic cells in vitro
Engineering nanoparticles (NPs) for immune modulation require a thorough understanding of their interaction(s) with cells. Gold NPs (AuNPs) were coated with polyethylene glycol (PEG), polyvinyl alcohol (PVA) or a mixture of both with either positive or negative surface charge to investigate uptake and cell response in monocyte-derived dendritic cells (MDDCs). Inductively coupled plasma optical emission spectrometry and transmission electron microscopy were used to confirm the presence of Au inside MDDCs. Cell viability, (pro-)inflammatory responses, MDDC phenotype, activation markers, antigen uptake and processing were analyzed. Cell death was only observed for PVA-NH2 AuNPs at the highest concentration. MDDCs internalize AuNPs, however, surface modification influenced uptake. Though limited uptake was observed for PEG-COOH AuNPs, a significant tumor necrosis factor-alpha release was induced. In contrast, (PEG?+?PVA)-NH2 and PVA-NH2 AuNPs were internalized to a higher extent and caused interleukin-1beta secretion. None of the AuNPs caused changes in MDDC phenotype, activation or immunological properties.
Titanium dioxide (TiO2) nanotubes have potential applications in the biomedical field. This is due to their promising properties such as biocompatibility and high corrosion resistance. These innovative morphologies can be finely tuned at the nanoscale using the selective electrochemical anodization method, providing a high surface area and surface roughness. Reported in Nanotechnology, selected morphologies that have a variety of potential biomedical applications are reviewed.
Natural-Based Nanocomposites for Bone Tissue Engineering and Regenerative Medicine: A Review
Tissue engineering and regenerative medicine has been providing exciting technologies for the development of functional substitutes aimed to repair and regenerate damaged tissues and organs. Inspired by the hierarchical nature of bone, nanostructured biomaterials are gaining a singular attention for tissue engineering, owing their ability to promote cell adhesion and proliferation, and hence new bone growth, compared with conventional microsized materials. Of particular interest are nanocomposites involving biopolymeric matrices and bioactive nanosized fillers. Biodegradability, high mechanical strength, and osteointegration and formation of ligamentous tissue are properties required for such materials. Biopolymers are advantageous due to their similarities with extracellular matrices, specific degradation rates, and good biological performance. By its turn, calcium phosphates possess favorable osteoconductivity, resorbability, and biocompatibility. Herein, an overview on the available natural polymer/calcium phosphate nanocomposite materials, their design, and properties is presented. Scaffolds, hydrogels, and fibers as biomimetic strategies for tissue engineering, and processing methodologies are described. The specific biological properties of the nanocomposites, as well as their interaction with cells, including the use of bioactive molecules, are highlighted. Nanocomposites in vivo studies using animal models are also reviewed and discussed.
A new $10 million gift from Ronald and JoAnne Willens to Northwestern University’s International Institute for Nanotechnology (IIN) will establish an interdisciplinary research center that will use advances in nanotechnology to develop new cancer treatments. It will be one of the first centers of its kind in the country.
Ronald and JoAnne Willens向美国西北大学国际纳米技术研究中心捐出100万美金，将用于建立一个跨领域的研究中心致力于充分利用纳米技术研发出癌症的新疗法。这研究中心将会成为国内首创。