Despite the long history of investigations of polyelectrolyte multilayer formation on solid or liquid surfaces, important questions remain open concerning the construction of the first set of layers. These are generally deposited on a first anchoring layer of different chemistry, influencing their construction and properties. We propose here an in-depth investigation of the formation of NaPSS/PAH multilayers at the air/water interface in the absence of a chemically different anchoring layer, profiting from the surface activity of NaPSS.
View Article and Find Full Text PDFOil/water interfaces are ubiquitous in nature. Opposing polarities at these interfaces attract surface-active molecules, which can seed complex viscoelastic or even solid interfacial structure. Biorelevant proteins such as hydrophobin, polymers such as PNIPAM, and the asphaltenes in crude oil (CRO) are examples of some systems where such layers can occur.
View Article and Find Full Text PDFTraction patterns of adherent cells provide important information on their interaction with the environment, cell migration, or tissue patterns and morphogenesis. Traction force microscopy is a method aimed at revealing these traction patterns for adherent cells on engineered substrates with known constitutive elastic properties from deformation information obtained from substrate images. Conventionally, the substrate deformation information is processed by numerical algorithms of varying complexity to give the corresponding traction field via solution of an ill-posed inverse elastic problem.
View Article and Find Full Text PDFAn increasing number of multi-phase systems exploit complex interfaces in which capillary stresses are coupled with solid-like elastic stresses. Despite growing efforts, simple and reliable experimental characterisation of these interfaces remains a challenge, especially of their dilational properties. Pendant drop techniques are convenient, but suffer from complex shape changes and associated fitting procedures with multiple parameters.
View Article and Find Full Text PDFChemotactic migration of bacteria-their ability to direct multicellular motion along chemical gradients-is central to processes in agriculture, the environment, and medicine. However, current understanding of migration is based on studies performed in bulk liquid, despite the fact that many bacteria inhabit tight porous media such as soils, sediments, and biological gels. Here, we directly visualize the chemotactic migration of Escherichia coli populations in well-defined 3D porous media in the absence of any other imposed external forcing (e.
View Article and Find Full Text PDFElastin-like polypeptides (ELPs) undergo a characteristic phase transition in response to ambient temperature. Therefore, it has been be used as a thermosensitive vector for the delivery of chemotherapy agents since it can be used to target hyperthermic tumors. This novel strategy introduces unprecedented options for treating cancer with fewer concerns about side effects.
View Article and Find Full Text PDFModern pendant drop tensiometry relies on the numerical solution of the Young-Laplace equation and allows us to determine the surface tension from a single picture of a pendant drop with high precision. Most of these techniques solve the Young-Laplace equation many times over to find the material parameters that provide a fit to a supplied image of a real droplet. Here, we introduce a machine learning approach to solve this problem in a computationally more efficient way.
View Article and Find Full Text PDFPurpose: The purpose of this study was to investigate the albumin-binding compound In-C4-DTPA as an imaging agent for the detection of endogenous albumin accumulation in tumors.
Methods: In-C4-DTPA was injected in healthy nude mice for pharmacokinetic and biodistribution studies (10 min, 1, 6, 24, and 48 h, = 4) and subsequently in tumor-bearing mice for single-photon emission computed tomography/X-ray-computed tomography (SPECT/CT) imaging studies. Four different human tumor xenograft models (LXFL529, OVXF899, MAXFTN401, and CXF2081) were implanted subcutaneously unilaterally or bilaterally ( = 4-8).
Auristatins are a class of highly cytotoxic tubulin-disrupting peptides, which have shown limited therapeutic effect as free agents in clinical trials. In our continuing effort to develop acid-sensitive albumin-binding anticancer drugs exploiting circulating serum albumin as the drug carrier, we investigated the highly toxic drug payload auristatin E to assess whether the corresponding albumin-binding prodrugs were a viable option for achieving significant and concomitant tolerable antitumor activity. To achieve our goal, we developed a new aromatic maleimide-bearing linker (Sulf07) which enhanced both water solubility and stability of the prodrugs.
View Article and Find Full Text PDFThe generation of rationally designed polymer therapeutics via the conjugation of low molecular weight anti-cancer drugs to water-soluble polymeric nanocarriers aims to improve the therapeutic index. Here, we focus on applying polymer therapeutics to target two cell compartments simultaneously - tumour cells and angiogenic endothelial cells. Comparing different polymeric backbones carrying the same therapeutic agent and targeting moiety may shed light on any correlation between the choice of polymer and the anti-cancer activity of the conjugate.
View Article and Find Full Text PDFBackground: Worldwide, consistent survival benefit for chemotherapy in hepatocellular carcinoma (HCC) is a golden goal for concerned researchers. Nexavar (sorafenib) is the only approved agent that achieved touchable successes in this regard. Thus, there is a pressing medical need for new promising drugs to improve HCC therapy.
View Article and Find Full Text PDFBiochem Eng J
August 2014
Nanomaterials that are used in therapeutic applications need a high degree of uniformity and functionality which can be difficult to attain. One strategy for fabrication is to utilize the biological precision afforded by recombinant synthesis. Through protein engineering, we have produced ~27-nm dodecahedral protein nanoparticles using the thermostable E2 subunit of pyruvate dehydrogenase as a scaffold and added optical imaging, drug delivery, and tumor targeting capabilities.
View Article and Find Full Text PDFJ Control Release
April 2014
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.
View Article and Find Full Text PDFJ Biomed Nanotechnol
January 2014
The development of effective polymer-based nanocarriers which are able to target diseased tissues still remains a great challenge in current research. Dendritic polyglycerols have emerged as novel polymeric scaffolds that have demonstrated a great potential for diverse biomedical applications. These architectures have already proven their usefulness in therapeutic approaches related to multivalency, given by the synergy between the nanosized dimensions combined with the high density of functional groups.
View Article and Find Full Text PDFJ Control Release
September 2014
Human serum albumin (HSA) has emerged as a versatile carrier for therapeutic agents, primarily for treating diabetes and cancer, improving the pharmacokinetic profile of the drug or delivering the drug to the pathogenic site addressing diseases with unmet medical needs. Market approved products include fatty acid derivatives of human insulin or the glucagon-like-1 peptide (Levemir, Tresiba, and Victoza) which bind physically to the respective binding sites of HSA thus extending their half-life. For cancer treatment, the paclitaxel albumin nanoparticle Abraxane has been approved for treating metastatic breast cancer, non-small cell lung cancer, and advanced pancreatic cancer.
View Article and Find Full Text PDFA novel pH and redox dual-responsive prodrug nanogel was prepared by an inverse nanoprecipitation method, which is mild and surfactant free, and based on a thiol-disulfide exchange reaction and thiol-Michael addition reaction. Highly biocompatible hyperbranched polyglycerol (hPG) was cross-linked with disulfide bonds, to obtain biodegradable nanogels, which could be degraded under intracellular reductive conditions. Doxorubicin (DOX) was conjugated to the biodegradable nanogel matrix via an acid-labile hydrazone linker.
View Article and Find Full Text PDFDevelopment of effective polymer-based nanocarriers for the successful application in cancer therapy still remains a great challenge in current research. In the present study we present a dendritic polyglycerol-based multifunctional drug immunoconjugate that specifically targets and kills cancer cell lines expressing epidermal growth factor receptor (EGFR). The nanocarrier was provided with a dendritic core as a multifunctional anchoring point, doxorubicin (Doxo) coupled through a pH-sensitive linker, a fluorescence marker, poly(ethylene glycol), as solubilizing and shielding moiety, and a scFv antibody conjugated through the SNAP-Tag technology.
View Article and Find Full Text PDFActivation of mast cells (MCs) can be achieved by the high-affinity receptor for IgE (FcεRI) as well as by additional receptors such as the lipopolysaccharide (LPS) receptor and the receptor tyrosine kinase Kit (stem cell factor [SCF] receptor). Thus, pharmacological interventions which stabilize MCs in response to different receptors would be preferable in diseases with pathological systemic MC activation such as systemic mastocytosis. 1,4-Benzodiazepines (BDZs) have been reported to suppress MC effector functions.
View Article and Find Full Text PDFIn this work, we evaluated combinations of doxorubicin with INNO-206, a (6-maleimidocaproyl)hydrazone derivative of doxorubicin (DOXO-EMCH) that is currently undergoing two phase II clinical trials, in a primarily chemoresistant tumor indication, i.e. pancreatic cancer.
View Article and Find Full Text PDFBone metastases are a frequent cause of morbidity in cancer patients. The present palliative therapeutic options are chemotherapy, hormone therapy, and the administration of bisphosphonates. The affinity between bisphosphonates and the apatite structure of bone metastases is strong.
View Article and Find Full Text PDFElastin-like polypeptide (ELP) is a macromolecular carrier with thermally responsive properties that can passively accumulate in solid tumors and additionally aggregate in tumor tissue when exposed to hyperthermia. In this study, ELP was conjugated to the anticancer drug doxorubicin (DOXO) and three different cell penetrating peptides (CPP) in order to inhibit tumor growth in mice compared to free doxorubicin. Fluorescence microscopy studies in MCF-7 breast carcinoma cells demonstrated that the three different CPP-ELP-DOXO conjugates delivered doxorubicin to the cell nucleus.
View Article and Find Full Text PDFAnticancer drugs as well as nano-sized drug delivery systems face many barriers that hinder penetration deeply and evenly into solid tumors: a chaotic, tortuous vascular compartment resulting in tumor tissue distant from microvessels, a heterogeneous blood flow distribution with a concomitant defective microcirculatory exchange process, and a high interstitial fluid pressure. Furthermore, a resulting hostile tumor microenvironment characterized by hypoxia and/or extracellular acidosis can reduce the efficacy of anticancer drugs and confer drug resistance. Conversely, the enhanced permeation and retention effect has become the gold standard for developing macromolecular prodrugs and nano-sized drug delivery systems.
View Article and Find Full Text PDFElastin-like polypeptides (ELP) aggregate in response to mild hyperthermia, but remain soluble under normal physiologic conditions. ELP macromolecules can accumulate in solid tumors because of the enhanced permeability and retention effect. Tumor retention of ELPs can be further enhanced through hyperthermia-induced aggregation of ELPs by local heating of the tumor.
View Article and Find Full Text PDFPancreatic cancer progresses aggressively and owing to chemoresistance responds poorly to chemotherapy. Thus, there is an urgent need to understand the mechanisms of cancer cell resistance to generate effective strategies to circumvent intrinsic chemoresistance in this tumour indication. In this study, three pancreatic cancer cell lines, MIA PaCa-2, MDAPanc-3 and AsPC-1, were treated with the proteasome inhibitor MG-132 together with camptothecin, doxorubicin or paclitaxel, and cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.
View Article and Find Full Text PDFThe P-glycoprotein (P-gp) is a 170-kDa protein that acts as an energy dependent, transmembrane efflux pump and is encoded by the MDR1 gene. It has been shown to be responsible for multidrug resistance (MDR) in a defined subpopulation of breast cancer patients and thus represents a molecular target for circumventing MDR in this tumor indication. MDR modulators have been developed and demonstrated high selectivity for P-gp with inhibitory activities in the low nanomolar range.
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