The role of platelets in the regulation of tumor growth and metastasis: the mechanisms and targeted therapy.

Platelets are a class of pluripotent cells that, in addition to hemostasis and maintaining vascular endothelial integrity, are also involved in tumor growth and distant metastasis. The tumor microenvironment is a complex and comprehensive system composed of tumor cells and their surrounding immune and inflammatory cells, tumor-related fibroblasts, nearby interstitial tissues, microvessels, and various cytokines and chemokines. As an important member of the tumor microenvironment, platelets can promote tumor invasion and metastasis through various mechanisms. Understanding the role of platelets in tumor metastasis is important for diagnosing the risk of metastasis and prolonging survival. In this study, we more fully elucidate the underlying mechanisms by which platelets promote tumor growth and metastasis by modulating processes, such as immune escape, angiogenesis, tumor cell homing, and tumor cell exudation, and further summarize the effects of platelet-tumor cell interactions in the tumor microenvironment and possible tumor treatment strategies based on platelet studies. Our summary will more comprehensively and clearly demonstrate the role of platelets in tumor metastasis, so as to help clinical judgment of the potential risk of metastasis in cancer patients, with a view to improving the prognosis of patients.

Versatile design and synthesis of nano-barcodes.

Encoded nano-structures/particles have been used for barcoding and are in great demand for the simultaneous analysis of multiple targets. Due to their nanoscale dimension(s), nano-barcodes have been implemented favourably for bioimaging, in addition to their security and multiplex bioassay application. In designing nano-barcodes for a specific application, encoding techniques, synthesis strategies, and decoding techniques need to be considered. The encoding techniques to generate unique multiple codes for nano-barcodes are based on certain encoding elements including optical (fluorescent and non-fluorescent), graphical, magnetic, and phase change properties of nanoparticles or their different shapes and sizes. These encoding elements can generally be embedded inside, decorated on the surface of nanostructures or self-assembled to prepare the nano-barcodes. The decoding techniques for each encoding technique are different and need to be suitable for the desired applications. This review will provide a thorough discussion on designing nano-barcodes, focusing on the encoding techniques, synthesis methods, and decoding for applications including bio-detection, imaging, and anti-counterfeiting. Additionally, associated challenges in the field and potential solutions will also be discussed. We believe that a comprehensive understanding on this topic could significantly contribute towards the advancement of nano-barcodes for a broad spectrum of applications.

Selection of suitable detergents for obtaining an active dengue protease in its natural form from E. coli.

Dengue protease is a two-component enzyme and is an important drug target against dengue virus. The protease activity and protein stability of dengue nonstructural protein 3 (NS3) require a co-factor region from a four-span membrane protein NS2B. A natural form of dengue protease containing full-length NS2B and NS3 protease domain NS2BFL-NS3pro will be useful for dengue drug discovery. In current study, detergents that can be used for protease purification were tested. Using a water soluble protease construct, 39 detergents were selected for both NS2B and NS2BFL-NS3pro purification. The results showed that 18 detergents were able to sustain the activity of the natural dengue protease and 11 detergents could be used for NS2B purification. The results obtained in this study will be useful for biochemical and biophysical studies on dengue protease.

Upconversion nanoparticle based LRET system for sensitive detection of MRSA DNA sequence.

In this short communication we report an efficient and versatile method for the detection of methicillin-resistant staphylococcus aureus (MRSA) DNA sequence with high sensitivity and specificity. This method is based on upconversion nanoparticles (UCNs) and luminescence resonance energy transfer (LRET) between NaYF4:Yb, Er UCNs, the energy donor, and carboxytetramethylrhodamine (TAMRA), the energy acceptor. The NaYF4:Yb, Er UCNs were prepared with citrate capping thus dispersible in aqueous solutions. MRSA capture oligonucleotides were covalently immobilized onto the surface of the UCNs. TAMRA labeled MRSA DNA report oligonucleotides were brought close to the UCNs upon sandwich hybridization between the capture and report oligonucleotides and a long MRSA target DNA, resulting in an efficient LRET. Specific detection of MRSA DNA sequences with a detection limit as low as 0.18nM was achieved using this method. To the best of our knowledge, this is the first report to detect MRSA DNA sequence by using UCNs as energy donor through an efficient LRET process.

Detection of hemi/homozygotes through heteroduplex formation in high-resolution melting analysis.

Heteroduplex formation, required for the complete detection of hemi/homozygotes using high-resolution melting analysis, can be induced either by pre-PCR mixing of genomic DNAs or by post-PCR mixing of PCR products from unknown and reference samples. This study investigates the effects of both methods using two single nucleotide polymorphisms in X-linked DMD gene. The results show that both methods resulted in the same effect when mixing samples with the same gene copy number. Mixing samples with different gene copy numbers has not been previously explored and we show that post-PCR mixing is insensitive to gene copy number differences as compared to pre-PCR mixing.

Use of the upside-down method to prepare porous polymer films with tunable surface pore sizes.

Porous polyurethane films with well-ordered pores were prepared using polystyrene microspheres as a template, and the surface pore sizes were tuned using a new upside-down (USD) method. After polystyrene microspheres were self-assembled on a substrate and the voids between microspheres were infiltrated with a polyurethane prepolymer solution, the samples were placed upside down to allow the prepolymer solution to flow back before it was solidified. The surface pore sizes of the porous films were tuned by changing the time in which the samples were placed upside down. Using microspheres of the same size, we prepared porous polyurethane films with surface pore sizes ranging from 32 to 87% of the templating microsphere size.