Search

Technological advancements in research on circulating biomarkers from patient derived blood have enabled a less invasive means of diagnosing non-hematologic cancers. Considered a more practical way of real-time patient monitoring than traditional tumor biopsy, liquid biopsy markers including circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and extracellular vesicles (EVs) and exosomes certainly have the potential to change the dynamics of cancer management and treatment. Liquid biopsy essentially presents a snapshot of the disease from the primary and/or distant tumor locations and can be utilized for repeated sampling of tumor markers to adjust therapy according to the patient's response to treatment, also known as personalized or precision treatment. In this review, we discuss the research progress in this field with respect to each of the liquid biopsy markers ranging from CTCs, EVs to ctDNA. First, we highlight key CTC technologies that have been commercialized and extensively employed for patient sample analysis. Next, we present some recent developments with regards to exosome and ctDNA research. We then conclude with some future perspectives on the areas of research for these biomarkers. Taken together, we believe these non-invasive capabilities and their potential for diagnostic development can influence treatment selections and aid precision cancer therapies. [ABSTRACT FROM AUTHOR]

The blood–brain barrier (BBB) and the blood–brain tumor barrier (BBTB) prevent drug and nano-drug delivery systems from entering the brain. However, ligand-mediated nano-drug delivery systems have significantly enhanced the therapeutic treatment of glioma. In this study we investigated the mechanism especially the integrity of liposomes and lipid disks while traversing the BBB and BBTB both in vitro and in vivo . Fluorophores (DiO, DiI and DiD) were loaded into liposomes and lipid disks to form Förster resonance energy transfer (FRET) nano-drug delivery systems. Using brain capillary endothelial cells as a BBB model, we show that liposomes and disks are present in the cytoplasm as their intact forms and traverse the BBB with a ratio of 0.68‰ and 1.67‰, respectively. Using human umbilical vein endothelial cells as BBTB model, liposomes and disks remained intact and traversed the BBTB with a ratio of 2.31‰ and 8.32‰ at 3 h. Ex vivo imaging and immunohistochemical results revealed that liposomes and disks could traverse the BBB and BBTB in vivo as intact forms. In conclusion, these observations explain in part the mechanism by which nano-drug delivery systems increase the therapeutic treatment of glioma. [ABSTRACT FROM AUTHOR]

Few molecular details of effectors of Heterodera avenae parasitism are known. We performed a high-throughput sequencing analysis of the H. avenae transcriptome at five developmental stages. A total of 82,549 unigenes were ultimately obtained, and 747 transcripts showed best hits to genes putatively encoding carbohydrate-active enzymes in plant-parasitic nematodes that play an important role in the invasion process. A total of 1,480 unigenes were homologous to known phytonematode effectors, and 63 putative novel effectors were identified in the H. avenae transcriptomes. Twenty-three unigenes were analyzed by qRT-PCR and confirmed to be highly expressed during at least one developmental stage. For in situ hybridization, 17 of the 22 tested putative effectors were specifically expressed and located in the subventral gland cells, and five putative novel effectors were specifically expressed in the dorsal gland. Furthermore, 115 transcripts were found to have putative lethal RNA interference (RNAi) phenotypes. Three target genes with lethal RNAi phenotypes and two of the four tested putative effectors were associated with a decrease in the number of cysts through in vitro RNAi technology. These transcriptomic data lay a foundation for further studies of interactions of H. avenae with cereal and H. avenae parasitic control. [ABSTRACT FROM AUTHOR]

A cyclophosphazene derivative (HACP) was sythesized by hexachlorocyclotriphosphazine and butylamine. Then it was combined with β-CD and used to prepare polylactic acid (PLA) composites. Effect of HACP and β-CD on thermal stability of PLA was studied. The results showed that char residue at final temperature increased with the increasing HACP and β-CD content.These char layers formed on the sample surface can act as an excellent barrier of mass transport and thermal insulation. HACP produced phosphoric and polyphosphoric acids during thermal degradation, which served as the dehydration agents and was the driving force for the formation of the heat resistant carbonaceous char by carbonization. Therefore, HACP and β-CD had a good effect in improving the thermal stability of PLA. [ABSTRACT FROM AUTHOR]

Delivery of biomacromolecules into the eye is greatly hindered by several protective barriers. The cell-penetrating peptide, penetratin, has been found to be an effective absorption enhancer for noninvasive intraocular gene delivery. To discern the composition of penetratin for safe penetration from cornea to retina, we designed a series of penetratin derivatives by varying the hydrophobicity and evaluated their potency for retina-targeted delivery. The hydrophilic amino acids of penetratin, excluding the conserved basic amino acid residues, were respectively replaced with tryptophan. Secondary structure of the resultant derivatives was analyzed by computer simulation and circular dichroism, exhibiting that the hydrophobic derivatives had a propensity to form high content of helix and entered corneal and conjunctival cells more easily than did penetratin. As expected, the hydrophobic derivatives showed improved permeability in excised rabbit cornea and sclera, and kept intact after penetration. When instilled topically in the conjunctival sac of mice eyes, the hydrophobic derivatives distributed safely and rapidly into both cornea and retina, with increased amount and prolonged retention time in comparison to penetratin. In conclusion, we demonstrated that the ocular permeability of penetratin derivatives closely correlated with their hydrophobicity, and introducing hydrophobic amino acids in penetratin was a feasible approach to develop more powerful ocular absorption enhancers. Statement of Significance Due to the defensive barriers of the eye, efficient and safe absorption enhancers are indispensable for noninvasive delivery of exogenous biomacromolecules to the posterior segment. In this manuscript, we designed a series of penetratin derivatives and validated they had significantly improved penetration ability from cornea to retina than wild-type penetratin, without increasing toxicity. More importantly, we provided a sequence of solid evidences that the ocular permeability of penetratin derivatives closely correlated with their hydrophobicity, and introducing hydrophobic amino acids in penetratin was a feasible approach to develop more powerful ocular absorption enhancers. We also demonstrated that the penetratin derivatives permeated through cornea and sclera with intact structure, and might enter the eye by non-corneal pathway. [ABSTRACT FROM AUTHOR]

Protein glycosylation mediates a wide range of cellular processes, affecting development and disease in mammals. Deciphering the “glycocodes” requires rapid, sensitive and in-depth characterization of diverse glycan structures derived from biological samples. In this study, we described a two-step derivatization strategy termed linkage-specific sialic acid permethylation (SSAP) consisting of dimethylamination and permethylation for the improved profiling of glycosylation by matrix-assisted laser desorption/ionization (MALDI) time-of-fight (TOF) mass spectrometry (MS). High linkage-specificity (∼99%) of SSAP to both the two most common forms of sialic acid, N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), permitted direct discrimination of α2,3- and α2,6-linked sialic acids in MALDI-TOF MS. The enhanced intensity (>10-fold) and increased detection limit (>10-fold) of derivatized glycans were valued for sensitive glycomics. Moreover, the good compatibility and reaction efficiency of the two steps of SSAP allowed rapid sample preparation (<2 h), benefiting robust analysis of glycans in a high-throughput manner. The SSAP strategy was further applied to investigate the protein glycosylation of human serum associated with rheumatoid arthritis (RA). It was demonstrated that the relative abundances of individual glycans were different in RA negative and RA positive samples, and meanwhile the RA patient/control ratios of both α2,3- and α2,6-sialylated glycans tended to elevate accompanied with the increase of sialylation. Those findings of the glycosylation changes occurred in human serum protein may contribute to the diagnosis of RA. Herein, SSAP derivatization combined with MALDI-TOF MS exhibits unique advantages for glycomic analysis and shows potential in glycosylation profiling of therapeutic proteins and clinical glycan biomarker discovery. [ABSTRACT FROM AUTHOR]

Our present study aimed to develop an antisense oligonucleotide (ASO) delivery system to achieve gene silencing in intraocular tumor via topical instillation. ASO specific for luciferase was chosen as model drug, polyamidoamine (PG5) was employed to condense ASO, and penetratin (Pene) was used to enhance cellular uptake. Nanoscale PG5/ASO/Pene polyplex was stabilized via noncovalent bonding. In vitro evaluations indicated that PG5/ASO/Pene exhibited improved cell-penetrating and gene silencing ability compared with naked ASO and PG5/ASO. Subcutaneous and orthotopic tumor models expressing luciferase were established in nude mice. After treated by PG5/ASO/Pene, immunohistochemical results of subcutaneous tumors showed significant inhibition of luciferase expression via peritumoral injection, and bioluminescence from orthotopic tumor was obviously weakened via topical instillation. To date, few works were successful in noninvasive treatment of intraocular diseases using antisense strategy, this penetratin-modified polyplex could be a promising vector to inhibit protein expression by effectively delivering ASOs into the eye. [ABSTRACT FROM AUTHOR]

Reductive amination is an indispensable method for glycomic analysis, as it tremendously facilitates glycan characterization and quantification by coupling functional tags at the reducing ends of glycans. However, traditional in-solution derivatization based approach for the preparation of reductively aminated glycans is quite tedious and time-consuming. Here, a simpler and more efficient strategy termed solid-phase reductive amination was investigated. The general concept underlying this new approach is to streamline glycan extraction, derivatization, and purification on non-porous graphitized carbon sorbents. Neutral and sialylated standard glycans were utilized to test the feasibility of the solid-phase method. As results, almost complete labeling of those glycans with four common labels of aniline, 2-aminobenzamide (2-AB), 2-aminobenzoic acid (2-AA) and 2-amino-N-(2-aminoethyl)-benzamide (AEAB) was obtained, and negligible desialylation occurred during sample preparation. The labeled glycans derived from glycoproteins showed excellent reproducibility in high performance liquid chromatography (HPLC) and matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Direct comparisons based on fluorescent absorbance and relative quantification using isotopic labeling demonstrated that the solid-phase strategy enabled 20–30% increase in sample recovery. In short, the solid-phase strategy is simple, reproducible, efficient, and sensitive for glycan analysis. This method was also successfully applied for N-glycan profiling of HEK 293 cells with MALDI-TOF MS, showing its attractive application in the high-throughput analysis of mammalian glycome. [ABSTRACT FROM AUTHOR]

Cereal cyst nematodes (Heterodera avenae and H.filipjevi) and root lesion nematodes (Pratylenchus spp.) have been found to infect cereals in 16 provinces of China. To develop a nematicide that effectively controls nematodes, two novel chemical products, methylene bis thiocyanate (MBT) and MBT + thiamethoxam (MTT); four common pesticides, fipronil + chlorpyrifos (FIC), emamectin benzoate, imidacloprid, and Bacillus thuringiensis; and one fungicide, iprodione, were tested as seed coatings for the control of cereal cysts and root lesion nematodes from 2013 to 2015. Wheat seeds were treated with these seven seed coatings before sowing, and changes in the numbers of Heterodera spp. and Pratylenchus spp. were recorded during three different growth stages. Wheat yields were also compared after harvest. All treatments reduced the numbers of Pratylenchus in wheat and of cysts and eggs of Heterodera in the soil compared with the untreated control. Among the treatments, application of MTT or FIC was more effective than that of the other treatments for nematode control, and the other treatments had similar effects. The results of this study have demonstrated that MTT and FIC applied as seed treatments effectively reduce the number of cysts, inhibit the reproduction of Heterodera and Pratylenchus, and enhance wheat yields. MTT and FIC are thus suitable for controlling nematodes on wheat under natural field conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] The last two decades have witnessed a continuously increasing number of biomacromolecules approved for the treatment of ocular diseases. The eye possesses multiple protective mechanisms to resist the invasion of exogenous substances, but meanwhile these physiological defense systems also act as strong barriers, impeding absorption of most biomacromolecules into the eye. As a result, local injections play predominant roles for posterior ocular delivery of biomacromolecules in clinical practice. To achieve safe and convenient application of biomacromolecules, alternative strategies to realize noninvasive intraocular delivery are necessary. Various nanocarriers, novel penetration enhancers and physical strategies have been explored to facilitate delivery of biomacromolecules to both anterior and posterior ocular segments but still suffered difficulties in clinical translation. This review compares the anatomical and physiological characteristics of the eyes from those frequently adopted experimental species and profiles the well-established animal models of ocular diseases. We also summarize the ophthalmic biomacromolecules launched on the market and put emphasis on emerging noninvasive intraocular delivery strategies of peptides, proteins and genes. [ABSTRACT FROM AUTHOR]