Biodegradable Nanocomposite Antimicrobials for the Eradication of Multidrug-Resistant Bacterial Biofilms without Accumulated Resistance.

Infections caused by multidrug-resistant (MDR) bacteria are a rapidly growing threat to human health, in many cases exacerbated by their presence in biofilms. We report here a biocompatible oil-in-water cross-linked polymeric nanocomposite that degrades in the presence of physiologically relevant biomolecules. These degradable nanocomposites demonstrated broad-spectrum penetration and elimination of MDR bacteria, eliminating biofilms with no toxicity to cocultured mammalian fibroblast cells. Notably, serial passaging revealed that bacteria were unable to develop resistance toward these nanocomposites, highlighting the therapeutic promise of this platform.

Anti-YKL-40 antibody and ionizing irradiation synergistically inhibit tumor vascularization and malignancy in glioblastoma.

Chemo/radiotherapies are the most common adjuvant modality treated for patients with glioblastoma (GBM) following surgery. However, the overall therapeutic benefits are still uncertain, as the mortality remains high. Elevated expression of YKL-40 in GBM was correlated with increases in mural cell-associated vessel coverage, stability and density, and decreases in vessel permeability and disease survival. To explore the potential role of YKL-40 in mural cell-mediated tumor vascularization, we employed an anti-YKL-40 neutralizing antibody (mAY) and ionizing irradiation (IR) in xenografted brain tumor models. Although single treatment with mAY or IR partially increased mouse survival, their combination led to dramatic inhibition in tumor growth and increases in mouse survival. mAY blocked mural cell-mediated vascular stability, integrity and angiogenesis; whereas IR merely promoted tumor cell and vascular cell apoptosis. Vascular radioresistance is at least partially attributed to expression of YKL-40 in mural cells. These divergent effects were also recapitulated in cultured systems using endothelial cells and mural cells differentiated from glioblastoma stem-like cells (GSCs). Dysfunction of intercellular contact N-cadherin was found to mediate mAY-inhibited vascularization. Collectively, the data suggest that the conjunction therapy with mAY and IR synergistically inhibit tumor vascularization and progression. The evidence may shed light on a new adjuvant therapy in clinic.

DNA aptamer-functionalized PDA nanoparticles: from colloidal chemistry to biosensor applications.

Polydopamine nanoparticles (PDA NPs) are widely utilized in the field of biomedical science for surface functionalization because of their unique characteristics, such as simple and low-cost preparation methods, good adhesive properties, and ability to incorporate amine and oxygen-rich chemical groups. However, challenges in the application of PDA NPs as surface coatings on electrode surfaces and in conjugation with biomolecules for electrochemical sensors still exist. In this work, we aimed to develop an electrochemical interface based on PDA NPs conjugated with a DNA aptamer for the detection of glycated albumin (GA) and to study DNA aptamers on the surfaces of PDA NPs to understand the aptamer-PDA surface interactions using molecular dynamics (MD) simulation. PDA NPs were synthesized by the oxidation of dopamine in Tris buffer at pH 10.5, conjugated with DNA aptamers specific to GA at different concentrations (0.05, 0.5, and 5 µM), and deposited on screen-printed carbon electrodes (SPCEs). The charge transfer resistance of the PDA NP-coated SPCEs decreased, indicating that the PDA NP composite is a conductive bioorganic material. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed that the PDA NPs were spherical, and dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy data indicated the successful conjugation of the aptamers on the PDA NPs. The as-prepared electrochemical interface was employed for the detection of GA. The detection limit was 0.17 µg/mL. For MD simulation, anti-GA aptamer through the 5'terminal end in a single-stranded DNA-aptamer structure and NH2 linker showed a stable structure with its axis perpendicular to the PDA surface. These findings provide insights into improved biosensor design and have demonstrated the potential for employing electrochemical PDA NP interfaces in point-of-care applications.

Anticancer and anti-angiogenic activities of mannooligosaccharides extracted from coconut meal on colorectal carcinoma cells in vitro.

Colorectal carcinoma (CRC) is one of the most common malignancies, though there are no effective therapeutic regimens at present. This study aimed to investigate the inhibitory effects of mannooligosaccharides extracted from coconut meal (CMOSs) on the proliferation and migration of human colorectal cancer HCT116 cells in vitro. The results showed that CMOSs exhibited significant inhibitory activity against HCT116 cell proliferation in a concentration-dependent manner with less cytotoxic effects on the Vero normal cells. CMOSs displayed the ability to increase the activation of caspase-8, -9, and -3/7, as well as the generation of reactive oxygen species (ROS). Moreover, CMOSs suppressed HCT116 cell migration in vitro. Interestingly, treatment of human microvascular endothelial cells (HMVECs) with CMOSs resulted in the inhibition of cell proliferation, cell migration, and capillary-like tube formation, suggesting its anti-vascular angiogenesis. In summary, the results of this study indicate that CMOSs could be a valuable therapeutic candidate for CRC treatment.

Biogenic synthesis of gold nanoparticles mediated by Spondias dulcis (Anacardiaceae) peel extract and its cytotoxic activity in human breast cancer cell.

Green synthesis is a new paradigm for the preparation of gold nanoparticles (AuNPs) due to its cost-effectiveness and favorable environmental impact. This study presented a simple phytosynthesis process for the preparation of AuNPs utilizing the aqueous peel extract of Spondias dulcis (SPE) (Anacardiaceae) as both a reducing and stabilizing agent. A visual color change from yellow to purple during the reaction implied the successful formation of SPE-AuNPs, which was confirmed by UV-vis spectroscopy. Transmission electron microscopy (TEM) images indicated that the SPE-AuNPs were predominantly spherical with a mean size of 36.75 ± 11.36 nm, and were comprised of crystalline Au, as indicated by X-ray diffraction. In terms of their potential application, SPE-AuNPs exhibit significant cytotoxic activity in a dose- and time-dependent manner to MCF-7 human breast cancer cells, while being non-toxic to Vero normal cells. The treatment of MCF-7 cells with SPE-AuNPs increased the production of intracellular reactive oxygen species (ROS). Herein, the findings highlight the potential contribution of phytosynthesized SPE-AuNPs to the development of novel nanomedicines for cancer treatment.

Green synthesized apigenin conjugated gold nanoparticles inhibit cholangiocarcinoma cell activity and endothelial cell angiogenesis in vitro.

Cholangiocarcinoma (CCA) is a rare malignancy of the biliary tract with extremely poor clinical outcomes due to a lack of effective therapies to improve disease management. The emerging green synthesis of gold nanoparticles (AuNPs) has extensively provided their use in biomedical applications. In this study, we developed AuNPs via reducing gold salts with apigenin (4',5,7-trihydroxyflavone). The synthesized apigenin-conjugated AuNPs (api-AuNPs) were physicochemically characterized by various techniques before evaluation their biological and functional inhibition in a CCA cell line, KKU-M055. The mean size of api-AuNPs was 90.34 ± 22.82 nm with zeta potential of -36 ± 0.55. The half-maximal inhibitory concentration (IC50, 0.8 mg/mL) of api-AuNPs on cell proliferation of KKU-M055 was 1.9-fold less than that of an immortalized human cholangiocyte cell line, MMNK1 (IC50, 1.5 mg/mL). Moreover, api-AuNPs induced cell apoptosis via the up-regulation of Bax, Bid, and Caspase 3, and down-regulation of Bcl2, leading to elevated caspase 3/7, 8, 9 activities and reactive oxygen species (ROS) production. The api-AuNPs significantly inhibited the migration of KKU-M055 cells and suppressed the proliferation, migration, and in vitro tube formation of vascular endothelial cells. Collectively, our findings indicate the dual abilities of api-AuNPs that potentially inhibit cancer cell growth and motility as well as endothelial cell-mediated angiogenesis, which may offer a novel therapeutic avenue to treat CCA patients effectively.

Cloning and expression analysis of the Bombyx mori α-amylase gene (Amy) from the indigenous Thai silkworm strain, Nanglai.

α-Amylase is a common enzyme for hydrolyzing starch. In the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), α-amylase is found in both digestive fluid and hemolymph. Here, the complete genomic sequence of the Amy gene encoding α-amylase from a local Thai silkworm, the Nanglai strain, was obtained. This gene was 7981 bp long with 9 exons. The full length Amy cDNA sequence was 1749 bp containing a 1503 bp open reading frame. The ORF encoded 500 amino acid residues. The deduced protein showed 81-54% identity to other insect α-amylases and more than 50% identity to mammalian enzymes. Southern blot analysis revealed that in the Nanglai strain Amy is a single-copy gene. RT- PCR showed that Amy was transcribed only in the foregut. Transgenic B. mori also showed that the Amy promoter activates expression of the transgene only in the foregut.

Chitinase 3 like 1 (CHI3L1) promotes vasculogenic mimicry formation in cervical cancer.

Vasculogenic mimicry (VM) is an alternative microvascular system which tumour cells orchestrate, independent of endothelial cell-mediated angiogenesis. VM develops tumour vascular networks that correlate with tumour growth, metastasis, and short survival time of patients with a number of cancers. However, little is known regarding VM in the vascularisation of cervical cancer. Chitinase 3 like 1 (CHI3L1) has been previously reported to display the ability to induce angiogenesis in cervical cancer. Here, we explored a pathological role of CHI3L1 in tumour cell-mediated vascularisation. Sixty-six samples of cervical cancer were collected to examine CHI3L1 expression and VM formation using immunohistochemistry and CD34-periodic acid-Schiff (PAS) dual staining. CHI3L1 expression was significantly correlated with formation of tumour cell-associated vascular channels in the absence of endothelial cells (p=0.031). Interestingly, tumour samples lacking VM were positively correlated with non-metastasis (p=0.035). Patients with VM positive tumours tended to have decreased overall survival (OS) compared to those with VM negative samples (43.9 versus 64.6 months, p=0.079). In addition, recombinant CHI3L1 enhanced cervical cancer cell lines to form tube-like structures, supporting the notion that CHI3L1 mediates VM in cervical cancer. Our present data reveal the crucial role of CHI3L1 in the formation of VM, which may contribute to tumour aggressiveness. Therefore, targeting CHI3L1 may be a valuable strategy for the reduction of cervical cancer vascularisation and metastasis.

A Heparin Binding Motif Rich in Arginine and Lysine is the Functional Domain of YKL-40.

The heparin-binding glycoprotein YKL-40 (CHI3L1) is intimately associated with microvascularization in multiple human diseases including cancer and inflammation. However, the heparin-binding domain(s) pertinent to the angiogenic activity have yet been identified. YKL-40 harbors a consensus heparin-binding motif that consists of positively charged arginine (R) and lysine (K) (RRDK; residues 144-147); but they don't bind to heparin. Intriguingly, we identified a separate KR-rich domain (residues 334-345) that does display strong heparin binding affinity. A short synthetic peptide spanning this KR-rich domain successfully competed with YKL-40 and blocked its ability to bind heparin. Three individual point mutations, where alanine (A) substituted for K or R (K337A, K342A, R344A), led to remarkable decreases in heparin-binding ability and angiogenic activity. In addition, a neutralizing anti-YKL-40 antibody that targets these residues and prevents heparin binding impeded angiogenesis in vitro. MDA-MB-231 breast cancer cells engineered to express ectopic K337A, K342A or R344A mutants displayed reduced tumor development and compromised tumor vessel formation in mice relative to control cells expressing wild-type YKL-40. These data reveal that the KR-rich heparin-binding motif is the functional heparin-binding domain of YKL-40. Our findings shed light on novel molecular mechanisms underlying endothelial cell angiogenesis promoted by YKL-40 in a variety of diseases.

Targeted delivery of 5-fluorouracil to cholangiocarcinoma cells using folic acid as a targeting agent.

There are limits to the standard treatment for cholangiocarcinoma (CCA) including drug resistance and side effects. The objective of this study was to develop a new technique for carrying drugs by conjugation with gold nanoparticles and using folic acid as a targeting agent in order to increase drug sensitivity. Gold nanoparticles (AuNPs) were functionalized with 5-fluorouracil (5FU) and folic acid (FA) using polyethylene glycol (PEG) shell as a linker (AuNPs-PEG-5FU-FA). Its cytotoxicity was tested in CCA cell lines (M139 and M213) which express folic acid receptor (FA receptor). The results showed that AuNPs-PEG-5FU-FA increased the cytotoxic effects in the M139 and M213 cells by 4.76% and 7.95%, respectively compared to those treated with free 5FU+FA. It is found that the cytotoxicity of the AuNPs-PEG-5FU-FA correlates with FA receptor expression suggested the use of FA as a targeted therapy. The mechanism of cytotoxicity was mediated via mitochondrial apoptotic pathway as determined by apoptosis array. In conclusion, our findings shed some light on the use of gold nanoparticles for conjugation with potential compounds and FA as targeted therapy which contribute to the improvement of anti-cancer drug efficacy. In vivo study should be warranted for its effectiveness of stability, biosafety and side effect reduction.

Chitinase 3 like 1 is associated with tumor angiogenesis in cervical cancer.

Elevated serum levels of a secreted glycoprotein chitinase 3 like 1 (CHI3L1) are associated with poor prognosis and short survival time of patients with cervical cancer (CxCa). Our previous microarray data showed the increased expression of CHI3L1 in invasive CxCa compared to normal tissue, implicating a potential role of CHI3L1 in CxCa. To establish the pathological role of CHI3L1 in the development of CxCa, this study focused on its expression in CxCa and angiogenic impacts in tumor vessel formation. CHI3L1 activated angiogenesis by promoting endothelial cell migration and tube formation in vitro but failed to protect CxCa cell lines, CaSki and HeLa against apoptosis induced by γ-irradiation. In addition, the capability of CHI3L1 to induce proliferation and migration of CaSki and HeLa cells was cell type specific. In an analysis of 103 specimens from CxCa patients, increased expression levels of CHI3L1 mRNA and protein in invasive CxCa were 4-fold (P<0.05) and 2-fold (P<0.01), respectively, stronger than those in normal subjects. The immunostaining of CHI3L1 was positively correlated with VEGF expression (P=0.0019) and microvessel density (P=0.0110). Moreover, CHI3L1 expression was also positively associated with cancer metastasis (P=0.011). The data suggest the crucial role of CHI3L1 by promoting angiogenesis, which may contribute to the development and progression of CxCa. The findings help establish CHI3L1 as a prognostic biomarker and therapeutic target for CxCa patients.