Hyaluronic Acid-Coated Camptothecin Nanocrystals for Targeted Drug Delivery to Enhance Anticancer Efficacy

Tumor-targeted drug delivery via chemotherapy is very effective on cancer treatment. For potential anticancer agent such as Camptothecin (CPT), high chemotherapeutic efficacy and accurate tumor targeting are equally crucial. Inspired by special CD44 binding capability from hyaluronic acid (HA), in this study, novel HA-coated CPT nanocrystals were successfully prepared by an antisolvent precipitation method for tumor-targeted delivery of hydrophobic drug CPT. These HA-coated CPT nanocrystals demonstrated high drug loading efficiency, improved aqueous dispersion, prolonged circulation, and enhanced stability resulting from their nanoscaled sizes and hydrophilic HA layer. Moreover, as compared to crude CPT and naked CPT nanocrystals, HA-coated CPT nanocrystals displayed dramatically enhanced in vitro anticancer activity, apoptosis-inducing potency against CD44 overexpressed cancer cells, and lower toxic effect toward normal cells due to pH-responsive drug release behavior and specific HA-CD44 mediated endocytosis. Additionally, HA-coated CPT nanocrystals performed fairly better antimigration activity and biocompatibility. The possible molecular mechanism regarding this novel drug formulation might be linked to intrinsic mitochondria-mediated apoptosis by an increase of Bax to Bcl-2 ratio and upregulation of P53. Consequently, HA-coated CPT nanocrystals are expected to be an effective nanoplatform in drug delivery for cancer therapy.

Assessment for Less than 20-ppm Oil Leakage in Soil Using Terahertz Wave

Although an accurate detection of trace oil leaks is of the utmost important for soil protection, the typically used techniques fail to provide rapid assessment of less than 20 parts per million (ppm) of oil in soil. Terahertz (THz) time-domain spectroscopy, an optical method with high sensitivity to polar organics, was used to characterize the content of crude oil in soils. A linear model was built between the concentration of crude oil and the THz attenuation coefficient, which predicted the limit of detection ranging from 4.11 to 16.2 ppm. Some organics, such as aromatic and aliphatic compounds, contribute to larger absorption in the THz range than minerals. Effective-medium theory was optimized to elucidate the crude oil content dependence of THz dielectric constants. Consequently, THz technology could be an effective method for detecting trace oil leakage in soil.

Lytic peptide-grafted beta-cyclodextrin polymer based nano-scaled drug delivery system with enhanced camptothecin anti-cancer efficacy

The aqueous solubility of drug molecules is closely related to its bioactivity like bioavailability and subsequent therapeutic index, especially in the case of hydrophobic drugs like camptothecin (CPT), a potential broad-spectrum anti-cancer agent. Enhanced anti-cancer activity and selectivity of CPT are equally important. Inspired by host-guest effect and drug combination regimen, we developed a novel tumor lytic peptide incorporated drug delivery system by forming beta-cyclodextrin polymer (BCDp) based inclusion complex in nano-scaled size. In this study, BCDp formed inclusion complex with CPT and then a lytic-type peptide (ZH) was grafted. The resulting combinational formulation of BCDp, CPT and ZH, named as ZH-BCDp-CPT inclusion complex, demonstrated greater solubility resulting from its nano-scaled size, amorphous solid state and inclusion structure. Moreover, ZH facilitated quick internalization of conjugated drug via cell membrane lysis, leading to efficient intracellular drug delivery. This novel drug formulation was featured with prolonged circulation, enhanced anti-cancer efficacy, selectivity, anti-cell migration activity and better biocompatibility in comparison with crude CPT and binary BCDp-CPT inclusion complex, all of which were attributed to a cooperative action between ZH and BCDp-CPT inclusion complex. Our results suggested ZH-BCDp-CPT inclusion complex induced cell apoptosis by up-regulation of Bax and P53 and down-regulation of Bcl-2, primarily involved in the mitochondrial pathways.

High Water Content Prediction of Oil-Water Emulsions Based on Terahertz Electromagnetically Induced Transparency-like Metamaterial

This work aims to investigate the electromagnetically induced transparency-like (EIT-like) metamaterial for high water cut emulsions' detection in the terahertz band. The electromagnetic responses of the selected metamaterial covering emulsions exhibit red-shifted resonant frequency with increasing water volume from 60 to 98%. Three numerical models coinciding with theory analysis were built based on the extracted resonant frequencies at the transmission peak and dips to predict water concentration. The results show that the built models accurately predicted the water content with absolute errors less than 0.26, 0.41, and 0.24%, respectively. The EIT-like resonance is introduced by coupled bright and dark modes, making it similar to a weakened plasma resonance. Consequently, the permittivity-dependent frequency would help develop both economically feasible and socially beneficial sensors for high water content prediction.

Determining the Humidity-Dependent Ortho-to- Para Ratio of Water Vapor at Room Temperature Using Terahertz Spectroscopy

The origin of the water spin isomers observed under various physico-chemical conditions is of great interest, including that of H₂O molecules in the gas phase. Here, terahertz time-domain spectroscopy (THz-TDS) was used to study the humidity-dependent ortho-to- para (O/P) ratio of water vapor at room temperature. The relative contents of para and ortho molecules were obtained by fitting the absorption lines of water vapor showing the relationship between the spin isomer contents and humidity. Larger O/P ratios with values of ∼3.2 were observed at lower humidity (<20%) due to the stronger attractive forces of para molecules. The concentration of the ortho isomers then began to decrease at higher humidity (>20%) due to the preferential formation of dimers and clusters at increasing concentrations. Thus, the ratio gradually decreased with increasing humidity.

Oblique-incidence reflectivity difference application for morphology detection

Analogous with scanning electron microscopy, we use an oblique-incidence reflectivity difference (OIRD) approach for morphology detection. By scanning the active carbon clusters in a one-dimensional way and the reservoir rocks in a two-dimensional way, the morphology of the samples' surface can be revealed in OIRD signal images. High OIRD signals of active carbon samples refer to the centralized distribution areas of carbon, and the fluctuations are caused by the uneven distribution of carbon pellets. OIRD intensity is proportional to the thickness of materials. In terms of rocks, the trough areas with smaller values refer to the low-lying fields. The areas with relatively large OIRD intensities correspond to the protuberance areas of rocks. Consequently, OIRD is a sensitive yet rapid measure of surface detection in material and petrogeology science.

The JAK2V617F-bearing vascular niche promotes clonal expansion in myeloproliferative neoplasms

The acquired kinase mutation JAK2V617F plays a central role in myeloproliferative neoplasms (MPNs). However, the mechanisms responsible for the malignant hematopoietic stem/progenitor cell (HSPC) expansion seen in patients with MPNs are not fully understood, limiting the effectiveness of current treatment. Endothelial cells (ECs) are an essential component of the hematopoietic niche, and they have been shown to express the JAK2V617F mutation in patients with MPNs. We show that the JAK2V617F-bearing vascular niche promotes the expansion of the JAK2V617F HSPCs in preference to JAK2WT HSPCs, potentially contributing to poor donor cell engraftment and disease relapse following stem cell transplantation. The expression of Chemokine (C-X-C motif) ligand 12 (CXCL12) and stem cell factor (SCF) were upregulated in JAK2V617F-bearing ECs compared to wild-type ECs, potentially accounting for this observation. We further identify that the thrombopoietin (TPO)/MPL signaling pathway is critical for the altered vascular niche function. A better understanding of how the vascular niche contributes to HSPC expansion and MPN development is essential for the design of more effective therapeutic strategies for patients with MPNs.

Discriminating the Mineralogical Composition in Drill Cuttings Based on Absorption Spectra in the Terahertz Range

Understanding the geological units of a reservoir is essential to the development and management of the resource. In this paper, drill cuttings from several depths from an oilfield were studied using terahertz time domain spectroscopy (THz-TDS). Cluster analysis (CA) and principal component analysis (PCA) were employed to classify and analyze the cuttings. The cuttings were clearly classified based on CA and PCA methods, and the results were in agreement with the lithology. Moreover, calcite and dolomite have stronger absorption of a THz pulse than any other minerals, based on an analysis of the PC1 scores. Quantitative analyses of minor minerals were also realized by building a series of linear and non-linear models between contents and PC2 scores. The results prove THz technology to be a promising means for determining reservoir lithology as well as other properties, which will be a significant supplementary method in oil fields.

A new targeted delivery approach by functionalizing drug nanocrystals through polydopamine coating

Tumor target specificity via chemotherapy is widely considered to be very effective on tumor treatment. For an ideal chemotherapeutic agent like Camptothecin (CPT) (CPT is the abbreviation for Camptothecin), improved therapeutic efficacy and high selectivity are equally important. Inspired by adhesive proteins in mussels, here we developed a novel tumor targeting peptide XQ1 grafted CPT nanocrystals with polydopamine coating as a spacer. In this study, CPT nanocrystals were coated by polymerization of dopamine that was induced by plasma-activated water under an acidic environment, and then the tumor targeting peptide was grafted onto polydopamine (PDA) (PDA is the abbreviation for polydopamine) coated CPT nanocrystals through catechol chemistry. The PDA layer had negligible effects on drug crystallinity and structure but resulted in drug nanocrystals with excellent dispersion properties, improved dissolution rate and drug stability by preventing water hydrolysis. More importantly, tumor targeting peptide XQ1 facilitated a rapid cross-membrane translocation of drug nanocrystals via receptor-mediated endocytosis, leading to efficient intracellular drug delivery. Moreover, this novel drug formulation demonstrated more potent anti-cancer activity against tumor cells in comparison with free CPT and naked CPT nanocrystals and exhibited high selectivity, all of which are attributed to the tumor target specificity property and inherent pH-dependent drug release behavior.

Anti-cancer activity of camptothecin nanocrystals decorated by silver nanoparticles

CPT/Ag nanocrystals display extreme and broad-spectrum anti-cancer activity and high selectivity through a cooperation effect between CPT and AgNPs.

Extreme Activity of Drug Nanocrystals Coated with A Layer of Non-Covalent Polymers from Self-Assembled Boric Acid

Non-covalent polymers have remarkable advantages over synthetic polymers for wide biomedical applications. In this study, non-covalent polymers from self-assembled boric acid were used as the capping reagent to replace synthetic polymers in drug crystallization. Under acidic pH, boric acid self-assembled on the surface of drug nanocrystals to form polymers with network-like structures held together by hydrogen bonds. Coating driven by boric acid self-assembly had negligible effects on drug crystallinity and structure but resulted in drug nanocrystals with excellent dispersion properties that aided in the formation of a more stable suspension. Boric acid coating improved drug stability dramatically by preventing drug molecules from undergoing water hydrolysis in a neutral environment. More importantly, the specific reactivity of orthoboric groups to diols in cell glycocalyx facilitated a rapid cross-membrane translocation of drug nanocrystals, leading to efficient intracellular drug delivery, especially on cancer cells with highly expressed sialic acids. Boric acid coated nanocrystals of camptothecin, an anticancer drug with poor aqueous solubility and stability, demonstrated extreme cytotoxic activity (IC₅₀ < 5.0 μg/mL) to cancer cells compared to synthetic polymer coated CPT nanocrystals and free CPT. Surface coating using non-covalent polymers from self-assembled boric acid will have wide biomedical applications especially in biomaterials and drug delivery field.

Clostridium difficile-associated clinical burden from lack of diagnostic testing in a Chinese tertiary hospital

Despite Clostridium difficile infection (CDI) being a common cause of diarrhoea in hospitals worldwide, diagnostic testing or management guidelines are not available in most hospitals in China. In this prospective two-year study, the incidence of CDI among 276 patients with watery diarrhoea was 23.1%. Lack of diagnostic testing for CDI was associated with improper management in 26.4% of patients, risk of nosocomial transmission from lack of isolation precautions, and risk of community transmission from discharging symptomatic toxigenic C. difficile carriers. Updating practice guidelines in line with the current evidence and implementing diagnostic testing for CDI are recommended in hospitals in China.