Elucidation of Spatial Cooperativity in Chemo-Immunotherapy by a Sequential Dual-pH-Responsive Drug Delivery System.

Combining immune checkpoint blockade with chemotherapy through nanotechnology is promising in terms of safety and efficacy. However, the distinct subcellular distribution of each ingredient's action site makes it challenging to acquire an optimal synergism. Herein, a dual-pH responsive hybrid polymeric micelle system, HNP(αPDL16.9, Dox5.3), is constructed as a proof-of-concept for the spatial cooperativity in chemo-immunotherapy. HNP retains the inherent pH-transition of each polymer, with stepwise disassembly under discrete pH thresholds. Within weakly acidic extracellular tumor environment, αPDL1 is first released to block the checkpoint on cell membranes. The remaining intact Doxorubicin-loaded micelle NP(Dox)5.3 displays significant tropism toward tumor cells and releases Dox upon lysosomal pH for efficient tumor immunogenic cell death without immune toxicity. This sequential-released pattern boosts DC activation and primes CD8+ T cells, leading to enhanced therapeutic performance than single agent or an inverse-ordered combination in multiple murine tumor models. Using HNP, the indispensable role of conventional type 1 DC (cDC1) is identified in chemo-immunotherapy. A co-signature of cDC1 and CD8 correlates with cancer patient survival after neoadjuvant Pembrolizumab plus chemotherapy in clinic. This study highlights spatial cooperativity of chemo- and immuno-agents in immunoregulation and provides insights into the rational design of drug combination for future nanotherapeutics development.

An efficient cocrystallization strategy for separation of dihydromyricetin from vine tea and enhanced its antibacterial activity for food preserving application.

The objective of this study was to optimize the separation and purification of dihydromyricetin (DMY) from vine tea to obtain high purity, antibacterial and antioxidant crystal forms. We developed a cocrystallization approach for separation of DMY from vine tea with easy operation and high efficiency. The type and concentration of co-formers as well as solvent for separation have been investigated in detail. Under the optimal conditions, DMY with a purity of 92.41% and its two co-crystal forms (purity >97%) can be obtained. Three DMY crystal forms had consistent and good antioxidant activities according to DPPH radical scavenging results. DMY had effective antibacterial activity against the two kinds of drug-resistant bacteria including CRAB and MRSA, and DMY co-crystals had a greater advantage than DMY itself on CRAB. This work implies that cocrystallization can be used for the DMY separation and enhanced its anti-drug-resistant bacteria activity in food preservation.

Thermal property evaluation of a 2.5D integration method with device level microchannel direct cooling for a high-power GaN HEMT device.

Gallium nitride high electron mobility transistor (GaN HEMT) devices have become critical components in the manufacturing of high-performance radio frequency (RF) or power electronic modules due to their superior characteristics, such as high electron saturation speeds and high power densities. However, the high heat characteristics of GaN HEMTs make device level cooling a critical problem to solve since performance degradation or even failure may occur under high temperatures. In this paper, we proposed a 2.5D integration method with device-level microchannel direct cooling for a high-power GaN HEMT device. To demonstrate this technological concept, a multigate GaN HEMT device featuring a gate length/width/source drain spacing of 0.5 µm/300 µm/6 µm that underwent in-house backside thinning and metallization was used as the test vehicle. A high-resistivity silicon (HR Si) interposer embedded with four-layer microchannels was designed, having widths/pitches of 30 µm/30 µm at the top microchannel. The high-power GaN HEMT device was soldered on a Si interposer embedded with open microchannels for heat dissipation. A pair of GSG Pad chips was soldered simultaneously to display the capacity for the heterogeneous integration of other chip types. Thermal property evaluation was conducted with experiments and simulations. The test results showed that the maximum surface temperature of the GaN HEMT device decreased to 93.8 °C when it experienced a heat dissipation density of 32 kW/cm2 in the gate finger area and an average heat dissipation density of 5 kW/cm2 was found in the active area with the DI water coolant at a flow rate of 3 mL/min. To our knowledge, among recently reported works, this finding was the best cooling capacity of heterogeneously integrated microchannels for GaN HEMT devices. In addition, this technology was scalable regarding the numbers of gate fingers or GaN HEMT devices.

A Glass-Ultra-Thin PDMS Film-Glass Microfluidic Device for Digital PCR Application Based on Flexible Mold Peel-Off Process.

The microfluidic device (MFD) with a glass−PDMS−glass (G-P-G) structure is of interest for a wide range of applications. However, G-P-G MFD fabrication with an ultra-thin PDMS film (especially thickness less than 200 µm) is still a big challenge because the ultra-thin PDMS film is easily deformed, curled, and damaged during demolding and transferring. This study aimed to report a thickness-controllable and low-cost fabrication process of the G-P-G MFD with an ultra-thin PDMS film based on a flexible mold peel-off process. A patterned photoresist layer was deposited on a polyethylene terephthalate (PET) film to fabricate a flexible mold that could be demolded softly to achieve a rigid structure of the glass−PDMS film. The thickness of ultra-thin patterned PDMS could reach less than 50 µm without damage to the PDMS film. The MFD showcased the excellent property of water evaporation inhibition (water loss < 10%) during PCR thermal cycling because of the ultra-thin PDMS film. Its low-cost fabrication process and excellent water evaporation inhibition present extremely high prospects for digital PCR application.

Multi-compartment supracapsules made from nano-containers towards programmable release.

The assembly of nanomaterials into suprastructures offers the possibility to fabricate larger scale functional materials, whose inner structure strongly influences their functionality for a vast range of applications. In spite of the many current strategies, achieving multi-compartment structures in a targeted and versatile way remains highly challenging. Here, we describe a controllable and straightforward route to create uniform suprastructured materials with a multi-compartmentalized architecture by confining primary nanocapsules into droplets using a cross-junction microfluidic device. Following solvent evaporation from the droplets, the nanocapsules spontaneously assemble into precisely sized multi-compartment particles, which we term supracapsules. Thanks to the process, each spatially separated nanocapsule unit retains its cargo and functionalities within the resulting supracapsules. However, new collective properties emerge, and, particularly, programmable release profiles that are distinct from those of single-compartment capsules. Finally, the suprastructures can be disassembled into single-compartment units by applying ultra-sonication, switching their release to a burst-release mode. These findings open up exciting opportunities to fabricate multi-compartment suprastructures incorporating diverse functionalities for materials with emerging properties.

Puerarin-Na Chelate Hydrate Simultaneously Improves Dissolution and Mechanical Behavior.

Puerarin monohydrate (PUEM), as the commercial solid form of the natural anti-hypertension drug puerarin (PUE), has low solubility, poor flowability, and mechanical properties. In this study, a novel solid form as PUE-Na chelate hydrate was prepared by a reactive crystallization method. Crystal structure analysis demonstrated that PUE-Na contains PUE-, Na+, and water in a molar ratio of 1:1:7. It crystallizes in the monoclinic space group P21, and Na+ is linked with PUE- and four water molecules through Na+ ← O coordination bonds. Another three crystal water molecules occupy channels along the crystallographic b-axis. Observing along the b-axis, the crystal structure features a distinct tubular helix and a DNA-like twisted helix. The complexation between Na+ and PUE- in aqueous solution was confirmed by the Na+ selective electrode, indicating that PUE-Na chelate hydrate belongs to a type of chelate rather than organic metal salt. Compared with PUEM, PUE-Na exhibited a superior dissolution rate (i.e., ∼38-fold increase in water) owing to its lower solvation free energy and clear-enriched exposed polar groups. Moreover, PUE-Na enhanced the tabletability and flowability of PUEM, attributing to its better elastoplastic deformation and lower-friction crystal habit. The unique PUE-Na chelate hydrate with significantly enhanced pharmaceutical properties is a very promising candidate for future product development of PUE.

Competitive cocrystallization and its application in the separation of flavonoids.

Recently, cocrystallization has been widely employed to tailor physicochemical properties of drugs in the pharmaceutical field. In this study, cocrystallization was applied to separate natural compounds with similar structures. Three flavonoids [baicalein (BAI), quercetin (QUE) and myricetin (MYR)] were used as model compounds. The coformer caffeine (CAF) could form cocrystals with all three flavonoids, namely BAI-CAF (cocrystal 1), QUE-CAF (cocrystal 2) and MYR-CAF (cocrystal 3). After adding CAF to methanol solution containing MYR and QUE (or QUE and BAI), cocrystal 3 (or cocrystal 2) preferentially formed rather than cocrystal 2 (or cocrystal 1), indicating that flavonoid separation could be achieved by competitive cocrystallization. After co-mixing the slurry of two flavonoids with CAF followed by centrifugation, the resolution ratio that could be achieved was 70-80% with purity >90%. Among the three cocrystals, cocrystal 3 showed the lowest formation constant with a negative Gibbs free energy of nucleation and the highest energy gap. Hirshfeld surface analysis and density of states analysis found that cocrystal 3 had the highest strong interaction contribution and the closest electronic density, respectively, followed by cocrystal 2 and cocrystal 1, suggesting CAF could competitively form a cocrystal with MYR much more easily than QUE and BAI. Cocrystallization is a promising approach for green and effective separation of natural products with similar chemical structures.

A novel drug-drug coamorphous system without molecular interactions: improve the physicochemical properties of tadalafil and repaglinide.

Tadalafil and repaglinide, categorized as BCS class II drugs, have low oral bioavailabilities due to their poorly aqueous solubilities and dissolutions. The aim of this study was to enhance the dissolution of tadalafil and repaglinide by co-amorphization technology and evaluate the storage and compression stability of such coamorphous system. Based on Flory-Huggins interaction parameter (χ ≤ 0) and Hansen solubility parameter (δ t ≤ 7 MPa0.5) calculations, tadalafil and repaglinide was predicted to be well miscible with each other. Coamorphous tadalafil-repaglinide (molar ratio, 1 : 1) was prepared by solvent-evaporation method and characterized with respect to its thermal properties, possible molecular interactions. A single T g (73.1 °C) observed in DSC and disappearance of crystallinity in PXRD indicated the formation of coamorphous system. Principal component analysis of FTIR in combination with Raman spectroscopy and Ss 13C NMR suggested the absence of intermolecular interactions in coamorphous tadalafil-repaglinide. In comparison to pure crystalline forms and their physical mixtures, both drugs in coamorphous system exhibited significant increases in intrinsic dissolution rate (1.5-3-fold) and could maintain supersaturated level for at least 4 hours in non-sink dissolution. In addition, the coamorphous tadalafil-repaglinide showed improved stability compared to the pure amorphous forms under long-term stability and accelerated storage conditions as well as under high compressing pressure. In conclusion, this study showed that co-amorphization technique is a promising approach for improving the dissolution rate of poorly water-soluble drugs and for stabilizing amorphous drugs.

Transport mechanism of ursodeoxycholic acid in human placental BeWo cells.

Ursodeoxycholic acid (UDCA) is a first-line drug to treat intrahepatic cholestasis of pregnancy (ICP). However, its effects on the fetus are not clearly known. To better guide its clinical use, we aimed to study the mechanism underlying the placental transport of UDCA. The uptake and efflux of UDCA across placental apical membranes were studied using BeWo cells; effects of different exposure durations, UDCA concentrations, temperatures, and inhibitors of transporters were studied. A transwell assay was performed, and UDCA concentration in both fetal and maternal sides was measured using LC-MS/MS. Higher unidirectional transport of UDCA was observed in the basolateral-to-apical direction than in the apical-to-basolateral direction. Ko143 and verapamil, which are typical inhibitors of efflux transporters, significantly increased UDCA transport from different directions. UDCA uptake from the apical membrane of BeWo cells was time-dependent, but sodium-independent. It was inhibited by inhibitors of energy metabolism and of organic anion transporters, indicating an active transport mechanism. UDCA uptake from the apical membranes of BeWo cells could be mediated by organic anion-transporting polypeptides, whereas its efflux could be mediated by breast cancer resistance protein and multidrug resistant protein 3. The results of the present study may provide a basis for UDCA use in pregnancy.

ZC3H12D attenuated inflammation responses by reducing mRNA stability of proinflammatory genes.

Infection in airspaces and lung parenchyma may cause acute lung injury and multiple organ dysfunction syndrome due to acute inflammatory response, leading to organ failure and high mortality. ZC3H12D has been shown to modulate Toll-like receptor signaling. This study aimed to investigate the change of ZC3H12D during acute lung injury and its role in inflammation processes. Mice were challenged with lipopolysaccharides (LPS) intratracheally. The expression levels of Zc3h12d, NF-κB, and cytokines were analyzed by quantitative real-time PCR (qPCR), ELISA, and Western blot. The mRNA stability was assessed by qPCR after cells were treated with actinomycin D for specified times. The 3' untranslated region (3'-UTR) of c-fos was cloned immediately downstream of the luciferase coding sequence driven by CMV promoter and luciferase activity was measured with a Luciferase Assay kit. Upon LPS treatment, ZC3H12D levels were reduced in mouse immune cells, whereas levels of NF-κB, IL-6, and TNF-α were significantly increased. Knockdown Zc3h12d in THP1 cells resulted in the upregulation of NF-κB while overexpression of Zc3h12d inhibited NF-κB expression. Ectopic Zc3h12d significantly reduced the mRNA stability of c-fos, NF-κB, TNF-α, IL-1ß, and IL-6. Attachment of the c-fos 3'-UTR made luciferase expression levels sensitive to levels of ZC3H12D. The data indicated that ZC3H12D could suppress both the initial inflammation storm and chronic inflammation by targeting the mRNA of cytokines as well as NF-κB and c-fos.