磁性核壳胶囊局域中和胃酸用于活性益生菌的高效递送

近年来基于益生菌的幽门螺旋杆菌感染治疗策略受到了越来越多的关注,然而益生菌在胃部中直接递送会受到胃酸环境的干扰,难以存活,无法有效抑制幽门螺旋杆菌。为了实现益生菌在胃部的高效递送,我们制备了具有核壳结构的益生菌胶囊。胶囊外壳由海藻酸钙(Alg)、碳酸钙(CaCO_(3))以及铁钴磁性石墨纳米囊FeCo@G组成,胶囊内核为益生菌(约氏乳杆菌,Laj)菌液。其中,CaCO_(3)用于局域中和胃酸以保护内核益生菌,而FeCo@G则赋予了胶囊良好的磁驱动性能。我们利用扫描电子显微镜以及细胞显微成像系统等手段考察了益生菌胶囊的形貌和包裹稳定性,结果显示,胶囊能稳定包裹益生菌并抵御模拟胃液(SGF)中盐酸的侵蚀,维持了益生菌活性,并对幽门螺旋杆菌(H.p)具有明显抑制作用。此外,我们进一步探究了Alg/CaCO_(3)/FeCo@G-Laj(ACFL)胶囊在模拟胃部环境内的磁导航运动性能,结果表明,在磁场条件下,ACFL胶囊在不同粘度的介质中均可以实现高效的磁驱动效应,证实了ACFL胶囊的益生菌靶向递送能力。综上,ACFL胶囊为幽门螺旋杆菌的治疗提供新的方法,同时也为胃酸不稳定药物的高效保护以及精准投递提供了新平台。

Complete-basis-reprogrammable coding metasurface for generating dynamicallycontrolled holograms under arbitrary polarization states

Reprogrammable metasurfaces,which establish a fascinating bridge between physical and information domains,can dynamically control electromagnetic(EM)waves in real time and thus have attracted great attentions from researchers around the world.To control EM waves with an arbitrary polarization state,it is desirable that a complete set of basis states be controlled independently since incident EM waves with an arbitrary polarization state can be decomposed as a linear sum of these basis states.In this work,we present the concept of complete-basis-reprogrammable coding metasurface(CBR-CM)in reflective manners,which can achieve independently dynamic controls over the reflection phases while maintaining the same amplitude for left-handed circularly polarized(LCP)waves and right-handed circularly polarized(RCP)waves.Since LCP and RCP waves together constitute a complete basis set of planar EM waves,dynamicallycontrolled holograms can be generated under arbitrarily polarized wave incidence.The dynamically reconfigurable metaparticle is implemented to demonstrate the CBR-CM’s robust capability of controlling the longitudinal and transverse positions of holograms under LCP and RCP waves independently.It’s expected that the proposed CBR-CM opens up ways of realizing more sophisticated and advanced devices with multiple independent information channels,which may provide technical assistance for digital EM environment reproduction.

Versatile Graphene-Isolated AuAg-Nanocrystal for Multiphase Analysis and Multimodal Cellular Raman Imaging

Surface-enhanced Raman spectroscopy(SERS)-based bioanalytical technique involves the interaction of SERS-active substrate with complex environment,which has aroused intensive research interests.Compared to the commonly used Au SERS substrates,Ag nanocrystals have larger optical absorption cross section and acceptable price,but they possess poor oxidation resistance and potential biotoxicity,and the occurrence of unnecessary chemical reactions is inevitable due to the direct contact with probe molecules.Herein,we report a graphene-isolated AuAg nanocrystal(GIAAN)with the SERS-active AuAg core confined in a nanospace of few-layer graphene shell,which possesses unique Raman peaks,high SERS activity,excellent stability,superior fluorescence quenching performance and good biocompatibility.Based on the limited solubility of GIAAN in water and organic solvents,it is able to spontaneously generate interfacial self-assembled GIAAN(ISA-GIAAN)film at immiscible two-phase interfaces without any inducer,and multiphase Raman analysis of both water-and lipid-soluble drug model molecules is further achieved.Moreover,the GIAAN is further non-covalently functionalized with polyoxyethylenestearyl ether(C18-PEG)to acquire GIAAN@PEG with good water-solubility for SERS quantitative analysis in homogeneous system and multimodal Raman imaging of MCF-7 cells.We expect the versatile GIAAN holds great potential to monitor drug metabolism and guide intended drug delivery in clinic trials.

Natural interface-mediated self-assembly of graphene-isolatednanocrystals for plasmonic arrays construction and personalized information acquisition

As Interface mediated self-assembly of nanocrystals provide excellent strategy for sensing,catalysis or photonics,the construction of innovative interfaces and development of versatile strategies for nanocrystal synthesis are urgently needed.Herein,latent fingerprints(LFPs),the most common markers for human identity,are used as naturally accessible interface for organization of graphene isolated nanocrystals(GINs).Excitingly,the selective adsorption of GINs on lipidic ridge provides a universal approach for the in-situ construction of the plasmonic arrays.Such system with intrinsic chrominance and Raman signal enables the high resolution colorimetric and surfaced-enhanced Raman spectroscopy(SERS)dual-mode imaging,which can detail the structures of the LFPs from 1st to 3rd level even the LFPs are shielded.Furthermore,the interface can be constructed on diverse materials by a simple finger-pressing process and the densely packed arrays can serve as superior SERS substrate for label-free,non-invasive acquisition of molecule information especially residues in LFPs.The combination of chemical composition with detailed structures efficiently recognizes the human identity and could help link it to a crime scene.Overall,the LFPs can act as natural platform for interface mediated localized assembly and personalized information acquisition for forensic science or precise medicine.

A Magnetocatalytic Propelled Cobalt-Platinum@Graphene Navigator for Enhanced Tumor Penetration and Theranostics

Complex biological environments and multiple physiological barriers significantly impede efficient accumulation and penetration of nanomaterials within tumor tissue for therapy.In situ energy conversion of nanomotors features autonomous movements and improves cancer treatment.However,one of the key challenges is to prepare nanomotors with an adequately small size,good biocompatibility,and precise positioning.Herein,we demonstrate a simple,ultrasmall,versatile,and real-time motion guidance strategy for magnetocatalytic CoPt@graphene navigators(MCGNs)that can enable highly efficient propulsion in the presence of H_(2)O_(2) or magnetic actuation.MCGNs act as highly diffusive delivery vehicles to promote tumor tissue targeting,and the amount of drug in the tumor was three times than without navigation.By engaging movements powered through in situ energy conversion,MCGNs gain considerable propulsion to penetrate a cell’s membrane and enhance intracellular delivery.

Hydrogen-Bonding-Induced H-Aggregation of Charge-Transfer Complexes for Ultra-Efficient Second Near-Infrared Region Photothermal Conversion

Aggregation plays a critical role in modulating the photophysical process of organicmolecules.However,the rational control of the construction of a functionoriented stacking mode for efficient photothermal(PT)conversion in the second near-infrared region(NIR-II;1000-1700 nm)remains a challenge.Herein,an H-aggregation of 3,3′,5,5′-Tetramethylbenzidine(TMB)-TMB dication(TMB++)complexes in linear agarose(H-TTC/LAG)with narrowed band gap(0.96 eV)was fabricated through intermolecular hydrogenbonding interactions between the amino groups of TTC and the peripheral hydroxyl groups of LAG.Charge-transfer mechanism and H-aggregation ensured NIR-Ⅱ absorption of the complex at>1400 nm.The H-aggregation also promoted a non-radiation relaxation pathway and improved the thermal stability of TTC,which together favored the constructed H-TTC/LAG with ultra-efficient PT conversion that increased rapidly to 140℃ in 15 s under the NIR-Ⅱ laser(1064 nm,1.0 W cm^(−2))irradiation.Such a unique H-TTC/LAG with good biocompatibility was used to demonstrate a superior PT therapy via high-efficie ncy tumor growth inhibition in mouse mammary carcinoma(4T1)the BALB/c mice tumor-bearing xenografts.This is the first established H-aggregation of charge-transfer complexes in a noncovalent system,which not only provides a new strategy to develop ultra-efficient NIR-Ⅱ PT materials but also paves the way for constructing functional materials with aggregates of charge-transfer complexes.