3D spiral channels combined with flexible micro-sieve for high-throughput rare tumor cell enrichment and assay from clinical pleural effusion samples

The sieving and enrichment of rare tumor cells from large-volume pleural effusion(PE)samples is a promising technique for cell-based lung tumor diagnosis and drug tests,which features high throughput and recovery,purification,as well as viability rates of rare target cells as the prerequisites for high sensitivity,specificity,and accuracy of tumor cell analysis.In this paper,we propose a three-dimensional(3 D)sieving method for rare tumor cell enrichment,which effectively eliminates the"dead zones"in traditional two-dimensional(2 D)cell filters with a dimension-raising strategy to satisfy the requirements mentioned above.The prototype device was combined with a funnel-shaped holder,a flexible micropore membrane in the middle,and a3 D spiral fluid channel covered on the membrane as a three-layer ice-creaming cone composite structure.Driven by gravity alone,the device performed as follows:(1)20-fold throughput compared with the 2 D commercial planee hich was up to 20 mL/min for a threefold dilution of whole blood sample;(2)high recovery rates of 84.5%±21%,86%±25%,83%±14%for 100,1000,and 10000 cells/mL,respectively,in 30 mL phosphate buffer saline(PBS)sample,and a 100%positive detection rate in the case of≤5 A549 cells in 1 mL PBS;(3)a typical purification rate of 85.5%±9.1%;and(4)a viability rate of>93%.In the demonstration application,this device effectively enriched rare target cells from large volumes(>25 mL)of clinical pleural effusions.The following results indicated that tumor cells were easy-to-discover in the enriched PE samples,and the proliferation capability of purified cells was(>4.6 times)significantly stronger than that of unprocessed cells in the subsequent 6-day culture.The above evaluation indicates that the proposed easily reproducible method for the effective execution of rare cell enrichments and assays is expected to become a practical technique for clinical cell-based tumor diagnosis.

Honeycomb-like MXene/NiFeP_(x)–NC with“continuous”single-crystal enabling high activity and robust durability in electrocatalytic oxygen evolution reactions

The development of low-cost,stable,and robust non-noble metal catalysts for water oxidation is a pivotal challenge for sustainable hydrogen production through electrocatalytic water splitting.Currently,such catalysts suffer from high overpotential and sluggish kinetics in oxygen evolution reactions(OERs).Herein,we report a“continuous”single-crystal honeycomb-like MXene/NiFeP_(x)–N-doped carbon(NC)heterostructure,in which ultrasmall NiFeP_(x)nanoparticles(NPs)encapsulated in the NC are tightly anchored on a layered MXene.Interestingly,this MXene/NiFeP_(x)–NC delivers outstanding OER catalytic performance,which stems from“continuous”single-crystal characteristics,abundant active sites derived from the ultrasmall NiFeP_(x)NPs,and the stable honeycomb-like heterostructure with an open structure.The experimental results are rationalized theoretically(by density functional theory(DFT)calculations),which suggests that it is the unique MXene/NiFeP_(x)–NC heterostructure that promotes the sluggish OER,thereby enabling superior durability and excellent activity with an ultralow overpotential of 240 mV at a current density of 10 mA×cm^(−2).

Through-polymer,via technology-enabled,flexible,lightweight,and integrated devices for implantable neural probes

In implantable electrophysiological recording systems,the headstage typically comprises neural probes that interface with brain tissue and integrated circuit chips for signal processing.While advancements in MEMS and CMOS technology have significantly improved these components,their interconnection still relies on conventional printed circuit boards and sophisticated adapters.This conventional approach adds considerable weight and volume to the package,especially for high channel count systems.To address this issue,we developed a through-polymer via(TPV)method inspired by the through-silicon via(TSV)technique in advanced three-dimensional packaging.This innovation enables the vertical integration of flexible probes,amplifier chips,and PCBs,realizing a flexible,lightweight,and integrated device(FLID).The total weight of the FLIDis only 25%that of its conventional counterparts relying on adapters,which significantly increased the activity levels of animals wearing the FLIDs to nearly match the levels of control animals without implants.Furthermore,by incorporating a platinum-iridium alloy as the top layer material for electrical contact,the FLID realizes exceptional electrical performance,enabling in vivo measurements of both local field potentials and individual neuron action potentials.These findings showcase the potential of FLIDs in scaling up implantable neural recording systems and mark a significant advancement in the field of neurotechnology.