Zhen Cao

Single-cell transfection technologies hold tremendous promise for precision cell and immunotherapies. However, monolithic integration of cell isolation with targeted intracellular delivery remains technically challenging, especially within complex biological matrices. Herein, we present a microcapillary-assisted acoustoelectric single-cell selective isolation and sonoporative transfection platform (μC-ASSIST), which seamlessly sequences microcapillary-assisted dielectrophoresis (μC-DEP) for deterministic single-cell trapping with high-frequency surface acoustic waves (SAWs) for transient membrane poration within a unified workflow. We demonstrate the label-free, high-efficiency extraction of human non-small cell lung cancer (A549) cells from a complex white blood cell (WBC) background with a capture efficiency of 95%. Furthermore, we validate the highly efficient, contact-free intracellular delivery of diverse cargoes ranging from small dyes (PI) to functional small interfering RNA (siRNA) and large plasmid DNA (mRFP-C3), maintaining a high cell viability of 83.7% alongside a 78.1% transfection efficiency. Crucially, the targeted delivery of siBcl-xL significantly suppressed target mRNA expression and profoundly inhibited tumor cell motility. By circumventing off-target effects and cumbersome manual handling, the μC-ASSIST platform establishes a highly versatile, streamlined paradigm for precision single-cell engineering, holding immense potential for advancing functional genomics and next-generation gene therapies.

Acute compartment syndrome (ACS) requires timely diagnosis, delayed diagnosis can cause irreversible neuromuscular injury, limb loss, and even death, whereas current diagnosis still relies on subjective examination and intermittent invasive pressure measurements. Here, we report an injectable, biodegradable biotelemetric implant for accurate, continuous wireless monitoring of intracompartmental pressure (IcP), and further establish a predictive model that converts pressure-duration signals into quantitative assessment of ACS progression, providing a clinically relevant framework for diagnosis and intervention. Our platform integrates an ultraminiaturized iontronic pressure transducer as the implant with a parity-time symmetric wireless readout circuit, enabling precise sensing and mapping of pressure-time load onto a two-dimensional ACS matrix for quantitative prediction of disease progression. The device functions throughout the clinically relevant monitoring window and then degrades naturally, eliminating the need for retrieval surgery. This work offers a transient, minimally invasive strategy for continuous ACS surveillance, and highlights the translational potential of biodegradable implantable bioelectronics for trauma care.

This work numerically reveals a novel strategy to modulate two ionic conductance state in a nanochannel via pressure-dependent fluidic motion inside the channel. Steady and transient simulations based on Poisson–Nernst–Planck–Stokes equations demonstrate that the two states with distinct ionic conductance and ion selectivity can be reversibly switched by external pressure, with a characteristic time of ~100 μs. Furthermore, the two conductance states are found to depend on the transversal electric field, which gives rise to two distinct intrachannel fluidic flow patterns, namely laminar flow and vortex flow, respectively. This finding suggests the potential of pressure-controlled ionic conductance switching for applications in nanofluidic ionic circuits, flow-regulated sensing, and integrated micro/nanoscale devices. It also provides insights into nonlinear ionic current–voltage behaviors.

The implantable neural probe for simultaneous recording of various brain signals is one of the key technologies for neurological science and clinics that is yet to be broken through. Here, we introduce an implantable neural probe with integrated carbon nanotube field-effect transistors which is able to perform multimodal recording of electrical and chemical signals of the brain under magnetic resonance imaging (MRI). We demonstrate here a simultaneous measurement of an electrophysiological signal with high signal-to-noise ratio up to 40.34 dB and calcium concentration with a detection limit down to 0.47 nM. We use our neural probes to detect neural activity in rats and results reveal that changes in Ca²⁺ concentration occur concurrently with the epileptiform local field potential events, providing an alternative method for accurate detection of epilepsy. Our work may provide a powerful means for the future studies of brain and holds great potential for practical diagnostic applications.

Cartilage degradation is a hallmark of osteoarthritis. Restoring the natural bioelectric environment of osteoarthritic tissue could offer a promising treatment strategy through physical modulation. We report a microsized, biodegradable implantable patch that utilizes a piezoelectric effect-enhanced triboelectric charge generator (PTEG) to promote cartilage regeneration and osteoarthritis healing. Featuring a triboelectric architecture with macroscopic pyramids and microscopic porosities, the PTEG patch produces a charge density of 242 μC m^-2 in vitro and 84 μC m^-2 in vivo, approximately 2 orders of magnitude higher than that of the state-of-the-art implantable charge generators. Additionally, the PTEG patch demonstrates excellent biocompatibility and tunable degradability. In vitro experiments show that the PTEG significantly promotes bone marrow stem cell migration, Ca²⁺ influx, and chondrogenic gene expression. In an osteoarthritis rat model, PTEG implantation was shown to reduce osteophyte formation and enhance cartilage regeneration significantly.

The long-term implantable neural probe for simultaneous recording of various brain signals is the key technology of neuro clinic applications that needs to be broken through. This paper introduces carbon nanotube field-effect transistor (CNTFET) into the neural science and demonstrated an implantable neural probe for multimodal recording of electrical and chemical brain signals under magnetic resonance imaging (MRI). The CNTFET source followers are monolithically integrated with the electrodes to enhance the signal-to-noise ratio (SNR) up to 40.34 dB across a wide acquisition bandwidth from 0.01-32 kHz. The neurotransmitter ion sensors constructed by CNTFET are also integrated for cocurrent detection of concentration of calcium ions (Ca²⁺) changing with a detection limit down to 0.46 nM. The MRI compatablity is verified under 7 Tsela scanner with reduced artifacts. The immunohistology confirms the excellent biocompatibility and the long-term effectiveness with a capability for continuous recording of electrical potentials and ion concentraions from a rat for 3 months without obvious brain inflammatory responses. Leveraging on our probes, changes in Ca²⁺ concentration can be observed to occur nearly concurrently with the epileptiform local field potential events in a rat model, suggesting a potential enhancement in epilepsy detection accuracy. Given the multimodal recording capability and MRI compatibility, together with easy integration schemes, our work provides a powerful scaffold for the the future brain study and holds great potentials for practical dignositc applications.