Self-healing Response Research Articles

Castor oil-based polyurethane Vitrimer modified asphalts regulated by dual dynamic reversible reactions and crosslinking density: Preparation, basic assessment and self-healing behavior

Thermosetting polymers, commonly used to improve asphalt properties, bring excellent pavement performance, but also pose significant challenges to the healing and recyclability of their modified asphalts after long-term service. An effective approach involves introducing dynamic bonds into the crosslinking networks to synthesize Vitrimer-modified asphalts with self-healing response. Due to the splendid mechanical properties, high elasticity, flexibility and easily controllable cross-linked structure of polyurethane, a novel castor oil-based polyurethane Vitrimer modified asphalt with disulfide bonds and Diels-Alder reactions was developed. Based on the prepared castor oil-based polyurethane Vitrimer (C-PUV, composed of components A and B) and its modified asphalts (C-PUVAs), a comprehensive study was conducted on the crosslinking density, mechanical properties, thermal stability, viscosity, compatibility, rheological properties, and self-healing behavior. The results indicated that C-PUVAs (C-PUVA1/C-PUVA2/C-PUVA3/C-PUVA4) exhibited sufficient retention times for viscosity, uniform phase distribution, and good high-temperature performance. The damaged C-PUVAs achieved a mechanical strength recovery rate more than 75 % after the first cycle of self-healing at 80 ℃ and 0.3 MPa. Furthermore, the crosslinking density of C-PUV was regulated by the segment length of component B. As the crosslinking density increased, C-PUV and C-PUVAs obtained higher mechanical strength while sacrificing part of self-healing efficiency. The mechanism is that increased crosslinking density altered the gel point distributions of the reversible crosslinked networks, resulting in a longer relaxation time and higher activation energy. In conclusion, the above findings provided valuable insights for developing bio-based polyurethane Vitrimer modified asphalts, and endosing thermosetting polymer modified asphalts with self-healing and recyclable properties.

A sustainable and self-healable silk fibroin nanocomposite with antibacterial and drug eluting properties for 3D printed wound dressings.

The development of self-healable and 3D printable hydrogels with decent biocompatibility, mechanical durability, adhesiveness to tissues, and antibacterial activity is of great importance for wound healing applications. In this study, we present a sustainable and environmentally friendly composite hydrogel consisting of silk fibroin (SF), oxidized salep (OS), and kappa carrageenan nanoparticles (NPs) for efficient wound care. The injectable nanocomposite hydrogel is highly stretchable and exhibits strong tissue adhesiveness and self-healing response through Schiff-base cross-linking between OS and SF. The tunable shear-thinning viscoelastic properties of the hydrogel facilitate 3D bioprinting with excellent shape adaptability (97.7 ± 1.1% recovery), enabling the fabrication of complex-shaped constructs. In vitro release kinetics of tetracycline (TC) encapsulated in kappa carrageenan NPs indicate a distinctive Korsmeyer-Peppas profile, including an initial burst release followed by a triphasic pattern controlled by the embedded NPs within the hydrogel matrix. The composite hydrogel shows a remarkable broad-spectrum antibacterial activity with substantial zones of inhibition against S. aureus (34.00 ± 1.00 mm) and E. coli (27.60 ± 2.08 mm) after 24 h of incubation at 37 °C. The addition of TC further enhances the zones of inhibition by approximately 45% for S. aureus and 27% for E. coli. The control group without kappa NP incorporation shows no zone of inhibition, underscoring the critical role of the nanoparticles in imparting antibacterial activity to the hydrogel. Cytocompatibility assays show the high viability of fibroblast (L929) cells (>90%) in vitro. In vivo biocompatibility studies through subcutaneous implantation also do not show malignancy, infection, abscess, necrosis, epidermal or dermal modifications, or inflammation of the wounds after 14 days post-injection. H&E staining shows that the biodegradation of the developed hydrogel facilitates the growth of non-inflammatory cells, leading to the substitution of the injected hydrogel with autologous tissue. The detailed analyses affirm that the multifunctional injectable hydrogel with self-healing and antibacterial properties has high potential for wound healing and skin tissue engineering.

Bioinspired self-healing nickel coating.

We present a study of self-healing mechanisms including their kinetics and thermodynamics in nickel coatings. The bioinspired self-healing coating is designed to enhance the durability of structural metal components exposed to harsh conditions. Microcapsules, reminiscent of natural healing reservoirs, were synthesized via in situ polymerization in an oil-in-water emulsion to encapsulate linseed oil, a healing agent, within poly(urea-formaldehyde) (PUF) shells. Nickel coatings incorporating PUF shell microcapsules were electrodeposited on mild steel substrates to assess their effectiveness in self-healing, mimicking nature's ability to provide on-demand healing. Comprehensive characterization of the microcapsules and coating was performed using techniques including Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Thermogravimetric Analysis (TGA). The self-healing performance of the coating was evaluated using SEM and EDS after scratches simulating damage were made on the surfaces of the samples. Corrosion resistance and self-healing ability were evaluated through an immersion test, and additional corrosion resistance tests such as Open Circuit Potential (OCP) and Linear Polarization (LP) were conducted. The results indicate that the nickel coating containing PUF shell microcapsules confers corrosion resistance to the substrate and, upon damage to that coating, induces a self-healing response analogous to natural systems, highlighting the potential of bioinspired designs in advanced material solutions.

Self-healing polymers for space: A study on autonomous repair performance and response to space radiation

One of the main challenges of space exploration is to properly protect astronauts from the hazards of the space environment. Space suits were hence created to protect crewmembers during extravehicular activities, but they are currently unable to properly withstand damage after, for example, impacts with micrometeoroids and orbital debris (MMOD), and they would depressurize and collapse if punctured, with catastrophic consequences. In this context, the possibility of integrating self-healing materials into spacesuits has drawn the attention of the scientific community, as it would lead to autonomous damage restoration and subsequently increased safety and operational life. Nevertheless, the effects of space environment on these materials are still to be determined and could lead to a significant decrease of their overall performance.The here presented study focuses on a first example of application to a space suit, analyzing the healing performance of a set of candidate self-healing polymers before and after exposure to simulated space radiation. A comparison of bilayers and nanocomposites having these polymers as matrices is also made in the non-irradiated case. This research also aims at filling the gap between standard characterization of self-healing materials (e.g.: scratch, impact, and puncture tests) and assessment of the effects of space radiation on them by combining these two aspects. Understanding if and how radiation can affect damage recovery performance is in fact fundamental to determine whether a given self-healing material can actually be used for space applications.The self-healing response is assessed through in-situ flow rate measurements after puncture damage. Maximum and minimum flow rate, the time between them and the air volume lost within the 3 min following puncture are collected as healing performance parameters. For the neat materials, the same tests are then repeated on gamma-ray irradiated samples to study the variation in self-repairing performance after exposure to simulated space radiation. Results show that the healing performance is higher in systems with lower viscous response and that it decreases after irradiation. A further analysis of the effects of space environment on the presented materials is hence required.The NASA HZETRN2015 (High Z and Energy TRaNsport, 2015 version) software is also used to simulate the action of galactic cosmic rays on the space suit during extravehicular activity. The classic suit multilayer is compared with configurations in which the standard bladder is replaced with a layer of each analyzed material to identify the most promising candidates and determine whether the addition of nanofillers significantly increases the shielding ability.

Topological effects of 3D-printed copolymer interlayers on toughening and in situ self-healing in laminated fiber-composites

Interlaminar delamination in fiber-reinforced composites limits structural capacity and service life. Delaminations, which occur subsurface and can lead to catastrophic failures, are hard to detect and repair. Contrasting traditional mitigation strategies (e.g., inspection, over-design), proactive toughening and responsive self-healing of damaged interfaces offer practical, cost-effective solutions. Our recently developed strategy to address interlaminar damage—3D-printed thermoplastic interlayers and structurally integrated heaters—has been shown to achieve composite toughening and in situ self-healing via thermal remending, abetting repeated repair and improved delamination resistance. Here, we leverage this latest thermal remending strategy to investigate the effects of 3D-printed pattern topology on damage resistance and self-healing response. The chief attributes are: (i) realizing up to 450% increase in mode-I fracture resistance, (ii) restoring up to 100% of the increased fracture resistance for ten consecutive healing cycles, and (iii) achieving in situ self-healing below the thermoset-matrix glass transition temperature, thereby preserving structural integrity during repair. The proposed damage mitigation strategy fosters structural reliability, reduces failure risk, and increases service lifetime—three essential attributes in meeting the multifaceted demands of modern composite infrastructure.

Self-healing master curves of bituminous binders: a non-linear viscoelastic continuum damage framework

In this paper the viscoelastic continuum damage theory was used to investigate the damage and self-healing potential of bituminous binders, considering the effects of rest temperature, thixotropy, and non-linearity. Experimental testing was carried out by using a procedure in which continuous oscillatory shear loading was imparted to the specimens with the inclusion of a single rest period under multiple temperature conditions. Quantification of self-healing included the determination of material integrity gained and damage parameter recovered after the rest period. Such parameters were calculated by excluding time-dependent and non-linear biasing effects, which were directly evaluated by means of a distinct set of experiments. Results were modelled by using the so-called self-healing master curves, constructed by applying the linear viscoelastic time-temperature shift factors. These self-healing master curves are intended to be used as straightforward tools for the prediction of the self-healing response of neat and polymer modified binders in various time-temperature combinations.

Novel PA encapsulated PCL hybrid coating for corrosion inhibition of biodegradable Mg alloys: A triple triggered self-healing response for synergistic multiple protection

Novel PA encapsulated PCL hybrid coating for corrosion inhibition of biodegradable Mg alloys: A triple triggered self-healing response for synergistic multiple protection

IL-3 DISCONNECTING BRAIN TUMOR NETWORKS FOR IMPROVED THERAPIES

Abstract Integration into communicating tumor cell networks is a way how the entire brain tumor organism can progress in the brain, and resist therapies. It started with our discovery of ultra-long membrane protrusions, tumor microtube (TM), in tumor cells from glioblastomas and other incurable adult and pediatric glioma entities (Osswald et al., Nature 2015). These TMs are used for very effective brain invasion, and later interconnect single tumor cells to communicating and resistant multicellular networks, but also glioma cells to neurons in the brain, with neuron-glioma synapses stimulating glioma growth(Venkataramani et al., Nature 2019) and invasion (Venkataramani et al., Cell 2022). Increasing formation of these homotypic and heterotypic networks is seen with increasing glioma malignancy: lowest in low-grade oligodendrogliomas, and highest in glioblastomas and K27M mutated gliomas. The genetic reduction of GAP-43, a crucial neurodevelopmental factor that drives TM formation and function, not only deprived glioblastoma cells from the ability to form functional tumor networks, but also made radiotherapy much more effective, by and large eradicating experimental tumors from the mouse brain, which is typically not possible with radiotherapy alone. Consistent with the concept of tumor cell resilience by network integration, radiotherapy and also chemotherapy (Weil et al., Neuro-Oncology 2017) preferentially killed the unconnected glioblastoma cells, leaving the tumor cell networks largely intact. Damage to the tumor network by surgical measures induced a self-healing response. Taken together, integration into multicellular, highly functional, communicating and resilient networks is not only a feature of the nervous system, but also of incurable, most aggressive brain tumors. In this talk, clinical concepts that originate from these discoveries are presented, including a network disconnection strategy currently tested in the German MecMeth trial (EudraCT2021-000708-39), and the AMPAR inhibitor perampanel as a potential inhibitor of neuron-glioma synapses. Furthermore, new basic and translational developments in the field of brain tumor networks are presented and discussed.

Rheology and self-healing of amine functionalized polyolefins

The rheological and self-healing behavior of a class of catalytically synthesized amine-functionalized polyolefins is investigated. We demonstrate that these materials possess tunable rheological properties according to the molecular weight and display autonomous self-healing. The linear viscoelastic properties are modeled using a tube-based model developed by Hawke et al. [J. Rheol., 60, 297–310, (2016)] to calculate several model parameters that describe the individual chain dynamics. The self-healing response is described by findings from the reptation model as well as recent theory on associating polymer networks with reversible bonds. The cooperation between experiments, modeling, and theory provide insight into designing new materials with programmable rheological properties and superior self-healing ability.

Texture and rheological features of strain and pH sensitive chitosan-imine graphene-oxide composite hydrogel with fast self-healing nature

Here we report a smart Chitosan-isophthalaldehyde-Graphene oxide (CS-ISD-GO) hydrogel as a “multicomponent hydrogel”. We witnessed an unprecedented pH responsive changes in viscoelasticity, stretchability, adhesiveness, self-healing and self-adaptability upon changing the pH and concentration of CS and ISD that was authenticated by texture and rheological analysis. The GO provides physical crosslinks and antibacterial properties to the hydrogel. Taking the advantage of dynamic nature of covalent and non-covalent interactions, we tuned the hydrogel adhesion and stretchability in response to the pH changes. Further self-healing of hydrogels was fully investigated by measuring thixotropic response over more than three cycles of strain sweep and real time optical imaging and video recording techniques. The recorded videos display 100 % self-healing response within a time frame of 2–6 min. These properties were observed only over small range of pH (4.5–5.5). The hydrogel becomes mechanically strong above pH 5.5 and becomes unstable above pH 7 leading to subsequent disintegration. The characterization of hydrogel was carried by FTIR, FESEM and TGA analysis. In addition, the hydrogel was reduced using NaBH4 for drug release. The reduced gel appears to be stable at lower pH values also. The reduced hydrogel may potentially be used for drug release purpose with low toxicity.

Self-Healability of Poly(Ethylene-co-Methacrylic Acid): Effect of Ionic Content and Neutralization.

Self-healing polymers such as poly(ethylene-co-methacrylic acid) ionomers (PEMAA) can heal themselves immediately after a projectile puncture which in turn lowers environmental pollution from replacement. In this study, the thermal-mechanical properties and self-healing response of a library of 15 PEMAA copolymers were studied to understand the effects of the ionic content (Li, Na, Zn, Mg) and neutralization percentage (13 to 78%) on the results. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tensile testing were used to study the thermo-mechanical properties of PEMAA copolymers while the self-healing response was studied using the projectile test. Puncture sites were observed using scanning electron microscopy (SEM) and the healing efficiency was quantitatively measured using the water leakage test. Five different self-healing responses were observed and correlated to ionic content and neutralization. At high neutralization, divalent neutralizing ions (Zn and Mg) that have stronger ionic interactions exhibited brittle responses during projectile testing. PEMAA samples neutralized with Mg and Li at low concentrations had a higher healing efficiency than PEMAA samples neutralized with Zn and Na at low neutralization. The PEMAA copolymers with higher tensile stress and two distinct peaks in the graph of loss factor versus temperature that indicate the presence of sufficient ionic aggregate clusters had improved healing efficiency. By increasing the neutralization percentage from 20% to 70%, the tensile strength and modulus of the samples increased and their self-healability generally increased. Among the investigated samples, the copolymer with ~50% neutralization by Li salt showed the highest healing efficiency (100%). Overall, the strength and elastic response required for successful self-healing responses in PEMAA copolymers are shown to be governed by the choice of ion and the amount of neutralization.

INSP-13. Malignant networks in brain tumors: from basic discoveries to clinical implications

Abstract Integration into communicating tumor cell networks is a way how the entire brain tumor organism can progress in the brain, and resist therapies. It started with our discovery of ultra-long membrane protrusions, tumor microtube (TM), in tumor cells from glioblastomas and other incurable adult and pediatric glioma entities (Osswald et al., Nature 2015). These TMs are used for early brain invasion, and later interconnect single tumor cells to communicating and resistant multicellular networks, but also glioma cells to neurons in the brain, with neuron-glioma synapses stimulating glioma progression (Venkataramani et al., Nature 2019). Increasing formation of these homotypic and heterotypic networks is seen with increasing glioma malignancy: lowest in low-grade oligodendrogliomas, and highest in glioblastomas and K27M mutated gliomas. The genetic reduction of GAP-43, a crucial neurodevelopmental factor that drives TM formation and function, not only deprived glioblastoma cells from the ability to form functional tumor networks, but also made radiotherapy much more effective, by and large eradicating experimental tumors from the mouse brain, which is typically not possible with radiotherapy alone. Consistent with the concept of tumor cell resilience by network integration, radiotherapy and also chemotherapy (Weil et al., Neuro-Oncology 2017) preferentially killed the unconnected glioblastoma cells, leaving the tumor cell networks largely intact. Damage to the tumor network by surgical measures induced a self-healing response. Taken together, integration into multicellular, highly functional, communicating and resilient networks is not only a feature of the nervous system, but also of incurable, most aggressive brain tumors. In this talk, clinical concepts that originate from these discoveries are presented, including a network disconnection strategy currently tested in the German MecMeth trial (EudraCT2021-000708-39), and the AMPAR inhibitor perampanel as a potential inhibitor of neuron-glioma synapses. Furthermore, new basic and translational developments in the field of brain tumor networks are presented and discussed.

Research Progress in Environmental Response of Fiber Concrete and Its Functional Mechanisms

Smart fiber reinforced concretes (FRC) are good in intelligent environmental response. With the smart FRC being used in buildings such as bridges and tunnels, the real-time online distributed monitoring of concrete state can be realized. It provides an excellent solution to reduce the emergencies caused by the accumulation of damages, resistance attenuation, etc. This paper analyzes smart FRC’s self-sensing and self-healing response characteristics under different environmental response fields. Furthermore, the intelligent response mechanism of smart carbon fiber reinforced concrete (CFRC), optical fiber reinforced concrete (OFRC), glass fiber reinforced concrete (GFRC), and nanofiber reinforced concrete (NFRC) would be summarized. The response fields include the stress field, temperature field, electromagnetic field, chemical field, and humidity field, among which the field response mechanism of smart NFRC is classified and summarized. Finally, the advantages and disadvantages, the intelligent response parameters, and the applications of smart FRC under different environmental fields are compared.

Isotropic pressure promoted collective self-healing response in granular molecular crystals

自愈合材料具有修复损坏并改善产品寿命、 安全性和功能的能力. 但自愈合效应在有序分子晶体中却很少被报道, 且自愈效率较低. 在本研究中, 我们首次报告了常温下N-甲基脲(NMU)晶体颗粒中各向同性压力触发的集体性自愈行为. 其中, 自愈率最高可以达到100%, 并伴随着“粉晶-单晶”转变. 自愈后的晶体会在更高压力作用下破裂, 并在卸压过程中再次愈合. 原位光学显微镜、 单晶X射线衍射、 粉末晶体X射线衍射和拉曼实验表明, 在0.3 GPa附近的各向异性相变和晶粒间的紧密接触是NMU晶体颗粒产生集体性自愈响应的两个先决条件. 该集体性自愈行为的高自愈率来源于在自愈合过程中外部压力被持续不断地消耗并转化为氢键重组的化学能, 这也为提高其他分子晶体中自愈合效率提供了思路.

Tuning the Self-Healing Response of Poly(dimethylsiloxane)-Based Elastomers

We present a comprehensive investigation of mechanical properties of supramolecular polymer networks with rationally developed multistrength hydrogen-bonding interactions. Self-healing poly(dimethy...

Photoacoustic visualization of the fluence rate dependence of photodynamic therapy.

This study investigates the fluence rate effect, an essential modulating mechanism of photodynamic therapy (PDT), by using photoacoustic imaging method. To the best of our knowledge, this is the first time that the fluence rate dependence is investigated at a microscopic scale, as opposed to previous studies that are based on tumor growth/necrosis or animal surviving rate. This micro-scale examination enables subtle biological responses, including the vascular damage and the self-healing response, to be studied. Our results reveal the correlations between fluence rate and PDT efficacy/self-healing magnitude, indicating that vascular injuries induced by high fluence rates are more likely to recover and by low fluence rates (≤126 mW/cm2) are more likely to be permanent. There exists a turning point of fluence rate (314 mW/cm2), above which PDT practically produces no permanent therapeutic effect and damaged vessels can fully recover. These findings have practical significance in clinical setting. For cancer-related diseases, the 'effective fluence rate' is useful to provoke permanent destruction of tumor vasculature. Likewise, the 'non effective range' can be applied when PDT is used in applications such as opening the blood brain barrier to avoid permanent brain damage.

Mesenchymal and Induced Pluripotent Stem Cells-Derived Extracellular Vesicles: The New Frontier for Regenerative Medicine?

Regenerative medicine aims to repair damaged, tissues or organs for the treatment of various diseases, which have been poorly managed with conventional drugs and medical procedures. To date, multimodal regenerative methods include transplant of healthy organs, tissues, or cells, body stimulation to activate a self-healing response in damaged tissues, as well as the combined use of cells and bio-degradable scaffold to obtain functional tissues. Certainly, stem cells are promising tools in regenerative medicine due to their ability to induce de novo tissue formation and/or promote organ repair and regeneration. Currently, several studies have shown that the beneficial stem cell effects, especially for mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs) in damaged tissue restore are not dependent on their engraftment and differentiation on the injury site, but rather to their paracrine activity. It is now well known that paracrine action of stem cells is due to their ability to release extracellular vesicles (EVs). EVs play a fundamental role in cell-to-cell communication and are directly involved in tissue regeneration. In the present review, we tried to summarize the molecular mechanisms through which MSCs and iPSCs-derived EVs carry out their therapeutic action and their possible application for the treatment of several diseases.

Treatment of Acute Proximal Anterior Cruciate Ligament Tears-Part 2: The Role of Internal Bracing on Gap Formation and Stabilization of Repair Techniques.

Background:The latest biomechanical studies on some form of internal bracing have shown improved stabilization for anterior cruciate ligament (ACL) repair, but gap formation and load-sharing function have not yet been reported.Hypothesis:Internal bracing of an adjustable ACL repair construct provides improved stabilization with reduced gap formation and higher residual loading on the ACL.Study Design:Controlled laboratory study.Methods:Internally braced ACL repair constructs with single– and double–cinch loop (CL) cortical buttons, a knotless suture anchor, and a single-CL cortical button with adjustable loop fixation (CLS-ALD) were tested (n = 20 each) in a porcine model at 4 different loads (n = 5 each) over 4000 cycles at 0.75 Hz (n = 80 total). The CLS-ALD technique allowed for additional preconditioning (10 cycles at 0.5 Hz). Test results of the isolated internal brace groups served as a baseline for comparison. Lastly, specimens were pulled to failure (50 mm/min) with a cut internal brace. Final loading and gap formation on the ACL repair construct as well as ultimate strength were analyzed.Results:A statistical significance for peak loads over peak elongation was found between the CLS-ALD and all other reinforced groups (analysis of covariance, P < .001). Accordingly, the adjustable repair technique showed improved load-bearing capability with the internal brace compared with all other fixed repair groups and revealed significantly higher loads than the knotted single-CL group. Also, significantly reduced gap formation was found for the CLS-ALD compared with all other groups (P < .001), with no gap formation up to 150 N with a final gap of 0.85 ± 0.31 mm at 350 N. A significantly higher ultimate failure load (866.2 ± 104.0 N; P < .001) was found for the button-fixed internal brace group compared with all other groups.Conclusion:Internal bracing had a crucial role in improving the stabilization potential of ACL repair at loads occurring during normal daily activity. The added strength of the internal brace allowed for reducing peak loads on the ACL repair construct as well as restricting gap formation to below 3 mm at loads up to 350 N.Clinical Relevance:Improvements in the mechanical characteristics of current ACL repair techniques that enable reduced gap formation and allow for early range of motion and accelerated rehabilitation may strengthen the self-healing response with the formation of stable scar tissue.

In-situ XAFS and SERS study of self-healing of passive film on Ti in Hank's physiological solution

The self-healing of passive film on Ti after being damaged in Hank's physiological solution greatly fluctuates with time and its mechanism has been investigated by in-situ X-ray absorption fine structure spectroscopy (XAFS) and surface enhanced Raman spectroscopy (SERS) in a novel electrochemical repassivation set-up. The self-healing response is instant and the current density decays within 50 s due to the increase of the ratio of O and Ti atoms. The increase of the coordination number of TiO contributes to the decrease of current density until 6000 s. Moreover, the in-situ structure evolution is vastly different from that of ex-situ. Two time-dependent adsorbed intermediates exist during self-healing, the adsorption layers of TiOHads and TiOH, and finally the interface forms a stable passive film of OTiOH after 1000 s with good corrosion resistance. Besides, in-situ XAFS and SERS exhibit a high disorder and amorphous nature of passive film on Ti, and the crystallinity increases from 300 s to 6000 s. Additionally, the time-dependent structure evolution and mechanism of self-healing of titanium passive film in local atomic scale will help to understand the corrosion science and protection in healthcare.

Living-Cell Imaging of Mitochondrial Membrane Potential Oscillation and Phenylalanine Metabolism Modulation during Periodic Electrostimulus.

Special electrosensory cells are sensitive to electric fields and give responses upon stimulation, but little is known about normal regular cells and cancerous cells. Herein, by designing nucleus- and mitochondria-targeting SERS nanoprobes combined with fluorescent monitoring of the mitochondrial membrane potential (MMP) variations, we found an interesting electrosensory and self-healing response in MMP within cancerous and normal cells during periodic impulse electrostimulation (IES). More importantly, the key regulator role of phenylalanine (phe) was revealed by cell fluorescent imaging and SERS detection, whose expression level was increased in response to IES to induce cell apoptosis. During IES off-state, the self-repair function of cells was activated to reduce phe release. We also found that cancerous cells (MCF-7 and HeLa cells) demonstrated a response more remarkable than that of normal cells (L929 and H8 cells) to periodic IES. Our finding revealed a common electrosensory and self-repair biofunction of cells and its related phe metabolism response. Understanding the difference of biophysical/electrophysiological responses between cancerous and normal cells may broaden the view for cancer therapy in the future.