Multifunctional Biological Nanomaterials For Cell Apoptosis And Electrochemical Cytosensing

Nanohybrids,composed of organic and inorganic components,are endowed with favorable physicochemical properties and popular in the realm of biorelated systems,such as biosensor and drug delivery.The intrinsic capatilities of organic and inorganic parts have been integrated in one carrier or system and can be expected to produce novel and promosing functions,such as desirable optical,magnetic,and electrical properties.It is different between nanohybrids and bulk materials in clinical practice,which shows an outstanding application.Nowadays,individualized treatment became mainstream,and new requirements and challenges are presented for the framework construction of treatment system and efficacy evaluation.Multi-functional biological nano-heterogeneous materials integrate the characteristics of polymer,metal,semiconductor and other materials and combine with biomedical molecules to give them corresponding functions of biometrics and targeted therapy,which is the cornerstone of the new generation of diagnosis and treatment evaluation system with a broad prospect.This paper is cycled on how to build a multifunctional biological nano-heterogeneous system rationally,and be applied to proapoptosis-based cancer treatment,monitoring and efficacy evaluation.The research of apoptosis-related cancer cell system involving light,heat,chemotherapy have been developed and a new generation of biosensing applied to photo,electrochemical diagnosis and monitor of apoptosis.The main results were summarized as follow:1.Sequential Delivery and Cascade Targeting of Peptide Therapeutics for Triplexed Synergistic Therapy with Real-Time Monitoring Shuttled by Magnetic Gold NanostarsDue to the outstanding synergistic effects and low-toxicity,combination therapy exhibits more considerable potential in antitumor activity than monotherapy.Herein,a core-shell magnetic gold nanostar(Fe₃O₄@GNS,MGNS)-based system for codelivery of a mitochondrial targeting amphipathic tail-anchoring peptide(ATAP)and a membrane-associated cytokine(tumor-necrosis-factor-related apoptosis-inducing ligand(TRAIL)was constructed.The magnetic core can facilitate delivery of the drug vehicle by external magnetic field,which results in accurate accumulation and enhances tumor cellular uptake for preliminary targeting.TRAIL and ATAP could sequentially target and be released toward the plasma membrane and mitochondria,initiating the extrinsic and intrinsic apoptosis pathways,respectively.The gold shell of MGNS can cause local tumor hyperthermia due to broad-band plasmon resonances in the near-infrared region,which can act as a complement with the peptide drug to further enhance apoptosis.Both in vitro and in vivo experiments revealed that rationally integrating extrinsic apoptosis,intrinsic apoptosis and hyperthermia for triplexed synergistic therapy,enabled the smart drug vehicle with pinpoint peptide drug delivery capabilities,and minimized side effects,enhancing the antitumor efficiency.2.Peptide-Based Photoelectrochemical Cytosensor Using a Hollow-TiO₂/EG/ZnIn₂S₄Cosensitized Structure for Ultrasensitive Detection of Early Apoptotic Cells and Drug EvaluationThe ability to rapidly detect apoptotic cells and accurately evaluate therapeutic effects is significant in cancer research.To address this target,a biocompatible,ultrasensitive photoelectrochemical(PEC)cytosensing platform was developed based on electrochemically reduced graphene(EG)/ZnIn₂S₄cosensitized TiO₂coupled with specific recognition between apoptotic cells and phosphatidylserine-binding peptide(PSBP).In this strategy,the HL-60cells were selected as a model and C005,nilotinib,and imatinib were selected as apoptosis inducers to show cytosensing performances.In particular,a TiO₂photoactive substrate was designed as hollow spheres to enhance the PEC performance.Graphene was electrodeposited on the hollow TiO₂-modified electrode to accelerate electron transfer and increase conductivity,followed by in situ growth of ZnIn₂S₄nanocrystals as photosensitizers via successive ionic layer adsorption and reaction method,forming a TiO₂/EG/ZnIn₂S₄cosensitized structure that was used as a PEC matrix to immobilize PSBP for the recognition of early apoptotic cells.The detection of apoptotic cells was based on steric hindrance originating from apoptotic cell capture to induce an obvious decrease in the photocurrent signal.The ultrahigh sensitivity of the cytosensor resulted from enhanced PEC performance,bioactivity,and high binding affinity between PSBP and apoptotic cells.Compared with other assays,incorporate toxic elements were avoided,such as Cd,Ru,and Te,which ensured normal cell growth and are appropriate for cell analysis.The designed PEC cytosensor showed a low detection limit of apoptotic cells(as low as three cells),a wide linear range from 1×10³to 5×10⁷cells/m L,and an accurate evaluation of therapeutic effects.It also exhibited good specificity,reproducibility,and stability.3.In-Situ Modified Flexible Conductive Polymer Hydrogels-Based Sensor for Growth and Direct Electrical Monitor of Living CellsBoth long-term cell growth and real-time,accurate electrical cell monitor are important in physiological investigation,putting forward higher demands on the processability,operability,repeatability,performance and biocompatibility of electrochemical(EC)sensors.Based on the nanostructured conductive polymer hydrogels(CPHs),we proposed an efficient and versatile strategy to construct an in-situ modified three-dimensional(3D)flexible EC sensor for cell analysis.Flexible 3D carbon fiber substrate was selective as the current collector to promote the operability and repeatability of sensor fabrication.In-situ generated3D polyporous nanostructure of conductive polymer hydrogels are favorable for Pt nanoparticle loading,cell growth,electron exchanging,and enhanced mass transferring.With these 3D nanostructured features,the hydrogel EC platform was endowed with high-sensitivity and selectivity in the detection of H₂O₂(with a low detection limit of 1.6?M in 0.01 M PBS and a wide linear range from 10?M to 15 m M),and good biocompatibility suitable for cell growth for as long as 5 days.The accurate detection of H₂O₂released from cells enabled us to differentiate the growth states of cells and imitate the different stimuli-responsive,which can provide in-depth information on cell biological events.With outstanding biocompatibility,operability and repeatability,the strategy can be expanded to other CHPs-based sensor fabrication and cell-related biomarker monitor,which exhibits a broad application potential in bioanalysis catering to new generation sensors.