Electroactive material-based biosensors for detection and drug delivery

Wearable biosensors for monitoring and as a predictive adjunct for patients at risk for ischemic cardiac-related injury

Despite increased attention and preventive efforts, the prevalence of major adverse cardiovascular events continues to rise, resulting in profound concerns for both the individual and the population at large. Rapidly evolving biotechnologies, micro-computerization, communication, and battery design have led to widespread commercial adoption, use, and dependence on smart devices, and, more recently, biosensors. Currently worn and carried, smart devices such as mobile phones and smart watches possess impressive computational and communication capabilities, monitoring a variety of biometrics such as heart rate, blood pressure, and cardiac rhythm. Several promising biomarkers have been identified that are expressed early in the development of cardiac injury. Biosensors that can assay multiple variants are now described, obviating the limitations generally attributed to dependence upon a single biomarker. Employing mathematical modeling along with intelligent learning capabilities complements and augments their potential value. Data derived from wearable multivariate biosensors linked to already worn smart devices can communicate information to protected settings with enhanced computational capability and cogency by evaluating relayed biometrics and early expressed biomarkers as well as trending data, improving sensitivity and specificity. Integrating intelligent learning capabilities can further power these efforts with beneficial impact on individuals and groups at risk, yielding great promise as monitoring and predictive adjuncts. Future derivations might, for those of particular concern, be linked to critical drug delivery and interventional systems.

Cancer theragnostics: closing the loop for advanced personalized cancer treatment through the platform integration of therapeutics and diagnostics

Cancer continues to be one of the leading causes of death worldwide, and conventional cancer therapies such as chemotherapy, radiation therapy, and surgery have limitations. RNA therapy and cancer vaccines hold considerable promise as an alternative to conventional therapies for their ability to enable personalized therapy with improved efficacy and reduced side effects. The principal approach of cancer vaccines is to induce a specific immune response against cancer cells. However, a major challenge in cancer immunotherapy is to predict which patients will respond to treatment and to monitor the efficacy of the vaccine during treatment. Theragnostics, an integration of diagnostic and therapeutic capabilities into a single hybrid platform system, has the potential to address these challenges by enabling real-time monitoring of treatment response while allowing endogenously controlled personalized treatment adjustments. In this article, we review the current state-of-the-art in theragnostics for cancer vaccines and RNA therapy, including imaging agents, biomarkers, and other diagnostic tools relevant to cancer, and their application in cancer therapy development and personalization. We also discuss the opportunities and challenges for further development and clinical translation of theragnostics in cancer vaccines.

Hydrogel-Gated MXene-Graphene Field-Effect Transistor for Selective Detection and Screening of SARS-CoV-2 and E. coli Bacteria

Field-effect transistor (FET) biosensors have significantly attracted interest across various disciplines because of their high sensitivity, time-saving, and label-free characteristics. However, it remains a grand challenge to interface the FET biosensor with complex liquid media. Unlike standard liquid electrolytes containing purified protein content, directly exposing FET biosensors to complex biological fluids introduces significant sensing noise, which is caused by the abundance of nonspecific proteins, viruses, and bacteria that adsorb to the biosensor surfaces. In this work, we leverage the hydrogel encapsulation on an MXene-graphene-based FET, which selectively allows the permeation of viruses (e.g., SARS-CoV-2) and bacteria (e.g., E. coli), leading to the high-specificity detection of those biomarkers. The results demonstrated that hydrogel encapsulation could successfully detect the SARS-CoV-2 biomarker at 1 fg/mL while preventing the diffusion of E. coli biomarkers, and the obtained signal output amplitude is twice that of sensors without hydrogel encapsulation, demonstrating significant advantages over conventional bare sensors.

Recent advances in polymer-based thin-film electrodes for ECoG applications

Electrocorticography (ECoG) has garnered widespread attention owing to its superior signal resolution compared to conventional electroencephalogram (EEG). While ECoG signal acquisition entails invasiveness, the invasive rigid electrode used inevitably inflicts damage on brain tissue. Polymer electrodes that combine conductivity and transparency have garnered great interest because they not only facilitate high-quality signal acquisition but also provide additional insights while preserving the health of the brain, positioning them as the future frontier in the brain-computer interface (BCI). This review summarizes the multifaceted functions of polymers in ECoG thin-film electrodes for the BCI. We present the abilities of sensitive and structural polymers focusing on impedance reduction, signal quality improvement, good flexibility, and transparency. Typically, two sensitive polymers and four structural polymers are analyzed in detail in terms of ECoG electrode properties. Moreover, the underlying mechanism of polymer-based electrodes in signal quality enhancement is revealed. Finally, the remaining challenges and perspectives are discussed.

MXene Hydrogels for Soft Multifunctional Sensing: A Synthesis-Centric Review

Intelligent wearable sensors based on MXenes hydrogels are rapidly advancing the frontier of personalized healthcare management. MXenes, a new class of transition metal carbon/nitride synthesized only a decade ago, have proved to be a promising candidate for soft sensors, advanced human-machine interfaces, and biomimicking systems due to their controllable and high electrical conductivity, as well as their unique mechanical properties as derived from their atomistically thin layered structure. In addition, MXenes' biocompatibility, hydrophilicity, and antifouling properties render them particularly suitable to synergize with hydrogels into a composite for mechanoelectrical functions. Nonetheless, while the use of MXene as a multifunctional surface or an electrical current collector such as an energy device electrode is prevalent, its incorporation into a gel system for the purpose of sensing is vastly less understood and formalized. This review provides a systematic exposition to the synthesis, property, and application of MXene hydrogels for intelligent wearable sensors. Specific challenges and opportunities on the synthesis of MXene hydrogels and their adoption in practical applications are explicitly analyzed and discussed to facilitate cross gemination across disciplines to advance the potential of MXene multifunctional sensing hydrogels.

Engineering Stimuli-Responsive Materials for Precision Medicine

Over the past decade, precision medicine has garnered increasing attention, making significant strides in discovering new therapeutic drugs and mechanisms, resulting in notable achievements in symptom alleviation, pain reduction, and extended survival rates. However, the limited target specificity of primary drugs and inter-individual differences have often necessitated high-dosage strategies, leading to challenges such as restricted deep tissue penetration rates and systemic side effects. Material science advancements present a promising avenue for these issues. By leveraging the distinct internal features of diseased regions and the application of specific external stimuli, responsive materials can be tailored to achieve targeted delivery, controllable release, and specific biochemical reactions. This review aims to highlight the latest advancements in stimuli-responsive materials and their potential in precision medicine. Initially, we introduce disease-related internal stimuli and capable external stimuli, elucidating the reaction principles of responsive functional groups. Subsequently, we provide a detailed analysis of representative pre-clinical achievements of stimuli responsive materials across various clinical applications, including enhancements in the treatment of cancers, injury diseases, inflammatory diseases, infection diseases, and high-throughput microfluidic biosensors. Finally, we discuss some clinical challenges, such as off-target effects, long-term impacts of nano-materials, potential ethical concerns, and offer insights into future perspectives of stimuli-responsive materials.

Tear-Based Ocular Wearable Biosensors for Human Health Monitoring

Wearable tear-based biosensors have garnered substantial interest for real time monitoring with an emphasis on personalized health care. These biosensors utilize major tear biomarkers such as proteins, lipids, metabolites, and electrolytes for the detection and recording of stable biological signals in a non-invasive manner. The present comprehensive review delves deep into the tear composition along with potential biomarkers that can identify, monitor, and predict certain ocular diseases such as dry eye disease, conjunctivitis, eye-related infections, as well as diabetes mellitus. Recent technologies in tear-based wearable point-of-care medical devices, specifically the state-of-the-art and prospects of glucose, pH, lactate, protein, lipid, and electrolyte sensing from tear are discussed. Finally, the review addresses the existing challenges associated with the widespread application of tear-based sensors, which will pave the way for advanced scientific research and development of such non-invasive health monitoring devices.

Recent advances in gold nanoparticles-based biosensors for tuberculosis determination

Tuberculosis (TB) is one of the major killer diseases affecting lung parenchymal tissues. Mycobacterium tuberculosis (Mtb) is the bacterium that causes it. It most commonly affects the lungs, although it can affect any part of the body, including the stomach, glands, bones, and nervous system. Although anti-mycobacterial drugs are available, it remains a major threat to public health due to the rise of drug-resistant strains, and early and accurate diagnosis is very important. Currently, research science and medical communities are focusing on the use of cost-effective biosensors to manage human biological processes and assess accurate health diagnostics. Due to their high sensitivity in chemical and biological assays, nanomaterials have been considered in the field of biosensors for better diagnosis, and among them, gold nanoparticles (AuNPs) can play an important role in accelerating the diagnosis of TB. Superior biocompatibility, conductivity, catalytic properties, high surface-to-volume ratio, and high density enable their widespread use in the fabrication of biosensors. This review evaluates the diagnostic accuracy of AuNP-based biosensors for the detection of Mtb. According to different transducers of biosensors, their structure, performance, advantages and limitations are summarized and compared. Moreover, the upcoming challenges in their analytical performance have been highlighted and the strategies to overcome those challenges have been briefly discussed.

From electricity to vitality: the emerging use of piezoelectric materials in tissue regeneration

The unique ability of piezoelectric materials to generate electricity spontaneously has attracted widespread interest in the medical field. In addition to the ability to convert mechanical stress into electrical energy, piezoelectric materials offer the advantages of high sensitivity, stability, accuracy and low power consumption. Because of these characteristics, they are widely applied in devices such as sensors, controllers and actuators. However, piezoelectric materials also show great potential for the medical manufacturing of artificial organs and for tissue regeneration and repair applications. For example, the use of piezoelectric materials in cochlear implants, cardiac pacemakers and other equipment may help to restore body function. Moreover, recent studies have shown that electrical signals play key roles in promoting tissue regeneration. In this context, the application of electrical signals generated by piezoelectric materials in processes such as bone healing, nerve regeneration and skin repair has become a prospective strategy. By mimicking the natural bioelectrical environment, piezoelectric materials can stimulate cell proliferation, differentiation and connection, thereby accelerating the process of self-repair in the body. However, many challenges remain to be overcome before these concepts can be applied in clinical practice, including material selection, biocompatibility and equipment design. On the basis of the principle of electrical signal regulation, this article reviews the definition, mechanism of action, classification, preparation and current biomedical applications of piezoelectric materials and discusses opportunities and challenges for their future clinical translation.

One pot fabrication of diamino naphthalene -AuNPs decorated graphene nanoplatform for the MRSA detection in the biological sample

Early monitoring of MRSA can effectively mitigate the disease risk by using Penicillin-binding protein 2a (PbP2a) biomarker. Diamino naphthalene-AuNPs decorated graphene (AuNPsGO-DN) nanocomposite was synthesized for a rapid and sensitive immunosensor detecting PbP2a. The synthesized AuNPsGO-DN nanocomposites were characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and X-ray diffraction spectroscopy (XRD). Electrochemical characterization done with cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrical impedance spectroscopy (EIS) techniques. Anti-PbP2a monoclonal antibodies immobilized at AuNPsGO-DN/GCE via covalent bonding. AuNPs enhanced the electrode surface area and the antibodies' loading. Mercaptopropionic acid (MPA) was a linker between the AuNPs and antibodies, orientated the antibodies as opposite to the PbP2a antigen, and improved the sensitivity and specificity. The antiPbP2a/MPA/AuNPsGO-DN/GCE electrode displayed sensitive and selective detection towards the PbP2a antigen in phosphate buffer saline (PBS pH 7.4). The broad linear range from 0.01 to 8000 pg/mL was obtained with LOD of 0.154 pg/mL and 0.0239 pg/mL, respectively. A label-free, simple, and sensitive immunosensor was developed with a 98-106 % recovery rate in spiked biological samples. It shows the potential applicability of the developed immunoelectrode.

Remodeling of the Intra-Conduit Inflammatory Microenvironment to Improve Peripheral Nerve Regeneration with a Neuromechanical Matching Protein-Based Conduit

Peripheral nerve injury (PNI) remains a challenging area in regenerative medicine. Nerve guide conduit (NGC) transplantation is a common treatment for PNI, but the prognosis of NGC treatment is unsatisfactory due to 1) neuromechanical unmatching and 2) the intra-conduit inflammatory microenvironment (IME) resulting from Schwann cell pyroptosis and inflammatory-polarized macrophages. A neuromechanically matched NGC composed of regenerated silk fibroin (RSF) loaded with poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (P:P) and dimethyl fumarate (DMF) are designed, which exhibits a matched elastic modulus (25.1 ± 3.5 MPa) for the peripheral nerve and the highest 80% elongation at break, better than most protein-based conduits. Moreover, the NGC can gradually regulate the intra-conduit IME by releasing DMF and monitoring sciatic nerve movements via piezoresistive sensing. The combination of NGC and electrical stimulation modulates the IME to support PNI regeneration by synergistically inhibiting Schwann cell pyroptosis and reducing inflammatory factor release, shifting macrophage polarization from the inflammatory M1 phenotype to the tissue regenerative M2 phenotype and resulting in functional recovery of neurons. In a rat sciatic nerve crush model, NGC promoted remyelination and functional and structural regeneration. Generally, the DMF/RSF/P:P conduit provides a new potential therapeutic approach to promote nerve repair in future clinical treatments.

The role of artificial intelligence in generating original scientific research

Artificial intelligence (AI) is a revolutionary technology that is finding wide application across numerous sectors. Large language models (LLMs) are an emerging subset technology of AI and have been developed to communicate using human languages. At their core, LLMs are trained with vast amounts of information extracted from the internet, including text and images. Their ability to create human-like, expert text in almost any subject means they are increasingly being used as an aid to presentation, particularly in scientific writing. However, we wondered whether LLMs could go further, generating original scientific research and preparing the results for publication. We taskedGPT-4, an LLM, to write an original pharmaceutics manuscript, on a topic that is itself novel. It was able to conceive a research hypothesis, define an experimental protocol, produce photo-realistic images of 3D printed tablets, generate believable analytical data from a range of instruments and write a convincing publication-ready manuscript with evidence of critical interpretation. The model achieved all this is less than 1 h. Moreover, the generated data were multi-modal in nature, including thermal analyses, vibrational spectroscopy and dissolution testing, demonstrating multi-disciplinary expertise in the LLM. One area in which the model failed, however, was in referencing to the literature. Since the generated experimental results appeared believable though, we suggest that LLMs could certainly play a role in scientific research but with human input, interpretation and data validation. We discuss the potential benefits and current bottlenecks for realising this ambition here.

An Overview of Biopolymers for Drug Delivery Applications

Nowadays, drug delivery has an important role in medical therapy. The use of biopolymers in developing drug delivery systems (DDSs) is increasingly attracting attention due to their remarkable and numerous advantages, in contrast to conventional polymers. Biopolymers have many advantages (biodegradability, biocompatibility, renewability, affordability, and availability), which are extremely important for developing materials with applications in the biomedical field. Additionally, biopolymers are appropriate when they improve functioning and have a number of positive effects on human life. Therefore, this review presents the most used biopolymers for biomedical applications, especially in drug delivery. In addition, by combining different biopolymers DDSs with tailored functional properties (e.g., physical properties, biodegradability) can be developed. This review summarizes and provides data on the progress of research on biopolymers (chitosan, alginate, starch, cellulose, albumin, silk fibroin, collagen, and gelatin) used in DDSs, their preparation, and mechanism of action.

Recent Advances in Electrochemical Biosensors Targeting Stress Markers

INTRODUCTION

When the body experiences a change in its internal environment due to factors such as mood (euphoria, stress) and illness, it releases biomarkers in large quantities. These biomarkers are used for detecting a disease at its early stages. This involves the detection of insufficient quantities of biocomponents, which can be done by using nanomaterials, conventional materials, and biotechnology; thus, scientists can increase the sensitivity of electrochemical sensors. According to studies conducted in this area, electrochemical sensors have shown promise as a diagnostic tool due to their ability to identify and pinpoint illness biomarkers. The present review article was compiled to gather the latest information on electrochemical biosensors targeting stress markers.

MATERIALS AND METHODS

The authors searched scholarly databases like ScienceDirect, Pubmed, Medline, and Scopus for information on electrochemical biosensors targeting stress markers.

RESULTS

In this article, we looked at the recent developments in electrochemical sensors for stress monitoring. Because of advances in nanomaterial and biomolecule processes, electrochemical biosensors have been developed with the sensitivity to detect several biomarkers in real-time in therapeutically relevant materials.

CONCLUSION

This biomarker sensor strategy can analyze various biofluids (sweat, plasma, urine, and saliva).

Hybrid Deep Learning Techniques for Securing Bioluminescent Interfaces in Internet of Bio Nano Things

The Internet of bio-nano things (IoBNT) is an emerging paradigm employing nanoscale (~1-100 nm) biological transceivers to collect in vivo signaling information from the human body and communicate it to healthcare providers over the Internet. Bio-nano-things (BNT) offer external actuation of in-body molecular communication (MC) for targeted drug delivery to otherwise inaccessible parts of the human tissue. BNTs are inter-connected using chemical diffusion channels, forming an in vivo bio-nano network, connected to an external ex vivo environment such as the Internet using bio-cyber interfaces. Bio-luminescent bio-cyber interfacing (BBI) has proven to be promising in realizing IoBNT systems due to their non-obtrusive and low-cost implementation. BBI security, however, is a key concern during practical implementation since Internet connectivity exposes the interfaces to external threat vectors, and accurate classification of anomalous BBI traffic patterns is required to offer mitigation. However, parameter complexity and underlying intricate correlations among BBI traffic characteristics limit the use of existing machine-learning (ML) based anomaly detection methods typically requiring hand-crafted feature designing. To this end, the present work investigates the employment of deep learning (DL) algorithms allowing dynamic and scalable feature engineering to discriminate between normal and anomalous BBI traffic. During extensive validation using singular and multi-dimensional models on the generated dataset, our hybrid convolutional and recurrent ensemble (CNN + LSTM) reported an accuracy of approximately ~93.51% over other deep and shallow structures. Furthermore, employing a hybrid DL network allowed automated extraction of normal as well as temporal features in BBI data, eliminating manual selection and crafting of input features for accurate prediction. Finally, we recommend deployment primitives of the extracted optimal classifier in conventional intrusion detection systems as well as evolving non-Von Neumann architectures for real-time anomaly detection.

Black Phosphorus-Based Conductive Hydrogels Assisted by Electrical Stimulus for Skin Tissue Engineering

Conductive hydrogels have shown great potential in wound healing and skin tissue engineering, owing to their electroactive, mechanical, and chemical properties. However, it still remains as a challenge to incorporate other functions into conductive hydrogels, such as antibacterial ability, controllable drug release, and biodegradability. In this study, a black phosphorus-based conductive hydrogel (HA-DA@BP) is prepared by an amidation reaction coupled with a coordination of Fe3+ -catechol. The hydrogel could be changed from the sol phase to the gel phase under electrical stimulus (ES). The results show that BP could be released under slight acidity, which is cell compatible but could achieve synergistic electrical antibacterial action and promote wound healing. This study proves that BP is a strong candidate for electroactive materials and provides a new insight for the development of BP-based biomedical materials in skin tissue engineering.

A Review on Electroactive Polymer-Metal Composites: Development and Applications for Tissue Regeneration

Electroactive polymer-metal composites (EAPMCs) have gained significant attention in tissue engineering owing to their exceptional mechanical and electrical properties. EAPMCs develop by combining an electroactive polymer matrix and a conductive metal. The design considerations include choosing an appropriate metal that provides mechanical strength and electrical conductivity and selecting an electroactive polymer that displays biocompatibility and electrical responsiveness. Interface engineering and surface modification techniques are also crucial for enhancing the adhesion and biocompatibility of composites. The potential of EAPMC-based tissue engineering revolves around its ability to promote cellular responses, such as cell adhesion, proliferation, and differentiation, through electrical stimulation. The electrical properties of these composites can be used to mimic natural electrical signals within tissues and organs, thereby aiding tissue regeneration. Furthermore, the mechanical characteristics of the metallic components provide structural reinforcement and can be modified to align with the distinct demands of various tissues. EAPMCs have extraordinary potential as regenerative biomaterials owing to their ability to promote beneficial effects in numerous electrically responsive cells. This study emphasizes the characteristics and applications of EAPMCs in tissue engineering.

Electrospun polyvinyl alcohol-chitosan dressing stimulates infected diabetic wound healing with combined reactive oxygen species scavenging and antibacterial abilities

Diabetic wounds (DW) are constantly challenged by excessive reactive oxygen species (ROS) accumulation and susceptibility to bacterial contamination. Therefore, the elimination of ROS in the immediate vicinity and the eradication of local bacteria are critical to stimulating the efficient healing of diabetic wounds. In the current study, we encapsulated mupirocin (MP) and cerium oxide nanoparticles (CeNPs) into a polyvinyl alcohol/chitosan (PVA/CS) polymer, and then a PVA/chitosan nanofiber membrane wound dressing was fabricated using electrostatic spinning, which is a simple and efficient method for fabricating membrane materials. The PVA/chitosan nanofiber dressing provided a controlled release of MP, which produced rapid and long-lasting bactericidal activity against both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. Simultaneously, the CeNPs embedded in the membrane exhibited the desired ROS scavenging capacity to maintain the local ROS at a normal physiological level. Moreover, the biocompatibility of the multifunctional dressing was evaluated both in vitro and in vivo. Taken together, PVA-CS-CeNPs-MP integrated the desirable features of a wound dressing, including rapid and broad-spectrum antimicrobial and ROS scavenging activities, easy application, and good biocompatibility. The results validated the effectiveness of our PVA/chitosan nanofiber dressing, highlighting its promising translational potential in the treatment of diabetic wounds.

Introducing Nanoscale Electrochemistry in Small-Molecule Detection for Tackling Existing Limitations of Affinity-Based Label-Free Biosensing Applications

Electrochemical sensing techniques for small molecules have progressed in many applications, including disease diagnosis and prevention as well as monitoring of health conditions. However, affinity-based detection for low-abundance small molecules is still challenging due to the imbalance in target-to-receptor size ratio as well as the lack of a highly sensitive signal transducing method. Herein, we introduced nanoscale electrochemistry in affinity-based small molecule detection by measuring the change of quantum electrochemical properties with a nanoscale artificial receptor upon binding. We prepared a nanoscale molecularly imprinted composite polymer (MICP) for cortisol by electrochemically copolymerizing β-cyclodextrin and redox-active methylene blue to offer a high target-to-receptor size ratio, thus realizing "bind-and-read" detection of cortisol as a representative target small molecule, along with extremely high sensitivity. Using the quantum conductance measurement, the present MICP-based sensor can detect cortisol from 1.00 × 10-12 to 1.00 × 10-6 M with a detection limit of 3.93 × 10-13 M (S/N = 3), which is much lower than those obtained with other electrochemical methods. Moreover, the present MICP-based cortisol sensor exhibited reversible cortisol sensing capability through a simple electrochemical regeneration process without cumbersome steps of washing and solution change, which enables "continuous detection". In situ detection of cortisol in human saliva following circadian rhythm was carried out with the present MICP-based cortisol sensor, and the results were validated with the LC-MS/MS method. Consequently, this present cortisol sensor based on nanoscale MICP and quantum electrochemistry overcomes the limitations of affinity-based biosensors, opening up new possibilities for sensor applications in point-of-care and wearable healthcare devices.

Superior possibilities and upcoming horizons for nanoscience in COVID-19: noteworthy approach for effective diagnostics and management of SARS-CoV-2 outbreak

The outbreak of COVID-19 has caused great havoc and affected many parts of the world. It has imposed a great challenge to the medical and health fraternity with its ability to continue mutating and increasing the transmission rate. Some challenges include the availability of current knowledge of active drugs against the virus, mode of delivery of the medicaments, its diagnosis, which are relatively limited and do not suffice for further prognosis. One recently developed drug delivery system called nanoparticles is currently being utilized in combating COVID-19. This article highlights the existing methods for diagnosis of COVID-19 such as computed tomography scan, reverse transcription-polymerase chain reaction, nucleic acid sequencing, immunoassay, point-of-care test, detection from breath, nanotechnology-based bio-sensors, viral antigen detection, microfluidic device, magnetic nanosensor, magnetic resonance platform and internet-of-things biosensors. The latest detection strategy based on nanotechnology, biosensor, is said to produce satisfactory results in recognizing SARS-CoV-2 virus. It also highlights the successes in the research and development of COVID-19 treatments and vaccines that are already in use. In addition, there are a number of nanovaccines and nanomedicines currently in clinical trials that have the potential to target COVID-19.

An integrated perspective for the diagnosis and therapy of neurodevelopmental disorders - From an engineering point of view

Neurodevelopmental disorders (NDDs) are complex conditions with largely unknown pathophysiology. While many NDD symptoms are familiar, the cause of these disorders remains unclear and may involve a combination of genetic, biological, psychosocial, and environmental risk factors. Current diagnosis relies heavily on behaviorally defined criteria, which may be biased by the clinical team's professional and cultural expectations, thus a push for new biological-based biomarkers for NDDs diagnosis is underway. Emerging new research technologies offer an unprecedented view into the electrical, chemical, and physiological activity in the brain and with further development in humans may provide clinically relevant diagnoses. These could also be extended to new treatment options, which can start to address the underlying physiological issues. When combined with current speech, language, occupational therapy, and pharmacological treatment these could greatly improve patient outcomes. The current review will discuss the latest technologies that are being used or may be used for NDDs diagnosis and treatment. The aim is to provide an inspiring and forward-looking view for future research in the field.

A road map on synthetic strategies and applications of biodegradable polymers

Biodegradable polymers have emerged as fascinating materials due to their non-toxicity, environmentally benign nature and good mechanical strength. The toxic effects of non-biodegradable plastics paved way for the development of sustainable and biodegradable polymers. The engineering of biodegradable polymers employing various strategies like radical ring opening polymerization, enzymatic ring opening polymerization, anionic ring opening polymerization, photo-initiated radical polymerization, chemoenzymatic method, enzymatic polymerization, ring opening polymerization and coordinative ring opening polymerization have been discussed in this review. The application of biodegradable polymeric nanoparticles in the biomedical field and cosmetic industry is considered to be an emerging field of interest. However, this review mainly highlights the applications of selected biodegradable polymers like polylactic acid, poly(ε-caprolactone), polyethylene glycol, polyhydroxyalkanoates, poly(lactide-co-glycolide) and polytrimethyl carbonate in various fields like agriculture, biomedical, biosensing, food packaging, automobiles, wastewater treatment, textile and hygiene, cosmetics and electronic devices.

Electronically powered drug delivery devices: considerations and challenges

INTRODUCTION

Electronically powered drug delivery devices enable a controlled drug release route for a more convenient and painless way with reduced side effects. The current advances in microfabrication and microelectronics have facilitated miniaturization and intelligence with the integration of sensors and wireless communication modules. These devices have become an essential component of commercialized on-demand drug delivery.

AREAS COVERED

This review aims to provide a concise overview of current progress in electronically powered drug devices, focusing on delivery strategies, manufacturing techniques, and control circuit design with specific examples.

EXPERT OPINION

The application of electronically powered drug delivery systems is now considered a feasible therapeutic approach with improved drug release efficiency and increased patient comfort. It is anticipated that these technologies will gradually fulfill clinical needs and resolve commercialization challenges in the future. This review discusses the current advances in electronic drug delivery devices, especially focusing on designing strategies to achieve an effective drug release, as well as the perspectives and challenges for future applications in clinical therapy.

Multiplying the Stable Electrostatic Field of Electret Based on the Heterocharge-Synergy and Superposition Effect

Owing to magic charge storage behavior, an electret can exhibit an external electrostatic field, which is widely used in numerous domains such as electronics, energy, healthcare, and environment. However, the theory of the charge storage mechanism still needs further development to enhance the performance and stability of the electret. Herein, a stable charge storage model known as the heterocharge-synergy model (HSM) in electrets is proposed and verified, and the electrostatic field superposition effect of electrets is also proved. Based on the HSM and superposition effect, the stable electrostatic field intensity (average of ≈22.49 kV cm^-1 and maximum of ≈29.58 kV cm^-1 , which is close to the minimum air breakdown field intensity of ≈30 kV cm^-1 ) of the composite electret film is multiplied by simple layer-by-layer stacking. Utilizing the multilayer composite electret films and designing a two-sided electrostatic induction structure, a two-sided bipolar single-electrode non-contact nanogenerator is constructed with transferred charge density up to ≈132.61 µC m^-2 , which is twice as large as that of the non-contact nanogenerators with one-sided electrostatic induction structure. Clearing and utilizing the charge behaviors of the electret can boost the performance and enhance the stability of electret-based devices in various domains.

Biosensor-Integrated Drug Delivery Systems as New Materials for Biomedical Applications

Biosensor-integrated drug delivery systems are innovative devices in the health area, enabling continuous monitoring and drug administration. The use of smart polymer, bioMEMS, and electrochemical sensors have been extensively studied for these systems, especially for chronic diseases such as diabetes mellitus, cancer and cardiovascular diseases as well as advances in regenerative medicine. Basically, the technology involves sensors designed for the continuous analysis of biological molecules followed by drug release in response to specific signals. The advantages include high sensitivity and fast drug release. In this work, the main advances of biosensor-integrated drug delivery systems as new biomedical materials to improve the patients’ quality of life with chronic diseases are discussed.

Electroactive Polymer-Based Composites for Artificial Muscle-like Actuators: A Review

Unlike traditional actuators, such as piezoelectric ceramic or metallic actuators, polymer actuators are currently attracting more interest in biomedicine due to their unique properties, such as light weight, easy processing, biodegradability, fast response, large active strains, and good mechanical properties. They can be actuated under external stimuli, such as chemical (pH changes), electric, humidity, light, temperature, and magnetic field. Electroactive polymers (EAPs), called ‘artificial muscles’, can be activated by an electric stimulus, and fixed into a temporary shape. Restoring their permanent shape after the release of an electrical field, electroactive polymer is considered the most attractive actuator type because of its high suitability for prosthetics and soft robotics applications. However, robust control, modeling non-linear behavior, and scalable fabrication are considered the most critical challenges for applying the soft robotic systems in real conditions. Researchers from around the world investigate the scientific and engineering foundations of polymer actuators, especially the principles of their work, for the purpose of a better control of their capability and durability. The activation method of actuators and the realization of required mechanical properties are the main restrictions on using actuators in real applications. The latest highlights, operating principles, perspectives, and challenges of electroactive materials (EAPs) such as dielectric EAPs, ferroelectric polymers, electrostrictive graft elastomers, liquid crystal elastomers, ionic gels, and ionic polymer–metal composites are reviewed in this article.

Controlled Bioactive Delivery Using Degradable Electroactive Polymers

Biomaterials capable of precisely controlling the delivery of agrochemicals/biologics/drugs/fragrances have significant markets in the agriscience/healthcare industries. Here, we report the development of degradable electroactive polymers and their application for the controlled delivery of a clinically relevant drug (the anti-inflammatory dexamethasone phosphate, DMP). Electroactive copolymers composed of blocks of polycaprolactone (PCL) and naturally occurring electroactive pyrrole oligomers (e.g., bilirubin, biliverdin, and hemin) were prepared and solution-processed to produce films (optionally doped with DMP). A combination of in silico/in vitro/in vivo studies demonstrated the cytocompatibility of the polymers. The release of DMP in response to the application of an electrical stimulus was observed to be enhanced by ca. 10–30% relative to the passive release from nonstimulated samples in vitro. Such stimuli-responsive biomaterials have the potential for integration devices capable of delivering a variety of molecules for technical/medical applications.

Conductive Materials with Elaborate Micro/Nanostructures for Bioelectronics

Bioelectronics, an emerging field with the mutual penetration of biological systems and electronic sciences, allows the quantitative analysis of complicated biosignals together with the dynamic regulation of fateful biological functions. In this area, the development of conductive materials with elaborate micro/nanostructures has been of great significance to the improvement of high-performance bioelectronic devices. Thus, here, a comprehensive and up-to-date summary of relevant research studies on the fabrication and properties of conductive materials with micro/nanostructures and their promising applications and future opportunities in bioelectronic applications is presented. In addition, a critical analysis of the current opportunities and challenges regarding the future developments of conductive materials with elaborate micro/nanostructures for bioelectronic applications is also presented.

Making waves: how ultrasound-targeted drug delivery is changing pharmaceutical approaches

Administration of drugs through oral and intravenous routes is a mainstay of modern medicine, but this approach suffers from limitations associated with off-target side effects and narrow therapeutic windows. It is often apparent that a controlled delivery of drugs, either localized to a specific site or during a specific time, can increase efficacy and bypass problems with systemic toxicity and insufficient local availability. To overcome some of these issues, local delivery systems have been devised, but most are still restricted in terms of elution kinetics, duration, and temporal control. Ultrasound-targeted drug delivery offers a powerful approach to increase delivery, therapeutic efficacy, and temporal release of drugs ranging from chemotherapeutics to antibiotics. The use of ultrasound can focus on increasing tissue sensitivity to the drug or actually be a critical component of the drug delivery. The high spatial and temporal resolution of ultrasound enables precise location, targeting, and timing of drug delivery and tissue sensitization. Thus, this noninvasive, non-ionizing, and relatively inexpensive modality makes the implementation of ultrasound-mediated drug delivery a powerful method that can be readily translated into the clinical arena. This review covers key concepts and areas applied in the design of different ultrasound-mediated drug delivery systems across a variety of clinical applications.

Current Progress of Interfacing Organic Semiconducting Materials with Bacteria

Microbial bioelectronics require interfacing microorganisms with electrodes. The resulting abiotic/biotic platforms provide the basis of a range of technologies, including energy conversion and diagnostic assays. Organic semiconductors (OSCs) provide a unique strategy to modulate the interfaces between microbial systems and external electrodes, thereby improving the performance of these incipient technologies. In this review, we explore recent progress in the field on how OSCs, and related materials capable of charge transport, are being used within the context of microbial systems, and more specifically bacteria. We begin by examining the electrochemical communication modes in bacteria and the biological basis for charge transport. Different types of synthetic organic materials that have been designed and synthesized for interfacing and interrogating bacteria are discussed next, followed by the most commonly used characterization techniques for evaluating transport in microbial, synthetic, and hybrid systems. A range of applications is subsequently examined, including biological sensors and energy conversion systems. The review concludes by summarizing what has been accomplished so far and suggests future design approaches for OSC bioelectronics materials and technologies that hybridize characteristic properties of microbial and OSC systems.

Innovative technique for patterning Nd-Fe-B arrays and development of a microfluidic device with high trapping efficiency

Trapping/separating bio-entities via magnetic field gradients created a vast number of possibilities to develop biosensors for the early detection of diseases without the need for expensive equipment or physician/lab technicians. Thus, opening a window for at-home disposable rapid test kits. In the scope of the current work, an innovative and cost-effective technique to form well-organized arrays of Nd-Fe-B patterns was successfully developed. High aspect ratio Nd-Fe-B flakes were synthesized by surfactant-assisted ball milling technique. Nd-Fe-B flakes were distributed and patterned into a PDMS matrix by the aforementioned technique. A microfluidic channel was integrated on the fabricated Nd-Fe-B/PDMS patch with a high magnetic field gradient to form a microfluidic device. Fe nanoparticles, suspended in hexane, were flowed through the microfluidic channel, and trapping of the magnetic nanoparticles was observed. More experiments would be needed to quantitatively study efficiency. Ergo, the microfluidic device with high trapping efficiency was developed. The established technique has the potential to outperform the precedents in trapping efficiency, cost, and ease of production. The developed device could be integrated into disposable test kits for the early detection of various diseases.

Electroactive Polymers Obtained by Conventional and Non-Conventional Technologies

Electroactive polymers (EAPs), materials that present size/shape alteration in response to an electrical stimulus, are currently being explored regarding advanced smart devices, namely robotics, valves, soft actuators, artificial muscles, and electromechanical sensors. They are generally prepared through conventional techniques (e.g., solvent casting and free-radical polymerization). However, non-conventional processes such as those included in additive manufacturing (AM) are emerging as a novel approach to tune and enhance the electromechanical properties of EAPs to expand the scope of areas for this class of electro-responsive material. This review aims to summarize the published work (from the last five years) in developing EAPs either by conventional or non-conventional polymer processing approaches. The technology behind each processing technique is discussed as well as the main mechanism behind the electromechanical response. The most common polymer-based materials used in the design of current EAPs are reviewed. Therefore, the main conclusions and future trends regarding EAPs obtained by conventional and non-conventional technologies are also given.

Structural crystallisation of crosslinked 3D PEDOT:PSS anisotropic porous biomaterials to generate highly conductive platforms for tissue engineering applications

An emerging class of materials finding applications in biomaterials science - conductive polymers (CPs) - enables the achievement of smarter electrode coatings, piezoresistive components within biosensors, and scaffolds for tissue engineering. Despite their advances in recent years, there exist still some challenges which have yet to be addressed, such as long-term stability under physiological conditions, adequate long-term conductivity and optimal biocompatibility. Additionally, another hurdle to the use of these materials is their adaptation towards three-dimensional (3D) scaffolds, a feature that is usually achieved by virtue of applying CPs as a functionalised coating on a bulk material. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is by far one of the most promising CPs in terms of its stability and conductivity, with the latter capable of being enhanced via a crystallisation treatment using sulphuric acid. In this work, we present a new generation of 3D electroconductive porous biomaterial scaffolds based on PEDOT:PSS crosslinked via glycidoxypropyltrimethoxysilane (GOPS) and subjected to sulphuric acid crystallisation. The resultant isotropic and anisotropic crystallised porous scaffolds exhibited, on an average, a 1000-fold increase in conductivity when compared with the untreated scaffolds. Moreover, we also document a precise control over the pore microarchitecture, size and anisotropy with high repeatability to achieve both isotropic and aligned scaffolds with mechanical and electrical anisotropy, while exhibiting adequate biocompatibility. These findings herald a new approach towards generating anisotropic porous biomaterial scaffolds with superior conductivity through a safe and scalable post-treatment.

PEDOT:PSS-Based Bioelectronic Devices for Recording and Modulation of Electrophysiological and Biochemical Cell Signals

To understand the physiology and pathology of electrogenic cells and the corresponding tissue in their full complexity, the quantitative investigation of the transmission of ions as well as the release of chemical signals is important. Organic (semi-) conducting materials and in particular organic electrochemical transistor are gaining in importance for the investigation of electrophysiological and recently biochemical signals due to their synthetic nature and thus chemical diversity and modifiability, their biocompatible and compliant properties, as well as their mixed electronic and ionic conductivity featuring ion-to-electron conversion. Here, the aim is to summarize recent progress on the development of bioelectronic devices utilizing polymer polyethylenedioxythiophene: poly(styrene sulfonate) (PEDOT:PSS) to interface electronics and biological matter including microelectrode arrays, neural cuff electrodes, organic electrochemical transistors, PEDOT:PSS-based biosensors, and organic electronic ion pumps. Finally, progress in the material development is summarized for the improvement of polymer conductivity, stretchability, higher transistor transconductance, or to extend their field of application such as cation sensing or metabolite recognition. This survey of recent trends in PEDOT:PSS electrophysiological sensors highlights the potential of this multifunctional material to revolve current technology and to enable long-lasting, multichannel polymer probes for simultaneous recordings of electrophysiological and biochemical signals from electrogenic cells.