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Peptides are unique class of biomolecules for pharmaceutics and industries, given their structural features that can be applied to many approaches. Although their advantages are known, they suffer from some limitations that need to be overcome. Some disadvantages are peptidic conformations' flexibility and susceptibility to proteolytic degradation. Research has been in a constant endeavor to provide solutions. The discovery of cyclic peptides in plants opened the door for new insights into peptide‐based applications. These peptides display high stability to physical and chemical conditions. They possess a wide range of biological activities. In addition, cyclic peptides shows enhanced activities compared to linear peptides. Thus, the idea of non‐cyclic peptide cyclization can be of great use in eliminating issues and improving peptide capabilities. Inspired by the naturally found cyclic peptides, many approaches for synthetic cyclization have been proposed. The current review provides an overall discussion of the available methods for cyclization, applications, and characterization techniques. The present review offers a unique source for colleagues newly exposed to the subject and on the verge of entering the field of cyclic peptides by providing an initiating step covering the essential points needed to be considered around peptide cyclization. [ABSTRACT FROM AUTHOR]

The growing demand for personalized treatments and the constant observation of vital signs for extended periods could positively solve the problematic concerns associated with the necessity for patient control and hospitalization. The impressive development in biosensing devices has led to the creation of man-made implantable devices that are temporarily or permanently introduced into the human body, and thus, diminishing the pain and discomfort of the person. Despite all promising achievements in this field, there are some critical challenges to preserve reliable functionality in the complex environment of the human body over time. Biosensors in the in vivo environment are required to have specific features, including biocompatibility (minimal immune response or biofouling), biodegradability, reliability, high accuracy, and miniaturization (flexible, stretchable, lightweight, and ultra-thin). However, the performance of implantable biosensors is limited by body responses and insufficient power supplies (due to minimized batteries/electronics and data transmission without wires). In addition, the current processes and developments in the implantable biosensors field will open new routes in biomedicine and diagnostic systems that monitor occurrences happening inside the body in a certain period. This topical paper aims to give an overview of the state-of-the-art implantable biosensors and their design methods. It also discusses the latest developments in material science, including nanomaterials, hydrogel, hydrophilic, biomimetic, and other polymeric materials to overcome failures in implantable biosensors' reliability. Lastly, we discuss the main challenges faced and future research prospects toward the development of dependable implantable biosensors. [ABSTRACT FROM AUTHOR]

Minimally invasive approaches for cancer diagnosis are an integral step in the quest to improve cancer survival. Liquid biopsies such as blood samples are matrices explored to extract valuable information about the tumor and its state through various indicators, such as proteins, peptides, tumor DNA, or circulating tumor cells. Although these markers are scarce, making their isolation and detection in complex matrices challenging, the development in polymer chemistry producing interesting structures, including molecularly imprinted polymers, branched polymers, nanopolymer composites, and hybrids, allowed the development of enhanced platforms with impressive performance for liquid biopsies analysis. This review describes the latest advances and developments in polymer synthesis and their application for minimally invasive cancer diagnosis. The polymer structures improve the operational performances of biosensors through various processes, such as increased affinity for enhanced sensitivity, improved binding, and avoidance of non-specific interactions for enhanced specificity. Furthermore, polymer-based materials can be a tremendous help in signal amplification of usually low-concentrated targets in the sample. The pros and cons of these materials, how the synthesis process affects their performance, and the device applications for liquid biopsies diagnosis will be critically reviewed to show the essentiality of this technology in oncology and clinical biomedicine. [ABSTRACT FROM AUTHOR]

Introduction: The chronicity of advanced glycation end‐products (AGEs) imparts various damages resulting in metabolic dysfunction and diseases involving inflammation and oxidative stress. The use of plant extracts is of high interest in complementary medicine. Yet, extracts are multicomponent mixtures, and difficult to pinpoint their exact mechanism. Objectives: We hypothesise that network pharmacology and bioinformatics can help experimental findings depict the exact active components and mechanism of action by which they induce their effects. Additionally, the toxicity and variability can be lowered and standardised with proper encapsulation methods. Methodology: Here, we propose the formulation of phytoniosomes encapsulating two Artemisia species (Artemisia dracunculus and Artemisia absinthium) to mitigate AGEs and their induced cell redox dysregulation in the liver. Extracts from different solvents were identified via liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC‐Q‐TOF‐MS/MS). Phytoniosomes were explored for their anti‐glycating effect and modulation of AGE‐induced damages in THLE‐2 liver cells. Network pharmacology tools were used to identify possible targets and signalling pathways implicated. Results: Data demonstrated that A. absinthium phytoniosomes had a significant anti‐AGE effect comparable to reference molecules and higher than A. dracunculus. They were able to restore cell dysfunction through the restoration of tumour necrosis alpha (TNF‐α), interleukin 6 (IL‐6), nitric oxide, and total antioxidant capacity. Phytoniosomes were able to protect cells from apoptosis by decreasing caspase 3 activity. Network pharmacology and bioinformatic analysis confirmed the induction of the effect via Akt‐PI3K‐MAPK and AGE‐RAGE signalling pathways through quercetin and luteolin actions. Conclusion: The current report highlights the potential of Artemisia phytoniosomes as strong contenders in AGE‐related disease therapy. Two Artemisia plant extracts' applications in diabetes‐related liver diseases are studies by combining experimental and bioinformatic tools. Luteolin and quercetin as the majorcompounds induce their effect through advanced glycation end‐product (AGE)‐receptor of AGEs (RAGE) and Akt‐PI3K‐MAPK pathways according to network pharmacology analyses. Phytoniosomes are prepared in order to standardise plant‐based treatments and lower toxicity. The approach protects the liver from AGE‐induced diabetes‐related cell damages and prevents inflammatory cytokines and apoptosis regulation. [ABSTRACT FROM AUTHOR]

Diagnostic biomarkers based on epigenetic changes such as DNA methylation are promising tools for early cancer diagnosis. However, there are significant difficulties in directly and specifically detecting methylated DNA regions. Here, we report an electrochemical sensing system based on magnetic nanoparticles that enable a quantitative and selective analysis of the methylated septin9 (mSEPT9) gene, which is considered a diagnostic marker in early stage colorectal cancer (CRC). Methylation levels of SEPT9 in CRC samples were successfully followed by the selective recognition ability of a related peptide nucleic acid (PNA) after hybridization with DNA fragments in human patients' serums and plasma (n = 10). Moreover, this system was also adapted into a point-of-care (POC) device for a one-step detection platform. The detection of mSEPT9 demonstrated a limit of detection (LOD) value of 0.37% and interference-free measurement in the presence of branched-chain amino acid transaminase 1 (BCAT1) and SRY box transcription factor 21 antisense divergent transcript 1 (SOX21-AS1). The currently proposed functional platform has substantial prospects in translational applications of early CRC detection. [ABSTRACT FROM AUTHOR]

The evolution of biosensors and diagnostic devices has been thriving in its ability to provide reliable tools with simplified operation steps. These evolutions have paved the way for further advances in sensing materials, strategies, and device structures. Polymeric composite materials can be formed into nanostructures and networks of different types, including hydrogels, vesicles, dendrimers, molecularly imprinted polymers (MIP), etc. Due to their biocompatibility, flexibility, and low prices, they are promising tools for future lab-on-chip devices as both manufacturing materials and immobilization surfaces. Polymers can also allow the construction of scaffold materials and 3D structures that further elevate the sensing capabilities of traditional 2D biosensors. This review discusses the latest developments in nano-scaled materials and synthesis techniques for polymer structures and their integration into sensing applications by highlighting their various structural advantages in producing highly sensitive tools that rival bench-top instruments. The developments in material design open a new door for decentralized medicine and public protection that allows effective onsite and point-of-care diagnostics. [ABSTRACT FROM AUTHOR]

Drug abuse is an alarming subject affecting modern society. Unlike alcohol consumption control, substance abuse monitoring still lacks standardized, non-invasive, and efficient biosensors for on-site diagnostics. Most of the approaches are based on blood sampling and traditional chromatographical techniques. Here, we propose two colorimetric lateral flow immunoassays (LFIA) using Rhodamine B-loaded polymersomes for cocaine (COC) and methamphetamine (METH) detection on saliva samples. Polymersomes were synthesized from methoxy polyethylene glycol and polycaprolactone and then loaded with the dye. Furthermore, the bioconjugation of the specific antibodies on the surface was confirmed via various analytical methods. The LFIA platform was based on a competitive type that is more suitable for detecting small-sized molecules. The sensitivity of the LFIA was quantitatively measured using smartphone-assisted imaging analysis and showed a limit of detection (LOD) of 0.49 ng/mL (COC) and 0.37 ng/mL (METH). Moreover, the specificity was also investigated against various interferents. The analytical performance of the LFIA platform was tested over synthetic and real human saliva, which showed an overall accuracy of 97% and 98.4%, respectively. The LFIA offers excellent stability under various salivary conditions (pH and incubation time) and keeps steady performance when comparing spiked buffer with synthetic and human saliva. The use of non-invasive sampling such as saliva in combination with on-site sensing devices can be of great potential for future applications and implementation of portable biosensors. [ABSTRACT FROM AUTHOR]

Supply shortage for the development and production of preventive, therapeutic, and diagnosis tools during the COVID-19 pandemic is an important issue affecting the wealthy and poor nations alike. Antibodies and antigens are especially needed for the production of immunological-based testing tools such as point-of-care tests. Here, we propose a simple and quick magnetic nanoparticle (MNP)–based separation/isolation approach for the repurposing of infected human samples to produce specific antibodies and antigen cocktails. Initially, an antibody cocktail was purified from serums via precipitation and immunoaffinity chromatography. Purified antibodies were conjugated onto MNPs and used as an affinity matrix to separate antigens. The characterization process was performed by ELISA, SDS-PAGE, electrochemistry, isothermal titration calorimetry, and LC-Q-TOF-MS/MS analyses. The MNP-separated peptides can be used for mass spectrometry–based as well as paper-based lateral flow assay diagnostic. The exploitation of the current workflow for the development of efficient diagnostic tools, specific treatments, and fundamental research can significantly impact the present or eventual pandemic. This workflow can be considered as a two birds, one stone–like strategy. [ABSTRACT FROM AUTHOR]

Point‐of‐care approaches are in constant need of novel and highly performant portable devices. Doping is a constant issue seen in the athletic field, and a need for mobile and trustable methods for detection are highly sought. The current work proposes a portable biosensor based on a screen‐printed electrode (SPE) and functionalized magnetic particles for testosterone detection. The functionalized magnetic particles were characterized with SEM and the designed biosensor was analyzed amperometrically (Pulse Voltammetry (DPV), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectrometry (EIS)). Results demonstrate linearity between 50–1000 ng/mL with a LOD of 23.68 ng/mL. Q‐TOF/MS method was performed to compare with the biosensor over serum and urine. Furthermore, the selectivity of the biosensor was tested in the presence of various interferents. The designed biosensor shows good potential in doping detection and prevention of illicit use due to the versatility of application that it covers. [ABSTRACT FROM AUTHOR]

Chitosan-based materials are widely used in various industries due to their environmental friendliness (biodegradable and non-toxicity) and other antimicrobial properties. Improving the chitosan capacities using additional components such as titanium dioxide (TiO 2) and other nanoparticles proves beneficial. Here, we propose the combination of chitosan-TiO 2 nanocomposites (ChiTiO) with various metal ions (silver, zinc, copper, and iron), forming novel chitosan-based films to improve the capacities of the material further. The ChiTiO-ion metals nanocomposites and films were synthesized and characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV–Vis), Fourier transforms infrared spectroscopy (FT-IR), X-ray fluorescence (XRF), and cyclic voltammetry techniques. The biological activities of the metal-doped formulations showed increased antioxidant activities led by ChiTiO@Ag. Additionally, the methylene blue (MB) dye degradation capabilities were dominated by ChiTiO@Cu. The material showed a higher specificity towards MB than other dyes (methyl orange and bromophenol blue). The photocatalytic degradation at high temperatures (60 °C) was faster than at ambient (25 °C) and cold (4 °C) temperatures. The reusability of the film showed sustained photocatalytic capacities even after three cycles with a low loss of 16.7%. The antimicrobial activities of the films were tested against three pathogens (S. aureus , C. albicans , and P. aeruginosa) under different light conditions. Data showed ChiTiO@Ag with a concentration of 0.5 g composite having the best activity compared with the other materials. The most important finding is the ability of the proposed films to perform their activities without the need for any light activation. Lastly, ChiTiO@ion metals provide promising applications as ambient light packaging materials, coating materials, and photocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

Artificial nanostructures using polymers to produce polymeric vesicles are inspired by the many intricate structures found in living organisms. Polymersomes are a class of self-assembled vesicles known for their great stability and application in drug delivery. They can be tuned according to their intended use by changing their components and introducing activable block copolymers that transform these polymersomes into smart nanocarriers. In this study, we propose the synthesis of a poly (ethylene oxide)-poly (ε- caprolactone)-based polymersome (PEO-PCL) loaded with GSH as a pH-responsive drug delivery molecule for cancer and protein alteration inhibition. Initially, the nanocarrier was synthesized and characterized by DLS, TEM/SEM microscopy as well as gel permeation chromatography (GPC) and 1H NMR. Their CMC formation, encapsulation efficiency, and pH responsiveness were analyzed. In addition, empty and GSH-loaded PEO-PCL polymersomes were tested for their toxicity and therapeutic effect on normal and cancer cells via an MTT test. Subsequently, protein alteration models (aggregation, glycation, and oxidation) were performed in vitro where the polymersomes were tested. Results showed that other than being non-toxic and able to highly encapsulate and release the GSH in response to acidic conditions, the nanocomposites do not hinder its content's ameliorative effects on cancer cells and protein alterations. This infers that polymeric nanocarriers can be a base for future smart biomedicine applications and theranostics. Image 1 [ABSTRACT FROM AUTHOR]

The global pandemic of COVID-19 continues to be an important threat, especially with the fast transmission rate observed after the discovery of novel mutations. In this perspective, prompt diagnosis requires massive economical and human resources to mitigate the disease. The current study proposes a rational design of a colorimetric lateral flow immunoassay (LFA) based on the repurposing of human samples to produce COVID-19-specific antigens and antibodies in combination with a novel dye-loaded polymersome for naked-eye detection. A group of 121 human samples (61 serums and 60 nasal swabs) were obtained and analyzed by RT-PCR and ELISA. Pooled samples were used to purify antibodies using affinity chromatography, while antigens were purified via magnetic nanoparticles-based affinity. The purified proteins were confirmed for their specificity to COVID-19 via commercial LFA, ELISA, and electrochemical tests in addition to sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Polymersomes were prepared using methoxy polyethylene glycol- b -polycaprolactone (mPEG- b -PCL) diblock copolymers and loaded with a Coomassie Blue dye. The polymersomes were then functionalized with the purified antibodies and applied for the preparation of two types of LFA (antigen test and antibody test). Overall, the proposed diagnostic tests demonstrated 93 and 92.2% sensitivity for antigen and antibody tests, respectively. The repeatability (92-94%) and reproducibility (96-98%) of the tests highlight the potential of the proposed LFA. The LFA test was also analyzed for stability, and after 4 weeks, 91-97% correct diagnosis was observed. The current LFA platform is a valuable assay that has great economical and analytical potential for widespread applications.

Chemotherapy has seen great progress in the development of performant treatment strategies. Nanovesicles such as liposomes and polymersomes demonstrated great potential in cancer therapy. However, these nanocarriers deliver their content passively, which faces a lot of constraints during blood circulation. The main challenge resides in degradation and random delivery to normal tissues. Hence, targeting drug delivery using specific molecules (such as antibodies) grafted over the surface of these nanocarriers came as the answer to overcome many problems faced before. The advantage of using antibodies is their antigen/antibody recognition, which provides a high level of specificity to reach treatment targets. This review discusses the many techniques of nanocarrier functionalization with antibodies. The aim is to recognize the various approaches by describing their advantages and deficiencies to create the most suitable drug delivery platform. Some methods are more suitable for other applications rather than drug delivery, which can explain the low success of some proposed targeted nanocarriers. In here, a critical analysis of how every method could impact the recognition and targeting capacity of some nanocarriers (liposomes and polymersomes) is discussed to make future research more impactful and advance the field of biomedicine further.