Qurat Ul Ain Zahra

Traditional screening of aptamers for small-molecule targets is often inefficient, typically requiring more than 13 rounds of selection. To address this inefficiency, we optimized the Capture-SELEX process by refining key factors that impact selection efficacy. By extending the length of the capture sequence and reducing the self-dissociation rate to minimize background noise, we significantly enhanced the screening efficiency. Utilizing meperidine (MPD), an addictive substance, as a model, we successfully identified aptamers within just six rounds. We further validated these optimized conditions using a multitarget mixed SELEX approach and successfully obtained high-affinity aptamers. To demonstrate the practical application of these aptamers, we developed two fluorescent biosensors incorporating MPD aptamers. This biosensor achieved a detection limit of 60 nM for MPD in artificial saliva and exhibited excellent specificity even in the presence of various interfering substances. This indicates that our method is effective for both single and mixed targets. By employing a 20-base-long capture sequence to minimize library self-dissociation, we have addressed the long-standing inefficiencies of Capture-SELEX, significantly improving the screening of small-molecule aptamers. This advancement is anticipated to greatly enhance the application of aptamers in small-molecule research and on-site drug detection.

Graphene has attracted extensive attention in various fields due to its intriguing properties. In this work, nanocomposite films based on poly(lactic acid) (PLA and PLLA) polymers filled with graphene oxide (GO) were developed. The impact of treating GO with the anionic surfactant dioctyl sulfosuccinate sodium salt (AOT) on the properties of the resulting nanocomposites was investigated. To determine the morphological, optical, and structural properties of the obtained materials, physicochemical analyses were performed, including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) analysis. Additionally, the thermal properties and wettability of neat polymers and nanocomposites were thoroughly investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and contact angle analysis. It was observed that GO was well dispersed throughout the PLA and PLLA matrix, leading to stronger interface bonding. The results demonstrate that the untreated and treated GO improved the crystallinity and thermal stability properties of the PLA and PLLA. However, the AOT-treated GO has significantly higher performance compared to the untreated GO in terms of crystallinity, melting temperature (increased by ~15 °C), and wettability (the contact angle decreased by ~30°). These findings reveal the high performance of the developed novel composite, which could be applied in tissue engineering as a scaffold.

Fabricating an organic–inorganic nanocomposite hydrogel platform with antibacterial, anti-inflammatory, and osteoinductive properties that mimic bone extracellular matrix composition is decisive for guiding bone development in orthopedic practice. Despite significant progress in developing hydrogels for tissue repair, little attention has been paid to replicating the natural bone ECM microenvironments and addressing the importance of anti-inflammatory agents during osteogenesis. Herein, we developed ciprofloxacin and dexamethasone loaded strontium (Sr) and/or iron (Fe) substituted hydroxyapatite (HAp) nanomaterials precipitated in collagen (Col) to construct a multifunctional bioactive nanocomposite hydrogel platform to prevent inflammation and bacterial adhesion, leading to augmenting bone development in the defect site. The fabricated nanocomposite hydrogels (Sr:HAp-Col, Fe:HAp-Col, and Sr/Fe:HAp-Col) were physicochemically characterized and demonstrated high loading and prolonged drug release, and excellent antibacterial activity against Gram-positive and Gram-negative bacteria. In in vitro experiments, the Sr/Fe:HAp-Col sample exhibited enhanced bioactivity against the preosteoblast MC3T3-E1 cell line, with high alkaline phosphatase and bone-like inorganic calcium deposition, as well as increased gene expression of osteogenesis-related differentiation markers, including OPN, OCN, and RUNX2. Furthermore, in vivo experiments revealed that the Sr/Fe:HAp-Col matrix degraded over time by controlling the release of ions into the body, without causing acute inflammation at the implanted site or in the blood serum, or in the internal organs, including the heart, lungs, liver, and kidney of the Sprague–Dawley rat model. The micro-CT scan and histological examination showed high bone mineral density and more mature bone formation at the nanocomposite hydrogel implanted site associated with the ColMA hydrogel in the femur defect of the rat model. The strategy of applying collagen hydrogel supplemented with HAp to bone regeneration is promising due to its ability to mimic the natural bone ECM. Overall, the developed bioactive nanocomposite hydrogel may have great potential not only in bone regeneration but also in repairing nonunion-infected defects of other tissues.

The COVID-19 pandemic, caused by a new coronavirus, has affected economic and social standards as governments and healthcare regulatory agencies throughout the world expressed worry and explored harsh preventative measures to counteract the disease’s spread and intensity. Several academics and experts are primarily concerned with halting the continuous spread of the unique virus. Social separation, the closing of borders, the avoidance of big gatherings, contactless transit, and quarantine are important methods. Multiple nations employ autonomous, digital, wireless, and other promising technologies to tackle this coronary pneumonia. This research examines a number of potential technologies, including unmanned aerial vehicles (UAVs), artificial intelligence (AI), blockchain, deep learning (DL), the Internet of Things (IoT), edge computing, and virtual reality (VR), in an effort to mitigate the danger of COVID-19. Due to their ability to transport food and medical supplies to a specific location, UAVs are currently being utilized as an innovative method to combat this illness. This research intends to examine the possibilities of UAVs in the context of the COVID-19 pandemic from several angles. UAVs offer intriguing options for delivering medical supplies, spraying disinfectants, broadcasting communications, conducting surveillance, inspecting, and screening patients for infection. This article examines the use of drones in healthcare as well as the advantages and disadvantages of strict adoption. Finally, challenges, opportunities, and future work are discussed to assist in adopting drone technology to tackle COVID-19-like diseases.

Heavy metals ions as metallic pollutants are a growing global issue due to their adverse effects on the aquatic ecosystem, and human health. Unfortunately, conventional detection methods such as atomic absorption spectrometry exhibit a relatively low limit of detection and hold numerous disadvantages, and therefore, the development of an efficient method for in-situ and real-time detection of heavy metal residues is of great importance. The aptamer-based sensors offer distinct advantages over antibodies and emerged as a robust sensing platform against various heavy metals due to their high sensitivity, ease of production, simple operations, excellent specificity, better stability, low immunogenicity, and cost-effectiveness. The nucleic acid aptamers in conjugation with nanomaterials can bind to the metal ions with good specificity/selectivity and can be used for on-site monitoring of metal ion residues. This review aimed to provide background information about nanomaterials-based aptasensor, recent advancements in aptamer conjunction on nanomaterials surface, the role of nanomaterials in improving signal transduction, recent progress of nanomaterials-based aptasening procedures (from 2010 to 2022), and future perspectives toward the practical applications of nanomaterials-based aptasensors against hazardous metal ions for food safety and environmental monitoring.

Over the last decade, the superior properties of graphene have contributed to intensive studies on the fabrication and applications of graphene nanocomposites. Ex-situ homologous recombination and recombination techniques were listed. Because of their remarkable features, including thermal conductivity and high-specific area, graphene and its derivatives have a significant prospective for medical and biological applications, including drug delivery and bio-imaging. The usage of graphene-based nanomaterials is a hot topic in medicinal research. Many research studies have been performed on graphene-based composites, but only a few reviews have been published regarding their applications in the biomedical field and potential risk factors associated with human well-being and the environment. Hence, this review paper aims to provide in-depth information on ongoing knowledge and results about the properties of graphene-based composites. The discovery, developmental methods, structural properties, and synthesis of graphene nanomaterials have been discussed. After a brief description of the most common methods used for fabricating or extracting graphene derivatives, the main steps of graphene-based composite preparation are introduced. Applications of graphene-based composites in drug delivery, medical, and biomedical fields have been addressed. Finally, the future perspectives and challenges associated with the applications of graphene-based composites have been summarized. GRAPHICAL ABSTRACT