The disease of osteoporosis is characterized by impaired bone structure and an increased risk of fractures. There is a significant impact of cytokines and hormones on bone homeostasis and the diagnosis of osteoporosis. As defined by the World Health Organization (WHO), osteoporosis is defined as having a bone mineral density (BMD) that is 2.5 standard deviations (SD) or more below the average for young and healthy women (T score < −2.5 SD). Cytokines and hormones, particularly in the remodeling of bone between osteoclasts and osteoblasts, control the differentiation and activation of bone cells through cytokine networks and signaling pathways like the nuclear factor kappa-B ligand (RANKL)/the receptor of RANKL (RANK)/osteoprotegerin (OPG) axis, while estrogen, parathyroid hormones, testosterone, and calcitonin influence bone density and play significant roles in the treatment of osteoporosis. This review aims to examine the roles of cytokines and hormones in the pathophysiology of osteoporosis, evaluating current diagnostic methods, and highlighting new technologies that could help for early detection and treatment of osteoporosis.

The vulnerability of skin wounds has made efficient wound dressing a challenging issue for decades, seeking to mimic the natural microenvironment of cells to facilitate cell binding, augmentation, and metamorphosis. Many three-dimensional (3D) bioprinted hydrogel-based configurations have been developed using high-tech devices to overcome the limitations of traditional dressing materials. Based on a material perspective, this review examines current state-of-the-art 3D bioprinting for hydrogel-based dressings, including both their advantages and limitations. Accordingly, their potential applications in terms of their performance in vitro and in vivo, as well as their adaptability to clinical settings, were investigated. Moreover, different configurations of 3D bioprinters are discussed. Finally, a roadmap for advancing wound dressings fabricated with 3D bioprinting is presented.

The quartz tuning fork (QTF) is a promising instrument for biosensor applications due to its advanced properties such as high sensitivity to physical quantities, cost-effectiveness, frequency stability, and high-quality factor. Nevertheless, the fork’s small size and difficulty in modifying the prongs’ surfaces limit its wide use in experimental research. Our study presents the development of a QTF immunosensor composed of three active layers: biocompatible natural melanin nanoparticles (MNPs), glutaraldehyde (GLU), and anti-IgG layers, for the detection of immunoglobulin G (IgG). Frequency shifts of QTFs after MNP functionalization, GLU activation, and anti-IgG immobilization were measured with an Asensis QTF F-master device. Using QTF immunosensors that had been modified under optimum conditions, the performance of QTF immunosensors for IgG detection was evaluated. Accordingly, a finite element method (FEM)-based model was produced using the COMSOL Multiphysics software program (COMSOL License No. 2102058) to simulate the effect of deposited layers on the QTF resonance frequency. The experimental results, which demonstrated shifts in frequency with each layer during QTF surface functionalization, corroborated the simulation model predictions. A modelling error of 0.05% was observed for the MNP-functionalized QTF biosensor compared to experimental findings. This study validated a simulation model that demonstrates the advantages of a simulation-based approach to optimize QTF biosensors, thereby reducing the need for extensive laboratory work.

Due to their minimal invasiveness catheters are highly preferred in cardiac mapping techniques used in the source localization of rhythm disturbances in the heart. In cardiac mapping, standard steerable catheters and multielectrode basket catheters are the two alternatives for the characterization of the underlying tissue on the inner (endocardium) and outer (epicardium) surfaces of the heart. As with any discrete sampling technique, an important question for catheter-based cardiac mapping is how to determine values at locations from which direct measurements are not available. Interpolation is the most common approach for providing values at unmeasured sites using the available measurements. In this study, the usage of spline interpolation technique in catheter-based cardiac mapping was introduced for the first time in the literature and compared with the existing approaches such as the nearest-neighbor, Laplacian, and Hardy's interpolation techniques. For different sampling resolutions on the endocardium and epicardium, we reconstructed the activation-time values on unmeasured sites using measured values. To provide quantitative validation, we have applied these methods to high resolution simulated activation-time values from a realistic heart model using Aliev-Panfilov mathematical modeling approach. The results show that spline, Laplacian, and Hardy interpolation methods performed successfully and also better than nearest-neighbor method. Among all interpolation schemes except for the nearest-neighbor method the average correlation coefficient (CC) values were greater than 0.985.

Melanin nanoparticles (MNPs) have attracted growing attention in biomedical fields due to their wide bioavailability, high biocompatibility, biodegradability, and multifunctionality. Key features of MNPs are broad-spectrum light absorption, high drug-loading capacity, near-infrared light-triggered drug release and reactive oxygen species generation, efficient hepatobiliary, renal clearance, and superior binding affinity towards metal ions that enhance MNPs’ traceability in magnetic resonance imaging (MRI). Despite challenges such as agglomeration in time, lack of extraction standardization, and a limited number of animal and clinical studies, the strong photothermal conversion and reactive species production abilities of MNPs make them effective photosensitizers and photothermal agents, while their dual capability for molecular binding and metal chelation positions them as promising agents for theranostic applications. This review provides a comprehensive overview of MNPs, covering their structural features, manufacturing methods and associated limitations, and recent advances in their physicochemical characterization. Special focus is given to MRI-guided biomedical applications, including drug delivery, photothermal therapy, and photodynamic therapy, along with critical challenges related to the clinical translation and commercialization of MNP-based platforms. By consolidating recent advances, this review highlights key structure–function relationships that underpin emerging melanin-based nano-systems.