Introduction: Titanium and its alloys are extensively used in orthopaedic applications due to their excellent mechanical properties, biocompatibility, and corrosion resistance. Direct coupled electrical stimulation (DCES) has also been demonstrated to promote bone regeneration and osseointegration in clinical trials. However, titanium is not often the material of choice for electrically stimulating bioelectrodes, especially as both the cathode and anode. This is mainly due to titanium’s lower conductivity compared to other biocompatible materials, like gold and platinum, and the tendency for the passive oxide layer to transform, which although contributing to its excellent corrosion resistance can impact signal stability. Nonetheless, dual titanium bioelectrodes have made their way into several clinical applications, such as spinal fusion, but have not been extensively characterized.

Methods: This study explores the effects of anodization voltage (0, 5, and 10 V) and oxide layer configuration (single or double passivation) on electric field distribution under voltage-controlled constant DCES for commercially pure titanium electrodes. Computational modelling frameworks for estimating electric field distributions were also re-evaluated using COMSOL Multiphysics to address the ambiguous reporting standards that are hindering the widespread application of DCES in implant design.

Results: The results demonstrate that improper choice of the modelling framework can overestimate the electric field by up to an order of 4 in constant DCES systems. It was also found that the electric field only behaves uniformly near the centre of the stimulation chamber (roughly 3 mm from the centre), with much greater electric field gradients in the direction parallel to the electrodes.

Conclusion: These results suggest that the electric fields reported in previous in vitro DCES studies should be re-evaluated using appropriate computational electrochemical approaches. This reassessment will help inform the design of electrically stimulating medical devices and expedite the clinical translation of DCES for bone regenerative therapies.

In this presentation, we will present the research that has been published in the last ten years on the use of an innovative piece of technology—the knee kinesiography exam. This exam relies on a harness (the KneeKG) attached on the shank and the thigh, which reduces soft tissue artifacts compared to methods using markers glued on the skin. On the harness are fixed optoeletronic markers, whose movements are followed by a portable optoelectronic camera (NDI). The exam consists of a calibration phase, followed by two 45 second walking periods on a treadmill. The system then automatically identifies biomechanical markers on the flexion/extension, ab/adduction and internal/external rotation curves. These markers, known to be related to pain and disease progression, are then translated into patient-specific exercises to be performed at home. Several medium and large cohort studies used the knee kinesiography exam to characterize three-dimensional knee kinematics in a healthy population, in various degrees of knee osteoarthritis, in patients who underwent unicompartmental or total knee arthroplasty and in patients who experienced a ligament rupture. This presentation will summarize the main results issued from these studies, highlighting the clinical usefulness of the technology for managing knee problems.

Introduction:

Belzutifan is a hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor used for the treatment of von Hippel–Lindau disease-associated renal cell carcinoma.

Method:

A simple, accurate, precise, and specific HPLC method was developed for the estimation of Belzutifan (BZT) in human plasma using Emtricitabine (ETC) as an internal standard. The analyte and ISTD were separated on a Kromasil C18 (250x4.6mmx5µ) column using a mobile phase composition. The buffer was composed of Acetonitrile(60:40). The RTs of the analyte and ISTD were found to be 3.446 and 2.363min, respectively, at a flow rate of 1ml/min.

Results:

Further, the reported method was validated as per the USFDA guidelines, and was found to be well within the acceptable range for all parameters with concentrations of LLOQ 0.075µg/ml, LQC 0.225µg/mL,MQC 1.5µg/mL, HQC 2.4µg/mL, and ULOQ 3.0 µg/mL. The matrix effect at HQC and LQC was 100.19 and 99.83%; the sensitivity at LLOQ was 99.63%; the precision and accuracy at HQC, MQC, LQC, and LLOQ was between 98.56 and100.11%. The linearity concentration is in the range of 0.75-3µg/mL for Belzutifan with a correlation coefficient of r² = 0.999 with good stability.

Conclusion:

The proposed HPLC method was simple, rapid, precise, and accurate for the determination of Belzutifan in human plasma. Sample preparation showed high recovery and this method shows a higher sample throughput due to the short chromatography time ( 3.446 min) and simple sample preparation. Thus, the developed HPLC method can be applied to the bioequivalence and pharmacokinetic studies of Belzutifan in human plasma samples and is appropriate for therapeutic drug monitoring in clinical laboratories.

Introduction: Bacterial adhesion on medical devices can have serious consequences, somtimes leading to chronic infections if biofilm formation cannot be prevented. When bacteria colonies form in surgical sites, the bacteria contribute to prolonged inflammation, delay tissue regeneration, and jeopardize the natural healing process. The formation of biofilms is a significant health issue, as they cannot be prevented using conventional antimicrobial treatments. It has been reported in the literature that electrical stimulation (ES) may result in bacteria inhibition through molecular regulatory mechanisms. The current study explores the effect of low-level ES on Staphylococcus epidermidis (S.epidermis) and Escherichia coli (E.coli), and our results show a promising E.coli inhibition efficiency was achieved.

Methods: Petri dishes with Grade 5 cpTi rods as electrodes were fabricated with a separation distance of 3cm between electrodes. A total of 20mL of Tryptic Soy Agar was dispensed into each dish and bacteria species were grown up to the mid-log phase, before a bacterial lawn was created. Then, 30 minutes of ES was delivered at varying voltages (1V, 300mV, and 100mV) and frequencies (3MHz, 1MHz, 0.75MHz, and 0.5MHz) and samples were then incubated at 37C for 24 hours. The zone of inhibition (ZOI) around the electrodes after incubation was measured using ImageJ.

Results: All ES parameters showed various levels of inhibition against E.coli. Based on the data collected, 1V at 1MHz showed the largest ZOI with a statistical difference compared to 100mV at 1MHz and 1V at 0.5MHz. There was no inhibition of growth at any ES parameter when tested against S.epidermis.

Conclusions: The use of low-level ES against bacteria growth has major clinical applications that can help reduce post-operative infection risk and lower the risk of antibiotic resistance. The results indicate a need for further research to understand the influence of ES parameters on various bacteria. Future studies will include ES against other common bacterial species associated with infections.

The advent of 3D printing technology has revolutionized various manufacturing sectors including the medical field, particularly in the production of prosthetic limbs. Traditional prosthetic manufacturing processes are often time-consuming and expensive, causing amputees to endure long waiting periods and high costs. In contrast, 3D printing offers a rapid, cost-effective alternative, enabling the creation of custom-made prosthetics tailored to the specific needs and measurements of each wearer. Integrating 3D printing technology into prosthetics and orthopedics has ushered in a new era of customization and innovation. This advanced approach facilitates the creation of personalized prosthetics and bone replacements tailored to individual patients' needs. With the latest advancements in software and 3D printing, the use of custom orthopedic implants for complex surgical cases has gained significant popularity. This paper explores the advantages of using 3D printing for prosthetic limb production, highlighting its ability to significantly reduce production time and costs while maintaining high functionality and quality. By leveraging 3D scanning and computer-aided design (CAD), precise digital models of a patient's residual limb can be created, ensuring a perfect fit and improved comfort. Additionally, the flexibility of 3D printing allows for the incorporation of advanced materials and design features, enhancing the durability and performance of the prosthetics. This study also examines the potential for 3D printing to democratize access to prosthetic care, especially in low-resource settings. The affordability and accessibility of 3D printers, coupled with open-source designs, empower local communities and healthcare providers to produce prosthetics on demand, reducing dependency on centralized manufacturing facilities. By addressing the current limitations and challenges, including material constraints and regulatory hurdles, this paper highlights the transformative impact of 3D printing on the prosthetics industry.

Abstract Title:
Enhancing burn wound healing with Plectranthus amboinicus extract-loaded foam dressings

Introduction: Foam dressings have been effective in treating pressure injuries/ulcers, diabetic foot ulcers, and venous ulcers, among other chronic wounds. Even though the currently available polyurethane foams are absorbent in nature, there is a need for the development of foams which are highly hydrophilic in nature. Plectranthus amboinicus is traditionally used as an anti-inflammatory and wound-healing agent. Its incorporation in a hydrophilic polyurethane (PU)-based foam dressing will offer the dual benefits of a highly absorbent foam dressing and the healing potential of P. amboinicus.

Methods: Hydrophillic PU foam dressings were prepared and loaded with P. ambionicus leaf extract (PAE). The dressings were prepared with varying concentrations of extract along with Toluene diisocyanate, polyols, catalysts, chain extenders, and hydrophilic polymers. The microstructure, moisture vapour transmission rate, porosity, absorption rate, surface roughness, and mechanical strength of the dressings was assessed followed by in vivo dermal irritation studies on rabbits and burn wound healing studies in a rodent model.

Results and Discussion: The moisture vapour transmission rate of the dressings was found to range between 1900.06 ±0.59 and 2050.00 ± 0.25 g/m²/day. The absorption rate was found to be between 1.27 ± 0.01 and 1.31 ± 0.00 g/cm² and was found to be highest with dressings containing polyacrylate as hydrophilic polymer. Tensile strength measurement indicated that the selected formulations were flexible enough to withstand regular handling during dressing changes. Acute dermal irritation performed on rabbits showed no irritation, erythema, eschar, oroedema. The in vivo burn wound healing studies performed on albino Wistar rats showed better healing in comparison to a commercial formulation.

Conclusions: The hydrophilic foam dressing developed using Plectranthus amboinicus leaf extract demonstrated promising efficacy in burn wound healing, suggesting its potential as an effective natural remedy for burn wound management.

The principles of “green chemistry” establish the definite demands for chemical procedures in carrying out synthetic or analytic methods using compounds extracted from biological resources. Thus, nanoparticle synthesis based on components extracted from bacteria, fungi, algae and plantae has been used for wide applications. Natural proteins, lipids, carbohydrates and unsaturated aliphatic (aromatic) compounds have the capability to act as reducing and stabilizing agents in nanoparticle synthesis. Gold nanoparticles (GNPs) have been known to be characterized by some specific features, viz. plasmonic ones, which are the main factors in the exposure of SPR, LPR and SERS. The formation of a limited area in isotropic and homogeneous media is a necessary condition for the appearance of a new phase (nanoreactor formation), which is the result of kinetic (diffusion) and spatial effects (thepresence of both structural and electrostatic obstacles). Taken together, these lead to some peculiarities in the region where nanostructure growth occurs. A nanoreactor can be viewed as a nanobot, defined as “a controllable nanoscale machine composed of a sensor and motor used to perform specific tasks specified by the appropriate conditions”. The specific task is GNP formation, the sensor is the environment condition (temperature and pH) and the motor (driven forces) is the specific medium conformation where the GNPs are formed. In order to recognize a nanobot's features, we determine the factors (environment content, its temperature and pH) influencing its capability to form GNPs. Such recognition is facilitated by the data obtained from TEM, SPR and SERS on the formed GNPs. The main aim of our investigation is to provide the method for nanobot feature recognition using a model of a multilayer fully connected perceptron whose architecture includes several hidden layers with different numbers of neurons to ensure the depth of the learning and the ability to process the complex dependencies in the data.

Bloodstream infections (BSIs) pose a significant threat to public health, particularly in developing countries with limited diagnostic facilities. Increased levels of carbon dioxide (CO₂) in blood samples indicate the presence of microorganisms, making CO₂ monitoring crucial for the early detection of blood infections like sepsis. Traditional blood culture methods are often expensive, time-consuming, and prone to contamination. The lack of cost-effective and efficient diagnostic tools hampers timely and accurate diagnosis, leading to delayed treatments and higher mortality rates. This study, therefore, addresses this critical gap by developing a semi-automated blood culture CO₂ monitoring device that is low-cost, efficient, and suitable for Low- or Middle-Income Countries (LMICs).

The semi-automated CO₂ monitoring device (SCMD) was developed using an MQ-2 gas sensor, powered by a 9V battery and a 5V regulator for the ATmega microcontroller. The device was tested with three positive and two negative sepsis samples in the University College Hospital (UCH) microbiology laboratory. Its performance was compared with traditional blood culture techniques, which are the gold standard, and the BACTEC blood culture bottle. The accuracy of the device and the testing time were evaluated.

The SCMD detected the increased CO₂ produced by the growth of microorganisms in infected blood samples with over 90% accuracy and substantially reduced the turnaround times for detecting bacterial growth, potentially enabling quicker diagnosis and treatment of sepsis, by displaying test results in less than five minutes. Additionally, the device demonstrated a running time of up to 24 hours on a single battery charge, making it suitable for continuous use in healthcare settings.

The semi-automated CO₂ monitoring device offers a prompt solution to improve diagnostic capabilities and patient outcomes in resource-constrained environments. Integrating this device into existing healthcare infrastructure could significantly enhance the timely detection and treatment of bloodstream infections, ultimately saving lives.

Introduction. Polyethylenimine (PEI) is one of the most studied molecules for non-viral delivery of nucleic acids into cells. The widespread use of PEI is limited because of instability of its polyplexes in the presence of serum components, as well as toxic effects. Modification of PEI polyplexes with charge-shielding coating will overcome the limitations of transfection in the presence of serum components. We developed anionic peptide coating modified with ανβ3 integrin ligand for targeted delivery. The purpose of this work was to study DNA/PEI polyplexes with anionic peptide coating as a means of delivering DNA into cells.

Methods. Glutamate-rich peptides modified with cycloRGD ligand were synthesized. Physicochemical properties of anionic coated DNA-PEI-polyplexes were tested. Size and zeta-potential of the resulting polyplexes was assessed by DLS and microelectrophoresis, respectively. The toxicity of formed complexes to PANC-1 cells was assessed by measuring metabolic activity (AlamarBlue test). Polyplexes stability was evaluated in transfection experiments in the presence of serum on PANC-1 cells. Transfection efficiency was assessed by lacZ reporter gene expression biochemically and by flow cytometry analysis of GFP-expressing cells.

Results. Optimal charge ratio of DNA/PEI/anionic peptide was found to be 1/16/4. Polyplexes with all studied anionic peptides at this charge ratio are nontoxic for PANC-1 cells. Addition of peptides to PEI-polyplexes increases their stability when incubated with polyanions. Interestingly, almost all polyplexes at the chosen charge ratio were large in size (> 500 nm in diameter). Charge ratio of 1/16/4 is also the ratio at which the charge of polyplexes changes from positive to negative. Reporter genes products were detected in cells after transfection with these polyplexes, indicating successful delivery.

Conclusion. Study shows that the utilization of anionic peptide coating with PEI-polyplexes promotes successful transfection in the presence of serum. Developed modification should be considered as a universal module of non-viral delivery systems.

Introduction: Scientific evidence has shown that the electrical stimulation of the primary occipital cortex can evoke luminous visual perceptions known as phosphenes. This finding has provided the basis for the development of cortical visual prostheses for blind individuals. In this context, understanding and unveiling the cortical perceptual dynamics evoked during the process of perceiving phosphenes is crucial in order to improve the interaction between this technology and the user.

Methods: In this study, we investigated the cortical perceptual dynamics of three blind subjects who were implanted with a 10x10 Utah microelectrode array in their visual cortices. Cortical responses during the perception and non-perception of evoked phosphenes were monitored using electroencephalographic (EEG) techniques. Processing methods included the quantification of event-related synchronization/desynchronization (ERS/ERD) and directed transfer function (DTF)-based connectivity analysis.

Results and Discussion: The analysis of EEG signals revealed significant differences in ERS/ERD within the 1-to-45 Hz range (specifically between 4 to 7.5Hz), predominantly in frontal and prefrontal regions, when subjects perceive phosphenes. These differences were observed between 250 and 750 ms following stimulus application. Connectivity analysis based on DTF determination showed that phosphene perception evokes directional connections from temporal regions to central and frontal regions.

Conclusions: In this study, we demonstrated that EEG signals allow the characterization of cortical dynamics during phosphene perception. It was observed that, in terms of evoked oscillation energy, frontal areas exhibit higher synchronization during phosphene perception, while in terms of directional connectivity, cortical directional information shows cross-modulation when the phosphene is perceived.