Search Results (77)

Photobiomodulation (PBM) utilizes different wavelengths of light to modulate cellular functions and has emerged as a promising approach in regenerative medicine. In this study, we examined the effects of blue (455 nm), red (660 nm), and near-infrared (810 nm) light, both individually and in combination, on human adipose-derived mesenchymal stem/stromal cells (adMSCs). A single, short-term exposure of adMSCs in suspension to these wavelengths using an integrating sphere revealed distinct wavelength- and dose-dependent cellular responses. Blue light exposure led to a dose-dependent increase in intracellular reactive oxygen species, accompanied by reduced cell proliferation, metabolic activity, interleukin-6/interleukin-8 secretion, and adipogenic differentiation. In contrast, red and near-infrared light preserved cell viability and metabolic function while enhancing cell migration, consistent with their documented ability to stimulate proliferation and mitochondrial activity in mesenchymal stem cells. These findings highlight the necessity of precise wavelength and dosage selection in PBM applications and support the potential of PBM as a customizable tool for optimizing patient-specific regenerative therapies. Full article

Owing to its high energy efficiency, regenerative capability, and fast dynamic response, the Electromagnetic Energy-Feeding Shock Absorber has found widespread application in automotive suspension control systems. To further improve thrust control precision, this study presents a sliding mode thrust controller designed using an improved Gray Wolf Optimization algorithm. Firstly, an improved exponential reaching law is adopted, where a saturation function replaces the traditional sign function to enhance system tracking accuracy and stability. Meanwhile, a position update strategy from the particle swarm optimization (PSO) algorithm is integrated into the gray wolf optimizer (GWO) to improve the global search ability and the balance of local exploitation. Secondly, the improved GWO is combined with sliding mode control to achieve online optimization of controller parameters, ensuring system robustness while suppressing chattering. Finally, comparative analyses and simulation validations are conducted to verify the effectiveness of the proposed controller. Simulation results show that, under step input conditions, the improved GWO reduces the rise time from 0.0034 s to 0.002 s and the steady-state error from 0.4 N to 0.12 N. Under sinusoidal input, the average error is reduced from 0.26 N to 0.12 N. Under noise disturbance, the average deviation is reduced from 2.77 N to 2.14 N. These results demonstrate that the improved GWO not only provides excellent trajectory tracking and control accuracy but also exhibits strong robustness under varying operating conditions and random white noise disturbances. Full article

Facial aging is a multifactorial and stratified biological process characterized by progressive morphological and biochemical alterations affecting both cutaneous (Layer I) and subcutaneous (Layer II) tissues. These age-related changes manifest clinically as volume depletion, tissue ptosis, and a decline in overall skin quality. In response to these phenomena, thread lifting techniques have evolved significantly—from simple mechanical suspension methods to sophisticated bioactive platforms. Contemporary threads now incorporate biocompatible polymers and hyaluronic acid (HA), aiming not only to reposition soft tissues but also to promote dermal regeneration. This review provides a comprehensive classification and critical assessment of thread lifting materials, focusing on their chemical composition, mechanical performance, degradation kinetics, and biostimulatory potential. Particular emphasis has been given to the surface integration of HA into monofilament threads, especially with the emergence of advanced delivery systems such as NAMICA, which facilitate sustained HA release. Advanced thread materials, especially those fabricated from poly(L-lactide-co-ε-caprolactone) [P(LA/CL)], demonstrate both tensile support and regenerative efficacy. Emerging HA-covered threads exhibit synergistic bioactivity, stimulating skin remodeling. NAMICA technology represents an advancement in the field, in which HA is encapsulated within biodegradable polymer fibers to enable gradual release and enhanced dermal integration. Nonetheless, well-designed human studies are still needed to substantiate its therapeutic efficacy. Consequently, the paradigm of thread lifting is shifting from purely mechanical interventions toward biologically active systems that promote comprehensive ECM regeneration. The integration of HA into resorbable threads, especially when combined with sustained-release technologies, represents a meaningful innovation in aesthetic dermatology, meriting further preclinical and clinical evaluation. Full article

To enhance energy efficiency and reduce emissions in public transportation systems, this study proposes a novel electro-hydraulic energy-regenerative suspension system for urban buses. A comprehensive co-simulation framework was established to evaluate system performance. Targeting ride comfort and energy regeneration performance as dual optimization objectives, we conducted systematic parameter analysis through design-of-experiments methodology to identify critical structural parameters. To streamline multi-objective optimization processes, a particle swarm optimization–back propagation (PSO-BP) neural network surrogate model was developed to approximate the complex co-simulation system. Subsequent non-dominated sorting genetic algorithm II (NSGA-II) implementation enabled effective multi-objective optimization of key suspension parameters. Comparative simulations revealed that the optimized configuration achieves the following: (1) maintains ride comfort within human perception thresholds despite slight performance reduction, (2) enhances energy recovery efficiency, and (3) improves roll stability characteristics. These findings demonstrate the proposed system’s capability to balance passenger comfort with energy conservation and safety requirements. Full article

Energy harvesting in the automotive sector is a rapidly growing field aimed at improving vehicle efficiency and sustainability by recovering wasted energy. Various technologies have been developed to convert mechanical, thermal, and environmental energy into electrical power, reducing dependency on traditional energy sources. This manuscript provides a comprehensive review of energy harvesting applications/methodologies, aiming to trace the research lines and future developments. This work identifies the main categories of harvesting solutions, namely mechanical, thermal, and hybrid/environmental solar–wind systems; each section includes a detailed review of the technical and scientific state of the art and a comparative analysis with detailed tables, allowing the state of the art to be mapped for identification of the strengths of each solution, as well as the challenges and future developments needed to enhance the technological level. These improvements focus on energy conversion efficiency, material innovation, vehicle integration, energy savings, and environmental sustainability. The mechanical harvesting section focuses on energy recovery from vehicle vibrations, with emphasis on regenerative suspensions and piezoelectric-based solutions. Specifically, solutions applied to suspensions with electric generators can achieve power outputs of around 1 kW, while piezoelectric-based suspension systems can generate up to tens of watts. The thermal harvesting section, instead, explores methods for converting waste heat from an internal combustion engine (ICE) into electrical power, including thermoelectric generators (TEGs) and organic Rankine cycle systems (ORC). Notably, ICEs with TEGs can recover above 1 kW of power, while ICE-based ORC systems can generate tens of watts. On the other hand, TEGs integrated into braking systems can harvest a few watts of power. Then, hybrid solutions are discussed, focusing on integrated mechanical and thermal energy recovery systems, as well as solar and wind energy harvesting. Hybrid solutions can achieve power outputs above 1 kW, with the main contribution from TEGs (≈1 kW), compared to piezoelectric systems (hundreds of W). Lastly, a section on commercial solutions highlights how current scientific research meets the automotive sector’s needs, providing significant insights for future development. For these reasons, the research results aim to be guidelines for a better understanding of where future studies should focus to improve the technological level and efficiency of energy harvesting solutions in the automotive sector. Full article

Background and Objectives: Burn injuries, particularly partial-thickness burns, often require advanced therapies to improve re-epithelialization and scar quality. This study aims to evaluate the efficacy of autologous skin cell suspensions, such as Recell, compared to standard treatments in promoting faster and better-quality skin healing. Our goal is to provide evidence-based conclusions on the effectiveness of these regenerative approaches in burn treatment. Materials and Methods: During our comprehensive investigation, we systematically examined several databases for the period to November 2024, including PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials. Our primary objective was to assess the efficacy of autologous cell suspension in treatment for burn injuries. We employed the ROB2 method to assess the quality of evidence to ensure the validity of the conclusions derived from these studies. The gathered data were systematically organized in a standardized online format and analyzed with RevMan 5.4. Results: Our systematic literature search identified nine studies (n = 358 patients) evaluating the efficacy of autologous skin cell suspensions in promoting re-epithelialization in burn injuries. The meta-analysis revealed a statistically significant reduction in time to re-epithelialization in the autologous skin cell suspension group compared to the control group (MD = −1.71 days, 95% CI [−2.73, −0.70], p = 0.001), with moderate heterogeneity among the studies (I² = 58%). However, no significant differences were found in secondary outcomes, including postoperative pain (SMD = −0.71, 95% CI [−2.42, 1.00], p = 0.42), POSAS scores (MD = −0.35, 95% CI [−2.12, 1.42], p = 0.69), Vancouver Scar Scale (MD = −0.76, 95% CI [−2.86, 1.33], p = 0.48), or the incidence of complete healing by the 4th week (RR = 0.98, 95% CI [0.94, 1.02], p = 0.24). Similarly, no significant differences were found in postoperative infection rates (RR = 0.85, 95% CI [0.28, 2.60], p = 0.78) or the need for further interventions (RR = 0.15, 95% CI [0.02, 1.16], p = 0.07). Conclusions: autologous skin cell suspension significantly reduces the time to re-epithelialization in burn injuries compared to standard treatments. However, no significant differences were found in secondary outcomes, such as postoperative pain, scar quality (POSAS, Vancouver Scar Scale), complete healing rates, infection rates, or the need for additional interventions. While autologous skin cell suspension shows promise in accelerating re-epithelialization, it does not provide significant advantages over conventional methods in other clinical aspects. The results underscore the need for further research with larger, more robust studies to assess the long-term benefits of autologous skin cell suspension in burns carefully. Full article

Besides alternative surgical methods for bilateral limbal deficiency, such as KLAL (keratolimbal allograft), living-related conjunctival limbal allograft (LR-CLAL), and keratoprosthesis, regenerative medicine often necessitates the use of alternative sources of limbal cells in cases where access to fellow eye source cells is limited. Mucosal cells are most commonly used to restore limbal tissue in such scenarios. Current techniques involving mucosal cells include cultivated oral mucosal transplantation (COMT), oral mucosal graft transplantation (OMGT), and simple oral mucosal transplantation (SOMT). COMT requires suspension of cells and a culturing process that is time-consuming and cost-prohibitive. In contrast, OMGT requires solely a strip of mucosal graft for transplanting into the deficient eye. The most recently developed practice, SOMT, in which chopped biopsy tissue is transplanted into the deficient area, compensates for problems associated with both COMT and OMGT, making the process of addressing bilateral limbal deficiency easy, time-saving, and affordable. Although some undesirable outcomes, such as angiogenesis, can occur post-transplantation, and the ultimate goal of differentiation into limbal epithelial stem cells may not be achieved, mucosal cell sources can be a good alternative for stabilizing the ocular surface. Some studies emphasize that co-culturing limbal niches in mucosal cell cultures can enhance differentiation capability. This concept highlights the importance of the limbal environment in the differentiation process. In this review, we demonstrate the ongoing changes in surgical technique trends and how they have made mucosal cell transplantation easier and more effective for limbal regeneration. Full article

Hair follicle stem cells, located in the bulge region of the outer root sheath, are multipotent epithelial stem cells capable of differentiating into epidermal, sebaceous gland, and hair shaft cells. Efficient culturing of these cells is crucial for advancements in dermatology, regenerative medicine, and skin model development. This investigation aimed to develop a protocol for isolating enriched bulge-derived epithelial cells from scalp specimens to produce tissue-engineered substitutes. The epithelium, including hair follicles, was separated from the dermis using thermolysin, followed by microdissection of the bulge region. Epithelial stem cells were isolated using enzymatic dissociation to create a single-cell suspension and compared with the direct explant culture and a benchmark method which isolates cells from the epidermis and pilosebaceous units. After 8 days of culture, the enzymatic digestion of microdissected bulges yielded 5.3 times more epithelial cells compared to explant cultures and proliferated faster than the benchmark method. Cells cultured from all methods exhibited comparable morphology and growth rates. The fully stratified epidermis of tissue-engineered skin was similar, indicating comparable differentiation potential. This enzymatic digestion method improved early-stage cell recovery and expansion while maintaining keratinocyte functionality, offering an efficient hair bulge cell-extraction technique for tissue engineering and regenerative medicine applications. Full article

A pressure ulcer is the necrosis of the skin and tissues due to prolonged pressure. Its prevention and treatment are of great importance not only for the health but also for the patient’s quality of life and are considered the highest priority. In the present study, a reliable analytical method is developed for the quantitative determination of panthenol, hesperidin, rutin, and allantoin by HPLC and UV detectors. The substances were formulated into a pharmaceutical gel, with healing and regenerative properties recommended for first- and second-degree bedsores. Their separation was achieved with a ZIC-Hilic column (150 × 4.6 mm), 5 μm, and a gradient elution system (Solvent A: CH₃CN-H₂O, 90:10 v/v/v and Solvent B: CH₃CN-H₂O, 10:90 v/v). The method was evaluated based on the required specifications (%RSD < 2, % Recovery > 96.7%) and was applied for the quantitative extraction of the active substances in the gel. The purification of the samples was carried out using experimental design and Cross-D-Optimal methodology (%RSD < 2.2, % Recovery > 96.9%). Subsequently, the gel was studied in terms of the transdermal permeation of the active pharmaceutical ingredients (APIs) through vertical Franz cells and their behavior (P_app values) was compared with a similar aqueous suspension product (reference formulation). The samples were reconstituted by lyophilization and extraction with methanol. According to the results, the drugs exhibit satisfactory penetration, ensuring the healing of problems that may occur in the skin and dermis. Full article

Adipose-derived stromal cells (ASCs) possess significant regenerative potential, playing a key role in tissue repair and angiogenesis. During wound healing, ASC interacts with the extracellular matrix by recognizing arginylglycylaspartic acid (RGD) motifs, which are crucial for mediating these functions. This study investigates how RGD exposure influences ASC behavior, with a focus on angiogenesis. To mimic the wound-healing environment, ASC were cultured in a porcine gelatin sponge, an RGD-exposing matrix. Transcriptomics revealed that ASC cultured in gelatin exhibited an upregulated expression of genes associated with inflammation, angiogenesis, and tissue repair compared to ASC in suspension. Pro-inflammatory and pro-angiogenic factors, including IL-1, IL-6, IL-8, and VEGF, were significantly elevated. Functional assays further demonstrated that ASC-conditioned media enhanced endothelial cell migration, tubulogenesis, and reduced endothelial permeability, all critical processes in angiogenesis. Notably, ASC-conditioned media also promoted vasculogenesis in human vascular organoids. The inhibition of ASC-RGD interactions using the cyclic peptide cilengitide reversed these effects, underscoring the essential role of RGD-integrin interactions in ASC-mediated angiogenesis. These findings suggest that gelatin sponges enhance ASC’s regenerative and angiogenic properties via RGD-dependent mechanisms, offering promising therapeutic potential for tissue repair and vascular regeneration. Understanding how RGD modulates ASC behavior provides valuable insights into advancing cell-based regenerative therapies. Full article

This article introduces a novel regenerative suspension system designed for active seat suspension, to reduce vibrations while recovering energy. The system employs a four-quadrant electric actuator operation model and utilizes a brushless DC motor as an actuator and an energy harvester. This motor, a permanent magnet synchronous type, transforms DC into three-phase AC power, serving dual purposes of vibration energy recovery and active power generation. The system’s advanced vibration control is achieved through the switching of MOSFET transistors, ensuring the suspension system meets operational criteria that contrast with traditional vibro-isolation systems, thereby reducing the negative effects of mechanical vibrations on the human body, while also lowering energy consumption. Comparative studies of the regenerative system dynamics against passive and active systems under random vibrations demonstrated its effectiveness. This research assessed the system’s performance through power spectral density and transmissibility functions, highlighting its potential to enhance energy efficiency and the psychophysical well-being of individuals subjected to mechanical vibrations. The effectiveness of the energy regeneration process under the chosen early excitation vibrations was investigated. Measurements of the motor torque in the active mode and during regenerative braking mode, and the corresponding phase currents of the motor, are presented. Full article

The energy efficiency of vehicles is a crucial challenge relating to sustainable energy preservation and regeneration methods. Regenerative breaking has proven feasible, and there is interest in whether harvesting energy from a vehicle’s suspension is similarly feasible. We here provide methods for estimating the amount of power that can be regenerated from the suspension for given vehicle and road parameters. We show that a reasonable road model is a generalised Gaussian process known as AR(1). Using this model, we can derive the key equation used in the ISO 8608 standard for measuring road roughness, such that the AR(1) parameters can be related to the measured road roughness data. We find that the road roughness coefficient of ISO 8608 and the diffusion coefficient of the AR(1) road are equal up to a factor. We provide an analytical expression for the maximum amount of power that can be generated for given road and car parameters, derived via Fourier analysis. We further model harvesting from large bumps using Simulink. These results help to estimate the potential power output given the measured road data. Full article

This study primarily investigates the adaptability and performance of hydraulic–electric regenerative dampers for high-speed trains by substituting conventional primary dampers with hydraulic–electric regenerative dampers. The primary objectives are to develop a detailed model of primary suspension regenerative damper (PSRD) energy conversion that incorporates factors such as oil pressure loss, motor efficiency, and overall system efficiency, and to perform a comprehensive comparative analysis of vibration responses, wheel wear, comfort indices, and power generation using an integrated MATLAB and SIMPACK co-simulation platform. The results reveal that at an operational speed of 350 km/h, the dynamic responses of the carbody, bogie, wheelset, and dampers equipped with the proposed PSRD systems closely align with those of conventional primary vertical damper systems. The detailed PSRDs’ hydraulic–mechanical–electrical model effectively captures the subtleties of oil pressure fluctuations and their impacts. The wear distribution and magnitude across the vehicle remain consistent during acceleration, constant, and deceleration speeds, ensuring uniform wear characteristics. Under real-world railway operational conditions, the ride comfort metrics of vehicles fitted with regenerative dampers are comparable to those with conventional primary vertical dampers. Furthermore, each regenerative damper can generate up to 21.72 W of electrical power, achieving a generation efficiency of 45.28%. Finally, a test rig was designed and fabricated to validate the primary suspension regenerative damper (PSRD) model, showing good agreement between predicted and actual damping force and power regeneration, with results indicating a peak damping force of 12.5 kN and approximately 230 W of regenerated power. This research provides a theoretical foundation and experimental validation for implementing power regeneration mechanisms in railway transportation, demonstrating that the hydraulic–mechanical–electrical PSRD model can fulfil the performance criteria of conventional dampers while offering substantial energy harvesting capabilities. This advancement not only enhances energy efficiency but also contributes to the sustainable development of high-speed rail systems. Full article

Reducing vehicle energy consumption is crucial for sustainable development, especially in the context of energy crises and environmental pollution. Energy regenerative suspension offers a promising solution, yet its practical implementation faces challenges like inertial mass issues, cost, and reliability concerns. This study introduces a novel suspension configuration, optimizing shock absorber technology with energy regenerative principles. The objective is to drastically cut energy consumption. Through a frequency domain analysis, this study identifies the root causes of increased energy consumption and worsened vibration in traditional suspensions. This study presents a comparative analysis of the frequency-domain characteristics between the novel suspension configuration and the traditional one. This study reveals that the new configuration exhibits a low-pass filtering effect on the shock absorber’s velocity, effectively minimizing vibrations in the low-frequency range, while mitigating their impact in the high-frequency range. This approach mitigates the trade-off between increased energy consumption and worsened vibration in the high-frequency range, making it a promising solution. Simulations show that this configuration significantly reduces acceleration by 7.04% and suspension power consumption by 10.47% at 60 km/h on the D-level road, while maintaining handling stability. This makes it a promising candidate for future energy-efficient suspension systems. Full article

Background and Objectives: This three-year clinical trial aimed to demonstrate that only the signaling vesicles produced by ADSCa, containing mRNA, microRNA, growth factors (GFs), and bioactive peptides, provide an advantage over classical therapy with adipose disaggregate to make the tissue regeneration technique safer due to the absence of interfering materials and cells, while being extremely minimally invasive. The infiltration of disaggregated adipose nanofat, defined by the Tonnard method, for the regeneration of the dermis and epidermis during physiological or pathological aging continues to be successfully used for the presence of numerous adult stem cells in suspension (ADSCa). An improvement in this method is the exclusion of fibrous shots and cellular debris from the nanofat to avoid inflammatory phenomena by microfiltration. Materials and Methods: A small amount of adipose tissue was extracted after surface anesthesia and disaggregated according to the Tonnard method. An initial microfiltration at 20/40 microns was performed to remove fibrous shots and cellular debris. The microfiltration was stabilized with a sterile solution containing hyaluronic acid and immediately ultrafiltered to a final size of 0.20 microns to exclude the cellular component and hyaluronic acid chains of different molecular weights. The suspension was then injected into the dermis using a mesotherapy technique with microinjections. Results: This study found that it is possible to extract signaling microvesicles using a simple ultrafiltration system. The Berardesca Scale, Numeric Rating Scale (NRS), and Modified Vancouver Scale (MVS) showed that it is possible to obtain excellent results with this technique. The ultrafiltrate can validly be used in a therapy involving injection into target tissues affected by chronic and photoaging with excellent results. Conclusions: This retrospective clinical evaluation study allowed us to consider the results obtained with this method for the treatment of dermal wrinkles and facial tissue furrows as excellent. The method is safe and an innovative regenerative therapy as a powerful and viable alternative to skin regeneration therapies, antiaging therapies, and chronic inflammatory diseases because it lacks the inflammatory component produced by cellular debris and fibrous sprouts and because it can exclude the mesenchymal cellular component by reducing multiple inflammatory cytokine levels. Full article