Search Results (137)

Driven by societal and technological progress, the polymer tubing industry is increasingly focused on sustainable and biodegradable products, with polylactic acid (PLA)-based microtubes gaining attention for applications such as medical stents and disposable straws. However, their inherent mechanical limitations, especially under hoop loading and the brittleness of PLA, restrict broader use. Although two-dimensional nanofillers can enhance polymer properties, conventional extrusion only creates uniaxial alignment, leaving fillers randomly oriented in the radial plane and failing to improve hoop performance. To address this, we developed a rotational extrusion strategy that superimposes a rotational force onto the conventional axial flow, generating a biaxial stress field. By adjusting rotational speed to regulate hoop stress, a concentric, interlocked graphene oxide network in a PLA/polybutylene adipate terephthalate microtube is induced along the circumferential direction without disturbing its axial alignment. This architecturally tailored structure significantly enhances hoop mechanical properties, including high compressive strength of 0.54 MPa, excellent low-temperature impact toughness of 0.33 J, and improved bending resistance of 30 N, while maintaining axial mechanical strength exceeding 50 MPa. This work demonstrates a scalable and efficient processing route to fabricate high-performance composite microtubes with tunable and balanced directional properties, offering a viable strategy for industrial applications in medical, packaging, and structural fields. Full article

Coronary artery disease (CAD) remains one of the leading causes of mortality worldwide, affecting more than 300 million people. Over the past two decades, percutaneous coronary intervention (PCI) has become the cornerstone of CAD treatment, involving the implantation of coronary stents. This review clarifies how coronary stents emerged, evolved, and ultimately reshaped modern interventional cardiology. Beginning with balloon angioplasty and progressing through bare-metal and drug-eluting stents, we show how each advancement solved key clinical shortcomings—dramatically reducing restenosis, thrombosis, and repeat revascularization. We further review the major technological advances driving modern stent development, such as biodegradable alloys and biomimetic coatings. We also highlight the remaining challenges, including long-term stability, manufacturing complexity, and limited translational readiness. Together, these elements support our central thesis: that the historical evolution of coronary stents is fundamental to understanding present PCI practice and to guiding the next phase of device innovation. Full article

Traditional drug delivery methods for gastrointestinal diseases, including oral and systemic administration, often suffer from degradation, inadequate mucosal absorption, and off-target toxicity. Consequently, these methods result in low bioavailability and suboptimal therapeutic outcomes for localized conditions such as inflammation and early-stage cancer. This review examines the innovative integration of advanced bioengineering platforms with therapeutic gastrointestinal endoscopy to address these delivery challenges. We concentrate on three principal bioengineered platforms: (1) nanoparticle systems (e.g., lipid, polymeric, and inorganic nanoparticles) designed for localized chemotherapy and theranostics; (2) in situ-forming hydrogels that serve as intelligent wound management materials and sustained drug depots; and (3) drug-eluting and biodegradable stents that convert passive luminal scaffolds into active, long-term drug-releasing devices. An analysis of these platforms demonstrates that their synergy with endoscopy facilitates precise, minimally invasive, and sustained local therapy, potentially transforming the treatment landscape for gastrointestinal diseases such as cancer and inflammatory bowel disease. Additionally, we investigate advanced strategies, including active targeting and stimulus-responsive release mechanisms, to enhance spatial precision. Despite promising preclinical advancements, clinical translation encounters challenges related to long-term biocompatibility, scalable manufacturing, regulatory pathways for drug-device combinations, and cost-effectiveness. Ultimately, the convergence of bioengineering and endoscopy presents significant potential to usher in a new era of precise, localized, and sustained micro-invasive treatments in gastroenterology. Full article

Background/Objectives: Diabetes mellitus (DM), especially insulin-dependent DM (IDDM), is strongly associated with adverse outcomes following percutaneous coronary intervention (PCI) failure. Polymer-free drug-eluting stents (PF-DESs) have emerged as a promising strategy to mitigate long-term coronary inflammation. This study aimed to evaluate the role of PF-DES, as compared to permanent-polymer DES (PP-DES) and biodegradable-polymer DES (BP-DES), in a real-world cohort of IDDM patients with obstructive coronary artery disease (CAD) undergoing PCI. Methods: IDDM patients with CAD who underwent PCI with DES at Parma University Hospital were divided into two study groups: PF-DES group vs. BP/PP-DES group. The primary endpoint was target vessel failure (TVF) at the 4-year follow-up. Survival analyses and propensity score matching (PSM) were performed to account for baseline differences. Results: A total of 170 IDDM patients with 215 treated lesions (31.6% PF-DES; 68.4% BP/PP-DES) were included. The PF-DES group experienced significantly lower rates of TVF (10.3% vs. 27.2%, p < 0.01, log rank p = 0.0072) compared with the BP/PP-DES group. PSM analysis confirmed the good clinical performance of PF-DES (HR 0.27, p < 0.01). Conclusions: In this PSM-based observational study, PF-DESs were associated with significantly lower rates of TVF compared with BP/PP-DESs in IDDM patients undergoing PCI for CAD. These suggest that PF-DES may represent a personalized PCI strategy for IDDM patients, with prognostic benefits that become increasingly pronounced as the clinical and anatomical risk profile worsens. Full article

Novel pure Zn and Zn-3Ag-xFe (x = 0, 1, 3, 5) (wt.%) nanocrystalline powders were synthesized for potential use as implants and stent materials by the mechanical alloying (MA) technique. The morphological and structural alterations of the powders milled for 5, 10, and 20 h were examined. SEM research revealed that during MA, the original elemental powder particles were subjected to a cold-welding process, subsequently fracturing in a brittle manner. The EDX spectra of the powders milled for 20 h indicated a uniform distribution of components. Laser diffraction particle size examination proved that the Zn-3Ag-1Fe alloy had the smallest particle size at 58.8 µm. XRD examination indicates the existence of AgZn₃ and Fe₃Zn₁₀ intermetallic phases. The crystallite size diminishes with prolonged milling time, decreasing from 130 nm to 30 nm. The porosity rose from 11.62% for pure Zn to 15.35% in the Zn-3Ag-5Fe alloy, suggesting that the incorporation of Ag and the higher Fe ratio diminished the compressibility of the milled powders, as evidenced by density tests. The Zn-3Ag-5Fe alloy exhibited the maximum corrosion current density of 164.65 µA/cm², attributed to the microgalvanic effect and reduced relative density induced by the Fe₃Zn₁₀ phase, which escalated with higher Fe doping. The hardness of the Zn-3Ag-5Fe alloy rose from 34.5 ± 2.8 HV to 132.2 ± 4.6 HV compared to the pure Zn sample, while the wear coefficient decreased from 0.029 ± 0.003 mm³/Nm to 0.005 ± 0.001 mm³/Nm, corresponding with the hardness test results. In contrast to S. aureus, which exhibited an 87.8% susceptibility to antibacterial activity from 3% silver and iron additions, E. coli demonstrated over 85% susceptibility to antibacterial activity from silver addition alone. The Zn-3Ag and Zn-3Ag-1Fe samples demonstrated high biocompatibility, attaining cell survival rates of 99.2% ± 3.01% and 99.2% ± 4.02% for the 12.5% extract, respectively. This study demonstrates that the newly developed Zn-Ag-xFe alloys have exceptional mechanical properties and excellent biocompatibility. Furthermore, the variable biodegradation rate dependent on alloy type presents an avenue for further research. Full article

This paper presents recent progress (2019–2025) in the role of polymer-based sensors implemented for heart and blood vessel monitoring. The existing variety of polymers, of synthetic and natural origin, allows the creation of sensors tailored to specific needs, to monitor heart health status for invasive cardiovascular surgery. Polymers, in combination with nanomaterials, nanostructures, or nanostructured materials, enhance the characteristics of force sensors. The review discusses implantable sensors applied in healthcare, especially for cardiovascular system monitoring, which provide the possibility to prevent the development of pathology or to control existing pathology. Additionally, the emerging need for biodegradable devices requires a review of the polymers already used. The quality and accuracy requirements of sensors for self-monitoring and health status control in medical institutions vary; yet needing a variety of sensors does not reduce the importance of finding sensors that are more accurate or more comfortable to wear. Sensors suitable for short-term use become important in the postoperative period, with the need for biodegradable polymers. This review focuses on publications that provide an analysis of the sensors as well as their potential for medical purposes. Our review focuses on polymers applied to force sensors for cardiovascular system monitoring. Overall, this review explores the paths of innovations in the field of novel technologies for self-monitoring of health. Finally, future research directions reported in the selected articles for cardiovascular care sensors are discussed. Full article

Hydrogels are hydrophilic, soft polymer networks with high water content and mechanical properties that are tunable; they are also biocompatible. Therefore, as biomaterials, they are of interest to modern medicine. In this review, the main applications of hydrogels in essential clinical applications are discussed. Chemical, physical, or hybrid crosslinking of either synthetic or natural polymers allow for the precise control of hydrogels’ physicochemical properties and their specific characteristics for certain applications, such as stimuli-responsiveness, drug retention and release, and biodegradability. Hydrogels are employed in gynecology to regenerate the endometrium, treat infections, and prevent pregnancy. They show promise in cardiology in myocardial infarction therapy through injectable scaffolds, patches in the heart, and medication delivery. In rheumatoid arthritis, hydrogels act as drug delivery systems, lubricants, scaffolds, and immunomodulators, ensuring effective local treatment. They are being developed, among other applications, as antimicrobial coatings for stents and radiotherapy barriers for urology. Ophthalmology benefits from the use of hydrogels in contact lenses, corneal bandages, and vitreous implants. They are used as materials for chemoembolization, tumor models, and drug delivery devices in cancer therapy, with wafers of Gliadel presently used in clinics. Applications in abdominal surgery include hydrogel-coated meshes for hernia repair or Janus-type hydrogels to prevent adhesions and aid tissue repair. Results from clinical and preclinical studies illustrate hydrogels’ diversity, though problems remain with mechanical stability, long-term safety, and mass production. Hydrogels are, in general, next-generation biomaterials for regenerative medicine, individualized treatment, and new treatment protocols. Full article

Coronary artery disease (CAD) remains a major cause of mortality worldwide. Among the standard therapeutic approaches are percutaneous coronary interventions (PCI) employing stents. The main limitation of the procedure lies in the permanent stiffening of the vessel wall. The DynamX Bioadaptor, representing a new generation of vascular stents, combines the advantages of standard implants with a unique mechanism—“uncaging.” Its helical structure, linked by a biodegradable material, enables the restoration of the vessel’s natural functions. This breakthrough concept in interventional cardiology holds the potential to establish a new standard of care for patients suffering from CAD. In this work, we aim to synthesize the available evidence concerning the characteristics of the DynamX Bioadaptor and its impact on vascular physiology. We provide a comprehensive review and evaluation of current clinical reports on its use, analyzing the available literature in comparison with other stent technologies. Recognizing that the DynamX Bioadaptor is a relatively recent innovation, we also seek to identify existing gaps in the literature and propose future directions for research to fully assess its long-term clinical potential. Full article

Mg alloys hold promise for biodegradable gastrointestinal implants, but most evaluations rely on simplified media like Hank’s solution, which lacks organic components and fails to replicate the acidic-to-alkaline transition of intestinal fluid, risking underestimation of biodegradation rates and clinical relevance. This work investigated a trace-Cu-modified Mg alloy (Mg-0.05Cu) in simulated intestinal fluid (SIF) versus Hank’s solution. Microstructural analysis confirmed Mg₂Cu intermetallic phases as Cu reservoirs. Electrochemical and immersion tests revealed significantly accelerated biodegradation in SIF, due to its disruption of protective layer formation, sustaining loose biodegradation products. The biodegradation rate of the trace-Cu-modified Mg alloy in SIF was consistent with reported values for Mg alloys in similar media, as was that in Hank’s solution. Remarkably, Mg-0.05Cu exhibited potent antibacterial activity against E. coli, achieving 99.3% eradication within 12 h and 100% elimination by 24–48 h, alongside excellent cytocompatibility with L929 cells (>95% viability). This efficacy arose from the synergistic Cu²⁺ release and high-pH microenvironment. These findings demonstrate that trace Cu alloying in high-purity Mg balances rapid antibacterial action with controlled biodegradation in a physiologically relevant SIF. This positions Mg-0.05Cu as a highly promising candidate for practical applications, such as biodegradable intestinal stents, anti-adhesion barriers, anastomosis rings, and anti-obesity devices, where rapid infection control and predictable degradation are critical for clinical success. This work underscores the importance of using biomimetic media for evaluating gastrointestinal implants and establishes Mg-0.05Cu as a promising strategy for developing infection-resistant biodegradable devices. Full article

Cardiovascular disease is a leading cause of global mortality. Percutaneous coronary intervention, which involves the placement of stents to restore blood flow in narrowed arteries, is a widely used treatment. However, traditional stents, such as bare metal stents and drug-eluting stents, can lead to long-term complications such as restenosis, inflammation, and thrombosis. Biodegradable metallic vascular stents, with their superior mechanical properties, excellent biocompatibility, and gradual degradation in vivo, hold significant potential for the treatment of coronary artery disease. This review provides a comprehensive overview of the current research status and challenges. Firstly, it outlines the design principles and performance evaluation methods for biodegradable stents, which focus on mechanical properties, chemical characteristics, corrosion behavior, and biocompatibility. Furthermore, it summarizes the material features, degradation mechanisms, and metabolic behavior of three primary biodegradable metals—magnesium alloys, iron alloys, and zinc alloys—and discusses critical issues such as the degradation rate of different alloys and the development of zinc alloys. Finally, based on the current achievements and challenges of studies on biodegradable metal-based stents, this article proposes some optimization strategies and research prospects. Full article

Endotracheal prosthesis placement is employed as a therapeutic intervention for tracheal lesions in cases where conventional surgical approaches are not feasible. The learning curve for endotracheal stent placement can vary depending on the type of stent, the training environment, and the clinician’s prior experience; however, it is generally considered moderately complex. Inadequate practice can have serious consequences, as the procedure involves a critical area such as the airway. The main risks and complications associated with inadequate technique or improper execution can include stent migration, formation of granulation tissue or hyperplasia, tracheal or pulmonary infection, obstruction or fracture of the stent, hemorrhage and tracheal perforation, among others. The purpose of the present study is to summarize important information and evaluate the role of different material features in the 3D printing manufacturing of an appropriate tracheobronchial medical device, which should be as appropriate as possible to facilitate placement during surgical practice. A complex stent design was fabricated using three different biodegradable materials, polycaprolactone (PCL), polydioxanone (PDO), and polymer blend of polylactic acid/polycaprolactone (PLA/PCL), through additive manufacturing, specifically fused filament fabrication (FFF)3D printing. Parameter optimization of the 3D printing process was required for each material to achieve an adequate geometric quality of the stent. Experimental analyses were conducted to characterize the mechanical properties of the printed stents. Flexural strength and radial compression resistance were evaluated, with particular emphasis on radial force due to its clinical relevance in preventing collapse after implantation in the trachea. The results provide valuable insights into how material selection could influence device behavior during placement to support surgical requirements. Full article

Restenosis is the main cause of failure after stent implantation during angioplasty. The localized, sustained delivery of an antirestenotic drug may reduce smooth muscle cell (SMCs) proliferation and thereby limit neointimal hyperplasia. The aim of this study was to develop degradable sirolimus-eluting polymer coatings that can be applied on bioresorbable polymer-based scaffolds via an ultrasonic coating system. This is a novel approach because the detailed analysis of the coating procedure on bioresorbable polymeric scaffolds with the use of an ultrasonic system has not been reported thus far. It has been observed that the ultrasonic technique facilitates formation of a smooth coating, well-integrated with the scaffold. However, the drug dose is affected by the concentration of the coating solution and the number of layers. Therefore, these parameters can be used for tailoring the drug dose and release process. Although all types of the developed coatings provided sirolimus elution for at least 3 months, a more uniform, diffusion-controlled release profile was observed from coatings obtained from the 1.0% polymeric solution. The released drug showed antiproliferative activity against vascular SMCs, without any hemolytic or thrombogenic effects. The results of the study may be advantageous for further progress in the development and medical translation of polymeric vascular scaffolds with antirestenotic activity. Full article

Vein graft restenosis remains a major complication following coronary artery bypass grafting (CABG), mainly due to the abnormal proliferation of vascular smooth muscle cells (VSMCs) and impaired endothelial repair. While external stents (eStents) can provide mechanical support and limit adverse remodeling, traditional metallic stents are non-degradable and may induce chronic inflammation and fibrosis. In contrast, many bioresorbable materials degrade too quickly or lack mechanical strength. These challenges highlight the need for external stents that combine sufficient mechanical strength with biodegradability to support long-term graft patency. This is the first study that develops a chlorogenic acid–strontium (SrCA)-loaded polycaprolactone bioresorbable eStent that inhibits VSMC proliferation and enhances endothelial repair via Hippo–Yes-associated protein (YAP) signaling, addressing vein graft restenosis post-CABG. Combining mechanical support and biodegradability, it overcomes the limitations of non-degradable stents and rapidly degrading biomaterials, elucidates the potential of natural polyphenol–metal ion complexes in vascular remodeling, and offers an innovative strategy for the prevention of vein graft restenosis. Full article

Biodegradable vascular stents (BVSs) face challenges related to inadequate mechanical strength, which can lead to adverse clinical outcomes. Improving the mechanical behavior of biodegradable vascular stents through structural design has been extensively explored. However, the corresponding effects of these mechanical enhancements on degradation characteristics remain under-investigated. The present work focuses on examining how different stent design strategies affect the mechanical behavior and degradation characteristics of poly (lactic acid) (PLA) stents. The commercial PLA stent DESolve was adopted, and nine modified stents were constructed based on the geometrical configuration of the DESolve stent. The mechanical properties of the modified stents during radial crimping and three-point bending simulations were thoroughly studied. The degradation dynamics of the stents were characterized by four indices (i.e., mean number average molecular weight, residual volume fraction, mean von Mises stress, and stent diameter). The results indicated that both the widening ratio and direction affected the mechanical performance of the stents by increasing the radial stiffness and radial strength, minimizing recoil%, and decreasing the bending flexibility. Although the widening direction had a relatively minor influence on stent degradation, the associated increase in material volume contributed to an improved volumetric integrity and enhanced lumen preservation. This study established a theoretical basis for evaluating both the mechanical and degradation behaviors of PLA stents, offering valuable insights for future structural design optimization. Full article

Magnesium alloy stents exhibit significant potential in the treatment of cardiovascular and cerebrovascular diseases due to their remarkable mechanical support and biodegradability. However, bare magnesium alloy stents often degrade too quickly and exhibit inadequate biocompatibility, which severely restricts their clinical applicability. Herein, a composite coating consisting of an MgF₂ conversion layer, a polydopamine (PDA) layer, fucoidan, and hyaluronic acid was prepared to enhance the corrosion resistance and biocompatibility of ZE21B alloy for a vascular stent application. The modified ZE21B alloy exhibited relatively high surface roughness, moderate wettability, and better corrosion resistance. Moreover, the modified ZE21B alloy with a low hemolysis rate and fibrinogen adsorption level confirmed improved hemocompatibility for medical requirements. Furthermore, the ZE21B alloy modified with fucoidan and hyaluronic acid enhanced the adhesion, proliferation, and NO release of endothelial cells (ECs). Simultaneously, it inhibits the adhesion and proliferation of smooth muscle cells (SMCs), promoting a competitive advantage for ECs over SMCs due to the synergistic effects of fucoidan and hyaluronic acid. The incorporation of fucoidan and hyaluronic acid markedly improved the corrosion resistance and biocompatibility of the ZE21B magnesium alloy. This development presents a straightforward and effective strategy for the advancement of biodegradable vascular stents. Full article