Search Results (3,042)

Four-dimensional (4D) printing integrates additive manufacturing with stimuli-responsive materials to fabricate biomedical implants and functional healthcare devices that undergo programmed, time-dependent changes in shape or function. Unlike static 3D-printed constructs, 4D-printed systems can respond to clinically relevant stimuli such as temperature, hydration, pH, light (including near-infrared), magnetic fields, or electrical inputs. These triggers drive defined actuation mechanisms, most commonly thermomechanical shape-memory recovery, swelling-induced morphing, and magnetothermal activation. This review synthesizes the principal material platforms used for biomedical 4D printing, including shape-memory polymers and alloys, hydrogels, liquid-crystal elastomers, and responsive composites, and links material choice to device behavior and translational feasibility. Applications are discussed across self-expanding stents, cardiac occluders, tissue-engineered constructs, implantable drug delivery systems, and adaptive wearables. Key translational challenges include sterilization compatibility, manufacturing reproducibility and quality control, safe stimulus delivery, predictable biodegradation and long-term biocompatibility, and regulatory pathway definition. Full article

This study focuses on the development and characterization of advanced composite materials based on poly(ε-caprolactone) (PCL) and poly(vinylidene fluoride) (PVDF), with or without silver nanoparticles (AgNPs), planned for peripheral nerve or bone regeneration. The complementary properties of PCL (biocompatibility and biodegradability) and PVDF (mechanical stability and piezoelectric functionality) were exploited by blending the polymers in different ratios, resulting in binary (PCL/PVDF) and ternary (PCL/PVDF/AgNPs) composites. Green-synthesized AgNPs were integrated to enhance antimicrobial activity and to support tissue repair through improved signal transmission. Functional thin films and electrospun fibres were obtained and subjected to advanced characterization techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermal analysis. The results demonstrated appropriate morphology, chemical composition, structural stability, and favourable interactions with simulated physiological media. Preliminary biocompatibility assays confirmed good cell viability, supporting the biomedical applicability of the designed scaffolds. Overall, the obtained results highlight the potential of AgNPs-functionalized PCL/PVDF binary and ternary composites as promising candidates for flexible, durable, and bioactive implants in peripheral nerve or bone regeneration. Full article

Modification of PLA with functional nanoparticles is a promising approach for imparting new properties to the material. In this work, titanium nanoparticles (Ti NPs) and titanium dioxide nanoparticles (TiO₂ NPs) were synthesized by laser ablation and characterized by dynamic light scattering, spectrophotometry, and transmission electron microscopy. The average hydrodynamic diameter of Ti NPs was 12 nm, while that of TiO₂ NPs was 24 nm; both dispersions possessed a positive zeta potential (23–27 mV) and spherical morphology. L-PLA composite films containing 0.1 wt.% Ti NPs or TiO₂ NPs were obtained by solution casting. Atomic force and modulation-interference microscopy confirmed the uniform distribution of nanoparticles within the polymer matrix, although partial aggregation was observed. The introduction of TiO₂ NPs increased the water contact angle. Mechanical testing revealed a significant reinforcing effect: the addition of 0.1 wt.% NPs increased the Young’s modulus by 62–68% and the ultimate tensile strength by 16–18% while maintaining a ductile fracture pattern with elongation at break up to ~8%. Both types of composites generated reactive oxygen species (ROS) in aqueous solutions: Ti NPs increased H₂O₂ production by 5.5 times and TiO₂ NPs by 4.9 times, and they also induced the formation of hydroxyl radicals. The accumulation of 8-oxoguanine in DNA and long-lived oxidized protein species confirmed the materials’ ability to cause oxidative damage to biomacromolecules. For E. coli, growth inhibition reached 40.5% (for composites with Ti NPs) and 71% (for composites with TiO₂ NPs). The effect was even more pronounced for S. aureus, where inhibition levels were approximately 70% and 80%, respectively; flow cytometry confirmed the strong bactericidal effect, showing that materials containing TiO₂ NPs increased the proportion of dead cells to 25% for E. coli and ~68% for S. aureus. Cytotoxicity assessment on human fibroblasts (HSF) demonstrated the high biocompatibility of neat L-PLA and composites with Ti NPs (viability > 95%) and with TiO₂ NPs (viability ~93%). The obtained results indicate that L-PLA-based composites with Ti NPs and TiO₂ NPs exhibit pronounced ROS-mediated antibacterial activity without additional UV irradiation. These findings position these materials as highly promising candidates for active biodegradable food packaging to extend shelf-life and for biomedical devices, such as wound dressings and implants, where reducing the risk of bacterial colonization is critical. Full article

The reconstruction of complex orbitomaxillary defects requires biomaterials that can simultaneously provide structural stability, biocompatibility, and accurate restoration of facial volume and contour. While rigid polymers such as polyetheretherketone (PEEK) offer reliable mechanical support, they do not adequately replicate the viscoelastic behavior of soft tissues. This report presents a translational revision case employing a personalized hybrid biomaterial approach that combines a 3D-printed PEEK implant for structural orbital floor support with a patient-specific polydimethylsiloxane (PDMS) implant for malar volumetric augmentation. Reconstruction was planned using CT segmentation and contralateral mirroring. Patient-specific implants were subsequently designed using CAD/CAM techniques, combining a rigid PEEK implant for structural orbital support with a flexible PDMS implant for malar volumetric augmentation with complementary mechanical properties. Revision surgery included the removal of inadequately positioned titanium hardware, the release of incarcerated extraocular muscles, and the restoration of orbital anatomy and facial symmetry. Postoperative imaging demonstrated stable implant positioning and sustained orbitomaxillary stability. Despite successful anatomical reconstruction, residual functional sequelae, including strabismus related to the severity of the initial orbital trauma, persisted and were addressed separately in a staged manner, resulting in satisfactory ocular alignment and resolution of diplopia in primary gaze. This case underscores the complementary functional roles of rigid and elastic polymers and highlights the translational potential of PDMS as a permanent, patient-specific implant material for volumetric and contour restoration in craniofacial reconstruction. Full article

Alginate is a biocompatible and biodegradable polymer derived from seaweed. It has been extensively researched and developed for various applications. However, its poor mechanical properties present a significant drawback that limits its use in multiple fields. Furthermore, the fabrication of reinforced alginate films using conventional melt processing has the potential for scaling up production. This study aimed to enhance the mechanical properties of sodium alginate (SA) films by incorporating calcium alginate (CA) powder. The SA/CA biocomposite films were created using a thermo-compression technique, with glycerol acting as a plasticizer for the SA matrix. Various CA contents—2.5, 5, 10, and 20 wt%—were investigated. Scanning electron microscopy and energy dispersive spectroscopy revealed good interfacial adhesion between the SA film matrix and the CA powder. As the CA content increased, the moisture content of SA/CA biocomposite films decreased. The addition of CA powder significantly improved the tensile properties of the SA films. Based on the tensile test, SA/CA biocomposite films with 20 wt% CA powder exhibited a maximum tensile strength of 11.7 MPa and a Young’s modulus of 234.7 MPa. These results indicate a substantial increase of 208% in maximum tensile strength and 907% in Young’s modulus compared to SA films without CA. These findings indicated that the CA powder serves as an effective reinforcing filler for thermo-compressed SA films, which could lead to the development of high-strength alginate-based products for potential use in various applications, including biomedical, agricultural, and packaging applications. Full article

Antimicrobial resistance (AMR) represents one of the major threats to global health, driven by the indiscriminate use of antibiotics and decline in the development of new therapeutic agents. In this context, essential oils (EOs) have emerged as innovative natural alternatives due to their broad-spectrum antimicrobial activity and low potential to induce bacterial resistance. However, their clinical application is limited by their volatility, low chemical stability, and rapid degradation. The incorporation of EOs into electrospun natural polymer fibers has emerged as an effective strategy to overcome these limitations, improving their stability, enabling controlled release, and enhancing their antimicrobial efficiency. This review focuses on the use of electrospun natural polymers for biomedical applications, highlighting their biocompatibility, biodegradability, and ability to mimic the extracellular matrix, thereby promoting cell interaction. Additionally, their high surface area and porous structure facilitate efficient encapsulation and controlled release of bioactive compounds. Recent advances in the development of these systems against clinically relevant multidrug-resistant pathogens are analyzed, along with the antimicrobial mechanisms of EOs. Finally, the factors influencing encapsulation and release efficiency, as well as the main challenges and future perspectives for clinical translation, are discussed. Full article

In this paper, we consider a series of new compact A-π-D photoinitiators consisting of donor aromatic fragments (naphthalene, anthracene, phenanthrene, pyrene and perylene) and a strong acceptor tricyanoethylene group—aryltricyanoethylenes (ArTCNEs). Spectral, photophysical, and electrochemical characteristics of ArTCNEs are studied. One-photon (with LED@405 nm) and two-photon (λ = 780 nm, impulse duration of 100 fs) photopolymerization of PETA can be effectively initiated by ArTCNEs with the tertiary amine N,N-dimethylcyclohexylamine DMCHA and/or the iodonium salt diphenyliodonium chloride Iod. Based on results of experiments on photodegradation, photopolymerization and EPR spectroscopy, a photoinitiation mechanism of radical photopolymerization was proposed for two-component (AntTCNE/DMCHA) and three-component (AntTCNE/DMCHA/Iod) initiating systems. The composition containing PerTCNE/DMCHA as a photoinitiator demonstrated the best reactivity under two-photon nanolithography conditions: the polymerization threshold was 2 mW at a laser beam scanning speed of 100 μm/s, and the widest fabrication window of 11 mW was typical for it. As an example, 3D “cage” structures were fabricated using the AntTCNE-based composition, and the test structure resolution parameters, such as the minimum line width and the distance between lines of 80 and 400 nm, respectively, were achieved. MTT experiments with human dermal fibroblasts showed promising preliminary biocompatibility of the resulting polymers, which opens up possibilities for using the obtained materials in biological applications. Full article

Myocardial infarction (MI) is one of the prevalent cardiovascular diseases, which is caused by obstruction of one or more coronary arteries, leading to cardiac tissue ischemia and death. One of the main consequences of MI is heart failure, which is defined as dysfunction of the heart muscle to pump blood into peripheral organs. Cardiac patches have drawn a lot of interest as a potentially effective way to restore damaged cardiac tissue and enhance its functionality. They are polymer-based scaffolds designed to be implanted on the heart surface, and they have shown a significant therapeutic effect in the treatment of MI by improving cardiac function and providing mechanical support for the infarction site by the delivery of various bioactive substances or cells. Several biomaterials with specific mechanical and chemical characteristics have been widely used as a scaffold in the process of fabricating cardiac patches. In this study, we focus on the latest developments in the manufacturing of synthetic-polymer-based cardiac patches used to treat heart failure induced by myocardial infarction. We describe the mechanical and chemical characteristics of several synthetic polymers and highlight the main benefits and drawbacks of each type. An overview of the major challenges and the future development directions in the field of cardiac patches is also highlighted. Full article

Gene therapy relies on safe and efficient delivery systems, yet traditional viral vectors and synthetic polymers often fail to meet these requirements due to immunogenicity and biocompatibility concerns. This review highlights self-assembling short peptides as a highly programmable and biocompatible non-viral platform uniquely positioned to overcome these translational bottlenecks. To provide a comprehensive overview of next-generation gene delivery, we systematically trace the trajectory from fundamental chemistry to clinical applications. First, we elucidate the supramolecular interactions and mechanisms driving peptide–nucleic acid co-assembly. Second, we outline concrete design strategies, detailing how sequence engineering and environmental responsiveness dictate the formation of optimized nanomorphologies. Third, we critically analyze how these nanocarriers navigate critical physiological and intracellular barriers, with a specific focus on cellular uptake, endosomal escape, and cargo release. Finally, we demonstrate the platform’s versatility in emerging frontiers, particularly mRNA vaccines and CRISPR/Cas9 gene editing. We conclude by identifying current obstacles to clinical translation and proposing future directions centered on multifunctional integration and stimuli-responsive design. Full article

Treatment of postsurgical osteosarcoma remains one of the major challenges in orthopedic clinics. Conventional implants often fail to address complex pathological issues, including irregular bone defects, residual tumor cells, and delayed bone regeneration. Herein, this study reports a multifunctional shape-memory polyurethane (SMPU)/manganese dioxide (MnO₂) composite that provides adaptive support, antitumor activity, and osteogenic bioactivity. SMPU was synthesized by introducing 1,4-butanediol (BDO) and dimethylolpropionic acid (DMPA) as chain extenders at a specific ratio. Commercial MnO₂ nanoparticles were incorporated as both a photothermal agent and a bioactive component to achieve multifunctionality. As designed, a coordination system was formed between the polymer chains and MnO₂ nanoparticles within the composites. The influence of MnO₂ content was systematically investigated. Although increasing MnO₂ amounts improved photothermal and mechanical performance, excessive incorporation adversely affected the molecular structure and compromised the composite’s biocompatibility. By adjusting the MnO₂ content, the composites were demonstrated to possess robust mechanical performance, good shape-memory behavior, and controllable Mn²⁺ release. Additionally, the composites exhibited tunable photothermal performance under near-infrared (NIR) irradiation. Furthermore, in vitro studies confirmed that the composites containing 4 wt% MnO₂ could eliminate tumor cells via photothermal effects and promote the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Overall, the SMPU/MnO₂ composites had superior multifunction for treating irregular bone defects following bone tumor surgery. Full article

This research introduces a new hydroxyapatite-based composite, designed as a bone-implant scaffold—easy, quick, economical, and closely mimicking the structure of natural bone. Additive manufacture was used to print bioactive material to form a scaffold structure. Thus, during the experimental research, three different composite materials were made to examine both their mechanical and morphological properties. Numerical modeling was used to maximize and prove the mechanical and biological performance of the HA-polymer grafts. The obtained results indicated that incorporating HA and Mg particles into a polymeric matrix allows the structure to be used in tissue engineering. Best results were obtained using a structure, designed from PLA and PHA at 30%, PHB at 25%, Mg at 5%, and HA at 10%. The composite was distinguished by its lightness, strength, and biocompatibility, making it suitable for tissue engineering. Full article

An efficient bacteriophage delivery system needs to be developed to overcome the challenges associated with phage instability, rapid diffusion, and loss of infectivity at the infection site. Hydrogels have been found to be potential carriers. Hydrogels have emerged as promising carriers due to their biocompatibility, tunable physicochemical properties and capacity for controlled release. However, the molecular factors that regulate phage–hydrogel interactions remain poorly understood. In this study, we employed an in silico framework combining molecular docking, molecular dynamics (MD) simulations, MM/PBSA binding energy calculations, machine learning-based adhesion prediction, and diffusion modeling to explore phage–hydrogel interactions at the molecular level. Surface-exposed bacteriophage proteins, such as capsid and tail proteins, were evaluated against eight different hydrogel polymers. Binding site analysis revealed the presence of multiple solvent-accessible pockets that can interact with the polymer. Docking studies showed favorable and stable interactions, with hyaluronic acid showing strong binding affinity to multiple phage proteins (−5.5 to −5.7 kcal/mol) and GelMA showing high affinity to the capsid gp10 protein (−5.6 kcal/mol). The integrity of the structural complexes was further confirmed by 100 ns MD simulations, stable RMSD and RMSF trajectories, compact structural conformations, and favorable MM/PBSA binding energies. Machine learning classification successfully differentiated high- and low-adhesion systems and identified hydrogen bonding and electrostatic interactions as key determinants of sustained yet reversible phage retention. Collectively, our findings suggest that the hydrogels enriched with charged and polar functional groups can facilitate stable but non-destructive phage binding, enabling controlled and sustained release. This study provides mechanistic insights into rational hydrogel design for phage delivery systems and highlights the potential of high-throughput computational strategies to accelerate the development of optimized phage therapeutics. Full article

Cancer remains a major global health challenge, and the limitations of conventional therapies have intensified interest in treatment strategies that combine improved selectivity with reduced systemic toxicity. Photothermal therapy and photodynamic therapy have emerged as minimally invasive approaches capable of achieving spatiotemporally controlled tumour ablation. In this context, molybdenum disulfide (MoS₂), a transition metal dichalcogenide with strong near-infrared absorption, high photothermal conversion efficiency, and versatile surface chemistry, has gained increasing attention as a multifunctional platform for drug delivery and light-triggered cancer therapy. This review examines recent advances in engineered MoS₂ nanoplatforms for drug-enhanced cancer phototherapy, with emphasis on how surface design and therapeutic cargoes mechanistically amplify light-triggered tumour killing. Approaches such as polymer coatings, biomimetic membranes, targeting ligands, chemotherapeutic agents, nucleic acids, and photosensitisers have been explored to improve colloidal stability, tumour targeting, immune evasion, and stimulus-responsive drug release, while also adding complementary cytotoxic pathways such as chemotherapy, ROS generation, or gene silencing. Available in vitro and in vivo studies indicate that these systems generally exhibit favourable short-term biocompatibility under the tested conditions and can produce significant antitumour effects following irradiation. The review also discusses key biological barriers and translational challenges, including biodistribution, long-term safety, reproducibility, and regulatory considerations, highlighting opportunities for the development of clinically viable MoS₂-based phototherapeutic platforms. Full article

Konjac glucomannan (KGM) is a naturally derived polysaccharide known for its biocompatibility and gel-forming ability and has gained increasing attention in biomaterial and drug delivery research. However, the rheological behavior of KGM gels at clinically relevant concentrations for periodontal use has not been thoroughly investigated. In this study, KGM gels at 0.8%, 1.0%, and 1.2% (w/v) were prepared and evaluated using oscillatory and steady shear rheology. Rheological analysis revealed increased viscoelastic strength with increasing polymer content, with the 1.2% formulation showing the highest storage modulus, viscosity, and shear stress values across strain, frequency, and temperature ranges. All formulations demonstrated pronounced shear-thinning behavior and dominant elastic characteristics (G′ > G″), indicating stable gel network formation and favorable injectability. The viscoelastic profile remained stable near physiological temperature (37 °C), implying that the gel network can preserve mechanical integrity under intraoral conditions. Gamma irradiation at 15 kGy effectively achieved sterility without visible macroscopic instability, although a qualitative reduction in viscosity was observed. Collectively, these findings indicate that increasing KGM concentration improves mechanical robustness and viscoelastic stability, with the 1.2% gel demonstrating the most favorable rheological profile for potential localized periodontal application. Full article

Polymer-based biosensors have evolved from passive supports into active functional elements that dictate analytical performance in complex real-world samples. This critical review with meta-trend analysis examines 96 original research articles published between 2015 and 2025, evaluating how four polymer classes (conductive polymers, redox-mediator polymers, hydrogels, and molecularly imprinted polymers) address matrix effects in food, beverage, environmental and clinical applications. Electrochemical detection dominates (79% of studies), with conductive polymers enabling low-potential operation that excludes electroactive interference. Hydrogels achieve superior precision (RSD below 3%) in protein-rich matrices through biocompatible microenvironments that preserve enzyme kinetics. Molecularly imprinted polymers provide unmatched stability in harsh environments for trace-level detection of heavy metals and toxins, though delayed response times from slow analyte diffusion persist. Critical evaluation exposes validation deficits: 91% of studies omit limits of quantification, while approximately one-third lack reproducibility (33%) and precision (30%). The multi-matrix challenge, maintaining calibration across different hostile environments, remains the primary barrier to commercial deployment. Advanced architectures, including nanocapsulation, hierarchical nanocomposites, and microneedle-integrated systems, offer pathways to overcome limitations in fouling resistance and operational stability. Full article