Search Results (447)

Arthroscopic Superior Capsular Reconstruction has emerged as a promising surgical intervention for irreparable massive rotator cuff tears, aiming to restore glenohumeral joint stability and improve patient outcomes. A critical determinant of ASCR success is the selection of an appropriate graft material. This review explores the spectrum of grafts utilized in ASCR, including autografts, allografts, xenografts, and synthetic materials. The primary focus is on how the inherent biological properties of these grafts—such as cellularity, vascularity, immunogenicity, and extracellular matrix composition—profoundly influence the processes of graft healing, integration into host tissues, and ultimately, the rates of re-tearing. Autografts, particularly fascia lata, often demonstrate superior biological incorporation due to their viable cells and non-immunogenic nature, leading to high healing rates. Allografts, while offering advantages like reduced donor site morbidity, present biological challenges related to decellularization processes and slower remodeling, resulting in more variable healing outcomes. Xenografts face significant immunological hurdles, often leading to rejection and poor integration. Synthetic grafts provide an off-the-shelf option but interact with host tissue primarily as a scaffold, without true biological integration. Understanding the nuanced biological characteristics of each graft type is paramount for surgeons aiming to optimize healing environments and minimize re-tear rates, thereby enhancing the long-term efficacy of ASCR. Full article

In regenerative medicine, orthobiologics, particularly platelet-rich plasma (PRP), are widely used due to their ability to enhance natural tissue repair mechanisms. PRP contains a concentrated pool of growth factors and cytokines that enhance regeneration while also acting as a biomimetic scaffold, thereby optimizing the microenvironment for tissue healing. In bone tissue engineering, PRP is commonly combined with synthetic or natural biomaterials, as its fibrin matrix alone lacks sufficient mechanical stability. However, even such composite systems frequently exhibit limited osteoinductive capacity, necessitating further supplementation with bioactive components. This review evaluates the regenerative potential of PRP in bone defect healing when combined with osteoinductive agents in preclinical in vivo models. We present compelling experimental evidence supporting the efficacy of this combined therapeutic approach. Full article

Advancements in bioinks and three-dimensional (3D) printing and bioprinting have significantly advanced cardiovascular tissue engineering by enabling the fabrication of biomimetic cardiac and vascular constructs. Traditional 3D printing has contributed to the development of acellular scaffolds, vascular grafts, and patient-specific cardiovascular models that support surgical planning and biomedical applications. In contrast, 3D bioprinting has emerged as a transformative biofabrication technology that allows for the spatially controlled deposition of living cells and biomaterials to construct functional tissues in vitro. Bioinks—derived from natural biomaterials such as collagen and decellularized matrix, synthetic polymers such as polyethylene glycol (PEG) and polycaprolactone (PCL), or hybrid combinations—have been engineered to replicate extracellular environments while offering tunable mechanical properties. These formulations ensure biocompatibility, appropriate mechanical strength, and high printing fidelity, thereby maintaining cell viability, structural integrity, and precise architectural resolution in the printed constructs. Advanced bioprinting modalities, including extrusion-based bioprinting (such as the FRESH technique), droplet/inkjet bioprinting, digital light processing (DLP), two-photon polymerization (TPP), and melt electrowriting (MEW), enable the fabrication of complex cardiovascular structures such as vascular patches, ventricle-like heart pumps, and perfusable vascular networks, demonstrating the feasibility of constructing functional cardiac tissues in vitro. This review highlights the respective strengths of these technologies—for example, extrusion’s ability to print high-cell-density bioinks and MEW’s ultrafine fiber resolution—as well as their limitations, including shear-induced cell stress in extrusion and limited throughput in TPP. The integration of optimized bioink formulations with appropriate printing and bioprinting platforms has significantly enhanced the replication of native cardiac and vascular architectures, thereby advancing the functional maturation of engineered cardiovascular constructs. Full article

Biocompatible polymers have emerged as essential materials in medical 3D printing, enabling the fabrication of scaffolds, tissue constructs, drug delivery systems, and biosensors for applications in and on the human body. This review aims to provide a comprehensive overview of the current state of 3D-printable biocompatible polymers and their composites, with an emphasis on their processing methods, properties, and biomedical uses. The scope of this work includes both natural and synthetic biocompatible polymers, polymer–nanocomposite systems, and bioinks that do not require photo initiators. The relevant literature was critically examined to classify materials by type, evaluate their compatibility with major 3D printing techniques such as stereolithography, selective laser sintering, and fused deposition modeling, and assess their performance in various medical applications. Key findings highlight that reinforced polymer composites, tailored surface chemistries, and hybrid printing strategies significantly expand the range of functional, customizable, and affordable biomedical devices. This review concludes by discussing present-day applications and emerging trends, underscoring that 3D-printable biocompatible polymers are rapidly transitioning from research to clinical practice, offering transformative potential for patient-specific healthcare solutions. Full article

The global burden of cancer continues to grow, with bone cancer—though rare—posing serious challenges in terms of treatment and post-surgical reconstruction. Autologous bone grafting remains the gold standard, yet limitations such as donor site morbidity drive the search for alternative solutions. Tissue engineering, combining biomaterials and therapeutic agents, offers promising avenues. This study focuses on the development of multifunctional scaffolds based on collagen and hydroxyapatite obtained by the freeze-drying technique and incorporating both synthetic (doxorubicin) and natural (caffeic acid) compounds for osteosarcoma treatment. These scaffolds aim to combine tumor inhibition with bone regeneration, addressing the dual need for local drug delivery and structural repair in bone cancer therapy. The characterization of these composite materials revealed that a spongious structure with interconnected pores and a homogeneous pore distribution, with pore sizes between 20 and 250 μm suitable for osteoblasts infiltration. The Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis-differential scanning calorimetry (TG-DSC) and X-ray diffraction (XRD) analyses confirmed the formation of hydroxyapatite inside the collagen matrix. LDH and XTT assays confirmed that the antitumoral scaffolds possess great potential for osteosarcoma treatment, showing that after 3 days of culturing, the extracts containing doxorubicin-7A, both alone and in combination with caffeic acid-9A, significantly reduced the viability of cell lines to below 7% and 20%, respectively. Full article

Spinal cord injury (SCI) remains a devastating neurological condition characterized by loss of sensory, motor and autonomic function. Despite decades of research, no FDA-approved regenerative therapies currently exist to restore lost function following SCI. Schwann cells (SCs) support axon regeneration, remyelination, and neuroprotection after SCI, with their therapeutic potential validated in clinical trials demonstrating safe and feasible transplantation in humans. Although SC transplantation has shown promising results, challenges remain, including modest graft survival, limited host integration, and restricted migration that collectively contribute to constrain efficacy. To address these limitations, biomaterial scaffolds have been explored as synergistic platforms to enhance SC delivery and function. When combined with natural or synthetic biomaterials such as hydrogels, nanofiber scaffolds, or ECM-mimetic matrices, SCs demonstrate improved survival, retention, spatial distribution, and regenerative activity. The intrinsic regenerative properties of SCs, first demonstrated in models of peripheral nerve injury, make them particularly well-suited for neural repair of the central nervous system (CNS) compared to other cell types and their effectiveness can be enhanced synergistically when combined with biomaterials. These constructs not only provide structural support but also modulate the lesion microenvironment, enhance axon growth and improve SC integration with host tissue. Combinatorial approaches incorporating biomaterials with SCs are emerging as next-generation strategies to optimize repair for clinical translation. This review focuses on current progress in SC-based therapies combined with biomaterials, highlighting key preclinical advances, clinical translation efforts, and the path forward toward effective regenerative interventions for SCI. Full article

Vascularization remains a critical challenge in tissue engineering, limiting graft survival, integration, and clinical translation. Although bioprinting enables spatial control over vascular architectures, many existing approaches prioritize geometric precision over biological performance. Bioprinted vasculature can be understood as a dynamic and time-dependent system that requires tissue-specific maturation. Within this framework, hydrogel systems act as active microenvironments rather than passive scaffolds. Hydrogel platforms vary from natural matrices and synthetic polymers to bioinspired or stimuli-responsive systems, each offering tunable control over stiffness, degradation, and biochemical signaling needed for vascular maturation. The design requirements of large and small vessels differ in terms of mechanical demands, remodeling capacity, and host integration. A key limitation in current models is the absence of time-resolved evaluation, as critical processes such as lumen formation, pericyte recruitment, and flow-induced remodeling occur progressively and are not captured by static endpoints. Advancements in bioprinting technologies are evaluated based on their capacity to support hydrogel-mediated vascularization across varying length scales and structural complexities. A framework for functional assessment is proposed, and translational challenges related to immunogenicity, scalability, and regulatory requirements are discussed. Such integration of hydrogel-driven biological cues and bioprinting fidelity is critical to advancing vascularized constructs toward clinical translation. Full article

Background: Anaplastic lymphoma kinase (ALK) is a validated oncogenic driver in non-small cell lung cancer and other malignancies, making it a clinically relevant target for small-molecule inhibition. Methods: Here, we report a computational discovery pipeline integrating structure-based virtual screening, machine learning-guided prioritization, molecular dynamics simulations, and binding free energy analysis to identify potential ALK inhibitors from a natural product-derived subset of the ZINC20 database. We trained and benchmarked eleven machine learning models, including tree-based, kernel-based, linear, and neural architectures, on curated bioactivity datasets of ALK inhibitors to capture nuanced structure-activity relationships and prioritize candidates beyond conventional docking metrics. Results: Six compounds were shortlisted based on binding affinity, solubility, bioavailability, and synthetic accessibility. Molecular dynamics simulations over 100 ns revealed stable ligand engagement, with limited conformational fluctuations and consistent retention of the protein’s structural integrity. Key catalytic residues, including GLU105, MET107, and ASP178, displayed minimal fluctuation, while hydrogen bonding and residue interaction analyses confirmed persistent engagement across all ligand-bound complexes. Binding free energy estimates identified ZINC3870414 and ZINC8214398 as top-performing candidates, with ΔG_total values of –46.02 and –46.18 kcal/mol, respectively. Principal component and dynamic network analyses indicated that these compounds restrict conformational sampling and reorganize residue communication pathways, consistent with functional inhibition. Conclusions: These results highlight ZINC3870414 and ZINC8214398 as promising scaffolds for further optimization and support the utility of integrating machine learning with dynamic and network-based metrics in early-stage kinase inhibitor discovery. Full article

Two-dimensional cell culture systems lack the ability to replicate the complex, three-dimensional (3D) architecture and cellular microenvironments found in vivo. Multicellular spheroids (MCSs) present a promising alternative, with the ability to mimic native cell–cell and cell–matrix interactions and provide 3D architectures similar to in vivo conditions. These factors are critical for various biomedical applications, including cancer research, tissue engineering, and drug discovery and development. Polymeric materials such as hydrogels, solid scaffolds, and ultra-low attachment surfaces serve as versatile platforms for 3D cell culture, offering tailored biochemical and mechanical cues to support cellular organization. This review article focuses on the structure–property relationships of polymeric biomaterials that influence MCS formation, growth, and functionality. Specifically, we highlight their physicochemical properties and their influence on spheroid formation using key natural polymers, including collagen, hyaluronic acid, chitosan, and synthetic polymers like poly(lactic-co-glycolic acid) and poly(N-isopropylacrylamide) as examples. Despite recent advances, several challenges persist, including spheroid loss during media changes, limited viability or function in long-term cultures, and difficulties in scaling for high-throughput applications. Importantly, the development of MCS platforms also supports the 3R principle (Replacement, Reduction, and Refinement) by offering ethical and physiologically relevant alternatives to animal testing. This review emphasizes the need for innovative biomaterials and methodologies to overcome these limitations, ultimately advancing the utility of MCSs in biomedical research. Full article

Resistance of various bacterial pathogens to the activity of clinically approved drugs currently leads to serious infections, rapid spread of difficult-to-treat diseases, and even death. Taking the threats for human health in mind, researchers are focused on the isolation and characterization of novel natural products, including plant secondary metabolites. These molecules serve as inspiration and a suitable structural platform in the design and development of novel semi-synthetic and synthetic derivatives. All considered compounds have to be adequately evaluated in silico, in vitro, and in vivo using relevant approaches. The current review paper briefly focuses on the chemical and metabolic properties of resveratrol (1), as well as its oligomeric structures, viniferins, and viniferin-based molecules. The core scaffolds of these compounds contain so-called privileged structures, which are also present in many clinically approved drugs, indicating that those natural, properly substituted semi-synthetic, and synthetic molecules can provide a notably broad spectrum of beneficial pharmacological activities, including very impressive antimicrobial efficiency. Except for spectral verification of their structures, these compounds suffer from the determination or prediction of other structural and physicochemical characteristics. Therefore, the structure–activity relationships for specific dihydrodimeric and dimeric viniferins, their bioisosteres, and derivatives with notable efficacy in vitro, especially against chosen Gram-positive bacterial strains, are summarized. In addition, a set of descriptors related to their structural, physicochemical, pharmacokinetic, and toxicological properties is generated using various computational tools. The obtained values are compared to those of clinically approved drugs. The particular relationships between these in silico parameters are also explored. Full article

In recent years, significant progress has been made in breast reconstructive surgery, particularly with the use of three-dimensional (3D) disassemblable scaffolds. Reconstructive plastic surgery aimed at restoring the shape and size of the mammary gland offers medical, psychological, and social benefits. Using autologous tissues allows surgeons to recreate the appearance of the mammary gland and achieve tactile sensations similar to those of a healthy organ while minimizing the risks associated with implants; 3D disassemblable scaffolds are a promising solution that overcomes the limitations of traditional methods. These constructs offer the potential for patient-specific anatomical adaptation and can provide both temporary and long-term structural support for regenerating tissues. One of the most promising approaches in post-mastectomy breast reconstruction involves the use of autologous cellular and tissue components integrated into either synthetic scaffolds—such as polylactic acid (PLA), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), and polycaprolactone (PCL)—or naturally derived biopolymer-based matrices, including alginate, chitosan, hyaluronic acid derivatives, collagen, fibrin, gelatin, and silk fibroin. In this context, two complementary research directions are gaining increasing significance: (1) the development of novel hybrid biomaterials that combine the favorable characteristics of both synthetic and natural polymers while maintaining biocompatibility and biodegradability; and (2) the advancement of three-dimensional bioprinting technologies for the fabrication of patient-specific scaffolds capable of incorporating cellular therapies. Such therapies typically involve mesenchymal stromal cells (MSCs) and bioactive signaling molecules, such as growth factors, aimed at promoting angiogenesis, cellular proliferation, and lineage-specific differentiation. In our review, we analyze existing developments in this area and discuss the advantages and disadvantages of 3D disassemblable scaffolds for mammary gland reconstruction, as well as prospects for their further research and clinical use. Full article

In the rapidly evolving field of biomedical engineering, hydrogels have emerged as highly versatile biomaterials that bridge biology and technology through their high water content, exceptional biocompatibility, and tunable mechanical properties. This review provides an integrated overview of both natural and synthetic hydrogels, examining their structural properties, fabrication methods, and broad biomedical applications, including drug delivery systems, tissue engineering, wound healing, and regenerative medicine. Natural hydrogels derived from sources such as alginate, gelatin, and chitosan are highlighted for their biodegradability and biocompatibility, though often limited by poor mechanical strength and batch variability. Conversely, synthetic hydrogels offer precise control over physical and chemical characteristics via advanced polymer chemistry, enabling customization for specific biomedical functions, yet may present challenges related to bioactivity and degradability. The review also explores intelligent hydrogel systems with stimuli-responsive and bioactive functionalities, emphasizing their role in next-generation healthcare solutions. In modern medicine, temperature-, pH-, enzyme-, light-, electric field-, magnetic field-, and glucose-responsive hydrogels are among the most promising “smart materials”. Their ability to respond to biological signals makes them uniquely suited for next-generation therapeutics, from responsive drug systems to adaptive tissue scaffolds. Key challenges such as scalability, clinical translation, and regulatory approval are discussed, underscoring the need for interdisciplinary collaboration and continued innovation. Overall, this review fosters a comprehensive understanding of hydrogel technologies and their transformative potential in enhancing patient care through advanced, adaptable, and responsive biomaterial systems. Full article

Background/Objectives: A nanostructured membrane of polycaprolactone (a synthetic polymer) was synthesized using an electrospinning technique aiming to enhance its hydrophilicity and rate of degradation by surface modification via aminolysis. Since polycaprolactone nanofibrous films are naturally hydrophobic and with slow degradation, which restricts their use in biological systems, amino groups were added to the fiber surface using the aminolysis technique, greatly increasing the wettability of the membranes. Methods: Polycaprolactone nanofibrous membranes were synthesized via the electrospinning technique and surface modification by aminolysis. Trypsin, pepsin, and pancreatin were conjugated onto the aminolyzed PNF surface to further strengthen biocompatibility by enhancing the hydrophilicity, porosity, and biodegradation rate. SEM, FTIR, EDX, and liquid displacement method were performed to investigate proteolytic efficiency and morphological and physical characteristics such as hydrophilicity, porosity, and degradation rates. Results: Enzyme activity tests, which showed a zone of clearance, validated the successful enzyme conjugation and stability over a wide range of pH and temperatures. Scanning electron microscopy (SEM) confirms the smooth morphology of nanofibers with diameters ranging from 150 to 950 nm. Fourier transform infrared spectroscopy (FTIR) revealed the presence of O–H, C–O, C=O, C–N, C–H, and O–H functional groups. Energy-dispersive X-ray (EDX) elemental analysis indicates the presence of carbon, oxygen, and nitrogen atoms owing to the presence of peptide and amide bonds. The liquid displacement technique and contact angle proved that Pepsin-PNFs possess notably increased porosity (88.50% ± 0.31%) and hydrophilicity (57.6° ± 2.3 (L), 57.9° ± 2.5 (R)), respectively. Pancreatin-PNFs demonstrated enhanced enzyme activity and degradation rate on day 28 (34.61%). Conclusions: These enzyme-conjugated PNFs thus show improvements in physicochemical properties, making them ideal candidates for various biomedical applications. Future studies must aim for optimization of enzyme conjugation and in vitro and in vivo performance to investigate the versatility of these scaffolds. Full article

Metal chelation to bioactive small molecules is a well-established strategy to enhance the biological activity of the resulting complexes. Among the widely explored structural motifs, the combination of prominent metal centers with naturally inspired derivatives has attracted considerable attention. One such promising platform is the flavone scaffold, derived from flavonoids and studied since ancient times. Flavones are plant-derived compounds known for their diverse biological activities and health benefits. They exhibit significant structural variability, primarily through backbone modifications such as hydroxylation. Importantly, coordination of metal ions to hydroxylated flavone cores often improves their natural bioactivities, including anticancer and antimicrobial effects. In this review, we summarize transition metal complexes incorporating hydroxyflavone (OH–F) ligands reported over the past 15 years. We provide a concise overview of synthetic approaches and structural characterization, with a particular emphasis on coordination modes (e.g., maltol-type, acetylacetonate-type, catechol-type, and others). Furthermore, we discuss biological evaluation results, especially anticancer and antimicrobial studies, to highlight the therapeutic potential of these complexes. Finally, we suggest directions for the future development of metal-based agents bearing hydroxyflavone moieties through several critical points in terms of the accuracy, reproducibility, and relevance of biological studies involving metal-based compounds. Full article

Since the mid-19th century, researchers have explored the potential of bio-based polymeric materials for diverse applications, with particular promise in medicine. This review provides a focused and detailed examination of natural and synthetic biopolymers relevant to tissue engineering and biomedical applications. It emphasizes the structural diversity, functional characteristics, and processing strategies of major classes of biopolymers, including polysaccharides (e.g., hyaluronic acid, alginate, chitosan, bacterial cellulose) and proteins (e.g., collagen, silk fibroin, albumin), as well as synthetic biodegradable polymers such as polycaprolactone, polylactic acid, and polyhydroxybutyrate. The central aim of this manuscript is to elucidate how intrinsic properties—such as molecular weight, crystallinity, water retention, and bioactivity—affect the performance of biopolymers in biomedical contexts, particularly in drug delivery, wound healing, and scaffold-based tissue regeneration. This review also highlights recent advancements in polymer functionalization, composite formation, and fabrication techniques (e.g., electrospinning, bioprinting), which have expanded the application potential of these materials. By offering a comparative analysis of structure–property–function relationships across a diverse range of biopolymers, this review provides a comprehensive reference for selecting and engineering materials tailored to specific biomedical challenges. It also identifies key limitations, such as production scalability and mechanical performance, and suggests future directions for developing clinically viable and environmentally sustainable biomaterial platforms. Full article