Recent advances in regenerative biomaterials

Unlock the sustained therapeutic efficacy of mRNA

mRNA therapies have emerged as a transformative class of medicines, offering immense potential across a diverse array of applications. This progress has been particularly evident in the wake of the success of lipid nanoparticle (LNP)-based mRNA vaccines during the COVID-19 pandemic. As these applications expand, the demand for sustained protein production has become increasingly critical. However, conventional mRNA therapies face significant challenges, including inherent RNA instability and suboptimal expression efficiency, often requiring repeated dosing to maintain therapeutic efficacy over time. This review highlights recent advances in strategies to prolong the therapeutic efficacy of LNP-mRNA systems. We focus on preclinical and emerging approaches aimed at extending the period of protein translation by engineering both the mRNA molecule and the LNP delivery system. Sustained protein expression is a cornerstone of mRNA-based therapeutics, and addressing this challenge is vital for unlocking their therapeutic potential. We hope this review provides valuable insights to guide the development of optimized delivery platforms for LNP-mRNA therapeutics.

Tailoring hyaluronic acid hydrogels: Impact of cross-linker length and density on skin rejuvenation as injectable dermal fillers and their potential effects on the MAPK signaling pathway suppression

Hyaluronic acid (HA) hydrogels, obtained through cross-linking, provide a stable 3D environment that is important for controlled delivery and tissue engineering applications. Cross-linking density has a significant impact on the physicochemical properties of hydrogels, including their shape stability, mechanical stiffness and macromolecular diffusivity. However, often cross-linking chemistries require photoinitiator and catalyst that may be toxic and cause unwanted tissue response. Here, we prepared a series of HA hydrogel with varying cross-linker length and cross-linking density, which can be obtained by altering the feed ratio of three different cross-linkers from small molecules to macromolecules (e.g., 1,4-butanediol diglycidyl ether (BDDE), ferulic acid (FA), pluronic (PLU)), to ameliorate skin wrinkles in mice models. HA cross-linked with FA and PLU exhibited enzyme and temperature-dependent sol-to-gel phase transition, respectively, and the gels possess good injectability. In vitro test confirmed that HA hydrogels co-cultured with RAW 264.7 and HDF cells showed good biocompatibility. In particular, HA cross-linked with PLU stimulated the growth of HDF cells and HaCaT cells. HA cross-linked with PLU suppressed the expression levels of proteins involved in collagen degradation including mitogen-activated protein kinases (ERK, JNK, p38) and matrix metalloproteases (MMP-1, MMP-3, and MMP-9) resulting in increased deposition of Collagen I. The free-flowing sols of HA hydrogel precursors are subcutaneously injected into the back of BALB/c mice and form stable gels at the dermis layer and found to be non-toxic. More importantly, HA hydrogel cross-linked with PLU showed an enhanced anti-wrinkling effect in the wrinkled mice model. Thus, properties of HA hydrogels such as injectability, biocompatibility, and good anti-wrinkling effect altered through varying cross-linking density must be considered in the context of soft tissue engineering applications.

Effects of cell shape and nucleus shape on epithelial-mesenchymal transition revealed using chimeric micropatterns

Epithelial-mesenchymal transition (EMT) is a key phenotypic switch in cancer metastasis, leading to fatal consequences for patients. Under geometric constraints, the morphology of cancer cells changes in both cellular and subcellular levels, whose effects on EMT are, however, not fully understood. Herein, we designed and fabricated chimeric micropatterns of polystyrene (PS) with adhesion contrast to reveal the impacts of cell shapes and nuclear shapes on EMT in a decoupled way. Cell elongation was modulated via microwell aspect ratios (ARs), and nuclear deformation was generated through a micropillar array in the microwell. Human non-small cell lung cancer cells (A549) were cultured on the quasi-three dimensional micropatterned surfaces, and transforming growth factor-β1 (TGF-β1) was added to induce EMT. We found that chimeric micropatterns upregulated EMT with an increase of cellular AR and nuclear indentation under given TGF-β1. The subsequent assessment of the contractility and oriented assembly of microfilaments elucidated the key role of mechanotransduction in cell elongation and EMT, as proved by myosin inhibition, while it was obstructed by micropillars in the chimeric micropattern. Hence, the micropillar array possessed a nonmonotonic influence, enhancing the EMT of cells with AR of 1, but hindering the EMT with an impact more significant on microwells with large ARs due to the impeded cytoskeleton assembly. This fundamental research has illustrated the complex of cellular and subcellular geometries on cell behaviors including phenotype transition in cancer metastasis.

Unravelling the wound healing efficiency of 3D bioprinted alginate-gelatin-diethylaminoethyl cellulose-fibrinogen based skin construct in a rat's full thickness wound model

The skin, being the largest external organ, is highly vulnerable to injuries. To address the donor skin scarcity, tissue engineering and regenerative medicine have emerged as an alternative strategies to skin grafting over the past few decades. Recent advancements in 3D bioprinting technology however, have positioned it as a promising tool for constructing tissue that closely mimics in-vivo conditions, using a variety of biomaterials to meet the demands of tissue repair. An ideal 3D-printed tissue construct has the potential to provide an ideal tissue microenvironment, promoting wound healing while minimizing scar formation. In this study, we first optimized the bioink formulation by conducting toxicological evaluations, including skin irritation and skin sensitization tests, on two formulations of alginate-gelatin-DEAE cellulose, with and without fibrinogen. The addition of fibrinogen was found to reduce inflammation, making the fibrinogen-containing formulation the preferred choice for further studies. Further, we have analyzed the wound healing efficiency of 3D-printed dermal and epidermal-dermal constructs in rat full thickness wound model. Skin cells were isolated from rat tissue, and dermal, epidermal skin constructs were printed layer by layer using an alginate-gelatin-DEAE cellulose and fibrinogen-based bioink formulation, previously optimized in our laboratory. Full thickness excision wound was created and acellular, dermal and epidermal-dermal construct were implanted. Wound healing was analyzed by means of wound contraction, collagen synthesis, histopathological evaluation and gene expression analysis. Our results indicate that the epidermal-dermal construct promotes faster wound healing and enhanced angiogenesis compared to the dermal-alone and acellular constructs.

Injectable Hydrogel Loaded with Plasma-Rich Platelets Repairing Endometrial Injury and Remodeling Reproductive Function by Regulating PI3K/AKT Pathway

Infertility resulting from uterine damage has emerged as a significant challenge confronting the development of modern society. Existing therapeutic approaches frequently encounter limitations due to the intricate physical and physiological environment of uterus. Platelet-rich plasma (PRP), a concentrate of platelets enriched with various growth factors, has been used in uterine injury repair. However, the rapid release of activating factors from PRP limits its timeliness in therapeutic applications. This work involves the synthesis of a biodegradable hydrogel based on natural polysaccharides through dynamic Schiff base. The hydrogel demonstrates tissue adhesion, self-healing, and injectability. Furthermore, its internal porous architecture facilitates the loading and sustained release of PRP. In vitro experiments, the hydrogel loaded with RPR (HOHP) exhibits a significant enhancement in cell proliferation and migration and promotes vascular regeneration by upregulating the expression of VEGFA and further activating the intracellular phosphatidylinositol kinase (PI3K)/protein kinase B (AKT) pathway. In vivo experiments on uterine endometrial injury model, HOHP restores endometrial thickness and gland number, reduces collagen deposition, promotes angiogenesis to repair uterine damage and restore fertility, which provides reinforced endorsement for the clinical management of uterine injury and enhances fertility.

Retrospective perspectives and future trends in nanomedicine treatment: from single membranes to hybrid membranes

At present, various diseases seriously threaten human life and health, and the development of nanodrug delivery systems has brought about a turnaround for traditional drug treatments, with nanoparticles being precisely targeted to improve bioavailability. Surface modification of nanoparticles can prolong blood circulation time and enhance targeting ability. The application of cell membrane-coated nanoparticles further improves their biocompatibility and active targeting ability, providing new hope for the treatment of various diseases. Various types of cell membrane biomimetic nanoparticles have gradually attracted increasing attention due to their unique advantages. However, the pathological microenvironment of different diseases is complex and varied, and the single-cell membrane has several limitations because a single functional property cannot fully meet the requirements of disease treatment. Hybrid cell membranes integrate the advantages of multiple biological membranes and have become an emerging research hotspot. This review summarizes the application of cell membrane biomimetic nanoparticles in the treatment of various diseases and discusses the advantages, challenges and future development of biomimetic nanoparticles. We propose that the fusion of multiple membranes may be a reasonable trend in the future to provide some ideas and directions for the treatment of various diseases.

Recent Advances and Challenges for Biological Materials in Micro/Nanocarrier Synthesis for Bone Infection and Tissue Engineering

Roughly 1.71 billion people worldwide suffer from large bone abnormalities, which are the primary cause of disability. Traditional bone grafting procedures have several drawbacks that impair their therapeutic efficacy and restrict their use in clinical settings. A great deal of work has been done to create fresh, more potent strategies. Under these circumstances, a crucial technique for the regeneration of major lesions has emerged: bone tissue engineering (BTE). BTE involves the use of biomaterials that can imitate the natural design of bone. To yet, no biological material has been able to fully meet the parameters of the perfect implantable material, even though several varieties have been created and investigated for bone regeneration. Against this backdrop, researchers have focused a great deal of interest over the past few years on the subject of nanotechnology and the use of nanostructures in regenerative medicine. The ability to create nanoengineered particles that can overcome the current constraints in regenerative strategies─such as decreased cell proliferation and differentiation, insufficient mechanical strength in biological materials, and insufficient production of extrinsic factors required for effective osteogenesis has revolutionized the field of bone and tissue engineering. The effects of nanoparticles on cell characteristics and the application of biological materials for bone regeneration are the main topics of our review, which summarizes the most recent in vitro and in vivo research on the application of nanotechnology in the context of BTE.

In vivo dynamic visualization and evaluation of collagen degradation utilizing NIR-II fluorescence imaging in mice models

Collagen-based biomaterials are gaining prominence in tissue engineering, attributed to their remarkable biocompatibility, inherent biodegradability, and unparalleled capacity to facilitate tissue repair and regeneration. However, the ability to dynamically visualize and quantitatively assess collagen degradation in vivo remains a critical challenge, hindering the development of optimized biomaterials for clinical applications. To address this, a novel approach was developed to monitor the injury microenvironment by conjugating second near-infrared quantum dots with solid collagen. This live imaging system offered high-resolution, real-time tracking of collagen degradation both in vitro and in vivo, enabling a deeper understanding of the degradation behavior under various conditions. This system was applied to mouse models with different cartilage defects, including critical-sized defect (CSD), minor defect (Minor) and sham surgery (Sham) groups for a 28-day in vivo monitoring. Among them, the CSD group exhibited the fastest and most stable collagen degradation, indicating that the degradation rate was closely linked to the severity of the injury. Transcriptomic analysis further identified key signaling pathways that might drive rapid collagen degradation by promoting collagenase activity and tissue remodeling in cartilage defect conditions. In summary, our study provided valuable insights into the mechanisms of collagen degradation under different injury conditions, contributing to innovative strategies for designing collagen-related biomaterials in the future.

3D-printed Ti3C2/polycaprolactone composite scaffold with a DOPA-SDF1 surface modified for bone repair

Large bone defects are a major clinical challenge in bone reconstructive surgery. 3D printing is a powerful technology that enables the manufacture of custom tissue-engineered scaffolds for bone regeneration. Electrical stimulation (ES) is a treatment method for external bone defects that compensates for damaged internal electrical signals and stimulates cell proliferation and differentiation. In this study, we propose a simple, reliable, and versatile strategy to prepare multifunctional 3D printed scaffold combined with ES for bone defect therapy. Firstly, scaffolds composed of polycaprolactone (PCL) and Ti3C2 were prepared by 3D printing technology, and then a stromal cell derived factor 1 (SDF1) containing DOPA tag was loaded onto the scaffold surface. Ti3C2 was selected as the electrode component because of its excellent electrical conductivity. The selection of DOPA-modified SDF-1(DOPA-SDF1) can improve the material binding ability and exert long-term stem cell recruitment function. The results show that prepared 3D printed scaffold (DOPA-SDF1@PCL#Ti3C2) has good hydrophilicity, electrical conductivity, antibacterial property, biocompatibility and stem cell recruitment ability. Furthermore, the expression of osteogenic specific genes in scaffold surface cells was significantly increased when pulse ES (PES) treatment was applied. The results of tibial plateau defect repair experiment showed that DOPA-SDF1@PCL#Ti3C2 scaffold can significantly promote the formation of new bone and collagen fibres. When the DOPA-SDF1@PCL#Ti3C2 scaffold was used in combination with PES therapy, the bone defect regeneration rate was further improved. This kind of scaffold could provide a new strategy for promoting the healing of large bone injuries and could expand the application of adjuvant therapy such as PES.

Analytical methods in studying cell force sensing: principles, current technologies and perspectives

Mechanical stimulation plays a crucial role in numerous biological activities, including tissue development, regeneration and remodeling. Understanding how cells respond to their mechanical microenvironment is vital for investigating mechanotransduction with adequate spatial and temporal resolution. Cell force sensing-also known as mechanosensation or mechanotransduction-involves force transmission through the cytoskeleton and mechanochemical signaling. Insights into cell-extracellular matrix interactions and mechanotransduction are particularly relevant for guiding biomaterial design in tissue engineering. To establish a foundation for mechanical biomedicine, this review will provide a comprehensive overview of cell mechanotransduction mechanisms, including the structural components essential for effective mechanical responses, such as cytoskeletal elements, force-sensitive ion channels, membrane receptors and key signaling pathways. It will also discuss the clutch model in force transmission, the role of mechanotransduction in both physiology and pathological contexts, and biomechanics and biomaterial design. Additionally, we outline analytical approaches for characterizing forces at cellular and subcellular levels, discussing the advantages and limitations of each method to aid researchers in selecting appropriate techniques. Finally, we summarize recent advancements in cell force sensing and identify key challenges for future research. Overall, this review should contribute to biomedical engineering by supporting the design of biomaterials that integrate precise mechanical information.

Biodegradable polymeric occluder with controllable locking structure for closure of atrial septal defect via interventional treatment

Atrial septal defect (ASD) is one of the major congenital heart diseases, and transcatheter closure with a cardiac occluder is a modern method to treat ASD with the advantage of mini-invasiveness over traditional surgical closure. While current occlusion devices are mainly made of non-degradable nitinol with superelasticity, the permanent existence of a metal in vivo may trigger potential complications and especially has an adverse effect on the heart development for children. However, it is challenging to invent a superelasticity-free occluder that can be delivered through a catheter but firmly locked after being opened at the target site; it is also much desired for research and development to quickly assess the feasibility of a superelasticity-free occluder in vitro. Herein, a biodegradable poly(L-lactide) (PLLA) occluder composed of a braided PLLA frame as the skeleton and a nonwoven PLLA fabric as the flow-blocking membrane is developed, and a controllable locking structure is designed to enable firm closure for a device even without superelasticity. We also suggest and justify a series of in vitro methods to assess the efficacy of the biodegradable occluder, and the results confirm the reliability of locking, water-blocking, mechanical strength and degradability. It is found that the PLLA fabric with moderate fiber density is optimal for surface endothelialization. We also carry out biological assessments; significant endothelialization and alleviated inflammation response are observed after 6 months of subcutaneous implantation into rabbits. The porcine model illustrates that the biodegradable polymeric occluder can be successfully implanted into the atrial septum via transcatheter intervention; the follow-ups have confirmed the safety and efficacy of this biodegradable polymeric occluder with the controllable locking structure.

Effects of protein conformational transition accompanied with crosslinking density cues in silk fibroin hydrogels on the proliferation and chondrogenesis of encapsulated stem cells

Silk fibroin (SF) hydrogels possess excellent biocompatibility and biomimetic properties of the extracellular matrix. Among them, the mild chemical crosslinked SF hydrogels show great application potential in the fields of 3D cell culture and tissue repairing and thus have attracted widespread attention. However, the mobility of hydrophobic chain segments of SF molecules in these chemical crosslinked hydrogels can easily cause the molecules to undergo a self-assembly process from random coil to β-sheet conformation due to its lower energy state, thus inducing an inevitable conformational transition process. This process further leads to dynamic changes of important material features, such as the hydrogel pore size and mechanical properties, which can probably bring some non-negligible and unknown impacts on cell behaviors and their biomedical applications. In this study, a typical mild crosslinking system composed of horseradish peroxidase and hydrogen peroxide was chosen to prepare SF hydrogels. A feasible protein conformational transition rate controlling strategy based on hydrogel crosslinking density regulation was also proposed. Our results demonstrate that the lower the hydrogel crosslinking density, the faster the conformational transition rate. Subsequently, SF hydrogels with different conformational transition rates were successfully constructed to investigate the impact of the protein conformational transition rate accompanied with initial crosslinking density on the proliferation and chondrogenic differentiation of encapsulated stem cells. Results comprehensively illustrated that the conformational transition process could effectively regulate cell behavior. The hydrogel with an appropriate conformational transition rate obviously promoted the proliferation and chondrogenesis of encapsulated stem cells, while too fast or too slow transition processes slowed down these cell activities. These findings are hopefully to provide valuable guidance for the development and efficient usage of SF hydrogels in the fields of 3D cell culture and tissue engineering.

Composite Magnetic Filaments: From Fabrication to Magnetic Hyperthermia Application

The printing of composite magnetic filaments using additive manufacturing techniques has emerged as a promising approach for biomedical applications, particularly in bone tissue engineering and magnetic hyperthermia treatments. This study focuses on the synthesis of nanocomposite ferromagnetic filaments and the fabrication of bone tissue scaffolds with time-dependent properties. Three classes of polylactic acid-based biocompatible polymers-EasyFil, Tough and Premium-were combined with magnetite nanoparticles (Fe3O4) at concentrations of 10 wt% and 20 wt%. Extruded filaments were evaluated for microstructural integrity, printed dog-bone-shaped specimens were tested for elongation and mechanical properties, and cylindrical scaffolds were analyzed for magnetic hyperthermia performance. The tensile strength of EasyFil polylactic acid decreased from 1834 MPa (0 wt% Fe3O4) to 1130 MPa (-38%) at 20 wt% Fe3O4, while Premium polylactic acid showed a more moderate reduction from 1800 MPa to 1567 MPa (-13%). The elongation at break was reduced across all samples, with the highest decrease observed in EasyFil polylactic acid (from 42% to 26%, -38%). Magnetic hyperthermia performance, measured by the specific absorption rate, demonstrated that the 20 wt% Fe3O4 scaffolds achieved specific absorption rate values of 2-7.5 W/g, depending on polymer type. Our results show that by carefully selecting the right thermoplastic material, we can balance both mechanical integrity and thermal efficiency. Among the tested materials, Tough polylactic acid composites demonstrated the most promising potential for magnetic hyperthermia applications, providing optimal heating performance without significantly compromising scaffold strength. These findings offer critical insights into designing magnetic scaffolds optimized for tissue regeneration and hyperthermia-based therapies.

Nanoscale distribution of bioactive ligands on biomaterials regulates cell mechanosensing through translocation of actin into the nucleus

Cells respond to adhesive ligands such as arginine-glycine-aspartate (RGD) through integrins, which regulates cellular activities via influencing cytoskeleton assembly. Herein, we report that the nanoscale distribution of active ligands on biomaterials regulates cells through not only cytoplasmic tension but also nuclear tension. This is particularly related to translocation of actin into nucleus and highlighted in our interpretation of an "abnormal" phenomenon that large RGD nanospacing (>70 nm) disassembles integrin clusters, inhibits cell adhesion, but promotes osteogenic differentiation of mesenchymal stem cells. Our studies reveal that the unstable adhesion at the 150 nm RGD distance increases actin dynamics, resulting in the nuclear translocation of globular (G) actin. The compartment polymerization of more G-actins to filamentous actins in nucleus increases nuclear tension, facilitating transcription activity and releasing calcium ions from the endoplasmic reticulum. This noncanonical mechanotransduction process sheds insight into mechanotransduction pertinent to cell-material interactions.

Biomaterials for neuroengineering: applications and challenges

Neurological injuries and diseases are a leading cause of disability worldwide, underscoring the urgent need for effective therapies. Neural regaining and enhancement therapies are seen as the most promising strategies for restoring neural function, offering hope for individuals affected by these conditions. Despite their promise, the path from animal research to clinical application is fraught with challenges. Neuroengineering, particularly through the use of biomaterials, has emerged as a key field that is paving the way for innovative solutions to these challenges. It seeks to understand and treat neurological disorders, unravel the nature of consciousness, and explore the mechanisms of memory and the brain's relationship with behavior, offering solutions for neural tissue engineering, neural interfaces and targeted drug delivery systems. These biomaterials, including both natural and synthetic types, are designed to replicate the cellular environment of the brain, thereby facilitating neural repair. This review aims to provide a comprehensive overview for biomaterials in neuroengineering, highlighting their application in neural functional regaining and enhancement across both basic research and clinical practice. It covers recent developments in biomaterial-based products, including 2D to 3D bioprinted scaffolds for cell and organoid culture, brain-on-a-chip systems, biomimetic electrodes and brain-computer interfaces. It also explores artificial synapses and neural networks, discussing their applications in modeling neural microenvironments for repair and regeneration, neural modulation and manipulation and the integration of traditional Chinese medicine. This review serves as a comprehensive guide to the role of biomaterials in advancing neuroengineering solutions, providing insights into the ongoing efforts to bridge the gap between innovation and clinical application.

Evolution of branched peptides as novel biomaterials

Branched peptide-based materials draw inspiration from dendritic structures to emulate the complex architecture of native tissues, aiming to enhance the performance of biomaterials in medical applications. These innovative materials benefit from several key features: they exhibit slower degradation rates, greater stiffness, and the ability to self-assemble. These properties are crucial for maintaining the structural integrity and functionality of the materials over time. By integrating bioactive peptides and natural polymers within their branched frameworks, these materials offer modularity and tunability and can accommodate a range of mechanical properties, degradation rates, and biological functions making them suitable for biomedical applications, including drug delivery systems, wound healing scaffolds, and tissue engineering constructs. In drug delivery, these materials can be engineered to release therapeutic agents in a controlled manner, enhancing the efficacy and safety of treatments. In wound healing, they provide a supportive environment which promotes rapid and efficient tissue repair. The combination of biomimetic design and functional adaptability makes branched peptide-based materials a promising candidate for the development of next-generation biomaterials, paving the way for significant advancements in healthcare.

Advances in the application and research of biomaterials in promoting bone repair and regeneration through immune modulation

With the ongoing development of osteoimmunology, increasing evidence indicates that the local immune microenvironment plays a critical role in various stages of bone formation. Consequently, modulating the immune inflammatory response triggered by biomaterials to foster a more favorable immune microenvironment for bone regeneration has emerged as a novel strategy in bone tissue engineering. This review first examines the roles of various immune cells in bone tissue injury and repair. Then, the contributions of different biomaterials, including metals, bioceramics, and polymers, in promoting osteogenesis through immune regulation, as well as their future development directions, are discussed. Finally, various design strategies, such as modifying the physicochemical properties of biomaterials and integrating bioactive substances, to optimize material design and create an immune environment conducive to bone formation, are explored. In summary, this review comprehensively covers strategies and approaches for promoting bone tissue regeneration through immune modulation. It offers a thorough understanding of current research trends in biomaterial-based immune regulation, serving as a theoretical reference for the further development and clinical application of biomaterials in bone tissue engineering.

Effect of 3D-Printed Polycaprolactone Scaffold With Powdery/Smooth Micromorphology on Local Immune Environments

Selective laser sintering (SLS) has become a viable approach for producing biodegradable medical implants in various clinical applications. The resulting scaffolds typically exhibit a powdery microstructure, which may potentially impact the behavior of immune cells and immune responses in surrounding tissues. However, limited research has been conducted to understand the effect of surface morphology in SLS-fabricated scaffolds on local immune environments. This study aims to compare the effect of SLS-fabricated polycaprolactone (PCL) scaffolds with powdery and smooth surface morphologies on immune-related biological responses. Compared with those on the powdery micromorphology, RAW264.7 macrophages displayed greater dispersion and adopted a spread and elongated morphology on the scaffolds with smooth surface. The expression levels of arginase-1 and CD206 were found to be upregulated in macrophages adhering to the PCL scaffolds with smooth surface, accompanied by an augmented secretion of anti-inflammatory cytokines TGF-β and IL-10. Conversely, there was a decrease in the secretion of pro-inflammatory cytokines TNF-α and IL-12. When implanted in vivo, the SLS-derived scaffolds were completely covered by host tissues, Withing increased collagen deposition, indicating good histocompatibility. At 1-week post-implantation, there was a significantly higher presence of M2-type macrophages surrounding the scaffold compared to M1 macrophages in both groups. By 3 weeks post-implantation, the overall level of macrophages had decreased in both groups. However, a significant higher level of M1 macrophages were observed in the powdery scaffold group. At the same time, the number of neutrophils around the powder scaffold increased significantly, demonstrating long-term local inflammatory responses. The results suggested that post-treated scaffolds with smooth surfaces can effectively reduce local inflammation, making them more suitable for clinical implantation.

Synergistic effects of silica-enriched bioactive glass and tri-calcium phosphate nanocomposites on BMP2 gene expression for bone repair and regeneration applications

This study focuses on the development of biomaterials for bone regeneration highlighting 59S bioactive glass (59S BG), tri-calcium phosphate (TCP), and their 1:1 composite (59S BG/TCP). The synthesized materials demonstrated excellent properties for bone tissue engineering. Characterization revealed their thermal stability up to 900 °C, as confirmed by thermogravimetric analysis (TGA), while X-ray diffraction (XRD) identified calcium phosphate and silicate phases. Functional groups and chemical bonding were elucidated using Fourier transform infrared spectroscopy (FTIR). The composite exhibited remarkable mechanical properties, with a hardness of 167.87 HV and a strength of 680.52 MPa, indicating its suitability for load-bearing applications. Biological evaluations confirmed promising performance, with in-vitro bioactivity showing apatite formation and reduced XRD peak intensity. Biocompatibility assessments revealed hemolysis below 5 % and a 300 % cell proliferation rate by day three ensuring minimal cytotoxicity and favorable blood compatibility. Protein adsorption studies demonstrated strong interactions with bovine serum albumin (BSA) and lysozyme, supporting protein stability. Additionally, the composite showed enhanced osteogenic potential with elevated BMP2 gene expression indicating its capacity to promote robust bone regeneration. The synergy between 59S BG and TCP underscores the composite's potential as a promising material for effective bone repair and regeneration.

BioHastalex modified with silver nanolayers and heat treatment for antibacterial properties

Here, we present surface analysis and biocompatibility evaluation of novel composite material based on graphene oxide traded as BioHastalex. The pristine material's surface morphology and surface chemistry were examined by various analytical methods. The BioHastalex with a thin silver layer was subsequently heat treated and characterized, the impact on the material surface wettability and morphology was evaluated. Significant surface roughness and morphology changes were detected at the nanometer scale after heat treatment of Ag-sputtered BioHastalex. The deposition of a thin silver nanolayer had an outstanding effect on BioHastalex's antibacterial properties while still maintaining cell viability (MRC-5, HaCaT). The heat treatment of BioHastalex-Ag led to the formation of regular nanocluster arrays while affecting the Ag concentration on the very surface. The decrease in silver concentration was connected with the length of heat treatment; cells growing on such samples exhibited good viability, and the antibacterial properties were weaker than simply sputtered BioHastalex.

Advancements in Cancer Treatment: Harnessing the Synergistic Potential of Graphene-Based Nanomaterials in Combination Therapy

Combination therapy, which involves using multiple therapeutic modalities simultaneously or sequentially, has become a cornerstone of modern cancer treatment. Graphene-based nanomaterials (GBNs) have emerged as versatile platforms for drug delivery, gene therapy, and photothermal therapy. These materials enable a synergistic approach, improving the efficacy of treatments while reducing side effects. This review explores the roles of graphene, graphene oxide (GO), and graphene quantum dots (GQDs) in combination therapies and highlights their potential to enhance immunotherapy and targeted cancer therapies. The large surface area and high drug-loading capacity of graphene facilitate the codelivery of multiple therapeutic agents, promoting targeted and sustained release. GQDs, with their unique optical properties, offer real-time imaging capabilities, adding another layer of precision to treatment. However, challenges such as biocompatibility, long-term toxicity, and scalability need to be addressed to ensure clinical safety. Preclinical studies show promising results for GBNs, suggesting their potential to revolutionize cancer treatment through innovative combination therapies.

Aerogels Based on Chitosan and Collagen Modified with Fe2O3 and Fe3O4 Nanoparticles: Fabrication and Characterization

The necessity to mitigate the intrinsic issues associated with tissue or organ transplants, in order to address the rising prevalence of diseases attributable to increased life expectancy, provides a rationale for the pursuit of innovation in the field of biomaterials. Specifically, biopolymeric aerogels represent a significant advancement in the field of tissue engineering, offering a promising solution for the formation of temporary porous matrices that can replace damaged tissues. However, the functional characteristics of these materials are inadequate, necessitating the implementation of matrix reinforcement methods to enhance their performance. In this study, chemical and green iron oxide nanoparticles, previously synthesized and documented in existing research, were incorporated into hybrid aerogels combining collagen (C) and chitosan (CH). The characterization of these aerogels was conducted through rheological, microstructural, and functional analyses. The results demonstrate that the incorporation of iron oxide nanoparticles has a significant influence on the properties of the aerogels fabricated with them. In particular, the incorporation of these nanoparticles has been observed to modify the mechanical properties, with an increase in strength and porosity that may support cell proliferation.

Lockd Enhances Mandibular Mesenchymal Stem Cell Proliferation While Inhibiting Osteogenic Capability via Binding With SUZ12 in the Inflammatory Microenvironment

AIM

To investigate the role of lncRNA Lockd in mandibular mesenchymal stem cell (M-MSC) proliferation and osteogenic capability in the inflammatory microenvironment, focusing on its interaction with SUZ12.

MATERIALS AND METHODS

Using lncR Lockd knockdown/overexpression cell models and a murine periodontitis model, we explored Lockd's effects on M-MSC proliferation and osteogenic capability in the inflammatory microenvironment. Predictions from multiple databases and a series of rescue experiments revealed the regulatory role of the Lockd/SUZ12 signalling axis of M-MSC in the inflammatory microenvironment.

RESULTS

Lockd was found to stimulate M-MSC proliferation but impair osteogenic differentiation. The in vitro studies suggested that the activation of Lockd negatively inhibited the osteogenic differentiation process and may ultimately impact bone formation in periodontitis. Mechanistically, it was elucidated that Lockd interacts with SUZ12, a core component of the polycomb repressive complex 2 (PRC2), and may affect the PRC2 complex's role in osteogenic gene expression.

CONCLUSIONS

Lockd boosts the proliferation of M-MSCs but inhibits their osteogenic differentiation by interacting with SUZ12, potentially inhibiting osteogenic capability in the inflammatory microenvironment.

A sterilization method for human decellularized vaginal matrices

Vaginal reconstruction is necessary for various congenital and acquired conditions, including vaginal aplasia, trauma, tumors, and gender incongruency. Current surgical and non-surgical treatments often result in significant complications. Decellularized vaginal matrices (DVMs) from human tissue offer a promising alternative, but require effective sterilization to ensure safety and functionality. This study aimed to develop a sterilization method for decellularized human vaginal wall scaffolds. Based on our previously implemented decellularization technique with minor modifications, we designed and examined three sterilization methods consisting of (i) chemical decellularization, (ii) decellularization with additional peracetic acid/hydrogen peroxide (PAA/H2O2); (iii) decellularization with antibiotic and antimycotic (AAE) based treatment. Sterilization efficacy was evaluated through controlled contamination with common vaginal microbes and sterility testing subsequent to each sterilization method. The extracellular matrix (ECM) structure was assessed via histological staining. Decellularization alone reduced some added bacterial contaminants but did not achieve complete sterilization. PAA/H2O2-sterilization resulted in severe ECM damage, rendering it unsuitable. The AAE-treatment demonstrated effective sterilization without compromising the ECM structure. Combined decellularization and AAE-based treatment forms a viable sterilization method for human vaginal wall tissue, maintaining ECM integrity and achieving effective micro-organism elimination. This method holds potential for clinical application in vaginal transplantation.

Biomimetic Natural Biomaterial Nanocomposite Scaffolds: A Rising Prospect for Bone Replacement

Biomimetic natural biomaterial (BNBM) nanocomposite scaffolds for bone replacement can reduce the rate of implant failure and the associated risks of post-surgical complications for patients. Traditional bone implants, like allografts, and autografts, have limitations, such as donor site morbidity and potential patient inflammation. Over two million bone transplant procedures are performed yearly, and success varies depending on the material used. This emphasizes the importance of developing new biomaterials for bone replacement. Innovative BNBM nanocomposites for modern bone fabrication can promote the colonization of the desired cellular components and provide the necessary mechanical properties. Recent studies have highlighted the advantages of BNBM nanocomposites for bone replacement; therefore, this review focuses on the application of cellulose, chitosan, alginates, collagen, hyaluronic acid, and synthetic polymers enhanced with nanoparticles for the fabrication of nanocomposite scaffolds used in bone regeneration and replacement. This work outlines the most up-to-date overview and perspectives of selected promising BNBM nanocomposites for bone replacement that could be used for scaffold fabrication and replace other biomorphic materials such as metallics, ceramics, and synthetic polymers in the future. In summary, the concluding remarks highlight the advantages and disadvantages of BNBM nanocomposites, prospects, and future directions for bone tissue regeneration and replacement.

Exploring the frontiers: The potential and challenges of bioactive scaffolds in osteosarcoma treatment and bone regeneration

The standard treatment for osteosarcoma combines surgery with chemotherapy, yet it is fraught with challenges such as postoperative tumor recurrence and chemotherapy-induced side effects. Additionally, bone defects after surgery often surpass the body's regenerative ability, affecting patient recovery. Bioengineering offers a novel approach through the use of bioactive scaffolds crafted from metals, ceramics, and hydrogels for bone defect repair. However, these scaffolds are typically devoid of antitumor properties, necessitating the integration of therapeutic agents. The development of a multifunctional therapeutic platform incorporating chemotherapeutic drugs, photothermal agents (PTAs), photosensitizers (PIs), sound sensitizers (SSs), magnetic thermotherapeutic agents (MTAs), and naturally occurring antitumor compounds addresses this limitation. This platform is engineered to target osteosarcoma cells while also facilitating bone tissue repair and regeneration. This review synthesizes recent advancements in integrated bioactive scaffolds (IBSs), underscoring their dual role in combating osteosarcoma and enhancing bone regeneration. We also examine the current limitations of IBSs and propose future research trajectories to overcome these hurdles.

Decellularization of fish tissues for tissue engineering and regenerative medicine applications

Decellularization is the process of obtaining acellular tissues with low immunogenic cellular components from animals or plants while maximizing the retention of the native extracellular matrix structure, mechanical integrity and bioactivity. The decellularized tissue obtained through the tissue decellularization technique retains the structure and bioactive components of its native tissue; it not only exhibits comparatively strong mechanical properties, low immunogenicity and good biocompatibility but also stimulates in situ neovascularization at the implantation site and regulates the polarization process of recruited macrophages, thereby promoting the regeneration of damaged tissue. Consequently, many commercial products have been developed as promising therapeutic strategies for the treatment of different tissue defects and lesions, such as wounds, dura, bone and cartilage defects, nerve injuries, myocardial infarction, urethral strictures, corneal blindness and other orthopedic applications. Recently, there has been a growing interest in the decellularization of fish tissues because of the abundance of sources, less religious constraints and risks of zoonosis transmission between mammals. In this review, we provide a complete overview of the state-of-the-art decellularization of fish tissues, including the organs and methods used to prepare acellular tissues. We enumerated common decellularized fish tissues from various fish organs, such as skin, scale, bladder, cartilage, heart and brain, and elaborated their different processing methods and tissue engineering applications. Furthermore, we presented the perspectives of (i) the future development direction of fish tissue decellularization technology, (ii) expanding the sources of decellularized tissue and (iii) innovating decellularized tissue bio-inks for 3D bioprinting to unleash the great potential of decellularized tissue in tissue engineering and regenerative medicine applications.

Integrin Subtypes and Lamellipodia Mediate Spatial Sensing of RGD Ligands during Cell Adhesion

Understanding how the spatial distribution of adhesive ligands regulates cell behavior is crucial for designing biomaterials. This study investigates how precisely controlled ligand spacing affects cell spreading and integrin subtype engagement. Using engineered polyacrylamide hydrogels with gold nanoparticle arrays, we explored the impact of RGD ligand spacings (30 and 150 nm) on human mesenchymal stromal cells. Cells exhibited distinct morphological behaviors: smaller spacings promoted larger spreading areas, while larger spacings resulted in elongated shapes with reduced spreading. Mechanistically, we found that the α5β1 integrin, not the αvβ3 integrin, played a central role in mediating these responses, alongside lamellipodia formation. Our findings provide critical insights into the spatial sensing of ligands, highlighting the influence of ligand spacing on cellular mechanotransduction and integrin-specific responses. This work advances the understanding of cell-material interactions and offers potential strategies for designing biomaterials to guide cell behavior in tissue engineering.

Advancements in nanohydroxyapatite: synthesis, biomedical applications and composite developments

Nanohydroxyapatite (nHA) is distinguished by its exceptional biocompatibility, bioactivity and biodegradability, qualities attributed to its similarity to the mineral component of human bone. This review discusses the synthesis techniques of nHA, highlighting how these methods shape its physicochemical attributes and, in turn, its utility in biomedical applications. The versatility of nHA is further enhanced by doping with biologically significant ions like magnesium or zinc, which can improve its bioactivity and confer therapeutic properties. Notably, nHA-based composites, incorporating metal, polymeric and bioceramic scaffolds, exhibit enhanced osteoconductivity and osteoinductivity. In orthopedic field, nHA and its composites serve effectively as bone graft substitutes, showing exceptional osteointegration and vascularization capabilities. In dentistry, these materials contribute to enamel remineralization, mitigate tooth sensitivity and are employed in surface modification of dental implants. For cancer therapy, nHA composites offer a promising strategy to inhibit tumor growth while sparing healthy tissues. Furthermore, nHA-based composites are emerging as sophisticated platforms with high surface ratio for the delivery of drugs and bioactive substances, gradually releasing therapeutic agents for progressive treatment benefits. Overall, this review delineates the synthesis, modifications and applications of nHA in various biomedical fields, shed light on the future advancements in biomaterials research.

Recent Advances in Regenerative Endodontics: A Review of Current Techniques and Future Directions

Regenerative endodontics is a rapidly evolving discipline focused on biologically restoring the pulp-dentin complex to revive vitality in non-vital teeth. Unlike traditional endodontic therapies that rely on inert materials to preserve structure, regenerative techniques aim to re-establish natural structure and function by harnessing advancements in tissue engineering. This narrative review examines recent progress in stem cell applications, scaffold development, signaling molecules, and clinical protocols that contribute to successful regenerative outcomes. Advances in stem cell sources, biomimetic scaffolds, and growth factor delivery systems have shown promising results, though challenges such as variability in outcomes and the need for standardized clinical protocols remain. This review also highlights future directions, including gene therapy and three-dimensional bioprinting, which hold the potential to overcome current limitations and pave the way for effective and reliable biologically restorative dental treatments.

Simultaneous co-assembly of collagen and glycosaminoglycans to build a biomimetic extracellular matrix for bone regeneration

Glycosaminoglycans (GAGs), also known as shape modules, are considered junctions that help define the shape of collagen matrix and further promote mineralization during osteogenesis. Many attempts have been made to immobilize GAGs on assembled collagen to modify the latter's surface state. However, it remains unclear how GAGs spontaneously identify collagen molecules during fibrillogenesis in vivo. Understanding the relationship between GAGs and collagen from both the bone physiology and materials science perspectives is of fundamental interest. Here, we introduced hyaluronic acid (HA, a main member of GAGs) during collagen self-assembly, in a process called modification cooperating with self-assembly (MCS). The molecular docking and morphological studies revealed that HA can help define collagen monomer deposition and thus promote fibrillogenesis through steric hindrance or by directly forming hydrogen bonds. Meanwhile, HA acts as a templating chaperone (TC) to increase the local mineral concentration within intrafibrillar channels but does not initiate nucleation, thus improving the crystallinity of formed apatite. The scaffolds synthesized through MCS model significantly improved the physicochemical stability and mechanical strength of collagen-based scaffolds. The optimized scaffolds promoted in-situ osteogenesis by stimulating the osteogenic differentiation of bone mesenchymal stem cells, either in an osteogenic medium, or after implantation into critical calvarial defects. This study provides novel insights towards evolving engineering scaffolds from inert supports to functional substitutes.

Injectable drug-loaded thermosensitive hydrogel delivery system for protecting retina ganglion cells in traumatic optic neuropathy

Currently, generalized therapy for traumatic optic neuropathy (TON) is lacking. Various strategies have been developed to protect and regenerate retinal ganglion cells (RGCs) after TON. Intravitreal injection of supplements has been approved as a promising approach, although serious concerns, such as low delivery efficacy and pain due to frequent injections, remain. In this study, we tested an injectable thermosensitive hydrogel drug delivery system engineered to deliver ciliary neurotrophic factor (CNTF) and triamcinolone acetonide (TA). The results of rheological studies showed that the prepared drug-loaded hydrogel possessed a suitable mechanical modulus of ∼300 Pa, consistent with that of vitreum. The hydrogel exhibited thermosensitive with sustained drug release performance. In vitro co-culture of the CNTF-loaded hydrogel system with primary RGCs also induced significant axon regeneration, with 38.5% increase in neurite length, indicating the regenerative response of the thermosensitive hydrogel drug delivery system. A Sprague-Dawley rat optic nerve crush model was constructed and applied to determine the neuroprotective and regenerative capacities of the system. The results demonstrated that a single intravitreal injection of the drug-loaded hydrogel (PLGA-PEG-PLGA + TA or PLGA-PEG-PLGA + CNTF) significantly increased RGC survival at both 14 and 28 days. The RGC survival rate was 31.05 ± 1.41% for the drug-loaded hydrogel system (the control group was 16.79 ± 1.50%) at Day 28. These findings suggest that the injectable drug-loaded thermosensitive hydrogel delivery system is a promising therapeutic tool for treating optic nerve degeneration.

Nanomaterials based on hollow gold nanospheres for cancer therapy

Gold nanoparticles have recently been exploited as versatile nanocarriers in diagnostic and therapeutic drug delivery for cancer nanomedicine, owing to their biocompatibility, low biotoxicity, surface modifiability and plasma optical properties. A variety of gold nanoparticles have emerged for drug delivery, mainly including gold nanorods, gold nanocages, gold nanostars, gold solid nanospheres and hollow gold nanospheres (HGNs). Among these, HGNs have widely been studied for their higher photothermal conversion efficiency, wider spectral absorption range and stronger surface-enhanced Raman scattering compared with solid gold nanospheres. Therefore, nowadays, researchers prefer to use HGNs to other metal nanocarriers, which can not only play the role of controlled-release drugs but also act as photothermal agents for tumor therapy and diagnosis, due to their properties of surface modification. Combined with the Au-S bond on the surface of HGNs, the targeted preparation is loaded to achieve precise drug delivery. With the assistance of the photothermal characteristics of HGNs themselves, the efficacy of loaded drugs in HGNs is enhanced. In addition, HGNs also have vital values in the field of bioimaging, which serve as photothermal imaging agents and Raman scattering-guided preparations due to their surface-enhanced Raman scattering properties to assist researchers in achieving the purpose of tumor diagnosis. In this review, we summarize the synthesis methods of HGNs and the recent application of HGNs-based nanomaterials in the field of cancer diagnosis and therapy. In addition, the issues to be addressed were pointed out for a bright prospect of HGNs-based nanomaterials.

Deciphering Immunotoxicity in Animal-Derived Biomaterials: A Genomic and Bioinformatics Approach

Immunotoxicity evaluation has been crucial in preclinical testing for implantable animal-derived biomaterials due to their prolonged contact with the human body, which requires stringent safety assessments. By creating experimental models with varying levels of immunotoxicity, this study reveals the decisive role of decellularization treatment in diminishing the immunogenicity of materials, thus ensuring clinical safety. Employing cutting-edge differential gene expression analysis, the research not only accurately quantifies gene expression alterations in immune responses but also, through pathway enrichment analysis, identifies gene networks associated with oncogenesis. This offers novel insights into the mechanisms of immune responses following biomaterial implantation. Additionally, the study highlights the importance of developing highly sensitive immunotoxicity testing methods and validates the efficacy of high-throughput sequencing and bioinformatics tools in assessing biomaterial safety, providing robust scientific support for future preclinical evaluations.

A facile nanopattern modification of silk fibroin electrospun scaffold and the corresponding impact on cell proliferation and osteogenesis

As a well-known natural protein biomaterial, silk fibroin (SF) has shown broad application prospects in typical biomedical fields. However, the mostly used SF from Bombyx mori silkworm lacks specific cell adhesion sites and other bioactive peptide sequences, and there is still significant room for further improvement of their biological functions. Therefore, it is crucial to develop a facile and effective modification strategy for this widely researched biomaterial. In this study, the SF electrospun scaffold has been chosen as a typical SF biomaterial, and air plasma etching has been adopted as a facile nanopattern modification strategy to promote its biological functions. Results demonstrated that the plasma etching could feasibly and effectively create nano-island-like patterns on the complex surface of SF scaffolds, and the detailed nanopattern features could be easily regulated by adjusting the etching time. In addition, the mesenchymal stem cell responses have illustrated that the nanopattern modification could significantly regulate corresponding cell behaviors. Compared with the non-etched scaffold, the 10 min-etched scaffolds (10E scaffold) significantly promoted stem cell proliferation and osteogenic differentiation. Moreover, 10E scaffold has also been confirmed to effectively accelerate vascularization and ectopic osteogenesis in vivo using a rat subcutaneous implantation model. However, the mentioned promoting effects would be weakened or even counteracted with the increase of etching time. In conclusion, this facile modification strategy demonstrated great application potential for promoting cell proliferation and differentiation. Thus, it provided useful guidance to develop excellent SF-based scaffolds suitable for bone and other tissue engineering.

Recent advances in plant-derived polysaccharide scaffolds in tissue engineering: A review

As a natural three-dimensional biopolymer, decellularized plant-derived scaffolds usually comprise various polysaccharides, mostly cellulose, pectin, and hemicellulose. They are characterized by natural biocompatibility and porous structures. The emergence of decellularized purified polysaccharide scaffolds provides an attractive method to overcome the challenges associated with nutrient delivery and biocompatibility, as they serve as optimal non-immune environments for stem cell adhesion and proliferation. To date, limited corresponding literature is available to systemically summarize the development and potential of these scaffolds in tissue engineering. Therefore, the current review summarized the biomimetic properties of plant-derived polysaccharide scaffolds and the latest progress in tissue engineering applications. This review first discusses the advantages of decellularized plant-derived polysaccharide scaffolds by briefly introducing their features and current limitations in clinical applications. Subsequently, the latest progress in emerging applications of regenerative biomaterials is reviewed, followed by a discussion of the studies on the interactions of biomaterials with cells and tissues. Finally, challenges in obtaining reliable scaffolds and possible future directions are discussed.

Soft material drilling: A thermo-mechanical analysis of polyurethane foam for biomimetic bone scaffolds and optimization of process parameters using Taguchi method

Drilling is a widely employed technique in machining processes, crucial for efficient material removal. However, when applied to living tissues, its invasiveness must be carefully considered. This study investigates drilling processes on polyurethane foam blocks mimicking human bone mechanical properties. Various drill bit types (118° twist, 135° twist, spherical, and conical), drilling speeds (1000-1600 rpm), and feed rates (20-80 mm/min) were examined to assess temperature elevation during drilling. The Taguchi method facilitated systematic experiment design and optimization. Signal-to-noise (S/N) ratio and analysis of variance (ANOVA) identified significant drilling parameters affecting temperature rise. Validation was conducted through confirmation testing. Results indicate that standard twist drill bits with smaller point angles, lower drilling speeds, and higher feed rates effectively minimize temperature elevation during drilling.

Maglev-fabricated long and biodegradable stent for interventional treatment of peripheral vessels

While chronic limb-threatening ischemia is a serious peripheral artery disease, the lack of an appropriate stent significantly limits the potential of interventional treatment. In spite of much progress in coronary stents, little is towards peripheral stents, which are expected to be both long and biodegradable and thus require a breakthrough in core techniques. Herein, we develop a long and biodegradable stent with a length of up to 118 mm based on a metal-polymer composite material. To achieve a well-prepared homogeneous coating on a long stent during ultrasonic spraying, a magnetic levitation is employed. In vivo degradation of the stent is investigated in rabbit abdominal aorta/iliac arteries, and its preclinical safety is evaluated in canine infrapopliteal arteries. First-in-man implantation of the stent is carried out in the below-the-knee artery. The 13 months' follow-ups demonstrate the feasibility of the long and biodegradable stent in clinical applications.

Autophagy inhibition mediated via an injectable and NO-releasing hydrogel for amplifying the antitumor efficacy of mild magnetic hyperthermia

While mild hyperthermia holds great potential in the treatment of solid tumors, the thermal stress-triggered self-repairing autophagy significantly compromises its efficacy. To circumvent this obstacle, an injectable hydrogel (NO-Gel) composed of thermosensitive poly(ethylene glycol)-polypeptide copolymers modified with abundant NO donors on their side chains is developed. Meanwhile, ferrimagnetic Zn0.5Fe2.5O4 magnetic nanoparticles (MNPs) with high magnetic-heat conversion efficiency are synthesized and loaded into NO-Gel to obtain MNPs@NO-Gel. The MNPs@NO-Gel system exhibits a sol-gel transition upon heating, and has the ability to perform multiple magnetic hyperthermia therapy (MHT) after only one administration due to the even distribution and strong immobilization of MNPs in NO-Gel. NO can be continuously liberated from NO-Gel and this process is markedly accelerated by MHT. Additionally, MNPs@NO-Gel maintains its integrity in vivo for over one month and the released MNPs are metabolized by the spleen. After a single administration of MNPs@NO-Gel at the tumor site, three mild MHT treatments with similar effects are fulfilled, and the sufficient supply of NO effectively inhibits MHT-induced autophagic flux via blocking the formation of autophagosomes and synchronously destroying lysosomes, thereby substantially boosting the efficacy of mild MHT. As a consequence, CT-26 colon tumors are completely eliminated without causing severe side-effects.

Enhancing the immunomodulatory osteogenic properties of Ti-Mg alloy by Mg2+-containing nanostructures

Facilitating an appropriate immune response is crucial for promoting bone tissue regeneration upon biomaterial implantation. In this study, the Mg2+-containing nanostructures on the surface of Ti-1.25Mg alloy were prepared by a one-step hydrothermal reaction method via regulating pH value to enhance the immunomodulatory osteogenic properties of Ti-Mg alloys. In neutral (HT7) or alkaline (HT9) hydrothermal treatment (HT) solution, the size of MgTiO3 nanostructures formed on the surface of Ti-1.25Mg alloy is smaller than that in acidic HT solution (HT5), and lamellar Mg(OH)2 nanostructures are found in HT7 and HT9. In addition, the sample surface has a lower roughness and higher wettability with increasing pH value. The Mg2+-containing nanostructures on the Ti-1.25Mg alloy inhibited inflammatory response by promoting the polarization of M2 macrophages, thereby promoting osteogenesis in vitro. The micro-CT and histological assessment proved that the regeneration of bone defect was faster in HT7 than the Ti-1.25Mg in vivo. Mechanically, Mg2+-containing nanostructures can mediate the immune response of macrophages via upregulating integrins α5β1 and inhibiting Toll-like receptors (TLR-4), subsequently inhibiting the NF-κB signaling pathway. Overall, osteoimmunity-regulating Mg2+-containing nanostructures on Ti-1.25Mg present a promising biomaterial for bone repair.

Constructing a highly efficient multifunctional carbon quantum dot platform for the treatment of infectious wounds

Antibiotic resistance poses a huge threat to public health, which has increased the difficulty and transmission of disease treatment, as well as the burden and cost of medical institutions. In response to the current problems and challenges in inflammation control and treatment of bacterial infected wounds, inspired by antibacterial mechanisms based on active elements such as N, S, Cu and tannic acid (TA), a highly efficient multifunctional carbon quantum dot platform was proposed in this study and constructed through their special assembly in a solvothermal reaction system for the treatment of infected wounds. By introducing active elements such as N, S and Cu, this carbon quantum dot platform is endowed with antibacterial properties, while also achieving good angiogenesis promoting performance through the use of ion Cu. Meanwhile, the good antioxidant activity of TA (one of the precursors used) enables this platform to have better immunomodulatory performance in vivo. The research results on the treatment of bacterial infection models indicate that the multifunctional carbon quantum dots obtained can accelerate the healing of infected wounds by inhibiting bacterial infection, regulating immunoreaction, accelerating collagen deposition and promoting angiogenesis. This multifunctional carbon quantum dot platform shows good clinical application prospects in treating bacterial infected wounds. Additionally, the fluorescence characteristics of such carbon dots can be expected to realize visual therapy in the future.

Enhancing tumor photodynamic synergistic therapy efficacy through generation of carbon radicals by Prussian blue nanomedicine

Significant progress has been achieved in tumor therapies utilizing nano-enzymes which could convert hydrogen peroxide into reactive oxygen species (ROS). However, the ROS generated by these enzymes possess a short half-life and exhibit limited diffusion within cells, making it challenging to inflict substantial damage on major organelles for effective tumor therapy. Therefore, it becomes crucial to develop a novel nanoplatform that could extend radicals half-life. Artesunate (ATS) is a Fe (II)-dependent drug, while the limited availability of iron (II), coupled with the poor aqueous solubility of ATS, limits its application. Here, Prussian blue (PB) was selected as a nano-carrier to release Fe (II), thus constructing a hollow Prussian blue/artesunate/methylene blue (HPB/ATS/MB) nanoplatform. HPB degraded and released iron(III), ATS and MB, under the combined effects of NIR irradiation and the unique tumor microenvironment. Moreover, Fe (III) exploited GSH to formation of Fe (II), disturbing the redox homeostasis of tumor cells and Fe (II) reacted with H2O2 and ATS to generate carbon radicals with a long half-life in situ. Furthermore, MB generates 1O2 under laser irradiation conditions. In vitro and in vivo experiments have demonstrated that the HPB/ATS/MB NPs exhibit a synergistic therapeutic effect through photothermal therapy, photodynamic therapy and radical therapy.

Toward Fully Automated Personalized Orthopedic Treatments: Innovations and Interdisciplinary Gaps

Personalized orthopedic devices are increasingly favored for their potential to enhance long-term treatment success. Despite significant advancements across various disciplines, the seamless integration and full automation of personalized orthopedic treatments remain elusive. This paper identifies key interdisciplinary gaps in integrating and automating advanced technologies for personalized orthopedic treatment. It begins by outlining the standard clinical practices in orthopedic treatments and the extent of personalization achievable. The paper then explores recent innovations in artificial intelligence, biomaterials, genomic and proteomic analyses, lab-on-a-chip, medical imaging, image-based biomechanical finite element modeling, biomimicry, 3D printing and bioprinting, and implantable sensors, emphasizing their contributions to personalized treatments. Tentative strategies or solutions are proposed to address the interdisciplinary gaps by utilizing innovative technologies. The key findings highlight the need for the non-invasive quantitative assessment of bone quality, patient-specific biocompatibility, and device designs that address individual biological and mechanical conditions. This comprehensive review underscores the transformative potential of these technologies and the importance of multidisciplinary collaboration to integrate and automate them into a cohesive, intelligent system for personalized orthopedic treatments.

Sustainable Release Selenium Laden with SiO2 Restoring Peripheral Nerve Injury via Modulating PI3K/AKT Pathway Signaling Pathway

Background

Inhibiting ROS overproduction is considered a very effective strategy for the treatment of peripheral nerve injuries, and Se has a remarkable antioxidant effect; however, since the difference between the effective concentration of Se and the toxic dose is not large, we synthesized a nanomaterial that can release Se slowly so that it can be used more effectively.

Methods

Se@SiO2 NPs were synthesized using a mixture of Cu2-x Se nanocrystals, and the mechanism of action of Se@SiO2 NPs was initially explored by performing sequencing, immunofluorescence staining and Western blotting of cellular experiments. The mechanism of action of Se@SiO2 NPs was further determined by performing behavioral assays after animal experiments and by sampling the material for histological staining, immunofluorescence staining, and ELISA. The effects, mechanisms and biocompatibility of Se@SiO2 NPs for peripheral nerve regeneration were determined.

Results

Porous Se@SiO2 was successfully synthesized, had good particle properties, and could release Se slowly. CCK-8 experiments revealed that the optimal experimental doses were 100 μM H2O2 and 200 μg/mL Se@SiO2, and RNA-seq revealed that porous Se@SiO2 was associated with cell proliferation, apoptosis, and the PI3K/AKT pathway. WB showed that porous Se@SiO2 could increase the expression of cell proliferation antigens (PCNA and S100) and antiapoptotic proteins (Bcl-2), decrease the expression of proapoptotic proteins (Bax), and increase the expression of antioxidative stress proteins (Nrf2, HO-1, and SOD2). EdU cell proliferation and ROS fluorescence assays showed that porous Se@SiO2 promoted cell proliferation and reduced ROS levels. The therapeutic effect of LY294002 (a PI3K/AKT pathway inhibitor) was decreased significantly and its effect was lost when it was added simultaneously with porous Se@SiO2. Animal experiments revealed that the regenerated nerve fiber density, myelin thickness, axon area, gastrocnemius muscle wet-to-weight ratio, myofiber area, sciatic nerve function index (SFI), CMAP, apoptotic cell ratio, and levels of antioxidative stress proteins and anti-inflammatory factors were increased following the administration of porous Se@SiO2. The levels of oxidative stress proteins and anti-inflammatory factors were significantly greater in the Se@SiO2 group than in the PNI group, and the effect of LY294002 was decreased significantly and was lost when it was added simultaneously with porous Se@SiO2.

Conclusion

Se@SiO2 NPs are promising, economical and effective Se-releasing nanomaterials that can effectively reduce ROS production, inhibit apoptosis and promote cell proliferation after nerve injury via the PI3K/AKT pathway, ultimately accelerating nerve regeneration. These findings could be used to design new, promising drugs for the treatment of peripheral nerve injury.

Regulatory science promotes the translation of transcatheter tricuspid valve repair/replacement devices

For patients with symptomatic and severe tricuspid regurgitation but inoperable with open surgery, transcatheter tricuspid valve intervention (TTVI) is a procedure of great clinical value. TTVI products include repair and replacement devices. TTVI products are one of the hotspots of investigation now, with different innovative biomaterials and structural designs in trials to satisfy divergent indications and reduce complications. With the emerging biomaterials, the technical difficulty of structural design will be greatly reduced, spurring further product innovation and development. The innovativeness and complexity of TTVI products have brought challenges to academia, industry, and regulatory agencies. Regulatory science provides a bridge to address these difficulties and challenges. This perspective article introduces the latest development of the TTVI products. With traditional methods, regulatory agencies face challenges in evaluating the safety and efficacy of TTVr/TTVR devices given the uncertainty of clinical use and the diversity of innovative structural design. This perspective article analyzes the regulatory challenges and discusses regulatory science that can be developed to assess the safety, efficacy, quality and performance of such products: including new approaches for innovative devices, pre-review path, computer modeling and simulation, accelerated wear testing methods for transcatheter heart valves and evidence-based research. This article reveals for the first time how to apply regulatory science systematically to TTVI products, which is of great relevance to their development and translation.

Dissolvable microneedles loaded ginsenoside Rg3 liposome: a transdermal delivery approach for alopecia treatment

The skin stratum corneum (SC) barrier function will interfere with the absorption of topical treatment and reduce the drug's therapeutic effect on alopecia. Microneedles (MNs) can penetrate the skin barrier and deliver drugs to the dermis. Furthermore, MNs can mechanically stimulate the skin, which promotes hair growth. Thus, we designed a green and dissolvable composite microneedle made of hyaluronic acid (HA) and Bletilla striata polysaccharide (BSP) to encapsulate cholesterol-free ginsenoside Rg3 liposomes (Rg3-LPs) to avoid cholesterol metabolism-producing testosterone to inhibit hair regeneration and minimize the effect of the SC barrier on liposomes absorption. HA and BSP can enhance the mechanical strength of Rg3-MNs to ensure the transport of liposomes to the hair follicle (HF) region while causing minimal skin irritation and guaranteeing cell compatibility. In addition, HA increased hair density and was more conducive to hair regeneration. In telogen effluvium (TE) and testosterone-induced androgenetic alopecia (AGA) animals, Rg3-MNs achieved comparable efficacy to minoxidil with low-frequency treatment and the quality of regenerated hair was higher. Furthermore, quantitative characterization and transcriptome sequencing results showed that Rg3-MNs promoted hair regeneration by promoting the expression of Wnt3a and Wnt10b genes, activating the Wnt/β-catenin pathway. Therefore, Rg3-MNs present broad prospects in the treatment of alopecia.

Electrophoretic Deposition of Chitosan Coatings on the Porous Titanium Substrate

Medicine is looking for solutions to help implant patients recover more smoothly. The porous implants promote osteointegration, thereby providing better stabilization. Introducing porosity into metallic implants enhances their biocompatibility and facilitates osteointegration. The introduction of porosity is also associated with a reduction in Young's modulus, which reduces the risk of tissue outgrowth around the implant. However, the risk of chronic inflammation remains a concern, necessitating the development of coatings to mitigate adverse reactions. An interesting biomaterial for such modifications is chitosan, which has antimicrobial, antifungal, and osteointegration properties. In the present work, a porous titanium biomaterial was obtained by powder metallurgy, and electrophoretic deposition of chitosan coatings was used to modify its surface. This study investigated the influence of ethanol content in the deposition solution on the quality of chitosan coatings. The EPD process facilitates the control of coating thickness and morphology, with higher voltages resulting in thicker coatings and increased pore formation. Ethanol concentration in the solution affects coating quality, with higher concentrations leading to cracking and peeling. Optimal coating conditions (30 min/10 V) yield high-quality coatings, demonstrating excellent cell viability and negligible cytotoxicity. The GIXD and ATR-FTIR analysis confirmed the presence of deposited chitosan coatings on Ti substrates. The microstructure of the chitosan coatings was examined by scanning electron microscopy. Biological tests showed no cytotoxicity of the obtained materials, which allows for further research and the possibility of their use in medicine. In conclusion, EPD offers a viable method for producing chitosan-based coatings with controlled properties for biomedical applications, ensuring enhanced patient outcomes and implant performance.

Fluorinated Organic Polymers for Cancer Drug Delivery

In the realm of cancer therapy, the spotlight is on nanoscale pharmaceutical delivery systems, especially polymer-based nanoparticles, for their enhanced drug dissolution, extended presence in the bloodstream, and precision targeting achieved via surface engineering. Leveraging the amplified permeation and retention phenomenon, these systems concentrate therapeutic agents within tumor tissues. Nonetheless, the hurdles of systemic toxicity, biological barriers, and compatibility with living systems persist. Fluorinated polymers, distinguished by their chemical idiosyncrasies, are poised for extensive biomedical applications, notably in stabilizing drug metabolism, augmenting lipophilicity, and optimizing bioavailability. Material science heralds the advent of fluorinated polymers that, by integrating fluorine atoms, unveil a suite of drug delivery merits: the hydrophobic traits of fluorinated alkyl chains ward off lipid or protein disruption, the carbon-fluorine bond's stability extends the drug's lifecycle in the system, and a lower alkalinity coupled with a diminished ionic charge bolsters the drug's ability to traverse cellular membranes. This comprehensive review delves into the utilization of fluorinated polymers for oncological pharmacotherapy, elucidating their molecular architecture, synthetic pathways, and functional attributes, alongside an exploration of their empirical strengths and the quandaries they encounter in both experimental and clinical settings.

Global Stem Cell Research in Orthopaedics: A Bibliometric Study from 1995 to 2020

Background

The research field of stem cell-based therapies in orthopaedics has witnessed significant growth in the recent past. We aimed to identify and analyze the bibliometric characteristics of the global highly cited papers (HCPs) in stem cell research in orthopaedics.

Methods

This study relied on secondary data extracted from Scopus, Elsevier's abstract and citation database. An advanced search string was employed, for the period from 1995 to 2020. For each paper, the extracted information included the number of citations, title, authors (name, number, authorship position, and country), year of publication, title of the journals, study design, and thematic field. The VOSviewer (1.6.20) was used to uncover relationships between authors, institutions, keywords, and publications.

Results

There were a total of 1427 publications and out of these 186 papers had 100 or more citations (range 100-2644) and were considered as HCPs. The average citation per paper (CPP) was 265.8. Only 4% of the top HCPs contributed 20% of the total citations of all HCPs. All the HCPs were published from high-income countries, and the USA was the leading country in all aspects of publication on stem cell research. Méndez-Ferrer S registered the highest citation (n = 2644), Prockop DJ was the most prolific author (n = 8 papers), and Harvard Medical School, USA emerged as the most prolific organization with 12 HCPs.

Conclusion

Global research in stem cell therapies for orthopaedic problems is making strides, and is an emerging field of research. Stem cell research offers the potential for improved treatment outcomes for various musculoskeletal conditions.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01160-0.

The therapeutic efficacy of different configuration nano-polydopamine drug carrier systems with photothermal synergy against head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignant tumor worldwide. Considering its special anatomical site and the progressive resistance to chemotherapy drugs, the development of more effective, minimally invasive and precise treatment methods is urgently needed. Nanomaterials, given their special properties, can be used as drug carrier systems to improve the therapeutic effect and reduce the adverse effects. The drug carrier systems with photothermal effect can promote the killing of cancer cells and help overcome drug resistance through heat stress. We selected dopamine, a simple raw material, and designed and synthesized three different configurations of nano-polydopamine (nPDA) nanomaterials, including nPDA balls, nPDA plates and porous nPDA balls. In addition to the self-polymerization and self-assembly, nPDA has high photothermal conversion efficiency and can be easily modified. Moreover, we loaded cisplatin into three different configurations of nPDA, creating nPDA-cis (the nano-drug carrier system with cisplatin), and comparatively studied the properties and antitumor effects of all the nPDA and nPDA-cis materials in vitro and nPDA-cis in vivo. We found that the photothermal effect of the nPDA-cis balls drug carrier system had synergistic effect with cisplatin, resulting in excellent antitumor effect and good clinical application prospects. The comparison of the three different configurations of drug carrier systems suggested the importance of optimizing the spatial configuration design and examining the physical and chemical properties in the future development of nano-drug carrier systems. In this study, we also noted the duality and complexity of the influences of heat stress on tumors in vitro and in vivo. The specific mechanisms and the synergy with chemotherapy and immunotherapy will be an important research direction in the future.