Angiogenic Hyaluronic Acid Hydrogels with Curcumin-Coated Magnetic Nanoparticles for Tissue Repair

Hydrogel-integrated exosome mimetics derived from osteogenically induced mesenchymal stem cells in spheroid culture enhance bone regeneration

Exosomes derived from mesenchymal stem cells (MSCs) offer a promising alternative to traditional cell-based therapies for tissue repair by mitigating risks associated with the transplantation of living cells. However, insufficient osteogenic capacity of exosomes diminishes their potential in bone tissue regeneration. Here, we report novel osteogenically induced exosome mimetics (EMs) integrated into injectable hydrogel carriers for improved bone regeneration. EMs were produced by a serial extrusion of MSCs cultured as spheroids during osteogenic induction. The prepared EMs were chemically anchored on a self-healing hydrogel assembled by guanidinylated hyaluronic acid and silica-rich nanoclays for sustained release of EMs. The administration of hydrogel-integrated EMs into mouse calvarial defects resulted in robust bone tissue regeneration. miRNA sequencing revealed altered expression of specific miRNAs in the EMs related to Wnt/β-catenin and Notch signaling pathways. Our study provides new insights into the development of advanced exosome-based cell-free therapies for bone tissue engineering.

pH-responsive and self-adaptive injectable sodium alginate/carboxymethyl chitosan hydrogel accelerates infected wound healing by bacteriostasis and immunomodulation

Infected wound healing is a global medical challenge due to persistent bacterial infection and excess inflammation. Designing microenvironment-responsive and self-adaptive hydrogels with antibacterial and anti-inflammatory properties is expected to be an effective strategy to promote infected wound healing. In this study, a self-adaptive injectable sodium alginate/carboxymethyl chitosan hydrogel (SCSC) for pH-responsive release of curcumin has been prepared at room temperature by simple stirring. The incorporation of the crosslinker, Sr2+, enhances mechanical properties of SCSC hydrogel by tensing network structures, and provides synergistic biological activities. Meanwhile, SCSC hydrogel self-adapts in irregular wound shapes with outstanding ECM-like performance and releases effectively in the acidic microenvironment simulating the initial stage of infected wounds. SCSC hydrogel with good biocompatibility can promote cell migration, while relieving oxidative stress and mitochondria damage. Notably, SCSC hydrogel inhibits inflammatory factor expression and promotes M2 macrophage polarization by suppressing the NF-κB signaling pathway. Further, SCSC hydrogel significantly downregulates the over-expression of matrix metalloproteinase-9 (MMP-9), thereby helping promote ECM reconstruction. In vivo experiment results further demonstrate that SCSC hydrogel accelerates the re-epithelialization of infected wounds on the back of rats. Thus, the pH-responsive and self-adaptive SCSC hydrogel possesses great potential in the management and control of infected wounds.

Assessment of Potential Toxicity of Hyaluronic Acid-Coated Magnetic Nanoparticles on Maize (Zea mays) at Early Development Stages

The effectiveness of iron oxide nanoparticles in enhancing crop plant development depends on their stabilization. In this study, the effect of hyaluronic acid (HA), used both as a stabilizer for iron oxide nanoparticles (HA-MNP) and independently, was evaluated in maize seedlings. Different concentrations of HA-MNP (0.625-7.5 mg/L) were tested alongside a 0.01% HA solution. Growth parameters, antioxidant enzyme activities (peroxidase and polyphenol oxidase), photosynthetic pigments (chlorophyll and carotenoids), phenolic content, and genotoxicity were analyzed. While HA alone led to slight decreases in seedling length, pigment content, and polyphenol levels compared to the control, it increased peroxidase activity and mitotic index. Lower concentrations of HA-MNP (below 2.5 mg/L) enhanced seedling growth, likely due to improved iron uptake, whereas higher concentrations reduced pigment and phenolic content. All HA-MNP concentrations induced genotoxic effects, which was proven by an increased mitotic index and chromosomal aberrations, indicating both positive and defensive plant responses to oxidative stress. These findings suggest a complex interaction between HA, HA-MNP, and maize seedlings, where HA concentrations play a significant role in modulating growth and stress response, while higher concentrations may induce toxicity.

Nanocurcumin in myocardial infarction therapy: emerging trends and future directions

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. Curcumin has been observed to significantly reduce pathological processes associated with MI. Its clinical application is limited due to its low bioavailability, rapid degradation, and poor solubility. Advancements in nanotechnology can be used to enhance its therapeutic potentials in MI. Curcumin nano-formulation enhances its solubility, stability, and bioavailability, allowing more precise delivery to ischemic cardiac tissue. Curcumin nanoparticles have been observed to successfully reduce infarct size, maintain heart function by modulating essential molecular pathways in MI. Its liposomal formulations provide sustained release and higher tissue penetration with improved pharmacokinetics and enhanced therapeutic efficacy. Preclinical studies revealed that nanocurcumin drastically lower oxidative stress indicators, inflammatory cytokines, and cardiac damage. Micelles composed of polymers have demonstrated high biocompatibility and targeting capabilities with increased cardio-protective effects. Research and clinical trials are essential for comprehensive analysis and efficacy of curcumin-based nano-therapeutics in cardiovascular condition and lowering risk of MI.

Nanoparticle-Mediated Gene Delivery for Bone Tissue Engineering

Critical-sized bone defects represent an urgent clinical problem, necessitating innovative treatment approaches. Gene-activated grafts for bone tissue engineering have emerged as a promising solution. However, traditional gene delivery methods are constrained by limited osteogenic efficacy and safety concerns. Recently, organic and inorganic nanoparticle (NP) vectors have attracted significant attention in bone tissue engineering for their safe, stable, and controllable gene delivery. Targeted gene delivery guided by insights into bone healing mechanisms, coupled with the multifunctional design of NPs, is crucial for enhancing therapeutic outcomes. Here, the theoretical foundations underlying NP-mediated gene therapy for enhancing bone healing across different histological stages are elucidated. Furthermore, the distinct attributes of functionalized NP vectors are discussed, and cutting-edge strategies aimed at optimizing gene delivery efficiency throughout the therapeutic process are highlighted. Additionally, the review addresses the unresolved challenges and prospects of this technology. This review may contribute to the continued development and clinical application of NP-mediated gene delivery for treating critical-sized bone defects.

Hyaluronic Acid Role in Biomaterials Prevascularization

Tissue vascularization is a major bottleneck in tissue engineering. In this review, the state of the art on the intricate role of hyaluronic acid (HA) in angiogenesis is explored. HA plays a twofold role in angiogenesis. First, when released as a free polymer in the extracellular matrix (ECM), HA acts as a signaling molecule triggering multiple cascades that foster smooth muscle cell differentiation, migration, and proliferation thereby contributing to vessel wall thickening. Simultaneously, HA bound to the plasma membrane in the pericellular space functions as a polymer block, participating in vessel formation. Starting with the HA origins in native vascular tissues, the approaches aimed at achieving vascularization in vivo are reviewed. The significance of HA molecular weight (MW) in angiogenesis and the challenges associated with utilizing HA in vascular tissue engineering (VTE) are conscientiously addressed. The review finally focuses on a thorough examination and comparison of the diverse strategies adopted to harness the benefits of HA in the vascularization of bioengineered materials. By providing a nuanced perspective on the multifaceted role of HA in angiogenesis, this review contributes to the ongoing discourse in tissue engineering and advances the collective understanding of optimizing vascularization processes assisted by functional biomaterials.

Exosomes from mesenchymal stem cells: Potential applications in wound healing

Wound healing is a continuous and complex process regulated by multiple factors, which has become an intractable clinical burden. Mesenchymal stem cell-derived exosomes (MSC-exos) possess low immunogenicity, easy preservation, and potent bioactivity, which is a mirror to their parental cells MSC-exos are important tools for regulating the biological behaviors of wound healing-associated cells, including fibroblasts, keratinocytes, immune cells, and endothelial cells. MSC-exos accelerate the wound healing process at cellular and animal levels by modulating inflammatory responses, promoting collagen deposition and vascularization. MSC-exos accelerate wound healing at the cellular and animal levels by modulating inflammatory responses and promoting collagen deposition and vascularization. This review summarizes the roles and mechanisms of MSC-exos originating from various sources in promoting the healing efficacy of general wounds, diabetic wounds, burn wounds, and healing-related scars. It also discusses the limitations and perspectives of MSC-exos in wound healing, in terms of exosome acquisition, mechanistic complexity, and exosome potentiation modalities. A deeper understanding of the properties and functions of MSC-exos is beneficial to advance the therapeutic approaches for achieving optimal wound healing.

Magnetic engineering nanoparticles: Versatile tools revolutionizing biomedical applications

The use of nanoparticles has increased significantly over the past few years in a number of fields, including diagnostics, biomedicine, environmental remediation, and water treatment, generating public interest. Among various types of nanoparticles, magnetic nanoparticles (MNPs) have emerged as an essential tool for biomedical applications due to their distinct physicochemical properties compared to other nanoparticles. This review article focuses on the recent growth of MNPs and comprehensively reviews the advantages, multifunctional approaches, biomedical applications, and latest research on MNPs employed in various biomedical techniques. Biomedical applications of MNPs hold on to their ability to rapidly switch magnetic states under an external field at room temperature. Ideally, these MNPs should be highly susceptible to magnetization when the field is applied and then lose that magnetization just as quickly once the field is removed. This unique property allows MNPs to generate heat when exposed to high-frequency magnetic fields, making them valuable tools in developing treatments for hyperthermia and other heat-related illnesses. This review underscores the role of MNPs as tools that hold immense promise in transforming various aspects of healthcare, from diagnostics and imaging to therapeutic treatments, with discussion on a wide range of peer-reviewed articles published on the subject. At the conclusion of this work, challenges and potential future advances of MNPs in the biomedical field are highlighted.

Magnetic fibrin nanofiber hydrogel delivering iron oxide magnetic nanoparticles promotes peripheral nerve regeneration

Peripheral nerve injury is a debilitating condition that have a profound impact on the overall quality of an individual's life. The repair of peripheral nerve defects continues to present significant challenges in the field. Iron oxide magnetic nanoparticles (IONPs) have been recognized as potent nanotools for promoting the regeneration of peripheral nerves due to their capability as biological carriers and their ability to template the hydrogel structure under an external magnetic field. This research used a fibrin nanofiber hydrogel loaded with IONPs (IONPs/fibrin) to promote the regeneration of peripheral nerves in rats. In vitro examination of PC12 cells on various concentrations of IONPs/fibrin hydrogels revealed a remarkable increase in NGF and VEGF expression at 2% IONPs concentration. The biocompatibility and degradation of 2% IONPs/fibrin hydrogel were assessed using the in vivo imaging system, demonstrating subcutaneous degradation within a week without immediate inflammation. Bridging a 10-mm sciatic nerve gap in Sprague Dawley rats with 2% IONPs/fibrin hydrogel led to satisfactory morphological recovery of myelinated nerve fibers. And motor functional recovery in the 2% IONPs/fibrin group was comparable to autografts at 6, 9 and 12 weeks postoperatively. Hence, the composite fibrin hydrogel incorporating 2% IONPs exhibits potential for peripheral nerve regeneration.

The Recent Applications of Magnetic Nanoparticles in Biomedical Fields

Magnetic nanoparticles (MNPs) have found extensive application in the biomedical domain due to their enhanced biocompatibility, minimal toxicity, and strong magnetic responsiveness. MNPs exhibit great potential as nanomaterials in various biomedical applications, including disease detection and cancer therapy. Typically, MNPs consist of a magnetic core surrounded by surface modification coatings, such as inorganic materials, organic molecules, and polymers, forming a nucleoshell structure that mitigates nanoparticle agglomeration and enhances targeting capabilities. Consequently, MNPs exhibit magnetic responsiveness in vivo for transportation and therapeutic effects, such as enhancing medical imaging resolution and localized heating at the site of injury. MNPs are utilized for specimen purification through targeted binding and magnetic separation in vitro, thereby optimizing efficiency and expediting the process. This review delves into the distinctive functional characteristics of MNPs as well as the diverse bioactive molecules employed in their surface coatings and their corresponding functionalities. Additionally, the advancement of MNPs in various applications is outlined. Additionally, we discuss the advancements of magnetic nanoparticles in medical imaging, disease treatment, and in vitro assays, and we anticipate the future development prospects and obstacles in this field. The objective is to furnish readers with a thorough comprehension of the recent practical utilization of MNPs in biomedical disciplines.

Black Phosphorus-Based Dynamic Self-Healing Hydrogel to Integrate Demineralized Bone Matrix and Noggin-Targeting siRNA for Synergistic Osteogenesis

Although a demineralized bone matrix (DBM) is often used as an alternative to an autologous bone graft, its clinical application is still hampered by easy dispersion of DBM particles and insufficient osteoinductivity in the defect site. Herein, we designed a self-healing hydrogel for DBM that can rapidly restore its structural integrity after damage based on amino-rich black phosphorus (BP) nanosheets and aldehyde-functionalized hyaluronic acid (AHA). Given the increased expression of bone morphogenetic protein (BMP) antagonists by DBM stimulation, the osteogenic potency of DBM in the hydrogel carrier was further enhanced by abrogating the BMP antagonism. The BP/AHA hydrogel provided dynamic polymer-nanosheet networks that combine injectability, modability, and physical stability with high DBM loading, where the BP nanosheets served as osteogenic cross-linkers to promote biomineralization and deliver siRNA to suppress undesirable expression of BMP antagonist noggin by DBM. As a result, the BP/AHA hydrogel integrated with DBM and noggin-targeting siRNA synergistically promoted osteogenic differentiation of mesenchymal stem cells by enhancing BMP/Smad signaling. This work demonstrates a promising strategy to improve the efficacy of bone regeneration using bone graft.

Multi-Functional Nano-Doped Hollow Fiber from Microfluidics for Sensors and Micromotors

Nano-doped hollow fiber is currently receiving extensive attention due to its multifunctionality and booming development. However, the microfluidic fabrication of nano-doped hollow fiber in a simple, smooth, stable, continuous, well-controlled manner without system blockage remains challenging. In this study, we employ a microfluidic method to fabricate nano-doped hollow fiber, which not only makes the preparation process continuous, controllable, and efficient, but also improves the dispersion uniformity of nanoparticles. Hydrogel hollow fiber doped with carbon nanotubes is fabricated and exhibits superior electrical conductivity (15.8 S m-1), strong flexibility (342.9%), and versatility as wearable sensors for monitoring human motions and collecting physiological electrical signals. Furthermore, we incorporate iron tetroxide nanoparticles into fibers to create magnetic-driven micromotors, which provide trajectory-controlled motion and the ability to move through narrow channels due to their small size. In addition, manganese dioxide nanoparticles are embedded into the fiber walls to create self-propelled micromotors. When placed in a hydrogen peroxide environment, the micromotors can reach a top speed of 615 μm s-1 and navigate hard-to-reach areas. Our nano-doped hollow fiber offers a broad range of applications in wearable electronics and self-propelled machines and creates promising opportunities for sensors and actuators.

Multifunctional Self-Assembled Block Copolymer/Iron Oxide Nanocomposite Hydrogels Formed from Wormlike Micelles

This article reports the preparation of multifunctional magnetic nanocomposite hydrogels formed from wormlike micelles. Specifically, iron oxide nanoparticles were incorporated into a temperature responsive block copolymer, poly(glycerol monomethacrylate)-b-poly(2-hydroxypropyl methacrylate) (PGMA-b-PHPMA), and graphene oxide (GO) dispersion at a low temperature (∼2 °C) through high-speed mixing and returning the mixture to room temperature, resulting in the formation of nanocomposite gels. The optimal concentrations of iron oxide and GO enhanced the gel strength of the nanocomposite gels, which exhibited a strong magnetic response when a magnetic field was applied. These materials retained the thermoresponsiveness of the PGMA-PHPMA wormlike micelles allowing for a solid-to-liquid transition to occur when the temperature was reduced. The mechanical and rheological properties and performance of the nanocomposite gels were demonstrated to be adjustable, making them suitable for a wide range of potential applications. These nanocomposite worm gels were demonstrated to be relatively adhesive and to act as strain and temperature sensors, with the measured electrical resistance of the nanocomposite gels changing with applied strain and temperature sweeps. The nanocomposite gels were found to recover efficiently after the application of high shear with approximately 100% healing efficiency within seconds. Additionally, these nanocomposite worm gels were injectable, and the addition of GO and iron oxide nanomaterials seemed to have no significant adverse impact on the biocompatibility of the copolymer gels, making them suitable not only for 3D printing in nanocomposite engineering but also for potential utilization in various biomedical applications as an injectable magnetic responsive hydrogel.

Multifunctional Hydrogel Enhances Inflammatory Control, Antimicrobial Activity, and Oxygenation to Promote Healing in Infectious Wounds

Chronic infected wounds often fail to heal through normal repair mechanisms, and the persistent response of reactive oxygen species (ROS) and inflammation is a major contributing factor to the difficulty in their healing. In this context, we developed an ROS-responsive injectable hydrogel. This hydrogel is composed of ε-polylysine grafted (EPL) with caffeic acid (CA) and hyaluronic acid (HA) grafted with phenylboronic acid (PBA). Before the gelation process, a mixture CaO2@Cur-PDA (CCP) consisting of calcium peroxide (CaO2) coated with polydopamine (PDA) and curcumin (Cur) is embedded into the hydrogel. Under the conditions of chronic refractory wound environments, the hydrogel gradually dissociates. HA mimics the function of the extracellular matrix, while the released caffeic acid-grafted ε-polylysine (CE) effectively eliminates bacteria in the wound vicinity. Additionally, released CA also clears ROS and influences macrophage polarization. Subsequently, CCP further decomposes, releasing Cur, which promotes angiogenesis. This multifunctional hydrogel accelerates the repair of diabetic skin wounds infected with Staphylococcus aureus in vivo and holds promise as a candidate dressing for the healing of chronic refractory wounds.

Self-Assembled Nanocomposite Hydrogels as Carriers for Demineralized Bone Matrix Particles and Enhanced Bone Repair

Demineralized bone matrix (DBM) has been widely used as an allogeneic alternative to autologous bone graft for bone repair. However, more extensive use of DBM is limited due to its particulate nature after demineralization and rapid particle dispersion following irrigation, resulting in unpredictable osteoinductivity. Here, a new design of injectable hydrogel carriers for DBM that combine self-healing ability and osteogenic properties based on the self-assembly of guanidinylated hyaluronic acid and silica-rich nanoclays is reported. The nanoclays serve as reversible linkages to form a dynamic hydrogel network with the guanidine moieties on the polymer chains. Gelation kinetics and mechanical properties can be controlled by altering nanoclay content in the hydrogel. The resulting hydrogel exerts self-healing ability due to its dynamic crosslinks and well retains its overall performance with high DBM loading. The hydrogel exhibits great cytocompatibility and osteogenic effects mediated by the nanoclays. In vivo delivery of DBM using the nanocomposite hydrogel further demonstrates robust bone regeneration in a mouse calvarial defect model in comparison to DBM delivered with aqueous HA. This work suggests a promising hydrogel platform for many applications including therapeutic delivery and tissue engineering.

A Multifunctional, Tough, Stretchable, and Transparent Curcumin Hydrogel with Potent Antimicrobial, Antioxidative, Anti-inflammatory, and Angiogenesis Capabilities for Diabetic Wound Healing

The treatment of diabetic chronic wounds is still faced with great challenges, mainly due to wound infection, excessive inflammation, and peripheral vascular disease in the wound area. Therefore, it is of great importance to develop a novel multifunctional hydrogel with high efficiency to accelerate diabetic wound healing. Curcumin (Cur), a Chinese herbal, has shown great potential in enhancing the healing of diabetic chronic wounds because of its immunomodulatory and pro-angiogenic properties. However, its low aqueous solubility, poor bioavailability, and chemical instability have limited its clinical applications. To address these current bottlenecks, novel poly(vinyl alcohol) (PVA)-chitosan (CS)/sodium alginate (SA)-Cur (PCSA) hydrogels were prepared for the first time, and they demonstrated all of the above intriguing performances by the Michael addition reaction of CS and Cur. PCSA hydrogels show multiple dynamic bonds, which possess strong mechanical properties (tensile stress: ∼0.980 MPa; toughness: ∼258.45 kJ/m3; and compressive strength: ∼7.38 MPa at strain of 80%). These intriguing performances provided an optimal microenvironment for cell migration and proliferation and also promoted the growth of blood vessels, leading to early angiogenesis. Importantly, the experimental results demonstrated that PCSA hydrogels can effectively transform pro-inflammatory M1 macrophages into anti-inflammatory M2 macrophages without the need for additional ingredients in vitro. Benefiting from these characteristics, a full-thickness diabetic wound in a rat model demonstrated that PCSA hydrogels can effectively accelerate wound healing via ROS-scavenging, downregulation of IL-1β, and upregulation of CD31 expression, resulting in angiogenesis and collagen deposition. This strategy not only provides a simple and safe Cur-based hydrogel for diabetic wound healing but also highlights the significant potential for the development of high-performance biomaterials for promoting diabetic wound healing using traditional Chinese medicine.

Morphologically transformable peptide nanocarriers coloaded with doxorubicin and curcumin inhibit the growth and metastasis of hepatocellular carcinoma

In tumor treatment, the highly disordered vascular system and lack of accumulation of chemotherapeutic drugs in tumors severely limit the therapeutic role of nanocarriers. Smaller drug-containing nanoparticles (NPs) can better penetrate the tumor but are easily removed, which severely limits the tumor-killing properties of the drug. The chemotherapeutic medication doxorubicin (DOX) is highly toxic to the heart, but this toxicity can be effectively mitigated and the combined anticancer effect can be enhanced by clinically incorporating curcumin (CUR) as part of the dual therapy. We designed a small-molecule peptide, Pep1, containing a targeting peptide (CREKA) and a pH-responsive moiety. These NPs can target the blood vessels in tumor microthrombi and undergo a morphological shift in the tumor microenvironment. This process enhances the penetration and accumulation of drugs, ultimately improving the effectiveness of cancer treatment. In vitro and in vivo experiments demonstrated that this morphological transformation allowed rapid and effective drug release into tumors, the effective inhibition of tumor angiogenesis, and the promotion of tumor cell apoptosis, thus effectively killing tumor cells. Our findings provide a novel and simple approach to nhibit the growth and metastasis of hepatocellular carcinoma.

Hyaluronic Acid-Based Reactive Oxygen Species-Responsive Multifunctional Injectable Hydrogel Platform Accelerating Diabetic Wound Healing

Diabetic wounds are more likely to develop into complex and severe chronic wounds. The objective of this study is to develop and assess a reactive oxygen species (ROS)-responsive multifunctional injectable hydrogel for the purpose of diabetic wound healing. A multifunctional hydrogel (HA@Cur@Ag) is successfully synthesized with dual antioxidant, antibacterial, and anti-inflammatory properties by crosslinking thiol hyaluronic acid (SH-HA) and disulfide-bonded hyperbranched polyethylene glycol (HB-PBHE) through Michael addition; while, incorporating curcumin liposomes and silver nanoparticles (AgNPs). The HA@Cur@Ag hydrogel exhibits favorable biocompatibility, degradability, and injectivity. The outcomes of in vitro and in vivo experiments demonstrate that the hydrogel can effectively be loaded with and release curcumin liposomes, as well as silver ions, thereby facilitating diabetic wound healing through multiple mechanisms, including ROS scavenging, bactericidal activity, anti-inflammatory effects, and the promotion of angiogenesis. Transcriptome sequencing reveals that the HA@Cur@Ag hydrogel effectively suppresses the activation of the tumour necrosis factor (TNF)/nuclear factor κB (NF-κB) pathway to ameliorate oxidative stress and inflammation in diabetic wounds. These findings suggest that this ROS-responsive multifunctional injectable hydrogel, which possesses the ability to precisely coordinate and integrate intricate biological and molecular processes involved in wound healing, exhibits notable potential for expediting diabetic wound healing.

Inhibitory effect of a novel Curcumin derivative DMC-HA on keloid fibroblasts

Keloids pose a significant dermatological challenge, marked by abnormal fibroblast proliferation and excessive collagen deposition in response to skin injury or trauma. In the present study, we introduce DMC-HA, a derivative of Curcumin, as a promising candidate for keloid treatment. DMC-HA is poised to provide superior therapeutic benefits compared to Curcumin due to its structural modifications. Examining the comparative effects of DMC-HA and Curcumin on keloid fibroblasts can offer insights into their potential as therapeutic agents and the underlying mechanisms in keloid pathogenesis. In our study, CCK-8 experiments revealed that, at equivalent concentrations, DMC-HA demonstrated greater efficacy in inhibiting the proliferation of keloid fibroblasts compared to Curcumin. Flow cytometry analysis indicated that DMC-HA induced fibroblast apoptosis more significantly than Curcumin at the same concentration. Further data demonstrated that DMC-HA notably increased the production of reactive oxygen species (ROS), upregulated the expression levels of Bax, cleaved PARP, and cleaved Caspase-3. Interestingly, the impact of DMC-HA was reversed upon the application of the antioxidant NAC. Additionally, DMC-HA could suppress IL-6-induced increased expression of p-STAT3. Collectively, our findings suggest that DMC-HA is more effective than Curcumin in inhibiting the proliferation of keloid fibroblasts. The underlying mechanism of its action appears to be associated with the augmentation of ROS induction and the concurrent inhibition of STAT3 activation.

Recent trends in preparation and biomedical applications of iron oxide nanoparticles

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

Functional drug-delivery hydrogels for oral and maxillofacial wound healing

The repair process for oral and maxillofacial injuries involves hemostasis, inflammation, proliferation, and remodeling. Injury repair involves a variety of cells, including platelets, immune cells, fibroblasts, and various cytokines. Rapid and adequate healing of oral and maxillofacial trauma is a major concern to patients. Functional drug-delivery hydrogels play an active role in promoting wound healing and have shown unique advantages in wound dressings. Functional hydrogels promote wound healing through their adhesive, anti-inflammatory, antioxidant, antibacterial, hemostatic, angiogenic, and re-epithelialization-promoting properties, effectively sealing wounds and reducing inflammation. In addition, functional hydrogels can respond to changes in temperature, light, magnetic fields, pH, and reactive oxygen species to release drugs, enabling precise treatment. Furthermore, hydrogels can deliver various cargos that promote healing, including nucleic acids, cytokines, small-molecule drugs, stem cells, exosomes, and nanomaterials. Therefore, functional drug-delivery hydrogels have a positive impact on the healing of oral and maxillofacial injuries. This review describes the oral mucosal structure and healing process and summarizes the currently available responsive hydrogels used to promote wound healing.

Magnetic Nanoparticle Coating Decreases the Senescence and Increases the Targeting Potential of Fibroblasts and Adipose-Derived Mesenchymal Stem Cells

Magnetic nanoparticles (MNPs) are intensely scrutinized for applications in emerging biomedical fields. Their potential use for drug delivery, tracking, and targeting agents or for cell handling is tested for regenerative medicine and tissue engineering applications. The large majority of MNPs tested for biomedical use are coated with different lipids and natural or synthetic polymers in order to decrease their degradation process and to increase the ability to transport drugs or bioactive molecules. Our previous studies highlighted the fact that the as-prepared MNP-loaded cells can display increased resistance to culture-induced senescence as well as ability to target pathological tissues; however, this effect tends to be dependent on the cell type. Here, we assessed comparatively the effect of two types of commonly used lipid coatings, oleic acid (OA) and palmitic acid (PA), on normal human dermal fibroblasts and adipose-derived mesenchymal cells with culture-induced senescence and cell motility in vitro. OA and PA coatings improved MNPs stability and dispersibility. We found good viability for cells loaded with all types of MNPs; however, a significant increase was obtained with the as-prepared MNPs and OA-MNPs. The coating decreases iron uptake in both cell types. Fibroblasts (Fb) integrate MNPs at a slower rate compared to adipose-derived mesenchymal stem cells (ADSCs). The as-prepared MNPs induced a significant decrease in beta-galactosidase (B-Gal) activity with a nonsignificant one observed for OA-MNPs and PA-MNPs in ADSCs and Fb. The as-prepared MNPs significantly decrease senescence-associated B-Gal enzymatic activity in ADSCs but not in Fb. Remarkably, a significant increase in cell mobility could be detected in ADSCs loaded with OA-MNPscompared to controls. The OA-MNPs uptake significantly increases ADSCs mobility in a wound healing model in vitro compared to nonloaded counterparts, while these observations need to be validated in vivo. The present findings provide evidence that support applications of OA-MNPs in wound healing and cell therapy involving reparative processes as well as organ and tissue targeting.

In vivo and In vitro properties evaluation of curcumin loaded MgO doped 3D printed TCP scaffolds

The lack of site-specific chemotherapeutic agents to treat bone malignancy throws a significant challenge in the design of a delivery vehicle. The major scientific question posed in this study is, can we utilize curcumin-loaded magnesium oxide (MgO) doped 3D printed tricalcium phosphate (TCP) bone grafts as a localized delivery system that improves early stage in vivo osseointegration and in vitro chemoprevention, antibacterial properties? We have utilized curcumin as an alternative natural chemopreventive agent for bone cancer-specific delivery after direct incorporation on the 3D printed tricalcium phosphate (TCP) bone grafts. The addition of MgO as a dopant to TCP leads to ∼1.3 times enhancement in compressive strength. The designed drug delivery system shows up to ∼22% curcumin release in a physiological pH of 7.4 after 30 days. The presence of curcumin leads to up to ∼8.5 times reduction in osteosarcoma viability. In vitro results indicate that these scaffolds significantly enhance bone-forming osteoblast cells while reducing the bone-resorbing osteoclast cells. The in vivo rat distal femur model surgery followed by histological assessment with H&E, vWF, and Movat pentachrome staining results show that the designed scaffolds lead to new bone formation (up to ∼2.5 times higher than the control) after successful implantation. The presence of MgO and curcumin results in up to ∼71% antibacterial efficacy against osteomyelitis causing S. aureus. These 3D printed osteogenic and chemopreventive scaffolds can be utilized in patient-specific low load-bearing defect sites.

Functional hydrogels for the repair and regeneration of tissue defects

Tissue defects can be accompanied by functional impairments that affect the health and quality of life of patients. Hydrogels are three-dimensional (3D) hydrophilic polymer networks that can be used as bionic functional tissues to fill or repair damaged tissue as a promising therapeutic strategy in the field of tissue engineering and regenerative medicine. This paper summarises and discusses four outstanding advantages of hydrogels and their applications and advances in the repair and regeneration of tissue defects. First, hydrogels have physicochemical properties similar to the extracellular matrix of natural tissues, providing a good microenvironment for cell proliferation, migration and differentiation. Second, hydrogels have excellent shape adaptation and tissue adhesion properties, allowing them to be applied to a wide range of irregularly shaped tissue defects and to adhere well to the defect for sustained and efficient repair function. Third, the hydrogel is an intelligent delivery system capable of releasing therapeutic agents on demand. Hydrogels are capable of delivering therapeutic reagents and releasing therapeutic substances with temporal and spatial precision depending on the site and state of the defect. Fourth, hydrogels are self-healing and can maintain their integrity when damaged. We then describe the application and research progress of functional hydrogels in the repair and regeneration of defects in bone, cartilage, skin, muscle and nerve tissues. Finally, we discuss the challenges faced by hydrogels in the field of tissue regeneration and provide an outlook on their future trends.

Anti-Oxidant Multi-Functionalized Materials: Strontium-Substituted Monetite and Brushite as Delivery Systems for Curcumin

Curcumin has numerous biological activities and pharmaceutical applications related to its ability to inhibit reactive oxygen species. Herein, strontium-substituted monetite (SrDCPA) and strontium-substituted brushite (SrDCPD) were synthesized and further functionalized with curcumin with the aim to develop materials that combine the anti-oxidant properties of the polyphenol, the beneficial role of strontium toward bone tissue, and the bioactivity of calcium phosphates. Adsorption from hydroalcoholic solution increases with time and curcumin concentration, up to about 5-6 wt%, without affecting the crystal structure, morphology, and mechanical response of the substrates. The multi-functionalized substrates exhibit a relevant radical scavenging activity and a sustained release in phosphate buffer. Cell viability, morphology, and expression of the most representative genes were tested for osteoclast seeded in direct contact with the materials and for osteoblast/osteoclast co-cultures. The materials at relatively low curcumin content (2-3 wt%) maintain inhibitory effects on osteoclasts and support the colonization and viability of osteoblasts. The expressions of Alkaline Phosphatase (ALPL), collagen type I alpha 1 chain (COL1A1), and osteocalcin (BGLAP) suggest that curcumin reduces the osteoblast differentiation state but yields encouraging osteoprotegerin/receptor activator for the NFkB factor ligand (OPG/RANKL) ratio.

Hydrogel Drug Delivery Systems for Bone Regeneration

With the in-depth understanding of bone regeneration mechanisms and the development of bone tissue engineering, a variety of scaffold carrier materials with desirable physicochemical properties and biological functions have recently emerged in the field of bone regeneration. Hydrogels are being increasingly used in the field of bone regeneration and tissue engineering because of their biocompatibility, unique swelling properties, and relative ease of fabrication. Hydrogel drug delivery systems comprise cells, cytokines, an extracellular matrix, and small molecule nucleotides, which have different properties depending on their chemical or physical cross-linking. Additionally, hydrogels can be designed for different types of drug delivery for specific applications. In this paper, we summarize recent research in the field of bone regeneration using hydrogels as delivery carriers, detail the application of hydrogels in bone defect diseases and their mechanisms, and discuss future research directions of hydrogel drug delivery systems in bone tissue engineering.

Magnetic Gels in Skin Cancer Treatment: A Review of Potential Applications in Diagnostics, Drug Delivery and Hyperthermia

Skin cancer (SC) is affecting an increasing number of people worldwide. Its lesions affect mainly the most exposed regions of the skin. SC is classified into to main categories: non-melanoma (basal cell carcinoma of the epidermis and squamous cell carcinoma) and melanoma (the abnormal proliferation of melanocytes, which is rarer, more hazardous, and more deadly). Prevention and early diagnosis are important actions, and surgery is often considered. After the removal of cancerous lesions, the local administration of medicine can guarantee anticancer therapeutic action, rapid healing and the recovery of tissue, ensuring the absence of recurrence. Magnetic gels (MGs) have attracted increased attention regarding their pharmaceutical and biomedical applications. They are magnetic nanoparticles (e.g., iron oxide nanoparticles) dispersed in a polymeric matrix, which constitute adaptive systems under a magnetic field. MGs can combine magnetic susceptibility, high elasticity, and softness, and are thus useful platforms for diagnostics, drug delivery, and also for hyperthermia. This manuscript reviews MGs as a technological strategy for the treatment of SC. An overview of SC and the treatment, types, and methods of preparing MGs are discussed. Moreover, the applications of MGs in SC and their future perspectives are considered. The combination of polymeric gels and magnetic nanoparticles continues to be investigated, and new products must hit the market. Clinical trials and new products are expected, due to the important advantages of MGs.

Cell-Penetrating Peptidic GRP78 Ligand-Conjugated Iron Oxide Magnetic Nanoparticles for Tumor-Targeted Doxorubicin Delivery and Imaging

Although chemotherapy is regarded as an essential option in cancer treatment, it is still far from being perfect. Inadequate tumor drug concentration and systemic toxicity along with broad biodistribution have diminished the utility of chemotherapy. Tumor-targeting peptide-conjugated multifunctional nanoplatforms have emerged as an effective strategy for site-directed tumor tissues in cancer treatment and imaging. Herein, Pep42-targeted iron oxide magnetic nanoparticles (IONPs) functionalized with β-cyclodextrin (ßCD) containing doxorubicin (DOX) (Fe₃O₄-ßCD-Pep42-DOX) were successfully developed. The physical effects of the prepared NPs were characterized by employing various techniques. Transmission electron microscopy (TEM) images disclosed that the developed Fe₃O₄-ßCD-Pep42-DOX nanoplatforms had a spherical morphology and a core-shell structure with a size of nearly 17 nm. Fourier transform infrared (FT-IR) spectroscopy showed that β-cyclodextrin, DOX, and Pep42 molecules were successfully loaded on the IONPs. In vitro cytotoxicity analysis revealed that the fabricated multifunctional Fe₃O₄-ßCD-Pep42 nanoplatforms possessed excellent biosafety toward BT-474, MDA-MB468 (cancerous cells), and MCF10A normal cells, while Fe₃O₄-ßCD-Pep42-DOX exhibited great cancer cell killing ability. The high cellular uptake along with intracellular trafficking of Fe₃O₄-ßCD-Pep42-DOX highlights the usefulness of the Pep42-targeting peptide. In vivo results strongly supported the in vitro results, i.e., significant tumor size reduction was observed by single-dose injection of Fe₃O₄-ßCD-Pep42-DOX into tumor-bearing mice. Interestingly, in vivo MR imaging (MRI) of Fe₃O₄-ßCD-Pep42-DOX revealed T₂ contrast improvement in the tumor cells and therapeutic ability in cancer theranostics. Taken together, these findings provided strong evidence for the potential capability of Fe₃O₄-ßCD-Pep42-DOX as a multifunctional nanoplatform in cancer therapy and imaging and opens up a new avenue of research in this area.

Next-Generation Hydrogels as Biomaterials for Biomedical Applications: Exploring the Role of Curcumin

Since the first report on the pharmacological activity of curcumin in 1949, enormous amounts of research have reported diverse activities for this natural polyphenol found in the dietary spice turmeric. However, curcumin has not yet been used for human application as an approved drug. The clinical translation of curcumin has been hampered due to its low solubility and bioavailability. The improvement in bioavailability and solubility of curcumin can be achieved by its formulation using drug delivery systems. Hydrogels with their biocompatibility and low toxicity effects have shown a substantial impact on the successful formulation of hydrophobic drugs for human clinical trials. This review focuses on hydrogel-based delivery systems for curcumin and describes its applications as anti-cancer as well as wound healing agents.

The Differential Antagonistic Ability of Curcumin against Cytotoxicity and Genotoxicity Induced by Distinct Heavy Metals

Widespread heavy metal pollution has aroused severe health risks worldwide. Curcumin has been reported to play a wide-spectrum protective role for various heavy metals. However, the specificity and difference in the antagonistic ability of curcumin against distinct types of heavy metals are still largely unknown. Here, using cadmium (Cd), arsenic (As), lead (Pb), and nickel (Ni) as the typical heavy metals, we systematically compared the detoxification efficiency of curcumin on the cytotoxicity and genotoxicity elicited by different heavy metals under the same experimental conditions. Curcumin was proved to have a significant discrepant antagonistic capacity when counteracting the adverse effect of different heavy metals. Stronger protective effects of curcumin emerged when antagonizing the toxicity of Cd and As, rather than Pb and Ni. Curcumin exhibits a better detoxification ability against heavy metal-induced genotoxicity than cytotoxicity. Mechanistically, inhibiting the oxidative stress elicited by heavy metals and reducing the bioaccumulation of metal ions both contributed to the detoxification of curcumin against all the tested heavy metals. Our results illustrated that curcumin shows prominent detoxification specificity against different types of heavy metals and toxic endpoints, which provides a new clue for the better and targeted application of curcumin in heavy metal detoxification.

Nanocomposite multifunctional hyaluronic acid hydrogel with photothermal antibacterial and antioxidant properties for infected wound healing

Bacterial infection and subsequent reactive oxygen species (ROS) damage are major factors that delay wound healing in infected skin. Recently, photothermal therapy (PTT), as a new antibacterial method, has shown great advantages in the treatment of infected skin wound. Antibacterial and antioxidant hydrogels can reduce bacterial colonization and infection, scavenge ROS, relieve inflammation, and accelerate wound healing. In this study, an enzyme-crosslinked hyaluronic acid-tyramine (HT) hydrogel loaded with antioxidant and photothermal silver nanoparticles (AgNPs), named HTA, was developed as functional wound dressing to promote the infected skin wound healing. Natural antioxidant tannic acids (TA) were used as both reducing and stabilizing agents to facilely synthesize the silver nanoparticles capped with TA (AgNPs@TA). The incorporation of AgNPs@TA significantly enhanced the antioxidant, antibacterial, photothermal antibacterial, adhesive, and hemostatic abilities of the resulted HTA hydrogel. Besides, HTA hydrogel has rapid gelation, well injection and biocompatibility. In vivo results on the Staphylococcus aureus and Escherichia coli co-infected mouse skin wound model showed that HTA_0.4 (containing 0.4 mg/mL AgNPs@TA) hydrogel combined with near infrared ray radiation highly alleviated inflammation, promoted angiogenesis, and accelerated the healing process. Therefore, this nanocomposite hydrogel wound dressing with antibacterial and antioxidant capabilities has great application potential in the treatment of infected skin wounds.

Remotely Temporal Scheduled Macrophage Phenotypic Transition Enables Optimized Immunomodulatory Bone Regeneration

Precise timing of macrophage polarization plays a pivotal role in immunomodulation of tissue regeneration, yet most studies mainly focus on M2 macrophages for their anti-inflammatory and regenerative effects while the essential proinflammatory role of the M1 phenotype on the early inflammation stage is largely underestimated. Herein, a superparamagnetic hydrogel capable of timely controlling macrophage polarization is constructed by grafting superparamagnetic nanoparticles on collagen nanofibers. The magnetic responsive hydrogel network enables efficient polarization of encapsulated macrophage to the M2 phenotype through the podosome/Rho/ROCK mechanical pathway in response to static magnetic field (MF) as needed. Taking advantage of remote accessibility of magnetic field together with the superparamagnetic hydrogels, a temporal engineered M1 to M2 transition course preserving the essential role of M1 at the early stage of tissue healing, as well as enhancing the prohealing effect of M2 at the middle/late stages is established via delayed MF switch. Such precise timing of macrophage polarization matching the regenerative process of injured tissue eventually leads to optimized immunomodulatory bone healing in vivo. Overall, this study offers a remotely time-scheduled approach for macrophage polarization, which enables precise manipulation of inflammation progression during tissue healing.

Nanocrystalline Yttria-Stabilized Zirconia Ceramics for Cranial Window Applications

Transparent yttria-stabilized zirconia (YSZ) ceramics are promising for cranial window applications because of their good mechanical and optical properties as well as biocompatibility. YSZ discs with different yttria concentrations were either processed via current-activated pressure-assisted densification (CAPAD) using commercial nanoparticles or densified via spark plasma sintering (SPS) using pyrolysis-synthesized nanoparticles in-house. This study provided critical results to screen composition, processing, microstructure, and cytocompatibility of transparent YSZ discs for cranial window applications. CAPAD-processed YSZ discs with 6 or 8 mol % yttria (6YSZ and 8YSZ) and SPS-densified YSZ discs with 4 mol % yttria (4YSZ_P) showed 200-350 nm polycrystalline grains containing 20-30 nm crystallite domains. SPS-densified YSZ discs with 8 mol % yttria (8YSZ_P) showed larger polycrystalline grains of 819 ± 155 nm with 29 ± 5 nm crystallite domains. CAPAD-processed YSZ discs with 3 mol % yttria (3YSZ) showed 39 ± 9 nm grains. Bone-marrow-derived stem cells (BMSCs) on the polished YSZ discs showed statistically higher spreading areas than those on the unpolished YSZ discs of the same compositions. Generally, polished 8YSZ, 4YSZ_P, and 8YSZ_P discs and unpolished 8YSZ_R, 4YSZ_PR, and 8YSZ_PR discs had lower average cell adhesion densities than other YSZ discs under direct contact conditions. Under indirect contact conditions, all the YSZ disc groups showed similar average cell adhesion densities to the Cell-only control. The groups of polished 4YSZ_P and 8YSZ_P discs, unpolished 4YSZ_PR and 8YSZ_PR discs, and particle control of 8YSZ_Pnp showed higher Y³⁺ ion concentrations than other groups. No mineral deposition was detected on the polished YSZ discs after cell culture. Considering multiple factors such as cytocompatibility, cell adhesion density, Y³⁺ ion release, mineral deposition, and optical transparency collectively, 8YSZ may be the best candidate for the cranial window applications. Further studies are needed to evaluate the long-term transparency and biocompatibility of YSZ discs.