Plasma-Enabled Graphene Quantum Dot Hydrogel-Magnesium Composites as Bioactive Scaffolds for In Vivo Bone Defect Repair

Cerium-Organic Framework and Resveratrol Composite Hydrogel Scaffold with Dual Antioxidant Activity for Enhanced Bone Regeneration

The repair of large bone defects remains a significant challenge in the field of orthopedics, as traditional bone substitutes face issues such as limited supply and structural incompatibility. Therefore, the development of novel biomaterials to promote bone repair is of great significance. This study proposes a composite material based on a gelatin/alginate dual-network hydrogel scaffold (Gel/AlgMA), which regulates oxidative stress in the local microenvironment of bone defects by loading cerium metal-organic frameworks (Ce-UiO-66) and resveratrol (Res). The cerium ions in Ce-UiO-66 exhibit excellent antioxidant properties in their multivalent states, capable of scavenging excess reactive oxygen species (ROS), improving mitochondrial function, and enhancing stability through a polydopamine (PDA) coating. The Gel/Alg@Ce-Res/PDA composite scaffold was prepared via photopolymerization and its in vitro biocompatibility, antioxidant properties, and osteogenic potential were evaluated. The results indicated that the composite scaffold effectively scavenged ROS, alleviated oxidative stress, and promoted the proliferation and differentiation of osteoblasts. Moreover, in vivo experiments further confirmed the favorable effects of the Gel/Alg@Ce-Res/PDA scaffold in bone defect repair. This study provides an innovative biomaterial design for bone defect treatment, with promising clinical application prospects.

Covalent Peptide-Graphene Conjugates for Enhanced Cell Spreading, Osteogenic Differentiation, and Angiogenesis in Bone Defects

Traumatic bone injury is one of the most common injuries that require surgical intervention, and current treatments suffer severe drawbacks. Modern research in bone regeneration focuses on implants that will support and enhance native tissue regeneration. One scaffold material that shows promise is graphene oxide (GO), a 2D nanomaterial made from oxidation of graphite. GO is biocompatible, strong, osteoinductive, is safely and slowly resorbed by the body, has a cheap, facile, and scalable synthesis, and is highly tailorable and functionalizable. The bioactivity of GO can be enhanced via functionalization with biomolecules such as peptides, proteins, and small molecules. Here, short peptides RGD, DGEA, and KKGHK are covalently bound to GO through a Claisen modification (CG) to create new functional graphenic materials that are cell-adhesive, osteogenic, and angiogenic, respectively. These peptide-Claisen graphenes (peptide-CGs) are found to be cytocompatible, to encourage cell spreading on the graphenic surface, to promote osteogenesis in stem cells, and to induce angiogenesis in vascular endothelial cells. They show promise as next-generation bone regeneration scaffolds by overcoming challenges frequently faced by bone regeneration scaffolds, namely retaining implanted and recruited cells, promoting their survival, proliferation, and differentiation, and ensuring a sufficient oxygen and nutrient supply to new tissue.

Integration of Graphene into Calcium Phosphate Coating for Implant Electronics

Bone injuries remain a significant challenge, driving the development of new materials and technologies to enhance healing. This study presents a novel approach for incorporating graphene into calcium phosphate (CaP) coatings on titanium alloy (Ti) substrates, with the aim of creating a new generation of materials for bone implant electronics. The stability of the composite coating under physiological conditions, long-term electrical and mechanical durability, and biocompatibility were systematically investigated. We integrated graphene into the CaP coating through the laser processing of diazonium-functionalized graphene films applied to the surface of CaP-coated Ti. The laser treatment induced several processes, including the removal of aryl groups, the formation of conductive pathways, and chemical bonding with the CaP film. As a result, the graphene-CaP nanocomposite demonstrated excellent mechanical durability, withstanding a 2 h sand abrasion test. It also exhibited excellent biocompatibility, as shown by the proliferation of human fibroblast cells for 7 days. The electrical properties remained stable under physiological conditions for 12 weeks, and the material maintained electrochemical stability after 1 million pulse cycles. Furthermore, it withstood the stress of 100,000 bending cycles without compromising electrical performance. This work highlights the versatility of the biocompatible graphene composite and its potential for a range of applications including free-form electronic circuits, electrodes, bending sensors, and electrothermal heaters.

Biomimetic Hydrogels - Tools for Regenerative Medicine, Oncology, and Understanding Medical Gas Plasma Therapy

Biomimetic hydrogels enable biochemical, cell biology, and tissue-like studies in the third dimension. Smart hydrogels are also frequently used in tissue engineering and as drug carriers for intra- or extracutaneous regenerative medicine. They have also been studied in bio-sensor development, 3D cell culture, and organoid growth optimization. Yet, many hydrogel types, adjuvant components, and cross-linking methods have emerged over decades, diversifying and complexifying such studies. Here, an evaluative overview is provided, mapping potential applications to the corresponding hydrogel tuning. Strikingly, hydrogels are ideal for studying locoregional therapy modalities, such as cold medical gas plasma technology. These partially ionized gases produce various reactive oxygen species (ROS) types along with other physico-chemical components such as ions and electric fields, and the spatio-temporal effects of these components delivered to diseased tissues remain largely elusive to date. Hence, this work outlines the promising applications of hydrogels in biomedical research in general and cold plasma science in particular and underlines the great potential of these smart scaffolds for current and future research and therapy.

A Cascaded Chip for the High-Purity Capture and Distinguishing Detection of Phenotypic Circulating Tumor Cells in Colon Cancer

The low abundance, complex phenotypes, and need for sophisticated blood preprocessing pose substantial obstacles to the clinical implementation of circulating tumor cells (CTCs). Herein, we constructed a cascaded PMMA chip-based platform for the separation of CTCs from other cells within blood samples, as well as distinguishing the detection of epithelial and mesenchymal CTCs. The primary physical separation chip (PS-Chip) focused and sorted CTCs from whole blood via Dean flow fractionation (DFF) according to size differences between CTCs and other blood cells, being capable of eliminating approximately 93.7% of red blood cells (RBCs) and 68.4% of white blood cells (WBCs) from whole blood while maintaining a CTC recovery rate of around 90%. Subsequently, to further purify the isolated CTCs in the upstream, a partitioned immunoaffinity capture and detection chip (PICD-Chip) featuring with two independent chambers (Zone 1, Zone 2) was designed, each of which was premodified with Gel-GO/E/V-Apt complexes that specifically recognize CTCs with distinct phenotypes, enabling further separation of residual blood cells from the upstream isolation. Upon the subsequent introduction of two detection probes, namely EpCAM and vimentin aptamer-modified mesoporous Pt nanoparticles (mPtNPs/E/V-Apt), into Zone 1 and Zone 2, respectively, heterogeneous CTCs ranging from 5 to 200/mL captured within two chambers were distinguished and quantified utilizing the exceptional peroxidase activity of mPtNPs. The integrated approach of efficient enrichment and differentiation detection of phenotypic CTCs under the requirement of high purity has enabled the successful application of the cascaded chip in the diagnosis of colon cancer patients at different stages.

Synergistic effects of platelet-rich fibrin and photobiomodulation on bone regeneration in MC3T3-E1 Preosteoblasts

BACKGROUND

Platelet-rich fibrin (PRF) and Photobiomodulation (PBM) are established methods for promoting bone healing. PRF enhances cell proliferation and migration due to its rich concentration of growth factors, while PBM stimulates tissue repair through mitochondrial activation. Despite their efficacies, no in-depth studies have explored the synergistic effects of combining PRF and PBM.

METHODS

PRF was prepared at 50 % and 100 % concentrations, and PBM was applied using an 830 nm near-infrared laser at a dose of 5 J/cm². Cell viability, migration, and calcium deposition were assessed over seven and fourteen days.

RESULTS

The combination of PRF and PBM significantly improved cell viability, migration, and calcium deposition, with the most notable effects observed after seven and fourteen days. However, a slight decrease in calcium deposition was noted in the 100 % PRF combined with the PBM group, suggesting a potential feedback mechanism at higher PRF concentrations.

CONCLUSIONS

This study explores the synergistic effects of PRF and PBM, offering new insights into optimizing bone tissue engineering strategies. The findings highlight the potential of this combined approach in enhancing bone regeneration, although further research is needed to refine the optimal conditions for these therapies.

Honeycomb Bionic Graphene Oxide Quantum Dot/Layered Double Hydroxide Composite Nanocoating Promotes Osteoporotic Bone Regeneration via Activating Mitophagy

Abnormal osteogenic and remodeling microenvironment due to osteoblast apoptosis are the primary causes of delayed fracture healing in osteoporotic patients. Magnesium (Mg) alloys exhibit biodegradability and appropriate elastic moduli for bone defects in osteoporosis, but the effect on the local bone remodeling disorder is still insufficient. Inspired by the "honeycomb," layered double hydroxide (LDH) with regular traps with graphene oxide quantum dots (GOQDs) inlayed is constructed by pulsed electrodeposition to generate GOQD/LDH composite nanocoatings on the surfaces of Mg alloy substrates. The honeycomb bionic multi-layer stereoscopic structure shows good regulation of the degradation of Mg alloy for the support of healing time required for osteoporotic bone defect. Within its lattice, the local microenvironment conducive to osteogenesis is provided by both the rescue effect of GOQD and LDH. The osteoblast apoptosis is rescued due to the activation of mitophagy to clear dysfunctional mitochondria, where the upregulation of BNIP3 phosphorylation played a key role. The osteoporotic rat model of femoral defects confirmed the improvement of bone regeneration and osseointegration of GOQD/LDH coating. In summary, honeycomb bionic composite nanocoatings with controllable degradation and excellent pro-osteogenic performance demonstrated a promising design strategy on Mg alloy implants in the therapy of osteoporotic bone defects.

Quantum dots for bone tissue engineering

In confronting the global prevalence of bone-related disorders, bone tissue engineering (BTE) has developed into a critical discipline, seeking innovative materials to revolutionize treatment paradigms. Quantum dots (QDs), nanoscale semiconductor particles with tunable optical properties, are at the cutting edge of improving bone regeneration. This comprehensive review delves into the multifaceted roles that QDs play within the realm of BTE, emphasizing their potential to not only revolutionize imaging but also to osteogenesis, drug delivery, antimicrobial strategies and phototherapy. The customizable nature of QDs, attributed to their size-dependent optical and electronic properties, has been leveraged to develop precise imaging modalities, enabling the visualization of bone growth and scaffold integration at an unprecedented resolution. Their nanoscopic scale facilitates targeted drug delivery systems, ensuring the localized release of therapeutics. QDs also possess the potential to combat infections at bone defect sites, preventing and improving bacterial infections. Additionally, they can be used in phototherapy to stimulate important bone repair processes and work well with the immune system to improve the overall healing environment. In combination with current trendy artificial intelligence (AI) technology, the development of bone organoids can also be combined with QDs. While QDs demonstrate considerable promise in BTE, the transition from laboratory research to clinical application is fraught with challenges. Concerns regarding the biocompatibility, long-term stability of QDs within the biological environment, and the cost-effectiveness of their production pose significant hurdles to their clinical adoption. This review summarizes the potential of QDs in BTE and highlights the challenges that lie ahead. By overcoming these obstacles, more effective, efficient, and personalized bone regeneration strategies will emerge, offering new hope for patients suffering from debilitating bone diseases.

Development and evaluation of an injectable ChitHCl-MgSO4-DDA hydrogel for bone regeneration: In vitro and in vivo studies on cell migration and osteogenesis enhancement

Nonunion and delayed union of the bone are situations in orthopedic surgery that can occur even if the bone alignment is correct and there is sufficient mechanical stability. Surgeons usually apply artificial bone grafts in bone fracture gaps or in bone defect sites for osteogenesis to improve bone healing; however, these bone graft materials have no osteoinductive or osteogenic properties, and fit the morphology of the fracture gap with difficulty. In this study, we developed an injectable chitosan-based hydrogel with MgSO4 and dextran oxidative, with the purpose to improve bone healing through introducing an engineered chitosan-based hydrogel. The developed hydrogel can gelate and fit with any morphology or shape, has good biocompatibility, can enhance the cell-migration capacity, and can improve extracellular calcium deposition. Moreover, the amount of new bone formed by injecting the hydrogel in the bone tunnel was assessed by an in vivo test. We believe this injectable chitosan-based hydrogel has great potential for application in the orthopedic field to improve fracture gap healing.

Hydrogel loaded with thiolated chitosan modified taxifolin liposome promotes osteoblast proliferation and regulates Wnt signaling pathway to repair rat skull defects

To alleviate skull defects and enhance the biological activity of taxifolin, this study utilized the thin-film dispersion method to prepare paclitaxel liposomes (TL). Thiolated chitosan (CSSH)-modified TL (CTL) was synthesized through charge interactions. Injectable hydrogels (BLG) were then prepared as hydrogel scaffolds loaded with TAX (TG), TL (TLG), and CTL (CTLG) using a Schiff base reaction involving oxidized dextran and carboxymethyl chitosan. The study investigated the bone reparative properties of CTLG through molecular docking, western blot techniques, and transcriptome analysis. The particle sizes of CTL were measured at 248.90 ± 14.03 nm, respectively, with zeta potentials of +36.68 ± 5.43 mV, respectively. CTLG showed excellent antioxidant capacity in vitro. It also has a good inhibitory effect on Escherichia coli and Staphylococcus aureus, with inhibition rates of 93.88 ± 1.59 % and 88.56 ± 2.83 % respectively. The results of 5-ethynyl-2 '-deoxyuridine staining, alkaline phosphatase staining and alizarin red staining showed that CTLG also had the potential to promote the proliferation and differentiation of mouse embryonic osteoblasts (MC3T3-E1). The study revealed that CTLG enhances the expression of osteogenic proteins by regulating the Wnt signaling pathway, shedding light on the potential application of TAX and bone regeneration mechanisms.