Continuous release of bone morphogenetic protein-2 through nano-graphene oxide-based delivery influences the activation of the NF-κB signal transduction pathway

Graphene Oxide Nanostructures as Nanoplatforms for Delivering Natural Therapeutic Agents: Applications in Cancer Treatment, Bacterial Infections, and Bone Regeneration Medicine

Graphene, fullerenes, diamond, carbon nanotubes, and carbon dots are just a few of the carbon-based nanomaterials that have gained enormous popularity in a variety of scientific disciplines and industrial uses. As a two-dimensional material in the creation of therapeutic delivery systems for many illnesses, nanosized graphene oxide (NGO) is now garnering a large amount of attention among these materials. In addition to other benefits, NGO functions as a drug nanocarrier with remarkable biocompatibility, high pharmaceutical loading capacity, controlled drug release capability, biological imaging efficiency, multifunctional nanoplatform properties, and the power to increase the therapeutic efficacy of loaded agents. Thus, NGO is a perfect nanoplatform for the development of drug delivery systems (DDSs) to both detect and treat a variety of ailments. This review article's main focus is on investigating surface functionality, drug-loading methods, and drug release patterns designed particularly for smart delivery systems. The paper also examines the relevance of using NGOs to build DDSs and considers prospective uses in the treatment of diseases including cancer, infection by bacteria, and bone regeneration medicine. These factors cover the use of naturally occurring medicinal substances produced from plant-based sources.

Strategies of immobilizing BMP-2 with 3D-printed scaffolds to improve osteogenesis

The management and definitive treatment of critical-size bone defects in severe trauma, tumor resection and congenital malformation are troublesome for orthopedic surgeons and patients worldwide without recognized good treatment strategies. Researchers and clinicians are working to develop new strategies to treat these problems. This review aims to summarize the techniques used by additive manufacturing scaffolds loaded with BMP-2 to promote osteogenesis and to analyze the current status and trends in relevant clinical translation. Optimize composite scaffold design to enhance bone regeneration through printing technology, material selection, structure design and loading methods of BMP-2 to advance the clinical therapeutic bone repair field.

The Delivery and Activation of Growth Factors Using Nanomaterials for Bone Repair

Bone regeneration is a comprehensive process that involves different stages, and various growth factors (GFs) play crucial roles in the entire process. GFs are currently widely used in clinical settings to promote bone repair; however, the direct application of GFs is often limited by their fast degradation and short local residual time. Additionally, GFs are expensive, and their use may carry risks of ectopic osteogenesis and potential tumor formation. Nanomaterials have recently shown great promise in delivering GFs for bone regeneration, as they can protect fragile GFs and control their release. Moreover, functional nanomaterials can directly activate endogenous GFs, modulating the regeneration process. This review provides a summary of the latest advances in using nanomaterials to deliver exogenous GFs and activate endogenous GFs to promote bone regeneration. We also discuss the potential for synergistic applications of nanomaterials and GFs in bone regeneration, along with the challenges and future directions that need to be addressed.

A Novel Zwitterionic Hydrogel Incorporated with Graphene Oxide for Bone Tissue Engineering: Synthesis, Characterization, and Promotion of Osteogenic Differentiation of Bone Mesenchymal Stem Cells

Zwitterionic materials are widely applied in the biomedical field due to their excellent antimicrobial, non-cytotoxicity, and antifouling properties but have never been applied in bone tissue engineering. In this study, we synthesized a novel zwitterionic hydrogel incorporated with graphene oxide (GO) using maleic anhydride (MA) as a cross-linking agent by grafted L-cysteine (L-Cys) as the zwitterionic material on maleilated chitosan via click chemistry. The composition and each reaction procedure of the novel zwitterionic hydrogel were characterized via X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FT-IR), while the morphology was imaged by scanning electron microscope (SEM). In vitro cell studies, CCK-8 and live/dead assay, alkaline phosphatase activity, W-B, and qRT-CR tests showed zwitterionic hydrogel incorporated with GO remarkably enhanced the osteogenic differentiation of bone mesenchymal stem cells (BMSCs); it is dose-dependent, and 2 mg/mL GO is the optimum concentration. In vivo tests also indicated the same results. Hence, these results suggested the novel zwitterionic hydrogel exhibited porous characteristics similar to natural bone tissue. In conclusion, the zwitterionic scaffold has highly biocompatible and mechanical properties. When GO was incorporated in this zwitterionic scaffold, the zwitterionic scaffold slows down the release rate and reduces the cytotoxicity of GO. Zwitterions and GO synergistically promote the proliferation and osteogenic differentiation of rBMSCs in vivo and in vitro. The optimal concentration is 2 mg/mL GO.

3D-Printing Graphene Scaffolds for Bone Tissue Engineering

Graphene-based materials have recently gained attention for regenerating various tissue defects including bone, nerve, cartilage, and muscle. Even though the potential of graphene-based biomaterials has been realized in tissue engineering, there are significantly many more studies reporting in vitro and in vivo data in bone tissue engineering. Graphene constructs have mainly been studied as two-dimensional (2D) substrates when biological organs are within a three-dimensional (3D) environment. Therefore, developing 3D graphene scaffolds is the next clinical standard, yet most have been fabricated as foams which limit control of consistent morphology and porosity. To overcome this issue, 3D-printing technology is revolutionizing tissue engineering, due to its speed, accuracy, reproducibility, and overall ability to personalize treatment whereby scaffolds are printed to the exact dimensions of a tissue defect. Even though various 3D-printing techniques are available, practical applications of 3D-printed graphene scaffolds are still limited. This can be attributed to variations associated with fabrication of graphene derivatives, leading to variations in cell response. This review summarizes selected works describing the different fabrication techniques for 3D scaffolds, the novelty of graphene materials, and the use of 3D-printed scaffolds of graphene-based nanoparticles for bone tissue engineering.

Genetic profiling of human bone marrow and adipose tissue-derived mesenchymal stem cells reveals differences in osteogenic signaling mediated by graphene

BACKGROUND

In the last decade, graphene surfaces have consistently supported osteoblast development of stem cells, holding promise as a therapeutic implant for degenerative bone diseases. However, until now no study has specifically examined the genetic changes when stem cells undergo osteogenic differentiation on graphene.

RESULTS

In this study, we provide a detailed overview of gene expressions when human mesenchymal stem cells (MSCs) derived from either adipose tissue (AD-MSCs) or bone marrow (BM-MSCs), are cultured on graphene. Genetic expressions were measured using osteogenic RT² profiler PCR arrays and compared either over time (7 or 21 days) or between each cell source at each time point. Genes were categorized as either transcriptional regulation, osteoblast-related, extracellular matrix, cellular adhesion, BMP and SMAD signaling, growth factors, or angiogenic factors. Results showed that both MSC sources cultured on low oxygen graphene surfaces achieved osteogenesis by 21 days and expressed specific osteoblast markers. However, each MSC source cultured on graphene did have genetically different responses. When compared between each other, we found that genes of BM-MSCs were robustly expressed, and more noticeable after 7 days of culturing, suggesting BM-MSCs initiate osteogenesis at an earlier time point than AD-MSCs on graphene. Additionally, we found upregulated angiogenic markers in both MSCs sources, suggesting graphene could simultaneously attract the ingrowth of blood vessels in vivo. Finally, we identified several novel targets, including distal-less homeobox 5 (DLX5) and phosphate-regulating endopeptidase homolog, X-linked (PHEX).

CONCLUSIONS

Overall, this study shows that graphene genetically supports differentiation of both AD-MSCs and BM-MSCs but may involve different signaling mechanisms to achieve osteogenesis. Data further demonstrates the lack of aberrant signaling due to cell-graphene interaction, strengthening the application of specific form and concentration of graphene nanoparticles in bone tissue engineering.

Targeted treatment for osteoarthritis: drugs and delivery system

The management of osteoarthritis (OA) is a clinical challenge due to the particular avascular, dense, and occluded tissue structure. Despite numerous clinical reports and animal studies, the pathogenesis and progression of OA are still not fully understood. On the basis of traditional drugs, a large number of new drugs have been continuously developed. Intra-articular (IA) administration for OA hastens the development of targeted drug delivery systems (DDS). OA drugs modification and the synthesis of bioadaptive carriers contribute to a qualitative leap in the efficacy of IA treatment. Nanoparticles (NPs) are demonstrated credible improvement of drug penetration and retention in OA. Targeted nanomaterial delivery systems show the prominent biocompatibility and drug loading-release ability. This article reviews different drugs and nanomaterial delivery systems for IA treatment of OA, in an attempt to resolve the inconsonance between in vitro and in vivo release, and explore more interactions between drugs and nanocarriers, so as to open up new horizons for the treatment of OA.

Intra-Articular Injection of Umbilical Cord Mesenchymal Stem Cells Loaded With Graphene Oxide Granular Lubrication Ameliorates Inflammatory Responses and Osteoporosis of the Subchondral Bone in Rabbits of Modified Papain-Induced Osteoarthritis

AIM

This study is to investigate the effects of umbilical cord mesenchymal stem cells (UCMSCs) loaded with the graphene oxide (GO) granular lubrication on ameliorating inflammatory responses and osteoporosis of the subchondral bone in knee osteoarthritis (KOA) animal models.

METHODS

The KOA animal models were established using modified papain joint injection. 24 male New Zealand rabbits were classified into the blank control group, GO group, UCMSCs group, and GO + UCMSCs group, respectively. The concentration in serum and articular fluid nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), type II collagen (COL-II), and glycosaminoglycan (GAG) was detected using ELISA, followed by the dissection of femoral condyles and staining of HE and Micro-CT for observation via the microscope.

RESULTS

GO granular lubrication and UCMSCs repaired the KOA animal models. NO, IL-6, TNF-α, GAG, and COL-II showed optimal improvement performance in the GO + UCMSCs group, with statistical significance in contrast to the blank group (P <0.01). Whereas, there was a great difference in levels of inflammatory factors in serum and joint fluid. Micro-CT scan results revealed the greatest efficacy of the GO + UCMSCs group in improving joint surface damage and subchondral bone osteoporosis. HE staining pathology for femoral condyles revealed that the cartilage repair effect in GO + UCMSCs, UCMSCs, GO, and blank groups were graded down.

CONCLUSION

UCMSCs loaded with graphene oxide granular lubrication can promote the secretion of chondrocytes, reduce the level of joint inflammation, ameliorate osteoporosis of the subchondral bone, and facilitate cartilage repair.

A Comprehensive Insight Towards Pharmaceutical Aspects of Graphene Nanosheets

Graphene Derivatives (GDs) have captured the interest and imagination of pharmaceutical scientists. This review exclusively provides pharmacokinetics and pharmacodynamics information with a particular focus on biopharmaceuticals. GDs can be used as multipurpose pharmaceutical delivery systems due to their ultra-high surface area, flexibility, and fast mobility of charge carriers. Improved effects, targeted delivery to tissues, controlled release profiles, visualization of biodistribution and clearance, and overcoming drug resistance are examples of the benefits of GDs. This review focuses on the application of GDs for the delivery of biopharmaceuticals. Also, the pharmacokinetic properties and the advantage of using GDs in pharmaceutics will be reviewed to achieve a comprehensive understanding about the GDs in pharmaceutical sciences.

Potential use of 3D-printed graphene oxide scaffold for construction of the cartilage layer

Background

Three-dimensional (3D) printing involves the layering of seed cells, biologically compatible scaffolds, and biological activity factors to precisely recapitulate a biological tissue. Graphene oxide (GO), a type of micro material, has been utilized as a small molecule-transport vehicle. With the proliferation of GO, the biocompatibility of chondrocytes in a microenvironment constructed by 3D printed scaffolds and GO is innovative. Accordingly, we speculate that, as a type of micro material, GO can be used with 3D scaffolds for a uniform distribution in the cartilage layer.

Results

A qualitative analysis of the chondrocyte-proliferation potential revealed that the culture of 3D printing with a 10% GO scaffold was higher than that of the other groups. Meanwhile, the progress of cell apoptosis was activated. Through scanning electron microscopy, immunofluorescence, and in vivo research, we observed that the newborn cartilage matrix extended along the border of the cartilage and scaffold and matured. After an analysis with immunohistochemical staining with aggrecan and collagen I, the cartilage following the 3D-printed scaffold was thinner than that of the 3D-printed GO scaffold. Furthermore, the collagen I of the cartilage expression in treatment with the GO scaffold was significant from week 2 to 6.

Conclusions

The findings indicate that a 3D-printed GO scaffold can potentially be utilized for the construction of a cartilage matrix. However, the optimum concentration of GO requires further research and discussion.

Hierarchically Porous Hydroxyapatite Hybrid Scaffold Incorporated with Reduced Graphene Oxide for Rapid Bone Ingrowth and Repair

Hydroxyapatite (HA), the traditional bone tissue replacement material was widely used in the clinical treatment of bone defects because of its excellent biocompatibility. However, the processing difficulty and poor osteoinductive ability greatly limit the application of HA. Although many strategies have been reported to improve the machinability and osteointegration ability, the performance including mechanical strength, porosity, cell adhesion, etc. of material still can not meet the requirements. In this work, a soft template method was developed and a porous scaffold with hierarchical pore structure, nano surface morphology, suitable porosity and pore size, and good biomechanical strength was successfully prepared. The hierarchical pore structure is beneficial for cell adhesion, fluid transfer, and cell ingrowth. Moreover, the loaded reduced graphene oxide (rGO) can improve the adhesion and promote the proliferation and spontaneous osteogenic differentiation bone marrow mesenchymal stem cells. The scaffold is then crushed, degraded and wrapped by the newly formed bone and the newly formed bone gradually replaces the scaffold. The degradation rate of the scaffold well matches the rate of the new bone formation. The hierarchical porous HA/rGO composite scaffolds can greatly accelerate the bone ingrowth in the scaffold and bone repair in critical bone defects, thus providing a clinical potential candidate for large segment bone tissue engineering.

Anti-HER2 functionalized graphene oxide as survivin-siRNA delivery carrier inhibits breast carcinoma growth in vitro and in vivo

BACKGROUND

The success of gene therapy is mostly dependent on the development of gene carrier. Graphene oxide (GO) possesses excellent aqueous solubility and biocompatibility, which is important for its biochemical and medical applications. Our previous work proved that GO can deliver siRNA into cells efficiently and downregulate the expression of desired protein.

METHODS

In this study, a novel delivery carrier, GO-R8/anti-HER2 (GRH), was developed by conjugating octaarginine (R8) and anti-HER2 antibody with GO as a tumor active-targeting vector for survivin-siRNA delivery.

RESULTS

GRH/survivin-siRNA formed nanoglobes of 195±10 nm in diameter. Real-time polymerase chain reaction analysis revealed that survivin messenger RNA expression showed a 42.4%±2.69% knockdown. The expression of survivin protein was downregulated to 50.86%±2.94% in enzyme-linked immunosorbent assay. In MTT tests, GRH exhibited no testable cytotoxicity. In vivo, GRH/survivin-siRNA showed gene silencing and inhibition of tumor growth.

CONCLUSION

The in vitro and in vivo results consistently demonstrated that GRH/survivin-siRNA has potential to be an efficient gene silencing carrier for siRNA delivery in cancer therapy.

Mussel-inspired graphene oxide nanosheet-enwrapped Ti scaffolds with drug-encapsulated gelatin microspheres for bone regeneration

Graphene oxide (GO) attracts considerable attention for biomedical applications owing to its unique nanostructure and remarkable physicochemical characteristics. However, it is challenging to uniformly deposit GO on chemically inert Ti scaffolds, which have good biocompatibility and wide applications in bone engineering. In this study, a GO-functionalized Ti porous scaffold (GO/Ti scaffold) was prepared by depositing GO onto polydopamine (PDA) modified Ti scaffolds. The mussel-inspired PDA modification facilitated the interaction between GO and Ti surfaces, leading to a uniform coverage of GO on Ti scaffolds. BMP2 and vancomycin (Van) were separately encapsulated into gelatin microspheres (GelMS). Then, drug-containing GelMS were assembled on GO/Ti scaffolds and anchored by the functional groups of GO. The modified scaffold independently delivered multiple biomolecules with different physiochemical properties, without interfering with each other. Thus, the GO/Ti scaffold has the dual functions of inducing bone regeneration and preventing bacterial infection. In summary, this mussel-inspired GO/Ti hybrid scaffold combined the good mechanical properties of Ti scaffolds and the advantages of GO nanosheets. GO nanosheets with their unique nanostructure and functional groups, together with GelMS on Ti scaffolds, are suitable carriers for drug delivery and provide adhesive sites for cell adhesion and create nanostructured environments for bone regeneration.

Multivalent Interactions between 2D Nanomaterials and Biointerfaces

2D nanomaterials, particularly graphene, offer many fascinating physicochemical properties that have generated exciting visions of future biological applications. In order to capitalize on the potential of 2D nanomaterials in this field, a full understanding of their interactions with biointerfaces is crucial. The uptake pathways, toxicity, long-term fate of 2D nanomaterials in biological systems, and their interactions with the living systems are fundamental questions that must be understood. Here, the latest progress is summarized, with a focus on pathogen, mammalian cell, and tissue interactions. The cellular uptake pathways of graphene derivatives will be discussed, along with health risks, and interactions with membranes-including bacteria and viruses-and the role of chemical structure and modifications. Other novel 2D nanomaterials with potential biomedical applications, such as transition-metal dichalcogenides, transition-metal oxide, and black phosphorus will be discussed at the end of this review.

Heparin-dopamine functionalized graphene foam for sustained release of bone morphogenetic protein-2

The recently developed three-dimensional (3D) graphene foam (GrF) is intriguing for potential bone tissue engineering applications because it provides stem cells with a 3D porous substrate for osteogenic differentiation. However, the nature of graphene's structure lacks functional groups, thus making it difficult for further modification such as immobilization or conjugation of growth factors, which are normally required to promote tissue regeneration. To explore the potential of GrF functionalization and sustained release of therapeutic proteins, we fabricated a modified 3D GrF scaffold with bio-inspired heparin-dopamine (Hepa-Dopa) molecules using a highly scalable chemical vapour deposition method. Our data indicated that Hepa-Dopa modification resulted in significantly higher bone morphogenetic protein-2 (BMP2) binding ability and longer release capacity compared with the untreated scaffolds. Importantly, the heparin-functionalized 3D GrF significantly improved the exogenous BMP2-induced osteogenic differentiation. Therefore, our study, for the first time, indicated that the 3D GrF can be biomimetically functionalized with Hepa-Dopa and be used for sustained release of BMP2, thereby inducing osteogenic differentiation and suggesting promising potential as a new multifunctional carrier for therapeutic proteins and stem cells in bone tissue engineering.

Successive Release of Tissue Inhibitors of Metalloproteinase-1 Through Graphene Oxide-Based Delivery System Can Promote Skin Regeneration

The purpose of this study was to testify the hypothesis that graphene oxide (GO) could act as an appropriate vehicle for the release of tissue inhibitors of metalloproteinase-1 (TIMP-1) protein in the context of skin repair. GO characteristics were observed by scanning electron microscopy, atomic force microscopy, and thermal gravimetric analysis. After TIMP-1 absorbing GO, the release profiles of various concentrations of TIMP-1 from GO were compared. GO biocompatibility with fibroblast viability was assessed by measuring cell cycle and apoptosis. In vivo wound healing assays were used to determine the effect of TIMP-1-GO on skin regeneration. The greatest intensity of GO was 1140 nm, and the most intensity volume was 10,674.1 nm (nanometer). TIMP-1 was shown to be continuously released for at least 40 days from GO. The proliferation and viability of rat fibroblasts cultured with TIMP-1-GO were not significantly different as compared with the cells grown in GO or TIMP-1 alone (p > 0.05). Skin defect of rats treated with TIMP-1 and TIMP-1-GO showed significant differences in histological and immunohistochemical scores (p < 0.05). GO can be controlled to release carrier materials. The combination of TIMP-1 and GO promoted the progression of skin tissue regeneration in skin defect.