Designing of macroporous magnetic bioscaffold based on functionalized methacrylate network covered by hydroxyapatites and doped with nano-MgFe 2 O 4 for potential cancer hyperthermia therapy

Targeting nanoplatform synergistic glutathione depletion-enhanced chemodynamic, microwave dynamic, and selective-microwave thermal to treat lung cancer bone metastasis

Once bone metastasis occurs in lung cancer, the efficiency of treatment can be greatly reduced. Current mainstream treatments are focused on inhibiting cancer cell growth and preventing bone destruction. Microwave ablation (MWA) has been used to treat bone tumors. However, MWA may damage the surrounding normal tissues. Therefore, it could be beneficial to develop a nanocarrier combined with microwave to treat bone metastasis. Herein, a microwave-responsive nanoplatform (MgFe2O4@ZOL) was constructed. MgFe2O4@ZOL NPs release the cargos of Fe3+, Mg2+ and zoledronic acid (ZOL) in the acidic tumor microenvironment (TME). Fe3+ can deplete intracellular glutathione (GSH) and catalyze H2O2 to generate •OH, resulting in chemodynamic therapy (CDT). In addition, the microwave can significantly enhance the production of reactive oxygen species (ROS), thereby enabling the effective implementation of microwave dynamic therapy (MDT). Moreover, Mg2+ and ZOL promote osteoblast differentiation. In addition, MgFe2O4@ZOL NPs could target and selectively heat tumor tissue and enhance the effect of microwave thermal therapy (MTT). Both in vitro and in vivo experiments revealed that synergistic targeting, GSH depletion-enhanced CDT, MDT, and selective MTT exhibited significant antitumor efficacy and bone repair. This multimodal combination therapy provides a promising strategy for the treatment of bone metastasis in lung cancer patients.

A Brief Review on Selected Applications of Hybrid Materials Based on Functionalized Cage-like Silsesquioxanes

Rapid developments in materials engineering are accompanied by the equally rapid development of new technologies, which are now increasingly used in various branches of our life. The current research trend concerns the development of methods for obtaining new materials engineering systems and searching for relationships between the structure and physicochemical properties. A recent increase in the demand for well-defined and thermally stable systems has highlighted the importance of polyhedral oligomeric silsesquioxane (POSS) and double-decker silsesquioxane (DDSQ) architectures. This short review focuses on these two groups of silsesquioxane-based materials and their selected applications. This fascinating field of hybrid species has attracted considerable attention due to their daily applications with unique capabilities and their great potential, among others, in biomaterials as components of hydrogel networks, components in biofabrication techniques, and promising building blocks of DDSQ-based biohybrids. Moreover, they constitute attractive systems applied in materials engineering, including flame retardant nanocomposites and components of the heterogeneous Ziegler-Natta-type catalytic system.

Novel hybrid composites based on double-decker silsesquioxanes functionalized by methacrylate derivatives and polyvinyl alcohol as potential materials utilized in biomedical applications

The use of diverse biomaterials for regenerative medicine is constantly evolving. Therefore, looking for easy-to-scale-up materials in terms of preparation, less complex composition, and featuring structural and chemical stability seems justified. In this work, we report the preparation of double-decker silsesquioxane-based (DDSQ-based) composites, which, according to our best knowledge, have never been used as biomaterials. A family of methacrylate-substituted DDSQs was obtained starting from the previously reported hydroxyalkyl double-decker silsesquioxanes. In the resulting hybrids, methacrylate groups are attached to each other's lateral silicon atoms of DDSQ in trans positions, providing an excellent geometry for forming thin layers. In contrast to pure organic methacrylates, the covalent bonding of methacrylate derivatives to inorganic silsesquioxane core improves mechanics, cell adhesion, and migration properties. Furthermore, to increase the hydrophilicity of the resulting DDSQ-based hybrids, polyvinyl alcohol (PVA) was added. The entire system forms an easy-to-obtain two-component (DDSQ-PVA) composite, which was subjected without any upgrading additives to biological tests later in the research. The resulting biomaterials fulfill the requirements for potential medical applications. Human fibroblasts growing on prepared hybrid composites are characterized by proper spindle-shaped morphology, proliferation, and activation status similar to control conditions (cells cultured on PVA), as well as increased adhesion and migration abilities. The obtained results suggest that the prepared biomaterials may be used in regenerative medicine in the future.

Baghdadite: A Novel and Promising Calcium Silicate in Regenerative Dentistry and Medicine

For several years, ceramic biomaterials have been extensively utilized to rebuild and substitute for body tissues. Calcium silicates have been proven to exhibit excellent bioactivity due to apatite formation and cell proliferation stimulation, in addition to degradability at levels adequate for hard tissue formation. These ceramics' excellent biological characteristics have attracted researchers. Baghdadite is a calcium silicate incorporating zirconium ions that enhances human osteoblast multiplication and development, increasing mineralization, and ossification. It has currently received much interest in academic institutions and has been extensively explored in the form of permeable frameworks, varnishes, bone adhesive and gap fillings, microparticles, and nanospheres, particularly in a wide range of biomedical applications. This review article aims to summarize and analyze the most recent research on baghdadite's mechanical characteristics, apatite-forming capability, dissolution pattern, and physiochemical qualities as a scaffold for dentofacial tissuè regeneration purposes.

The numerical study of pressure and temperature effects on mechanical properties of baghdadite-based nanostructure: molecular dynamics simulation

Bioceramics have been commonly implemented to replace and restore hard tissues such as teeth and bones in recent years. Among different bioceramics, Baghdadite (BAG) has high bioactivity due to its ability to form apatite and stimulate cell proliferation. So, this structure is used widely for medical applications to treat bone-based diseases. Physically, we expect changes in temperature and pressure to affect the Baghdadite-based nanostructure's mechanical behaviour. So, in this computational study, we report the pressure/temperature effect on Baghdadite matrix with nanoscale size by using Molecular Dynamics (MD) approach. To this end, physical values like the total energy, temperature, final strength (FS), stress-strain curve, potential energy, and Young's modulus (YM) are reported. Simulation results indicated the mechanical properties of Baghdadite (BAG) nanostructure weakened by temperature and pressure increase. Numerically, the FS and YM of the defined structure reach 131.40 MPa/159.43 MPa, and 115.15 MPa/139.72 MPa with temperature/pressure increasing. Therefore, the increase in initial pressure and temperature leads to a decrease in the mechanical properties of nanostructures. These results indicate the importance of the initial condition in the Baghdadite-based nanostructures' mechanical behaviour that must be considered in clinical applications.

Fiber-Templated 3D Calcium-Phosphate Scaffolds for Biomedical Applications: The Role of the Thermal Treatment Ambient on Physico-Chemical Properties

A successful bone-graft-controlled healing entails the development of novel products with tunable compositional and architectural features and mechanical performances and is, thereby, able to accommodate fast bone in-growth and remodeling. To this effect, graphene nanoplatelets and Luffa-fibers were chosen as mechanical reinforcement phase and sacrificial template, respectively, and incorporated into a hydroxyapatite and brushite matrix derived by marble conversion with the help of a reproducible technology. The bio-products, framed by a one-stage-addition polymer-free fabrication route, were thoroughly physico-chemically investigated (by XRD, FTIR spectroscopy, SEM, and nano-computed tomography analysis, as well as surface energy measurements and mechanical performance assessments) after sintering in air or nitrogen ambient. The experiments exposed that the coupling of a nitrogen ambient with the graphene admixing triggers, in both compact and porous samples, important structural (i.e., decomposition of β-Ca3(PO4)2 into α-Ca3(PO4)2 and α-Ca2P2O7) and morphological modifications. Certain restrictions and benefits were outlined with respect to the spatial porosity and global mechanical features of the derived bone scaffolds. Specifically, in nitrogen ambient, the graphene amount should be set to a maximum 0.25 wt.% in the case of compact products, while for the porous ones, significantly augmented compressive strengths were revealed at all graphene amounts. The sintering ambient or the graphene addition did not interfere with the Luffa ability to generate 3D-channels-arrays at high temperatures. It can be concluded that both Luffa and graphene agents act as adjuvants under nitrogen ambient, and that their incorporation-ratio can be modulated to favorably fit certain foreseeable biomedical applications.

Cobalt ferrite nanoparticles supported on reduced graphene oxide sheets: optical, magnetic and magneto-antibacterial studies

The development of antibacterial nanomaterials has emerged as a strategy to control bacterial activity, due to the growth and spread of antibiotic-resistant pathogen microorganisms. Graphene-based nanocarbons, as one of the most attractive materials, given their extraordinary physical and chemical properties, are promising candidate nanomaterials for biomedical applications. In this study, cobalt ferrite nanoparticles (NPs) supported on reduced graphene oxide (rGO) sheets to form metal nanocomposites (MNCs) known as CoFe₂O₄@rGO MNCs with different rGO contents (0, 10, 25 and 40 wt%) have been synthesized by a one-step process. The structures, morphology, optical, magnetic and antibacterial properties of the CoFe₂O₄@rGO were investigated by x-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy images, Raman, Fourier transform infrared (FTIR) and UV-Vis spectroscopies, vibration sample magnetometry and antibacterial tests as a function of rGO content. The particle sizes of the CoFe₂O₄ NPs supported on the different rGO contents were below 10 nm. The band gap energy of the samples decreased from about 3.1 to 1.7 eV with reducing rGO content. The results prove the effective reduction of graphene oxide to rGO and also the support of CoFe₂O₄ on rGO sheets by a one-step hydrothermal reaction. The increase in rGO content in the samples reduced their saturated magnetization from about 15 to 7 emu g^-1. The CoFe₂O₄@rGO MNCs have shown magneto-antibacterial activity against gram-negative bacteria (Escherichia coli), whose efficacy depends on the value of the rGO content. In contrast, the CoFe₂O₄@rGO MNC (25 wt% rGO) which was synthesized by the one-step hydrothermal method not only has a narrow band gap energy (for photocatalytic applications), but also significant magneto-antibacterial activity was observed.

Innovative Options for Bone Metastasis Treatment: An Extensive Analysis on Biomaterials-Based Strategies for Orthopedic Surgeons

Bone is the third most frequent site of metastasis, with a particular incidence in breast and prostate cancer patients. For example, almost 70% of breast cancer patients develop several bone metastases in the late stage of the disease. Bone metastases are a challenge for clinicians and a burden for patients because they frequently cause pain and can lead to fractures. Unfortunately, current therapeutic options are in most cases only palliative and, although not curative, surgery remains the gold standard for bone metastasis treatment. Surgical intervention mostly provides the replacement of the affected bone with a bioimplant, which can be made by materials of different origins and designed through several techniques that have evolved throughout the years simultaneously with clinical needs. Several scientists and clinicians have worked to develop biomaterials with potentially successful biological and mechanical features, however, only a few of them have actually reached the scope. In this review, we extensively analyze currently available biomaterials-based strategies focusing on the newest and most innovative ideas while aiming to highlight what should be considered both a reliable choice for orthopedic surgeons and a future definitive and curative option for bone metastasis and cancer patients.

Dental Adhesive Interfaces Reinforced with Magnetic Nanoparticles: Evaluation and Modeling with Micro-CT versus Optical Microscopy

Dental adhesives are used in a wide range of applications, including to place direct composite restorations in frontal or posterior teeth. One of the most frequent causes for the failure of composite resin restorations is microleakages. The first aim of this work is to introduce a new type of self-etched dental adhesive doped with magnetic nanoparticles (MPs) synthetized in the laboratory. The scope is to produce adhesives with a minimized width/thickness to decrease the risk of microleakages. The second aim is to assess the width/thickness of the adhesive layer in all the characteristic areas of the teeth using both the less precise but most common optical microscopy and the more accurate and volumetric micro-Computed Tomography (CT) investigations. Twenty extracted teeth have been divided into four groups: Group 1 includes 'blank' samples with adhesives that are not doped with MPs; Group 2 includes samples with adhesives doped with MPs; Groups 3 and 4 include samples with adhesives doped with MPs that are subjected to an active magnetic field for 5 and 10 min, respectively. Microscopy investigations followed by micro-CT and EDAX are performed on the adhesive. While a rather good agreement is obtained between the microscopy and micro-CT results, the capability of the latter to offer a full volumetric reconstruction of the layer is exploited to analyze the adhesion of the four considered dental materials. Thus, from micro-CT results the graphs of the surface areas as functions of the adhesive layer width are modeled mathematically, as well as the volume of sealants, for each of the four groups. To our knowledge, it is the first time that such a methodology is used. Characteristic parameters are extracted and the ascertainment of the optimal parameter that should be utilized for such assessments is discussed. The study demonstrates the adhesion improvement produced for Groups 3 and 4, where MPs are used. It also concludes that the magnetic field should be applied to the adhesive material for the longest possible exposure time (with a trade-off with the clinical duration of the treatment).

Mg(1-x)CuxFe2O4 superparamagnetic nanoparticles as nano-radiosensitizer agents in radiotherapy of MCF-7 human breast cancer cells

Magnesium-doped copper spinel ferrite superparamagnetic nanoparticles (Mg_(1-x)Cu_xFe₂O₄ SPMNPs, 0.2 ≤ x ≤ 0.8) were successfully synthesized by a hydrothermal method. The cytotoxicity effects and cell viability of MCF-7 on human breast cancer cells pre and post exposure to the Mg_1-xCu_xFe₂O₄ SPMNPs at different concentrations of 0.1, 1, 10 and 100 μg ml^-1 under radiotherapy were studied by MTT (3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay. Here, x-ray diffraction, scanning electron microscopy, atomic force microscopy, UV-visible spectrophotometry, Fourier transform infrared spectroscopy and vibrating-sample magnetometry were evaluated for the crystal structure, morphology, optical and magnetic property of the Mg_(1-x)Cu_xFe₂O₄ SPMNPs. The results showed that the Mg_(1-x)Cu_xFe₂O₄ SPMNPs all at x values had no significant cytotoxicity at concentrations of 0.1,1 and 10 μg ml^-1, but were enhanced by increasing of Cu content. Furthermore, cell destruction of MCF-7 human breast cancer cells post exposure to Mg_(1-x)Cu_xFe₂O₄ SPMNPs under x-ray irradiation was enhanced by increasing the Cu content and concentration. Superparamagnetic properties of the Mg_(1-x)Cu_xFe₂O₄ SPMNPs cause their localization and elimination, by only an external magnetic field. In conclusion, the Mg_(1-x)Cu_xFe₂O₄ SPMNPs with optimum values of x = 0.2 (10 μg ml^-1) and x = 0.6 (1 μg ml^-1) can be considered as a nano-radiosensitizer because of the synergistic treatment effect without cytotoxicity on the MCF-7 cells.

Bioinspired Polymeric-based Core-shell Smart Nano-systems

Smart nanosystems (SNs) have the potential to revolutionize drug delivery. Conventional drug delivery systems have poor drug-loading, early burst release, limited therapeutic effects, etc. Thus, to overcome these problems, researchers have taken advantage of the host-guest interactions as bioinspired nanosystems which can deliver nanocarriers more efficiently with the maximum drug loading capacity and improved therapeutic efficacy as well as bioavailability. SNs employ nanomaterials to form cage molecules by entrapping new nanocarriers called smart nanosystems in their cargo and design. The activities of SNs are based on responsive materials that interact with the stimuli either by changing their properties or conformational structures. The aptitude of living systems to respond to stimuli and process information has encouraged researchers to build up integrated nanosystems exhibiting similar function and therapeutic response. Various smart materials, including polymers, have been exhaustively employed in fabricating different stimuli-responsive nanosystems which can deliver bioactive molecules to a specific site for a certain period with minimal side effects. SNs have been widely explored to deliver diverse kinds of therapeutic agents ranging from bioactive compounds, genes, and biopharmaceuticals like proteins and peptides, to diagnostic imaging agents for biomedical applications. Nanotechnology-based different nanosystems are promising for health care issues. The advancement of SNs with physical science and engineering technology in synthesizing nanostructures and their physicochemical characterization should be exploited in medicine and healthcare for reducing mortality rate, morbidity, disease prevalence and general societal burden.

Synergism of wt-p53 and synthetic material in local nano-TAE gene therapy of hepatoma: comparison of four systems and the possible mechanism

Background

TAE-gene therapy for hepatoma, incorporating the tumor-targeted therapeutic efficacy of trans-arterial embolization, hydroxyapatite nanoparticles (nHAP) and anti-cancer wild-type p53 gene (wt-p53), was presented in our former studies (Int J Nanomedicine 8:3757-68, 2013, Liver Int 32:998-1007, 2012). However, the incompletely antitumoral effect entails defined guidelines on searching properer materials for this novel therapy.

Methods

Unmodified nHAP, Ca⁽²⁺⁾ modified nHAP, poly-lysine modified nHAP and liposome were separately used to form U-nanoplex, Ca-nanoplex, Pll-nanoplex, L-nanoplex respectively with wt-p53 expressing plasmid. The four nanoplexs were then applied in vitro for human normal hepacyte L02 and hepatoma HePG2 cell line, and in vivo for rabbits with hepatic VX2 tumor by injection of nanoplexs/lipiodol emulsion into the hepatic artery in a tumor target manner. The distribution, superficial potential, physical structure, morphology and chemical compositions of nanoplexs were evaluated by TEM, SEM, EDS etc., with the objective of understanding their roles in hepatoma TAE-gene therapy.

Results

In vitro, L-nanoplex managed the highest gene transferring efficiency. Though with the second highest transfection activity, Pll-nanoplex showed the strongest tumor inhibition activity while maintaining safe to the normal hepacyte L02. In fact, only Pll-nanoplex can combine both the antitumoral effect to HePG2 and safe procedure to L02 among the four systems above. In vivo, being the only one with successful gene transference to hepatic VX2 tumor, Pll-nanoplex/lipiodol emulsion can target the tumor more specifically, which may explain its best therapeutic effect and hepatic biologic response. Further physical characterizations of the four nanoplexs suggested particle size and proper electronic organic surface may be crucial for nano-TAE gene therapy.

Conclusion

Pll-nanoplex is the most proper system for the combined therapy due to its selectively retention in liver cancer cells, secondary to its morphological and physico-chemical properties of nanometric particle size, steady emulsion, proper organic and electronic surface.

Size effect of nano-hydroxyapatite on proliferation of odontoblast-like MDPC-23 cells

Nano-hydroxyapatite (nano-HAP) is supposed to be a promising candidate for apatite substitute in hard tissue engineering. We aimed to investigate the effect of nano-HAP particles on the proliferation of odontoblast-like MDPC-23 cells compared with conventional hydroxyapatite (c-HAP). HAP in diameter of ~20 nm (np20), ~70 nm (np70) and ~200 nm (c-HAP) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). Inverted microscope and MTT assay were used to detect the morphology and proliferation rate of MDPC-23 cells; TEM was used to reveal the internalization of HAP. We found that nano-HAP (np20 and np70), especially np20 expressed obvious growth-promoting effect on MDPC-23 cells compared with c-HAP, which caused the most vacuole in MDPC-23 cells. These results suggest that nano-HAP may be an optimal choice of apatite substitute for MDPC-23 cells on the aspect of cell proliferation.

Fabrication, multi-scale characterization and in-vitro evaluation of porous hybrid bioactive glass polymer-coated scaffolds for bone tissue engineering

Bioactive glass-based scaffolds are commonly used in bone tissue engineering due to their biocompatibility, mechanical strength and adequate porous structure. However, their hydrophobicity and brittleness limits their practical application. In this study, to improve nanomechanical properties of such scaffolds, pure bioactive hybrid glass and two bioactive hybrid glass-polymer coated composites were fabricated. A complementary micro and nanoscale characterization techniques (SEM, AFM, μCT, FTIR, compressive test, goniometer) were implemented for detailed description of architecture and physicochemical properties of hybrid bioactive glass-based scaffolds with emphasis on nano-mechanics. The final step was in-vitro evaluation of three dimensional macroporous structures. Our findings show that after polymer addition, architecture, topography and surface properties of the scaffolds were changed and promoted favoured behaviour of the cells.

Selected developments and medical applications of organic-inorganic hybrid biomaterials based on functionalized spherosilicates

Well-defined and tailor-made spherosilicates and POSS-based (POSS = Polyhedral Oligomeric Silsesquioxanes) (nano)composites with interesting chemical and mechanical properties have applications in the widely-regarded field of innovative biomaterials. They can serve as delivery systems, three-dimensional scaffolds for specific tissue engineering, biomaterials for orthopedic, cardiovascular, and reconstructive surgery, etc. Such organic-inorganic hybrids are much more effective biomaterials than pure polymers, bioglasses, metals, alloys, and ceramics currently used in medical applications and are considered as next-generation systems in innovative medical approaches. This range of applications creates a strong impetus for novel, cheap, and easy-to-scale-up methods for their synthesis. In this review (highlights since 2006), selected biomaterials consisting of various polymeric derivatives such as polymethacrylates, polylactides, polycaprolactones, polyurethanes, etc., which serve as organic side-arms of POSS and can create polymer platforms for precisely localized spherosilicates among organic matrices, are discussed as a new generation of silicon-based biosystems using spherosilicates, promising biomaterials with a particular use in soft- and hard-tissue engineering.

Synthesis of cubic spherosilicates for self-assembled organic–inorganic biohybrids based on functionalized methacrylates

Covalent hybrid networks created by fully substituted cubic spherosilicates containing functionalized methacrylates as side chains were synthesized.