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Bioactive phosphate glasses incorporated with Zn2+ (predicted to be useful for bone regeneration applications) were synthesized. Characterization of the bioglasses were done using XRD, FTIR, SEM, and EDS techniques, both prior to and after soaking in simulated body fluid (SBF) solution. The bioactive performance of samples was evaluated by incubated in SBF for different days by means of the pH measuring and comparing the results of XRD and SEM studies. The obtained results show the formation of hydroxyapatite (HAP) layer on the surface of as-developed bioactive glasses. The degradation of the samples evaluated by weight loss and pH of the remnant solution measured as functions of ZnO concentration and immersion time revealed the enhanced formation of HAP layer on the sample surface. The results further indicated the rate of degradation can be monitored by tailoring the concentration of ZnO and immersion time. The studies were also extended to in vitro cytocompatibility and cell proliferation measurements on rMSC using CCK-8 for incubation periods of 24 h and 72 h. These studies have revealed the considerable levels of rMSC proliferation and improved viability within the limits of nontoxic levels. The measurements of antibacterial activity of ZnO-doped phosphate bioactive glasses against E. coli and S. aureus, carried out for 24 h and 48 h have confirmed their potential antibacterial activity. Finally, quantitative analysis of these results confirmed an enhanced in vitro biological and antibacterial activity of the samples due to the ZnO doping and subsequent controlled release of Zn2+ ions in the glass matrix.

Calcium oxalate monohydrate (COM) crystal is the most common crystalline component of human kidney stones. The molecular-scale inhibitory mechanisms of COM crystal growth by urinary biomolecules such as citrate and osteopontin adsorbed onto the crystal surface are now well understood. However, the pathways by which dissolved calcium and oxalate ions are incorporated into the molecular step of the COM crystal surface, leading to COM crystal growth-a prerequisite to be elucidated for developing effective therapeutics to inhibit COM stones-remain unknown. Here, using in situ liquid-phase atomic microscopy along with a step kinetic model, we reveal the pathways of the calcium and oxalate ions into the COM molecular step via the growth speed analysis of the molecular steps with respect to their step width at the nanoscale. Our results show that, primarily, the ions are adsorbed onto the terrace of the crystal surface from the solution-the rate-controlling stage for the molecular step growth, i.e., COM crystal growth-and then diffuse over it and are eventually incorporated into the steps. This primary pathway of the ions is unaffected by the model peptide D-Asp6 adsorbed on the COM crystal surface, suggesting that urinary biomolecules will not alter the pathway. These new findings rendering an essential understanding of the fundamental growth mechanism of COM crystal at the nanoscale provide crucial insights beneficial to the development of effective therapeutics for COM kidney stones.

Bioactive and biodegradable fibrous membranes are highly attractive for periodontal bone regeneration. Herein, we demonstrate a new approach for fabrication of a novel nano/micro-structured fibrous membrane made of biodegradable poly(ϵ-caprolactone)/gelatin (PCL/GEL) nanofibers and biomemtically-grown hydroxyapatite spherules (HAs). The proposed approach includes electrospinning fabrication of PCL/GEL nanofibers containing nanobioglass (NBG) agglomerates and their biomimetic transformation into HAs. The NBG agglomerates (~1.9 μm in diameter) enabled the growth of biomimetic HAs (~4 μm in diameter) around the PCL/GEL nanofibers and generated a unique nano/micro-structure. Interestingly, the biomimetically-grown HAs imparted the PCL/GEL-HAs nanofibrous membrane with several remarkable properties including nano/micro-topography, bone-mimetic composition (Ca/P = 1.60), large specific surface area (~31 m2/g), high protein adsorption capacity (~157 μg protein/mg membrane) and controlled protein delivery with zero-order release kinetics; along with sustained release of therapeutic ions (Ca2+ ~ 37 ppm, PO43− ~ 24 ppm, and SiO44− ~ 61 ppm). Furthermore, the PCL/GEL-HAs membrane exhibited enhanced wettability, good biodegradability and adequate mechanical properties. Collectively, the PCL/GEL-HAs demonstrated unique properties and it can be considered as a novel multifunctional bioactive/biodegradable membrane for periodontal bone regeneration.

Nanomaterials combined with phototherapy and multimodal imaging are promising for cancer theranostics. Our aim is to develop fluorescent mesoporous bioglass nanoparticles (fBGn) based on carbon dots (CD) with delivery, triple-mode imaging, and photothermal (PTT) properties for cancer theranostics. A direct and label-free approach was used to prepare multicolor fluorescent fBGn with 3-aminopropyl triethoxysilane as the surface-functionalizing agent. The calcination at 400 °C provided fBGn with high fluorescence intensity originating from the CD. In particular, a triple-mode emission [fluorescence imaging, two-photon (TP), and Raman imaging] was observed which depended on CD nature and surface properties such as surface oxidation edge state, amorphous region, nitrogen passivation of surface state, and crystalline region. The fBGn also exhibited phototherapeutic properties such as photodynamic (PDT) and PTT effects. The antitumor effect of the combined PDT/PTT therapy was significantly higher than that of individual (PDT or PTT) therapy. The fBGn, due to the mesoporous structure, the anticancer drug doxorubicin could be loaded and released in a pH-dependent way to show chemotherapy effects on cancer cells. The in vivo imaging and biocompatibility of fBGn were also demonstrated in a nude mouse model. The fBGn, with the combined capacity of anticancer delivery, triple-mode imaging, and PTT/PDT therapy, are considered to be potentially useful for cancer theranostics.

Providing appropriate biophysical and biochemical cues to the interface is a facile strategy to enhance the osteogenic ability of metallic implants. Here we exploited this through the incorporation of mesoporous bioactive glass nanoparticles (MBGN) at a high content (1:1 by weight) to a biopolymer chitosan in the electrodeposition process of titanium. The MGBN/chitosan layer thickness, tunable by electrodeposition parameters, exhibited an accelerated ability of apatite mineral induction in a body simulating medium. Of note, the involvement of MBGN could generate nanoscale roughness in a unique range of 10-25 nm. Moreover, the layer showed a slowly releasing profile of ions (calcium and silicate) over weeks at therapeutically relevant doses. The ion-releasing nanotopological surface was demonstrated to alter the preosteoblasts responses in a way favorable for osteogenic differentiation. The combinatory cues of nanotopology (25 nm roughness) and ion release enabled highly accelerated cellular anchorage with somewhat limited spreading area at initial periods. The subsequent osteoblastic differentiation behaviors on the engineered surface, as examined up to 21 days, showed significantly enhanced alkaline phosphate activity and up-regulated expression of bone-associated genes (ALP, Col I, OPN, and OCN). These results indicate that the combinatory cues provided by nanotopology (25 nm roughness) and ions released from MBGN are highly effective in stimulating osteoblastic differentiation and suggest that the MBGN/chitosan may serve as a potential composition for bone implant coatings.

A novel glass system 8ZnO–22Na2O–(24-x)CaO–46P2O5–xTiO2 (x = 0.2, 0.4, 0.6, 0.8 and 1 mol%) was fabricated and investigated in detail for the appropriateness in the use of bone repair and regeneration applications. In this context, we explored the structural, thermal, mechanical, degradation, pH evaluation along with antibacterial assay, cytocompatability and cell proliferation by various characterization techniques like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive spectrometry (EDS) and differential thermal analysis (DTA), Vickers hardness, cell counting kit (CCK8) method and agar plates method. The obtained results of density, thermal stability and Vickers hardness increase with the increasing content of TiO2 leads to the densification of glass structure dueto formation new linkages P–O–Ti and enters into the network in the form of either TiO4 or TiO5/6 structural units. The formation of a rich crystalline hydroxyl apatite (HAp) layer on the samples with incubation time (3, 7, 14 and 21days) and content of TiO2 up to 0.6 mol% in simulated body fluid (SBF) were confirmed by in vitro analysis. Interestingly, no inhibitory effects on HAp layer formation with the addition of titanium up to 1 mol% were noticed. Lower degradation rate and pH values endorsed to hydration resistant with Ti4+ inclusion, leads to controlled ion leaching. The rat mesenchymal stem cells (rMSCs) growth on glass samples showed the enhanced biocompatibility and proliferation without toxicity. In addition, all glasses possess good antimicrobial properties against bacterial species Escherichia coli (E.coli). Finally, the results revealed that the 0.6 mol% of TiO2 glass (T.6) showed abundant performance for bone generation applications.

Objective Odontoblast differentiation from dental pulp stem cells (DPSCs) is involved in a cascade of key biological events for maintaining pulp-dentin homeostasis, repair and regeneration. A pulp regeneration biomaterial (mineral trioxide aggregate (MTA)) increased intracellular reactive oxygen species (ROS) levels during differentiation, ameliorating the differentiating of DPSCs into odontoblasts. Here, ceria nanoparticles (CNP) were incorporated as an insoluble antioxidant into commercially available MTA (CMTA), and the odontoblastic differentiation of human DPSCs was investigated. Methods The CMTA was fabricated from MTA and CNP conjugation up to 4 wt%, and the compressive strength, surface morphology after setting and setting time were investigated. Furthermore, the alkaline phosphatase (ALP) assay, Alizarin Red staining (ARS) and quantitative real-time polymerase chain reaction (qPCR) were performed to evaluate odontoblastic differentiation in an indirect co-culture system using inserts with pores. To reveal the underlying mechanism, the ROS levels and ion release were measured. Statistical analysis was performed by one-way analysis of variance with a Tukey post hoc test (P Results CMTA significantly elevated the odontoblastic differentiation of hDPSCs measured by ALP activity, ARS, and odontoblastic gene expression, whereas the other physico-mechanical properties were relatively maintained. Upregulation of gene expression from CMTA was reversed with hydrogen peroxide. CMTA could reduce the increased intracellular ROS levels of hDPSCs by approximately 70% during differentiation, similar to when an antioxidant was used, without changing the ion release and pH of the media. Significance CMTA could be useful dental materials for regenerating dentin-pulp complexes by instructing intracellular ROS during differentiation to achieve beneficial biological functions. This study suggests a new direction of dental nanomaterials in treating pulp-dentin complexes.

Glial cell alignment in tissue engineered constructs is essential for achieving functional outcomes in neural recovery. While gelatin methacrylate (GelMA) hydrogel offers superior biocompatibility along with permissive structure and tailorable mechanical properties, phosphate glass fibers (PGFs) can provide physical cues for directionality of neural growth. Aligned PGFs were fabricated by a melt quenching and fiber drawing method and utilized with synthesized GelMA hydrogel. The mechanical properties of GelMA and biocompatibility of the GelMA-PGFs composite were investigated in vitro using rat glial cells. GelMA with 86% methacrylation degree were photo-crosslinked using 0.1%wt photo-initiator (PI). Photocrosslinking under UV exposure for 60 s was used to produce hydrogels (GelMA-60). PGFs were introduced into the GelMA before crosslinking. Storage modulus and loss modulus of GelMA-60 was 24.73 ± 2.52 and 1.08 ± 0.23 kN/m2 , respectively. Increased cell alignment was observed in GelMA-PGFs compared with GelMA hydrogel alone. These findings suggest GelMA-PGFs can provide glial cells with physical cues necessary to achieve cell alignment. This approach could further be used to achieve glial cell alignment in bioengineered constructs designed to bridge damaged nerve tissue.

Although emergence of bone tissue engineering techniques has revolutionized the field of maxillofacial reconstruction, the successful translation of such products, especially concerning larger sized defects, still remains a significant challenge. Light-curable methacrylate-based polymers have ideal properties for bone repair. These materials are also suitable for 3D printing which can be applicable for restoration of both function and aesthetics. The main objective of this research was to synthesize a mechanically stable and biologically functional polymer for reconstruction of complex craniofacial defects. The experimental work initially involved synthesis of (((3R,3aR,6S,6aR)-hexahydrofuro[3,2-b]furan-3,6-diyl)bis(oxy))bis(ethane-2,1-diyl)bis((4-methyl-3-oxopent-4-en-1-yl)carbamate), CSMA-1, and ((((((((((((3R,3aR,6S,6aR)-hexahydrofuro[3,2-b]furan-3,6-diyl)bis(oxy))bis(ethane-2,1 diyl))bis(oxy))bis(carbonyl))bis(azanediyl))bis(methylene))bis(3,3,5-trimethylcyclohexane-5,1-diyl))bis(azanediyl))bis(carbonyl))bis(oxy))bis(ethane-2,1-diyl)bis(2-methylacrylate), CSMA-2; nuclear magnetic resonance analysis confirmed formation of the monomers, and composite samples were fabricated respectively by exposing 11 mm diameter discs to blue light. Modulus of elasticity was determined using a biaxial flexural test and the values were found to be between 1 and 3 GPa in CSMA-1, CSMA-2, and their composites. In vitro cell culture, using human bone marrow-derived mesenchymal stem cells, confirmed nontoxicity of the samples and finally 3D printing allowed direct photo-polymerization and setting of the bio ink into a 3D construct.

Electrospinning is a well-known technique for the production of fibers from a range of hundreds of micrometers to a 10th of nanometers. This technique is simple, versatile, cost-effective, high production rate, and very relevant in industry and biomedical research. In this chapter, we have highlighted the basics of electrospinning with apparatus setups, solution parameters (viscosity, surface tension, and solvent), electrospun parameters (applied voltage, tip-collector distance, flow rate, humidity, temperature, and needle gauge), choice of materials (polymer, composite, and ceramics), various types of fibers morphologies, and their physical characterization. The selection of materials and electrospinning parameters is the key and plays an important role in the production of specific morphologies (nonwoven fiber, ribbon, wavy, alignment, random, porous, and bead) of the fibers with unique characteristics such as porosity, permeability, high surface-to-volume ratio, and high mechanical strength. This chapter provides a comprehensive outlook on the preparation and characterization of the electrospinning nanofibers and insights about the about technique in biomedical applications.

Using microspherical scaffolds as building blocks to repair bone defects of specific size and shape has been proposed as a tissue engineering strategy. Here, phosphate glass (PG) microcarriers doped with 5 mol % TiO2 and either 0 mol % CoO (CoO 0%) or 2 mol % CoO (CoO 2%) were investigated for their ability to support osteogenic and vascular responses of human mesenchymal stem cells (hMSCs). Together with standard culture techniques, cell-material interactions were studied using a novel perfusion microfluidic bioreactor that enabled cell culture on microspheres, along with automated processing and screening of culture variables. While titanium doping was found to support hMSCs expansion and differentiation, as well as endothelial cell-derived vessel formation, additional doping with cobalt did not improve the functionality of the microspheres. Furthermore, the microfluidic bioreactor enabled screening of culture parameters for cell culture on microspheres that could be potentially translated to a scaled-up system for tissue-engineered bone manufacturing.

Three-dimensional (3D) printing enhances the production of on-demand fabrication of patient-specific devices as well as anatomically fitting implants with high complexity in a cost-effective manner. Additive systems that employ vat photopolymerisation such as stereolithography (SLA) and digital light projection (DLP) are used widely in the field of biomedical science and engineering. However, additive manufacturing methods can be limited by the types of materials that can be used. In this study, we present an isosorbide-based formulation for a polymer resin yielding a range of elastic moduli between 1.73 GN/mm2 dependent on the photoinitiator system used as well as the amount of calcium phosphate filler added. The monomer was prepared and enhanced for 3D-printing using an SLA technique that delivered stable and optimized 3D-printed models. The resin discussed could potentially be used following major surgery for the correction of congenital defects, the removal of oral tumours and the reconstruction of the head and neck region. The surgeon is usually limited with devices available to restore both function and appearance and with the ever-increasing demand for low-priced and efficient facial implants, there is an urgent need to advance new manufacturing approaches and implants with a higher osseointegration performance.

Carbon-based nanomaterials include fullerenes, carbon nanotubes, graphene and its derivatives, graphene oxide, nanodiamonds, and carbon-based quantum dots. Due to their unique structural dimensions and excellent mechanical, electrical, thermal, optical and chemical properties, these materials have attracted significant interest in diverse areas, including biomedical applications. Among them, there has been recent focus on the imaging of cells and tissues and the delivery of therapeutic molecules for disease treatment and tissue repair. The broad-range one-photon property of carbon based-nanomaterials together with their biocompatibility and ease of functionalization has made them candidate imaging agents for tumor diagnosis. In particular, the intrinsic two-photon fluorescence property of carbon based-nanomaterials in the long wavelength region (near-infrared II) allows deep-tissue optical imaging. This review highlights the recent development on carbon based-nanomaterials in the field of one-photon and two-photon imaging and discusses their possible and promising diagnostic and therapeutic applications for the treatment of various diseases including cancer.

Bioactive nanostructured coating has been a key strategy to improve the cell adhesion and osseointegration of metallic implants. This study presents the electrophoretic coatings of hydroxyapatite with tunable nanocrystal morphologies. The hydroxyapatite nanocrystals were prepared with three different elongated dimensions by the hydrothermal method (∼80 nm; SHA, ∼300 nm; MHA, and ∼900 nm; LHA), which were used in combination with a fugitive biopolymer chitosan for the electrophoretic deposition on titanium. All the HA coatings were densely and homogeneously deposited and had different and unique nanotopologies and corresponding surface areas. The coating parameter significantly altered the cell behaviors including anchorage, spreading and proliferation; the cell adhesion was better on the small- and middle-sized nanocrystals (SHA, MHA > LHA), which was interestingly opposite in cell spreading (LHA > SHA, MHA), and then the cell proliferation was again up-regulated on SHA and MHA. Although more studies are needed to elucidate the biological phenomenon, the sets of results imply the importance of tailored nanocrystal morphology in the initial (adhesion and growth) cellular events.

Injectable calcium phosphate cements (CPCs) with strong mechanical properties and improved biological performance have the potential to be extensively used for bone regeneration. Although many additive materials have been incorporated into CPCs in order to achieve improvements in their mechanical and biological properties, somehow the results have not been fully satisfactory. Here we focus on using the nanoparticle form of mesoporous bioactive glasses (mBGn) as additive nano-components for alpha-tricalcium phosphate-based CPCs. The effects of mBGn incorporated up to 10 wt% into CPCs were examined in depth with respect to the setting time, morphology, injectability, wash-out properties, consistency, ionic release, pH change, and mechanical strength. The addition of mBGn significantly increased the surface area (for both the as-cemented and the hydrated compositions) and also significantly accelerated the setting reaction of CPCs. The injectability and the anti-washout property of CPCs were remarkably enhanced with the addition of mBGn. In striking contrast to the case of pure CPCs, the morphological changes observed in simulated body fluid (SBF) revealed a spherical development of apatite crystals, replicating the nanospherical morphology of the mBGn and consequently resulting in a nano-micro-roughened surface. The mechanical compressive strength substantially increased after SBF immersion and significantly higher values were recorded for mBGn/CPC as compared to pure CPCs. The ion release, including that of calcium, phosphate, and silicon, was recorded at substantial levels during the test period, and the addition of mBGn caused changes in the pH towards less acidic. The in vivo study of the mBGn/CPCs in rat subcutaneous tissue confirmed excellent tissue compatibility with little evidence of inflammatory reactions while exhibiting viable fibroblastic cells with a substantial presence of mature endothelial cells surrounding the cements. When implanted in a rat calvarium defect, a substantial degradation of the samples was noticed in the interfacial region. The proposed mBGn/CPC is a novel, promising cement formulation for the repair and regeneration of bone due to setting characteristics, physico-chemical and mechanical properties, and excellent in vivo tissue compatibility and bioactivity.

Biocompatible and multifunctional nanocarriers significantly improve the therapeutic and diagnostic efficacy of the cargo molecules. Here we report a novel biocompatible apatite nanocrystal-based delivery system with in situ imaging capacity. A nanorod (40 nm × 10 nm) produced by a citrate-involved sol–gel process expressed a strong blue emission at 427 nm under fluorescence microscopy. The CO2˙− radical impurities present in the apatite crystal lattice account for the fluorescent behavior. The fluorescent nanorods exhibited excellent cell viability (over 90% up to ∼100 μg ml−1 concentration for both osteoblasts and osteoclasts). The nanorods loaded alendronate drug at a high efficiency (10%) and released over 3 days, while enabling in situ fluorescence imaging within the cells. The fluorescent apatite was further hybridized onto the surface of mesoporous nanospheres, aimed at improving the drug-delivery capacity. Small interfering RNA (siRNA) gene, encoding Plekho-1, was effectively loaded to the hybrid nanocarrier, and was sustainably released over 5 days. The siRNA-loaded nanocarrier exhibited excellent osteoblastic uptake (96% efficiency) and gene-silencing effect, suppressing Plekho-1 down to ∼18%, while preserving intracellular fluorescence signals. Taken as a whole, the self-fluorescent nature of apatite nanorods is believed to find potential and versatile applications as biocompatible drug-delivery and in situ imaging systems.

Objective Titanium and its alloys are widely used for dental and medical biomaterials due to their excellent mechanical and biological advantages. After the introduction of direct laser metal sintering (DLMS) 3D printing technology and its use over conventional machine-cut processes, questions remain regarding whether 3D-printed titanium (alloy) devices have similar biological properties to machine-cut counterparts for dental applications. Thus, this work focuses on comparing the biological activities of machine-cut and 3D-printed specimens after optimizing the DLMS 3D-printing conditions in terms of the mechanophysical characteristics. Methods The DLMS 3D-printing (as a function of the laser spacing from 30–100 μm) and post-surface treatment (as-given or sand-blasted) conditions were optimized using medical-grade Ti-6Al-4V powders in terms of the inner pore amount, mechanical properties, roughness and hydrophilicity. Then, the initial cell adhesion of the optimized DLMS 3D-printed Ti-6Al-4V specimen was compared with that of the machine-cut Ti-6Al-4V specimen against human dermal fibroblasts (hDFs) and mesenchymal stem cells (hMSCs), which are representative of direct-contact cell types of orofacial mucosa and bone, respectively. hMSC differentiation on the specimens was conducted for up to 21 days to measure the osteogenic gene expression and biomineralization. Results Laser spacings of 30–40 μm had fewer inner defects and consequently a higher three-point flexural strength and elastic modulus compared to other larger laser spacings. Depending on the span width (0.3–1 mm) in the lattice architecture, the elastic modulus of the 3D-printed cuboid specimen can be further controlled (up to ∼30 times). The sand-blasted specimens after 3D printing revealed lower surface roughness and higher hydrophilicity compared to the as-3D printed specimen, which were considered optimal conditions for biological study. Initial hDF and hMSC adhesion for 12 hr and hMSC differentiation on the surface were comparable between the sand-blasted 3D-printed and machine-cut specimens in terms of adherent cell numbers, vinculin intensity, osteogenic gene expression and biomineralization. Significance The optimized DLMS 3D-printed Ti-6Al-4V specimen had similar biological properties to those of the machine-cut counterpart, suggesting the potential usefulness of 3D printing technology for a wide range of dental applications.

A bone-filler is expected to accomplish diverse purposes such as osteoblastogenesis, osteoclastogenesis and anti-bacterial activity. Taken into consideration of the potent antibacterial activity of certain trace elements, in present study, the effect of Zn-doping in tricalcium silicate cement is explored by means of its biological function. Cement setting reaction is slowed down with Zn addition, while the compressive strength of the doped cement increases. In stimulating body fluid, Zn is incorporated slowly into developing apatite nuclei; it results in restricted apatite crystallization and formation of amorphous apatite layer. The slow release of zinc ions into culture medium, greatly enhances the proliferation and alkaline phosphatase activity of rat bone marrow stromal cells. Released Zn2+ also takes part in bone-remodeling; facilitates osteoclastogenesis in RAW 264.7 (in presence of RANKL). Furthermore, the accumulation of Zn2+ at bacterial membrane impairs membrane permeability, causing death of both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterias. The data indicate a gradual release of Zn ions from the bioactive injectable doped calcium silicate; these ions modulate bone metabolism induce concentration-dependent cell proliferation, render osteo-inductivity to self-curing cement. Zn also imparts anti-bacterial property to C3S; perquisite for medical bone implants.

Objective Although polymethyl methacrylate (PMMA) is widely used as a dental material, a major challenge of using this substance is its poor antimicrobial (anti-adhesion) effects, which increase oral infections. Here, graphene-oxide nanosheets (nGO) were incorporated into PMMA to introduce sustained antimicrobial-adhesive effects by increasing the hydrophilicity of PMMA. Methods After characterizing nGO and nGO-incorporated PMMA (up to 2 wt%) in terms of morphology and surface characteristics, 3-point flexural strength and hardness were evaluated. The anti-adhesive effects were determined for 4 different microbial species with experimental specimens and the underlying anti-adhesive mechanism was investigated by a non-thermal oxygen plasma treatment. Sustained antimicrobial-adhesive effects were characterized with incubation in artificial saliva for up to 28 days. Results The typical nanosheet morphology was observed for nGO. Incorporating nGO into PMMA roughened its surface and increased its hydrophilicity without compromising flexural strength or surface hardness. An anti-adhesive effect after 1 h of exposure to microbial species in artificial saliva was observed in nGO-incorporated specimens, which accelerated with increasing levels of nGO without significant cytotoxicity to oral keratinocytes. Plasma treatment of native PMMA demonstrated that the antimicrobial-adhesive effects of nGO incorporation were at least partially due to increased hydrophilicity, not changes in the surface roughness. A sustained antimicrobial-adhesive property against Candida albicans was observed in 2% nGO for up to 28 days. Significance The presence of sustained anti-adhesion properties in nGO-incorporated PMMA without loading any antimicrobial drugs suggests the potential usefulness of this compound as a promising antimicrobial dental material for dentures, orthodontic devices and provisional restorative materials.

Healing and repair of damaged bones with various geometries are challenging issues in personalized regenerative medicine. Herein, we examine if the engineered electroblown scaffolds can be suitable to this purpose with the ability to shape and fill defects, populate stem cells, and stimulate the regeneration process of defected bone. The electroblowing method could generate bioactive nanocomposite scaffolds made of poly(caprolactone) and bioactive glass nanoparticles, of which the macrostructure is highly spaced and fibrous networked. The scaffolds were easily formable to different shapes with space filling ability, and were hydrophilic to soak water and blood rapidly. Multipotent stem cells from dental pulp effectively infiltrated the scaffold networks, anchored the fiber surface within few hours, proliferated actively over weeks, and were stimulated to differentiate into osteogenic cells. The cell/scaffold constructs, implanted to tooth-extracted, irregular-shaped alveolar bone defects, were shown to fit the defect and to stimulate early new bone formation. Taken together, the electroblown bioactive fibrous scaffolds and their constructs with multipotent dental stem cells may be useful as a potential 3D platform for future personalized bone tissue engineering.

This study investigated the mechanical and in vitro biological properties (in immortalized human dental pulp stem cells (ihDPSCs)) of bioactive glass nanoparticle (BGN)-incorporated glass ionomer cement (GIC) with or without chitosan as a binder.After the BGNs were synthesized and characterized, three experimental GICs and a control (conventional GIC) that differed in the additive incorporated into a commercial GIC liquid (Hy-bond, Shofu, Japan) were produced: BG5 (5wt% of BGNs), CL0.5 (0.5wt% of chitosan), and BG5+CL0.5 (5wt% of BGNs and 0.5wt% of chitosan). After the net setting time was determined, weight change and bioactivity were analyzed in simulated body fluid (SBF) at 37°C. Mechanical properties (compressive strength, diametral tensile strength, flexural strength and modulus) were measured according to the incubation time (up to 28 days) in SBF. Cytotoxicity (1day) and biomineralization (14 days), assessed by alizarin red staining, were investigated using an extract from GIC and ihDPSCs. Data were analyzed using one-way analysis of variance (ANOVA) followed by Tukey's post hoc test; p0.05.BGNs were sol-gel synthesized to be approximately 42nm in diameter with a spherical morphology and amorphous structure. After the bioactivity and suspension ability of the BGNs were confirmed, all the experimental GIC groups had setting times of less than 6min and approximately 1% weight loss after 28days of incubation. In addition, BGNs incorporated into GIC (BG5 and BG5+CL0.5) exhibited surface bioactivity. The mechanical properties were increased in the BGN-incorporated GICs compared to those in the control (p0.05). Without cytotoxicity, the biomineralization capacity was ranked in the order BG5, BG5+CL0.5, control, and CL0.5 (p0.05).BGN-incorporated GIC showed enhanced mechanical properties such as compressive, diametral tensile and flexural strength as well as in vitro biomineralization properties in ihDPSCs without cytotoxicity. Therefore, the developed BGN-incorporated GIC is a promising restorative dental material, although further in vivo investigation is needed before clinical application.

Theranostics based on nanoparticles (NPs) is a promising paradigm in nanomedicine. Mesoporous silica nanoparticle (MSN)-based systems offer unique characteristics to enable multimodal imaging or simultaneous diagnosis and therapy. They include large surface area and volume, tunable pore size, functionalizable surface, and acceptable biological safety. Hybridization with other NPs and chemical modification can further potentiate the multifunctionality of MSN-based systems toward translation. Here, we update the recent progress on MSN-based systems for theranostic purposes. We discuss various synthetic approaches used to construct the theranostic platforms either via intrinsic chemistry or extrinsic combination. These include defect generation in the silica structure, encapsulation of diagnostic NPs within silica, their assembly on the silica surface, and direct conjugation of dye chemicals. Collectively, in vitro and in vivo results demonstrate that multimodal imaging capacities can be integrated with the therapeutic functions of these MSN systems for therapy. With further improvement in bioimaging sensitivity and targeting specificity, the multifunctional MSN-based theranostic systems will find many clinical applications in the near future.

Even though roughened titanium (Ti) and Ti alloys have been clinically used as dental implant, they encourage bacterial adhesion, leading to failure of the initial stability. Here, the non-thermal atmospheric pressure plasma jet (NTAPPJ) functionalized Ti and Ti alloy were investigated to promote cellular activities but inhibit the initial attachment of the adherent pioneer bacterium, Streptococcus sanguinis, without topographical changes.After the produced radicals from NTAPPJ were characterized, bacterial adhesion to specimens was assessed by PrestoBlue assay and live-dead staining with or without the NTAPPJ functionalizing. After the surface was characterized using optical profilometry, X-ray photoelectron spectroscopy and contact angle analysis, the ions released from the specimens were investigated. In vitro initial cell attachment (4h or 24h) with adhesion images and alkaline phosphatase activity (ALP, 14 days) measurements were performed using rat bone marrow-derived mesenchymal stem cells.The initial bacterial adhesion to the Ti and Ti alloy was significantly inhibited after NTAPPJ functionalizing (p0.05) compared to those without NTAPPJ functionalizing. The bacterial adhesion-resistance effect was induced by carbon cleaning, which was dependent on the working gas used on the Ti specimens (nitrogenammonia and air, p0.05). The initial cell adhesion with well-developed vinculin localization and consequent ALP activity at 14days to the NTAPPJ-functionalized specimens were superior to the non-treated specimens.For the promising success of dental implants, NTAPPJ functionalizing is suggested as a novel surface modification technique; this technique can help ensure the success of integration between the dental implants and bone tissues with less concern of inflammation.

Cerium oxide nanomaterials (CeNMs), due to their excellent scavenging properties of reactive oxygen species (ROS), have gained great promise for therapeutic applications. A high level of ROS often degrades the potential of stem cells in terms of survivability, maintenance and lineage differentiation. Here we hypothesize the CeNMs may play an important role in protecting the capacity of stem cells against the oxidative insult, and the suppression mechanism of ROS level may depend on the internalization of CeNMs. We synthesized CeNMs with different directional shapes (aspect ratios) by a pH-controlled hydrothermal method, and treated them to stem cells derived from human dental pulp at various doses. The short CeNMs (nanoparticles and nanorods) were internalized rapidly to cells whereas long CeNMs (nanowires) were slowly internalized, which led to different distributions of CeNMs and suppressed the ROS levels either intracellularly or extracellularly under the H 2 O 2 -exposed conditions. Resultantly, the stem cells, when dosed with the CeNMs, were rescued to have excellent cell survivability; the damages in intracellular components including DNA fragmentation, lipid rupture and protein degradation were significantly alleviated. The findings imply that the ROS-scavenging events of CeNMs need special consideration of aspect ratio-dependent cellular internalization, and also suggest the promising use of CeNMs to protect stem cells from the ROS-insult environments, which can ultimately improve the stem cell potential for tissue engineering and regenerative medicine uses. Statement of Significance Oxidative stress governs many stem cell functions like self-renewal and lineage differentiation, and the biological conditions involving tissue repair and disease cure where stem cell therapy is often needed. Here we demonstrate the unique role of cerium oxide nanomaterials (CeNMs) in rescuing stem cell survivability, migration ability, and intracellular components from oxidative stress. In particular, we deliver a novel finding that nano-morphologically varied CeNMs show different mechanisms in their scavenging reactive oxygen species either intracellularly or extracellularly, and this is related with their different cellular internalizations. We used human dental pulp stem cells for the model study and proved the CeNMs were effective in controlling ROS level by means of scavenging intracellularly or extracellularly, which ultimately led to improving the intact therapeutic potential of stem cells. This work touches an important biological issue of nanomaterial interactions with stem cells under the conditions related with oxidative stress and the resultant damage. The correlation of shape factor in therapeutic nanomaterials with stem cell interaction and the oxidative stress-related functions will provide informative ideas in the design of CeNMs for cellular therapy.

Angiogenic capacity of biomaterials is a key asset to drive vascular ingrowth during tissue repair and regeneration. Here we design a unique angiogenic microcarrier based on sol-gel derived mesoporous silica. The microspheres offer a potential angiogenic stimulator, Si ion, 'intrinsically' within the chemical structure. Furthermore, the highly mesoporous nature allows the loading and release of angiogenic growth factor 'extrinsically'. The Si ion is released from the microcarriers at therapeutic ranges (over a few ppm per day), which indeed up-regulates the expression of hypoxia inducing factor 1α (HIF1α) and stabilizes it by blocking HIF-prolyl hydroxylase 2 (PHD2) in HUVECs. This in turn activates the expression of a series of proangiogenic molecules, including bFGF, VEGF, and eNOS. VEGF is incorporated effectively within the mesopores of microcarriers and is then released continuously over a couple of weeks. The Si ion and VEGF released from the microcarriers synergistically stimulate endothelial cell functions, such as cell migration, chemotactic homing, and tubular networking. Furthermore, in vivo neo-blood vessel sprouting in chicken chorioallantoic membrane model is significantly promoted by the Si/VEGF releasing microcarriers. The current study demonstrates the synergized effects of Si ion and angiogenic growth factor through a biocompatible mesoporous microsphere delivery platform, and the concept provided here may open the door to a new co-delivery system of utilizing ions with growth factors for tissue repair and regeneration.

The proper choice of dental composite resins is necessary based on the minimal cytotoxicity and antiodontogenesis on human dental pulp stem cells for dental pulp-dentin tissue repair and regeneration. The aim of this study was to evaluate the cytotoxicity and antidifferentiation effects of dental bulk-fill resins, able to be polymerized as a bulk status for filling deep cavity of a tooth by single light curing, against human dental pulp stem cells (hDPSCs) from three compartments corresponding to depth (0-2, 2-4, and 4-6 mm) from the light-curing site. Three bulk-fill composite resins (SDR, Venus bulk-fill (VBF), and Beautifil Bulk Flowable (BBF)) and a conventional flowable composite resin (Filtek Z350 XT flowable restorative (ZFF)) were individually filled into a cylindrical hole (h=2 mm, Ф=10 mm), and three compartments (total ~6 mm of height) were combined as a single assembly for light curing. The resin samples from the three layers were separated and eluted in the culture medium. The extracts were exposed to hDPSCs, and cytotoxicity and differentiation capability were evaluated. Depth of cure and surface hardness according to depth were determined. All bulk-fill resins except BBF revealed cytotoxicity from 4 to 6 or 2 to 4 mm, while ZFF was cytotoxic at over 2 mm. Depth of cure was detected from 3.55 to 4.02 mm in the bulk-fill resins (vs. ~2.25 mm in conventional resin), and 80% hardness compared with that of a fully polymerized top surface was determined from 4.2 to 6 mm in the bulk-fill resin (vs. 2.4 mm in conventional resin). Antidifferentiation was revealed at a depth of 4-6 mm in the bulk-fill resin. There was a difference in depth of cytotoxicity and antidifferentiation between the bulk-fill composite resins, which was mainly due to different cure depths and ingredients. Therefore, careful consideration of choice of bulk-fill resins is necessary especially for restoration of deep cavities for maintaining the viability and differentiation ability of dental pulp stem cells.

Objective Although bisphenol A-glycidyl methacrylate (Bis-GMA)-based dental materials are widely used in dentistry, Estrogenicity from released bisphenol A remains a concern due to possibility of adversely affecting the growth of children and homeostasis of adults. Here, a new family of isosorbide-derived biomonomers were synthesized and experimentally utilized as a matrix of dental sealants to provide physico-mechanical and biological properties comparable to those of a conventional Bis-GMA-based material but without the the potential estrogenicity. Methods After synthesis of isosorbide-derived biomonomers (ISDB) by light polymerization, an experimental dental sealant with different silica filler concentrations (0–15 wt%) was characterized and compared to a commercially available Bis-GMA-based sealant. Cytotoxicity and estrogenicity assays were conducted with human oral keratinocytes and estrogen-sensitive MCF-7 cells, respectively. Results ISDB-based dental sealants exhibited typical initially smooth surfaces with depth of cure, Vickers hardness, compressive strength/modulus, water resorption/solubility, and flowability comparable to those of the commercial sealant and met the ISO standard for dental sealants and polymer-based restorative materials. Indirect cytotoxicity tests using an extract showed comparable viability among experimental ISDB-based materials and a commercial Bis-GMA-incorporated control. DNA synthesis in MCF-7 cells (a marker of estrogenicity) and the release of bisphenol A under enzymatic incubation were not detected in ISDB-based materials. Significance In conclusion, the comparable physico-mechanical properties of ISDB-based materials with their cytocompatibility and lack of estrogenicity suggest the potential usefulness of ISDBs as a newly developed and safe biomaterial.

With donor organs not readily available, the need for a tissue-engineered oesophagus remains high, particularly for congenital childhood conditions such as atresia. Previous attempts have not been successful, and challenges remain. Small intestine submucosa (SIS) is an acellular matrix material with good biological properties; however, as is common with these types of materials, they demonstrate poor mechanical properties. In this work, electrospinning was performed to mechanically reinforce tubular SIS with polylactic-co-glycolic acid (PLGA) nanofibres. It was hypothesised that if attachment could be achieved between the two materials, then this would (i) improve the SIS mechanical properties, (ii) facilitate smooth muscle cell alignment to support directional growth of muscle cells and (iii) allow for the delivery of bioactive molecules (VEGF in this instance). Through a relatively simple multistage process, adhesion between the layers was achieved without chemically altering the SIS. It was also found that altering mandrel rotation speed affected the alignment of the PLGA nanofibres. SIS-PLGA scaffolds performed mechanically better than SIS alone; yield stress improvement was 200% and 400% along the longitudinal and circumferential directions, respectively. Smooth muscle cells cultured on the aligned fibres showed resultant unidirectional alignment. In vivo the SIS-PLGA scaffolds demonstrated limited foreign body reaction judged by the type and proportion of immune cells present and lack of fibrous encapsulation. The scaffolds remained intact at 4 weeks in vivo, and good cellular infiltration was observed. The incorporation of VEGF within SIS-PLGA scaffolds increased the blood vessel density of the surrounding tissues, highlighting the possible stimulation of endothelialisation by angiogenic factor delivery. Overall, the designed SIS-PLGA-VEGF hybrid scaffolds might be used as a potential matrix platform for oesophageal tissue engineering. In addition to this, achieving improved attachment between layers of acellular matrix materials and electrospun fibre layers offers the potential utility in other applications. STATEMENT OF SIGNIFICANCE: Because of its multi-layered nature and complex structure, the oesophagus tissue poses several challenges for successful clinical grafting. Therefore, it is promising to utilise tissue engineering strategies to mimic and form structural compartments for its recovery. In this context, we investigated the use of tubular small intestine submucosa (SIS) reinforced with polylactic-co-glycolic acid (PLGA) nanofibres by using electrospinning and also, amongst other parameters, the integrity of the bilayered structure created. This was carried out to facilitate smooth muscle cell alignment, support directional growth of muscle cells and allow the delivery of bioactive molecules (VEGF in this study). We evaluated this approach by using in vitro and in vivo models to determine the efficacy of this new system.

Here, Fe ions-releasing mesoporous bioactive glass ultrasmall nanoparticles (Fe-BGn) were prepared by a facile one-pot ultrasonic-coupled sol–gel synthesis designed for use as ferroptosis-based bone cancer nanotherapeutics. The addition of 10% Fe2O3 to 85% SiO2 – 15% CaO by weight significantly reduced the particle size from about 65 nm to

Enabling angiogenesis is critical for the success of tissue repair therapies and the fate of tissue-engineered constructs. Although many biochemical signaling molecules have been used, their biological functions in vivo are known to be limited, mainly due to their short lifetime and poor activity. Matrices (or engineered biomaterials), beyond the biochemical signals, play pivotal roles in stimulating angiogenic processes. Here we discuss the proangiogenic effort taken to repair and regenerate various tissues including skin, bone, muscle and nerve, focusing on the roles of engineered matrices. This includes the design of pore structure and physico-chemical properties (nanotopology, stiffness, chemistry and degradability), the tailoring of matrices for proper presentation of growth factors and their crosstalks with adhesion ligands, the controlled and sustained delivery of angiogenic molecules and metallic ions, and the engineering of cells and construction of prevascularized tissues. Collectively, the materials-driven strategies are envisaged to tune the cell and tissue microenvironments where angiogenic events can be significantly favored through the matrix cues and properly presented or delivered signaling molecules and cells.

Providing a nanotopological physical cue in concert with a bioactive chemical signal within 3D scaffolds, while it being considered a promising approach for bone regeneration, has yet to be explored. Here, we develop 3D porous scaffolds that are networked to be a nanofibrous structure and incorporated with bioactive glass nanoparticles (BGn) to tackle this issue. The presence of BGn and nanofibrous structure (BGn + nanofibrous) substantially increased the surface area, hydro-affinity and protein loading capacity of scaffolds. In particular, the BGn released Si and Ca ions to the levels known to be biologically effective, offering the bone scaffold an ability to deliver therapeutic ions. The mesenchymal stem cells (MSCs) from rats exhibited significantly accelerated adhesion events including cell anchorage, cytoskeletal extensions, and the expression of adhesion signaling molecules on the BGn/nanofibrous scaffolds. The cells gained a more rapid proliferation and migration (penetration) ability over 2 weeks within the BGn + nanofibrous scaffolds than within either nanofibrous or BGn scaffolds. The osteogenesis of MSCs, as confirmed by the expressions of bone-associated genes and proteins, as well as the cellular mineralization was significantly stimulated by the BGn and nanofibrous topology in a synergistic manner. The behaviors of endothelial cells (HUVECs) including cell migration and tubule networking were also enhanced when influenced by the BGn and nanofibrous scaffolds (but more by BGn than by nanofiber). A subcutaneous tissue implantation of the scaffolds further evidenced the in vivo stimulation of neo-blood vessel formation by the BGn + nanofibrous cues, suggesting the possible promising role in bone regeneration. Taken together, the therapeutic ions and nanofibrous topology implemented within 3D scaffolds are considered to play synergistic actions in osteogenesis and angiogenesis, implying the potential usefulness of the BGn + nanofibrous scaffolds for bone tissue engineering.

Silica-based nanomaterials (SiNMs) with different forms, including nanoparticles, nanorods and nanofibers either with a dense, porous or hollow structure, have been demonstrated as fascinating platforms for the delivery of therapeutic molecules in the inorganic nanocarrier regime. This is primarily due to their unique physicochemical properties, which are effective and tunable for the uptake of different cargo molecules, as well as to their biological responses favorable for cells and tissues. Over the last decade, a substantial number of studies have exploited SiNMs with different shapes, sizes, mesopore structures and surface charges for use in cancer therapy, imaging and bioseparation. In particular, their surface can be functionalized with candidate molecules from dyes to drugs for theranostic purposes. Moreover, providing the carriers with intelligent modes, such as stimuli-responsiveness, and with multifunctionality through combining them with imaging particles (magnetic nanoparticles, quantum dots and carbon dots) improves their therapeutic and diagnostic potential. While many pioneering works in the SiNM systems have focused on cancer therapy, there is growing demand for using SiNMs in the area of regenerative medicine, for stem cell therapy and tracking, and for the repair of dysfunctional tissues. Here we review the most recent advances in SiMNs that are available for regenerative therapies. For this, we first give an overview of the general nanostructure forms and characteristics of the SiNMs from a physicochemical and biological point of view, and then deal with the intracellular uptake mechanism and toxicity issues. Finally, advanced designs of SiNMs to provide multifunctional and intelligent actions of loading and delivery of drugs and molecules are detailed, and then perspectives for their potential uses in regenerative medicine are provided.

Peripheral nerve injuries face some clinical obstacles and unsatisfactory functional outcomes. The slow regeneration rate of defected nerve delays functional recovery. To date, various therapeutic agents are used to enhance the survival and regeneration capacity of damaged neurons. Among these, nerve guide conduits held promise for peripheral nerve regeneration, through the physical guidance of the injured nerve across the lesions. Many natural and synthetic polymers are used to produce nerve conduits. Biopolymer-based biomaterials offer important options in control of structure, morphology, and chemistry as reasonable substitutes or mimics of extracellular matrix systems. Silk protein fibroin as a biocompatible natural polymer, possesses biodegradability, tunable mechanical properties, process ability, and suitable for the peripheral nerve conduits. This review highlights recent advances in the use of silk-based conduits for peripheral nerve regeneration. Further, the development of nerve conduit...

Objective Magnetic biomaterials have recently gained great attention due to their some intriguing cell and tissue responses. However, little attention has been given to the fields of dental tissue regeneration. In this sense, we aim to investigate the effects of magnetic nanofiber scaffolds on the human dental pulp cell (HDPC) behaviors and to elucidate the underlying signaling mechanisms in the events. Methods Magnetic nanofiber scaffolds incorporating magnetic nanoparticles at varying contents were prepared into nanofibrous matrices to cultivate cells. Cell growth by MTS assay, odontoblastic differentiation by alkaline phosphatase (ALP) activity, mineralization, and the mRNA expression of differentiation-related genes of HDPCs, in vitro angiogenesis by migration and capillary tube formation in endothelial cells on the conditioned medium obtained from HDPSCs in the presence or absence of scaffolds. Western blot analysis and confocal immunofluorescene were used to asses signaling pathways. Results The growth of HDPCs was significantly enhanced on the magnetic scaffolds with respect to the non-magnetic counterpart. The odontogenic differentiation of cells was significantly up-regulated by the culture with magnetic scaffolds. Furthermore, the magnetic scaffolds promoted the HDPC-induced angiogenesis of endothelial cells. The expression of signaling molecules, Wnt3a, phosphorylated GSK-3β and nuclear β-catenin, was substantially stimulated by the magnetic scaffolds; in parallel, the MAPK and NF-κB were highly activated when cultured on the magnetic nanofiber scaffolds. Significance This study is the first to demonstrate that magnetic nanofiber scaffolds stimulate HDPCs in the events of growth, odontogenic differentiation, and pro-angiogenesis, and the findings imply the novel scaffolds can be potentially useful as dentin-pulp regenerative matrices.

Providing an osteogenic stimulatory environment is a key strategy to construct stem cell-based bone-equivalent tissues. Here we design a stem cell delivering gel matrix made of collagen (Col) with bioactive glass nanocarriers (BGn) that incorporate osteogenic signaling molecule, fibroblast growth factor 18 (FGF18), a reservoir considered to cultivate and promote osteogenesis of mesenchymal stem cells (MSCs). The presence of BGn in the gel was shown to enhance the osteogenic differentiation of MSCs, possibly due to the therapeutic role of ions released. The mesoporous nature of BGn was effective in loading FGF18 at large quantity, and the FGF18 release from the BGn-Col gel matrix was highly sustainable with almost a zero-order kinetics, over 4 weeks as confirmed by the green fluorescence protein signal change. The released FGF18 was effective in accelerating osteogenesis (alkaline phosphatase activity and bone related gene expressions) and bone matrix formation (osteopontin, bone sialoprotein, and osteocalcin production) of MSCs. This was attributed to the bone morphogenetic protein (BMP) signaling pathway, where the FGF18 release stimulated the endogenous secretion of BMP2 and the downstream signal Smad1/5/8. Taken together, the FGF18-BGn/Col gel is considered an excellent osteopromoting depot to support and signal MSCs for bone tissue engineering.

Microspheres with a porous structure are promising cell carriers for tissue engineering. Here we explored monodisperse porous poly(caprolactone) (PCL) microspheres produced by a microfluidic system. The microfluidic device could generate homogeneous structured microspheres with excellent monodispersity. The microsphere size was tunable from 210 to 330 µm by adjusting the sheath flow rate from 170 to 330 µm. Camphene, used as a pore-generating material, was effective in creating open-channels, and the channel structure was significantly influenced by the solidification temperature and content of camphene. The size-tunable, monodisperse, and channeled-microspheres developed by using camphene and microfluidic device may be a potential platform in many areas, including biomolecule separation, drug delivery, and cell culture.

Biocompatible nanomaterials that allow for labeling cells and tissues with the capacity to load and deliver drug molecules hold great promise for the therapeutic-diagnostic purposes in tissue repair and disease cure. Here a novel nanoplatform, called C-dot bioactive organosilica nanosphere (C-BON), is introduced to have excellent theranostic potential, such as controlled drug delivery, visible-light imaging, and NIR photothermal activity. C-dots with a few nanometers were in situ generated in the Ca-containing organosilica mesoporous nanospheres through the sol-gel and thermal-treatment processes. The C-BON exhibited multicolor luminescence over a wide visible-light range with strong emissions and high photostability over time and against acidity and the possible in vivo optical imaging capacity when injected in rat subcutaneous tissues. Moreover, the C-BON showed a photothermal heating effect upon the irradiation of near-infrared. The C-BON, thanks to the high mesoporosity and existence of Ca(2+) ions, demonstrated excellent loading capacity of anticancer drug doxorubicin (as high as 90% of carrier weight) and long-term (over a couple of weeks) and pH/NIR-dependent release ability. The C-BON preserved the compositional merit of Ca-Si glass, having excellent bioactivity and cell compatibility in vitro. Taken all, the multifunctional properties of C-BON-multicolor luminescence, photothermal activity, and high drug loading and controlled release-together with its excellent bioactivity and cell compatibility potentiate the future applications in theranostics (chemotherapy and photothermal therapy with optical imaging).

Development of therapeutic strategies such as effective drug delivery is an urgent and yet unmet need for repair of damaged nervous systems. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) regulates axonal regrowth of central and peripheral nervous systems; its inhibition, meanwhile, facilitates axonal outgrowth of injured neurons. Here we show that nanotherapeutics based on mesoporous silica nanoparticles loading PTEN-inhibitor bisperoxovanadium (BpV) are effective for delivery of drug molecules and consequent improvement of axonal outgrowth. Mesoporous nanocarriers loaded BpV drug at large amount (27 μg per 1 mg of carrier), and released sustainably over 10 d. Nanocarrier-BpV treatment of primary neurons from the dorsal root ganglions (DRGs) of rats and mice at various concentrations induced them to actively take up the nanocomplexes with an uptake efficiency as high as 85%. The nanocomplex-administered neurons exhibited significantly enhanced axonal outgrowth compared with those treated with free-BpV drug. The expression of a series of proteins involved in PTEN inhibition and downstream signaling was substantially up-/down-regulated by the nanocarrier-BpV system. Injection of the nanocarriers into neural tissues (DRG, brain cortex, and spinal cord), moreover, demonstrated successful integration into neurons, glial cells, oligodendrocytes, and macrophages, suggesting the possible nanotherapeutics applications in vivo. Together, PTEN-inhibitor delivery via mesoporous nanocarriers can be considered a promising strategy for stimulating axonal regeneration in central and peripheral nervous systems.

Increasing amounts of metal-based implants are used for orthopedic or dental surgeries throughout the world. Still several implant-related problems such as inflammation, loosening and bacterial infection are prevalent. These problems stem from the immediate microbial contamination and failure of initial osteoblast adhesion. Additionally, bacterial infections can cause serious and life-threatening conditions such as osteomyelitis. Here, antibiotic (gentamicin)-loaded silk protein fibroin (non-mulberry silkworm, Antheraea mylitta) nanoparticles are fabricated and deposited over the titanium surface to achieve sustained drug release in vitro and to alter the surface nano-roughness. Based on the altered surface topography, chemistry and antibacterial activity, we conclude that the nanoparticle-deposited surfaces are superior for osteoblast adhesion, proliferation and differentiation in comparison to bare Ti. This method can be utilized as a cost-effective approach in implant modification.Titanium-based implants are commonly used in the field of orthopedics or dentistry. Surface modification of an implant is vital to ensure osseointegration. In this article, the author investigated the use of silk protein fibroins for metal surface modification and also for drug delivery against bacteria. The encouraging data should provide a new method in terms of nanotechnology in the respective clinical fields.

Magnetism has recently been implicated to play significant roles in the regulation of cell responses. Allowing cells to experience a magnetic field applied externally or scaffolding them in a material with intrinsic magnetic properties has been a possible way of utilizing magnetism. Here we aim to investigate the combined effects of the external static magnetic field (SMF) with magnetic nanocomposite scaffold made of polycaprolactone/magnetic nanoparticles on the osteoblastic functions and bone formation. The SMF synergized with the magnetic scaffolds in the osteoblastic differentiation of primary mouse calvarium osteoblasts, including the expression of bone-associated genes (Runx2 and Osterix) and alkaline phosphatase activity. The synergism was demonstrated in the activation of integrin signaling pathways, such as focal adhesion kinase, paxillin, RhoA, mitogen-activated protein kinase, and nuclear factor-kappaB, as well as in the up-regulation of bone morphogenetic protein-2 and phosphorylation of Smad1/5/8. Furthermore, the SMF/magnetic scaffold-stimulated osteoblasts promoted the angiogenic responses of endothelial cells, including the expression of vascular endothelial growth factor and angiogenin-1 genes and the formation of capillary tubes. When the magnetic scaffolds were implanted in mouse calvarium defects, the application of SMF significantly enhanced the new bone formation at 6 weeks, as revealed by the histological and micro-computed tomographic analyses. Current findings suggest that the combinatory application of external (SMF) and internal (scaffold) magnetism can be a promising tool to regenerative engineering of bone.

Hydroxyapatite (HA) mineral tubes developed through the replication of polymer nanofiber mesh were studied for loading and delivery of biological proteins. With varying heat-treatment temperature (500, 800 and 1100 °C), the physicochemical properties of the HA mineral tubes differed substantially, i.e., while crystallinity and crystallite size increased the surface area decreased with increase in the temperature. All mineral tubes retained negative surface charges (around −10 mV) at physiological conditions. Cytochrome C (cyt C), used as a model protein of being positively-charged, was adsorbed well onto the HA mineral tubes, with adsorption being saturated within a few hours. The adsorption amount was significantly higher in the case treated at lower temperature. The cyt C showed a similar release pattern from the HA mineral tubes, with an initial rapid release for a few hours followed by a reduced rate over ∼24 h. Results indicated the HA mineral tubes might be tailored to properly load and delivery biological molecules for bone repair.

Bone-mimetic scaffolds are receiving much interest as such scaffolds exhibit excellent biocompatibility and very close mimic to bone structure and composition. Here, novel bone-mimetic nanohydroxyapatite (nHA)/collagen (Col) porous scaffolds (nHA/Col) were prepared from surface silanized mesoporous nanobioglass (NBG)/Col hybrid scaffold by biomimetic mineralization. Surface silanized mesoporous NBG was prepared by ultrasound-assisted sol-gel method and post treatment with 3-aminopropyltriethylsilane (APTS). The surface silanized mesoporous NBG was characterized by transmission electron microscopy (TEM), transmission electron microscopy-selected area electron diffraction (TEM-SAED) and X-ray photoelectron spectroscopy (XPS). The physicochemical/mechanical characterizations of the scaffolds included scanning electron microscopy (SEM) and TEM imaging of micro/nanostructure, energy dispersive X-ray (EDX) analysis of chemical composition, TEM-SAED and X-ray diffraction/Attenuated total Reflectance-Fourier Infrared spectroscopy (XRD/ATR-FTIR) analyses of amorphous-to-crystalline transformations, thermogravimetric/differential scanning calorimetric (TGA/DSC) analyses of thermal behaviour , porosity and dynamic mechanical analyses. The presence of NBG in collagen fibrillar network enabled progressive growth of HA nanocrystals and generation of a novel bone-mimetic hybrid structures while preserving the highly porous structure of collagen scaffold. The crystallinity, crystallite size and crystal morphology of the grown HA nanocrystals were controllable by regulation of the mineralization time. Furthermore, the osteogenic properties of the non-mineralized (NBG/Col) and mineralized (nHA/Col) hybrid porous scaffolds were examined in vivo using critical-sized calvarial bone defect model in rat. Histological and micro-computed tomography (Micro-CT) analyses after 6 weeks of implantation revealed that the mineralized scaffolds possess excellent in vivo osteogenic potential compared to the non-mineralized one. Collectively, by using surface silanized mesoporous NBG hybridization with collagen fibrillar network, we successfully introduced a new approach for developing novel bone-mimetic nanohydroxyapatite/collagen hybrid scaffolds that possess significant potential for bone tissue regeneration.

Objective An anti-foaming and fast-setting gypsum for dental stone recently became available on the market. Interestingly, this product can be mixed by the cocktail shaking method, providing a more convenient way to obtain high reproducibility when fabricating error-free study models for digital dentistry. The aim of this study is to investigate setting time, surface bubble formation, and other gypsum characteristics of three dental stone products with different mixing methods. Methods Shake mix stone (SM), new plastone 2 white (NP), and Hi-Koseton (HK) were chosen. Using different mixing methods (cocktail shaking, hand mixing, hand mixing + vibrating, and hand mixing + vacuum process), the characteristics of dental stone were investigated according to ISO 6873. Powder size, morphology, and thermo/chemical analyses were performed. Results Regardless of the method of mixing, SM exhibited the fastest setting time (3–4 min) and the smallest number (˜10% versus HK) and area (˜30% versus HK) of surface bubbles among the investigated products, while setting expansion, mechanical properties such as compressive/impact strength and microhardness and detail reproduction before and after digital scanning were similar. A smaller size (˜1.5 μm) and unidentified additives were revealed as possible reasons for the above anti-foaming and fast-setting characteristics. Significance Anti-foaming and fast-setting characteristics of a developed gypsum for dental stone were confirmed even with shaking.

Implementing novel approaches for cancer therapy are under continuous progress, and bioactive glasses (BGs) and glass-ceramics show excellent potential in this regard. Although these materials have been mostly used as magnetic substances in hyperthermia approach, some of their subsets, i.e., mesoporous bioactive glasses (MBGs), have been recently proposed not only as magnetic materials but also as drug delivery systems for advanced treatment of bone cancer. Different types of MBGs including granular particles and three-dimensional (3D) scaffolds can be applied for cancer therapy. Based on the results obtained from in vitro studies, MBGs seem to have a bright future in the therapeutic strategies to combat cancer; however, their application in this field is still in its beginning, and more research needs to reveal all pros and cons of this newly proposed approach.

In the field of nanomedicine, drug-loaded nanocarriers that integrate nanotechnology and chemotherapeutics are widely used to achieve synergistic therapeutic effects. Here, we prepared mesoporous silica nanoparticles capped with cerium oxide nanoparticles (COP@MSN) wherein a pH trigger-responsive mechanism was used to control drug release and intracellular drug delivery. We blocked the mesopores of the carboxyl-functionalized MSN with aminated COP. These pores could be opened in acidic conditions to release the loaded drug, thus establishing a pH-responsive drug release system. We loaded doxorubicin (DOX) as anticancer biomolecule into the pores of MSN and capped with COP. The COP@DOX-MSN system showed a typical drug release profile in an acidic medium, which, however, was not observed in a neutral medium. In vitro studies using cancer cell line (HeLa) proved that the COP@DOX-MSN entered efficiently into HeLa cells and released DOX to the level sufficient for cytotoxicity. The cytotoxic effect of COP in cancer cells was facilitated by the pro-oxidant property of COPs, which considerably raised the reactive oxygen species (ROS) level, thereby leading to cellular apoptosis. The combination of DOX with COP (COP@DOX-MSN) showed even higher ROS level, demonstrating a cytotoxic synergism of drug and nanoparticle in terms of ROS generation. Collectively, the COP@DOX-MSN is considered useful for cancer treatment with the combined capacity of pH-controlled drug delivery, chemotherapeutics, and redox activity.

Multiphasic bionanocomposites have been highlighted in the biotechnology field since they have offered mechanical flexibility during operation. This interest has been increased mainly through polymer/ceramic/metal manipulation techniques and modifications in formulation. Recently, a number of studies on bionanocomposites have been examined due to their favorable mechanical properties and cellular activities when compared to the neat polymers or polymer blends. This paper critically reviews recent applications of bionanocomposites for regeneration of pulp-dentin complex, periodontal ligament, and alveolar bone, and substitute of enamel in dentistry.

Over the past few years, attention has been focused on the therapeutic roles in designing bone scaffolds for successful repair and regeneration. Indeed, biologically dynamic events in the bone healing process involve many of the molecules and cells adherent to the scaffold. Recent bone scaffolds have been designed considering intrinsic chemical and physical factors and exogenous/extrinsic cues that induce bone regeneration. Here, we attempt to topically review the current trends and to suggest featured strategies for the design of therapeutically relevant bone scaffolds taking into account recent studies and applications. info:eu-repo/semantics/publishedVersion

Biocompatible nanostructured surfaces control the cell behaviors and tissue integration process of medical devices and implants. Here we develop a novel biocompatible nanostructured surface based on mesoporous silica nanotube (MSNT) by means of an electrodeposition. MSNTs, replicated from carbon nanotubes of 25 nm × 1200 nm size, were interfaced in combination with fugitive biopolymers (chitosan or collagen) onto a Ti metallic substrate. The MSNT-biopolymer deposits uniformly covered the substrate with weight gains controllable by the electrodeposition conditions. Random nanotubular networks were generated successfully, which alongside the high mesoporosity provided unique nanotopological properties for the cell responses and the loading/delivery of biomolecules. Of note, the adhesion and spreading behaviors of mesenchymal stem cells (MSCs) were significantly altered, revealing more rapid cell anchorage and extensive nanofilopodia development along the nanotubular networks. Furthermore, the nanotubular surface improved the loading capacity of biomolecules (dexamethasone and bovine serum albumin) up to 5-7 times. The release of the biomolecules was highly sustained, exhibiting a diffusion-controlled pattern over 15 days. The therapeutic efficacy of the delivered biomolecules was also confirmed in the osteogenic differentiation of MSCs. While in vivo performance and applicability studies are needed further, the current biocompatible nanostructured surface may be considered as a novel biointerfacing platform to control cellular behaviors and biomolecular delivery.

A comparative study of nanofibrous scaffolds with inclusion of nonmulberry silk protein fibroin is presented for application in bone tissue engineering. Introduction of silk fibroin into the scaffolds is carried out in two ways: by electrospinning blend of poly(e-caprolactone) (PCL) and by grafting fibroin on aminolyzed electrospun nanofibrous PCL. Verification of aminolysis was provided by confocal laser microscopy of rhodamine B isothiocyanate tagged substrates. Absorbance spectroscopy of the products of the reaction between NH2 groups and ninhydrin was used for quantification of aminolysis. Presence of nitrogen on the substrates was established using energy dispersive X-ray while scanning electron microscopy was used to substantiate their nanofibrous morphology. Evaluation of ATR-FTIR results showed that secondary structure of fibroin was preserved in the respective substrates. Presence of fibroin improves hydrophilicity, measured by dynamic contact angle, and surface roughness, topography viewed by atomic force microscopy. These characteristics support cell growth and proliferation. The mechanical strength of the scaffolds is enhanced due to presence of fibroin. Different biophysical characterizations indicate better hydrophilicity, higher nitrogen content, and higher surface roughness of the fibroin grafted scaffolds. Both fibroin-grafted and fibroin-blended scaffolds successfully support activity and viability of human osteoblast like cells. Cell cycle analysis, alkaline phosphatase assay and Alizarin red S staining are used to substantiate cell cycle pattern, proliferation and resultant neo-matrix generation on the scaffolds respectively. The results show that fibroin grafted matrices are better at supporting cell adhesion, growth, and proliferation. The findings demonstrate advantages of fibroin blended and grafted matrices for use in bone tissue engineering applications.