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The advent of three-dimensional (3D) bioprinting offers a feasible approach to construct complex structures for soft tissue regeneration. Carboxymethyl cellulose (CMC) has been emerging as a very promising biomaterial for 3D bioprinting. However, due to the inability to maintain the post-printed stability, CMC needs to be physically blended and/or chemically crosslinked with other polymers. In this context, this study presents the combination of CMC with xanthan gum (XG) and hyaluronic acid (HA) to formulate a multicomponent bioink, leveraging the printability of CMC and XG, as well as the cellular support properties of HA. The ionic crosslinking of printed constructs with iron(III) via the metal-ion coordination between ferric cations and carboxylate groups of the three polymers was introduced to induce improved mechanical strength and long-term stability. Moreover, immortalized human epidermal keratinocytes (HaCaT) and human foreskin fibroblasts (HFF) encapsulated within iron-crosslinked printed hydrogels exhibited excellent cell viability (more than 95%) and preserved morphology. Overall, the presented study highlights that the combination of these three biopolymers and the ionic crosslinking with ferric ions is a valuable strategy to be considered for the development of new and advanced hydrogel-based bioinks for soft tissue engineering applications. [ABSTRACT FROM AUTHOR]

Plasma electrolytic oxidation (PEO) is a well-established technique for the treatment of titanium-based materials. The formed titania-PEO surface can improve the osseointegration properties of titanium implants. Nevertheless, it can not address bacterial infection problems associated with bone implants. Recently, 2-dimensional (2D) materials such as graphene oxide (GO), MXene, and hexagonal boron nitride (hBN) have received considerable attention for surface modifications showing their antibacterial properties. In this paper, a comparative study on the effect of partial deposition of these three materials over PEO titania substrates on the antibacterial efficiency and bioactivity is presented. Their partial deposition through drop-casting instead of continuous film coating is propsed to simultaneously address both antibacterial and osseointegration abilities. Our results demonstrate the dose-dependent nature of the deposited antibacterial agent on the PEO substrate. GO–PEO and MXene–PEO samples showed the highest antibacterial activity with 70 (±2) % and 97 (±0.5) % inactivation of S. aureus colonies in the low concentration group, respectively. Furthermore, only samples in the higher concentration group were effective against E. coli bacteria with 18 (±2) % and 17 (±4) % decrease in numbers of colonies for hBN–PEO and GO–PEO samples, respectively. Moreover, all antibacterial samples demonstrated acceptable bioactivity and good biocompatibility, making them a considerable candidates for the next generation of antibacterial titanium implants. [ABSTRACT FROM AUTHOR]

The rapid surface oxidation of phosphorene under ambient conditions is considered to be a serious issue for many applications, but is used here as a strategy to achieve efficient heteroatom doping. Highly crystalline nitrogen-doped phosphorene (N-phosphorene) is prepared using a combination of ball milling and microwave techniques. The prepared N-doped phosphorene nanosheets showed outstanding electrocatalytic performance as a new type of non-metallic catalyst for nitrogen (N2) to ammonia (NH3) conversion, with an NH3 yield rate and faradaic efficiency (FE) of up to 18.79 μg h−1 mgCAT−1 and 21.51%, respectively, at a low overpotential (0 V) versus the reversible hydrogen electrode (RHE). Density functional theory calculations revealed that the high nitrogen reduction reaction (NRR) FEs originate from the increased hydrophobicity at the N and O doped phosphorene surfaces, which in turn hinders the competing hydrogen evolution reaction (HER) in an alkaline environment and promotes the NRR. This work not only introduces an efficient strategy to chemically functionalize 2D phosphorene, but also opens a new avenue in using N-doped phosphorene nanosheets as a metal-free catalyst. [ABSTRACT FROM AUTHOR]

Bioprinting is an emerging powerful fabrication method, which enables the rapid assembly of 3D bioconstructs with dispensing cell-laden bioinks in pre-designed locations. However, to translate this technology into real applications, there are still a number of challenges that need to be addressed. First, the current inks are generally composed of polymeric materials with poor electrical conductivity that mismatches with the native tissue environment. The second challenge associated with the 3D bioprinting of hydrogel-based bioinks is the fabrication of anatomical-size constructs without any loss of shape fidelity and resolution. To address these challenges, in this work, we introduced a biocompatible bioink associated with current 3D bioprinting by combining methylcellulose and kappa-carrageenan (MC/κCA) hydrogels with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) conducting polymers. The prepared ink exhibited highly thixotropic behaviour, which could be tuned via changing the concentration of MC and κCA to obtain easy printing with high shape fidelity. The ink was able to fabricate physiological-scale constructs without requiring a secondary support bath. In addition, varying the concentration of PEDOT:PSS could control the electrical conductivity of the ink. Moreover, the encapsulated human embryonic kidney 293 (HEK-293) cells in bulk hydrogels and 3D bioprinted structures maintained high cell viability (>96%) over a week, confirming the in vitro biocompatibility of the ink. Overall, these findings indicate that the MC/κCA/PEDOT:PSS bioink can be promising in biomedical applications, which improved the electroconductivity of bioinks and can exploit the advantage of conductive polymers in the 3D bioprinting technology. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) antimonene nanosheets are prepared using a combination of ball milling and sonication-based liquid exfoliation and are used as an efficient electrocatalyst for the nitrogen reduction reaction (NRR). In 0.1 M KOH, a high NH3 yield of 180.4 μg h−1 mgCAT−1 and faradaic efficiency (FE) of 11.6% are achieved using our antimonene nanosheets. Theoretical calculations suggest that the oxidized species of antimonene act as the active catalytic sites for the NRR process. This work opens up a new avenue towards the development of 2D electrocatalysts for clean energy. [ABSTRACT FROM AUTHOR]

Current commercially available phosphorus (P) fertilisers, which are highly soluble salts, are susceptible to surface runoff to waterways, and leaching to groundwaters where soils are light/medium textured. Here, we report the synthesis of a graphene oxide (GO)/iron (GO–Fe) composite, a promising carrier for loading P. The GO–Fe carriers loaded with P acted as slow release fertilisers with tunable loading/release properties. The amount of P loaded onto the GO–Fe composite was 15%, similar to commercial products. Investigation of the morphology and spectroscopic and chemical analysis revealed a complex loading mechanism of Fe onto GO. Iron, as an active center for P sorption, could interact with the oxygen functional groups at the edge of GO sheets as well as the π-electron system of the aromatic part of GO. Column perfusion studies, visualisation of P diffusion in soils and chemical analysis of soils after diffusion showed the composites to have slow-release properties. Pot experiments using wheat and our composites resulted in the same yield as using highly soluble commercial fertiliser. [ABSTRACT FROM AUTHOR]

Halloysite nanotubes were activated via co-calcination of halloysite and the precursors of lanthanum oxycarbonate (LO), generating reactive alumina nanoparticles and uniformly anchoring LO nanoparticles to halloysite surfaces. The resulting LO–alumina combination exhibits record-high phosphate adsorption capacity as well as excellence in adsorption selectivity and sewage phosphate removal. [ABSTRACT FROM AUTHOR]

A synergistic host–guest coupling is exploited to disorder nano-kaolinite unit layers to form Al2O3 nanoparticles, which act as activated adsorptive sites; meanwhile, the coupling enables La-based nanoparticles to anchor homogenously on the nano-kaolinite surfaces, fully utilizing their adsorption ability. The activated hybrid nanostructures exhibit an excellent phosphate adsorption capacity. [ABSTRACT FROM AUTHOR]

With the increasing demand for low-cost and more efficient dental implants, there is an urgent need to develop new manufacturing approaches and implants with better osseointegration performance. 3D printing technology provides enormous opportunities for the rapid fabrication of a new generation of patient-tailored dental implants with significantly reduced costs. This study presents the demonstration of a unique model of titanium implants based on 3D printing technology with improved osseointegration properties. Titanium alloy (Ti6Al4V) implants with a micro-structured surface are fabricated using a selective laser-melting process followed by further nano-structuring with electrochemical anodization to form titania nanotubes (TNT) and subsequent bioactivation by a hydroxyapatite (HA) coating. The osseointegration properties of the fabricated implants were examined using human primary osteoblasts and cell line models. The results showed significantly increased protein adsorption, cell adhesion and cell spreading. The expression of the late osteoblast/osteocyte genes GJA1 and PHEX was also enhanced, indicating a cell maturation effect and the promotion of mineralization on the surface. These results suggest that 3D printing technology combined with electrochemical nano-structuring and HA modification is a promising approach for the fabrication of Ti implants with improved osseointegration and provides potential alternatives to conventional dental implants. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles have been extensively used for energy production in fuel cells; however, the different phases of iron oxide have not been adequately investigated for their effect on the oxygen reduction reaction (ORR). The low temperature synthesis of four kinds of iron oxide nanoparticles with different phases was incorporated inside 3D reduced graphene oxide (rGO) aerogels and their electrochemical, catalytic and electron transfer properties were determined for ORR. The results showed that, at low potentials (0.20 V), rGO composites containing magnetite, maghemite and goethite catalyse ORR via four-electron transfer kinetics while hematite facilitated two-electron transfer kinetics. At higher potentials (0.70 V), all four catalysts proceeded via a two-electron pathway. [ABSTRACT FROM AUTHOR]

In this study, a magnetic core–shell modified tumor-targeting nanocarrier (MNPs-PEG–TRA) was engineered and demonstrated for the efficient in vitro and in vivo hyperthermia treatment of breast cancer. Magnetic nanoparticles were used as the initial nanocarriers and modified via PEGylation followed by immobilization of Trastuzumab (TRA) with tumor-targeting function towards cancer cells. The hyperthermia performance of the developed targeting drug delivery system was explored using an in vitro study with SK-BR-3 cancer cells and an in vivo study using animal models (mouse) with DMBA-induced breast cancer. The average size of the engineered system was about 100 nm and its zeta potential was about +13 mV, whereby the stability of the system in biological media is enormously enhanced while the possibility of it being removed via the immune system is diminished. The investigation was pursued based on comparing the changes in growth inhibition rates of HSF 1184, MDA-MB-231, MDA-MB-468 and SK-BR-3 cell lines at different temperatures (37 °C, 40 °C, 42 °C, and 45 °C). Compared with bare MNPs and MNPs-PEG, a remarkably enhanced hyperthermia effect using MNPs-PEG–TRA was observed not only in cultured SK-BR-3 cells in vitro but also in an in vivo DMBA tumor bearing mice model. These results are attributed to an about 4 fold higher concentration of MNPs-PEG–TRA carriers in the tumor site compared to the other organs confirming the considerable potential of the magnetic tumor-targeting hyperthermia concept for breast cancer treatment. [ABSTRACT FROM AUTHOR]

pH stimuli responsive drug delivery platforms that can target specific locations along the gastrointestinal tract hold great promise for colorectal cancer therapy. Herein, we present a facile approach to produce microfluidic engineered pH-sensitive magnetic microspherical carriers containing multifunctional therapeutic payloads for synergistic treatment of colorectal cancer. Chemotherapeutics, 5 fluorouracil (5FU) and curcumin (CUR), were chosen due to their synergistic effect for colorectal cancer treatment and prevention. Drugs were loaded onto naturally derived porous silicon nanoparticles (SiNPs) and magnetic bacterial iron oxide nanowires (BacNWs), which acted as drug nanocontainers and magnetic elements, respectively. Drug loaded SiNPs and BacNWs were then encapsulated into polymeric microspheres using droplet-based microfluidics. To ensure controlled drug delivery into the desired site of action (colon and rectum), the microspheres were fabricated using hypromellose acetate succinate polymers, which are insoluble in the acidic medium of the stomach (i.e. pH 1.2) but soluble at basic pH (colon and rectum). Our results confirmed that the microspheres exhibit a narrow size distribution (CV ＞ 5%) with precise size control. Moreover, in vitro dissolution and drug release data confirmed their pH-responsive properties. Motivated by these results, we explored the biocompatibility of microspheres using human RAW 264.7 macrophages. The results revealed the safety of drug free microspheres up to 1000 μg mL−1. Finally, the synergistic action of 5FU and CUR loaded microspheres was investigated on SW480 colon adenocarcinoma cells. [ABSTRACT FROM AUTHOR]

Successful conversion of diatomites (SiO2) into silicon diatoms was achieved via the magnesiothermic reduction method followed by deposition of MnO2 nanosheets to fabricate unique 3D silicon-diatom@MnO2 electrodes and demonstrate their application for high-performance supercapacitors. The synergy between the microporous diatom structure and layered MnO2 nanosheets was found to produce excellent electrochemical performance evidenced by high specific capacitance (341.5 F g−1 at a current density of 0.5 A g−1), good rate capability (47.7% retention with current increases around 20 times) and steady cycling performance (84.8% remained after 2000 cycles). The prepared asymmetric supercapacitor based on silicon diatom@MnO2 nanosheets as a positive electrode and active graphene oxide (AGO) as a negative electrode delivered a maximum power density of 2.22 kW kg−1 and an energy density of 23.2 W h kg−1, which is superior to many other silicon-based and MnO2-based materials. These outstanding performances are attributed to the unique 3D microstructures, good conductivity of silicon diatoms and the highly porous surface formed by interconnection of MnO2 nanosheets. Considering the low cost of initial materials and simplicity of the fabrication process, these silicon diatom@MnO2 nanosheet electrodes have significant potential to be used as an electrode material for inexpensive and high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Diatom silica, a 3-dimensional (3D) natural biomaterial generated from single cell algae with unique nano- and micro-morphologies and patterns is shown to have several exceptional structural, mechanical, optical, photonics, transport, and chemical properties optimized through millions of years of evolution. Diatom nanotechnology, a new research field, emerged recently to explore and apply this material and its properties across numerous fields including biology, biophotonics, nanofluidics, molecular separation, sensors, biosensors, adsorption, drug delivery, nanofabrications, and energy. Due to its unique 3D porous hierarchical architecture, high surface area and ability to be combined or converted to other conductive and semiconductive nanomaterials, diatom silica received significant research attraction as a low cost natural electrode material for energy storage and production. Herein, we present the recent development in this field, showing new concepts using diatom-based composites for energy applications in supercapacitors, batteries, solar cells and other energy based devices. [ABSTRACT FROM AUTHOR]

Electrochemically engineered anodic alumina nanotubes (AANTs) have recently shown good in vitro biocompatibility. However, in vivo toxicological and pathological studies are required to clarify the bio-safety of this novel nanomaterial. Herein, we present a pioneering pilot toxicity study on AANTs in immune-competent murine models (Balb/c mice, 8 weeks). AANTs were administered by intravenous (IV) injection and subcutaneous (SC) implantation routes considering the future toxicological implications associated with this nanomaterial for potential biomedical applications. AANTs, 736 nm long and 90 nm in outer diameter, were chosen as a nanomaterial model. We demonstrate that IV injected AANTs do not have any effect on the mortality or body weight of these animal models within 28 days at three different doses (20, 50, 100 mg kg−1). The biodistribution of AANTs characterized by fluorescence imaging and inductively coupled plasma revealed the accumulation of AANTs in the liver and spleen after IV injection. When AANTs were injected intravenously, the highest dose of 100 mg kg−1 caused moderate hepatotoxicity, identified by histopathological analysis. The implantation of AANTs subcutaneously and directly under the skin leads to an inflammatory response, which is a typical foreign body reaction. Taken together, this work provides new insights into the toxicity patterns of new nanomaterials such as AANTs and establishes a rationale for the design of functional AANTs for future biomedical applications. [ABSTRACT FROM AUTHOR]

Conductive nanostructured composites combining an epoxy polymer and graphene have been explored for applications such as electrostatic-dissipative, anti-corrosive, and electromagnetic interference (EMI) shielding, stealth composite coating and specifically for sensors. For many of these applications, the limits of dispersion of graphene nanosheets and the interface between fillers and matrices have affected their electrical, structural and mechanical properties. To address these problems, we present the use of a dimethylbenzamide (DMBA)-based hardener to modify the surface of reduced graphene oxide (RGO) and create a 3D architecture with a micro-porous structure. DMBA is applied to provide two functions: one is to act as a stabilizer to avoid restacking of graphene sheets during the reduction process, and the second is to provide a linkage between RGO and epoxy for the formation of homogeneous nanocomposites. Thin films of conductive polymer graphene composites (CPCs) were prepared using a simple doctor blade method, while piezoresistive sensors were prepared by spraying to demonstrate their application for mechanical strain sensing. The electrical properties of the composites as a function of graphene fillers were shown to significantly increase from 1012Ω sq−1 for neat epoxy to 106Ω sq−1 for 2 wt% RGO in epoxy composites, while the modulus calculated using nanoindentation exhibited a 43.3% enhancement from 3.56 GPa for epoxy to 6.28 GPa for the composites containing 2 wt% graphene. The results of piezo-resistive performance for mechanical strain sensing under both static and dynamic strain modes showed good sensitivity with a gauge factor (GF) of 12.8 and a fast response time of 20 milliseconds. A minor loading/unloading hysteresis loop after 1000 cycles indicated good reversibility and reproducibility of the sensors. Excellent reproducibility, long-term stability and reliability of the sensing devices are confirmed working without decay of sensitivity after a 6-month exposure to ambient atmosphere. The results obtained suggest that these types of piezo-resistive sensors based on RGO/epoxy CPCs due to their simple, scalable and low cost production could lead to the development of high-performance mechanical strain sensors for a broad range of applications including real-time monitoring, wearable electronics, and structural health monitoring (SHM). [ABSTRACT FROM AUTHOR]

3-Dimensional (3D) composites based on a unique combination of MnO2-nanostructures, graphene oxide nanosheets and porous Diatomaceous Earth (DE) microparticles (GO–DE@MnO2) were synthesized and explored for application in high-performance supercapacitors. To explore the influence of the structural properties of MnO2 nanostructures on supercapacitor performances, several MnO2 structures with nanosheet and nanowire morphologies were synthesized and characterized. The prepared GO–DE@MnO2 composites with MnO2 nanosheets due to their higher conductivity and higher surface area showed a larger specific capacitance of 152.5 F g−1 and a relatively better cycle stability (83.3% capacitance retention after 2000 cycles at a scan rate of 2 A g−1), indicating great potential for application in supercapacitors. [ABSTRACT FROM AUTHOR]

The conversion of titania (TiO2) nanotubes into titanium (Ti), while preserving their nanotubular structures, is demonstrated. Their application as bone implants and electrodes for combined local drug delivery and electrical stimulation therapy is proposed. [ABSTRACT FROM AUTHOR]

The toxic paradigms of chemotherapeutic drugs and nanoparticles are tightly linked. Whereas uncontrolled exposure of living systems to therapeutics/nanomaterials leads to toxicity, selective induction of cytotoxicity in cancer cells helps in the fight against cancer. The increasing understanding of nanotoxicity paradigms has recently resulted in important benchmarks for the safe design of nanomaterial-based drug delivery systems aiming to fight cancer. In this context, this review aims to compile and present recent advances, outcomes and interconnections between nanomaterial-based drug delivery and nanotoxicity disciplines in order to provide a comprehensive guidance for future research. First, the basic concepts and mechanisms of nanomaterial-based drug delivery and nanotoxicity are introduced. Second, we present a detailed classification of drug delivery strategies and nanotoxicity paradigms, supported by the most recent research studies with a special focus on the interconnections between nanotoxicity and drug delivery research, which are highlighted in order to explore future opportunities for developing advanced therapeutic approaches. Finally, this review is concluded with future prospects on the use of nanoparticles for manipulating the behavior of cells and animals. [ABSTRACT FROM AUTHOR]

Electrochemically engineered nanoporous anodized aluminium oxide (AAO) prepared on aluminium (Al) foil by anodization process was employed as a platform for loading different forms of selenium (Se) in order to investigate their release behaviour and potential application for localized drug delivery targeting bone cancer. Several forms of Se including inorganic Se (H2SeO3), organic Se ((C6H5)2Se2), metallic Se, their chitosan composites, electrodeposited (ED) and chemical vapour deposited (CVD) Se were explored and combined with another model drug (indomethacin). Structural, drug-loading and in vitro drug-releasing characteristics of prepared Se-based drug delivery carriers were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and UV-visible spectroscopy (UV-Vis), respectively. Sustained and controlled release of Se was demonstrated through chitosan-composites of inorganic, organic or metallic forms of Se loaded into nanoporous AAO carriers. Cell viability studies showed decreasing toxicity to cancer cells in the order: inorganic Se ＞ ED Se ＞ CVD Se ＞ metallic Se ＞ organic Se. The study suggests new alternatives for localized drug treatment based on low-cost nano-engineered carriers loaded with Se having anti-cancer properties. [ABSTRACT FROM AUTHOR]

Graphene based materials have attracted great interest in the development of new and advanced protective coatings due to their excellent chemical resistance, impermeability to gases, adsorption capacity, anti-bacterial properties, mechanical strength, lubricity and thermal stability. This review presents current progress and discusses the major challenges and future potential of graphene in the field of protective coatings. This review specifically focuses on the most recent advances in the application of graphene for corrosion resistant coatings, flame retardant coatings, wear/scratch resistant coatings, anti-fouling coatings, pollutant adsorption coatings and anti-septic coatings. [ABSTRACT FROM AUTHOR]

A needle puncture approach using nanoengineered aluminium (Al) wires as drug-releasing implants is explored for localized drug delivery in bone using an ex vivo bone reactor. The wire implants were prepared by electrochemical anodization with the formation of a thin nanoporous alumina (NPA) layer on their surface and pore diameters of 30–35 nm and pore lengths of 10–60 μm. An in vitro drug release study of a model drug from the implants, prepared with different thicknesses of NPA layers (pore lengths), showed a considerable influence on drug release characteristics. The results confirmed that by controlling the pore length it is possible to tune the drug releasing performance of the implants and achieve a sustained release for an extended period. The biocompatibility study of the implants evaluated using human osteoblast cell culture showed strong growth of cells, their spreading and their adhesion to the implant surface. The drug loaded wire implants inserted inside bone by a needle puncture approach are evaluated for ex vivo drug release inside bone using a bone reactor (Zetos). The results demonstrated consistent and slow drug release from implants and distribution inside bone monitored in situ using a live imaging technique. The cross-sectional study of inserted wire implants after an extended period of release confirmed stable and unchanged NPA morphology. Histology of bone in contact with implants indicates the presence of viable osteocytes along the inserted area indicating that this method is a reliable approach and NPA wire implants are harmless devices. Overall, this study demonstrates that needle guided implantation of nanoengineered and drug loaded porous wires could be used as a new drug releasing implants for localized bone therapy and treatment of bone disease such as bacterial infection, healing, and potentially bone cancer. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate the synthesis of size- and shape-controlled MnO2 nanostructures by replica molding from diatom silica structures for high-performance supercapacitors. Three types of hierarchical hollow MnO2 patterns with different three-dimensional (3D) structures, shapes and large surface areas were successfully prepared from three diatom species by a template-assisted hydrothermal process. The extraordinary precision and nano-scale resolution of 3D replications of complex biological architecture from diatoms to artificial MnO2 structures are confirmed. Detailed electrochemical measurements reveal that the Melosira-type MnO2 pattern exhibits not only a high specific capacitance of 371.2 F g−1 at a scan rate of 0.5 A g−1, but also relatively good cycle stability (93.1% capacitance retention after 2000 cycles at a scan rate of 5 A g−1), demonstrating a promising application as supercapacitor electrode materials. [ABSTRACT FROM AUTHOR]

The contamination of aqueous systems with phosphates has considerable environmental concerns and here, we present a new method for phosphate removal based on graphene aerogel composites. 3-Dimensional graphene aerogels decorated with goethite (αFeOOH) and magnetite (Fe3O4) nanoparticles were synthesised and their application in capturing phosphates in water was successfully demonstrated. The prepared aerogels showed superior capacity to remove up to 350 mg g−1 at an initial phosphate concentration of 200 mg L−1 from water. The Freundlich model was suitable to describe the adsorption mechanism of phosphate removal by the graphene–iron nanoparticle aerogels through both mononuclear and polynuclear adsorption onto the nanosized αFeOOH and Fe3O4 nanoparticles. These new phosphate adsorbents can be produced in different forms and dimensions, using a simple, green and scalable process, and have the potential to be applied for practical applications in phosphate management of waste and storm water. [ABSTRACT FROM AUTHOR]

The structural engineering of titania nanotubes (TNTs) using electrochemical anodization was performed to generate periodically modulated (p-TNTs) internal structures by applying an oscillatory voltage during the anodization process to demonstrate their improved drug-loading and drug-releasing properties. Drug loading and in vitro drug release studies compared with conventional TNTs with flat structures suggested considerable improvement with increased drug loading, reduced burst release and extended drug release for over 2 weeks. Furthermore, p-TNTs arrays were fractured by ultrasonication into liberated TNTs capsules and their potential applications as drug micro/nano-carriers for targeted and localized drug delivery is proposed. The presented electrochemical approach for structural engineering of TNTs provides new prospects in designing TNTs drug releasing implants with advanced drug-loading/release characteristics for localized drug delivery. Such implant modifications can further be tailored to cater for various implant challenges and bone therapies like: inflammation, infection and poor implant integration. [ABSTRACT FROM AUTHOR]

The need for more efficient drug delivery strategies to treat resilient diseases and the rise of micro and nanotechnology have led to the development of more sophisticated drug-releasing implants with improved capabilities and performances for localised and controlled therapies. In recent years, implantable drug-releasing systems have emerged as an outstanding alternative to conventional clinical therapies. This new breed of implants has shown promising capabilities to overcome the inherent problems of conventional implants and therapies, making clinical treatments more efficient with minimal side effects. Recent clinical trials have demonstrated that this technology can improve the life of patients and increase their life expectancy. Within this context, this review is aimed at highlighting the different types and concepts of drug-releasing implants incorporating new nanomaterials and nanotechnology-based devices. Furthermore, the principles on which these drug-releasing implants are based as well as their advantages and limitations are discussed in detail. Finally, we provide a future perspective in the development of implantable clinical drug-delivery systems based on micro and nanotechnology. [ABSTRACT FROM AUTHOR]