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Hybrid nanomaterials possess integrated multi-components to syncretize various properties and functions within a single entity. Owing to this synergistic effect, they promise efficient anti-cancer therapy. In line with this target, we produced stimuli-responsive nanoparticle-nanofiber hybrids (NNHs) via embedding photoresponsive natural melanin nanoparticles (MNPs) within a biocompatible polycaprolactone (PCL) nanofiber matrix. Electrospinning was performed to produce monolithic and core-shell structured NNHs using a single and a coaxial nozzle. The NNHs were upgraded to drug delivery systems by model hydrophilic drug-ampicillin (amp)-loading. The drug release results showed that monolithic PCL meshes displayed a burst release, whereas nanohybrid formation with MNPs improved the release profile toward Fickian diffusion. Core-shell NNH presented a more sustained drug release profile than its MNP-free replica and monolithic NNH because its encapsulating shell layer hindered the diffusion of the drug. The photodynamic therapy accompanied by UV-A-irradiation on monolithic and core-shell NNHs yielded up to 34 % and 37 % malignant melanoma cell death. Moreover, this study proved the potency of MNPs-enhanced NNHs in drug delivery and photodynamic therapy applications. Even so, more efforts should be concerted to unlock unknown features of the NNHs, which have the power to advance emerging areas, including but not limited to material science, biosensing, and theranostics.

Achieving biological softness and flexibility has been a critical challenge for bio-electronic materials in areas of implantable bionic interfaces and wearable devices. Unlike inherently rigid electronic materials, bioengineered interfaces or scaffolds require stretchable softness as well as functional porosity for selective ionic transports. Toward this goal of providing electrically conducting biomaterials, we report ultrathin single-walled carbon nanotube (SWNT) layer coating on biodegradable polycaprolactone (PCL) membranes via layer-by-layer (LBL) assembly technique. The resulting membranes have unique, hierarchically structured 3D network of conductive paths around asymmetric nano-/micro-pores, providing softness as well as stretchable, anisotropic electrical conductivity. The strain sensors embedded on the membrane also demonstrate bending directional sensitivity as well as piezoresistivity with tunable Gauge Factor (GF) in the ranges of 5–13 with stretchability of up to 100%. Furthermore, these composite membranes are biocompatible as evident by neuronal cell attachment tests with in vitro PC12 cell lines. As follows, this newly developed implantable multifunctional membrane has considerable potential for applications in bioengineered devices such as mechano-sensitive artificial interfaces and skins.

Thylakoids, on which complete sets of photosynthetic membrane proteins are contained, behave as soft nanoparticles of a few tens nm sizes. Thus, we separated the thylakoid extracts from spinach chloroplasts and densely organized them in a film with either insulating polyethyleneimine (PEI) or conducting polyaniline (PANI) by molecularly controlled layer-by-layer (LBL) assembly. The resulting nanostructured composite films demonstrated photoelectrochemical activities with thylakoids whose stabilities were significantly improved on the charge balanced LBL multilayers compared to one on a randomly deposited film or in solution. The thylakoid LBL films continuously generated photochemical electrons for longer than 130 h with the 2,6-dichlorophenolindophenol (DCPIP) mediated photosynthetic energy conversion cycle while photoactivities of thylakoid moiety slowly decreased in the open circuit potential measurements throughout which the photosynthetic redox cycles were incomplete. As the photofunctional groups of the thylakoid films originated from a biotic system and the photofuctional thylakoids were exceptionally well preserved on the charge-balanced artificial structures, the developed thylakoid LBL film have shown inherent biocompatibility upon PC12 neural cell attachment and differentiation tests, which are essential qualities for emerging human-friendly electronic applications such as disposable electronics, artificial retina, and implantable neural interfacing meditronics as well as cell-free photosynthetic production.

The microporous layer (MPL) in proton exchange membrane fuel cells (PEMFCs) improves the fuel cell performance remarkably. However, PEMFCs suffer from local oxygen starvation at high current densities because of the accumulation of water at the cathode. This paper presents a novel water management technique that uses open furrows with serpentine patterns in the MPL. The laser ablation technique is used to carve open furrows in the MPL, and the various properties of the furrowed MPL are characterized. To examine the effects of the furrowed MPL on water management, the polarization behavior, impedance response, and potential variation under dynamic load tests are studied experimentally and theoretically for PEMFCs with three different gas diffusion layers. The results indicate that open furrows in the MPL reduce the water saturation in the catalyst layer and increase the water discharge to the gas flow channel, thereby promoting oxygen transport to the catalyst sites.

We describe the synthesis and characterization of hierarchically porous organic-inorganic hybrid silica with periodic 2-D hexagonal order and tunable location of secondary nanopores through co-condensation of tetraethylorthosilicate (TEOS) and a new type of amphiphilic organosilicate precursors. Our amphiphilic organosilicates offer unique tunability of secondary micropores by carefully controlled bond molecular structure and number of bonds between hydrophobic adamantylphenols pore-generating moieties and siloxane precursors. Small angle X-ray scattering (SAXS) and microscopy results show a good structural order of the organic-inorganic hybrid silica. In addition, 29Si CP-MAS NMR spectra confirm the successful incorporation of organosilicate precursors into a silica framework. The primary cylindrical mesopores (∼6.4 nm) were originated from the cooperative self-assembly of Pluronic P123 triblock copolymer templates while smaller meso-/micropores were derived from adamantylphenols groups. We have previously demonstrated that adam-graft SQ had an affinity for hydrophobic PO core blocks to be located close to PO segment, which resulted in small pores next to primary mesopores and the resultant increment of mesopore size as well as wrinkled silica walls. On the contrary, the secondary small pores were mainly generated within a silica network while the size of the primary mesopores unaffected with the addition of adam-bridge SQ due to its selective incorporation into a silica framework. Moreover, the organic-inorganic hybrid silica prepared with adam-bridge SQ showed higher thermal stability than that of adam-graft SQ and SBA-15 type mesoporous silica. It is attributed to more Si O Si bonds formed from the bridged structure as well as enhanced hydrogen-bonding interaction between adam-bridge SQ hybrid silica and P123 templates.

This review article focuses on the preparation and applications of layer-by-layer (LBL) assembled organic/inorganic films. As model systems we use incorporation of two multi-functional nanomaterials in the LBL: the clay nanosheets and carbon nanotubes. All the aspects of the composite design starting with the structure of the individual nano-scale building blocks and their interactions with polymer matrix, orientation of the inorganic components in the multilayer, origin of record properties, and most likely applications of the resulting materials are given. Special attention is placed on the understanding of the control parameters for key functional properties such as mechanical strength/stiffness/toughness, electrical transport, transparency, and some properties relevant for biological applications.

Layer-by-layer assembled (LBL) materials from single-wall carbon nanotubes and multiwall carbon nanotubes revealed promising mechanical properties attributed to the uniform distribution of inorganic filler in the organic polyelectrolyte matrix. In this paper, we extend the family of LBL layered nanocomposites to include another important building block i.e. vapor-grown carbon nanofibers (VGCFs). Besides the advantages of low cost, mass production, and relatively small amount of impurities, VGCFs have convenient tubular morphology. Using the LBL film deposition method free-standing polymer composite films with high loadings (>46%) of VGCFs were successfully prepared and examined by scanning electron microscopy, UV–visible spectroscopy and thermal gravimetric analysis. Combined with permeable nature of polyelectrolyte multilayers, these layered composites can be exceptionally useful for smart materials with release-on-command functionality, which requires considerable mechanical strength and thermal and/or electrical conductivity. Such applications may include biological implants, anticorrosion coatings, and thermal/electrical interface materials. Inherent versatility of LBL technology affords preparation of unique multifunctional materials by layering carbon nanofibers with other nanoscale building blocks, for instance, proteins, nanoparticles, clay sheets and others.

Noncompaction of ventricular myocardium (NVM) is a morphogenetic anomaly of ventricular myocardium that leads to the development of cardiomyopathy. It is frequently associated with other congenital cardiac malformations. A 75-year-old woman was admitted with resting dyspnea lasting for several days. Two-dimensional echocardiography demonstrated an enlarged left ventricle with global impairment of systolic function. The myocardial trabeculations, with multiple recesses, were observed at the apex and mid-ventricular segment of the left ventricle. Contrast echocardiography showed filling of the recesses with the contrast agent. Dynamic contrast magnetic resonance imaging also showed distinctive features of NVM corresponding to the echocardiographic findings. In addition, a coronary artery originating from the proximal ascending aorta was observed. Aortogram and coronary angiography confirmed that the coronary artery had an aberrant origin from the ascending aorta and right coronary artery was an anomalous origin from left anterior descending coronary artery. This case suggests that NVM can present with other life threatening cardiovascular anomalies and different imaging studies are helpful for a comprehensive diagnosis.