Ordered Mesoporous Silica Delivering siRNA as Cancer Nanotherapeutics: A Comprehensive Review

Nanosized mesoporous silica has emerged as a promising flexible platform delivering siRNA for cancer treatment. This ordered mesoporous nanosized silica provides attractive features of well-defined and tunable porosity, structure, high payload, and multiple functionalizations for targeted delivery and increasing biocompatibility over other polymeric nanocarriers. Moreover, it also overcomes the lacunae associated with traditional administration of drugs. Chemically modified porous silica matrix efficiently entraps siRNA molecules and prevents their enzymatic degradation and premature release. This Review discusses the synthesis of silica using the sol-gel approach and the advantages with different silica mesostructure. Herein, the factors affecting the synthesis of silica at nanometer scale, shape, porosity and nanoparticle surface modification are also highlighted to attain the desired nanostructured silica carriers. Additional emphasis is given to chemically modified silica delivering siRNA, where the silica nanoparticle surface was modified with different chemical moieties such as amine modified with (3-aminoropyl) triethoxysilane, polyethylenimine, chitosan, poly(ethylene glycol), and cyclodextrin polymer modification to attain high therapeutic loading, improved dispersibility and biocompatibility. Upon systemic administration, ordered mesoporous nanosized silica encounters blood cells, immune cells, and organs mainly of the reticuloendothelial system (RES). Thereby, biocompatibility and biodistribution of silica based nanocarriers are deliberated to design principles for smart and efficacious nanostructured silica-siRNA carriers and their clinical trial status. This Review further reports the future scopes and challenges for developing silica nanomaterial as a promising siRNA delivery vehicle demanding FDA approval.

Core-Shell Structure of Photopolymer-Grafted Polyurethane as a Controlled Drug Delivery Vehicle for Biomedical Application

Functionalized ultraviolet photocurable bisphenol A-glycerolate dimethacrylates with tailorable size have been synthesized as the core, which have further been grafted using the diisocyanate chain end of polyurethane (PU) as the shell to create a core-shell structure of tunable size for a controlled drug delivery vehicle. The core-shell structure has been elucidated through spectroscopic techniques like 1H NMR, FTIR, and UV-vis and their relative shape and size through TEM and AFM morphology. The greater cross-link density of the core is reflected in the higher glass transition temperature, and the improved thermal stability of the graft copolymer is proven from its thermogravimetric analyses. The flow behavior and enhanced strength of the graft copolymers have been revealed from rheological measurements. The graft copolymer exhibits sustained release of the drug, as compared to pure polyurethane and photopolymer, arising from its core-shell structure and strong interaction between the copolymer and drug, as observed through a significant shifting of absorption peaks in FTIR and UV-vis measurements. Biocompatibility has been tested for the real application of the novel graft copolymer in medical fields, as revealed from MTT assay, cell imaging, and cell adhesion studies. The efficacy of controlled release from a graft copolymer has been verified from the gradual cell killing and ∼70% killing in 3 days vs meager cell killing of ∼25% very quickly in 1 day, followed by the increased cell viability of the system treated with the pure drug. The mechanism of slow and controlled drug release from the core-shell structure has been explored. The fluorescence images support the higher cell-killing efficiency as opposed to a pure drug or a drug embedded in polyurethane. Cells seeded on 3D scaffolds have been developed by embedding a graft copolymer, and fluorescence imaging confirms the successful growth of cells within the scaffold, realizing the potential of the core-shell graft copolymer in the biomedical arena.

Poly(N-acryloylglycine-acrylamide) Hydrogel Mimics the Cellular Microenvironment and Promotes Neurite Growth with Protection from Oxidative Stress

In this work, the glycine-based acryloyl monomer is polymerized to obtain a neurogenic polymeric hydrogel for regenerative applications. The synthesized poly(N-acryloylglycine-acrylamide) [poly(NAG-b-A)] nanohydrogel exhibits high swelling (∼1500%) and is mechanically very stable, biocompatible, and proliferative in nature. The poly(NAG-b-A) nanohydrogel provides a stable 3D extracellular mimetic environment and promotes healthy neurite growth for primary cortical neurons by facilitating cellular adhesion, proliferation, actin filament stabilization, and neuronal differentiation. Furthermore, the protective role of the poly(NAG-b-A) hydrogel for the neurons in oxidative stress conditions is revealed and it is found that it is a clinically relevant material for neuronal regenerative applications, such as for promoting nerve regeneration via GSK3β inhibition. This hydrogel additionally plays an important role in modulating the biological microenvironment, either as an agonist and antagonist or as an antioxidant. Furthermore, it favors the physiological responses and eases the neurite growth efficiency. Additionally, we found out that the conversion of glycine-based acryloyl monomers into their corresponding polymer modulates the mechanical performance, mimics the cellular microenvironment, and accelerates the self-healing capability due to the responsive behavior towards reactive oxygen species (ROS). Thus, the p(NAG-b-A) hydrogel could be a potential candidate to induce neuronal regeneration since it provides a physical cue and significantly boosts neurite outgrowth and also maintains the microtubule integrity in neuronal cells.

Piezoelectric nanogenerators for self-powered wearable and implantable bioelectronic devices

One of the recent innovations in the field of personalized healthcare is the piezoelectric nanogenerators (PENGs) for various clinical applications, including self-powered sensors, drug delivery, tissue regeneration etc. Such innovations are perceived to potentially address some of the unmet clinical needs, e.g., limited life-span of implantable biomedical devices (e.g., pacemaker) and replacement related complications. To this end, the generation of green energy from biomechanical sources for wearable and implantable bioelectronic devices gained considerable attention in the scientific community. In this perspective, this article provides a comprehensive state-of-the-art review on the recent developments in the processing, applications and associated concerns of piezoelectric materials (synthetic/biological) for personalized healthcare applications. In particular, this review briefly discusses the concepts of piezoelectric energy harvesting, piezoelectric materials (ceramics, polymers, nature-inspired), and the various applications of piezoelectric nanogenerators, such as, self-powered sensors, self-powered pacemakers, deep brain stimulators etc. Important distinction has been made in terms of the potential clinical applications of PENGs, either as wearable or implantable bioelectronic devices. While discussing the potential applications as implantable devices, the biocompatibility of the several hybrid devices using large animal models is summarized. This review closes with the futuristic vision of integrating data science approaches in developmental pipeline of PENGs as well as clinical translation of the next generation PENGs. STATEMENT OF SIGNIFICANCE: Piezoelectric nanogenerators (PENGs) hold great promise for transforming personalized healthcare through self-powered sensors, drug delivery systems, and tissue regeneration. The limited battery life of implantable devices like pacemakers presents a significant challenge, leading to complications from repititive surgeries. To address such a critical issue, researchers are focusing on generating green energy from biomechanical sources to power wearable and implantable bioelectronic devices. This comprehensive review critically examines the latest advancements in synthetic and nature-inspired piezoelectric materials for PENGs in personalized healthcare. Moreover, it discusses the potential of piezoelectric materials and data science approaches to enhance the efficiency and reliability of personalized healthcare devices for clinical applications.

Evaluation of anticancer activity of Gmelina asiatica leaves, in-vitro and in-silico studies

Cervical cancer poses a major threat to women's health worldwide, constituting the fourth most prevalent cancer among the female population. High-risk variants of human papillomavirus (HPV) with its oncogenic proteins are a necessary cause of cervical cancer. Due to the resistance of cancer cells to the current treatment, there is a need for new medicines with new strategies to treat cervical cancer. Gmelina asiatica Linn. is a medicinal plant with various traditional uses and biological activities. Its anticancer potential against breast cancer and lymphoma has been demonstrated in the literature. In view of this, our study aims to investigate the anticancer activity of Gmelina asiatica leaves against cervical cancer. Various extracts of Gmelina asiatica leaves were prepared by soxhletation and maceration methods. The cytotoxic activity of the extracts was evaluated through in-vitro studies against SiHa cell line using MTT assay and fluorescence imaging. The most potent extract (GAME) phytochemical profile was analysed by UHPLC-HRMS. Further, in-silico studies were performed on its phytoconstituents against E6 oncoprotein, and the DFT studies were conducted on the active component to assess the physicochemical properties. In-vitro studies revealed that methanolic extract (GAME) showed the highest inhibition on the SiHa cell line compared to the other extracts and the control (p < 0.0001). In-silico studies indicated high affinity with stable interaction of the compound 5 (JC5ABDR) at E6 binding sites. This study revealed the importance of Gmelina asiatica plant as a potential source of anticancer molecules with a specific mode of action against cervical cancer.Communicated by Ramaswamy H. Sarma.

3D Printing of a Biocompatible Nanoink Derived from Waste Animal Bones

Direct ink writing (DIW) additive manufacturing is a versatile 3D printing technique for a broad range of materials. DIW can print a variety of materials provided that the ink is well-engineered with appropriate rheological properties. DIW could be an ideal technique in tissue engineering to repair and regenerate deformed or missing organs or tissues, for example, bone and tooth fracture that is a common problem that needs surgeon attention. A critical criterion in tissue engineering is that inserts must be compatible with their surrounding environment. Chemically produced calcium-rich materials are dominant in this application, especially for bone-related applications. These materials may be toxic leading to a rejection by the body that may need secondary surgery to repair. On the other hand, there is an abundance of biowaste building blocks that can be used for grafting with little adverse effect on the body. In this work, we report a bioderived ink made entirely of calcium derived from waste animal bones using a benign process. Calcium nanoparticles are extracted from the bones and the ink prepared by mixing with different biocompatible binders. The ink is used to print scaffolds with controlled porosity that allows better growth of cells. DIW printed parts show better mechanical properties and biocompatibility that are important for the grafting application. Degradation tests and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay study were done to examine the biocompatibility of the extracted materials. In addition, discrete element modeling and computational fluid dynamics numerical methods are used in Rocky and Ansys software programs. This work shows that biowaste materials if well-engineered can be a never-ending source of raw materials for advanced application in orthopedic grafting.

Induced Piezoelectricity in Cotton-Based Composites for Energy-Harvesting Applications

A flexible and easily processable polymer composite is developed from naturally occurring piezoelectric materials for efficient energy-harvesting applications. Tomato peel (TP)- and cotton (CTN)-based poly(vinylidene fluoride) (PVDF) composites have been prepared and the role of induced electroactive phases have been explored through structural, thermal, and morphological analyses for their applications in energy production. The mechanism of induced piezoelectricity is vividly demonstrated using electromechanical responses and characteristic changes due to induction phenomena. The CTN-based composite generates a maximum output voltage and current of 65 V and 2.1 μA, respectively, as compared to the maximum output voltage and current of 23 V and 0.7 μA in TP-based composites due to the significant induction of the piezoelectric phase in the presence of suitable electroactive cotton. The fabricated device is able to store charges in capacitors and converts the external stress through different motions of the human body to generate a considerable output, which describes the applicability of the material and justifies the potential as an efficient and sustainable biomechanical energy harvester.

3D bioprinting and its innovative approach for biomedical applications

3D bioprinting or additive manufacturing is an emerging innovative technology revolutionizing the field of biomedical applications by combining engineering, manufacturing, art, education, and medicine. This process involved incorporating the cells with biocompatible materials to design the required tissue or organ model in situ for various in vivo applications. Conventional 3D printing is involved in constructing the model without incorporating any living components, thereby limiting its use in several recent biological applications. However, this uses additional biological complexities, including material choice, cell types, and their growth and differentiation factors. This state-of-the-art technology consciously summarizes different methods used in bioprinting and their importance and setbacks. It also elaborates on the concept of bioinks and their utility. Biomedical applications such as cancer therapy, tissue engineering, bone regeneration, and wound healing involving 3D printing have gained much attention in recent years. This article aims to provide a comprehensive review of all the aspects associated with 3D bioprinting, from material selection, technology, and fabrication to applications in the biomedical fields. Attempts have been made to highlight each element in detail, along with the associated available reports from recent literature. This review focuses on providing a single platform for cancer and tissue engineering applications associated with 3D bioprinting in the biomedical field.

Fluoropolymers and Their Nanohybrids As Energy Materials: Application to Fuel Cells and Energy Harvesting

The current review article provides deep insight into the fluoropolymers and their applications in energy technology, especially in the field of energy harvesting and the development of fuel cell electrolyte polymeric membranes. Fluoropolymers have gained wide attention in the field of energy applications due to their versatile properties. The incorporation of nanofillers within the fluoropolymer to develop the nanohybrid results in an enhancement in the properties, like thermal, mechanical, gas permeation, different fuel cross-over phenomena through the membrane, hydrophilic/hydrophobic nature, ion transport, and piezo-electric properties for fabricating energy devices. The properties of nanohybrid materials/membranes are influenced by several factors, such as type of filler, their size, amount of filler, level of dispersion, surface acidity, shape, and formation of networking within the polymer matrix. Fluoropolymer-based nanohybrids have replaced several commercial materials due to their chemical inertness, better efficacy, and durability. The addition of certain electroactive fillers in the polymer matrix enhances the polar phase, which enhances the applicability of the hybrid for fuel cell and energy-harvesting applications. Poly(vinylidene fluoride) is one of the remarkable fluoropolymers in the field of energy applications such as fuel cell and piezoelectric energy harvesting. In the present review, a detailed discussion of the different kinds of nanofillers and their role in energy harvesting and fuel cell electrolyte membranes is projected.

Nanomedicine and versatile therapies for cancer treatment

The higher prevalence of cancer is related to high rates of mortality and morbidity worldwide. By virtue of the properties of matter at the nanoscale, nanomedicine is proven to be a powerful tool to develop innovative drug carriers with greater efficacies and fewer side effects than conventional therapies. In this review, different nanocarriers for controlled drug release and their routes of administration have been discussed in detail, especially for cancer treatment. Special emphasis has been given on the design of drug delivery vehicles for sustained release and specific application methods for targeted delivery to the affected areas. Different polymeric vehicles designed for the delivery of chemotherapeutics have been discussed, including graft copolymers, liposomes, hydrogels, dendrimers, micelles, and nanoparticles. Furthermore, the effect of dimensional properties on chemotherapy is vividly described. Another integral section of the review focuses on the modes of administration of nanomedicines and emerging therapies, such as photothermal, photodynamic, immunotherapy, chemodynamic, and gas therapy, for cancer treatment. The properties, therapeutic value, advantages, and limitations of these nanomedicines are highlighted, with a focus on their increased performance versus conventional molecular anticancer therapies.

Efficient Herbicide Delivery through a Conjugate Gel Formulation for the Mortality of Broad Leaf Weeds

Carfentrazone-ethyl is embedded in guar gum to prepare a polymer-herbicide conjugate gel formulation for a sustained release of the active ingredient (a.i.). The sprayable gel formulation was optimized at 0.5% (w/v) concentration. Strong interactions of the prepared composition of the polymer-herbicide conjugate system are shown through spectroscopic techniques, depicting the peak broadening of hydrophilic -OH bonds in the herbicide at 1743 cm^-1, shifting to 1730 cm^-1 in the polymer-herbicide sample. There is a broadening and shifting of the peak at 329 nm for the n → π* transition at 335 nm in the polymer-herbicide conjugate system in UV spectra. Differential scanning calorimetric measurements show a lowering of endothermic melting peaks to 242 and 303 °C in the polymer-herbicide conjugate. X-ray diffraction studies showed a sharp diffraction peak of the pure polymer at a 2θ of ∼20.3°, while broadening and shifting of the peak position to a 2θ of ∼20.8° were observed after adding the herbicide. Diffusion of the active ingredient in the polymer-herbicide conjugate resulted in much greater coverage (most of the weed leaf stomata (>95%)) than conventional spraying. The efficacy of both the polymer-herbicide formulation and herbicide at different doses in weed nurseries showed significantly higher weed mortality in Anagallis arvensis (95.4%), Chenopodium album (∼97%), and Ageratum conyzoides (93.16%) treated with the polymer-herbicide formulation @ 20 g a.i. ha^-1. Narrow SPAD readings range of A. arvensis (0.1-30.6) and that of C. album (0-5) were observed in the polymer-herbicide formulation @ 20 g a.i. ha^-1 was at par with the conventional formulation @ 30 g a.i. ha^-1. Less regeneration in a weed nursery of A. arvensis (27%), C. album (77%), and A. conyzoides (49%) treated with gel formulations @ 20 g a.i. ha^-1 was observed, which was significantly lower than those in conventional herbicides.

Correction to Poly(vinylidene fluoride-co-chlorotrifluoro ethylene) Nanohybrid Membrane for Fuel Cell

[This corrects the article DOI: 10.1021/acsomega.7b01635.].

Functionalized polyurethane composite gel electrolyte with cosensitized photoanode for higher solar cell efficiency using a passivation layer

Graphene oxide was chemically tagged with thermoplastic polyurethane, chain extended using butanediol to obtain the varying molecular weight of the polymer. Graphene-tagged polyurethane was functionalized using propane sultone to introduce the polar sulphonate groups in the main chain. The chain extension, tagging of GO and functionalization have been verified through spectroscopic techniques such as NMR, FTIR, UV and gel permeation chromatography. Thermal stability and the nature of the interaction were explored through thermal measurements to understand the effect of GO and functionalization. Electrical conduction was improved by the chemical attachment of graphene with the polymer (5.08 × 10^-7 S cm^-1), which further increases through functionalization and subsequent use of the additive (1.07 × 10^-3 S cm^-1) and make them suitable for gel electrolyte, being in the range of semiconductors. Quantum dots of CdS and CdSe were prepared using a capping agent and their characteristic properties and dimensions were worked out for their suitability as active materials in a solar cell. The optical band gap of quantum dots and HOMO/LUMO band structure of functionalized polyurethanes were measured using UV-vis and cyclic voltammetry, and thereby, constructing the overall energy diagrams for a possible combination of materials. Conducting carbon has been incorporated in the gel electrolyte to modulate the conductivity, while the ZnSe layer has been inserted as a passivation layer between the active material and the gel electrolyte. Solar cell devices were fabricated using the suitable materials, through the suitable energy diagram, and found a significantly high power conversion efficiency of 1.71%. The reason behind the improved efficiency is understood from the greater light harvesting behaviour, higher level of conductivity and blocking capacity of the various layered structures to reduce the electron-hole pair recombination.

Biocompatible Thermoresponsive N-isopropyl-N-(3-(isopropylamino)-3-oxopropyl)acrylamide - Based Random Copolymer : Synthesis and Studies of Its Composition Dependent Properties and Anticancer Drug Delivery Efficiency

A new acrylamide monomer, N-isopropyl-N-(3-(isopropylamino)-3-oxopropyl)acrylamide (M3i), consisting of both isopropyl and isopropylamidopropyl moieties, has been synthesized from isopropylamine and N-isopropylacrylamide via aza-Michael addition reaction followed by amidation with acryloyl chloride....

Correction: Nanochannel conduction in piezoelectric polymeric membrane using swift heavy ions and nanoclay

Correction for ‘Nanochannel conduction in piezoelectric polymeric membrane using swift heavy ions and nanoclay’ by Karun Kumar Jana et al., RSC Adv., 2013, 3, 6147–6159. DOI: 10.1039/C3RA23176C

Controlled DNA Delivery Using Poly(lactide) Nanoparticles and Understanding the Binding Interactions

Cationic polymer-based gene delivery vectors suffer from several limitations such as low DNA-loading capacity, poor transfection, toxicity, environmental degradations, etc. Again, very limited works are available addressing the binding interactions in detail at the atomic level explaining the loading capacity, protection ability against harsh environments, and controlled release behavior of the DNA-encapsulated vehicles. Here, a poly(l-lactide) (PLA) nanoparticle-based controlled DNA release system is proposed. The developed vehicle possesses a high DNA-loading capacity and can release the loaded DNA in a controlled manner. Spectroscopic, physicochemical, and molecular simulation techniques (AM1 and atomistic molecular dynamics) have been employed to understand the binding interactions between PLA and DNA molecules enabling high DNA loading, protection against external harsh environments, and controlled DNA release behavior. Methyl thiazolyl tetrazolium (MTT) assay experiments confirm the biocompatible nature of the vehicle. Cellular uptake efficiency and endo-lysosomal escape capabilities have been investigated against HeLA cells. This study, therefore, demonstrates the development of a promising nonviral DNA delivery vector and includes a detailed investigation of the atomic-level interaction behavior between PLA and DNA molecules.

Injectable hydrogels of newly designed brush biopolymers as sustained drug-delivery vehicle for melanoma treatment

Novel biocompatible and brush copolymers have been developed for cancer treatment using its controlled drug-release potential. Polyurethane graft on linear dextrin has been synthesized to control the hydrophilic-hydrophobic balance for regulated drug delivery. The properties of the graft copolymers have been tuned through graft density. The prepared grafts are thermally stable and mechanically strong. An injectable hydrogel has been developed by embedding the drug-loaded brush copolymers in methyl cellulose to better control the release for a prolonged period, importantly by keeping the drug release at a constant rate. Cellular studies indicate the biocompatible nature of the brush copolymers whose controlled and slow release of drug exhibit significant cytotoxic effects on cancer cells. Endocytosis of drug tagged contrast agent indicates greater transport of biologically active material inside cell as observed through cellular uptake studies. In vivo studies on melanoma mice exhibit the real efficacy of the controlled drug release from the injectable hydrogel with significant melanoma suppression without any side effects as opposed to severe toxic effects observed in conventional chemotherapy. Special application method of drug-loaded hydrogel just beneath the tumor makes this system incredibly effective through confinement. Thus, brush copolymer injectable hydrogel is a promising vehicle for control release of drug for cancer treatment in future.

Performance simulation of polymer-based nanoparticle and void dispersed photonic structures for radiative cooling

Passive radiative cooling is an emerging field and needs further development of material. Hence, the computational approach needs to establish for effective metamaterial design before fabrication. The finite difference time domain (FDTD) method is a promising numerical strategy to study electromagnetic interaction with the material. Here, we simulate using the FDTD method and report the behavior of various nanoparticles (SiO₂, TiO₂, Si₃N₄) and void dispersed polymers for the solar and thermal infrared spectrums. We propose the algorithm to simulate the surface emissive properties of various material nanostructures in both solar and thermal infrared spectrums, followed by cooling performance estimation. It is indeed found out that staggered and randomly distributed nanoparticle reflects efficiently in the solar radiation spectrum, become highly reflective for thin slab and emits efficiently in the atmospheric window (8–13 µm) over the parallel arrangement with slight variation. Higher slab thickness and concentration yield better reflectivity in the solar spectrum. SiO₂-nanopores in a polymer, Si₃N₄ and TiO₂ with/without voids in polymer efficiently achieve above 97% reflection in the solar spectrum and exhibits substrate independent radiative cooling properties. SiO₂ and polymer combination alone is unable to reflect as desired in the solar spectrum and need a highly reflective substrate like silver.

Electrochemical transformation of Prussian blue analogues into ultrathin layered double hydroxide nanosheets for water splitting

Herein, we demonstrate a template directed route for the synthesis of self-supported cobalt-iron based Prussian blue analogues (PBAs). The PBAs are electrochemically transformed into layered double hydroxides to produce excellent water oxidation and hydrogen evolution activity, while the overall water splitting is attained at a cell voltage of 1.58 V to reach 20 mA cm-2 current density.

Biocompatible fluorescent probe for detecting mitochondrial alkaline phosphatase activity in live cells

Alkaline phosphatase (ALP) is an enzyme that actively plays a significant role in the various metabolic processes by transferring a phosphate group to the protein, nucleic acid, etc. The elevated level of ALP in blood plasma is the hallmark of inflammation/cancer. The hyperactive mitochondria in cancer cells produce an excess of ATP to fulfill the high energy demand. Thus, we have developed a fluorescent probe Mito-Phos for ALP, which can detect phosphatase expression in mitochondria in live cells. The probe Mito-Phos has shown ~15-fold fluorescence intensity increments at 450 nm in the presence of 500 ng/mL of ALP. It takes about 60 min to consume the whole amount of ALP (500 ng/mL) in physiological buffer saline. It can selectively react with ALP even in the presence of other probable cellular reactive components. It is highly biocompatible and nontoxic to the live cells. It has shown ALP expression in a dose-dependent manner by providing concomitant fluorescence images in the blue-channel region. It has localized exclusively in the mitochondria in live cells. The probe Mito-Phos is highly biocompatible with the ability to assess ALP expression in mitochondria in live cells.

Fabrication of Conducting Nanochannels Using Accelerator for Fuel Cell Membrane and Removal of Radionuclides: Role of Nanoparticles

Latent tracks in pure polymer and its nanohybrid are fabricated by irradiating with swift heavy ions (SHI) (Ag⁺) having 140 MeV energy followed by selective chemical etching of the amorphous path, caused by the irradiation of SHI, to generate nanochannels of size ∼80 nm. Grafting is done within the nanochannels utilizing free radicals generated from the interaction of high-energy ions, followed by tagging of ionic species to make the nanochannels highly ion-conducting. The uniform dispersion of two-dimensional nanoparticles better controls the size and number density of the nanochannels and, thereby, converts them into an effective membrane. The nanoparticle and functionalization induce a piezoelectric β-phase in the membrane. The functionalized membrane removes the radioactive nuclide like ²⁴¹Am⁺³ (α-emitting source) efficiently (∼80% or 0.35 μg/cm²) from its solution/waste. This membrane act as a corrosion inhibitor (92% inhibition efficiency) together with its higher proton conduction (0.13 S/m) ability. The higher ion-exchange capacity, water uptake, ion conduction, and high sorption by the nanohybrid membrane are explored with respect to the extent of functionalization and control over nanochannel dimension. A membrane electrode assembly has been fabricated to construct a complete fuel cell, which exhibits superior power generation (power density of 45 mW/cm² at a current density of 298 mA/cm²) much higher than that of the standard Nafion, measured in a similar condition. Further, a piezoelectric matrix along with its anticorrosive property, high sorption characteristics, and greater power generation makes this class of material a smart membrane that can be used for many different applications.

Tunable shape memory behavior of polymer with surface modification of nanoparticles

In-situ inclusion of different nanoclays during synthesis results in different level of dispersion of nanoclays in the polymer matrix depending upon the surface modification of the nanoclay. Higher intercalation of the polymer chains within the galleries of organically modified nanoclay results better dispersion as compared to pristine nanoclay. The spectroscopic measurement shows that the extent of interaction between the nanoclay and polymer chains is higher in modified nanoclay nanocomposite which decreases the crystallinity considerably as compared to pristine clay nanocomposite. Interestingly, shape memory behavior measured at physiological temperature (37 °C) improves significantly in presence of organically modified nanoclay while it decreases in presence of unmodified nanoclay in same polyurethane matrix. Complete melting of soft segment along with restricted flipping of hard segment with temperature in presence of extensive interaction in nanocomposite with modified nanoclay helps it to achieve better shape memory behavior against flipping induced stacking of hard segment with temperature along with poor interaction decreases its shape memory behavior in nanocomposite with unmodified nanoclay. Temperature dependent nanostructure reveals the cause of variation in shape memory behavior in presence of organically modified nanoclay. Further, the cell culture studies like cell adhesion, cell viability assay and fluorescence imaging, suggest superior biomaterial of the nanocomposite with modified nanoclay as compared to other composite. Better biodegradable nature of the modified nanocomposite makes it suitable candidate for its potential biomedical applications.

Layered Double Hydroxide Nanoparticles for Efficient Gene Delivery for Cancer Treatment

The use of cationic polymer based gene delivery vectors has several limitations such as low transfection efficiency, high toxicity, and inactivation by serum. The present work provides an inorganic based nanocarrier for efficient gene delivery and a method for preparing the same through a facile coprecipitation technique. The vehicle showed high loading capacity of DNA and can release the loaded DNA in a controlled pH-responsive manner. The developed gene delivery vehicle offers remarkable protection against DNase I and also provides protection against thermal damage. This vehicle also demonstrated efficient cellular uptake performance. Transfection and expression of plasmid gene encoding GFP proteins is achieved successfully by this LDH based vehicle. More interestingly, the developed Li-Al LDH efficiently induces GFP-p53 mediated apoptosis in HeLa cells exclusively sparing the normal tissue cells like NIH-3T3. The study demonstrates the potential of the developed inorganic based nanocarrier as a promising nonviral gene vector for tumor treatment.

Nanohybrid Scaffold of Chitosan and Functionalized Graphene Oxide for Controlled Drug Delivery and Bone Regeneration

Nanohybrid scaffolds of chitosan have been designed for controlled drug delivery and bone regeneration. Sulfonated graphene oxide has been used to develop the nanohybrids. Nanohybrid scaffolds show highly hydrophilic character and greater mechanical strength as compared to pure chitosan. Nanohybrid scaffolds show an interconnected uniform porous network structure exhibiting sustained release kinetics of the antibacterial drug, tetracycline hydrochloride. Nanohybrids are found to be highly biocompatible in nature and are able to support and proliferate MG63 osteoblast cells and thereby induce bone tissue regeneration. The in-vivo bone healing study shows that the developed nanohybrid scaffolds have the potential to regenerate the bone faster without any side effects as compared to pure scaffolds. Hence, the developed nanohybrid scaffold has good potential as a controlled drug delivery vehicle and in bone tissue engineering for faster healing.

Biomaterials for Interfacing Cell Imaging and Drug Delivery: An Overview

This feature article provides an overview of different kinds of futuristic biomaterials which have the potential to be used for fluorescent imaging and drug delivery, often simultaneously. The synthesis route or preparation process, fluorescence property, release profile, biocompatibility, bioimaging, and mechanistic approaches are vividly discussed. These include bioimaging with fluorescently doped quantum dots, mesoporous silica, noble metals, metal clusters, hydrophilic/hydrophobic polymers, semiconducting polymer dots, carbon/graphene dots, dendrimers, fluorescent proteins, and other nanobiomaterials. Another section discusses the controlled and targeted drug, gene, or biologically active material delivery using various vehicles such as micelles, 2D nanomaterials, organic nanoparticles, polymeric nanohybrids, and chemically modified polymers. In the last section, we discuss biomaterials, which can deliver biologically active molecules, and imaging the cell/tissue.

Targeted therapy in chronic diseases using nanomaterial-based drug delivery vehicles

The application of nanomedicines is increasing rapidly with the promise of targeted and efficient drug delivery. Nanomedicines address the shortcomings of conventional therapy, as evidenced by several preclinical and clinical investigations indicating site-specific drug delivery, reduced side effects, and better treatment outcome. The development of suitable and biocompatible drug delivery vehicles is a prerequisite that has been successfully achieved by using simple and functionalized liposomes, nanoparticles, hydrogels, micelles, dendrimers, and mesoporous particles. A variety of drug delivery vehicles have been established for the targeted and controlled delivery of therapeutic agents in a wide range of chronic diseases, such as diabetes, cancer, atherosclerosis, myocardial ischemia, asthma, pulmonary tuberculosis, Parkinson's disease, and Alzheimer's disease. After successful outcomes in preclinical and clinical trials, many of these drugs have been marketed for human use, such as Abraxane®, Caelyx®, Mepact®, Myocet®, Emend®, and Rapamune®. Apart from drugs/compounds, novel therapeutic agents, such as peptides, nucleic acids (DNA and RNA), and genes have also shown potential to be used as nanomedicines for the treatment of several chronic ailments. However, a large number of extensive clinical trials are still needed to ensure the short-term and long-term effects of nanomedicines in humans. This review discusses the advantages of various drug delivery vehicles for better understanding of their utility in terms of current medical needs. Furthermore, the application of a wide range of nanomedicines is also described in the context of major chronic diseases.

Retracted Article: A bio-based piezoelectric nanogenerator for mechanical energy harvesting using nanohybrid of poly(vinylidene fluoride)

A bio-based piezoelectric egg shell membrane (ESM) is used for energy harvesting applications in the form of two and three-component nanohybrids. A bio-waste piezo-filler in a piezoelectric polymer matrix was designed through an induced β-phase nucleation in the matrix using an organically modified two-dimensional nanoclay. Structural alteration (α to β-phase) in the presence of the nanoparticles was also manifested by morphological changes over spherulite to a needle-like morphology; thus, these nanohybrid materials are suitable for energy harvesting applications. ESM-based nanogenerators were fabricated with local ordering of piezo phases, as revealed via atomic force microscopy, leading to the generation of mostly electroactive phases in the whole nanohybrid. The voltage outputs from the optimized device were measured to be ∼56 and 144 V in single and multiple stacks (five), respectively, with corresponding power densities of 55 μW cm^-2 and 100 μW cm^-2. The efficiency of the device was verified using a variety of body movements, e.g. bending, twisting, walking, and foot tapping, causing mechanical energy dissipation, which eventually transformed into energy storage. The underlying mechanism of high conversion of energy is explained by the synergistically induced piezo-phase in the polymer matrix together with the floppy piezo-filler. The mechanical stability, durability and repeated energy conversion of the hybrid device make it a robust nanogenerator. The biocompatibility of the nanogenerator was verified through cellular studies, demonstrating its appropriate use in powering biomedical devices/implants.

Health benefits of resveratrol: Evidence from clinical studies

Resveratrol is a polyphenolic nutraceutical that exhibits pleiotropic activities in human subjects. The efficacy, safety, and pharmacokinetics of resveratrol have been documented in over 244 clinical trials, with an additional 27 clinical trials currently ongoing. Resveretrol is reported to potentially improve the therapeutic outcome in patients suffering from diabetes mellitus, obesity, colorectal cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Alzheimer's disease, stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The polyphenol is reported to be safe at doses up to 5 g/d, when used either alone or as a combination therapy. The molecular basis for the pleiotropic activities of resveratrol are based on its ability to modulate multiple cell signaling molecules such as cytokines, caspases, matrix metalloproteinases, Wnt, nuclear factor-κB, Notch, 5'-AMP-activated protein kinase, intercellular adhesion molecule, vascular cell adhesion molecule, sirtuin type 1, peroxisome proliferator-activated receptor-γ coactivator 1α, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, Ras association domain family 1α, pAkt, vascular endothelial growth factor, cyclooxygenase 2, nuclear factor erythroid 2 like 2, and Kelch-like ECH-associated protein 1. Although the clinical utility of resveratrol is well documented, the rapid metabolism and poor bioavailability have limited its therapeutic use. In this regard, the recently produced micronized resveratrol formulation called SRT501, shows promise. This review discusses the currently available clinical data on resveratrol in the prevention, management, and treatment of various diseases and disorders. Based on the current evidence, the potential utility of this molecule in the clinic is discussed.