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Novel nanoemulsion-based drug delivery systems (DDS) have been proposed as alternative and effective approach for the delivery of various types of poorly water-soluble drugs in the last decade. This nanoformulation strategy significantly improves the cell uptake and bioavailability of numerous hydrophobic drugs by increasing their solubility and dissolution rate, maintaining drug concentration within the therapeutic range by controlling the drug release rate, and reducing systemic side effects by targeting to specific disease site, thus offering a better patient compliance. To date, cavitation technology has emerged to be an energy-efficient and promising technique to generate such nanoscale emulsions encapsulating a variety of highly potent pharmaceutical agents that are water-insoluble. The micro-turbulent implosions of cavitation bubbles tear-off primary giant oily emulsion droplets to nano-scale, spontaneously leading to the formation of highly uniform drug contained nanodroplets. A substantial body of recent literatures in the field of nanoemulsions suggests that cavitation is a facile, cost-reducing yet safer generation tool, remarkably highlighting its industrial commercial viability in the development of designing novel nanocarriers or enhancing the properties of existing pharmaceutical products. In this review, the fundamentals of nanoemulsion and the principles involved in their formation are presented. The underlying mechanisms in the generation of pharmaceutical nanoemulsion under acoustic field as well as the advantages of using cavitation compared to the conventional techniques are also highlighted. This review focuses on recent nanoemulsion-based DDS development and how cavitation through ultrasound and hydrodynamic means is useful to generate the pharmaceutical grade nanoemulsions including the complex double or submicron multiple emulsions.

Development of nanomaterials is continuously on the rise owing to their variety of technological applications and thus gets increased attention not only in the academic research but also on an industrial scale. Nanomaterials behave in a different way compared to their counterpart and showing markedly different properties which may be physical, chemical, biological, electronic, etc. Common techniques that are employed in the development of nanomaterials are high energy ball milling, hydrothermal synthesis, co-precipitation, microemulsion, sol-gel processing, etc. Due to the inherent disadvantages existing with these conventional techniques newer processing methods are always have great consideration. In this connection, cavitation induced by ultrasound exhibits many advantages. Not only the nanomaterials are obtained using this technique, even the nanoformulations such as nanoemulsions could be generated using this technology.

Much effort is currently being devoted in Nanotechnology owing to its diverse range of technological applications. Nanotechnology deals with the design, characterization, production and application of structures, devices and systems by controlling their size and shape at nanometre scale. It focuses on manipulating the most basic components of all matter (atoms and molecules) with great precision and exploiting the novel properties or phenomena observed at that length scale as compared to their bulk-scale counterparts. Thus size effects become predominant at the nano scale. Most of the observed effects at this nano scale could be explained by surface and quantum confinement phenomena. It is an emerging interdisciplinary technology and promises significant advances in various technological applications. Nanotechnology is the new industrial revolution as it has the potential to revolutionise various sectors of the society. Still the potential of this technology has not been fully exploited as many questions still remain to be answered. Notwithstanding these advantages, it is a challenge to the government and industries as yet there are no specific regulations for assessing the toxicity or environmental impact of nanoparticles.

In the present investigation, the operating efficiency of a bench-top air-driven microfluidizer has been compared to that of a bench-top high power ultrasound horn in the production of pharmaceutical grade nanoemulsions using aspirin as a model drug. The influence of important process variables as well as the pre-homogenization and drug loading on the resultant mean droplet diameter and size distribution of emulsion droplets was studied in an oil-in-water nanoemulsion incorporated with a model drug aspirin. Results obtained show that both the emulsification methods were capable of producing very fine nanoemulsions containing aspirin with the minimum droplet size ranging from 150 to 170 nm. In case of using the microfluidizer, it has been observed that the size of the emulsion droplets obtained was almost independent of the applied microfluidization pressure (200-600 bar) and the number of passes (up to 10 passes) while the pre-homogenization and drug loading had a marginal effect in increasing the droplet size. Whereas, in the case of ultrasound emulsification, the droplet size was generally decreased with an increase in sonication amplitude (50-70%) and period of sonication but the resultant emulsion was found to be dependent on the pre-homogenization and drug loading. The STEM microscopic observations illustrated that the optimized formulations obtained using ultrasound cavitation technique are comparable to microfluidized emulsions. These comparative results demonstrated that ultrasound cavitation is a relatively energy-efficient yet promising method of pharmaceutical nanoemulsions as compared to microfluidizer although the means used to generate the nanoemulsions are different.

The present study investigated the anti-inflammatory and analgesic activities of novel aspirin oil-in-water (O/W) nanoemulsion and water-in-oil-in-water (W/O/W) nano multiple emulsion formulations generated using ultrasound cavitation techniques. The anti-inflammatory activities of nanoemulsion and nano multiple emulsion were determined using the λ-carrageenan-induced paw edema model. The analgesic activities of both nanoformulations were determined using acetic acid-induced writhing response and hot plate assay. For comparison, the effect of pretreatment with blank nanoemulsion and reference aspirin suspension were also studied for their anti-inflammatory and antinociceptive activities. The results showed that oral administration of nanoemulsion and nano multiple emulsion containing aspirin (60 mg/kg) significantly reduced paw edema induced by λ-carrageenan injection. Both nanoformulations decreased the number of abdominal constriction in acetic acid-induced writhing model. Pretreatment with nanoformulations led to a significant increase in reaction time in hot plate assay. Nanoemulsion demonstrated an enhanced anti-inflammatory and analgesic effects compared to reference suspension while nano multiple emulsion exhibited a mild inhibitory effects in the three experimental animal model tests. The results obtained for nano multiple emulsion were relatively lower than reference. However, administration of blank nanoemulsion did not alter the nociceptive response significantly though it showed slight anti-inflammatory effect. These experimental studies suggest that nanoemulsion and nano multiple emulsion produced a pronounced anti-inflammatory and analgesic effects in rats and may be candidates as new nanocarriers for pharmacological NSAIDs in the treatment of inflammatory disorders and alleviating pains.

We report on a simple and novel sonochemical method for the preparation of polyaniline (PANI), as well as its composite, with Au nanoparticles. This technique utilizes ultrasound radiation as an energy source to facilitate the reaction by reducing the reaction time, as well as significantly increasing the yield. The tremendous increase in the reaction rates is explained on the basis of the intensive bubble collapse conditions, which rapidly generate the oxidative radicals necessary for polymerization.

Zirconia hollow spheres were prepared using yeast cells as templates. Zirconium butoxide (ZNB) was used as a precursor and treated with triethanolamine (TEA) in order to obtain a basic aqueous zirconium hydroxide solution. Thus obtained basic zirconium hydroxide solution was then nucleated heterogeneously using yeast cells as templates. The results of this investigation show that the formed zirconia hollow spheres either keep the shape of the yeast cells or otherwise have a wrinkled shell. The shell of hollow spheres heated at 973K for 3 hours was from 0.1 to 0.25μm in thickness and consisted of the nano crystals.

Fine particles of rutile TiO2 supporting nanosized particles of Pt were prepared by a simultaneous in situ sonochemical reduction and deposition method using a standing wave sonochemical reactor (SWSR). The mean diameter of sonochemically obtained Pt particles are of 2 nm. Following this sonochemical technique, rutile TiO2 was also deposited with different weight percentages of Pt. Catalytic function of the prepared composite catalysts were tested by the oxidation of CO to CO(2). From the catalytic activity results, it has been found out that the catalysts prepared by the sonochemical method exhibited higher catalytic activity for CO oxidation, probably attributed to the higher Pt particle distribution achieved under sonication. Transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), and diffuse reflectance spectroscopy (DRS) were employed to characterize the resulting material.

The pace of research into the synthesis of nanometer‐sized particles has increased remarkably over recent years, driven by the technological potential of these structures for applications in electronics, photonics and biotechnology as well as a fundamental scientific interest. Nanotechnology research has thus become one of the most active frontier areas in recent years. Due to the potential, the techniques to fabricate these nanomaterials are also increasing. Out of a range of techniques, ultrasonic cavitation is one of the techniques which has numerous merits over conventional techniques. Although conceptually simple, fabrication by this approach is more challenging. In this paper, the developments related to the use of ultrasonic cavitation for the fabrication of nanomaterials and biomaterials have been described.

The sustained extensive research on graphene and its derivatives in the last decade portrayed its significance in the field of material science and carved its own niche in nanotechnology. Starting from the simple pencil, the role of graphene now extends to a lifesaver through innovations in nanomedicine specifically the early detection of abnormalities and efficient treatments. Graphene has the potential to satisfy the nanotechnological concepts of personalized and regenerative medicine for a disease-free future. The functionalization techniques ameliorate graphene for improved solubility, stability, loading capacity, etc. which makes it an ideal nanosystem for theranostic applications such as biosensing, drug delivery, gene therapy, bioimaging, phototherapy and hybrid theranostics. In addition, due to its electrically tunable surface chemistry, maximal surface-to-volume ratio, easy functionalization capacity and mechanical robustness, graphene gained enormous attention in tissue engineering specifically in cardiac, nerve, bone, skin and stem cells. This review focusses on the recent developments in graphene-based nanotheranostics and tissue engineering, which reveals the hidden potential of modern medical notions in efficiently handling the variety of abnormalities. Moreover, it raises the necessity of successful therapeutic systems to transfer from bench-to-bedside through clinical trials to enhance the current treatment scenario. Refereed/Peer-reviewed