Deep Learning Model for Cosmetic Gel Classification Based on a Short-Time Fourier Transform and Spectrogram.

Cosmetics and topical medications, such as gels, foams, creams, and lotions, are viscoelastic substances that are applied to the skin or mucous membranes. The human perception of these materials is complex and involves multiple sensory modalities. Traditional panel-based sensory evaluations have limitations due to individual differences in sensory receptors and factors such as age, race, and gender. Therefore, this study proposes a deep-learning-based method for systematically analyzing and effectively identifying the physical properties of cosmetic gels. Time-series friction signals generated by rubbing the gels were measured. These signals were preprocessed through short-time Fourier transform (STFT) and continuous wavelet transform (CWT), respectively, and the frequency factors that change over time were distinguished and analyzed. The deep learning model employed a ResNet-based convolution neural network (CNN) structure with optimization achieved through a learning rate scheduler. The optimized STFT-based 2D CNN model outperforms the CWT-based 2D and 1D CNN models. The optimized STFT-based 2D CNN model also demonstrated robustness and reliability through k-fold cross-validation. This study suggests the potential for an innovative approach to replace traditional expert panel evaluations and objectively assess the user experience of cosmetics.

Non pharmacological high-intensity ultrasound treatment of human dermal fibroblasts to accelerate wound healing.

Inspired by the effectiveness of low-intensity ultrasound on tissue regeneration, we investigated the potential effect of short-term high-intensity ultrasound treatment for acceleration of wound healing in an in vitro wound model and dermal equivalent, both comprising human dermal fibroblasts. Short-term ultrasound of various amplitudes significantly increased the proliferation and migration of fibroblasts and subsequently increased the production of the extracellular matrix components fibronectin and collagen type I, both of which are important for wound healing and are secreted by fibroblasts. In addition, ultrasound treatment increased the contraction of a fibroblast-embedded three-dimensional collagen matrix, and the effect was synergistically increased in the presence of TGF-ß. RNA-sequencing and bioinformatics analyses revealed changes in gene expression and p38 and ERK1/2 MAPK pathway activation in the ultrasound-stimulated fibroblasts. Our findings suggest that ultrasound as a mechanical stimulus can activate human dermal fibroblasts. Therefore, the activation of fibroblasts using ultrasound may improve the healing of various types of wounds and increase skin regeneration.

Acoustically responsive polydopamine nanodroplets: A novel theranostic agent.

Ultrasound-induced cavitation has been used as a tool of enhancing extravasation and tissue penetration of anticancer agents in tumours. Initiating cavitation in tissue however, requires high acoustic intensities that are neither safe nor easy to achieve with current clinical systems. The use of cavitation nuclei can however lower the acoustic intensities required to initiate cavitation and the resulting bio-effects in situ. Microbubbles, solid gas-trapping nanoparticles, and phase shift nanodroplets are some examples in a growing list of proposed cavitation nuclei. Besides the ability to lower the cavitation threshold, stability, long circulation times, biocompatibility and biodegradability, are some of the desirable characteristics that a clinically applicable cavitation agent should possess. In this study, we present a novel formulation of ultrasound-triggered phase transition sub-micrometer sized nanodroplets (~400 nm) stabilised with a biocompatible polymer, polydopamine (PDA). PDA offers some important benefits: (1) facile fabrication, as dopamine monomers are directly polymerised on the nanodroplets, (2) high polymer biocompatibility, and (3) ease of functionalisation with other molecules such as drugs or targeting species. We demonstrate that the acoustic intensities required to initiate inertial cavitation can all be achieved with existing clinical ultrasound systems. Cell viability and haemolysis studies show that nanodroplets are biocompatible. Our results demonstrate the great potential of PDA nanodroplets as an acoustically active nanodevice, which is highly valuable for biomedical applications including drug delivery and treatment monitoring.

Paclitaxel-induced formation of 3D nanocrystal superlattices within injectable protein-based hybrid nanoparticles.

Self-assembly of monodisperse superparamagnetic iron oxide nanocrystals into a close-packed, three-dimensional (3D) superlattice is designed within cross-linked protein-based nanoparticles composed of human serum albumin and polyethylene glycol. The prepared nanoparticles are very stable in serum and exhibit a high T2 relaxivity as well as anti-cancer activity, indicating the practical benefits of ordering nanocrystals.

A versatile method for the preparation of particle-loaded microbubbles for multimodality imaging and targeted drug delivery.

Microbubbles are currently in clinical use as ultrasound contrast agents and under active investigation as mediators of ultrasound therapy. To improve the theranostic potential of microbubbles, nanoparticles can be attached to the bubble shell for imaging, targeting and/or enhancement of acoustic response. Existing methods for fabricating particle-loaded bubbles, however, require the use of polymers, oil layers or chemical reactions for particle incorporation; embed/attach the particles that can reduce echogenicity; impair biocompatibility; and/or involve multiple processing steps. Here, we describe a simple method to embed nanoparticles in a phospholipid-coated microbubble formulation that overcomes these limitations. Magnetic nanoparticles are used to demonstrate the method with a range of different microbubble formulations. The size distribution and yield of microbubbles are shown to be unaffected by the addition of the particles. We further show that the microbubbles can be retained against flow using a permanent magnet, can be visualised by both ultrasound and magnetic resonance imaging (MRI) and can be used to transfect SH-SY5Y cells with fluorescent small interfering RNA under the application of a magnetic field and ultrasound field.

Amphiphilic siRNA Conjugates for Co-Delivery of Nucleic Acids and Hydrophobic Drugs.

Combination therapy of nucleic acids and chemical drugs for cancer treatment is a promising strategy to enhance the therapeutic efficacy by simultaneously regulating multiple troublesome pathways. In this study, we report on polyethylene glycol-siRNA-polycaprolactone (PEG-siRNA-PCL) micelles that encapsulate hydrophobic drugs for efficient co-delivery of siRNA and drugs to cancer cells. Amphiphilic PEG-siRNA-PCL copolymers were synthesized by annealing antisense siRNA-PCL conjugates with sense siRNA-PEG conjugates. After paclitaxel encapsulation, PEG-siRNA-PCL micelles containing antiapoptotic Bcl-2-specific siRNA were stabilized with linear polyethylenimine via electrostatic interactions. Stabilized PEG-siRNA-PCL micelles showed superior anticancer effects, assessed by caspase-3 activity analysis, apoptotic cell staining, and a cytotoxicity test, to those of paclitaxel-free PEG-siRNA-PCL micelles and unmodified siRNAs. The strong anticancer activity of paclitaxel-incorporated siRNA micelles can be attributed to the synergistic effect of Bcl-2 siRNA and paclitaxel. This work provides an efficient co-delivery platform for combination anticancer therapy with siRNA and chemotherapy.

Laser-driven resonance of dye-doped oil-coated microbubbles: Experimental study.

Photoacoustic (PA) imaging offers several attractive features as a biomedical imaging modality, including excellent spatial resolution and functional information such as tissue oxygenation. A key limitation, however, is the contrast to noise ratio that can be obtained from tissue depths greater than 1-2 mm. Microbubbles coated with an optically absorbing shell have been proposed as a possible contrast agent for PA imaging, offering greater signal amplification and improved biocompatibility compared to metallic nanoparticles. A theoretical description of the dynamics of a coated microbubble subject to laser irradiation has been developed previously. The aim of this study was to test the predictions of the model. Two different types of oil-coated microbubbles were fabricated and then exposed to both pulsed and continuous wave (CW) laser irradiation. Their response was characterized using ultra high-speed imaging. Although there was considerable variability across the population, good agreement was found between the experimental results and theoretical predictions in terms of the frequency and amplitude of microbubble oscillation following pulsed excitation. Under CW irradiation, highly nonlinear behavior was observed which may be of considerable interest for developing different PA imaging techniques with greatly improved contrast enhancement.

Ultrasound-Enhanced siRNA Delivery Using Magnetic Nanoparticle-Loaded Chitosan-Deoxycholic Acid Nanodroplets.

Small interfering RNA (siRNA) has significant therapeutic potential but its clinical translation has been severely inhibited by a lack of effective delivery strategies. Previous work has demonstrated that perfluorocarbon nanodroplets loaded with magnetic nanoparticles can facilitate the intracellular delivery of a conventional chemotherapeutic drug. The aim of this study is to determine whether a similar agent can provide a means of delivering siRNA, enabling efficient transfection without degradation of the molecule. Chitosan-deoxycholic acid nanoparticles containing perfluoropentane and iron oxide (d 0 = 7.5 ± 0.35 nm) with a mean hydrodynamic diameter of 257.6 ± 10.9 nm are produced. siRNA (AllStars Hs cell death siRNA) is electrostatically bound to the particle surface and delivery to lung cancer cells and breast cancer cells is investigated with and without ultrasound exposure (500 kHz, 1 MPa peak-to-peak focal pressure, 40 cycles per burst, 1 kHz pulse repetition frequency, 10 s duration). The results show that siRNA functionality is not impaired by the treatment protocol and that the nanodroplets are able to successfully promote siRNA uptake, leading to significant apoptosis (52.4%) 72 h after ultrasound treatment.

Facile and cost-effective production of microscale PDMS architectures using a combined micromilling-replica moulding (µMi-REM) technique.

We describe a cost-effective and simple method to fabricate PDMS-based microfluidic devices by combining micromilling with replica moulding technology. It relies on the following steps: (i) microchannels are milled in a block of acrylic; (ii) low-cost epoxy adhesive resin is poured over the milled acrylic block and allowed to cure; (iii) the solidified resin layer is peeled off the acrylic block and used as a mould for transferring the microchannel architecture onto a PDMS layer; finally (iv) the PDMS layer is plasma bonded to a glass surface. With this method, microscale architectures can be fabricated without the need for advanced technological equipment or laborious and time-consuming intermediate procedures. In this manuscript, we describe and validate the microfabrication procedure, and we illustrate its applicability to emulsion and microbubble production.

Protein-quantum dot nanohybrids for bioanalytical applications.

Quantum dots (QDs) coupled with biomolecules play an important role as optically and chemically stable bioimaging agents for various applications. These inorganic-biological hybrid conjugates have been demonstrated as powerful fluorescence tools for sensing, diagnostics, and labeling. This review focuses on protein-QD nanohybrids for different types of bioanalytical applications. There are various strategies to modify the surface properties of QDs to produce protein-QD nanohybrids that are stable in biological fluids. We expect that multifunctional protein-QD nanohybrids can be used as a powerful optical probe for various biological applications. WIREs Nanomed Nanobiotechnol 2016, 8:178-190. doi: 10.1002/wnan.1345 For further resources related to this article, please visit the WIREs website.

Nanoparticle-Loaded Protein-Polymer Nanodroplets for Improved Stability and Conversion Efficiency in Ultrasound Imaging and Drug Delivery.

A new formulation of volatile nanodroplets stabilized by a protein and polymer coating and loaded with magnetic nanoparticles is developed. The droplets show enhanced stability and phase conversion efficiency upon ultrasound exposure compared with existing formulations. Magnetic targeting, encapsulation, and release of an anticancer drug are demonstrated in vitro with a 40% improvement in cytotoxicity compared with free drug.

Biologically and Acoustically Compatible Chamber for Studying Ultrasound-Mediated Delivery of Therapeutic Compounds.

Ultrasound (US), in combination with microbubbles, has been found to be a potential alternative to viral therapies for transfecting biological cells. The translation of this technique to the clinical environment, however, requires robust and systematic optimization of the acoustic parameters needed to achieve a desired therapeutic effect. Currently, a variety of different devices have been developed to transfect cells in vitro, resulting in a lack of standardized experimental conditions and difficulty in comparing results from different laboratories. To overcome this limitation, we propose an easy-to-fabricate and cost-effective device for application in US-mediated delivery of therapeutic compounds. It comprises a commercially available cell culture dish coupled with a silicon-based "lid" developed in-house that enables the device to be immersed in a water bath for US exposure. Described here are the design of the device, characterization of the sound field and fluid dynamics inside the chamber and an example protocol for a therapeutic delivery experiment.

Low-density lipoprotein-mimicking nanoparticles for tumor-targeted theranostic applications.

This study introduces multifunctional lipid nanoparticles (LNPs), mimicking the structure and compositions of low-density lipoproteins, for the tumor-targeted co-delivery of anti-cancer drugs and superparamagnetic nanocrystals. Paclitaxel (4.7 wt%) and iron oxide nanocrystals (6.8 wt%, 11 nm in diameter) are co-encapsulated within folate-functionalized LNPs, which contain a cluster of nanocrystals with an overall diameter of about 170 nm and a zeta potential of about -40 mV. The folate-functionalized LNPs enable the targeted detection of MCF-7, human breast adenocarcinoma expressing folate receptors, in T2 -weighted magnetic resonance images as well as the efficient intracellular delivery of paclitaxel. Paclitaxel-free LNPs show no significant cytotoxicity up to 0.2 mg mL(-1) , indicating the excellent biocompatibility of the LNPs for intracellular drug delivery applications. The targeted anti-tumor activities of the LNPs in a mouse tumor model suggest that the low-density lipoprotein-mimetic LNPs can be an effective theranostic platform with excellent biocompatibility for the tumor-targeted co-delivery of various anti-cancer agents.

Microfluidic system for high throughput characterisation of echogenic particles.

Echogenic particles, such as microbubbles and volatile liquid micro/nano droplets, have shown considerable potential in a variety of clinical diagnostic and therapeutic applications. The accurate prediction of their response to ultrasound excitation is however extremely challenging, and this has hindered the optimisation of techniques such as quantitative ultrasound imaging and targeted drug delivery. Existing characterisation techniques, such as ultra-high speed microscopy provide important insights, but suffer from a number of limitations; most significantly difficulty in obtaining large data sets suitable for statistical analysis and the need to physically constrain the particles, thereby altering their dynamics. Here a microfluidic system is presented that overcomes these challenges to enable the measurement of single echogenic particle response to ultrasound excitation. A co-axial flow focusing device is used to direct a continuous stream of unconstrained particles through the combined focal region of an ultrasound transducer and a laser. Both the optical and acoustic scatter from individual particles are then simultaneously recorded. Calibration of the device and example results for different types of echogenic particle are presented, demonstrating a high throughput of up to 20 particles per second and the ability to resolve changes in particle radius down to 0.1 µm with an uncertainty of less than 3%.

Serum-stable quantum dot-protein hybrid nanocapsules for optical bio-imaging.

We introduce shell cross-linked protein/quantum dot (QD) hybrid nanocapsules as a serum-stable systemic delivery nanocarrier for tumor-targeted in vivo bio-imaging applications. Highly luminescent, heavy-metal-free Cu0.3InS2/ZnS (CIS/ZnS) core-shell QDs are synthesized and mixed with amine-reactive six-armed poly(ethylene glycol) (PEG) in dichloromethane. Emulsification in an aqueous solution containing human serum albumin (HSA) results in shell cross-linked nanocapsules incorporating CIS/ZnS QDs, exhibiting high luminescence and excellent dispersion stability in a serum-containing medium. Folic acid is introduced as a tumor-targeting ligand. The feasibility of tumor-targeted in vivo bio-imaging is demonstrated by measuring the fluorescence intensity of several major organs and tumor tissue after an intravenous tail vein injection of the nanocapsules into nude mice. The cytotoxicity of the QD-loaded HSA-PEG nanocapsules is also examined in several types of cells. Our results show that the cellular uptake of the QDs is critical for cytotoxicity. Moreover, a significantly lower level of cell death is observed in the CIS/ZnS QDs compared to nanocapsules loaded with cadmium-based QDs. This study suggests that the systemic tumor targeting of heavy-metal-free QDs using shell cross-linked HSA-PEG hybrid nanocapsules is a promising route for in vivo tumor diagnosis with reduced non-specific toxicity.

Optically traceable solid lipid nanoparticles loaded with siRNA and paclitaxel for synergistic chemotherapy with in situ imaging.

Here, we report quantum dot-incorporating solid lipid nanoparticles (SLNs) for anticancer theranostics with synergistic therapeutic effects of paclitaxel-siRNA combination. The natural components of a low-density lipoprotein (LDL) are reconstituted to produce LDL-mimetic SLNs having a stable core/shell nanostructure incorporating quantum dots and paclitaxel within the lipid shell while anionic siRNA molecules are electrostatically complexed with the outer surface of SLNs. The produced SLN/siRNA complexes efficiently deliver both of paclitaxel and Bcl-2 targeted siRNA into human lung carcinoma cells and exhibit synergistic anticancer activities by triggering caspase-mediated apoptosis as determined by median effect plot analysis. Moreover, the strong fluorescence from quantum dots within SLNs enables in situ visualization of intracellular translocation of SLNs into cancer cells. Our study suggests that LDL-mimetic SLNs can be utilized as a multifunctional and optically traceable nanocarrier for efficient anticancer theranostics.

Prolonged gene silencing by siRNA/chitosan-g-deoxycholic acid polyplexes loaded within biodegradable polymer nanoparticles.

Recently, small interfering RNA (siRNA) has received much attention for therapeutic applications; however, low transfection efficiency and intrinsic instability limit effective gene silencing. Here we show a new approach based on the incorporation of siRNA/polyelectrolyte complexes into biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles to stabilize siRNA within a hydrophobic solid matrix for prolonged gene silencing. To solubilize siRNA in organic media, chitosan oligosaccharides grafted with deoxycholic acids are synthesized and complexed with siRNA, generating a self-assembled polyelectrolyte complex of 123.9 ± 56.8 nm in diameter. The complex is mixed with PLGA solution and emulsified in water to prepare siRNA-loaded PLGA nanoparticles having a diameter of about 230 nm. The excellent structural stability of the prepared nanoparticles leads to efficient cellular uptake followed by effective gene silencing even in the presence of serum proteins. These results suggest that the encapsulation of siRNA into biodegradable polymer matrix can be an effective means of improving the structural stability of siRNA for prolonged therapeutic efficacy.

Intracellular delivery of paclitaxel using oil-free, shell cross-linked HSA--multi-armed PEG nanocapsules.

Various approaches to increase the solubility of water-insoluble anti-cancer drugs in aqueous formulations have been undertaken with the aim of treating solid tumors through intravenous drug administration. Nanoscale drug carriers are particularly attractive for cancer therapy because of their passive targeting effect to enhance the therapeutic efficacy of drugs. Here we introduce an oil-free, shell cross-linked nanocapsule as an efficient intracellular delivery system for paclitaxel. The nanocapsules are prepared by emulsifying amine-reactive six-arm-branched polyethylene glycol (PEG) in dichloromethane into aqueous solution of human serum albumin (HSA), followed by cross-linking at the organic/aqueous interface. Paclitaxel is successfully incorporated into the HSA/PEG nanocapsules having a spherical shape with an average diameter of about 280 nm. In several types of cells, the surface modification of nanocapsules with a cell-penetrating peptide, Hph1, greatly facilitates cellular uptake and apoptosis-inducing effects of paclitaxel. Furthermore, the targeted anti-tumor activities of the paclitaxel-loaded nanocapsules in a mouse tumor model suggest that the shell cross-linked nanocapsules are very promising oil-free nanoscale delivery vehicles for water-insoluble anti-cancer agents.