Application of self-assembly in polypeptide drugs: a review / 生物工程学报

Self-assembly refers to the spontaneous process where basic units such as molecules and nanostructured materials form a stable and compact structure. Peptides can self-assemble by non-covalent driving forces to form various morphologies such as nanofibers, nano layered structures, and micelles. Peptide self-assembly technology has become a hot research topic in recent years due to the advantages of definite amino acid sequences, easy synthesis and design of peptides. It has been shown that the self-assembly design of certain peptide drugs or the use of self-assembled peptide materials as carriers for drug delivery can solve the problems such as short half-life, poor water solubility and poor penetration due to physiological barrier. This review summarizes the formation mechanism of self-assembled peptides, self-assembly morphology, influencing factors, self-assembly design methods and major applications in biomedical field, providing a reference for the efficient use of peptides.

Role of biomimetic nanomaterials made from glioma cell- derived extracellular vesicles in targeted delivery of STAT3-siRNA / 中南大学学报(医学版)

OBJECTIVES@#Glioma is the most common primary intracranial tumor and there is still no ideal treatment at present. Gene therapy, as one of the new methods for treating glioma, has attracted attention in recent years. But its application in treating glioma is very limited due to lack of effective delivery vectors. This study aims to investigate the feasibility of biomimetic nanomaterials made from glioma cells-derived extracellular vesicles (EV) for targeted delivery of signal transducers and activators of transcription 3 (STAT3)-small interfering RNA (siRNA) in treating glioma.@*METHODS@#First, U251 glioma cells-derived extracellular vessel (EVU251) was extracted by ultra-centrifugal method. Nanoparticle tracking analysis was used to characterize the particle size distribution, the transmission electron microscope was used to analyze the morphology, and Western blotting was used to verify the expression of srface characteristic protein. The homing ability was verified by cell uptake assay after labeling EVU251 with membrane dye kit PKH67; the EVU251 contents were removed by a low permeability method and then EVMU251 was prepared through a microporous membrane. Finally, the biomimetic nanomaterials EVMU251@STAT3-siRNA were prepared by loading STAT3-SiRNA with electro-dyeing method. The real-time quantitative PCR was used to quantify the successful encapsulation of siRNA, and the encapsulation and drug loading rate was calculated; then Cy5-labeled siRNA was used to evaluate the ability of biomimetic nanomaterials (EVMU251@CY5-siRNA) to target U251 cells. Lysosomal escape ability of the biomimetic nanomaterial was evaluated by lysosomal dye lyso-tracker green. At last, the ability of EVMU251@STAT3-siRNA to knock down STAT3 gene and selective killing of U251 cells was detected by cell experiments in vitro.@*RESULTS@#The size of EVU251 ranged from 50 nm to 200 nm with a natural disc shape. The expression of extracellular vesicle marker proteins could be detected on the membrane of EVU251. The cell uptake assay demonstrated that it had homing ability to target U251 cells. After EVU251 was prepared as EVMU251@STAT3-siRNA, the particle size was (177.9±5.0) nm, the siRNA loading rate was (33.5±2.2)% and the drug loading rate was (3.24±0.21)%. The biomimetic nanomaterial EVMU251@STAT3-siRNA still had the ability to target U251 cells and successfully deliver siRNA to the cytoplasm without lysosomal degradation. The EVMU251@STAT3-siRNA can effectively knock down the expression of STAT3 gene and produce selective killing ability in U251 cells.@*CONCLUSIONS@#The biomimetic nanomaterials EVMU251@STAT3-siRNA made from glioma U251 cells-derived extracellular vesicles can knock down STAT3 gene of U251 cells and produce selective killing effect, which can provide a new idea for the treatment of glioma.

Preparation and catalytic properties of catalase-inorganic hybrid nanoflowers / 生物工程学报

Catalase is widely used in the food, medical, and textile industries. It possesses exceptional properties including high catalytic efficiency, high specificity, and environmental friendliness. Free catalase cannot be recycled and reused in industry, resulting in a costly industrial biotransformation process if catalase is used as a core ingredient. Developing a simple, mild, cost-effective, and environmentally friendly approach to immobilize catalase is anticipated to improve its utilization efficiency and enzymatic performance. In this study, the catalase KatA derived from Bacillus subtilis 168 was expressed in Escherichia coli. Following separation and purification, the purified enzyme was prepared as an immobilized enzyme in the form of enzyme-inorganic hybrid nanoflowers, and the enzymatic properties were investigated. The results indicated that the purified KatA was obtained through a three-step procedure that included ethanol precipitation, DEAE anion exchange chromatography, and hydrophobic chromatography. Then, by optimizing the process parameters, a novel KatA/Ca3(PO4)2 hybrid nanoflower was developed. The optimum reaction temperature of the free KatA was determined to be 35 ℃, the optimum reaction temperature of KatA/Ca3(PO4)2 hybrid nanoflowers was 30-35 ℃, and the optimum reaction pH of both was 11.0. The free KatA and KatA/Ca3(PO4)2 hybrid nanoflowers exhibited excellent stability at pH 4.0-11.0 and 25-50 ℃. The KatA/Ca3(PO4)2 hybrid nanoflowers demonstrated increased storage stability than that of the free KatA, maintaining 82% of the original enzymatic activity after 14 d of storage at 4 ℃, whereas the free KatA has only 50% of the original enzymatic activity. In addition, after 5 catalytic reactions, the nanoflower still maintained 55% of its initial enzymatic activity, indicating that it has good operational stability. The Km of the free KatA to the substrate hydrogen peroxide was (8.80±0.42) mmol/L, and the kcat/Km was (13 151.53± 299.19) L/(mmol·s). The Km of the KatA/Ca3(PO4)2 hybrid nanoflowers was (32.75±2.96) mmol/L, and the kcat/Km was (4 550.67±107.51) L/(mmol·s). Compared to the free KatA, the affinity of KatA/Ca3(PO4)2 hybrid nanoflowers to the substrate hydrogen peroxide was decreased, and the catalytic efficiency was also decreased. In summary, this study developed KatA/Ca3(PO4)2 hybrid nanoflowers using Ca2+ as a self-assembly inducer, which enhanced the enzymatic properties and will facilitate the environmentally friendly preparation and widespread application of immobilized catalase.

Challenges in the use of nanostructures as carriers of nucleic acids in clinical practice

ABSTRACT The delivery of nucleic acids to cells is considered a crucial step for the success of genetic modifications aimed at therapeutic purposes or production of genetically modified animals. In this context, nanotechnology is one of the most promising fields of science, with the potential to solve several existing problems. Nanostructures have desirable characteristics to be used as carriers, such as nanometric size, large surface area, cell internalization capacity, prolonged and controlled release, among others. Genetically modified animals can contribute to the production of biopharmaceuticals, through the expression of high-associated-value molecules. The production of these animals, also known as biofactories, further enhances Brazilian agribusiness, since it allows adding value to the final product, and favors the integration between the agricultural market and the pharmaceutical sector. However, there is a growing concern about the safety and possible harmful effects of nanostructures, since data on the safe use of these materials are still insufficient. The objective of this review was to address aspects of the use of nanostructures, mainly carbon nanotubes as nucleic acid carriers, aiming at the production of genetically modified animals, with the certainty that progress in this field of knowledge depends on more information on the mechanisms of interaction between nanostructures, cells and embryos, as well as on its toxicity.

Determination of Shear Bond Strength of Nanocomposite to Porcelain and Metal Alloy

Abstract Objective: To compare porcelain and metal repair done with both nanocomposite and conventional composite. Material and Methods: A total of 30 cylinders were fabricated from Porcelain (I), Porcelain fused to metal (II), and metal (III) substrate each. Control group (A) was bonded with conventional micro-hybrid composite and experimental group (B) was bonded with nanocomposite in a 2 mm thickness. All specimens were thermocycled and stored in distilled water at 37 °C for 7 days. A universal testing machine was used to measure the Shear bond strength (SBS). The difference between bond strengths of the groups was compared using an independent t-test. Results: In all three groups, the SBS was higher in the experimental group as compared to the control group. The use of nanocomposite of metal alloy presented maximum shear bond strength, followed by samples of porcelain fused to metal and finally porcelain, showing the lowest values of SBS. Conclusion: Porcelain and alloys bonded with nanocomposite exhibit enhanced adhesiveness as well as aesthetic and mechanical properties. This subsequently would translate into providing higher clinical serviceability and durability and hence a cost-effective and accessible repair option for human welfare (AU).

Synthesis of silver nanoparticles using Lactobacillus bulgaricus and assessment of their antibacterial potential / Síntese de nanopartículas de prata usando Lactobacillus bulgaricus e avaliação de seu potencial antibacteriano

Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in "De Man, Rogasa, and Sharp" broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.

Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo "De Man, Rogasa e Sharp" para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.

Challenges of nanotechnology in cosmetic permeation with caffeine / Desafios da nanotecnologia na permeação cosmética com cafeína

The evolution of beauty market and personal care is constant in Brazil as well in the rest of the world. Technological advances have brought up nanotechnology to the cosmetological field, employing active principles at atoms enveloped by vesicles, in order to take the active principle precisely to the target tissue to optimize the results achieved because of the considerable ease to cross skin barriers. Manufacturing of nanotechnology cosmetics is confronted with low absorption capacity. One of the many active principle found in cosmetic industry is caffeine, a pseudoalkaloid from the xanthine group used as a stimulant with the mechanism of the lipolytic action. This active is widely used in a esthetics and cosmetics field in treatments involving dysfunctions such as localized fat and fibroedema geloid. To work out perfectly, the principle active need to interact and create a set of factors that includes lipolysis intensification. The caffeine encapsulation in gel-based nanocosmetics has the purpose of taking this active up to the adipocyte, the target cell, for mentioned dysfunctions treatment. Thus, we aim to present a review of how has been, the use of caffeine in the production of cosmetics.

A evolução do mercado de beleza e cuidados pessoais é constante no Brasil e no resto do mundo. Os avanços tecnológicos trouxeram a nanotecnologia para o campo cosmetológico, empregando princípios ativos em átomos envolvidos por vesículas, a fim de levar o princípio ativo precisamente ao tecido alvo para otimizar os resultados alcançados devido à considerável facilidade de atravessar barreiras cutâneas. A fabricação de cosméticos nanotecnológicos é confrontada com baixa capacidade de absorção. Um dos muitos princípios ativos encontrados na indústria cosmética é a cafeína, um pseudoalocalóide do grupo xantina usado como estimulante no mecanismo da ação lipolítica. Este ativo é amplamente utilizado no campo da estética e dos cosméticos em tratamentos que envolvem disfunções, como gordura localizada e fibroedema gelóide. Para funcionar perfeitamente, o princípio ativo precisa interagir e criar um conjunto de fatores que inclui a intensificação da lipólise. O encapsulamento de cafeína em nanocosméticos à base de gel tem o objetivo de levar esse ativo até o adipócito, a célula alvo, para o tratamento de disfunções mencionado. Assim, objetivamos apresentar uma revisão de como tem sido o uso de cafeína na produção de cosméticos.

Research progress about photothermal nanomaterials with targeted antibacterial properties and their applications in wound healing / 生物医学工程学杂志

With the development of photothermal nanomaterials, photothermal therapy based on near-infrared light excitation shows great potential for the bacterial infected wound treatment. At the same time, in order to improve the photothermal antibacterial effect of wound infection and reduce the damage of high temperature and heat to healthy tissue, the targeted bacteria strategy has been gradually applied in wound photothermal therapy. In this paper, several commonly used photothermal nanomaterials as well as their targeted bacterial strategies were introduced, and then their applications in photothermal antibacterial therapy, especially in bacterial infected wounds were described. Besides, the challenges of targeted photothermal antibacterial therapy in the wound healing application were analyzed, and the development of photothermal materials with targeted antibacterial property has prospected in order to provide a new idea for wound photothermal therapy.

Formulation optimization of emodin nanostructured lipid carriers by Box-Behnken response surface method and in vitro quality evaluation / 中国中药杂志

Emodin nanostructured lipid carriers(ED-NLC) were prepared and their quality was evaluated in vitro. Based on the results of single-factor experiments, the ED-NLC formulation was optimized by Box-Behnken response surface method with the dosages of emodin, isopropyl myristate and poloxamer 188 as factors and the nanoparticle size, encapsulation efficiency and drug loading as evaluation indexes. Then the evaluation was performed on the morphology, size and in vitro release of the nanoparticles prepared by emulsification-ultrasonic dispersion method in line with the optimal formulation, i.e., 3.27 mg emodin, 148.68 mg isopropyl myristate and 173.48 mg poloxamer 188. Under a transmission electron microscope(TEM), ED-NLC were spherical and their particle size distribution was uniform. The particle size of ED-NLC was(97.02±1.55) nm, the polymer dispersion index 0.21±0.01, the zeta potential(-38.96±0.65) mV, the encapsulation efficiency 90.41%±0.56% and the drug loading 1.55%±0.01%. The results of differential scanning calorimeter(DSC) indicated that emodin may be encapsulated into the nanostructured lipid carriers in molecular or amorphous form. In vitro drug release had obvious characteristics of slow release, which accorded with the first-order drug release equation. The fitting model of Box-Behnken response surface methodology was proved accurate and reliable. The optimal formulation-based ED-NLC featured concentrated particle size distribution and high encapsulation efficiency, which laid a foundation for the follow-up study of ED-NLC in vivo.

Peptide-based bioactivated in vivo assembly nanomaterials and its biomedical applications: a review / 生物工程学报

Based on the self-assembly process occurring in the human body all the time, self-assembled nanomaterials were designed by the researchers. The self-assembled nanomaterials have controllability, biocompatibility and functional advantages in vivo. The self-assembled nanomaterials constructed in situ under a physiological environment display various biological characteristics which can be used for imaging, therapy, and broad clinical applications. In situ self-assembled nanomaterials can boost drug function, reduce toxic and side effects, prolong imaging time and enlarge signal-to-noise ratio. By using pathological conditions to trigger specific responses in vivo, well-ordered nanoaggregates can be spontaneously formed by multiple weak bonding interactions. The assembly shows higher accumulation and longer retention in situ. Endogenous triggers for in situ assembly, such as enzymes, pH, reactive oxygen species and ligand receptor interaction, can be used to transform the materials into a variety of controllable nanostructures including nanoparticles, nanofibers and gels through bioactivated in vivo assembly (BIVA) strategies. BIVA strategies can be applied for treatment, imaging or participate in the physiological activities of cells at the lesion site. This review summarized and prospected the design of self-assembled peptide materials based on BIVA technology and their biomedical applications. The nanostructures of the self-assembly enable some beneficial biological effects, such as assembly induced retention (AIR) effect, enhanced targeting effect, multivalent bond effect, and membrane disturbance. Thus, the BIVA nanotechnology is promising for efficient drug delivery, enhancement of targeting and treatment, as well as optimization of the biological distribution of drugs.

Direct Synthesis of Bienzyme-like Carbide-derived Carbons via Mild Electrochemical Oxidation of Ti 3AlC 2 MAX / 生物医学与环境科学（英文）

Objective@#To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes.@*Methods@#Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques.@*Results@#CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively.@*Conclusion@#The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.

Effect of graphene oxide on the function of erythrocytes / 生物工程学报

The biocompatibility of nanomaterials has attracted much attention. Graphene oxide (GO) is a nanomaterial widely used in biomedicine, but its toxicity can not be ignored. In this study, the effect of GO on the blood system (the hemolysis rate, the fragility of erythrocyte, and acetylcholinesterase activity) was systematically investigated. The results showed that the hemolysis rate of erythrocytes was lower than 8% when the GO concentration was below 100 μg/mL (P5 μm (LGO) increased the activity of acetylcholinesterase by 42.67% (P<0.05). Then molecular dynamics simulation was used to study how GO interacted with acetylcholinesterase and increased its activity. The results showed that GO was attached to the cell membrane, thus may provide an electronegative environment that helps the hydrolysate to detach from the active sites more quickly so as to enhance the activity of acetylcholinesterase.

Research progress on the application of framework nucleic acid in bone regeneration / 华西口腔医学杂志

Framework nucleic acid (FNA) is a set of DNA nanostructures characterized by the framework morphology. It can design rational DNA sequences and follow the principle of complementary base pairing to construct FNA. The recent discovery of FNA constructed by DNA nanotechnology has great application potential in the field of bone regene-ration. It plays a positive role in the osteogenic differentiation of stem cells, bone regeneration, vascular regeneration, neuromodulation, immune regulation, and drug delivery. Here, we reviewed the current study findings on FNA in the field of bone regeneration.

Bio-based molecules for biosynthesis of nano-metallic materials / 生物工程学报

Nano-metallic materials are playing an important role in the application of medicine, catalysis, antibacterial and anti-toxin due to their obvious advantages, including nanocrystalline strengthening effect, high photo-absorptivity, high surface energy and single magnetic region performance. In recent years, with the increasing consumption of global petrochemical resources and the aggravation of environmental pollution, nanomaterials based on bio-based molecules have aroused great concern. Bio-based molecules refer to small molecules and macromolecules directly or indirectly derived from biomass. They usually have good biocompatibility, low toxicity, degradability, wide source and low price. Besides, most bio-based molecules have unique physical, chemical properties and physiological activity, such as optical activity, acid/alkali amphoteric property, hydrophilic property and easy coordination with metal ions. Thus, the corresponding nano-materials based on bio-based molecules also have unique functions, such as anti-inflammatory, anti-cancer, anti-oxidation, antiviral fall blood sugar and blood fat etc. In this paper, we give a comprehensive overview of the preparation and application of nano-metallic materials based on bio-based molecules in recent years.

Simple synthesis of photoluminescent carbon dots from a marine polysaccharide found in shark cartilage

BACKGROUND: For more than a decade, water-soluble, eco-friendly, biocompatible, and low-toxicity fluorescent nanomaterials have received considerable attention for their numerous in vivo and in vitro applications in biomedical imaging, disease diagnostics, and environmental monitoring. Owing to their tunable photoluminescence properties, carbon-based luminescent nanomaterials have shown great potential in bioimaging, photocatalysis, and biosensing among other applications. RESULTS: Marine environments provide excellent resources for the fabrication of these nanomaterials, because many marine organisms contain interesting trigger organic compounds that can be used as precursors. Herein, we synthesize multi-color emissive carbon dots (CDs) with an intrinsic photoluminescence quantum yield of 20.46%. These nanostructures were achieved through the one-step hydrothermal treatment of marine polysaccharide chondroitin sulfate, obtained from shark cartilage, in aqueous solution. CONCLUSIONS: We successfully demonstrate the low toxicity of our marine resource-derived CDs in zebrafish, and provide an initial assessment of their possible use as a bioimaging agent. Notably, the newly synthesized CDs localize in the intestines of zebrafish larvae, thereby indicating their biocompatibility and potential use as in vivo dyes.

Research Progress on Electrochemical Biosensors for Breast Cancer Detection Based on Nanomaterials / 中国医疗器械杂志

Breast cancer is one of the most serious diseases threatening women's life and health in the world, and the mortality rate is the second in the world. With the progress of nanotechnology and the advantages of nanomaterials in the field of electrochemistry and biosensor, various nanomaterials have been applied in electrochemical biosensors. This makes the electrochemical nano-biosensor in the field of rapid detection of breast cancer has been widely concerned and studied. This paper introduces the important components of electrochemical nano-biosensor for breast cancer detection and the research progress of each component in breast cancer detection, as well as the performance of electrochemical nano biosensor in breast cancer detection and the prospect of its application.

Synthesis of folate modified chitosan-based nanomicelles and its anti-tumor activity / 浙江大学学报·医学版

OBJECTIVE@#To design and synthesize folate-modified pH-responsive chitosan-based nanomicelles and investigate the anti-tumor activity of the drug-loaded micelles.@*METHODS@#CHI-DMA was obtained by reductive amination reaction of aldehyde-based chitosan and hydrophilic amine compounds, and CHI-DMA-LA was obtained by condensation reaction with lauric acid; FA-CHI-DMA-LA was obtained after modification with folic acid (FA). The drug-loaded nanomicelles FA-CHI-DMA-LA/DOX were assembled by solvent change method. The physicochemical properties of polymers were characterized by hydrogen nuclear magnetic resonance and transmission electron microscope. The particle size and surface potential were determined by dynamic light scattering method. Folic acid access rate, doxorubicin (DOX) loading rate and entrapped efficiency were measured by UV-vis spectrophotometer. The drug release properties of DOX-loaded micelles were monitored by fluorescence spectrophotometer at different pHs (7.4, 6.5, 5.0). The cytotoxicity against human oral cancer KB cells was detected by MTT assay. Fluorescence microscope and flow cytometry were applied to investigate the phagocytosis of DOX-loaded micelles on KB cells.@*RESULTS@#FA-CHI-DMA-LA was synthesized. The particle sizes of FA-CHI-DMA-LA-1 and FA-CHI-DMA-LA-2 micelles which used for the subsequent experiments were (73±14) nm and (106±15) nm, zeta potential were (15.59±1.98) mV and (21.20±2.35) mV, respectively. The drug loading rates of drug-loaded micelles FA-CHI-DMA-LA-1/DOX and FA-CHI-DMA-LA-2/DOX are (4.08±1.12)%and (4.12±0.44)%, respectively. drug release is pH-responsive, with cumulative release of DOX up to 37%and 36%at pH 5.0, which is about 1.5 times higher than that of pH 7.4. For FA-CHI-DMA-LA micelles with 1.25 to 125 μg/mL concentration, the survival rate of KB cells is more than 70%after incubation for 24 hours. The cell uptake of FA-CHI-DMA-LA/DOX micelles was enhanced compared to CHI-DMA-LA/DOX, and the cell uptake was higher in incubation without FA medium than that with FA. Compared with free DOX or CHI-DMA-LA/DOX, FA-CHI-DMA-LA/DOX nanomicelles showed higher cyctoxicity to KB cells, especially the FA-CHI-DMA-LA-2/DOX nanomicelles, the cell survival rate was about 17% after incubation for 24 hours.@*CONCLUSIONS@#FA-modified chitosan-based nanomicelle with good biocompatibility was successfully prepared, which exhibits tumor microenvironmental pH responsive drug release and tumor targeting.

Effect of ginsenoside Rg_3 nanostructured lipid carrier modified by pullulan on promoting absorption and its anti-tumor evaluation in vitro / 中国中药杂志

Ginsenoside Rg_3 is widely used in clinical practice as an anti-tumor adjuvant drug, but its application is limited due to its poor oral absorption. In this study, we intended to construct a ginsenoside Rg_3 nanostructured lipid carrier modified by the pullulan(PUL-Rg_3-NLC) to improve the adhesion properties of ginsenoside Rg_3, promote the drug uptake and improve the anti-tumor efficacy. PUL-Rg_3-NLC was characterized by morphology, particle size and Zeta potential. In vivo adhesion characteristics were evaluated by oral gavage tests, and the results were verified from multiple perspectives in combination with in vitro uptake behavior and in vitro pharmacodynamics. The results showed that PUL-Rg_3-NLC, with a particle size of(102±1.89) nm, was characterized by gastric adhesion and could be retained in gastric tissues for a long time, and its uptake by BGC-823 cells was promoted mainly through the pathway mediated by the caveolin-mediated endocytosis. In vitro MTT, cell apoptosis, wound-healing assay and invasion assay all showed some anti-tumor effects. Therefore, PUL-Rg_3-NLC can significantly promote the adhesion of Rg_3 in the stomach, promote the uptake of drugs by gastric cancer cells, and improve the anti-tumor effect. This study can provide some reference for the adjuvant treatment of gastric cancer.

An efficient method of Yarrowia lipolytica immobilization using oil- and emulsion-modified bacterial cellulose carriers

Background: Yarrowia lipolytica is a nonconventional, dimorphic yeast with multiple biotechnological applications. Considering the size of Y. lipolytica cells and a plethora of its morphological forms (spherical cells or hyphae and pseudohyphae), it is highly difficult to select a suitable carrier for this useful microorganism. Bacterial cellulose (BC) is currently considered one of the most promising immobilization carriers. In the current study, the usefulness of oil- and emulsion-modified BCs as a carrier for Y. lipolytica immobilization was investigated. Static and agitated cultures were conducted in media supplemented with oil or emulsion to improve carrier porosity. Results: It was found that the application of oil- and emulsion-modified BCs correlated with significantly higher efficiency of Y. lipolytica immobilization and hence higher yield than the yield achieved with an unmodified carrier. Increased efficiency of immobilization correlated with BC porosity-related parameters, which, in turn, depended on the size of oil droplets introduced into the culture medium. Moreover, changes in porosity-related parameters caused by the addition of oil or emulsion to the medium were observed when the cultures were conducted only under static conditions and not under agitated conditions. Conclusion: The application of oil- and emulsion-modified BCs as carriers significantly increased the efficiency of Y. lipolytica immobilization as compared to unmodified BC. The addition of oil or emulsion to the culture medium can be a simple but effective method to modify the porosity of BC-based carriers.

Understanding the Internet of Nano Things: overview, trends, and challenges

ABSTRACT Over the years, technological advancements have led to rapid growth of smart environments (offices, homes, cities, etc.). The increase of intelligent environments suggests the interconnectivity of applications and the use of the Internet. For this reason, arise what is known as the Internet of Things (IoT). The expansion of the IoT concept gives access to the Internet of Nano Things (IoNT). A new communication networks paradigm based on nanotechnology and IoT, in other words, a paradigm with the capacity to interconnect nano-scale devices through existing networks. This new paradigm so-called IoNT is presented to the world as an option for various fields of application. Therefore, new challenges and research opportunities have arisen. Consequently, this work aims to investigate state of the art and analyze trends for the use of IoNT, its application and future challenges in different fields of social interest, because IoNT is presented as an option for research with the capacities needed to get involved in many fields of social welfare. It is concluded that technologies prevail current IoNT literature, applications are focused on health care, and there is no international standardization regarding privacy, security or architecture of nano-networks.

RESUMEN A través de los años, los avances tecnológicos han llevado a un rápido crecimiento de entornos inteligentes (oficinas, hogares, ciudades, etc.). El aumento de entornos inteligentes sugiere la interconectividad de las aplicaciones y el uso de la Internet. Por esta razón, surge lo que se conoce como Internet de las cosas (IoT, por sus siglas en inglés). La ampliación del concepto IoT brinda acceso a la Internet de las nano cosas (IoNT, por sus siglas en inglés), un nuevo paradigma de redes de comunicación basado en nanotecnología y IoT, en otras palabras, un paradigma con la capacidad de interconectar dispositivos a nano escala a través de redes existentes. Este nuevo paradigma denominado IoNT se presenta al mundo como una opción para diversos campos de aplicación. Por lo tanto, surgen nuevos desafíos y oportunidades de investigación. En consecuencia, este trabajo tiene como objetivo investigar el estado del arte y analizar las tendencias para el uso de IoNT, su aplicación y los desafíos futuros en diferentes campos de interés social, debido a que IoNT se presenta como una opción para la investigación con las capacidades necesarias para involucrarse en muchos campos del bienestar social. Se concluye que la literatura actual de IoNT está prevalecida por las tecnologías, las aplicaciones se enfocan en el cuidado de la salud y no se dispone de una estandarización internacional en cuanto a la privacidad, seguridad o la arquitectura de las nano redes.