Rod-shaped Nanoparticles Research Articles

Investigation into the Antibacterial Mechanism of Biogenic Tellurium Nanoparticles and Precursor Tellurite.

Antibacterial tellurium nanoparticles have the advantages of high activity and biocompatibility. Microbial synthesis of Te nanoparticles is not only a green technology but builds new ecological relationships in diverse environments. However, the antibacterial mechanism of Te nanoparticles is largely unclear. In this study, we report the bacterial synthesis of rod-shaped Te nanoparticles (BioTe) with high antibacterial activity against Escherichia coli. Morphology and permeability examination indicates that membrane damage is the primary reason for the antibacterial activity of BioTe, rather than ROS production and DNA damage. Moreover, a comparison of transcriptome and relative phenotypes reveals the difference in antibacterial mechanisms between BioTe and tellurite. Based on our evidence, we propose an antibacterial mode of rod-shaped BioTe, in which positively charged BioTe interact with the cell membrane through electrostatic attraction and then penetrate the membrane by using their sharp ends. In contrast, tellurite toxicity might be involved in sulfur metabolism.

Biosynthesis and characterization of iron oxide nanoparticles from Mentha spicata and screening its combating potential against Phytophthora infestans.

Plant pathogens cause serious diseases to agricultural crops which lead to food insecurity in the world. To combat plant pathogens, various strategies have been developed including the use of agrochemicals. The overuse of these chemicals is now leading to the pesticide-resistant capability of pathogens. To overcome this problem, modern nanobiotechnology offers the production of alternative nano drugs. In this study, we used Mentha spicata for the synthesis of iron oxide nanoparticles using the green synthesis method. The synthesis of Fe2O3 NPs was confirmed through various characterizations. UV–Vis analysis detected a characteristic absorbance at the spectral range of 272 nm. The SEM micrographic analysis at various magnifications displayed circular or rod-shaped nanoparticles with a size ranging from 21 to 82 nm. The elemental EDX characterization showed intense peaks with a weight percent of 57, 34.93, and 8.07 for Fe, O, and, Cl respectively. TGA analysis showed that weight loss at 44–182, 500, and 660°C with no further modification indicates the thermal stability of iron oxide nanoparticles. FTIR spectrum of uncalined detects various bands at 3331, 1625, and 1,437 cm−1 for the hydroxyl group. After calcination two bands at 527 and 434 cm−1 were observed for Fe-O. The antimicrobial in vitro study showed maximum growth inhibition of Phytophthora infestans by the concentration of 100 μg ml−1 of Fe2O3-PE and Fe2O3 NPs. Therefore, this study resulted that bio-stable iron oxide nanoparticles can be used as alternative antimicrobial agents.

Synthesis and application of ZnO rod-shaped nanoparticles for the optimal operation of the plate heat exchanger

ZnO nanoparticles with tunable morphology exhibit attractive behaviors in transport phenomena, which make them valuable for thermal applications. The present study focuses on the synthesis and application of ZnO nanoparticles with two different shapes for the preparation of the working heat transfer nanofluid. First, the rod-shaped and spherical-shaped nanoparticles were synthesized by simple chemical methods and then ultrasonically dispersed in pure water to prepare a set of stable nanofluids with concentrations between 0.2% and 1% of nanoparticles. The nanofluid samples were analyzed thermo-physically to obtain the optimal nanoparticles volume fraction for presenting the best thermal properties. In the following, a brazed plate heat exchanger was examined to evaluate the heat transfer characteristics of the selected nanofluids as a coolant fluid at flow rates between 1 and 3.5 l/min. The experimental results showed that the lowest Prandtl number appeared at the volume fraction of 0.4%. This concentration was considered the operating basis of the heat exchanger. ZnO nanoparticles had the considerable effect on the thermal characteristics of water as a working fluid. The maximum growth in the heat transfer rate was found for the nanofluid with the rod-shaped nanoparticles at the lowest flow rate (1 l/min), which were 29.2% more than pure water and 7.5% higher than the nanofluid with spherical-shaped nanoparticles. Additionally, due to the exponential increase in the pumping power, there was a flow rate range (less than 2 l/min) in which the energetic performance of the nanofluids was higher than water.

Experimental study on synergistic enhancement of thermal performance of a closed two-phase thermosyphon by a TiO2 nanofluid doped with Al2O3

The heat transfer performance of two-phase closed thermosyphon solar collectors (TPCTs) can be improved by adding nanoparticles to the conventional working fluid, but it is necessary to ensure good rheological properties while improving the heat transfer performance. Therefore, spherical (TiO2) nanoparticles with good rheological properties and rod-shaped (Al2O3) nanoparticles with high thermal conductivity were mixed and applied to the TPCT. First, the effects of individual factors such as the concentration of nanoparticles and the operating parameters on the thermal performance of the TPCT were investigated and a regression analysis was performed. Then, the joint effect of inclination angle and filling ratio on the thermal performance of TPCT was further investigated by orthogonal experiment. The results show that doping TiO2 with Al2O3 can further improve the thermal performance of TPCT. For the volume concentration of 0.6% of nanoparticles, filling ratio of 50% and inclination angle of 80°, the best heat transfer performance of TPCT was achieved. Compared with the deionized water (DW), the thermal resistance of the single (TiO2–H2O) and hybrid (Al2O3+TiO2–H2O) nanofluid TPCT is reduced by 10.7% and 13.4%, the thermal efficiency is increased by 11.0% and 13.7%, and the equivalent heat transfer coefficient is increased by 16.2% and 18.7%, respectively.

Zinc oxide nanoparticles: Chemical and green synthesis, characterization, and comparative evaluation of their effects on caprine testis in vitro.

The present research was designed to investigate the potential effects of zinc oxide nanoparticles synthesized by both chemical and green method in caprine testis. In this study, rod-shaped zinc oxide nanoparticles (ZnONPs) with diameter less than 100 nm were prepared by chemical and green method using polyvinyl pyrrolidone (PVP) and Ocimum sanctum leaf extract as stabilizing agents respectively. X-ray diffraction, Fourier transform infrared spectroscopy, LCMS, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and EDX were utilized to characterize the synthesized zinc oxide nanoparticles. The histomorphological alterations of both chemically synthesized and biosynthesized zinc oxide nanoparticles were evaluated after administration of two doses (10 µg/ml and 20 µg/ml) for exposure duration of 4 h and 8 h. Chemically synthesized zinc oxide nanoparticles induced significant damage in testicular cells in dose and time-dependent manner. The Histomorphological changes included desquamation in germinal epithelium, pyknosis in germ cells, increased vacuolization, loss of mature spermatozoa from lumen and wide interstitial space between seminiferous tubules. Protective effects of biosynthesized zinc oxide nanoparticles were recorded at lower dose whereas some alterations were observed when treated with 20 µg/ml for 4 h and 8 h culture duration. The results confirmed that phytochemicals present in leaf extract of O. sanctum mitigated the zinc oxide nanoparticles induced toxicity, proving biosynthesized nanoparticles are better than chemically synthesized nanoparticles.

Azadirachta indica leaf extract mediated biosynthesized rod-shaped zinc oxide nanoparticles for in vitro lung cancer treatment

In this work, ZnO nanoparticles (NPs – L5 and L10) are biosynthesized using 5 mL and 10 mL leaf extract of Azadirachta indica, respectively. As-prepared L5/L10 NPs revealed hexagonal wurtzite structure while their surface is attached with phytochemicals coating. FESEM micrographs confirmed 50 – 120 and 30 – 70 nm rod-shaped L5/L10 ZnO nanoparticles. DLS study showed hydrodynamic sizes 580.41/356.2 nm and zeta potential values of −47.17/−51.70 mV for L5/L10, respectively indicating their good colloidal stability. The anticancer activity of L5/L10 NPs is evaluated via MTT assay which confirmed that the cell viability of A549 cells is significantly reduced depending on the dosage of L5/L10 NPs. Moreover, IC50 values are obtained as 125.64 and 115.63 μg/mL for L5 and L10, respectively. Furthermore, flow cytometry reveals 88 % and 89.3 % arrest of the G1 phase of the cell cycle due to the anticancer effect of L5 and L10 NPs, respectively.

Simple model of the electrophoretic migration of spherical and rod-shaped Au nanoparticles in gels with varied mesh sizes

Spherical and rod-shaped Au nanoparticles with various particle sizes (< 70 nm) were synthesized via the seeded growth method and utilized in gel electrophoresis under varied gel mesh sizes to investigate their migration velocities. Due to the strong effect of the gel, which consists of a three-dimensional mesh network with adjustable mesh sizes via the agarose concentration, the migration of the nanoparticles was retarded by steric and/or hydrodynamic interactions leading to e.g. friction as well as attraction and finally to decreased migration velocities. It was observed that the migration velocity of rod-shaped nanoparticles was less diminished in gels with smaller mesh sizes compared to spherical nanoparticles with one similar dimension (length of rod corresponded to diameter of sphere). These experimental data were used to validate modeled migration velocities using Henry’s equation. However, this retardation is not sufficiently addressed by Henry’s equation and therefore, a migration factor was included in the model, setting the mesh size in ratio to the particle size as well as the particle morphology. Despite its simplicity, this new model allows a more accurate prediction of the migration velocity during the gel electrophoresis under various conditions.

(Invited) Synthesis and Optical Properties of Rod-Shaped Graphene Nanoparticles

The scientific community has given much interest to graphene in recent years because of its good mechanical, thermal and electrical properties. Nonetheless, applications in optics and optoelectronics can be limited due to the absence of a bandgap. In order to engineer a bandgap, we can reduce the size of graphene into graphene quantum dots (GQDs). GQDs synthesis is primarily described via top-down methods (lithography, hydrothermal and electrochemical approaches).[1] Though effective, these methods do not allow accurate control of the size, shape and edges of the GQDs. On the other hand, bottom-up graphene materials have developed exponentially for the last decade with the synthesis of highly controlled graphene nanoribbon structures and moderately soluble graphene quantum dots.[2,3] Our group demonstrated that bottom-up GQDs could act as single-photon emitters exhibiting high brightness and stability.[4]In order to investigate the structure-property relationship, we designed a series of rod-shaped graphene nanoparticles that differ only by their length, keeping the same morphology, symmetry and edge states (see figure). These nanoparticles are fully soluble, which facilitate their purification and individualization in solution and give rise to well-defined absorption spectra. Here we report on the synthesis of these GQDs, and we will present results on advanced characterization of their optical properties.[5][1] Yang, J.-S., Martinez, D. A. & Chiang, W.-H. Synthesis, Characterization and Applications of Graphene Quantum Dots in Recent Trends in Nanomaterials: Synthesis and Properties, Khan, Z. H., Springer Singapore, (2017).[2] Narita, A., Wang, X.-Y., Feng, X. & Müllen, K. New advances in nanographene chemistry. Chem. Soc. Rev. 44, 6616–6643 (2015).[3] Wang, X.-Y., Yao, X. & Müllen, K. Polycyclic aromatic hydrocarbons in the graphene era. Sci. China Chem. 62, 1099–1144 (2019)[4] Zhao, S. et al. Single photon emission from graphene quantum dots at room temperature. Nat. Commun. 9, 3470 (2018).[5] D. Medina-Lopez et al., submitted Figure 1

Evaluating Antimicrobial Activity and Wound Healing Effect of Rod-Shaped Nanoparticles.

Presently, the nanotechnology approach has gained a great concern in the media of drug delivery. Gold nanoparticles (Au-NPs) specially having a non-spherical structure, such as gold nanorods (GNR), are attracting much interest as antibacterial agent and many other medical fields. The aim of the current investigation was to characterize Au-NPs and investigate their antimicrobial and wound healing efficacy in diabetic animals. Material and methods: Au-NPs were characterized using a UV-Vis spectrophotometer, estimating their particle size, polydispersity (PDI), and assessing their morphological characters. Further, Au-NPs were estimated for their antibacterial and antifungal behavior. Ultimately, in vivo activity of Au-NPs was evaluated against excision wound healing in STZ-induced diabetic animals. Results: Au-NPs were found to show maximum absorption at 520 nm. They exhibited a particle size of 82.57 nm with a PDI value of 0.323. Additionally, they exhibited good antimicrobial activity against different bacterial strains. Topical application of Au-NPs caused a significantly increased percentage of wound area reduction, lesser time needed for epithelialization, and augmented hydroxyproline, collagen, and hexosamine levels demonstrating enhanced healing processes. Furthermore, Au-NPs displayed a significant intensification in angiogenesis-related factors (HIF-1α, TGF-β1, and VEGF), and antioxidant enzymes activities (CAT, SOD, GPx) as well as mitigated inflammatory mediators IL-6, IL-1β, TNF-α, and NF-κB) and lipid peroxidation (MDA). Conclusion: Au-NPs exhibited proper particle size, and rod-shaped particles, with efficient antimicrobial behavior against different bacterial strains. Furthermore, Au-NPs demonstrated a promising wound healing activity in STZ-induced diabetic animals.

Silver nanoparticles penetration in dentin: Implications for long-term caries arrestment

The effectiveness of silver nanoparticles (AgNPs) as a caries arrestment agent was demonstrated in clinical trials some years ago; however, the mechanisms underlying their action remain unclear. It was hypothesized that the AgNPs could penetrate the dentinal tubules, contributing to their enduring cariostatic activity. The experiments were carried out with teeth samples with the incisal coronal third removed with a rotating diamond disk, exposing the dentin beneath the enamel to simulate shallow occlusal caries lesions. The dentin surfaces were treated with two different AgNP colloids: (i) spherical nanoparticles (7.5 nm) and (ii) a mixture of spherical (24.3 nm), triangular (33.8 nm), and rod-shaped (40.1/18.8 nm) nanoparticles. The samples were analyzed by scanning electron microscopy (SEM) and focused-ion beam SEM (FIB-SEM), allowing for the observation of the inner areas of the dentin. It was observed that AgNPs are able to penetrate dentinal tubules and adhere to their walls. The depth depends on the exposure time of the dentin surface to the colloid and the average nanoparticle size. The smaller the nanoparticles and the longer the exposure time, the deeper their penetration. At maximum, the AgNPs were detected up to 362.1 µm from the surface. The total silver amount in the sub-surface intra-tubular dentin was estimated to be within the concentration range expected to inhibit bacterial growth. The maximum penetration depth detected is shallow enough to avoid AgNP contact with the dental pulp.

Green fabrication of silver nanoparticles using Chloroxylon swietenia leaves and their application towards dye degradation and food borne pathogens

Green synthesized silver nanoparticles (AgNPs) are becoming an important candidate for bioremediation and biomedical applications. But in recent trends, more focus is given towards degradation of dyes and application against food pathogens. The synthesis of efficient AgNPs depends on the selection of potential biological material for synthesis. Therefore, in the present study, AgNPs were synthesized using Chloroxylon swietenia. The synthesis AgNPs was confirmed by the formation of dark brown precipitate. Further physicochemical characterization performed using XRD, FTIR, SEM and DLS showed the formation of crystalline structure, presence of functional group from the C. swietenia, dispersed spherical and rod-shaped nanoparticles (6.9 nm) and possess good stability due to the negative partial charges. The dye degrading efficacy of Chloroxylon swietenia mediated synthesized AgNPs (C-AgNPs) was >95%, 90% and >90% tested against Congo red (CR), Coomassie blue (CB) and crystal violet (CV) dye, respectively withing 24 h of treatment under optimum conditions. The antibacterial activity of C-AgNPs (10 mg/mL) was analysed against Staphylococcus nepalensis (3.03 ± 0.35 cm), Staphylococcus gallinarum (2.96 ± 0.15 cm), Bacillus subtilis (2.86 ± 0.23 cm), Enterococcous faecalis (2.8 ± 0.30 cm) and Pseudomonas stuteria (2.06 ± 0.25 cm) using Disc diffusion method, Minimum inhibitory concentration (MIC) and Minimum bactericidal activity (MBC). Therefore, the present study is the first and foremost report on C-AgNPs application as dye degrading and antibacterial agents against food dyes and pathogens. This will provide a major strategy to unveil the complications in food and packaging industries worldwide.

Polymeric Nanotubes as Drug Delivery Vectors─Comparison of Covalently and Supramolecularly Assembled Constructs

Rod-shaped nanoparticles have been identified as promising drug delivery candidates. In this report, the in vitro cell uptake and in vivo pharmacokinetic/bio-distribution behavior of molecular bottle-brush (BB) and cyclic peptide self-assembled nanotubes were studied in the size range of 36–41 nm in length. It was found that BB possessed the longest plasma circulation time (t1\\2 > 35 h), with the cyclic peptide system displaying an intermediate half-life (14.6 h), although still substantially elevated over a non-assembling linear control (2.7 h). The covalently bound BB underwent substantial distribution into the liver, whereas the cyclic peptide nanotube was able to mostly circumvent organ accumulation, highlighting the advantage of the inherent degradability of the cyclic peptide systems through their reversible aggregation of hydrogen bonding core units.

The strategy for organic dye and antibiotic photocatalytic removal for water remediation in an example of Co-SnO2 nanoparticles

A challenging problem to create an efficient photocatalyst suitable for industrial water remediation, aiming to remove cyclic organic compounds attracts increasing attention. The current study aimed to clarify a few “dark spots” in the field, namely to find out if it is possible to make an efficient photocatalyst activated with visible light by using a simple and cheap strategy and what are the key factor impacting its efficiency. In this work, a new procedure to obtain spherical nanoparticles with the same average size but different amounts of oxygen vacancies and defects and dopant concentrations was developed. The approach based on hydrothermal treatment was suggested to obtain rod-shaped nanoparticles. The systematic study of photocatalytic behavior on the example of oxytetracycline and methylene blue degradation under visible light of widely available LED lamp was performed. Based on chemical and computational experiments the main factor affecting the process efficiency was determined.

Luteolin mediated synthesis of rod-shaped rutile titanium dioxide nanoparticles: Assay of their biocompatibility

Titanium dioxide nanoparticles (TiO2NPs) were produced using a crud flavonoid luteolin (LT) by the green process. Physicochemical characterizations of LT mediated synthesis of TiO2NPs (LT-TiO2NPs) were analyzed by different techniques. The biocompatibility of LT-TiO2NPs was evaluated by assessing their cytotoxicity, inhibition of protein denaturation, hemolysis effects, and membrane stabilization activity. The synthesized LT-TiO2NPs exhibited mostly rod-shaped morphology, rutile crystalline structure with length about 33.3–135 nm and width in 16.6–58 nm. Under LT-TiO2NPs treatments, the cell viability of cancer cells was decreased in a dose-dependent manner. According to the results, the IC50 values of LT-TiO2NPs were between 12.5–25 μg/mL for A375 and MCF-7 cancer cells, and its value was below 50 μg/mL for skin fibroblast. These NPs also induced intracellular reactive oxygen species (ROS) generation and caused mitochondrial disruption in cancer cells, leading to the induction of intrinsic apoptosis. These biosynthesized NPs did not show denaturation of bovine serum albumin (BSA) protein and hemolytic or heat-induced hemolytic effects, which confirmed their membrane stabilization activity without damaging red blood cells (RBCs) membrane integrity. Therefore, this research provides valuable results in the case of green synthesis of LT-TiO2NPs and their specific properties, biocompatibility, and their potential to be used in biomedical fields.

Gold Nanorods for Drug and Gene Delivery: An Overview of Recent Advancements.

Over the past few decades, gold nanomaterials have shown great promise in the field of nanotechnology, especially in medical and biological applications. They have become the most used nanomaterials in those fields due to their several advantageous. However, rod-shaped gold nanoparticles, or gold nanorods (GNRs), have some more unique physical, optical, and chemical properties, making them proper candidates for biomedical applications including drug/gene delivery, photothermal/photodynamic therapy, and theranostics. Most of their therapeutic applications are based on their ability for tunable heat generation upon exposure to near-infrared (NIR) radiation, which is helpful in both NIR-responsive cargo delivery and photothermal/photodynamic therapies. In this review, a comprehensive insight into the properties, synthesis methods and toxicity of gold nanorods are overviewed first. For the main body of the review, the therapeutic applications of GNRs are provided in four main sections: (i) drug delivery, (ii) gene delivery, (iii) photothermal/photodynamic therapy, and (iv) theranostics applications. Finally, the challenges and future perspectives of their therapeutic application are discussed.

Spherical and rod shaped mesoporous silica nanoparticles for cancer-targeted and photosensitizer delivery in photodynamic therapy

Mesoporous silica nanoparticles (MSNPs) have attracted much attention in many biomedical applications. One of the fields in which smart functional nanosystems have found wide application is cancer treatment. Here, we present new silica nanoparticle-based systems which have been explored as efficient vehicles to transport and deliver photosensitizers (PSs) into tumor tissues during photodynamic therapy (PDT). In this work, we report the preparation, characterization, and in vitro studies of distinct shaped MSNPs grafted with S-glycoside porphyrins (Pors). The ensuing nanomaterials were fully characterized, and their properties as third-generation PSs for PDT against two bladder cancer cell lines, HT-1376 and UM-UC-3, were examined. The best uptake results were obtained for MSNP-PS2, while MSNP-PS1 showed the lowest cellular uptake among the nanocarriers tested, but revealed the best phototoxicity in both cancer cells. Overall, the phototoxicity was higher with MSNPs than with mesoporous silica nanorods (MSNRs) and higher uptake and phototoxicity were consistently observed in UM-UC-3 rather than in HT-1376 cancer cells.

A green synthesis of zinc oxide nanoparticles using Musa Paradisiaca and Rooibos extracts

This study describes the single pot synthesis of zinc oxide nanoparticles (ZnO NPs) using a mixture of Aspalathus linearis and Musa paradisiaca for use against the fungi Candida albicans. These nanoparticles are known to be one of the most multifunctional inorganic nanoparticles with effective antifungal and antibacterial activity. The synthesized ZnONPs were characterized by a peak at 290 nm in the UV–vis spectrum while HRSEM confirmed rod-shaped nanoparticles. The FTIR data clearly revealed that the extracts contained -OH functional groups whose role was capping agents during the nanoparticle synthesis. This study also found that the purity of the green synthesised ZnO NPs (GZnO NPs) was 94.4 %, 91.5 %, and 82.1 %, respectively, using XRD, HRTEM, and HRSEM-EDS. The antifungal activity of ZnONPs was tested against Candida albicans using the Kirby Bauer method. The maximum inhibition zone observed in the ZnO NPs against Candida albicans was confirmed to be 24 mm, a clear indication that the synthesized ZnO NPs have great potential to act as effective antifungal agents.•Zinc nitrate hexahydrate [Zn(NO3)2·6H2O] was used as the inorganic metal oxide precursor.•Extracts of banana (Musa paradisiaca) peel and tea leaves of Rooibos (Aspalathus linearis) infused with Buchu (Agathosma betulina) were the organic constituents used as reducing and capping agents during GZnO NPs synthesis.•Validation of the formed GZnO NPs was done using; Ultraviolet-visible spectroscopy (UV-Vis), X-ray spectroscopy (XRD), Fourier-transform Infrared Spectroscopy (FTIR), High-resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED), and High-Resolution Scanning Electron Microscopy with Energy-Dispersive Spectroscopy (HRSEM-EDS).

Shaping nanoparticle diffusion through biological barriers to drug delivery

Nanoparticle drug delivery systems encounter many biological barriers, such as the extracellular matrix and mucus gels, that they must bypass to gain access to target cells. A design parameter that has recently gained attention is nanoparticle shape, as it has been shown elongated rod–shaped nanoparticles achieve higher diffusion rates through biological gels. However, the optimal dimensions of rod-shaped nanoparticles to enhance this effect has yet to be established. To systematically approach this, rod-shaped nanoparticles were synthesized by mechanically stretching 100 ​nm, 200 ​nm, and 500 ​nm spherical nanoparticles. Transmission electron microscopy confirmed this procedure yields a significant fraction of elongated rods and remaining spheres could be removed by centrifugation. Fluorescent microscopy and multiple particle tracking analysis was then used to characterize rod-shaped and spherical nanoparticle diffusion in MaxGel®, a model extracellular matrix hydrogel. When dispersed in MaxGel, we found rod-shaped nanoparticles exhibited the greatest enhancement in diffusion rate when their length far exceeds the average hydrogel network size. These results further establish the importance of shape as a design criterion to improve nanoparticle-based drug delivery systems.

Unit-cell wide SBA-15 type mesoporous silica nanoparticles

With large and 2D hexagonally ordered mesopores, SBA-15 is the superstar among mesoporous silicas reported so far and has found many applications. To prepare SBA-15 nanoparticles is of particular interest for biomedical application yet remains challenging. In this work, rod-shaped SBA-15 nanoparticles (SBA-15NPs), with 2–3 mesopore channels in width (called unit-cell wide) and averaged length of 94.8 nm, are for the first time prepared in a boric acid catalyzed P123 templating system based on the partitioned cooperative self-assembly principle in a one-pot preparation. The BET surface area and total pore volume of typical SBA-15NPs reach 553 m2g-1 and 1.52 cm3g-1, respectively. The preparation of SBA-15NPs relies on PCSA process that bestows long and thin tubular SBA-15 pre-structures with many defects in low-temperature synthesis step, which are then cut into SBA-15NPs by a sulfuric acid enhanced Ostwald ripening process in hydrothermal treatment step. In enzyme adsorption tests, SBA-15NPs demonstrate higher capacity and faster adsorption compared with conventional rod-shaped SBA-15.

Rod-shaped keratin nanoparticles extracted from human hair by acid hydrolysis as photothermally triggered berberine delivery system

Human hair can be a sustainable keratin source to prepare cytocompatible drug nanocarriers. A simple and effective methodology to create rod-like keratin nanoparticles (KNPs) using acidic hydrolysis was reported in this work. The extracted KNPs were characterized by infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal analysis (TG and DSC), Zeta potential measurements, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The KNPs presented an amorphous structure with a smaller average size and higher aspect ratio than KNPs created from previously reported alkaline methods. Furthermore, cell viability assays confirmed that the extracted KNPs are cytocompatible toward adipose mesenchymal stem cells (ADSCs) and healthy cells of the African green monkey (VERO cells). The material was evaluated as berberine (BERB) nanocarrier, a drug with anticancer activity. The BERB was associated with KNPs by adsorption. The rod-shaped KNPs presented a type II adsorption profile toward BERB, adsorbing approximately 168.05 ± 1.44 mg/g. BERB is a cationic species capable of interacting with negatively charged KNPs (Zeta potential equal to −33.8 mV at pH 8.0). After BERB adsorption, the KNPs/BERB Zeta potential is reduced to −10.14 mV (pH 8.0). The KNPs exhibited strong photothermal properties, which improved and enhanced the BERB desorption. The photothermal KNPs responsiveness promoted a sustained BERB release. The KNPs/BERB shows cytotoxity against colon adenocarcinoma cells (HT-29 cells). Therefore, the extracted rod-shaped KNPs can be alternative nanocarriers for BERB delivery.