Desired Particle Size Research Articles

Anti-EGFR antibody conjugated silica nanoparticles as probes for lung cancer detection.

A well-designed nanosystem [anti-epidermal growth factor receptor-MB-encapsulated thiol-terminated silica nanoparticles (EGFR/MB-SHSi) complexes] containing silica nanoparticles and near-infrared fluorescence dye (NIRF) methylene blue (MB) was established as a tumor-targeted probe for potential lung cancer detection. The anti-EGFR/MB-SHSi complexes exhibited desirable and homogenous particle size, high bovine serum albumin stability, low hemolytic activity, neutral surface charges and negligible cytotoxicity in vitro. Furthermore, the results of confocal laser scanning microscopy and flow cytometry confirmed that the EGFR-targeted function induced high and specific cellular uptake of anti-EGFR/MB-SHSi complexes. In vivo investigation of nude mice bearing A549 tumor xenografts revealed that anti-EGFR/MB-SHSi complexes possessed strong tumor target ability. These observations indicated that anti-EGFR/MB-SHSi complexes may be a safe and tumor-targeting probe for the detection of cancer.

Development and evaluation of long-circulating nanoparticles loaded with betulinic acid for improved anti-tumor efficacy

The clinical application of betulinic acid (BA), a natural pentacyclic triterpenoid with promising antitumor activity, is hampered due to its extremely poor water solubility and relatively short half-life in the systemic circulation. In order to address these issues, herein, we developed betulinic acid loaded polylactide-co-glycolide- monomethoxy polyethylene glycol nanoparticles (PLGA-mPEG NPs). The PLGA-mPEG co-polymer was synthesized and characterized using NMR and FT-IR. BA loaded PLGA-mPEG NPs were prepared by an emulsion solvent evaporation method. The developed nanoparticles had a desirable particle size (∼147nm) and exhibited uniform spherical shape under transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The PLGA-mPEG NPs were able to decrease the uptake by macrophages (i.e. J774A.1 and Raw 264.7 cells) as compared to PLGA nanoparticles. In vitro cytotoxicity in MCF7 and PANC-1 cells demonstrated enhanced cytotoxicity of BA loaded PLGA-mPEG NPs as compared to free BA. The cellular uptake study in both the cell lines demonstrated time dependent uptake behavior. The enhanced cytotoxicity of BA NPs was also supported by increased cellular apoptosis, mitochondrial membrane potential loss, generation of high reactive oxygen species (ROS) and cell cycle arrest. Further, intravenous pharmacokinetics study revealed that BA loaded PLGA-mPEG NPs could prolong the circulation of BA and remarkably enhance half-life by ∼7.21 folds. Consequently, in vivo studies in Ehrlich tumor (solid) model following intravenous administration demonstrated superior antitumor efficacy of BA NPs as compared to native BA. Moreover, BA NPs treated Ehrlich tumor mice demonstrated no biochemical, hematological and histological toxicities. These findings collectively indicated that the BA loaded PLGA-mPEG NPs might serve as a promising nanocarrier for improved therapeutic efficacy of betulinic acid.

Design and development of a biocompatible montmorillonite PLGA nanocomposites to evaluate in vitro oral delivery of insulin

We are introducing design, development and preliminary feasibility study of nanocomposites (made of Food and drug administration approved layered montmorillonite (Mt) and biodegradable polymer Poly lactic-co-glycolic acid (PLGA)), as a vehicle for oral administration of insulin. A systematic study on the variation of Mt-PLGA ratio was focused to reduce particles to the submicron size range while maintaining insulin's bioactivity. The synthesized Insulin-Mt-PLGA nanocomposites were successfully characterized with various techniques and compared with the Insulin-PLGA nanoparticles for their drug content, physico-chemical properties, in-vitro insulin release profile and cytotoxicity. High encapsulation efficiency, desirable particle size, prolonged gastric residence time, extended release of insulin in simulated gastrointestinal fluid and biocompatibility indicated the effectiveness of presence of Mt in the synthesized Mt-PLGA nanocomposites for the oral delivery of insulin. Thus, on the basis of our preliminary research findings, it could be concluded that the developed biocompatible Insulin-Mt-PLGA nanocomposites with double functionality of low pH stability and mucoadhesivity may offers promise to overcome the difficulties associated with the oral drug delivery of insulin.

다구찌 기법과 다상유동해석을 이용한 분급기 운전조건 최적화

Generally, classifiers have been used as machines to crush raw materials and classify suitable particle sizes in all industrial fields, such as food, chemical, and mineral. However, the technique for classifying micron-sized particles between 5 and 20 μm is inferior. In particular, numerous experiments and considerable experiences are required to predict the particle size, because the classifier particle size is determined according to the internal flow. However, it is quite difficult to set the driving conditions so that the desired particle size can be classified only by experience and experimentation. Therefore, this study proposes a method of predicting the average particle size by employing multiphase flow analysis and the Taguchi method; this method is subsequently verified.

TPGS-Functionalized Polydopamine-Modified Mesoporous Silica as Drug Nanocarriers for Enhanced Lung Cancer Chemotherapy against Multidrug Resistance.

A nanocarrier system of d-a-tocopheryl polyethylene glycol 1000 succinate (TPGS)-functionalized polydopamine-coated mesoporous silica nanoparticles (NPs) is developed for sustainable and pH-responsive delivery of doxorubicin (DOX) as a model drug for the treatment of drug-resistant nonsmall cell lung cancer. Such nanoparticles are of desired particle size, drug loading, and drug release profile. The surface morphology, surface charge, and surface chemical properties are also successfully characterized by a series of techniques such as transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) method, thermal gravimetric analysis (TGA), dynamic light scattering (DLS), and Fourier transform infrared spectroscopy (FTIR). The normal A549 cells and drug-resistant A549 cells are employed to access the cytotoxicity and cellular uptake of the NPs. The therapeutic effects of TPGS-conjugated nanoparticles are evaluated in vitro and in vivo. Compared with free DOX and DOX-loaded NPs without TPGS ligand modification, MSNs-DOX@PDA-TPGS exhibits outstanding capacity to overcome multidrug resistance and shows better in vivo therapeutic efficacy. This splendid drug delivery platform can also be sued to deliver other hydrophilic and hydrophobic drugs.

P-gp modulatory acetyl-11-keto-β-boswellic acid based nanoemulsified carrier system for augmented oral chemotherapy of docetaxel

In spite of being a very potent and promising drug against many types of cancer, docetaxel suffers the disadvantage of low solubility and poor bioavailability rendering it unsuitable for oral administration. Also, the available marketed formulation for intravenous administration has its inherent drawbacks owing to the presence of polysorbate 80. Here, we exploited the anticancer and P-gp inhibitory potential of naturally occurring frankincense oil to fabricate a stable docetaxel loaded nanoemulsified carrier system for oral delivery. The nanoemulsion possessing desirable particle size (122±12nm), polydispersity (0.086±0.007) and zeta potential (−29.8±2.1mV) was stable against all type of physical stresses and simulated physiological conditions tested. The formulation showed higher uptake in Caco-2 cells and inhibited P-gp transporter significantly (P<0.05). In MDA-MB-231 cells, it showed less IC50, arrested cells in G2-M phase and exhibited higher degree of apoptosis than marketed formulation Taxotere®. The 182.58±4.16% increment in relative oral bioavailability led to higher in vivo anti-proliferative activity manifesting 19% more inhibition than Taxotere®. Conclusively, it is revealed that the developed nanoemulsion will be a propitious approach towards alternative docetaxel therapy.

Understanding the effect of synthesis parameters on the catalytic ionic liquid hydrolysis process of cellulose nanocrystals

Conventional production of cellulose nanocrystals (CNC) normally encounters several problems including high energy consumption, toxicity and corrosion risk. Implementation of green solvent ionic liquid (IL) is an alternative to this conventional method. Production of CNC is known to be influenced by several factors such as reaction time and temperature. However, limited studies on the regeneration yield and other properties of CNC produced at both variables can be found. In this paper, CNC with desirable yield, crystallinity and particle size has been produced under catalytic hydrolysis process of IL. Two different parameters have been studied which are reaction temperature and time. It was found that, CNC with particle size of 9 nm and 73% crystallinity index has been produced at 30 min reaction time. Meanwhile, 100 °C reaction temperature manages to produce CNC with 90% yield and 76% crystallinity. In conclusion, reaction temperature and time affect the yield and thermal properties of hydrolysis process.

Folate-decorated PEGylated triblock copolymer as a pH/reduction dual-responsive nanovehicle for targeted intracellular co-delivery of doxorubicin and Bcl-2 siRNA

Co-delivery of chemotherapeutic drug and small interfering RNA (siRNA) within a single nanovehicle has emerged as a promising combination therapy approach to treating cancers because of their synergistic effect. Nanocarrier delivery systems with low cytotoxicity and high efficiency are needed for such a purpose. In this study, a novel folate-conjugated PEGylated cationic triblock copolymer, poly(acrylhydrazine)-block-poly(3-dimethylaminopropyl methacrylamide)-block-poly(acrylhydrazine) (PAH-b-PDMAPMA-b-PAH), was synthesized and evaluated as a stimuli-sensitive vehicle for the targeted co-delivery of doxorubicin (DOX) and Bcl-2 siRNA into breast cancer MCF-7 cells. The synthetic process of the PEGylated triblock copolymer involved sequential reversible addition-fragmentation chain transfer polymerization, PEGylation and removal of tert-butoxy carbamate protecting groups. Folate-conjugated and/or -unconjugated poly(ethylene glycol) segments were grafted onto PAH-b-PDMAPMA-b-PAH via a reduction-sensitive disulfide linkage. The synthetic polymers were characterized by 1H NMR and gel permeation chromatography. The PEGylated triblock copolymer could chemically conjugate DOX onto PAH blocks via pH-responsive hydrazone bonds and simultaneously complex negatively charged Bcl-2 siRNA with cationic PDMAPMA blocks through electrostatic interactions at N/P ratios≥32:1 to form multifunctional nanomicelleplexes. The nanomicelleplexes exhibited spherical shape, possessed a positively charged surface with a zeta potential of +22.5mV and had a desirable and uniform particle size of 187nm. In vitro release studies revealed that the nanomicelleplexes could release DOX and Bcl-2 siRNA in a reduction and pH dual-sensitive manner and the payload release was significantly enhanced in a reductive acidic environment mimicking the endosomes/lysosomes of cancer cells compared to under physiology conditions. Furthermore, the release of both DOX and siRNA was found to follow Higuchi kinetic model. Confocal laser scanning microscopy, flow cytometry and MTT analyses confirmed that, compared with folate-undecorated nanomicelleplexes, folate-decorated nanomicelleplexes could more effectively co-deliver DOX and Bcl-2 siRNA into MCF-7 cells and showed a stronger cell-killing effect. The pristine PEGylated triblock copolymer exhibited good cytocompatibility. Moreover, co-delivery of DOX and Bcl-2 siRNA achieved a significant synergistic antitumor efficacy. These findings suggested that the folate-decorated PEGylated cationic triblock copolymer might be a promising vehicle for targeted intracellular co-delivery of DOX and siRNA in MCF-7 cells, representing a potential clinical combination therapy for breast cancer treatment.

An image based clump library for DEM simulations

To create realistic virtual soil specimens for Discrete Element Method simulations, a library containing nearly 100,000 “clumps” was developed. A clump essentially models a soil particle. It consists of numerous overlapping spheres in 3D, or circles in 2D, that are tangent to the particle perimeter. By using a unique corner-preserving algorithm based on the classic 2D definition of particle roundness, the clump generation requires many fewer circles than by previous algorithms. In this paper, the clumps are based on 2D images of real soil particles and they are indexed in the library by their roundness R and sphericity S values. A real soil can be simulated by choosing particles from the library to match the soil’s actual distributions of R and S. The clumps are also enlarged or reduced to match a desired particle size distribution. The utility of the clump library in parametric studies was demonstrated by direct shear tests on five very different virtual materials created from clumps in the library.

Design of lipid-polymer hybrid nanoparticles for therapy of BPH: Part I. Formulation optimization using a design of experiment approach

The primary purpose of the present research was to design a novel lipid-polymer hybrid nanoparticulate system of lonidamine based on the DoE approach for the effective treatment of benign prostatic hyperplasia. Hybrid nanoformulations were prepared through one-step self-assembly approach. The primary core material used PLGA, while DSPE-PEG-COOH and l-α-phosphatidylcholine were employed as lipid-PEG shell layer and lipid monolayer at the interface of the lipid-PEG shell and polymeric core, respectively. The molar ratios of PEG conjugated lipid to polymer and total lipids to l-α-phosphatidylcholine were determined as the investigated independent variables. Nine hybrid formulations were optimized by the application of a 32 factorial design to evaluate the major changes on the characteristics of hybrid systems such as entrapment efficiency, mean particle size and surface charge. Shape and morphology characteristics, in vitro release profiles, thermal behavior and interactions, lipid shell thickness, and storage stability were also evaluated. The important outcomes of this research revealed that the hybrid formulations prepared at the center point of the design exhibited an excellent core-shell structure, high entrapment efficiency values, and desired particle sizes. The linearity graphics and the surface response plots demonstrated significant effectiveness between the independent variables and the experimental responses.

Mannose-coated gadolinium liposomes for improved magnetic resonance imaging in acute pancreatitis.

BackgroundAcute pancreatitis (AP) is an acute inflammatory condition of the pancreas. The symptoms, treatment, and prognosis of mild and severe AP are different, and severe AP is a potentially life-threatening disease with a high incidence of complications and high mortality rate. Thus, it is urgent to develop an effective approach to reliably discriminate between mild and severe AP.MethodsWe have developed novel gadolinium-diethylenetriaminepentaacetic (Gd-DTPA)-loaded mannosylated liposomes (named thereafter M-Gd-NL) that preferably target macrophages in AP. The targeting ability of M-Gd-NL toward macrophages in AP and its ability to discriminate between mild and severe AP were evaluated.ResultsThe liposomes were of desired particle size (~100 nm), Gd-DTPA encapsulation efficiency (~85%), and stability. M-Gd-NL and non-targeted Gd-DTPA-loaded liposomes (Gd-NL) exhibited increased relaxivity compared with Gd-DTPA. Compared with Gd-NL and Gd-DTPA, M-Gd-NL showed increased uptake in macrophages, resulting in increased T1 imaging ability both in vitro (macrophage cell line) and in vivo (severe AP model). Importantly, M-Gd-NL had the ability to discriminate between mild and severe AP, as reflected by a significantly higher T1 magnetic resonance imaging signal in severe AP than in mild AP. M-Gd-NL did not show severe organ toxicity in rats.ConclusionOur data suggest that M-Gd-NL had enhanced magnetic resonance imaging ability by targeting macrophages in AP and good ability to discriminate between mild and severe AP. We believe that M-Gd-NL could shed new light on the diagnosis of AP in the near future.

Orally Targeted Delivery of Tripeptide KPV via Hyaluronic Acid-Functionalized Nanoparticles Efficiently Alleviates Ulcerative Colitis

Overcoming adverse effects and selectively delivering drug to target cells are two major challenges in the treatment of ulcerative colitis (UC). Lysine-proline-valine (KPV), a naturally occurring tripeptide, has been shown to attenuate the inflammatory responses of colonic cells. Here, we loaded KPV into hyaluronic acid (HA)-functionalized polymeric nanoparticles (NPs). The resultant HA-KPV-NPs had a desirable particle size (∼272.3nm) and a slightly negative zeta potential (∼-5.3mV). These NPs successfully mediated the targeted delivery of KPV to key UC therapy-related cells (colonic epithelial cells and macrophages). In addition, these KPV-loaded NPs appear to be nontoxic and biocompatible with intestinal cells. Intriguingly, we found that HA-KPV-NPs exert combined effects against UC by both accelerating mucosal healing and alleviating inflammation. Oral administration of HA-KPV-NPs encapsulated in a hydrogel (chitosan/alginate) exhibited a much stronger capacity to prevent mucosa damage and downregulate TNF-α, thus they showed a much better therapeutic efficacy against UC in a mouse model, compared with a KPV-NP/hydrogel system. These results collectively demonstrate that our HA-KPV-NP/hydrogel system has the capacity to release HA-KPV-NPs in the colonic lumen and that these NPs subsequently penetrate into colitis tissues and enable KPV to be internalized into target cells, thereby alleviating UC.

Oral delivery of curcumin via porous polymeric nanoparticles for effective ulcerative colitis therapy.

Oral drug delivery has been considered as a promising strategy for ulcerative colitis (UC) therapy. Here, an emulsion solvent evaporation technique was employed to prepare non-porous curcumin (CUR)-loaded polymeric nanoparticles (NPs) and porous CUR-loaded polymeric NPs in the absence or presence of ammonium bicarbonate. The resultant CUR-loaded NPs (non-porous NPs and porous NPs) had a desirable mean particle size of around 260 nm with a narrow size distribution, a uniform pore size distribution, slightly negative-charged surface, high encapsulation efficiency and controlled drug release capacity. In vitro experiments indicated that Raw 264.7 macrophages exhibited time-dependent accumulation profiles of NPs during the initial 2 h of co-incubation. Furthermore, we found that porous NPs inhibited the secretion of the main pro-inflammatory cytokines (TNF-α, IL-6 and IL-12) and the production of reactive oxygen species much more efficiently than non-porous NPs. Most importantly, in vivo studies demonstrated that oral administered porous NPs had a superior therapeutic efficiency in alleviating UC compared with non-porous NPs. The results collectively suggest that porous polymeric NPs can be exploited as efficient oral drug carriers for UC treatment.

Preparation and In Vitro Evaluation of Biodegradable Microspheres with Narrow Size Distribution for Pulmonary Delivery

This study was performed to evaluate the feasibility of double emulsion technique combined with membrane emulsification to prepare microspheres for pulmonary delivery. An attempt was made to counter the shortcomings of microspheres; unsuitable size diameters and broad size distribution. Three formulation variables were optimized in order to achieve desired particle size and narrow size distribution. Compared with microspheres prepared by conventional double emulsion technique, the microsphere morphology, aerodynamic particle size, drug encapsulation efficiency and in vitro release were characterized in detail. The particles prepared by double emulsion technique combined with membrane emulsification showed the advantage on controlling the particle size to meet the requirement of respiration, as well as on encapsulation efficiency. Overall, this strategy could be promising for the application of pulmonary delivery.

Periodic cells for large-scale problem initialization

In geotechnical applications the success of the discrete element method (DEM) in simulating fundamental aspects of soil behaviour has increased the interest in applications for direct simulation of engineering scale boundary value problems (BVP’s). The main problem is that the method remains relatively expensive in terms of computational cost. A non-negligible part of that cost is related to specimen creation and initialization. As the response of soil is strongly dependant on its initial state (stress and porosity), attaining a specified initial state is a crucial part of a DEM model. Different procedures for controlled sample generation are available. However, applying the existing REV-oriented initialization procedures to such models is inefficient in terms of computational cost and challenging in terms of sample homogeneity. In this work a simple but efficient procedure to initialize large-scale DEM models is presented. Periodic cells are first generated with a sufficient number of particles matching a desired particle size distribution (PSD). The cells are then equilibrated at low-level isotropic stress at target porosity. Once the cell is in equilibrium, it is replicated in space in order to fill the model domain. After the domain is thus filled a few mechanical cycles are needed to re-equilibrate the large domain. The result is a large, homogeneous sample, equilibrated under prescribed stress at the desired porosity. The method is applicable to both isotropic and anisotropic initial stress states, with stress magnitude varying in space.

Effect of Starter Culture and Encapsulated Lactic Acid on the Quality and Storage Stability of Nutrient Multicomponent Dry Chicken Sausages

ObjectivesThere is a need to develop safe, nutritious, and shelf stable meat products that can be stored without refrigeration, especially in energy deficient countries. To achieve safe and shelf stable foods pH and water activity (aw) targets must be achieved. Lowering product pH can be accomplished through the use of acidulants (encapsulated lactic acid) or through fermentation with starter cultures. The objectives of this study were: to compare the effect of encapsulated lactic acid (ELA) and starter culture (SC) acidulation on the qualities of multicomponent dry chicken sausage, and to investigate its stability at 25 and 50°C.Materials and MethodsChicken sausages were manufactured using fresh chicken breasts and thighs, 156 ppm NaNO2 (ingoing), incorporating an Indian-based spice blend, walnuts and dried dates. The product was manufactured by blending all ingredients and chopping to the desired particle size, and then stuffed into cellulosic casings (27 mm). ELA or SC were added directly during mixing. Sausages made with SC (Saga 200, 1% addition of dextrose) were fermented for 10 h at 37.8°C. Acidulation and drying were optimized to achieve a target pH ≤ 5.2 and aw ≤ 0.85. After thermal processing to an internal temperature of 73.9°C, drying and chilling, casings were removed and the sausages were vacuum-packaged. Sausages were stored at either 25 or 50°C for evaluation on d 0, 7, 14, and 28. On each storage day, moisture, protein, moisture protein ratio (MPR), water activity (aw), pH, thiobarbituric acid reactive substances (TBARS), instrumental color (L*, a*, b*) values were measured. Kramer shear values (SFV) were determined on d 0 samples. The experiment was replicated three times.ResultsGreater (P < 0.05) product yield was recorded for sausages made with ELA (61.35%) compared to SC (59.39%) due to differences in product pH after processing (5.3 versus 4.5) although the ELA sausage pH decreased over storage time. The ELA sausages had a higher (P < 0.05) MPR, aw (0.85), pH (5.31), and L* color values compared to SC sausages which can be attributed to product pH differences. A significant (P < 0.05) storage temperature × storage day interaction was observed for moisture and protein content, MPR, aw (varied from 0.85 to 0.83), pH (4.93 to 4.56), color and TBARS values. The interaction of acidulation method and storage temperature was significant (P < 0.05) for pH (5.31 to 4.44), a*, and b* values. The TBARS values increased significantly (P < 0.05) from d 0 to 28 (0.19 mg/kg malonaldehyde compared to 0.36, respectively). SFV of the sausages were significantly (P < 0.05) higher for SC (11.41 N/g) than for ELA (10.03 N/g).ConclusionMulticomponent dry chicken sausages prepared with either ELA or SC both maintained acceptable shelf stability and product quality during extended storage at either 25 or 50°C. However for countries or regions with food security issues (lack of refrigeration) the production of vacuum packaged dried chicken sausages using ELA may be preferred since it does not require refrigeration or controlled fermentation temperatures to acidulate product. Future research will investigate the safety and consumer acceptability of dried chicken sausages prepared with both ELA and SC.

Design and Optimization of Controlled Drug Delivery System of Losartan Potassium

Purpose : The objective of the study was to develop microspheres of Losartan potassium as controlled drug delivery system by using various polymer (HPMC and Ethylcellulose), evaluating the relationship and influence of different content levels of HPMC, and Ethylcellulose, in order to achieve a zero order release of Losartan potassium. Approach : Microspheres were prepared by solvent evaporation process. Release kinetics was evaluated by using United States Pharmacopoeia (USP) type I dissolution apparatus. The release mechanism of microspheres loaded with Losartan potassium was determined by fitting the data in Korsmeryer peppas equation. The regression coefficient values for Peppas model was found to be high, indicating adequate fitting. The 'n' value was ranged from 0.548 to 0.963 indicating Non Fickian diffusion for all the formulations. Optimization was performed by using desirability function. To validate the model, the optimized formula was subjected to in vitro characterization. Findings : Release kinetics of Losartan potassium from these microspheres was principally regulated by HPMC K4M and Ethylcellulose. Percentage yield, entrapment efficiency and particle size of optimized formula was found to be 91.42%, 68.01% and 310μm. Formulation (F1) release at the end of 12 hours of dissolution studies was found to be 79.81%. Conclusion : It can be concluded that Losartan potassium loaded microspheres could be successfully formulated by using HPMC 4KM and Ethylcellulose by solvent evaporation method to obtain maximum percentage yield, entrapment efficiency, desired particle size.

Effects of tripolyphosphate on cellular uptake and RNA interference efficiency of chitosan-based nanoparticles in Raw 264.7 macrophages

Tumor necrosis factor-α (TNF-α) is a major pro-inflammatory cytokine that is mainly secreted by macrophages during inflammation. Here, we synthesized a series of N-(2-hydroxy)propyl-3-trimethyl ammonium chitosan chlorides (HTCCs), and then used a complex coacervation technique or tripolyphosphate (TPP)-assisted ionotropic gelation strategy to complex the HTCCs with TNF-α siRNA (siTNF) to form nanoparticles (NPs). The resultant NPs had a desirable particle size (210–279nm), a slightly positive zeta potential (14–22mV), and negligible cytotoxicity against Raw 264.7 macrophages and colon-26 cells. Subsequent cellular uptake tests demonstrated that the introduction of TPP to the NPs markedly increased their cellular uptake efficiency (to nearly 100%) compared with TPP-free NPs, and yielded a correspondingly higher intracellular concentration of siRNA. Critically, in vitro gene silencing experiments revealed that all of the TPP-containing NPs showed excellent efficiency in inhibiting the mRNA expression level of TNF-α (by approximately 85–92%, which was much higher than that obtained using Oligofectamine/siTNF complexes). Collectively, these results obviously suggest that our non-toxic TPP-containing chitosan-based NPs can be exploited as efficient siTNF carriers for the treatment of inflammatory diseases.

Evaluation of Glabridin loaded nanostructure lipid carriers

Abstract Effective use of Glabridin (GL) is limited by poor solubility, poor stability and unsatisfactory skin penetration in cosmetic products. To reduce such limitations, GL was formulated into nanostructure lipid carriers (NLCs) as a controlled-released system. The preparation and performance in vitro were evaluated. The effects of surfactant ratio (F127/SG) on the size and zeta potential were studied. The desirable particle size and zeta potential were obtained on the basis of F127/SG (surfactant ratio) weight ratio of 1:2. Transmission electron microscopy (TEM) and Differential Scanning Calorimetry showed GL was loaded in solid lipid matrix. Compared to conventional emulsion, GL-NLCs achieved prolonged release and localized the drug significantly better in the skin. The solid lipid matrix of NLCs reduced transmission of UV-rays to GL and it also retained the photostability of GL. As such, these results suggest the potential of NLCs for Glabridin delivery in cosmetic application.

Mechanical Properties Based Particle Separation via Traveling Surface Acoustic Wave.

Most microfluidics-based sorting methodologies utilize size differences between suspended micro-objects as the defining characteristic by which they are sorted. Sorting based on mechanical properties, however, would provide a new avenue for sample preparation, detection and diagnosis for a number of emerging biological and medical analyses. In this study, we demonstrate separation of polystyrene (PS) and poly(methyl methacrylate) (PMMA) microspheres based entirely on their difference in mechanical properties using traveling surface acoustic waves (TSAWs). We theoretically examine the correlation of the applied TSAW frequency, particle density and sound speed with respect to the resultant acoustic radiation force (ARF) that acts to translate particles, and experimentally corroborate these predictions by translating PS and PMMA particles simultaneously in a stationary flow. Even when PS and PMMA particles have the same diameters, they exhibit strongly nonlinear and distinct acoustophoretic responses as a function of their mechanical properties and the applied TSAW frequency. By specifically matching the appropriate acoustic frequency to the desired particle size, each particle population can be selectively translated and sorted. We demonstrate that this mechanical property based sorting can continuously separate these particle populations with at least 95% efficiency in the mixed 10/15 μm diameter PS and PMMA particle solutions tested.