Albumin nanoparticles as carriers for a phosphodiester oligonucleotide

Nanoparticles target M2 macrophages to silence kallikrein-related peptidase 12 for the treatment of tuberculosis and drug-resistant tuberculosis

Matrix metalloproteinases (MMPs) are involved in the breakdown of lung extracellular matrix and the consequent release of Mycobacterium tuberculosis into the airways. Recent studies indicate that kallikrein-related peptidase 12 (KLK12) regulate MMP-1 and MMP-9, suggesting that targeting the KLK12 gene could be a promising tuberculosis (TB) treatment. To maximise therapeutic potential, this strategy of silencing KLK12 needs to be delivered to the pathogenic cell population while preserving the immunoprotective and tissue homeostatic functions of other lung macrophages. Our research found that KLK12 is highly expressed in M2 macrophages, leading us to design mannose-based bovine serum albumin nanoparticles (MBNPs) for delivering siRNA to silence KLK12 in these cells. The results of in vitro experiments showed that MBNPs could accurately enter M2 macrophages and sustainably release KLK12-siRNA with the help of mannose and mannose receptor targeting. The results of the in vivo experiments showed that MBNPs could reach the lungs within 1 h after intraperitoneal injection and peaked at 6 h. MBNPs increased collagen fibre content in the lungs by decreasing the levels of KLK12/MMPs thereby limiting the progression of TB. Importantly, MBNPs provided greater alleviation of pulmonary TB symptoms and reduced bacterial load in both TB and drug-resistant TB models. These findings provide an alternative and effective option for the treatment of TB, especially when drug resistance occurs. STATEMENT OF SIGNIFICANCE: RNA interference using small interfering RNA (siRNA) can target various genes and has potential for treating diseases such as tuberculosis (TB). However, siRNAs are unstable in the blood and within cells. This study presents bovine serum albumin nanoparticles encapsulating KLK12-siRNA (BNPs) synthesized via desolvation. A mannose layer was added (MBNPs) to target mannose receptors on M2 macrophages, facilitating endocytosis. The low pH-responsive MBNPs enhance lysosomal escape for siRNA delivery, downregulating the KLK12 pathway. Tests confirmed that MBNPs effectively inhibited Mycobacterium bovis proliferation, reduced granulomas, and decreased inflammation in a mouse model. This research aims to reduce antibiotic use, shorten treatment duration, and provide a novel TB treatment option.

Superparamagnetic Iron-Oxide Nanoparticles Synthesized via Green Chemistry for the Potential Treatment of Breast Cancer

In the emerging field of nanomedicine, nanoparticles have been widely considered as drug carriers and are now used in various clinically approved products. Therefore, in this study, we synthesized superparamagnetic iron-oxide nanoparticles (SPIONs) via green chemistry, and the SPIONs were further coated with tamoxifen-conjugated bovine serum albumin (BSA-SPIONs-TMX). The BSA-SPIONs-TMX were within the nanometric hydrodynamic size (117 ± 4 nm), with a small poly dispersity index (0.28 ± 0.02) and zeta potential of -30.2 ± 0.09 mV. FTIR, DSC, X-RD, and elemental analysis confirmed that BSA-SPIONs-TMX were successfully prepared. The saturation magnetization (M_s) of BSA-SPIONs-TMX was found to be ~8.31 emu/g, indicating that BSA-SPIONs-TMX possess superparamagnetic properties for theragnostic applications. In addition, BSA-SPIONs-TMX were efficiently internalized into breast cancer cell lines (MCF-7 and T47D) and were effective in reducing cell proliferation of breast cancer cells, with IC₅₀ values of 4.97 ± 0.42 μM and 6.29 ± 0.21 μM in MCF-7 and T47D cells, respectively. Furthermore, an acute toxicity study on rats confirmed that these BSA-SPIONs-TMX are safe for use in drug delivery systems. In conclusion, green synthesized superparamagnetic iron-oxide nanoparticles have the potential to be used as drug delivery carriers and may also have diagnostic applications.

miRacle of microRNA-Driven Cancer Nanotherapeutics

MicroRNAs (miRNAs) are non-protein-coding RNA molecules 20-25 nucleotides in length that can suppress the expression of genes involved in numerous physiological processes in cells. Accumulating evidence has shown that dysregulation of miRNA expression is related to the pathogenesis of various human diseases and cancers. Thus, stragegies involving either restoring the expression of tumor suppressor miRNAs or inhibiting overexpressed oncogenic miRNAs hold potential for targeted cancer therapies. However, delivery of miRNAs to tumor tissues is a challenging task. Recent advances in nanotechnology have enabled successful tumor-targeted delivery of miRNA therapeutics through newly designed nanoparticle-based carrier systems. As a result, miRNA therapeutics have entered human clinical trials with promising results, and they are expected to accelerate the transition of miRNAs from the bench to the bedside in the next decade. Here, we present recent perspectives and the newest developments, describing several engineered natural and synthetic novel miRNA nanocarrier formulations and their key in vivo applications and clinical trials.

Preparation Optimization of Bovine Serum Albumin Nanoparticles and Its Application for siRNA Delivery

BACKGROUND

siRNA brings hope for cancer therapy. However, there are many obstacles for application of siRNA in clinical. Because of the excellent biocompatibility, non-toxicity and non-immunogenicity of bovine serum albumin (BSA), BSA-based nanoparticles have been widely designed as a drug carrier system.

METHODS

The optimal formula for BSA NPs preparation was investigated by central composite design response surface methodology (CCD-RSM), BSA-based survivin-siRNA delivery system (BSA NPs/siRNA) was characterized by dynamic light scattering, atomic force microscope, transmission electron microscope and Bradford method. The in vitro anti-tumor effect and mechanism of BSA NPs were investigated by confocal microscopic imaging, MTT assay, RT-qPCR and ELISA analysis. Moreover, the anti-tumor effect, distribution and biosafety of BSA NPs were studied in vivo.

RESULTS

The optimal formula for BSA NPs was settled to be 20 mg/mL for BSA concentration, 9 for pH value, 136% for crosslinking degree and 1.6 mL/min for speed of ethanol addition. BSA NPs/siRNA could remain stable at 4°C for 4 weeks and protect siRNA from degradation by RNase A. Besides, BSA NPs/siRNA could maintain a sustained release of siRNA and promote the uptake of siRNA significantly. The survivin-mRNA level and the survivin-protein level were decreased by 55% ± 1.6% and 54% ± 1.6% separately. The in vivo tumor inhibition results suggested that the tumor inhibition rate of BSA NPs/siRNA-treated group was 54% ± 12% and was similar with that of DOX-treated group (57% ± 9.2%, P > 0.05). The biosafety results confirmed that BSA NPs/siRNA could not induce significant damages to the main organs and blood in vivo.

CONCLUSION

These results demonstrated that CCD-RSM was an effective tool for preparation analysis, and the BSA NPs/siRNA was a promising system for siRNA-based gene therapy.

Interaction pattern and in vitro, in vivo release behavior of simvastatin-loaded chitosan nanoformulation

Objective and methods: This study predicted the nature of chitosan interactions and effects of this interaction on drug release mechanism in simvastatin-loaded chitosan nanoformulation using molecular docking, spectroscopic and thermal analysis. Significance: This work explains in depth the molecular mechanism of simvastatin and chitosan bond formation in nanoformulation. Results: The effective encapsulation and sustain release properties of chitosan were indicated by increase in melting endotherm of simvastatin. Intermolecular hydrogen bond between third hydroxyl group pyranone ring of simvastatin and amino group of chitosan represented the stability of active lactone moiety that was not cleaved during formulation which is prerequisite for biological activity. UV-vis spectroscopic characterization, shift in infrared vibration wavenumber of simvastatin and chitosan, ligand titration, 1HNMR and 13C-NMR analyses confirmed this interaction pattern. The pharmacokinetic evaluation in mouse model revealed the sustain release property of nanoformulation. Conclusion: Thus formation of intermolecular hydrogen bond in nanoformulation contributed to modified physicochemical properties and improved in vivo performance of simvastatin.

Development and Characterization of Florfenicol-Loaded BSA Nanoparticles as Controlled Release Carrier

Florfenicol (FLO) is a broad-spectrum fluorinated antibiotic used for the treatment of bacterial diseases such as bovine respiratory disease (BRD) in cattle. FLO is a poorly soluble drug in aqueous solution, and its encapsulation in various nanovehicles has been reported to be less than 30%. In this context, the use of bovine serum albumin (BSA) as a nanocarrier for FLO is an interesting approach. BSA is a biocompatible, biodegradable, nontoxic, and nonimmunogenic natural protein, allowing the vehiculization of hydrophilic and hydrophobic drugs with a well-tolerated administration. The present work focuses on the fabrication and characterization of florfenicol-loaded BSA (FLO-BSA NPs), incorporation efficiency, and in vitro release pattern. FLO-BSA NPs nanoparticles were successfully obtained by a simple, low-cost and in a few steps method. The physicochemical properties of the obtained nanoparticles such as size (~ 120 nm), polydispersity index (0.04), and zeta potential (approximately - 40 mV) suggest a high colloidal stability and suitable characteristics for drug delivery. The drug loading reveals a high incorporation of florfenicol in the nanoparticles, in which 33.6 molecules of FLO are encapsulated per each molecule of BSA. The in vitro release profile exhibits an initial stage characterized by the burst effect and then a prolonged release of FLO from the albumin matrix, which is compatible with the Higuchi model and which follows a Fickian diffusion. The results together suggest a suitable tool for future investigations in drug delivery field in order to use this nanomaterial in food, pharmaceutical, and veterinary industry.

Pulmonary Administration of Microparticulate Antisense Oligonucleotide (ASO) for the Treatment of Lung Inflammation

Targeted delivery to the lung for controlling lung inflammation is an area that we have explored in this study. The purpose was to use microparticles containing an antisense oligonucleotide (ASO) to NF-κB to inhibit the production of proinflammatory cytokines. Microparticles were prepared using the B-290 Buchi Spray Dryer using albumin as the microparticle matrix. Physicochemical characterization of the microparticles showed the size ranged from 2 to 5 μm, the charge was - 38.4 mV, and they had a sustained release profile over 72 h. Uptake of FITC-labeled ASO-loaded microparticles versus FITC-labeled ASO solution by RAW264.7 murine macrophage cells was 5-10-fold higher. After pulmonary delivery of microparticles to Sprague-Dawley rats, the microparticles were uniformly distributed throughout the lung and were retained in the lungs until 48 h. Serum cytokine (TNF-α and IL-1β) levels of rats after induction of lung inflammation by lipopolysaccharide were measured until 72 h. Animals receiving ASO-loaded microparticles were successful in significantly controlling lung inflammation during this period as compared to animals receiving no treatment. This study was successful in proving that microparticulate ASO therapy was capable of controlling lung inflammation.

Redox responsive albumin autogenic nanoparticles for the delivery of cancer drugs

The present study explores preparation and characterization of redox sensitive albumin autogenic nanoparticles (ANPs) for drug delivery applications. Human serum albumin nanoparticles are prepared by desolvation method. The particles are stabilized through self-crosslinking and no external stabilizers are involved in the preparation. ANPs are then subjected to Camptothecin (CPT) drug loading. Experiments on in vitro and in vivo release profile, cytotoxic and cytocompatability, hemocompatability, blood clearance, tracking and bio imaging are studied in detail. The redox sensitive and drug release properties of ANPs studied in the presence of glutathione. Results on the physical, chemical and instrumental characterization warrant the property of the nanoparticles. ANPs obtained in the present study is biocompatible, biodegradable, effectively entangle the chosen drug, release the drug in the controlled manner, sensitive to reducing environment, nil toxicity and appreciable uptake by cells. In the current scenario on the requirement of a drug carrier with redox sensitive property to encounter cancer cells, the results of the present study on albumin nanoparticles with redox sensitivity is smart and pave the way in the cancer therapeutics.

Solid nano-in-nanoparticles for potential delivery of siRNA

siRNA-based therapeutics possess great potential to treat a wide variety of genetic disorders. However, they suffer from low cellular uptake and short half-lives in blood circulation; issues that remain to be addressed. This work is, to the best of our knowledge, the first to report the production of solid nano-in-nanoparticles, termed double nano carriers (DNCs) by means of the innovative technology of nano spray drying. DNCs (with a median size of 580-770nm) were produced by spraying at low temperatures (50°C) to prevent damage to heat-sensitive biomacromolecules like siRNA. DNCs consisting of Poly (d,l-lactide-co-glycolide) used as a wall material, encapsulating 20% human serum albumin primary nanoparticles (PNPs) loaded with siRNA, were obtained as a dry nanoparticulate powder with smooth spherical surfaces and a unique inner morphology. Incubation of pegylated or non-pegylated DNCs under sink conditions at 37°C, elicited a controlled release profile of the siRNA for up to 12 or 24h, respectively, with a minimal burst effect. Prolonged incubation of pegylated DNCs loaded with active siRNA (anti EGFR) in an A549 epithelial cell culture monolayer did not induce any apparent cytotoxicity. A slow degradation of the internalized DNCs by the cells was also observed resulting in the progressive release of the siRNA for up to 6days, as corroborated by laser confocal microscopy. The structural integrity and silencing activity of the double encapsulated siRNA were fully preserved, as demonstrated by HPLC, gel electrophoresis, and potent RNAi activity of siRNA extracted from DNCs. These results demonstrate the potential use of DNCs as a nano drug delivery system for systemic administration and controlled release of siRNA and potentially other sensitive bioactive macromolecules.

Antisense oligonucleotide delivery to cancer cell lines for the treatment of different cancer types

Amphiphilic poly(3-hydroxylalkanoate) (PHA) copolymers find interesting applications in drug delivery. The aim of this study was to prepare nucleic acid adsorbed on (PHB-b-PEG-NH₂) nanoparticle platform for gene delivery. For this purpose, PHB-b-PEG-NH₂ block copolymers were synthesized via transesterification reactions. The copolymers obtained were characterized by Proton Nuclear Magnetic Resonance (¹H-NMR), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) techniques. The cytotoxic, apoptotic and necrotic effects of these nanoparticles in the MDA 231 human breast cancer cell, the A549 human lung cancer cell and the L929 fibroblast cell lines were also investigated.

Single-Cell Isolation and Gene Analysis: Pitfalls and Possibilities

During the last two decades single-cell analysis (SCA) has revealed extensive phenotypic differences within homogenous cell populations. These phenotypic differences are reflected in the stochastic nature of gene regulation, which is often masked by qualitatively and quantitatively averaging in whole tissue analyses. The ability to isolate transcripts and investigate how genes are regulated at the single cell level requires highly sensitive and refined methods. This paper reviews different strategies currently used for SCA, including harvesting, reverse transcription, and amplification of the RNA, followed by methods for transcript quantification. The review provides the historical background to SCA, discusses limitations, and current and future possibilities in this exciting field of research.

Albumin nanoparticles coated with polysorbate 80 as a novel drug carrier for the delivery of antiretroviral drug-Efavirenz

Purpose of the study:

The antiretroviral therapy (ART) has dramatically improved human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) treatment, prevention and also has been found to increase the lifespan of HIV/AIDS patients by providing durable control of the HIV replication in patients. Efavirenz is a non-nucleoside reverse transcriptase inhibitor of HIV-1. The purpose of this study is to formulate efavirenz-loaded bovine serum albumin nanoparticles to improve efavirenz delivery into various organs.

Materials and Methods:

Nanoparticles were prepared by desolvation technique and coated with polysorbate 80. Ethanol, glutaraldehyde, and mannitol were used as desolvating, cross linking agent, and cryoprotectant, respectively. Drug to polymer ratio was chosen at five levels from 1:2, 1:3, 1:4, 1:5, and 1:6 (by weight). The formulated nanoparticles were characterized for Fourier Transform Infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) studies, entrapment efficiency, particle size, surface charge, surface morphology, in vitro drug release, release kinetics, stability studies, and biodistribution studies.

Results and Major Conclusion:

The particle size of the prepared formulations was found below 250nm with narrow size distribution, spherical in shape and showed good entrapment efficiency (45.62-72.49%). The in vitro drug release indicated biphasic release and its data were fitted to release kinetics models and release pattern was Fickian diffusion controlled release profile. The prepared nanoparticles increased efavirenz delivery into various organs by several fold in comparison with the free drug.

Mannosylated chitosan nanoparticles for delivery of antisense oligonucleotides for macrophage targeting

The therapeutic potential of antisense oligonucleotides (ASODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study focuses on designing mannosylated low molecular weight (LMW) chitosan nanoconstructs for safe ODNs delivery by macrophage targeting. Mannose groups were coupled with LMW chitosan and characterized spectroscopically. Mannosylated chitosan ODN nanoparticles (MCHODN NPs) were formulated by self-assembled method using various N/P ratio (moles of amine groups of MCH to phosphate moieties of ODNs) and characterized for gel retardation assay, physicochemical characteristics, cytotoxicity and transfection efficiency, and antisense assay. Complete complexation of MCH/ODN was achieved at charge ratio of 1:1 and above. On increasing the N/P ratio of MCH/ODN, particle size of the NPs decreased whereas zeta potential (ZV) increased. MCHODN NPs displayed much higher transfection efficiency into Raw 264.7 cells (bears mannose receptors) than Hela cells and no significant toxicity was observed at all MCH concentrations. Antisense assay revealed that reduction in lipopolysaccharide (LPS) induced serum TNF-α is due to antisense activity of TJU-2755 ODN (sequence complementary to 3′-UTR of TNF-α). These results suggest that MCHODN NPs are acceptable choice to improve transfection efficiency in vitro and in vivo.

The effect of antisense to NF-κB in an albumin microsphere formulation on the progression of left-ventricular remodeling associated with chronic volume overload in rats

BACKGROUND

Increased NF-κB levels play a crucial role in the pathophysiology of heart failure and are known to cause ventricular remodeling. Antisense therapy can be used for blocking the expression of NF-κB and subsequently avoiding heart failure. However, as with most biotechnology products, molecular instability and overall cost are often the major issues and concerns limiting the advancement of most antisense drugs to the market. Therefore, a cost-efficient biodegradable sustained release particle drug delivery system to transport and target NF-kB antisense to its intended site of action would be ideal.

PURPOSE

To evaluate the in vivo performance of a sustained release spray-dried albumin microsphere formulation for effective delivery and treatment of left ventricular remodeling with antisense to NF-κB.

METHODS

Albumin-based microspheres encapsulating antisense to NF-kB were prepared by spray drying and studied in a rat model to treat congestive heart failure.

RESULTS

The NF-κB activation and TNF-α release seen in treated animals were significantly lower than control animals. Ventricular remodeling was controlled in animals with antisense-treated AV fistulas as ΔV0-25 and ΔV0 were significantly lower compared to animals with untreated AV fistulas.

CONCLUSION

This treatment was successful in curbing ventricular remodeling by suppressing NF-κB activation.

Feasibility of haloperidol-anchored albumin nanoparticles loaded with doxorubicin as dry powder inhaler for pulmonary delivery

Haloperidol (Hal) is a ligand that can target sigma 2 receptors over-expressed in non-small cell lung cancer. Hal targeted nanoparticles of bovine serum albumin (BSA) were prepared for pulmonary delivery of doxorubicin (DOX). The conjugation was confirmed by Fourier transform infrared spectroscopy (FTIR) and (1)H nuclear magnetic resonance ((1)H NMR) spectroscopic methods. Nanoparticles were prepared by desolvation method from BSA-Hal and were loaded with DOX. They were characterized for their morphology, particle size, zeta potential, drug loading and release efficiency. The optimized nanoparticles were spray-dried using trehalose, l-leucin and mannitol as dry powder inhaler (DPI) in different inlet temperatures between 80 and 120°C. The obtained nanocomposites were characterized for their aerodynamic diameter, specific surface area (cm(2)/g) and fine particle fraction (FPF) by a Cascade Impactor device. The optimized nanoparticles showed particle size of 218 nm, zeta potential of -25.4 mV, drug entrapment efficiency of 89% and release efficiency of 56% until 2 h. After spray drying of these nanoparticles, the best results were obtained from mannitol with an inlet temperature of 80°C which produced a mean aerodynamic diameter of 4.58 μm, FPF of 66% and specific surface area of 6302.99 cm(2)/g. The obtained results suggest that the designed DPI could be a suitable inhaler for targeted delivery of DOX in pulmonary delivery.

Direct cell lysis for single-cell gene expression profiling

The interest to analyze single and few cell samples is rapidly increasing. Numerous extraction protocols to purify nucleic acids are available, but most of them compromise severely on yield to remove contaminants and are therefore not suitable for the analysis of samples containing small numbers of transcripts only. Here, we evaluate 17 direct cell lysis protocols for transcript yield and compatibility with downstream reverse transcription quantitative real-time PCR. Four endogenously expressed genes are assayed together with RNA and DNA spikes in the samples. We found bovine serum albumin (BSA) to be the best lysis agent, resulting in efficient cell lysis, high RNA stability, and enhanced reverse transcription efficiency. Furthermore, we found direct cell lysis with BSA superior to standard column based extraction methods, when analyzing from 1 up to 512 mammalian cells. In conclusion, direct cell lysis protocols based on BSA can be applied with most cell collection methods and are compatible with most analytical workflows to analyze single-cells as well as samples composed of small numbers of cells.

Ultrasound-targeted transfection of tissue-type plasminogen activator gene carried by albumin nanoparticles to dog myocardium to prevent thrombosis after heart mechanical valve replacement

Background

There are more than 300,000 prosthetic heart valve replacements each year worldwide. These patients are faced with a higher risk of thromboembolic events after heart valve surgery and long-term or even life-long anticoagulative and antiplatelet therapies are necessary. Some severe complications such as hemorrhaging or rebound thrombosis can occur when the therapy ceases. Tissue-type plasminogen activator (t-PA) is a thrombolytic agent. One of the best strategies is gene therapy, which offers a local high expression of t-PA over a prolonged time period to avoid both systemic hemorrhaging and local rebound thrombosis. There are some issues with t-PA that need to be addressed: currently, there is no up-to-date report on how the t-PA gene targets the heart in vivo and the gene vector for t-PA needs to be determined.

Aims

To fabricate an albumin nano-t-PA gene ultrasound-targeted agent and investigate its targeting effect on prevention of thrombosis after heart mechanic valve replacement under therapeutic ultrasound.

Methods

A dog model of mechanical tricuspid valve replacement was constructed. A highly expressive t-PA gene plasmid was constructed and packaged by nanoparticles prepared with bovine serum albumin. This nanopackaged t-PA gene plasmid was further cross-linked to ultrasonic microbubbles prepared with sucrose and bovine serum albumin to form the ultrasonic-targeted agent for t-PA gene transfection. The agent was given intravenously followed by a therapeutic ultrasound treatment (1 MHz, 1.5 w/cm², 10 minutes) of the heart soon after valve replacement had been performed. The expression of t-PA in myocardium was detected with multiclonal antibodies to t-PA by the indirect immunohistochemical method. Venous blood t-PA and D-dimer contents were tested before and 1, 2, 4, and 8 weeks after the operation.

Results

The high expression of t-PA could be seen in myocardium with increases in blood t-PA and D-dimer contents and thrombosis was prevented 8 weeks after operation.

Conclusion

We successfully fabricated an albumin nano-t-PA gene ultrasound-targeted agent that could prevent dog thrombosis after mechanical heart valve replacement. Our study provides an experimental basis for prevention of human thrombosis-related diseases.

Tamoxifen-loaded thiolated alginate-albumin nanoparticles as antitumoral drug delivery systems

Nanoparticles based on disulfide bond reduced bovine serum albumin and thiolated alginate (alginate-cysteine conjugate) have been prepared by coacervation method and have been loaded with tamoxifen (TMX). The TMX load into the nanoparticles was optimized (4-6 μg/mg NP) by freeze-drying the systems before the loading procedure. Maximum TMX release (45-52%) took place between 2 and 25 h. Cytotoxicity of unloaded nanoparticles in MCF-7 and HeLa cells was not observed, although a small decrease in viability took place at very high concentration. Cell uptake of nanoparticles occurred in both cell types and the presence of polysaccharide in the nanoparticle composition allowed a better interaction with cells. The administration of 10 μM TMX by TMX-nanoparticles was effective in both cellular lines, and the effect of the drug-loaded systems on MCF-7 cell cycle showed the efficacy of the TMX-loaded nanoparticles.

Encapsulation of hydrophobic aroma in whey protein nanoparticles

Aroma-loaded nanoparticles (d < 300 nm) were prepared by cross-linking denatured whey protein through pH-cycling. The effect of nanoparticulation conditions and aroma concentration on the physicochemical characteristics of nanoparticles and aroma release profile was studied. Better retention of aroma was observed when ethyl hexanoate was added before nanoparticle formation. The highest aroma retention was obtained for nanoparticles produced at pH 5.0 and 5.5 without calcium addition. These nanoparticles are characterized by a less compact and more porous internal structure allowing a higher loading of aroma. Increasing aroma concentration increased the diameter and the voluminosity of the aroma-loaded nanoparticles. The percentage of aroma retention showed an increase from 7% to 24% over the tested concentration range while the value averaged 2% for native or denatured whey protein. Encapsulation of ethyl hexanoate in whey protein nanoparticles reduced the mass transfer of aroma at the surface of the matrix and improved its retention.

Albumin-based nanoparticles as potential controlled release drug delivery systems

Albumin, a versatile protein carrier for drug delivery, has been shown to be nontoxic, non-immunogenic, biocompatible and biodegradable. Therefore, it is ideal material to fabricate nanoparticles for drug delivery. Albumin nanoparticles have gained considerable attention owing to their high binding capacity of various drugs and being well tolerated without any serious side-effects. The current review embodies an in-depth discussion of albumin nanoparticles with respect to types, formulation aspects, major outcomes of in vitro and in vivo investigations as well as site-specific drug targeting using various ligands modifying the surface of albumin nanoparticles with special insights to the field of oncology. Specialized nanotechnological techniques like desolvation, emulsification, thermal gelation and recently nano-spray drying, nab-technology and self-assembly that have been investigated for fabrication of albumin nanoparticles, are also discussed. Nanocomplexes of albumin with other components in the area of drug delivery are also included in this review.

Solid lipid nanoparticles loaded with anti-microRNA oligonucleotides (AMOs) for suppression of microRNA-21 functions in human lung cancer cells

PURPOSE

Literature has highlighted the practical use of solid lipid nanoparticles (SLNs) in research, but few reports have combined SLNs with miRNA-based therapy. We aimed to prepare SLNs to load anti-miRNA oligonucleotide (AMO) for miRNA-based therapy in vitro.

METHODS

SLNs were employed to encapsulate AMO by a solvent diffusion method, and then the properties of AMO-CLOSs (cationic lipid binded oligonucleotide (AMO)-loaded SLNs) were characterized. We studied cellular uptake and activation properties of AMO-CLOSs in A549 cells, including antisense efficiency, cell migration and invasion.

RESULTS

AMO-CLOSs were 187 nm in size and 46.6 mV in zeta potential with an approximately toroid morphology in the TEM image. AMO-CLOSs uptake by A549 cells was increased significantly higher and more effective than free AMO. Further results demonstrated that AMO-CLOSs showed high antisense efficiency of microRNA-21 and subsequently decreased the proliferation, migration and invasion of tumor cells.

CONCLUSIONS

These findings suggest that AMO-CLOSs represent a potential new approach for carrying anti-miRNA inhibitors for cancer therapy.

Triggered release of therapeutic antibodies from nanodiamond complexes

Recent reports have revealed that detonation nanodiamonds (NDs) can serve as efficient, biocompatible, and versatile drug delivery platforms. Consequently, further investigations exploring additional therapeutic applications are warranted. Current limitations associated with the non-specific nature of intravenous drugs limit the potential of certain pharmacological agents. One such treatment that could benefit from a stable delivery platform is antibody (Ab) therapy. Determination of Ab adsorption and desorption to a ND surface was subsequently examined using the transforming growth factor β (TGF-β) antibody as a model therapeutic. ND-Ab complexes were found to be stable in water through enzyme-linked immunosorbent assays (ELISAs), UV-vis spectroscopy and TEM, with no Ab released after ten days. Released Abs were detected in extreme pH solutions (3.5), DMEM (+) serum with pH levels ranging from 4 to 10.5, and inorganic saline solutions. Preserved activity of Abs released in DMEM (+) serum was confirmed using an ELISA. These results suggest ND-Ab complexes are synthesized and stabilized in water and are triggered to release active Abs upon exposure to physiological conditions.

Design and characterization of protein-quercetin bioactive nanoparticles

Background

The synthesis of bioactive nanoparticles with precise molecular level control is a major challenge in bionanotechnology. Understanding the nature of the interactions between the active components and transport biomaterials is thus essential for the rational formulation of bio-nanocarriers. The current study presents a single molecule of bovine serum albumin (BSA), lysozyme (Lys), or myoglobin (Mb) used to load hydrophobic drugs such as quercetin (Q) and other flavonoids.

Results

Induced by dimethyl sulfoxide (DMSO), BSA, Lys, and Mb formed spherical nanocarriers with sizes less than 70 nm. After loading Q, the size was further reduced by 30%. The adsorption of Q on protein is mainly hydrophobic, and is related to the synergy of Trp residues with the molecular environment of the proteins. Seven Q molecules could be entrapped by one Lys molecule, 9 by one Mb, and 11 by one BSA. The controlled releasing measurements indicate that these bioactive nanoparticles have long-term antioxidant protection effects on the activity of Q in both acidic and neutral conditions. The antioxidant activity evaluation indicates that the activity of Q is not hindered by the formation of protein nanoparticles. Other flavonoids, such as kaempferol and rutin, were also investigated.

Conclusions

BSA exhibits the most remarkable abilities of loading, controlled release, and antioxidant protection of active drugs, indicating that such type of bionanoparticles is very promising in the field of bionanotechnology.

Anticancer activity and molecular mechanism of resveratrol-bovine serum albumin nanoparticles on subcutaneously implanted human primary ovarian carcinoma cells in nude mice

This study investigates the antitumor effects and functional mechanism of resveratrol-bovine serum albumin nanoparticles (RES-BSANP) on human primary ovarian carcinoma cells in nude mice. An implanted tumor model was established by injecting a suspension of the human primary ovarian cancer cell SKOV(3) into the subcutaneous tissue of nude mice. The tumor-bearing mice (n = 32) were randomly divided into 8 groups, which received intraperitoneal injections of normal saline (0.9%, 0.5 mL), BSA (1.5 mg/kg, 0.5 mL), or RES-BSANP or RES (200, 100, and 50 mg/kg, 0.5 mL), respectively, once a week for 4 weeks. The in vivo antitumor efficacy was evaluated by measurement of tumor volume, whereas morphological alterations were observed by transmission electron microscope (atomic force microscopy); TUNEL assays and immunoblotting for apoptotic and cell proliferation proteins were carried out to elucidate the possible mechanism. RES-BSANP was found to exhibit certain highly desirable characteristics such as innocuity, better dispersity, and water solubility; it affected the in vivo tissue/organ distribution of RES in a remarkable manner. The administration of RES-BSANP significantly retarded the growth of carcinomas in nude mice from the third week onwards, and the inhibition rate was markedly higher than in mice treated with RES (52.43% vs. 46.34%, p < 0.05), without causing weight loss (p > 0.05). Simultaneously, apoptotic and necrotic morphological characteristics were observed with electron microscopy in the tumor tissues of treated mice. TUNEL staining revealed that the tumors from RES-BSANP-treated mice exhibited a similar apoptotic index as RES control tumors. Western blot analysis of the protein expression profiles revealed that part of the mechanism may be mediated by triggering the release of cytochrome c from the intermembrane space and upregulating the expression of caspase-9 and caspase-3, suggesting that the mitochondrial apoptotic pathway was being activated.

Preparation of ultrasound microbubbles crosslinked to albumin nanoparticles packaged with tissue-type plasminogen activator gene plasmid and method of in vivo transfection

Aims

To observe the effect of constructed ultrasound microbubble crosslinked to albium nanoparticles packaged with tissue-type plasminogen activator (tPA) gene plasmid on the in vivo transfection.

Methods

The rabbits were chosen for all experiments. A highly expressive gene plasmid for tPA was constructed and packaged into a prepared nanoparticle with bovine serum albumin (BSA). This albium nanoparticle packaged with tPA gene plasmid was crosslinked to an ultrasound microbubble prepared with BSA and sucrose to form a nano-targeting vector system for tPA gene transfection. The transfection and effective expression of tPA in heart, liver, leg skeletal muscle and the cervical rib were detected with polyclonal antibodies to tPA using immunohistochemical method; the tPA level and D-dimer content of blood were also tested.

Results

The expression of tPA could be seen in the tissues mentioned above, with the increase in blood tPA level and D-dimer content from 0.20 ± 0.05 µg/L and 81.76 ± 9.84 µg/L before the operation, to the higher levels of 0.44 ± 0.05 µg/L and 669.28 ± 97.74 µg/L after transfection.

Conclusion

The nano-targeting vector system for tPA gene was contructed successfully. This provides a new theory and experimental method for the nano-targeted transgene.

Formulation and in vitro characterization of spray-dried antisense oligonucleotide to NF-kappaB encapsulated albumin microspheres

The aim of this study was to formulate and characterize microspheres containing antisense oligonucleotide to NF-kappaB using bovine serum albumin as the polymer matrix. Microspheres were prepared by spray-drying technique with 5, 10 and 15% drug loading. Glutaraldehyde was used as a cross-linking agent. The particle sizes ranged from 3-5 microm. Microspheres were smooth and spherical in shape, as determined by scanning electron microscopy (SEM). The yield of microspheres ranged from 70-75% and the encapsulation efficiencies were found to be in the range of 59-60%, as determined by a novel HPLC method. Zeta potential of the microspheres ranged between -39 to -53 mV, thus indicating good suspension stability in water. In-vitro release studies performed using phosphate buffer saline demonstrated extended drug release up to 72 h. Kinetic model fitting showed high correlation with the Higuchi model, suggesting that the drug release was primarily diffusion controlled.

Uptake of plasmid-loaded nanoparticles in breast cancer cells and effect on Plk1 expression

The development of nucleic acid-based drugs for cancer therapeutic application has shown promising results in the past. However the delivery of these drugs to target cells is one problem which remains to be resolved. Nanoparticles have been described as promising strategies to deliver drugs into target cells. Human serum albumin (HSA) nanoparticles conjugated to trastuzumab for a cell type-specific targeting of human epidermal growth factor receptor 2 (HER2)-overexpressing cells were developed with incorporated expression plasmids for small hairpin RNAs (shRNAs) targeting polo-like kinase 1 (Plk1). Plk1 is a promising target for such an approach because it is overexpressed in all known cancer types and is a negative prognostic factor. Receptor-mediated uptake of the trastuzumab-modified nanoparticles into HER2-positive cells could be observed leading to reduced Plk1 expression. Taken together, HSA nanoparticles represent promising tools to deliver expression plasmids for shRNAs into target cells and should be further evaluated with regard to a therapeutic application of RNA interference in cancer therapy.

Preparation of sub-100-nm β-lactoglobulin (BLG) nanoparticles

Sub-100-nm nanoparticles were prepared from beta-lactoglobulin (BLG) with a narrow size distribution by a desolvation method using glutaraldehyde for cross-linking. With pre-heating of the BLG solution to 60 degrees C and subsequent pH readjustment to 9.0, nanoparticles of 59 +/- 5 nm were obtained with improved uniformity. Bovine serum albumin (BSA) nanoparticles, prepared under similar conditions for comparison, were larger and less uniform. The half-width of 80% particle distribution was used to compare the uniformity of particle size distribution. The stability of the nanoparticles was investigated by degradation tests at neutral and acidic pHs with and without proteolytic enzymes, trypsin and pepsin. The degradation time, determined by a graphical approach, was used to compare the relative stabilities of BLG and BSA nanoparticles. The particles of BLG were more stable than those of BSA in acidic and neutral media with and without added enzymes.

Preparation of well-defined core-shell particles by Cu2+-mediated graft copolymerization of methyl methacrylate from bovine serum albumin

Small well-defined core-shell poly(methyl methacrylate)-bovine serum albumin (PMMA-BSA) particles have been prepared in a direct one-step graft copolymerization of MMA from BSA at 75 degrees C in water with a trace amount of Cu2+ (5 microM). Initially, BSA generates free radicals and acts as a multifunctional macroinitiator, which leads to the formation of an amphiphilic PMMA-BSA grafting copolymer. Such formed copolymer chains act as a polymeric stabilizer to promote further emulsion polymerization of MMA inside, resulting in surfactant-free stable core-shell particles, confirmed by a transmission electron microscopic (TEM) analysis. The PMMA-BSA copolymers as well as PMMA homopolymer inside the particles were isolated by Soxhlet extraction and characterized by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry (TG). The highest grafting efficiency was approximately 80%. Effects of the reaction temperature, the MMA/BSA ratio, and the concentrations of Cu2+ and BSA on such core-shell particle formation have been systematically studied. Due to their inert PMMA core and biocompatible BSA shell, these small polymer particles are potentially useful in biomedical applications.

Effect of trastuzumab-modified antisense oligonucleotide-loaded human serum albumin nanoparticles prepared by heat denaturation

Nanoparticles represent a promising tool for targeted drug delivery to tumour cells and are able to protect drugs against degradation. In our present study we developed targeted nanoparticles loaded with antisense oligonucleotides (ASOs) against Plk1 (polo-like kinase 1) prepared by heat denaturation instead of using glutaraldehyde. Glutaraldehyde can lead to an inactivation of ASOs through chemical crosslinking and is a toxic entity. We examined the ideal preparation conditions and characterised the resulting particles in terms of physico-chemical properties, ASO recovery after enzymatic degradation and stability. Stable monodisperse nanoparticles with an ASO recovery of more than 80% could be prepared at a temperature of 105 degrees C for 10 min. Furthermore we performed quantitative real-time PCR and Western blot to detect an ASO-mediated effect on Plk1 in BT-474 cells. We observed a significant reduction of Plk1 mRNA and protein expression. Thus, this is the first report of ASO-loaded HSA nanoparticles prepared by heat denaturation, where an impact on gene expression could be observed. The data provide the basis for the further development of carrier systems for ASOs to reduce off-target effects evoked by systemically administered ASOs and to achieve a better penetration into primary and metastatic target cells.

Recent developments in nanoparticle-based drug delivery and targeting systems with emphasis on protein-based nanoparticles

BACKGROUND

Drug delivery systems with nm dimensions (nanoparticles [NPs]) are attracting increasing attention because they can sequester drugs in systemic circulation, prevent non-specific biodistribution, and target to specific tissues.

OBJECTIVE

We reviewed the recent literature pertinent to NP-based drug delivery, primarily emphasizing NPs fabricated from proteins.

METHODS

A summary of common NP fabrication techniques is provided along with the range of sizes and functional properties obtained. The NP properties critical for injectable drug delivery are reviewed, as well as the attempts to design 'tissue-specific' NPs.

RESULTS/CONCLUSIONS

It has been possible to design > 100 nm NPs from different biomaterials, and further understanding of in vivo stability and interactions with physiologic systems will lead to improved drug delivery systems.

Micro/nanostructured polymeric systems for biomedical and pharmaceutical applications

This review provides an outline of the polymeric micro/nanostructured advanced systems that are suited for the controlled and targeted administration of, specifically, nonconventional drugs. The contribution of new trends in drug-delivery technology is focused on two major parts, dealing with brief surveys of: the biodegradable/bioerodible polymeric systems used in the formulation of micro/nanoparticles and techniques used in the preparation of micro/nanoparticles for their biomedical application in cancer treatment specifically, in inflammation pathologies, as oxygen carriers (blood substitutes) and in tissue-engineering practice. A small discussion of the future perspectives of the described systems is also given.