Characterization of novel lactoferrin loaded capsules prepared with polyelectrolyte complexes

Amelioration of Acute Alcoholic Liver Injury via Attenuating Oxidative Damage and Modulating Inflammation by Means of Ursodeoxycholic Acid-Zein Nanoparticles

Ursodeoxycholic acid (UDCA) has been broadly adopted for the clinical treatment of hepatic and biliary diseases; however, its poor water-solubility becomes an obstacle in wide applications. To overcome these challenges, herein, a two-tier UDCA-embedded system of zein nanoparticles (NPs) along with a polyelectrolyte complex was designed under facile conditions. Both the UDCA-zein NPs and their inclusion microcapsules showed a spherical shape with a uniform size. A typical wall plus capsule/core structure was formed in which UDCA-zein NPs distributed evenly in the interior. The UDCA inclusion microcapsules had an encapsulation rate of 67% and were released in a non-Fickian or anomalous transport manner. The bioavailability and efficacy of UDCA-zein NPs were assessed in vivo through the alcoholic liver disease (ALD) mouse model via intragastric administration. UDCA-zein NPs ameliorated the symptoms of ALD mice remarkably, which were mainly exerted through attenuation of antioxidant stress levels. Meanwhile, it notably upregulated the intestinal tight junction protein expression and improved and maintained the integrity of the mucosal barrier effectively. Collectively, with the improvement of bioavailability, the UDCA-zein NPs prominently alleviated the oxidative damage induced by alcohol, modulating the inflammation so as to restore ALD. It is anticipated that UDCA-zein NPs have great therapeutic potential as sustained-nanovesicles in ALD treatment.

Microencapsulation of functional ovalbumin and bovine serum albumin with polylysine-alginate complex for sustained protein vehicle's development

Overcoming harsh gastric environment is still a challenging to bioactive proteins, microencapsulation provides one strategy in designing this protection barrier. In this work, bovine serum albumin and ovalbumin were chosen as model proteins, while polylysine-alginate complex was fabricated for microencapsulation purpose. Both of the protein-loaded microcapsules had regular internal microstructures. The model protein's embedding increased the thermal stability of the microcapsules. Both of the protein-loaded microcapsules had a slow release rate in simulated gastric fluids (pH 3.0), while a sustained release profile in simulated intestinal fluids (pH 6.4), indicating an excellent tolerance to the acidic gastric environment. The microencapsulation process was mild and had no influence on the protein's molecular weight, while a slight peak shifting occurred in the secondary structure of the released proteins. The developed microcapsules could be explored as a kind of vehicle for bioactive proteins applied in functional foods, health care products and medical formulations.

Stability-Indicating Analytical Approach for Stability Evaluation of Lactoferrin

Lactoferrin is a multifunctional iron-binding glycoprotein in milk. Due to its potential for the treatment of various diseases, interest in products containing lactoferrin is increasing. However, as a protein, it is prone to degradation, which critically affects the quality of products. Therefore, the main purpose of our work was to develop a stability-indicating analytical approach for stability evaluation of lactoferrin. We were focused on two complementary methods: reversed-phase and size-exclusion chromatography. The stability-indicating nature of the selected methods was confirmed. They were successfully validated by following the ICH guidelines and applied to preliminary lactoferrin stability studies. Up to three degradation products, as well as aggregates and fragments of lactoferrin, were detected in various samples using complementary reversed-phase and size-exclusion chromatographic methods. The analytical approach was additionally extended with three spectroscopic techniques (absorbance, intrinsic fluorescence, and bicinchoninic acid method), which may provide valuable complementary information in some cases. The presented analytical approach allows the stability evaluation of lactoferrin in various samples, including the ability to detect differences in its degradation mechanisms. Furthermore, it has the potential to be used for the quality control of products containing lactoferrin.

Oral fate and stabilization technologies of lactoferrin: a systematic review

Lactoferrin (Lf), a bioactive protein initially found in many biological secretions including milk, is regarded as the nutritional supplement or therapeutic ligand due to its multiple functions. Research on its mode of action reveals that intact Lf or its active peptide (i.e., lactoferricin) shows an important multifunctional performance. Oral delivery is considered as the most convenient administration route for this bioactive protein. Unfortunately, Lf is sensitive to the gastrointestinal (GI) physicochemical stresses and lactoferricin is undetectable in GI digesta. This review introduces the functionality of Lf at the molecular level and its degradation behavior in GI tract is discussed in detail. Subsequently, the absorption and transport of Lf from intestine into the blood circulation, which is pivotal to its health promoting effects in various tissues, and some assisting labeling methods are discussed. Stabilization technologies aiming at preserving the structural integrity and functional properties of orally administrated Lf are summarized and compared. Altogether, this work comprehensively reviews the structure-function relationship of Lf, its oral fate and the development of stabilization technologies for the enhancement of the oral bioavailability of Lf. The existing limitations and scope for future research are also discussed.

Development of metformin hydrochloride loaded dissolving tablets with novel carboxymethylcellulose/poly-l-lysine/TPP complex

Natural polymers like polysaccharides, polypeptides and their derivatives are broadly applied in drug delivery due to excellent biocompatibility and biodegradability. In this study, the dissolving tablets, formed with carboxymethylcellulose/poly-l-lysine/tripolyphosphate (CMC/PLL/TPP) complex, were prepared using metformin hydrochloride (MetHCl) as model drug. Confocal laser scanning microscopy observation manifested that FITC-labeled PLL interacted with CMC and formed a uniform interior microstructure. Scanning electron microscope images showed the drug-loaded tablets had well-formed shapes with smooth surfaces. MetHCl embedded interior the microstructures of the tablets and represented in a crystal form. Thermo-gravimetric analysis and differential scanning calorimetry indicated that the drug-loaded tablets had stable thermal properties with less moisture content (3.52%). Fourier transform infrared spectrometer confirmed that the CMC/PLL/TPP complex was fabricated via the electrostatic interactions between -NH₃⁺, -COO^- and -[P₂O₅⁴-]^- groups. The drug-loaded tablets had a high drug loading efficiency of 85.76% and drug encapsulation efficiency of 81.47%, and a shorter wetting time of 2.16 min in SSF (pH 6.8) and lower swelling ratio of 233.34%. The drug loaded in the samples could be released completely within 10 min in simulated saliva fluid (SSF pH 6.8), indicating a rapid drug release and dissolving profile in the environment, which could be developed for dissolving tablets.

E-Jet 3D-Printed Scaffolds as Sustained Multi-Drug Delivery Vehicles in Breast Cancer Therapy

PURPOSE

Combination chemotherapy is gradually receiving more attention because of its potential synergistic effect and reduced drug doses in clinical application. However, how to precisely control drug release dose and time using vehicles remains a challenge. This work developed an efficient drug delivery system to combat breast cancer, which can enhance drug effects despite reducing its concentration.

METHODS

Controlled-release poly-lactic-co-glycolic acid (PLGA) scaffolds were fabricated by E-jet 3D printing to deliver doxorubicin (DOX) and cisplatin (CDDP) simultaneously.

RESULTS

This drug delivery system allowed the use of a reduced drug dosage resulting in a better effect on the human breast cancer cell apoptosis and inhibiting tumor growth, compared with the effect of each drug and the two drugs administrated without PLGA scaffolds. Our study suggested that DOX-CDDP-PLGA scaffolds could efficiently destroy MDA-MB-231 cells and restrain tumor growth.

CONCLUSIONS

The 3D printed PLGA scaffolds with their time-programmed drug release might be useful as a new multi-drug delivery vehicle in cancer therapy, which has a potential advantage in a long term tumor cure and prevention of tumor recurrence.

Cellulose modification and shaping – a review

This review aims to present cellulose as a versatile resource for the production of a variety of materials, other than pulp and paper. These products include fibers, nonwovens, films, composites, and novel derivatized materials. This article will briefly introduce the structure of cellulose and some common cellulose derivatives, as well as the formation of cellulosic materials in the micro- and nanoscale range. The challenge with dissolution of cellulose will be discussed and both derivatizing and nonderivatizing solvents for cellulose will be described. The focus of the article is the critical discussion of different shaping processes to obtain a variety of cellulose products, from commercially available viscose fibers to advanced and functionalized materials still at the research level.

Preparation and Characterization of Protein-Loaded Electrospun Fiber Mat and Its Release Kinetics

For the enhancement of protein's bioavailability, a specific delivery system was developed by coaxial electrospinning. Bovine serum albumin (BSA) was used as protein model, and the core-sheath fiber mat was fabricated using sodium alginate as shell layer and the BSA-loaded chitosan nanoparticle that was prepared previously as core layer. By optimizing electrospinning parameters, uniform fibers with diameters ranging from 200-600 nm were obtained, and transmission electron microscopy and confocal laser scanning microscopy revealed their core-sheath structures. Fourier transform infrared spectroscopy (FTIR) analysis demonstrated that there existed molecular interaction between components, which enhanced the mat's thermal stability and mechanic property. It was found that the predominant release mechanism of BSA from fiber mat was erosion, and little change occurred in the secondary structure of encapsulated BSA indicated by FTIR and circular dichroism analysis. The study shows that the obtained fiber mat is a potential delivery system for protein.

Nanostructures for delivery of natural antimicrobials in food

Natural antimicrobial compounds are a topic of utmost interest in food science due to the increased demand for safe and high-quality foods with minimal processing. The use of nanostructures is an interesting alternative to protect and delivery antimicrobials in food, also providing controlled release of natural compounds such as bacteriocins and antimicrobial proteins, and also for delivery of plant derived antimicrobials. A diversity of nanostructures are capable of trapping natural antimicrobials maintaining the stability of substances that are frequently sensitive to food processing and storage conditions. This article provides an overview on natural antimicrobials incorporated in nanostructures, showing an effective antimicrobial activity on a diversity of food spoilage and pathogenic microorganisms.

Preparation, characterization, and in vitro/vivo studies of oleanolic acid-loaded lactoferrin nanoparticles

Oleanolic acid (OA), a pentacyclic triterpene, is used to safely and economically treat hepatopathy. However, OA, a Biopharmaceutics Classification System IV category drug, has low bioavailability owing to low solubility (<1 μg/mL) and biomembrane permeability. We developed a novel OA nanoparticle (OA-NP)-loaded lactoferrin (Lf) nanodelivery system with enhanced in vitro OA dissolution and improved oral absorption and bioavailability. The OA-NPs were prepared using NP albumin-bound technology and characterized using dynamic light scattering, scanning electron microscopy, X-ray powder diffraction, differential scanning calorimetry, and in vitro dissolution test. The in vivo pharmacokinetics was investigated in Sprague Dawley rats using liquid chromatography-tandem mass spectrometry. OA-NPs (OA:Lf =1:6, w/w%) exhibited spherical morphology, 202.2±8.3 nm particle size, +(27.1±0.32) mV ζ potential, 92.59%±3.24% encapsulation efficiency, and desirable in vitro release profiles. An effective in vivo bioavailability (340.59%) was achieved compared to the free drug following oral administration to rats. The Lf novel nanodelivery vehicle enhanced the dissolution rate, intestinal absorption, and bioavailability of OA. These results demonstrate that Lf NPs are a new strategy for improving oral absorption and bioavailability of poorly soluble and poorly absorbed drugs.

Self-assembled polyelectrolyte complexes films as efficient compression coating layers for controlled-releasing tablets

Currently, polysaccharide-based hydrogels are widely studied macromolecular networks to modify drug dissolution from controlled-releasing matrix tablets. Among them, polyelectrolyte complexes (PEC) films consisted of chitosan (CS) and sodium alginate (SA) could be obtained via spontaneously assembling under physiological gastrointestinal environment. Here, we utilized these self-assembled PEC films as an efficient coating materials to develop controlled-released matrix tablets through compression coating process, with paracetamol (APAP) as model drug. The constitutive and morphology characteristic studies on these PEC films illustrated that the mixture of CS and SA with the weight ratio of 1:1 would be an promising outer layer for compression-coating tablets. In addition, the in vitro drug releasing behavior experiments demonstrated that the optimized compression coating tablets displayed satisfied zero-order drug releasing profits. Furthermore, the in vivo pharmacokinetic studies of these APAP loaded compression-coated tablets in New Zealand rabbits gave that the T_max (12.32 ± 1.05 h) was significantly prolonged (p < 0.01), compared to that (0.89 ± 0.26 h) of common APAP tablets (Jinfuning^®) after oral administration. These studies suggest that the compression-coated tablets with self-assembled PEC film as coating outer layer may be a promising strategy for peroral controlled release delivery system of water soluble drugs.

Evaluation of chitosan hydrochloride-alginate as enteric micro-probiotic-carrier with dual protective barriers

In this study, the cells-free and cells-loaded chitosan hydrochloride-alginate (CHC-Alg) microcapsules were firstly fabricated with polyelectrolyte complexes via an orifice-polymerization method. Scanning electron microscope images showed that the CHC-Alg microcapsules had a typical shell-core structure and the model probiotic cells (Bacillus licheniformis) were embedded in the core in cells-loaded microcapsules. The microcapsules prepared had good thermal stability and moisture property (3.89%). Cells survival and release studies showed that the number of probiotic cells released from the cells-loaded microcapsules (approx. 6.36logCFUml^-1) was 6.19logCFUml^-1 when they were performed in the simulated gastric fluid (SGF, pH 2.0) for 1h and subsequently in the simulated intestinal fluid (SIF, 0.3%) for 4h. The CHC-Alg microcapsules with favorable swelling performances were helpful to permeate the harsh acid to protect the cells in the SGF (pH 2.0). The CHC-Alg microcapsules effectively protected the model probiotic cells, which was attributed to the "dual protective barriers" of the shell-core structure, that is, the primary barrier of the Alg hydrogel layer formed with a compact polymer matrix and the secondary barrier of the PEC film formed on the surface. The microcapsules prepared could be used as an enteric micro-probiotic-carrier for designing potential probiotic delivery systems.

Design of chitosan and its water soluble derivatives-based drug carriers with polyelectrolyte complexes

Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail.

Polyphosphates as inorganic polyelectrolytes interacting with oppositely charged ions, polymers and deposited on surfaces: fundamentals and applications

Polyphosphates are important but neglected polyelectrolytes that play a major role in biology and in surface science for the stabilization of colloids against flocculation and for the preservation of food. They are also known as "Calgon" ® and intensively used as additives in washing powders. This review aims to review recent developments in which linear polyphosphates are used for the design of new functional coatings using sol-gel processes and layer-by-layer deposition methods. All these methods rely on the high charge density of polyphosphates as inorganic polyelectrolytes, therefore the structure and properties of these molecules are also reviewed. New perspectives will also been given for the design of stimuli responsive coatings at the tiny frontier between biology and materials science.