Effect of beta glucan coating on controlled release, bioaccessibility, and absorption of ß-carotene from loaded liposomes.

Recently, the use of biopolymers as coating material to stabilise phospholipid-based nanocarriers has increased. One such class of biopolymers is the dietary fibre beta-glucan (ßG). In this study, we developed and characterized beta-carotene (ßC) loaded ßG coated nanoliposomes (GNLs) to investigate the effect of ßG coating on the stability, controlled release, bioaccessibility, diffusion and subsequent absorption of the lipophilic active agent. The size, charge (Z-potential), and FTIR spectra were measured to determine the physicochemical stability of GNLs. ßG coating reduced the bioaccessibility, provided prolonged release and improved the antioxidant activity of the nanoliposomes. Multiple particle tracking (MPT) data suggested that ßC-GNLs were less diffusive in porcine intestinal mucus (PIM). Additionally, the microviscosity of the PIM treated with GNLs was observed to be higher (0.04744 ± 0.00865 Pa s) than the PIM incubated with uncoated NLs (0.015 ± 0.0004 Pa s). An Ex vivo experiment was performed on mouse jejunum to measure the absorption of beta-carotene from coated (ßC-GNLs) and uncoated nanoliposomes (ßC-NLs). Data showed that after 2 hours, 27.7 ± 1.3 ng mL-1 of ßC encapsulated in GNLs and 61.54 ± 3 ng mL-1 of the ßC encapsulated in uncoated NLs was absorbed by mouse intestinal mucosa. These results highlight that coating with ßG stabilise NLs during gastrointestinal digestion and provides more sustained release of ßC from nanoliposomes.

Active Composite Packaging Reinforced with Nisin-Loaded Nano-Vesicles for Extended Shelf Life of Chicken Breast Filets and Cheese Slices.

To meet the demands for more effective and ecofriendly food packaging strategies, the potential of nisin-loaded rhamnolipid functionalized nanofillers (rhamnosomes) has been explored after embedding in hydroxypropyl-methylcellulose (HPMC) and κ-carrageenan (κ-CR)-based packaging films. It was observed that intrinsically active rhamnosomes based nanofillers greatly improved the mechanical and optical properties of nano-active packaging (NAP) films. Incorporation of rhamnosomes resulted in higher tensile strength (5.16 ± 0.06 MPa), Young's modulus (2777 ± 0.77 MPa), and elongation (2.58 ± 0.03%) for NAP than active packaging containing free nisin (2.96 ± 0.03 MPa, 1107 ± 0.67 MPa, 1.48 ± 0.06%, respectively). NAP demonstrated a homogenous distribution of nanofillers in the biopolymer matrix as elucidated by scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) confirmed that NAP prepared with nisin-loaded rhamnosomes was thermally stable even above 200 °C. Differential scanning calorimetry (DSC) analyses revealed that addition of nisin in nanofillers resulted in a slight increase in Tg (108.40 °C), indicating thermal stability of NAP. Fourier transform infrared spectroscopy (FTIR) revealed slight shift in all characteristic bands of nano-active packaging, which indicated the embedding of rhamnosomes inside the polymer network without any chemical interaction. Finally, when tested on chicken breast filets and cheese slices under refrigerated storage conditions, NAP demonstrated broad-spectrum antimicrobial activity (up to 4.5 log unit reduction) and inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. These results suggest that HPMC and κ-CR-based NAP containing functionalized nanofillers can serve as an innovative packaging material for the food industry to improve the safety, quality, and shelf-life of dairy and meat products. Supplementary Information: The online version contains supplementary material available at 10.1007/s11947-022-02815-2.

Improving carvacrol bioaccessibility using core-shell carrier-systems under simulated gastrointestinal digestion.

The impact of encapsulating carvacrol in chitosan-albumin based core-shell nano-carriers (NCs) on its stability and bioaccessibility was determined under simulated digestion conditions. These NCs consisted of chitosan (C) core enclosed by bovine serum albumin (BSA) shell. The mean particle size ranged from 52.4 ± 10 nm to 203 ± 6 nm and zeta-potential from + 21 ± 3.6 to -18 ± 2.7 mV. The size and charge were significantly modified after the protein-shell formation around the polysaccharide-core. Core-shell NCs were more stable, with less aggregation under simulated gastrointestinal conditions than C-NCs, presumably due to greater steric repulsion. Likewise, core-shell NCs were observed relatively more stabilized in the intestinal phase than gastric phase. The bioaccessibility of carvacrol was enhanced significantly when it was encapsulated in the core-shell NCs. These findings imply that C-BSA based core-shell NCs might be an efficient means of encapsulating, protecting and delivering hydrophobic bioactive compounds for applications in functional foods.

Impact of albumin corona on mucoadhesion and antimicrobial activity of carvacrol loaded chitosan nano-delivery systems under simulated gastro-intestinal conditions.

Emerging antibiotic resistance in pathogens has posed considerable challenges to explore and examine the natural antimicrobials (NAMs). Due to the labile nature of NAMs, nano-delivery systems (NDS) are required to protect them from physiological degradation and allow controlled delivery to the targeted site of infection. In this study, corona modified NDS were developed using bovine serum albumin (BSA) on a chitosan core (CS) for sustained delivery of carvacrol (CAR), a natural antimicrobial agent, in the intestine. The optimal nano-formulations of the core (CS-NDS) and corona modified (BSA-CS-NDS) systems were fabricated with an average diameter of 52.4 ± 10.4 nm and 202.6 ± 6 nm, respectively. A shift in zeta-potential (ZP) from positive (+21 ± 3.6 mV) to negative values (-18 ± 2.6 mV) confirmed the electrostatic deposition of BSA corona on CS core. Under the influence of various simulated gastrointestinal conditions, BSA corona provided extra stability to NDS (ZP -38.5 mV), by ensuring delayed release and limited degradation in the gastric conditions. Mucoadhesive studies with quartz crystal microbalance with dissipation (QCM-D) revealed that BSA corona reduced the mucoadhesion of NDS at gastric pH, which enabled the effective delivery of CAR to the intestinal phase for successful eradication of Salmonella enterica.

Alginate-caseinate based pH-responsive nano-coacervates to combat resistant bacterial biofilms in oral cavity.

Biofilm associated microbial resistance is a major concern in oral health and hygiene. Nano-antimicrobials (NAMs) having natural antibiotic replacers e.g. nisin are the possible solution to treat oral infections. In this study, we have developed pH responsive, mucoadhesive protein-polysaccharide [sodium caseinate (NaC)-sodium alginate (AL)] coacervate based nano-carrier systems (PPC-NCS) to prevent and eradicate oral biofilms associated pathogens e.g. Enterococcus faecium, Staphylococcus epidermidis and Enterococcus faecalis. PPC-NCS were formed at pH 5 with highest encapsulation efficiency of 75.1 ± 1.2%, then at pH 6 (31 ± 1.1%) and 7 (15 ± 2%). SEM of PPC-NCS displayed smooth and round morphology. Particle size of PPC-NCS was observed to be 244 nm by DLS, with negative zeta potential (-47 ± 4.31 mV). In FTIR analysis, merging of OH stretching peak of NaC (2889.53 cm-1) and CH stretching of AL (2920 cm-1) with appearance of a new peak at 2062 cm-1 was observed that confirmed covalent and hydrogen bonding between two compounds. Antimicrobial and antibiofilm assays demonstrated better control of nisin loaded PPC-NCS against selected pathogens, while preventing and eradicating bacterial biofilms successfully without any cytotoxic effect. These results recommend that coacervates based NAMs are suitable carriers for pH-triggered release of antimicrobials in the buccal cavity to control biofilm associated oral infections.

Chitosan-albumin based core shell-corona nano-antimicrobials to eradicate resistant gastric pathogen.

In this study, protein/polysaccharide core-shell-corona (PP-CSC) nano delivery systems (NDS) were prepared by using bovine serum albumin (BSA) and chitosan (CS). The potential of PP-CSC-NDS for increasing the stability and bio-accessibility of ε-poly-l-lysine (ε-PL) as effective therapy for gastric Helicobacter pylori was investigated. The presence of CS-shell increased the size (223 ±â€¯1.7 nm) of BSA-core as compared to BSA-shell on CS-core (191 ±â€¯2.6 nm). Conversely, encapsulation efficiency of ε-PL was reduced for C(B)NDS [CS-shell on BSA-core] to 73 ±â€¯1% than 82 ±â€¯2% for B(C)NDS [BSA-shell on CS-core] due to cationic nature of ε-PL. Scanning electron microscopy of PP-CSC-NDS displayed smooth and non-flocculated morphology. FTIR analyses verified that the electrostatic interactions, H-bonding, and hydrophobic effects were involved in PP-CSC formation. Zeta analyses revealed that the net charge depends on the corona layer and the encapsulated antimicrobials. Moreover, CS corona improved the antimicrobial potential, controlled release, mucoadhesion and stability of ε-PL loaded C(B)NDS in simulated gastric fluid due to inherent antimicrobial and mucoadhesive properties of CS polymer. In contrast, protein corona improved the penetration into bacterial biofilms for better eradiation of H. pylori. Thus, conjugated nano-systems with selected corona can improve the overall efficacy of antimicrobials to develop effective nano-therapeutics against gastric infections.

Prospectives of Antihypertensive Nano-ceuticals as Alternative Therapeutics.

BACKGROUND: Global death rate due to cardiovascular diseases (CVDs) is highest as compared to other ailments. Principal risk factor associated with CVDs is hypertension. Major classes of current antihypertensive (AHT) therapies include angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARBs) and calcium channel blockers (CCBs). All these antihypertensive therapeutic drugs have low oral bioavailability and can induce upper respiratory tract abstraction, angioedema, reflex tachycardia and extreme hypotensive effect after oral administration which can cause lethal effects in patients with heart diseases. OBJECTIVE: Controlled and targeted release by using antihypertensive nano-medicines can provide better solution to overcome above-mentioned side effects. RESULTS: Scientific evolution towards the development of biopolymer based nano-carrier systems has unlocked new horizons for safe and/or edible nano drug delivery systems. In this article, we have reviewed in detail various mechanisms of AHT drugs, major draw backs associated with current therapeutic strategies, and the advantages of AHT nano-medicines over conventional drugs. Furthermore, recent reports of bio-based nano/micro -carrier systems with different AHT drugs have been analyzed with their key features. In depth review has been presented for chitosan as a potential carrier of AHT drugs due to its distinctive properties comprising muco-adhesive attribute, permeation enhancement as well as its biocompatible and biodegradable nature. CONCLUSION: Chitosan based novel AHT nano-ceuticals can improve oral bioavailability, reduce hydrophobicity and increase the plasma half-life of AHT drugs by their sustained release in lower part of the GIT.

Polyelectrolyte Multicomponent Colloidosomes Loaded with Nisin Z for Enhanced Antimicrobial Activity against Foodborne Resistant Pathogens.

Food grade micro- or nano-carrier systems (NCS) are being developed to improve the controlled release of antimicrobial agents. To augment the stability of liposomal NCS and to overcome the limitations associated with the use of free bacteriocin (nisin) in the food system, multi-component colloidosomes (MCCS) were developed by electrostatic interactions between anionic alginate and cationic chitosan (multilayer) around phospholipids based liposomes (core). Zeta-sizer results revealed the average diameter of 145 ± 2 nm, 596 ± 3 nm, and 643 ± 5 nm for nano-liposome (NL), chitosomes (chitosan coated NL) and MCCS, respectively. Zeta potential values of NCS varied from -4.37 ± 0.16 mV to 33.3 ± 6 mV, thus both chitosomes (CS) and MCCS were positively charged. Microstructure analysis by scanning electron microscope (SEM) revealed relatively higher size of MCCS with smooth and round morphology. TGA and DSC based experiments revealed that MCCS were thermally more stable than uncoated liposomes. Encapsulation efficiency of nisin in MCCS was observed to be 82.9 ± 4.1%, which was significantly higher than NL (56.5 ± 2.5%). FTIR analyses confirmed the cross-linking between sodium alginate and chitosan layer. Both qualitative (growth kinetics) and quantitative (colony forming unit) antimicrobial assays revealed that nisin loaded MCCS have superior potential to control resistant foodborne pathogens including Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis, (5.8, 5.4, and 6.1 Log CFUmL-1 reduction, respectively) as compared to free nisin, loaded NL or CS. Controlled release kinetics data fitted with Korsmeyer-Peppas model suggested that nisin release from MCCS followed Fickian diffusion. Cytotoxic studies on human blood cells and HepG2 cell lines revealed hemocompatibility and non-toxicity of MCCS. Thus, due to enhanced controlled release, stability and biocompatibility; these multi-component colloidosomes can be useful for incorporating antimicrobial agents into functional foods, beverages and pharmaceutical products to combat pathogenic and spoilage bacteria.

Polyionic hybrid nano-engineered systems comprising alginate and chitosan for antihypertensive therapeutics.

Hydrophobic nature of virtually all antihypertensive (AHT) drugs is the major hindrance towards their oral administration. Current study focuses on the development of polyionic hybrid nano drug delivery systems comprising sodium alginate and chitosan, loaded with distinct AHT drugs (captopril, amlodipine and valsartan). Encapsulation efficiency of hybrid NCS increased in the order of amlodipine>valsartan>captopril with average value of 42±0.9%, 91±1.5% and 96±1.9%, respectively. Scanning electron microscopy revealed hybrid NCS with smooth topography and round appearance in case of captopril. FTIR analysis confirmed the cross-linking between amino and carboxylate group of chitosan and alginate to form polyionic structures at nano-scale. Zeta-sizer experiments revealed that particle size distribution had increased from 197±12nm to 341±15nm for void and captopril loaded NCS. However, highly positive zeta potential of +32±1.6mV was not decreased significantly. In vitro sustained release assays reflected excellent retention of AHT drug in hybrid nanoparticles at 4°C and 37°C in physiological buffer, as less than 8% of the total drug was released in first 24h. Thus, carbohydrate-based hybrid NCS offering high loading capacity, stability and sustained release of hydrophobic drugs can be excellent alternative to current AHT therapeutics.

Antihypertensive nano-ceuticales based on chitosan biopolymer: Physico-chemical evaluation and release kinetics.

Prime risk factor behind cardiovascular associated mortality and morbidity is hypertension. The main challenge with antihypertensive (AHT) drug therapy is their extreme hydrophobic nature and very low oral bio-availability; which result into higher dosage/frequency and associated side effects of drugs. The main objective of this study was to fabricate AHT nano-ceuticals in hydrophilic carriers of natural origin to improve drugs' solubility, protection and sustained release. AHT nano-carrier systems (NCS) encapsulating captopril, amlodipine and valsartan were fabricated using chitosan (CS) polymer by ionic gelation assisted ultra-sonication method. Drug encapsulation efficiencies of 92±1.6%, 91±0.9% and 87±0.5% were observed for captopril, valsartan and amlodipine respectively. Scanning electron microscopy (SEM) based analysis had revealed that captopril loaded polymeric NCS were regular, smooth and without any agglomeration. FTIR analyses of drug loaded and empty NCS demonstrated that drugs were molecularly dispersed inside the nanoparticles via week hydrogen bonding. Captopril and valsartan have demonstrated grafting reaction with N-H group of chitosan. Zeta sizer results had confirmed that average size of chitosan nanoparticles was below 100 nm. Encapsulation of captopril had reduced the surface charge value from +52.6±4.8 to +46.5±5.2 mV. Controlled release evaluation of highly encapsulated drug captopril had revealed a slow release in vitro from NCS in physiological buffer. Thus, here reported innovative AHT nano-ceuticals of polymeric origin can improve the oral administration of currently available hydrophobic drugs while providing the extended-release function.