Nanoencapsulation of Human Adipose Mesenchymal Stem Cells: Experimental Factors Role to Successfully Preserve Viability and Functionality of Cells

Cell nanoencapsulation is a novel delivery system based on a self-assembly technique mediated by electrostatic interactions called Layer-by-Layer (LbL) deposition, without an increase in volume implant because of the nanometric thickness of its layers. LbL coats the entire surface of individual cells, providing mechanical resistance to cells against manipulation and storage conditions prior to implantation in the patient. In this work, single-cell nanocapsule formation using human adipose-derived mesenchymal stem cells (ADSC) given their potentiality in regenerative medicine was assessed by fluorescence microscopy and Zeta potential assays. Both methodologies were conclusive in showing layer-by-layer nanocapsule formation of every single ADSC. Significant differences in terms of viability and cell functionality preservation were observed depending on the polycation used. Using a combination of fluorescence microscopy and fluorimetric assays, we found that cell survival after nanocapsulation was only efficient when chitosan was added to cells. These results were consistent with other cell types used in this study. Other polycations such as poly(allylamine hydrochloride) (PAH), poly(diallyldimethylammonium chloride) (PDADMAC) and poly-L-lysine (PLL) markedly decreased cell viability (22%, 11% and 15%, respectively). In addition, the use of potassium-enriched saline solutions, such as Hanks and Ringer’s solution, during the nanoencapsulation process on ADSCs was harmful on cell viability compared to standard media (36% vs 79%, respectively). The addition of a mixture of polyanions such as hyaluronic acid and chondroitin sulfate did not affect cell viability (79% and 81%). The combination of chitosan/hyaluronic acid and chondroitin sulfate was also effective in preserving the cell functionality of ADSCs, including the proliferation and differentiation of these cells as assessed by MTT assay and microscopy, respectively. Taken together, these results indicate that ADSCs can be successfully nanoencapsulated using a first layer of chitosan and a second layer of a combination of hyaluronic acid and chondroitin sulfate with a standard potassium concentration in the culture medium.

Nanoencapsulation of Antioxidant-Rich Fraction of Roasted <i>Moringa oleifera</i>L. Leaf Extract: Physico-Chemical Properties and <i>in Vitro</i>Release Mechanisms

Nanocapsules (NC) of antioxidant rich fraction of roasted Moringa leaves were prepared using emulsion coacervation technique with alginate (ALG) and/or chitosan (CTS) as biopolymers. NC were characterized based on particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE) and loading capacity (LC). Substituting CTS with ALG in NC caused a reduction in particle size and PDI, and enhanced EE. Mean particle size dropped from 1209 nm in 1:3 to 413 nm in 3:1 ALG/CTS-NC;PDI decreased from 0.9% to 0.2% and zeta potential from -5.4 to -28.1 mV. The highest EE (87.6%) and LC (13%) were obtained with ALG-CTS-NC (3:1). ALG-NC were spherical while both CTS and ALG-CTS-NC were ovoid. ALG and ALG-CTS-NC were oil/water emulsions while CTS-NC formed water/oil emulsions. 60% and 70% of bioactives in ALG-CTS-NC (3:1) were released in simulated gastric and intestinal fluids respectively after 400 min. Release of antioxidants from NC is concentration-dependent (First order model) and involves simultaneously diffusion (Higuchi model), swelling (korsmeyer-Peppas model) and erosion (Hixson-Crowell model) mechanisms.

Chlorogenic acid loaded chitosan nanoparticles with sustained release property,retained antioxidant activity and enhanced bioavailability

In this study,chlorogenic acid(CGA),a phenolic compound widely distributed in fruits and vegetables,was encapsulated into chitosan nanoparticles by ionic gelation method.The particles exhibited the size and zeta potential of 210 nm and 33 mV respectively.A regular,spherical shaped distribution of nanoparticles was observed through scanning electron microscopy(SEM)and the success of entrapment was confirmed by FTIR analysis.The encapsulation efficiency of CGA was at about 59%with the loading efficiency of 5.2%.In vitro ABTS assay indicated that the radical scavenging activity of CAG was retained in the nanostructure and further,the release kinetics study revealed the burst release of 69%CGA from nanoparticles at the end of 100th hours.Pharmacokinetic analysis in rats showed a lower level of Cmax,longer Tmax,longer MRT,larger AUC0et and AUC0e∞for the CGA nanoparticles compared to free CGA.Collectively,these results suggest that the synthesised nanoparticle with sustained release property can therefore ease the fortification of food-matrices targeted for health benefits through effective delivery of CGA in body.

Nanostructured food proteins as efficient systems for the encapsulation of bioactive compounds

Recently,nanoencapsulation was introduced as an efficient and promising approach for the protection,delivery,and site-specific liberation of the nutraceuticals and bioactive ingredients.Food proteins are attractive materials for developing nanocarriers to protect and deliver bioactives due to their unique functional and biological properties.Food proteins extracted from animals and plants have the ability to form different nanostructures including nanoparticles,hollow particles,nanogels,nanofibrillar aggregates,electrospun nanofibers,nanotubular structures,and nanocomplexes.These nanostructured food proteins have been widely used as nanocarriers for the biologically active compounds and drugs.The release of bioactive compounds from nanocarriers depends mainly on pH as well as swelling and the degradation behavior of nanostructure in the simulated physiological conditions.This review presents the applications of the nanostructured food proteins for the encapsulation of bioactive compounds.The major techniques for the fabrication of nanocarriers are described.The encapsulation,protection,and release of bioactive compounds in different nanostructured food proteins were also discussed.

Fabrication, characterization, in vitro drug release and glucose uptake activity of 14-deoxy,11, 12-didehydroandrographolide loaded polycaprolactone nanoparticles

Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly water soluble compound) loaded polycaprolactone(nanoDDA) was synthesized using the solvent evaporation technique. Nano-DDA was characterized by scanning electron microscopy(SEM) and dynamic light scattering(DLS) studies. Fourier Transform InfraRed Spectroscopy(FTIR) was used to investigate the structural interaction between the drug and the polymer. Functional characterization of the formulation was determined using drug content, cellular uptake and in vitro drug release. 2-deoxy-D-[1-~3H] glucose uptake assay was carried out to assess the antidiabetic potential of nano-DDA in L6 myotubes.The nano-DDA displayed spherical shape with a smooth surface(252.898 nm diameter), zeta potential, encapsulation and loading efficiencies of -38.9 mV, 91.98 ± 0.13% and 15.09 ± 0.18% respectively. No structural alteration between the drug and the polymer was evidenced(FTIR analysis). Confocal microscopy studies with rhodamine 123 loaded polycaprolactone nanoparticles(Rh123-PCL NPs) revealed the internalization of Rh123-PCL NPs in a time dependent manner in L6 myoblasts. A dose dependent increase in glucose uptake was observed for nano-DDA with a maximal uptake of 108.54 ± 1.42% at 100 nM on L6 myotubes, thereby proving its anti-diabetic efficacy. A biphasic pattern of in vitro drug release demonstrated an initial burst release at 24 h followed by a sustained release for up to 11 days. To conclude,our results revealed that nano-DDA formulation can be a potent candidate for antidiabetic drug delivery.

Physicochemical Properties and Control Release of Aloe Vera (Aloe barbadensis Miller) Bioactive Loaded Poly (Lactic Co-Glycolide Acid) Synthesized Nanoparticles

Nano-encapsulation is a platform which offers a promising application for control release and the delivery of drugs in pharmaceuticals and antioxidant/ antimicrobial in food systems. Poly (lactic-co-glycolide acid) (PLGA) is a biodegradable and biocompatible co-polymer of lactic acid and glycolic acid which is used for synthesizing food based polymeric nanoparticles (NP). The aim of this study was to evaluate the morphological and physicochemical properties and the controlled release of bioactive components derived from Aloe vera gel loaded PLGA NP. The results shows the mean hydrodynamic diameter of the unloaded NP is 103 nm which is significantly (p < 0.01) smaller than the loaded freeze dried powered gel (FDG) (147 nm) and liquid gel (LG) (221 nm) and the particle size distribution given by the Poly-dispersity Index were 0.2, 0.2 and 0.3, respectively. The zeta potential for unloaded, FDG and LG NP were ±60, ±28 and ±22 mV, respectively, hence were electrokinetically stable NP. No significant (p > 0.05) inhibition of the antioxidant potential was observed with loaded NP. The entrapment efficiency for the FDG synthesized was 87%, and the burst effect was observed after 4 h as a result of the encapsulation effect. The release kinetics of bioactive is govern by the combination of mass diffusion and capillary action.

Nano-Microencapsulation and Controlled Release of Linoleic Acid in Biopolymer Matrices: Effects of the Physical State, Water Activity, and Quercetin on Oxidative Stability

In this study, linoleic acid (LA) was encapsulated in the presence or absence of quercetin into a dual polymer system of whey protein and kappa-carrageenan using power ultrasound. Atomic Force Microscopy (AFM) and FlowCam imaging technology were used for imaging and size determination of nano-and micro-capsules. Differential scanning calorimeter (DSC) was used to determine the glass transition temperature (Tg) of the freeze-dried nanocapsules. In order to examine the effect of water activity (aw) on the release profile of the encapsulated LA, the nanocapsules were equilibrated over saturated salt solution conditions corresponding to the range of aw between 0.333 and 0.769 in evacuated desiccators at room temperature. Gravimetric measurements of the steady state linoleic acid (LA) contents were conducted. The anti-oxidant activity of quercetin and the stability of encapsulated LA toward long term and thermally induced rancidity was investigated. The capsules were in the nanosize regime and 83% of the LA was effectively encapsulated. Furthermore, at aw of 0.764, the highest percentage of LA (74%) was released from the expelling nanocapsules. Quercetin was found to exhibit protective antioxidant effect against time-dependent oxidation and thermally induced rancidity of LA. Water activity values of 0.662 and 0.764 provided ideal humidity and pressure conditions for sustained release of nanoencapsulated LA at room temperature.

Advances in the research and application of neurokinin-1 receptor antagonists

Recently,the substance P(SP)/neurokinin-1 receptor(NK-1R)system has been found to be involved in various human pathophysiological disorders including the symptoms of coronavirus disease 2019(COVID-19).Besides,studies in the oncological field have demonstrated an intricate correlation between the upregulation of NK-1R and the activation of SP/NK-1R system with the progression of multiple carcinoma types and poor clinical prognosis.These findings indicate that the modulation of SP/NK-1R system with NK-1R antagonists can be a potential broad-spectrum antitumor strategy.This review updates the latest potential and applications of NK-1R antagonists in the treatment of human diseases and cancers,as well as the underlying mechanisms.Furthermore,the strategies to improve the bioavailability and efficacy of NK-1R antagonist drugs are summarized,such as solid dispersion systems,nanonization,and nanoencapsulation.As a radiopharmaceutical therapeutic,the NK-1R antagonist aprepitant was originally developed as radioligand receptor to target NK-1R-overexpressing tumors.However,combining NK-1R antagonists with other drugs can produce a synergistic effect,thereby enhancing the therapeutic effect,alleviating the symptoms,and improving patients’quality of life in several diseases and cancers.

Drug-nanoencapsulated PLGA microspheres prepared by emulsion electrospray with controlled release behavior

The development of modern therapeutics has raised the requirement for controlled drug delivery system which is able to efficiently encapsulate bioactive agents and achieve their release at a desired rate satisfying the need of the practical system.In this study,two kind of aqueous model drugs with different molecule weight,Congo red and albumin from bovine serum(BSA)were nanoencapsulated in poly(DL-lactic-co-glycolic acid)(PLGA)microspheres by emulsion electrospray.In the preparation process,the aqueous phase of drugs was added into the PLGA chloroform solution to form the emulsion solution.The emulsion was then electrosprayed to fabricate drugnanoencapsulated PLGA microspheres.The morphology of the PLGA microspheres was affected by the volume ratio of aqueous drug phase and organic PLGA phase(V_(w)/V_(o))and the molecule weight of model drugs.Confocal laser scanning microcopy showed the nanodroplets of drug phase were scattered in the PLGA microspheres homogenously with different distribution patterns related to V_(w)/V_(o).With the increase of the volume ratio of aqueous drug phase,the number of nanodroplets increased forming continuous phase gradually that could accelerate drug release rate.Moreover,BSA showed a slower release rate from PLGA microspheres comparing to Congo red,which indicated the drug release rate could be affected by not only V_(w)/V_(o)but also the molecule weight of model drug.In brief,the PLGA microspheres prepared using emulsion electrospray provided an efficient and simple systemto achieve controlled drug release at a desired rate satisfying the need of the practices.

Fast-dissolving antioxidant nanofibers based on Spirulina protein concentrate and gelatin developed using needleless electrospinning

Spirulina is a microalga that is well-known for its high protein content and biological activities directly related to its antioxidant capacity.The objective of this study was to produce fast-dissolving antioxidant nanofibers based on Spirulina protein concentrate (SPC) and gelatin using needleless electrospinning technique.The effect of mixing ratios of SPC (10% w/w) and gelatin (20% w/w) on the viscosity,electrical conductivity and surface tension of electrospinning solutions as well as diameter and morphology of resulting nanofibers was investigated.Increasing the SPC level in the solution blends resulted in a decrease in apparent viscosity and electrical conductivity and an almost stable trend in surface tension (29.25–32.19 mN/m) that led to diminish of diameter of the nanofibers.Scanning electron microscopy images showed that SPC/gelatin ratio of 40:60 led to the production of uniform and bead-free nanofibers with a relatively smaller average diameter (208.7 ± 46.5 nm).Atomic force microscopy images indicated mesh-like,fibrillary,and bead-free structures.Fourier transform infrared spectroscopy verified the formation of composite nanofibers and intermolecular interactions between both proteins.X-ray diffraction and thermal analysis showed higher amorphous structure and stability of produced SPC/gelatin nanofibers in comparison to pure materials which was favorable for formation of stable fast-dissolving fibers.Results of DPPH and ABTS radical scavenging activities showed that the antioxidant activity of composite nanofibers significantly improved with increasing SPC mixing ratio (p < 0.05).The dissolution test demonstrated that SPC/gelatin nanofibers can be rapidly dissolved in aqueous medium within 2 s.Finally,the results indicated that the electrospun SPC/gelatin nanofibers could be potentially used for nutraceutical delivery in food and packaging applications under high humidity.