Folate-Modified Chitosan 5-Flourouraci Nanoparticles-Embedded Calcium Alginate Beads for Colon Targeted Delivery

An oral delivery approach for riboflavin-targeted platinum(II)-loaded lipid nanoparticles into alginate-gelatin matrices against 2D and 3D colorectal carcinoma models

This study investigated the use of riboflavin-targeted Nanostructured Lipid Carriers (R-NLCs) to deliver a platinum-based anticancer drug [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) to colorectal cancer cells. Three different R-8-QO-Pt-NLC formulations were prepared via hot-homogenization by ultrasonication method. The physicochemical characterizations of NLCs were analyzed by small- and wide-angle X-ray scattering (SAXS/WAXS) and fourier transformed infrared spectroscopy (FTIR). The cytotoxic effects and IC50 values of R-8-QO-Pt-NLC formulations were compared with those of the free 8-QO-Pt. Cellular uptake and apoptosis were evaluated towards HCT 116 cells in monolayer (2D). The liquid overlay technique was used to generate 3D multicellular tumor spheroids, MCTS. The anticancer and antimetastatic activities of the free 8-QO-Pt and R-8-QO-Pt-NLCs were determined in MCTS. The results revealed that R-8-QO-Pt-NLC exhibited greater cytotoxicity and lower IC50 values than free 8-QO-Pt in both 2D and 3D cell cultures. Furthermore, results showed that the volumes of the spheroids were reduced in response to increasing concentrations of R-8-QO-Pt-NLC, showing higher inhibition of cell migration in colorectal cancer spheroids at concentrations of 10.0, 15.0, and 25.0 μM than free 8-QO-Pt. To provide protection against gastric acid conditions, an additional drug delivery system based on alginate (Alg) and gelatin (Gel) beads for R-8-QO-Pt-NLC oral administration was developed. While free and R-NLC encapsulated 8-QO-Pt were practically inactivated at pH 1.2 and 37 °C, it was revealed that the Alg-Gel beads retain 5.7 times the initial activity of the R-8-QO-Pt-NLC. The findings of this research indicate that R-8-QO-Pt-NLC embedded in Alg-Gel beads are promising hydrogels for targeted colorectal delivery systems.

Construction of biopolymer-based hydrogel beads for encapsulation, retention, and colonic delivery of tributyrin: Development of functional beverages (fortified bubble tea)

Tributyrin (TB) can be hydrolyzed into short chain fatty acids (butyric acid) in the gastrointestinal tract, which are claimed to exhibit beneficial health effects in the colon. However, digestion of tributyrin in the stomach and small intestine may promote its absorption in the upper gastrointestinal tract, thereby reducing its potential colonic health benefits. In this study, we therefore developed a novel method of encapsulating emulsified tributyrin within biopolymer-based hydrogel beads (≈ 800 μm) that were then encapsulated inside the boba beads (≈ 8-10 mm) found in bubble tea. The hydrogel beads were designed to retain and protect the tributyrin under upper gastrointestinal tract (GIT) conditions, but then release it within the colon. The concentration of tributyrin within the boba beads was 33.3 mg/g, which is above the value reported to exhibit health benefits. The morphology, encapsulation properties, water holding capacity, stability, and swelling properties of the tributyrin-loaded boba beads were characterized. Tapioca-based beads exhibited a larger degree of swelling when incubated in water for 12h (>95 %), whereas agar-based beads did not (< 20 %). In addition, the potential gastrointestinal fate of both free and encapsulated tributyrin oil droplets was assessed using an in vitro digestion model. The free tributyrin oil droplets were almost completely hydrolyzed (103.2 %) by the end of the small intestine phase, whereas the tributyrin oil droplets encapsulated within the agar-based (29.4 %) or tapioca-based (40.3 %) boba beads were much more resistant to digestion. The tapioca-based beads were partially broken down as they passed through the simulated GIT, while the agar-based beads maintained their structural integrity. The tapioca-based beads were gradually broken down as they passed through the simulated GIT, while the agar-based ones maintained their structural integrity. Agar beads were also harder, more resilient, and chewier than the tapioca ones. Both types of boba beads tended to swell and disintegrate when heated to high temperatures (90 °C), with the effect being more pronounced for the agar beads. Overall, our results suggest that the agar-based boba beads had greater potential for the delivery of tributyrin to the colon than the tapioca-based ones. The recent popularity of bubble tea means that it may be a suitable vehicle for delivering bioactive food components, like functional lipids, vitamins, nutraceuticals, or probiotics.

Preparation and In Vitro Characterization of Lactococcus lactis-Loaded Alginate Particles as a Promising Delivery Tool for Periodontal Probiotic Therapy

Probiotic microorganisms are used in a variety of food supplements and medical formulations to promote human health. In periodontal therapy, probiotics are mainly used in the form of gels, tablets or rinses that often tend to leak from the periodontal pocket, resulting in a strongly reduced therapeutic effect. In this pilot in vitro study, we present biodegradable alginate-based particles as an alternative, highly efficient system for a periodontal delivery of probiotic bacteria to the inflammation site. For this purpose, Lactococcus (L.) lactis was encapsulated using a standardized pump-controlled extrusion-dripping method. Time-dependent bacterial release in artificial saliva was investigated over 9 days. The effect of freeze drying was explored to ensure long-term storage of L. lactis-loaded particles. Additionally, the particles were bound to dentin surface using approved bioadhesives and subjected to shear stress in a hydrodynamic flow chamber that mimics the oral cavity in vitro. Thus, round particles within the range of 0.80-1.75 mm in radius could be produced, whereby the diameter of the dripping tip had the most significant impact on the size. Although both small and large particles demonstrated a similar release trend of L. lactis, the release rate was significantly higher in the former. Following lyophilization, particles could restore their original shape within 4 h in artificial saliva; thereby, the bacterial viability was not affected. The attachment strength to dentin intensified by an adhesive could resist forces between 10 and 25 N/m2. Full degradation of the particles was observed after 20 days in artificial saliva. Therefore, alginate particles display a valuable probiotic carrier for periodontal applications that have several crucial advantages over existing preparations: a highly stable form, prolonged continuous release of therapeutic bacteria, precise manufacturing according to required dimensions at the application site, strong attachment to the tooth with low risk of dislocation, high biocompatibility and biodegradability.

Targeting the Gut: A Systematic Review of Specific Drug Nanocarriers

The intestine is essential for the modulation of nutrient absorption and the removal of waste. Gut pathologies, such as cancer, inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS), and celiac disease, which extensively impact gut functions, are thus critical for human health. Targeted drug delivery is essential to tackle these diseases, improve therapy efficacy, and minimize side effects. Recent strategies have taken advantage of both active and passive nanocarriers, which are designed to protect the drug until it reaches the correct delivery site and to modulate drug release via the use of different physical-chemical strategies. In this systematic review, we present a literature overview of the different nanocarriers used for drug delivery in a set of chronic intestinal pathologies, highlighting the rationale behind the controlled release of intestinal therapies. The overall aim is to provide the reader with useful information on the current approaches for gut targeting in novel therapeutic strategies.

Microbiota-sensitive drug delivery systems based on natural polysaccharides for colon targeting

Colon targeting is an ongoing challenge, particularly for the oral administration of biological drugs or local treatment of inflammatory bowel disease (IBD). In both cases, drugs are known to be sensitive to the harsh conditions of the upper gastrointestinal tract (GIT) and, thus, must be protected. Here, we provide an overview of recently developed colonic site-specific drug delivery systems based on microbiota sensitivity of natural polysaccharides. Polysaccharides act as a substrate for enzymes secreted by the microbiota located in the distal part of GIT. The dosage form is adapted to the pathophysiology of the patient and, thus, a combination of bacteria-sensitive and time-controlled release or pH-dependent systems can be used for delivery.

Chitosan-Based Nanoparticles with Optimized Parameters for Targeted Delivery of a Specific Anticancer Drug-A Comprehensive Review

Chitosan is a positively charged polysaccharide obtained through chitin deacetylation. It belongs to a group of biodegradable, bioavailable, and non-toxic materials of natural origin; thus, it is a promising matrix for creating delivery systems of different active agents. Recently, much attention has been paid to nanodelivery systems as carriers to enable better bioavailability, and thus higher efficiency of the loaded drug. The present review is focused on the progress in chitosan-based nanoparticles for the targeted delivery of antitumor drugs. The paper discusses literature reports from the last three years in which chitosan nanoparticles were applied as carriers for active substances used in antitumor therapy and potential new drugs with anticancer properties. Special attention was paid to the different treatments applied to increase the therapeutic effectiveness and minimize the side effects of a specific active substance.

Formulation and Evaluation of Chitosan-Gelatin Thermosensitive Hydrogels Containing 5FU-Alginate Nanoparticles for Skin Delivery

(1) Background: Chitosan-gelatin-based thermosensitive hydrogel containing 5FU-alginate nanoparticles was formulated for the effective and sustained delivery of 5FU to the skin. (2) Methods: Alginate, a polysaccharide was used for the formulation of nanoparticles using a spray drying technique. Size, zeta potential, and surface morphology were investigated using a zetasizer and scanning electron microscope. The hydrogel was fabricated using chitosan and gelatin. Several important analyses were used to characterize these prepared topical hydrogels. The pH, visual transparency, rheological behavior, and swelling index of the prepared hydrogels were evaluated. The in vitro release studies were performed at different pH (5.5 and 7.4) and temperature (32 and 37 °C) conditions using a Franz diffusion cell. Ex vivo permeation and in vivo studies were performed using Sprague Dawley rats. (3) Results: Results show that spherical nanoparticles were produced at sizes of 202−254 nm and with zeta potentials of −43 to −38 mV. The prepared nanoparticles were successfully incorporated into chitosan-gelatin-based hydrogels using a glycerol 2-phosphate disodium salt hydrates crosslinker. Drug polymers and excipients compatibility and formulation of hydrogels was confirmed by ATR-FTIR results. The pH of the prepared hydrogels was in accordance with the skin pH. The viscosity of prepared hydrogel increased with temperature increase and phase transition (sol-gel transition) occurred at 34 °C. The release of drug was sustained in case of nanoparticles incorporated hydrogels (5FU-Alg-Np-HG) as compared to nanoparticles (5FU-Alg-Np) and simple hydrogels (5FU-HG) (ANOVA; p < 0.05). The premature and initial burst release of 5FU was prevented using 5FU-Alg-Np-HG. The release mechanism of 5FU from the 5FU-Alg-Np-HG diffusion was followed by swelling and erosion, as suggested by Korsmeyer-Peppas model. The prepared hydrogel proved to be non-irritant. Ex vivo permeation study across rat’s skin suggests that permeability of nanoparticles (5FU-Alg-Np) was higher than the 5FU-Alg-Np-HG (ANOVA; p < 0.05). However, skin-related drug retention of 5FU-Alg-Np-HG was significantly higher than the 5FU solution, 5FU-Alg-Np, and 5FU-HG (ANOVA; p < 0.05). This was due to swelling of hydrogels in the lower layers of skin where the temperature is 37 °C. The higher concentration of 5FU in the skin is helpful for treatment of local skin cancer, such as melanoma, and actinic keratosis. In vivo results also confirmed maximum AUC, t1/2, and skin-related drug retention of 5FU-Alg-Np-HG. (4) Conclusions: Chitosan-gelatin-based hydrogels containing 5FU-Alg-Np possess exceptional properties, and can be used for the sustained delivery of 5FU for the treatment of local skin cancers.