Gastrointestinal Mucosa: The Target Site of Mucoadhesive Microspheres, A Review

Pectin Microspheres: Synthesis Methods, Properties, and Their Multidisciplinary Applications

There is great contemporary interest in using cleaner technologies through green chemistry and utilizing biopolymers as raw material. Pectin is found on plant cell walls, and it is commonly extracted from fruit shells, mostly apples or citrus fruits. Pectin has applications in many areas of commercial relevance; for this reason, it is possible to find available information about novel methods to transform pectin and pursuing enhanced features, with the structuring of biopolymer microspheres being highly cited to enhance its activity. The structuring of polymers is a technique that has been growing in recent decades, due to its potential for diverse applications in various fields of science and technology. Several techniques are used for the synthesis of microspheres, such as ionotropic gelation, extrusion, aerosol drying, or emulsions, with the latter being the most commonly used method based on its reproducibility and simplicity. The most cited applications are in drug delivery, especially for the treatment of colon diseases and digestive-tract-related issues. In the industrial field, it is used for protecting encapsulated compounds; moreover, the environmental applications mainly include the bioremediation of toxic substances. However, there are still many possibilities for expanding the use of this biopolymer in the environmental field.

ι-Carrageenan nanocomposites for enhanced stability and oral bioavailability of curcumin

Background

Carrageenan (CRN), a polygalactan consisting of 15 to 40% ester sulfate, is used in oral controlled-release technology due to its viscosity and large molecular weight. Curcumin (Cur) is a highly potent antioxidant and anti-inflammatory agent against various diseases, such as tumors, liver disease, rheumatism, and Alzheimer’s disease. Although Cur shows excellent effects in the body, it has major problems, such as poor solubility and low bioavailability in water.

Method

Nanocomposites containing Cur were developed by emulsion technique. Cur@CRN was characterized through the viscosity measurement, size analysis, stability test, and loading efficiency. Antioxidant effects was analyzed with DPPH reagent, and anti-inflammatory effects was analyzed by NFkB/IkBr signaling pathway with wester blot. Cellular interaction was confirmed by flow cytometry and confocal images. Especially, permeability test was demonstrated in MDCK and Caco-2 monolayer cells.

Results

Cur@CRN enhanced stability, antioxidant, and anti-inflammatory effects in vitro, compared with other polymer nanocomposites. Sulfate groups (SO₄²⁻) in CRN are transported across cell membranes by anion exchangers of the SLC26 gene families. We confirmed Caco-2 cells expressed SLC26A2 receptors interacted with CRN, expect for Tween 80 and hydroxypropyl cellulose. In contrary, other cells did not interact with CRN due to non-expression of SLC26A2 receptors. Based on this, Cur@CRN showed 44-fold better permeability than free Cur in MDCK cell assay.

Conclusion

Enhanced intestinal permeability of Cur can be applied in various health care facilities with significant antioxidant and anti-inflammatory effects compared with nonformulated Cur. Since the CRN composed of nanocomposites has a high molecular weight, high viscosity, and sulfate groups, it will be a platform that can increase the bioavailability of various insoluble drugs as well as Cur.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40824-021-00236-4.

Preparation of Alginate-Based Biomaterials and Their Applications in Biomedicine

Alginates are naturally occurring polysaccharides extracted from brown marine algae and bacteria. Being biocompatible, biodegradable, non-toxic and easy to gel, alginates can be processed into various forms, such as hydrogels, microspheres, fibers and sponges, and have been widely applied in biomedical field. The present review provides an overview of the properties and processing methods of alginates, as well as their applications in wound healing, tissue repair and drug delivery in recent years.

Mucoadhesive gastroretentive microparticulate system for programmed delivery of famotidine and clarithromycin

AIM

The present research was aimed to develop thiolated polyacrylic acid (TPA) based microspheres (MSPs) containing famotidine (FX) and clarithromycin (CLX).

METHODS

TPA was synthesised from polyacrylic acid and l-cysteine in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC). The prepared TPA was characterised using FT-IR (Fourier transform-infra red), ¹H-NMR (proton nuclear magnetic resonance) spectroscopy, P-XRD (powder X ray diffraction) method, and zeta potential. The analytical tools have supported the formation of TPA. The thiolated microspheres were prepared by emulsion solvent evaporation method using 0.75% w/v polymer concentration and stirring at 400 rpm for 8 hr.

RESULTS

The average particle size and zeta potential of optimised formulation was found to be 25.2 ± 1.87 μm and -26.68 mV, respectively. The entrapment efficiency of the optimised formulation was obtained 67.20% for FX and 70.20% for CLX. The developed microspheres were swelled only in 4 h from 0.5 to 0.9. The in vitro mucoadhesive study and in vitro drug release studies demonstrated that microspheres showed mucoadhesive property. In in vitro drug release studies, the release of FX and CLX were observed to be 58.68% and 60.48%, respectively from microspheres in 8 h. The thiolated microspheres showed higher adhesion time (7.0 ± 0.8 h) in comparison to the plain microspheres (2.6 ± 0.4 h).

CONCLUSION

The prepared TPA based mucoadhesive microspheres can be utilised as carriers for the treatment of peptic ulcer caused by Helicobacter pylori which will offer enhanced residence time for the rational drug combination in the gastric region.

Overcoming T. gondii infection and intracellular protein nanocapsules as biomaterials for ultrasonically controlled drug release

One of the pivotal matters of concern in intracellular drug delivery is the preparation of biomaterials containing drugs that are compatible with the host target.