Bentonite Clays for Therapeutic Purposes and Biomaterial Design

Abstract

Background: Bentonite is a natural clay composed mainly of montmorillonite with other associated minerals such as feldspar, calcite and quartz. Owing to its high cation exchange, large surface area and ability to form thixotropic gels with water and to absorb large quantities of gas, it presents a large medicinal application. Objective: This review focuses on the promising potential of bentonite clays for biomaterial design and for therapeutic purposes. Methods: PubMed, ACS publications and Elsevier were searched for relevant papers. We have also evaluated the references of some pertinent articles. Results: Healing properties of bentonite are derived from the crystalline structure of the smectite group, which is composed of two octahedral alumina sheets localized between two tetrahedral silica sheets. This structure is behind the ability to intercalate cationic bioactive agents and undergoes interaction with various toxic species and exchanging in return species such as Fe3+, Cu2+, Al3+ Ca2+ or Na+, presenting antibacterial activity and providing essential minerals to the body. Furthermore, due to to its layered structure, bentonite has wide application for the design of biomaterials providing, thus, the stability of bioactive agents and preventing them from aggregation. Conclusion: Numerous publications have cited bentonite extensive applications as an alternative and complementary treatment for numerous health conditions as a detoxifying agent and for the preparation of several bionanocomposites.

Co-exchanged montmorillonite: a potential antibacterial agent with good antibacterial activity and cytocompatibility

“…Since the binding between exchangeable cations and MMT was unstable, these cations will be released into the medium continuously, which gives MMT good drug loading and sustained release ability. 14 Moreover, MMT also has the ability to adsorb bacteria and toxins due to its charge characteristics and high specific surface area. 16,17 Therefore, MMT has been widely used as a drug carrier or toxin adsorbent in the antibacterial field.…”

“…[10][11][12] Due to its intercalation/ exchange capacities and high specific surface area, MMT has been used as a carrier for metal ions or drugs. 13,14 Moreover, studies have shown that MMT has various therapeutic applications such as wound healing, adsorption of bacterial strains, and haemorrhage control in trauma patients. [15][16][17] It has been reported that ion-exchanging MMT, such as AgMMT, has good antibacterial and anti-biofilm activities.…”

Streptomyces Isolates from the Soil of an Ancient Irish Cure Site, Capable of Inhibiting Multi-Resistant Bacteria and Yeasts

“…There is also the possibility that other types of bacteria could also be associated with the reputed antimicrobial activity of this soil; however, in this study we concentrated solely on Streptomyces. Additionally, the activity of the Blessed clay could equally be based on some type of clay mineral, such as Montmorillonite [40,41] or sulfurand iron-reducing bacteria [42]. However, the Blessed clay in this study has a silty-loam consistency rather than clay-like, similar to the rest of the soil found in this area.…”

Regenerative and anti‐inflammatory effect of a novel bentonite complex on burn wounds

“…Bentonites, which originate from altered volcanic ash, have been used as major components in cosmetic and medical products [10][11][12][13]. Formerly, bentonite has been considered a therapeutic material and even applied to wounds in cases of emergencies [14].…”