Biomedical potential of clay nanotube formulations and their toxicity assessment

ABSTRACT

Introduction: Halloysite clay nanotubes (HNTs) are a naturally abundant and biocompatible aluminosilicate material with a structure able to encapsulate 10–20% of drugs. These features are attractive toward the clinical application in controlled drug delivery, tissue engineering and regenerative medicine.

Areas covered: We describe the application of HNTs as a viable method for clinical purposes, particularly developing formulations for prophylaxis, diagnosis and therapeutics, having a special attention to these nanotubes bio-safety. HNTs may be used for pharmaceuticals, biopharmaceuticals, wound healing, bone regeneration, dental repair, hair surface engineering and biomimetic applications.

Expert opinion: HNTs are a versatile, safe and biocompatible nanomaterial used for drug encapsulation for numerous clinical applications. The studies here reviewed confirm the HNTs biocompatibility, describing their low toxicity. Further developments will be made regarding the long-term efficacy of halloysite-based treatments in humans, concentrating mostly on topical applications.

KEYWORDS:

• Halloysite clay nanotubes
• drug therapy
• biosensor
• bioimaging
• tissue engineering
• regenerative medicine
• toxicity

Article highlights

• Drug loading in halloysite clay nanotubes (HNTs) for distinct medical therapies.

• Enzyme and DNA immobilization in HNTs for diagnosis and therapy.

• Composites of HNTs as potential theranostic agents.

• Drug loading in HNTs for wound-healing and bone/dental repair.

• HNTs for hair coating with targeted drug delivery towards parasitic infection treatment.

• HNTs are a safe, biocompatible and abundantly available nanomaterial.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

Y Lvov was supported by the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST «MISiS» (К3-2018-031) by a state decree of March 2013, #211. I Pereira was supported by the PhD research grant SFRH/BD/136892/2018 funded by Fundação para a Ciência e a Tecnologia (FCT) and Programa Operacional Capital Humano (POCH).