Nanogels: the future of smart drug delivery

Nanomedicine is a rapidly advancing field, with nanogels emerging as promising innovations for drug delivery applications. Nanogels are soft nanoscale hydrogels that are transforming how we deliver drugs and treat diseases. Whilst hydrogels themselves have long been used in biomedical applications such as tissue engineering and wound healing, their relatively larger sizes (above 100 micrometres) limits their ability to interact with cells and cross biological barriers. Nanogels, however, are thousands of times smaller, and offer unique advantages as a result.

What are nanogels?

Nanogels are tiny, water swollen polymer networks and are made up of crosslinked polymer chains to form a 3D matrix. Nanogels can encapsulate therapeutic agents inside their porous core shell structure. This swelling allowing nanogels to carry payloads, such as drugs, proteins, nucleic acids and these cargo materials are protected from degradation in the body whilst enabling controlled and targeted delivery. Due to their small sizes, nanogels can penetrate tissues and even enter cells, which overcomes the limitations faced with hydrogels. The surface of nanogels can also be engineered for specificity, to allow for precise targeting of drugs to receptors on diseased cells or inflamed tissues.

Advantages over other nanocarriers

Compared to liposomes and polymeric micelles, nanogels have a larger inner surface, which means they can carry more payload. The higher loading capacity improves the therapeutic efficiency whilst reducing the risks of side effects cause by off-target drug release. Nanogels also undergo the enhanced permeability and retention (EPR) effect - a phenomenon where the nanoparticles naturally accumulate in tumour or inflamed tissues due to leaky blood vessel, and as a result this improves drug delivery to targeted disease sites.

Stimuli responsive ‘smart’ nanogels

A key feature of nanogels is their stimuli responsiveness, or ability to act as ‘smart’ materials. The nanogels can be designed to respond to environmental triggers such as changes in pH, temperature, light, redox conditions, pressure and more. This responsiveness enables controlled release of drugs exactly when and where they are needed12. For example, thermoresponsive nanogels can change their structure at body temperature or when exposed to localised heating, making them ideal for applications like wound healing and cancer therapy. This controlled release prevents premature drug leakage, reduces systemic toxicity and overall improves the precision of the treatment.

The future of nanogels in medicine

Nanogels have huge potential as customisable drug delivery systems to target specific disease systems. They are biocompatible, stable, and have high drug loading capacities and are stimuli responsive; these properties combined make them a powerful tool in applications such as targeted drug delivery and gene therapy.

As nanomedicine research progresses, nanogels are set to revolutionise healthcare with smarter, safer and more targeted therapies. 

Written by Saanchi Agarwal

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