Malnutrition caused by micronutrient deficiencies is not limited only to low-income countries but is also a problem in industrialised nations as well, affecting billions. To address this issue, countries have put in place several strategies. These include the fortification of staple and complementary foods and provision of supplements being some of them. Micronutrient deficiencies have been observed as being prevalent beyond just the disadvantaged segments of the population. Correcting micronutrient deficiencies can prevent up to four out of ten childhood deaths while lowering the maternal deaths by more than one third.
For several years, the bioavailability of ingested nutrients has been a challenge and therefore, a subject of focused research by academia and industry across the world. Since many orally ingested nutrients are not completely absorbed by the human body, scientists have been working on methods to improve their bioavailability. Nutrients ingested orally can be poorly permeable, soluble, or can get damaged by oxidation or peroxidation, thus reducing their availability at the target sites within the human body, eventually leading to low efficacy of the nutritional supplement itself.
In recent times though, advancements in biopharmaceutical nanotechnology have started changing the way nutrition is delivered. The potential of liposomal delivery systems in improving bioavailability is being recognised in the nutrition industry.
What are liposomal delivery systems?
Liposomes are nanoparticles or nanocarriers, usually 100-300 nm in diameter. They are formed spontaneously when certain phospholipids are hydrated with water. These spherical liposome vesicles can be used to microencapsulate and stabilise a variety of compounds in nutrition supplements and ensure their safe passage through the body till they reach the target site. They can be used as delivery vehicles for transporting substances into the body effectively by facilitating absorption directly in the mouth or by preventing a breakdown in the stomach. Their potential as drug delivery systems is promising because of their biocompatibility and ability to incorporate both hydrophilic and hydrophobic therapeutic agents.
The unique structure of liposomes makes them fit for use as robust encapsulation systems for the delivery of both lipophilic and hydrophilic functional compounds. Their spherical-shell structures comprising a phospholipid bilayer enclosing a liquid core helps to stabilise the encapsulated materials. The encapsulated functional compounds, like micronutrients, are protected against a range of environmental, enzymatic, and chemical stresses, including the presence of enzymes or reactive chemicals, and exposure to extreme pH, temperature, and ionic strength changes.
The pharmaceutical and food industry has been using a liposomal delivery system for their biocompatibility, improved bioavailability, biodegradability, absence of toxicity, nanosize, and ability to carry a wide variety of bioactive compounds. In the food industry, liposomes have recently been used to deliver different functional compounds in food systems.
Proving useful in nutrition supplements
Micronutrients like vitamins are important for human growth. However, most of them cannot be synthesised in the human body or are formed in insufficient amounts. Hence, it is important to provide vitamins in adequate quantities through a diet of fortified food or supplements. In their natural form, vitamins are easily degraded and possess poor bioavailability. Thus, it is essential to wrap these micronutrients in protective materials to prevent their deterioration during food processes and uptake in the body to enhance their solubility, stability, and targeting profile.
Vitamins can be encapsulated using delivery systems such as emulsion, solid–lipid nanoparticles, surfactant systems, and lipid encapsulation. Of these, liposome encapsulation technology appears promising due to its ability to prolong shelf life and improve the bioavailability of vitamins and a wide variety of hydrophilic and hydrophobic molecules such as peptides, proteins, Nucleic Acid Based Drugs (NABDs).
Studies have shown that liposome-based drug delivery systems are highly biocompatible and biodegradable due to their low intrinsic toxicity and immunogenicity and their capability to incorporate hydrophilic and hydrophobic compounds. They are being seen as ideal candidates to control/modulate the release of many kinds of active ingredients which play a role in nutrition supplements.
As per some studies, liposomal glutathione can restore immune system responses. Liposomal technology also applies well to water-soluble antioxidants like Vitamin C, increasing blood levels as compared to standard oral supplements. Liposome formulations are also useful in the case of lipid-soluble antioxidants like Coenzyme Q10 and offer better efficacy in the case of high-quality complex mixtures of pure compounds and botanicals.
Potential in tackling malnutrition
Given how useful liposomes can be in improving the bioavailability of micronutrients, one can surmise that this technology may be a useful asset in the arsenal of regimens used in the treatment of malnutrition.
Over the years studies have shown that dietary inadequacies in minute amounts of key vitamins and minerals are widespread in causing micronutrient malnutrition. Iron, Vitamin A and iodine deficiencies in microquantities are seriously impacting survival, intelligence, growth and development. Correcting micronutrient deficiencies can prevent up to four out of ten childhood deaths while lowering the maternal deaths by more than one third.
Micronutrient deficiencies have been observed as being prevalent beyond just the disadvantaged segments of the population. Estimates peg the population at risk of Vitamin A Deficiency (VAD), Iron Deficiency Anemia (IDA) and Iodine Deficiency Disorders (IDD), to be over three billion people .
To tackle micronutrient malnutrition, nutrients included in the fortification of foods must always prove their worth in safety, stability, bioavailability and performance. The stability of the nutrients and the product, and the bioavailability of the micronutrients (particularly iron and key vitamins like Vitamin A) is crucial .
Therapeutic foods and fortification with nutrient supplements can be used when appropriate stability of the active ingredient in the formulation is guaranteed. For this nano-formulations of active compounds using natural nanocarriers like liposomes can play a vital role in not only enhancing stability but also ensuring the controlled release of these nutrients.
Making the technology more accessible
It is important to note that while liposomal nanotechnology may seem very promising in helping address malnutrition, the cost-effectiveness of integrating this advanced technology into countrywide malnutrition programmes needs to be taken into consideration. This is where governments will have to step in to make the technology more accessible to the masses. Governments should look at introducing schemes and incentives for companies that manufacture lipid nanocarriers. This will encourage more companies to undertake research in the field of nano-formulations and more nutrition supplement manufacturers applying the technology to their formulations. State-funded research on the effectiveness of liposomal nano-formulations in treating malnutrition will open new opportunities for academia and industry alike. With proper support and awareness, there is no doubt that the nutritional industry's use of liposomes will grow rapidly in the next 5 to 10 years with the potential to favourably impact the world’s fight against malnutrition in the years to come.
Arun Kedia, Managing Director, VAV Life Sciences, Mumbai