What is a liposome? Man-made phospholipid bilayer spheres
In Greek, the word ‘Lipos’ means fat and ‘soma’ means body. Therefore ‘liposome’ literally means a body of fat.
Phospholipids in liposomes
Phospholipids make up the liposomes within our supplements. Fatty acid chains attached to a glycerol backbone in turn make up phospholipids. However, the glycerol backbone in phospholipids have only two connecting fatty acids (diacylglycerol). A modified phosphate group occupies the third carbon of the backbone in phospholipids. A phospholipid thus has a phosphoglycerol group that comprises the ‘head’.
Two fatty acid side chains comprise the ‘tail’ of a phospholipid (1). They can either be saturated or unsaturated fatty acids.
Liposomes versus micelles
The composition of phospholipids is integral to their behavior in water. This is crucial to their role in liposomal supplements. Having a negative charge, the phosphate group makes the head hydrophilic (water-loving). The tails on the other hand, have no charge on them and are thus hydrophobic (water-repelling). Thus, when added to water, phospholipids will spontaneously rearrange. Their rearrangement into a single layer sphere is called a micelle. In a micelle, only the hydrophilic phosphate heads are in contact with water.
How liposomes are different from micelles
A liposome, while resembling a micelle, is very different. The difference is in that it is a sphere composed of one or more phospholipid bilayers. In order to arrange into a bilayer, we need energy in the form of heat, homogenization or ultrasonic waves.
“Liposomes are a bubble-like structure composed of molecules called phospholipids. In the outer shell, the phospholipids’ water-loving heads face outside. In the inner shell, the heads face an aqueous core. The phospholipid tails are between these two layers. “
Our liposome manufacturing process for the production of food supplements
As afore mentioned, a liposome is artificially created. The first step in the process is to combine a plant-based lecithin or chemically synthesized phospholipid with water. This is then combined with the active ingredient (vitamin, mineral or phytoextract) in precise ratios. The mixture is then treated with an external form of energy, resulting in the encapsulation of the active ingredient within liposomes. This is the principle behind our liposomal supplements. We encapsulate hydrophilic (water-loving and fat-repelling) ingredients in the aqueous core. Lipophilic (fat-loving and water-repelling) ingredients are, on the other hand, encapsulated within the lipid bilayer of the liposome. The liposome and its encapsulated ingredients are themselves, fully water-soluble at this point (2,3).
The absorption of liposomal supplements by the human body
The absorption of lipids and phospholipids by the small intestine is a well-known process. Recent studies have shown that liposomes and the ingredients that they encapsulate, are similarly digested and absorbed (4,5). The small intestine typically digests the phospholipids and not the stomach. Hence, liposomes protect the encapsulated ingredients from gastric digestion. This results in their protection from a potential loss of activity. The gastric tract is also protected from the potential inflammatory effects of the encapsulated ingredient.
Absorption of liposomes
The gastric stability and intestinal absorption of liposomes are highest at the nanoscopic level (<150nm). This is because the small size increases the retention time in the first part of the small intestine. This, in turn, allows for increased absorption and decreased excretion of the active ingredient.
Might be of interest – PlantaCorp’s Liposome Product Process
How liposomal supplements reach the bloodstream
Active ingredients that pass through the liver are metabolized, leading to a potential loss of ingredients. Diverting the ingredients towards the intestinal lymphatic system, avoids the portal vein. This means that rather than passing through the liver, the ingredient directly reaches the bloodstream. This diversion is possible when the ingredients are accompanied by lipid molecules. Reaching the bloodstream without passing the liver, increases their bioavailability . This is a reason why liposomal supplements are more bioavailable than conventional supplements.
Liposomes: Increasing the bioavailability of encapsulated ingredients
Bioavailability refers to the amount of ingredient that is available in the bloodstream after its consumption. For example, if you eat 100 mg of vitamin C, the detectable amount in your blood will indicate its bioavailability. The closer the bioavailability of a certain ingredient is to 100%, the more profound is its effect. This is because more of the ingredient will be able to reach its site of action. A typical site of action for active ingredients could be your muscles.
Increasing bioavailability through liposomal encapsulation
Several studies have proven the increased bioavailability of liposomal delivery systems (6,7,8). This includes encapsulation of water-soluble ingredients like Vitamin C. However, even more importantly, fat-soluble ingredients like curcumin. We can attribute the increased bioavailability to liposomes’ increased protection and absorption
Added protection due to liposomes
The protection provided by liposomes leads to a lower required dose of an active ingredient. The higher bioavailability of the ingredients means higher absorption. This decreases the possible side effects of ingredient overdosing.
Can liposomal supplements cause weight gain?
We are often asked if liposomal supplements cause weight gain. This question is asked due to the fact that liposomes are made of fatty acids. However, studies so far, have shown no such effect of phospholipids. On the contrary, phospholipids have been shown to reduce the absorption of cholesterol. Cholesterol is the molecule that makes you put on weight (9). While we can not claim that liposomes are a weight-loss remedy, we can assure you that we have not come across any studies linking an increase in body fat to liposome consumption.
Are liposomal supplements safe?
There are no known safety concerns associated with liposomal supplements. Liposomes have been a drug delivery vehicle for more than two decades now. In this time, there have been no known side effects from the liposomes themselves.
Further, the use of naturally-derived phospholipids such as sunflower or soy lecithins in the manufacture of liposomes, makes them biocompatible and non-toxic (10). Liposomes also do not elicit an immune response when administered orally, intramuscularly or intravenously.
Finally, upon digestion, various tissues can absorb the phospholipids and active ingredients from the liposomes for their metabolic potential. Those liposomal components that are not absorbed, are typically excreted through feces or urine. Thus, no unused phospholipids or nutrients circulate around the body.
Liposomal supplements are thus safe to consume.
The history of liposomal supplements
Doxil® was first approved in 1995 as liposomal doxorubicin for anti-cancer therapy (10). Since then, liposomes have shown promise as gene delivery systems for clinical gene therapy. They have also been especially beneficial for the delivery of poorly water-soluble substances. Ingredients such as curcumin, in the dietary supplement industry, greatly benefit from liposomal delivery (7).
Key takeaways about liposomal supplements:
Phospholipid Bilayers
Liposomes are synthetic phospholipid bilayer nanospheres. Phospholipids composed of water-loving phospho heads and water-repelling lipid tails, make liposomes water-soluble.
Active ingredients protection
Liposomes are good vehicles for the transport of ingredients because they protect the encapsulated ingredients from gastric digestion, increase intestinal absorption and thus increase the ingredients’ bioavailability.
Safe
Liposomes are biocompatible and non-toxic and are thus safe to consume.
References
- https://courses.lumenlearning.com/boundless-biology/chapter/lipids/. Accessed on 26 October 2020.
- Mozafari MR. Liposomes: An overview of manufacturing techniques. Cell. Mol. Bio. Letters (2005); 10: 711–719.
- Patil YP & Jadhav S. Novel methods for liposome preparation. Chem. Phys. Lipids (2014); 177: 8–18.
- Porter CJH, Trevaskis NL & Charman WN. Lipids and lipid-based formulations: optimizing the oral delivery of lipophilic drugs. Nature Reviews: Drug discovery (2007); 6: 231- 248.
- Liu W, Li D, Dong Z et al. Insight into the in vivo translocation of oral liposomes by fluorescence resonance energy transfer effect. Int. J. Pharmaceutics (2020); 587: 119682.
- Davis JL, Paris HL, Beals JW et al. Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia-Reperfusion Injury. Nutrition and Metabolic Insights (2016);9: 25–30.
- Prasad S, Tyagi AK & Aggarwal BB. Recent Developments in Delivery, Bioavailability, Absorption and Metabolism of Curcumin: The Golden Pigment from Golden Spice. Cancer Research and Treatment (2014); 46(1).
- Goktas Z, zu Y, Abbasi M et al. Recent advances in nano-encapsulation of phytochemicals to combat obesity and its comorbidities. J. Agric. Food Chem. (2020); 68 (31): 8119–8131.
- Cohn JS, Kamili A, Wat E et al. Dietary Phospholipids and Intestinal Cholesterol Absorption. Nutrients (2010); 2(2): 116–127.
- Zylberberg C & Matosevic S. Pharmaceutical liposomal drug delivery: a review of new delivery systems and a look at the regulatory landscape, Drug Delivery (2016); 23:9, 3319–3329.